The Effect of UV Light and Weather, Second Edition: On Plastics and Elastomers, 2nd Edition

Author: Liesl K. Massey

732 downloads 2460 Views 6MB Size Report

This content was uploaded by our users and we assume good faith they have the permission to share this book. If you own the copyright to this book and it is wrongfully on our website, we offer a simple DMCA procedure to remove your content from our site. Start by pressing the button below!

Report copyright / DMCA form

DOWNLOAD PDF

The Effects of

UV Light and Weather on Plastics and Elastomers Second Edition

Liesl K. Massey

Copyright © 2007 by William Andrew, Inc. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the Publisher. Plastics Design Library and its logo are owned by William Andrew, Inc. Library of Congress Cataloging-in-Publication Data Massey, Liesl K. The effects of UV light and weather on plastics and elastomers / Liesl K. Massey. -- 2nd ed. p. cm. Includes bibliographical references and index. ISBN-13: 978-0-8155-1525-8 (978-0-8155) ISBN-10: 0-8155-1525-1 (0-8155) 1. Plastics--Effect of radiation on. 2. Elastomers--Effect of radiation on. I. Title. TA455.P5M34355 2007 620.1'9232--dc22 2006018850

Printed in the United States of America This book is printed on acid-free paper. 10 9 8 7 6 5 4 3 2 1 Published by: William Andrew Publishing 13 Eaton Avenue Norwich, NY 13815 1-800-932-7045 www.williamandrew.com

NOTICE To the best of our knowledge the information in this publication is accurate; however the Publisher does not assume any responsibility or liability for the accuracy or completeness of, or consequences arising from, such information. This book is intended for informational purposes only. Mention of trade names or commercial products does not constitute endorsement or recommendation for their use by the Publisher. Final determination of the suitability of any information or product for any use, and the manner of that use, is the sole responsibility of the user. Anyone intending to rely upon any recommendation of materials or procedures mentioned in this publication should be independently satisfied as to such suitability, and must meet all applicable safety and health standards.

“To nourish children and raise them against odds is in any time, any place, more valuable than to fix bolts in cars or design nuclear weapons.” Marilyn French I dedicate this book to the wonderful man who has allowed me to realize this to be true.

William Andrew Publishing

Sina Ebnesajjad, Editor in Chief (External Scientific Advisor)

Table of Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv List of Graphs and Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 How to Use This Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weatherability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weather Defined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Variations in Natural Weathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Testing for Weatherability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elements of Weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wavelength Regions of UV Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radiation and Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radiation and Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reducing the Effect of Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Temperature and Thermal Degradation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties Post-Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UV Additives and Stabilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UV Absorbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hindered Amine Light Stabilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antioxidants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UV Inhibitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 1 1 1 1 2 2 2 3 3 3 3 4 4 5 6 6 6 6

Test Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Indoor and Interior Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Outdoor Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Accelerated Outdoor Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Conventional Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Conventional Aging with Spray . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Humidity Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Solar Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Sample Mounting Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Artificial Accelerated Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Conditions for Reproducing Natural Weathering Stresses in the Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Xenon Arc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Fluorescent or QUV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Carbon Arc or Fadeometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Notes on Variability in Testing and Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Color Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

vi

The Effects of UV Light and Weather on Plastics and Elastomers

Thermoplastics ABS Acrylonitrile-Butadiene-Styrene—Chapter 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Acrylonitrile-Styrene-Acrylate/Acrylonitrile-Butadiene-Styrene Capstock—Chapter 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Acetal Acetal—Chapter 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Weathering Properties: General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Colored Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Unpigmented Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Elevated Air Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35 35 36 36 37

Acrylonitrile-Styrene-Acrylate Acrylonitrile-Styrene-Acrylate—Chapter 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Degree of Discoloration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47 47 47 48

Acrylic Acrylic and Acrylic Copolymer—Chapter 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Acrylic and Polyvinyl Chloride Coextrusion—Chapter 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Cellulosic Plastic Cellulose Acetate Butyrate—Chapter 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Color Retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Table of Contents

vii

Fluoropolymers Fluoropolymers: Overview—Chapter 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Fluoropolymer Weathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Polytetrafluoroethylene (PTFE or TFE)—Chapter 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Fluorinated Ethylene Propylene (FEP)—Chapter 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Perfluoroalkoxy (PFA and MFA)—Chapter 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Polyvinylidene Fluoride (PVDF)—Chapter 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Polychlorotrifluoroethylene (PCTFE)—Chapter 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Ethylene-chlorotrifluoroethylene (ECTFE)—Chapter 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Ethylene-tetrafluoroethylene (ETFE)—Chapter 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Polyvinyl Fluoride (PVF)—Chapter 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Ionomer Ionomer—Chapter 17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Polyphenylene Oxide Polyphenylene Oxide—Chapter 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Weathering Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Nylon Nylon: Overview—Chapter 19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Weathering Properties: General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Weathering Properties: UV Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Weathering Properties: Colored Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

viii

The Effects of UV Light and Weather on Plastics and Elastomers

Nylon 6—Chapter 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Nylon 12—Chapter 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Nylon with Glass Fiber—Chapter 22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Nylon 66—Chapter 23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Weathering Properties: Colored Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Nylon 6,6T—Chapter 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Nylon MXD6—Chapter 25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Polyarylamide—Chapter 26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Polycarbonate Polycarbonate—Chapter 27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Light Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: UV Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

147 148 148 148

Polycarbonate Blends—Chapter 28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Weathering Properties: Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

Polyester Polybutylene Terephthalate—Chapter 29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Weathering Properties: Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

Polyethylene Terephthalate—Chapter 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

Table of Contents

ix

Liquid Crystal Polymers—Chapter 31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

Polyarylate—Chapter 32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Polyimide Polyimide—Chapter 33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Weathering Properties: General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Weathering Properties: Outer Space and Nuclear Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Polyamideimide—Chapter 34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

Polyetherimide—Chapter 35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

Polyketone Polyetheretherketone (PEEK)—Chapter 36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Polyolefin Polyethylene: Overview—Chapter 37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 Weathering Properties: General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Polyethylene Films . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Color Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: UV Stabilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

187 187 188 188 189

Low Density Polyethylene—Chapter 38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 High Density Polyethylene—Chapter 39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 Weathering Properties: Colored Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carbon Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . White Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellow Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Orange Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Blue and Green Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

195 195 195 195 196 196 197

x

The Effects of UV Light and Weather on Plastics and Elastomers

Pigment Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Part Thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

Ultrahigh Molecular Weight Polyethylene—Chapter 40 . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Polyethylene Copolymers—Chapter 41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Polypropylene—Chapter 42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Weathering Properties: Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217

Polymethylpentene—Chapter 43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Polyphenylene Sulfide Polyphenylene Sulfide—Chapter 44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

Polystyrene General Purpose Polystyrene—Chapter 45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

High Impact Polystyrene—Chapter 46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

Polysulfone Polysulfone—Chapter 47 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

Polyethersulfone—Chapter 48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

xi

Table of Contents

Styrene Acrylonitrile Copolymer Styrene-Acrylonitrile Copolymer—Chapter 49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

Styrene Butadiene Copolymer Styrene-Butadiene Copolymer—Chapter 50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 Indoor UV Light Resistance and Indirect Sunlight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247

Vinyl Resin Polyvinyl Chloride—Chapter 51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Plasticizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Plasticizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stabilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pigments and Colorants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellowing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

249 249 249 250 251 251 252 252

Chlorinated Polyvinyl Chloride—Chapter 52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

Thermoplastic Blends/Alloys ABS Vinyl Resin Alloy ABS Polyvinyl Chloride Alloy—Chapter 53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

Acrylic (PMMA) Polyvinyl Alloy—Chapter 54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

Polycarbonate ABS Alloy—Chapter 55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261

Biodegradable Thermoplastic Alloys Biodegradable Polyethylene Films Biodegradable Polyethylene Films—Chapter 56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

xii

The Effects of UV Light and Weather on Plastics and Elastomers

Degradation Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264

Starch Synthetic Resin Alloy—Chapter 57 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 Biodegradability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

Thermosets Polyester Thermoset Polyester—Chapter 58 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Polyester Powder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Urethane Polyesters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: UV Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

271 271 271 272

Polyurethane Polyurethane Reaction Injection Molding System—Chapter 59 . . . . . . . . . . . . . . . . . . . 273 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

Thermoplastic Elastomers Thermoplastic Elastomers Thermoplastic Elastomers: Overview—Chapter 60 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Chlorinate Polyethylene Elastomer—Chapter 61 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

Olefinic Thermoplastic Elastomer—Chapter 62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 Outdoor Accelerated Exposure Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285

Polyester Thermoplastic Elastomer—Chapter 63 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Weathering Properties: Color Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302

Polystyrene-Butadiene-Styrene Thermoplastic—Chapter 64 . . . . . . . . . . . . . . . . . . . . . . 311 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

Styrenic Thermoplastic Elastomer—Chapter 65 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313

xiii

Table of Contents

Weathering Properties: Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

Urethane Thermoplastic Elastomer—Chapter 66 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 Weathering Properties: UV Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

Nitrile Thermoplastic Elastomers—Chapter 67 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324

Thermosetting Elastomers (Rubbers) Thermoset Elastomers or Rubbers Thermoset Elastomers or Rubbers: Overview—Chapter 68 . . . . . . . . . . . . . . . . . . . . . . . 325 Butyl Rubber, Bromobutyl Rubber, and Chlorobutyl Rubber—Chapter 69 . . . . . . . . 327 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 Weathering Properties: Ozone Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Chlorosulfonated Polyethylene Rubber—Chapter 70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Color Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Curing Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Fillers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties: Plasticizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

329 329 330 331 332 332

Ethylene-Propylene Copolymer—Chapter 71 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343

Ethylene-Propylene Diene Methylene Terpolymer—Chapter 72 . . . . . . . . . . . . . . . . . . . 345 UV Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outdoor Weather Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accelerated Outdoor Weathering Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accelerated Artificial Weathering Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effect of Carbon Black on Weatherability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effect of Color Pigments on Weatherability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effective UV Screening Agents in Mineral-Filled Vulcanizates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effect of Curing Systems on Weatherability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effect of Plasticizers on Weatherability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ozone Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

345 345 346 347 347 347 348 348 348 348

Neoprene Rubber—Chapter 73 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374

xiv

The Effects of UV Light and Weather on Plastics and Elastomers

Polybutadiene—Chapter 74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384

Polyisoprene Rubber—Chapter 75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386

Polyurethane—Chapter 76 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 Weathering Properties: Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392

Silicone Rubber—Chapter 77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 Weathering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 Weathering Properties by Material Supplier Trade Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393

Fluoropolymers in Coating Applications—Appendix 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 Architectural Fabrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fabric Base Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fabric Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fabric Top Finishes or Topcoats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weathering Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

395 395 395 395 396

Coil Coatings—Appendix 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 Comparative Properties and Performance Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 Coil Coating Topcoats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399

Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trade Name Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Plastics Design Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

401 445 453 455

Preface Welcome to the Second Edition of The Effects of UV Light and Weather on Plastics and Elastomers, an extensive compilation on how the elements of weathering affect the properties and characteristics of plastics and elastomers. Designed as a reference handbook, this edition presents data in a format that allows the user to easily compare and contrast performance characteristics between different polymer families and, where possible, between the products available within a material family itself. Information was compiled from many different sources: material manufacturers, technical journals, and papers, etc. Extensive and detailed references are provided to further research materials and material applications. Amajor contributing factor to the outdoor weathering (degradation) of polymers is UV light. Temperature, moisture, and pollutants combine with the UV light and degrade polymers by different mechanisms. Design and application engineers and scientists need to know how a material will perform under various conditions. The level of deterioration expected and accepted varies by application and end use. In many instances, the application for which the material is intended has a group or society that has provided standardized tests for evaluating the materials (e.g., the Society of Automotive Engineers provides the SAE Test Methods. ASTM International publishes extensive weathering test methods often referenced by users and manufacturers of outdoor-oriented materials. The introductory chapter is designed to provide basic information on the components of weathering, material properties affected by weathering, and a review of the most common testing environments. Brief discussions of weathering stabilizers as well as color stability are included. The body of this edition presents discussion and results of weathering and outdoor exposure testing. Each of the seventy-seven chapters represents a specific material family, and the information relating to

that material is provided in textual, graphical, and tabular form. Textual information provides discussion of the material’s susceptibility or immunity to weathering or its components as well as discussion of test results. Graphical and tabular representation of data allows the user to quantitatively understand the material’s performance under specific criteria or multiple test methods. Information is included for as many materials, tests, and conditions as possible. Even where detailed metadata are not available, general information is provided. It should be noted that the content of the material chapters is representative rather than all-inclusive. That is, a polymer’s performance is presented in as much detail as possible from the sources available. All manufacturers of all outdoor materials are not included due to obvious space limitations. At the end of this book extensive references are provided in the event that further research and study are warranted. It is my hope that this reference handbook is the first book to which a designer, engineer, or scientist refers when looking for general weathering properties and comparing properties between families of polymers. However, this reference handbook should not serve as a substitute for actual testing to determine the suitability of a material for use. Please contact the manufacturers of these materials for the latest and most complete material and performance information. A special word of thanks to those who have allowed their information and test data to be included in this book. Every effort was made to present the information in its original context. As always, your feedback as a reader and user of this information is appreciated and encouraged.

Liesl K. Massey

2006

List of Graphs and Tables List of Graphs 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 1-12 1-13 1-14 1-15 1-16 1-17 1-18 1-19 1-20 1-21 1-22 1-23 1-24 1-25 1-26 1-27

Changes in Material Characteristics due to Photo-Oxidation of ABS . . . . . . . . . . . . . . . . . Outdoor Weathering Exposure Time vs. Yellowness Index of ABS . . . . . . . . . . . . . . . . . . . . Arizona Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS . . . Arizona Outdoor Weathering Exposure Time vs. Elongation of ABS . . . . . . . . . . . . . . . . . . Arizona Outdoor Weathering Exposure Time vs. Tensile Strength at Yield of ABS . . . . . . Arizona Outdoor Weathering Exposure Time vs. E Color Change of ABS . . . . . . . . . . . Arizona, Florida, and Ohio Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Florida Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS . . . . Florida Outdoor Weathering Exposure Time vs. Drop Weight Impact of ABS . . . . . . . . . . Florida Outdoor Weathering Exposure Time vs. E Color Change of ABS . . . . . . . . . . . . Florida Weathering Exposure Time vs. Chip Impact Strength of ABS (White Rovel Capstock and Acrylic Capstock) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Florida Weathering Exposure Time vs. Chip Impact Strength of ABS (Natural Resin) . . . Ohio Outdoor Weathering Exposure Time vs. E Color Change of ABS . . . . . . . . . . . . . . Ohio Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS . . . . . . Okinawa, Japan, Outdoor Weathering Exposure Time vs. E Color Change of ABS . . . Okinawa, Japan, Outdoor Weathering Exposure Time vs. Dynstat Impact Strength Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Okinawa, Japan, Outdoor Weathering Exposure Time vs. Elongation at Break Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Okinawa, Japan, Outdoor Weathering Exposure Time vs. Gloss Retained of ABS . . . . . West Virginia Outdoor Weathering Exposure Time vs. Falling Dart Impact of ABS at −40◦ C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Virginia Outdoor Weathering Exposure Time vs. Falling Dart Impact of ABS at 23◦ C, −25◦ C, and −40◦ C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Virginia Outdoor Weathering Exposure Time vs. Falling Dart Impact of ABS at 23◦ C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Virginia Outdoor Weathering Exposure Time vs. Flexural Modulus Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Virginia Outdoor Weathering Exposure Time vs. Flexural Strength of ABS at −40◦ C and 23◦ C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Virginia Outdoor Weathering Exposure Time vs. Flexural Strength Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Virginia Outdoor Weathering Exposure Time vs. Izod Impact Strength Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Virginia Outdoor Weathering Exposure Time vs. Tensile Strength Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sunshine Weatherometer Exposure Time vs. Dynstat Impact Strength Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29

xviii 1-28 1-29 1-30 1-31 1-32 1-33 2-1 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 3-10 3-11 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10

The Effects of UV Light and Weather on Plastics and Elastomers Sunshine Weatherometer Exposure Time vs. Elongation at Break Retained of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sunshine Weatherometer Exposure Time vs. Gloss Retained of ABS . . . . . . . . . . . . . . . . Weatherometer Exposure Time vs. Impact Strength of ABS . . . . . . . . . . . . . . . . . . . . . . . . . Xenotest 1200 Exposure Time vs. Impact Strength of ABS . . . . . . . . . . . . . . . . . . . . . . . . . . Accelerated Indoor UV Exposure Time vs. E Color Change of ABS . . . . . . . . . . . . . . . . Yellowness Index of UVA- and HALS-Stabilized ABS after Outdoor Weathering in Switzerland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after Arizona, Florida, and New York Outdoor Weathering of GE Plastics Cycolac® /Geloy® Resin Systems Compared to PVC . . . . . . . . . . . . . . . . . . . . . . . . Relative Tensile Strength after Accelerated Interior Weathering According to SAE J1885 for Dupont Delrin® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relative Gloss after Accelerated Interior Weathering According to SAE J1885 for DuPont Delrin® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Changes in Mechanical Properties after Light Exposure of Ticona Celcon® UV90Z . . . . Outdoor Exposure Time vs. Impact Strength Retained of BASF Ultraform® N 2320 and Ultraform® N 2325 U Acetal Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . New Jersey and Arizona Outdoor Exposure Time vs.Tensile Impact Strength of Ticona Celcon® M90 and UV90 Acetal Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . New Jersey and Arizona Outdoor Exposure Time vs.Tensile Strength atYield of Ticona Celcon® M90 Acetal Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . New Jersey Outdoor Exposure Time vs. Tensile Strength at Yield of Ticona Celcon® GC25 A Acetal Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . QUV Exposure Time vs. E Color Change of Ticona Celcon® Acetal Copolymer . . . . . . Sunshine Weatherometer Exposure Time vs. Elongation Retained of Mitsubishi Iupital® F20 Acetal Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sunshine Weatherometer Exposure Time vs. Tensile Strength Retained of Mitsubishi Iupital® F20 Acetal Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Xenon Arc Weatherometer Exposure Time vs. Relative Gloss of BASF Ultraform® N Acetal Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellowness Index after Outdoor Exposure for BASF Luran® S 797 and Luran® S 776 ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impact Strength Retained after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elongation at Break Retained after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gloss Retained after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impact Strength Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® T110 and T120 ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impact Strength Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elongation at Break Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gloss Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® T115 and T110 ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gloss Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29 30 30 31 31 32 33 40 40 41 41 42 42 43 43 44 44 45 49 50 50 51 51 52 52 53 53 54

List of Graphs and Tables 4-11 4-12 4-13 4-14 5-1 5-2 5-3 5-4 5-5 5-6 5-7 7-1 7-2 7-3 8-1 10-1 11-1 11-2 11-3 12-1 12-2 12-3 12-4 12-5 13-1 13-2 13-3

Impact Strength after Weatherometer Exposure for BASF Luran® S ASA Polymer at Different Test Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impact Strength after Xenotest 1200 Exposure for BASF Luran® S 797 and Luran® S 776 ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellowness Index of ABS, Luran® S, and Blends after Exposure to Sunshine . . . . . . . . . . Penetration Energy after Exposure to Sunshine on 2-mm Thick Disks of Luran® S 778 T, Luran® S 778 T UV, Luran® S KR 2861/1 C, ABS-UV, and PC+ABS . . . . . . . . . . . Light Transmission for Acrylic, Cyrolon® UVP Polycarbonate Sheet, and Polycarbonate after Weathering Exposure as per ASTM D1003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellowness Index for Acrylic, Cyrolon® UVP Polycarbonate Sheet, and Polycarbonate after Weathering Exposure as per ASTM D1925 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Percentage Haze for Acrylic, Cyrolon® UVP Polycarbonate Sheet, and Polycarbonate after Weathering Exposure as per ASTM D1003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Luminous Transmittance, Haze, Yellowness Index, and Surface Gloss of Plexiglas® V825 after Florida and Arizona Weathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Luminous Transmittance, Haze, Yellowness Index, and Surface Gloss of Plexiglas® DR101 after Florida and Arizona Weathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Luminous Transmittance, Haze, Yellowness Index, and Surface Gloss of Plexiglas® V920 after Florida and Arizona Weathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after Atlas Weatherometer Exposure of Novacor NAS® 30, NAS® 36, Zylar® 533, and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength at Break after Arizona Weathering for Eastman Tenite® Butyrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elongation at Break after Arizona Weathering for Eastman Tenite® Butyrate . . . . . . . . . . Impact Strength after Weathering for Eastman Tenite® Butyrate . . . . . . . . . . . . . . . . . . . . . Mechanical Properties of PVDF, ETFE, and PVF Films after South Florida Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Retention of Tensile Strength and Percentage Elongation after Outdoor Exposure for DuPont FEP Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after Carbon Arc Weatherometer Accelerated Weathering (Dew Cycle) for PFA and MFA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength Retention after Carbon Arc Weatherometer Accelerated Weathering (Dew Cycle) for PFA and MFA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elongation Retention after Carbon Arc Weatherometer Accelerated Weathering (Dew Cycle) for PFA and MFA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Retention of Tensile Strength and Elongation after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for PVDF Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for Solvay Solexis Hylar® 5000 PVDF Pigmented Coatings . . . . . . . . . . . . . . . . . . . Gloss Retention after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for Solvay Solexis Hylar® 5000 PVDF Pigmented Coatings . . . . . . . . . . . . . . . . . . . . . . . . . Chalk Rating after Florida Exposure (45◦ Angle South) for Commercial White Paints . . . Gloss Retention after Florida Exposure (45◦ Angle South) for Commercial White Paints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elongation Retained in the Machine Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elongation Retained in the Transverse Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength Retained in the Machine Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xix

54 55 55 56 59 59 60 61 62 63 63 68 68 69 71 77 79 80 80 84 84 85 85 86 87 88 88

xx

The Effects of UV Light and Weather on Plastics and Elastomers

13-4

Tensile Strength Retained in the Transverse Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1 Retention of Tensile Strength and Elongation after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for Solvay Solexis Halar® ECTFE Film . . . . . . . . . . . . . . . . . . 14-2 Retention of Tensile Strength and Elongation after QUV Accelerated Weathering Exposure, UVB-313, for Solvay Solexis Halar® ECTFE Film . . . . . . . . . . . . . . . . . . . . . . . . 14-3 Color Change, E, after QUV Accelerated Weathering Exposure, UVB-313, for Solvay Solexis Halar® ECTFE Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-1 Percentage of Initial Properties Retained after South Florida Weathering Exposure at an Angle of 45◦ Facing South for DuPont Tedlar® PVF Film . . . . . . . . . . . . . . . . . . . . . . . . . 16-2 Percentage Gloss Retention after South Florida Weathering Exposure at an Angle of 45◦ Facing South for DuPont Tedlar® PVF Film and Pigmented Vinyl Film . . . . . . . . . . . . 16-3 Average Rate of UV Absorber Degradation in Free-Standing DuPont Tedlar® PVF Film after Florida Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-4 Color Stability of DuPont Tedlar® PVF Film after Exposure to Atlas Sunshine Arc Weatherometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-5 Percentage of Initial Properties Retained after Atlas Sunshine Arc Weatherometer Exposure of DuPont Tedlar® PVF Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-6 Typical Color Change Range of a Variety of Pigmented DuPont Tedlar® SP Films after Xenon Arc Exposure as per the SAE J1960 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-7 Gloss Retention of Refinish Paint, Gel Coat, and DuPont Tedlar® SP Film after Xenon Arc Exposure as per the SAE J1960 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-8 Gloss Retention of Acrylic Film, ASA/AES Copolymer, and DuPont Tedlar® SP Film after Xenon Arc Exposure as per the SAE J1960 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-1 Change in Color, E, after Accelerated Indoor UV Exposure of Modified PPO . . . . . . . . 18-2 Dart Drop Impact Strength after Arizona Outdoor Weathering Exposure of Modified PPO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-3 Percentage Elongation after Arizona Outdoor Weathering Exposure of Modified PPO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-4 Tensile Strength after Arizona Outdoor Weathering Exposure of Modified PPO . . . . . . . . 18-5 Change in Color, E, after Arizona Outdoor Weathering Exposure of Modified PPO . . . 18-6 Change in Color, E, after Ohio Outdoor Weathering Exposure of Modified PPO . . . . . 18-7 Dart Drop Impact Strength after Ohio Outdoor Weathering Exposure of Modified PPO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1 Elongation at Break after Outdoor Exposure for Ube Ube® Nylon 6 . . . . . . . . . . . . . . . . . . 20-2 Flexural Modulus after Outdoor Exposure for Ube Ube® Nylon 6 . . . . . . . . . . . . . . . . . . . . 20-3 Notched Izod Impact Strength after Outdoor Exposure for Ube Ube® Nylon 6 . . . . . . . . . 20-4 Tensile Strength after Outdoor Exposure for Ube Ube® Nylon 6 . . . . . . . . . . . . . . . . . . . . . 20-5 Flexural Strength at Break after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6 . . . 20-6 Flexural Modulus after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6 . . . . . . . . . . . . 20-7 Notched Izod Impact Strength after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-8 Weight Change after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6 . . . . . . . . . . . . . 20-9 Flexural Strength after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6 . . . . . . . . . . . . 20-10 Tensile Strength after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6 . . . . . . . . . . . . . 20-11 Elongation after Sunshine Weatherometer Exposure of Nylon 6 . . . . . . . . . . . . . . . . . . . . . 20-12 Tensile Strength after Sunshine Weatherometer Exposure of Nylon 6 . . . . . . . . . . . . . . . . 21-1 Change in Color, E, after Weatherometer Exposure of EMS Grilamid® TR 55, TR 55 LX, TR 90, and TR 90 UV Nylon 12 Compared to Other Polymers . . . . . . . . . . . . . . . . . . .

89 92 92 93 98 98 99 99 100 100 101 101 110 111 111 112 112 113 113 119 120 120 121 121 122 122 123 123 124 124 125 128

List of Graphs and Tables Yellow Index (YI) after Weathering Exposure as per ASTM D1975 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-3 Tensile Impact Strength after Weatherometer Exposure for EMS Grilamid® TR 55, TR 55 LX, and TR 55 LY Nylon 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-4 Tensile Impact Strength after Weatherometer Exposure for EMS Grilamid® TR 90 and TR 90 UV Compared to Other Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-5 Tensile Impact Strength Half-Life after Weathering for EMS Grilamid® TR 90, TR 90 LX, and TR 90 UV Compared to Other Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-6 Yield Strength after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-7 Percentage Retention of Yield Strength after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX . . . . . . . . . . . . . . . . . . . . . . . . . 21-8 Percentage Retention of Elongation at Break after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX . . . . . . . . . . . . . . . . . . 21-9 Percentage Retention of Work to Break after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, and TR 55 LX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-10 Transparency of EMS Grilamid® and EMS Grivory® Compared to Glass and Other Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-11 Transparency in the Visible Spectrum of EMS Grilamid® Compared to Other Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-1 Flexural Modulus after Outdoor Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-2 Notched Izod Impact Strength after Outdoor Weathering Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-3 Flexural Strength after Outdoor Weathering Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-4 Tensile Strength after Outdoor Weathering Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-5 Elongation (%) after Sunshine Weatherometer Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-6 Tensile Strength after Sunshine Weatherometer Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-1 Flexural Strength after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-2 Flexural Modulus after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-3 Notched Izod Impact Strength after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-4 Weight Change after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27-1 Light Transmission of UV-Stabilized GE Plastics Lexan® . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27-2 Light Transmission of Transparent GE Plastics Lexan® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27-3 Transmittance through Transparent GE Plastics Lexan® after Florida Outdoor Exposure as per ASTM G7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27-4 Yellowness Index after Florida Outdoor Exposure as per ASTM G7 for GE Plastics Lexan® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27-5 Haze after Accelerated Outdoor Exposure of Coated and Uncoated Transparent GE Plastics Lexan® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27-6 Yellowness Index after Accelerated Outdoor Exposure of Coated and Uncoated Transparent GE Plastics Lexan® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xxi

21-2

128 129 129 130 130 130 131 131 132 132 139 140 140 141 141 142 144 144 145 145 152 152 153 153 153 154

xxii 27-7 27-8 27-9 27-10 27-11 27-12 27-13 27-14 28-1

28-2

28-3 29-1 29-2 29-3 29-4 29-5 29-6 29-7 29-8 30-1 30-2 33-1 33-2 33-3 33-4 33-5 33-6 34-1 34-2 35-1

The Effects of UV Light and Weather on Plastics and Elastomers Yellowness Index after Xenon Arc Weathering for GE Plastics Lexan® . . . . . . . . . . . . . . . . Change in Yellowness Index, YI, after Whirlygig Accelerated Outdoor Exposure of GE Plastics Lexan® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellowness Index after Kentucky Outdoor Weathering for GE Lexan® S-100 Sheet . . . . . Yellowness Index after EMMAQUA Accelerated Arizona Weathering for GE Lexan® S-100 Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Haze (%) after Carbon Arc XW Weathering for GE Lexan® 153 . . . . . . . . . . . . . . . . . . . . . Yellowness Index after Twin Carbon Arc Weathering for GE Lexan® S-100 Sheet . . . . . . Yellowness Index after Outdoor Weathering for PC Natural and UV Stabilized with Tinuvin® 234 Benzotriazole UV Absorber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gloss (20◦ ) Retention after Xenon Arc Weathering of Twin Wall PC Sheets (10 mm) Stabilized with Tinuvin® UV Absorbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, of Pigmented GE Plastics Cycoloy® C1100 PC/ABS after Accelerated UV Exposure as per SAE J1885 (ATLAS Ci65XW) and DIN75202 (XENON450) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, of Pigmented GE Plastics Cycoloy® C1100 PC/ABS after Accelerated UV Exposure as per SAE J1885 (ATLAS Ci65XW) and DIN75202 (XENON450) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Development after Xenon Arc Weatherometer Exposure of PC/ABS (50/50) Blend with Tinuvin® 234 UV Stabilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notched Izod Impact Strength after Florida and Arizona Outdoor Weathering for Ticona Celanex® PBT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Florida and Arizona Outdoor Weathering for Ticona Celanex® PBT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flexural Strength at Break after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flexural Modulus after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester . . . . . . . . Notched Izod Impact Strength after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weight Change after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester . . . . . . . . . . Tensile Strength Retained after Weatherometer Exposure of Ticona Celanex® PBT . . . . Change in Yellowness Index, YI, after Light Exposure of PBT Injection-Molded Plaques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Sunshine Weatherometer Exposure of PET . . . . . . . . . . . . . . . . . . . Elongation after Sunshine Weatherometer Exposure of PET . . . . . . . . . . . . . . . . . . . . . . . . Ultimate Elongation after Florida Aging of DuPont Kapton® Film . . . . . . . . . . . . . . . . . . . . . Ultimate Elongation after Atlas Weatherometer Exposure of DuPont Kapton® . . . . . . . . . Elongation Retained after Sunshine Weatherometer Exposure for UBE Upilex® R and UBE Upilex® S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flexural Strength Retained after Sunshine Weatherometer Exposure for UBE Upimol® R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength Retained after Sunshine Weatherometer Exposure for UBE Upilex® R and UBE Upilex® S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flexural Strength Retained after UV-CON Exposure for UBE Upimol® R . . . . . . . . . . . . . . Elongation after Atlas Sunshine Carbon Arc Weatherometer Exposure for Torlon® 4203L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Atlas Sunshine Carbon Arc Weatherometer Exposure for Torlon® 4203L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Xenon Arc Weatherometer Exposure of GE Plastics Ultem® 1000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

154 154 155 155 156 156 157 157

159

160 160 162 162 163 163 164 164 165 165 171 172 177 178 178 179 179 180 181 182 183

List of Graphs and Tables Retention of Elongation after Atlas Weatherometer Exposure of High Density Polyethylene (HDPE) Plaques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37-2 Impact Strength Retained after Atlas Weatherometer Exposure of Linear Low Density Polyethylene (LLDPE) Plaques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37-3 Kilolangleys of Exposure to Create 50% Tensile Strength Retained after Arizona Outdoor Exposure of HDPE-Pigmented Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37-4 Tensile Strength after Arizona Exposure of 0.96 Density Unstabilized Polyethylene with Various Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-1 Tensile Strength after Arizona Outdoor Weathering of Yellow Chevron Phillips Marlex® HDPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-2 Tensile Strength after Weatherometer Exposure of Yellow Chevron Phillips Marlex® HDPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-3 Tensile Strength after Weatherometer Exposure of Red Chevron Phillips Marlex® HDPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-4 Tensile Strength after Weatherometer Exposure of Unstabilized Red Chevron Phillips Marlex® HDPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-5 Tensile Strength after Weatherometer Exposure of Orange Chevron Phillips Marlex® HDPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-6 Tensile Strength after Weatherometer Exposure of Blue Chevron Phillips Marlex® HDPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-7 Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with 2% Zinc Oxide and 2% TiO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-8 Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with Varying Concentrations of TiO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-9 Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with 1% TiO2 and UV Stabilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-10 Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with Various Degrees of Pigment Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-1 Kilolangleys to 50% Retained Tensile Strength and Days to Embrittlement after 45◦ South Florida and Oven Aging at 120◦ C of UV-Stabilized Polypropylene Plaques . . . . . . 42-2 Surface Roughness after 45◦ South Florida Weathering Exposure of UV-Stabilized Polypropylene Plaques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-3 Color Change, E, after Accelerated Weathering for UV-Stabilized Polypropylene Automotive Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-1 Izod Impact Strength Retained after Weatherometer Exposure for Mitsui TPX™ RT18 Polymethylpentene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-1 Yellowness Index after Atlas Fadeometer Exposure of General Purpose Polystyrene . . . 45-2 Yellowness Index after Fluorescent Lamp Exposure of BASF Polystyrol® General Purpose Polystyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-1 Yellowness Index after Fadeometer Exposure of Dow Styron® Impact and Flame-Retardand Polystyrene and Dow Styron® Unmodified Polystyrene . . . . . . . . . . . . . 46-2 Color Change, E, after Florida Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-3 Color Change, E, after Arizona Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-4 Color Change, E, after Kentucky Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-5 Color Change, E, after Illinois Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xxiii

37-1

191 191 192 192 205 205 206 206 207 207 208 208 209 209 220 221 221 223 229 229 233 234 234 235 235

xxiv

The Effects of UV Light and Weather on Plastics and Elastomers

46-6

Impact Property Retention, Energy at Maximum Load, after 3000 hours of Atlas Weather-Ometers® Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-7 Impact Property Retention, Total Energy, after 3000 hours of Atlas Weather-Ometers® Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . 46-8 Impact Property Retention, Maximum Load, after 3000 hours of Atlas WeatherOmeters® Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . 46-9 Impact Strength after Xenon Arc Weathering of HIPS as per ISO 4892-2 . . . . . . . . . . . . . 46-10 Yellowness Index after Xenon Arc Weathering of HIPS as per ISO 4892-2 . . . . . . . . . . . . 47-1 Tensile Strength after Xenon Arc Weatherometer Exposure of Polysulfone . . . . . . . . . . . . 48-1 Tensile Strength after Xenon Arc Weatherometer Exposure of PES . . . . . . . . . . . . . . . . . . 49-1 Yellowness Index after Arizona Outdoor Weathering of Dow Tyril® SAN Copolymer . . . . 49-2 Yellowness Index after UV-CON Accelerated Weathering Exposure of SAN Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51-1 Elongation after Xenon Exposure of Various UV Stabilized PVC Formulations . . . . . . . . 51-2 Elongation Retention after Xenon Exposure of Various UV-Stabilized PVC Formulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51-3 Yellowness Index after Xenon Exposure of Various UV-Stabilized PVC Formulations . . . 52-1 Drop Weight Impact Strength Retained after Florida Outdoor Weathering Exposure of CPVC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56-1 Weight Loss of Mater-Bi Biodegradable Film after Burying in Various Soils . . . . . . . . . . . 56-2 Elongation Retained after Xenon Weatherometer Exposure of Starch-Modified Low Density Polyethylene (LDPE) Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56-3 Elongation Retained after Composing of Starch-Modified LDPE Film . . . . . . . . . . . . . . . . 56-4 Starch Content Retained after Burial of Ecostar Starch-Modified PE Film . . . . . . . . . . . . . 58-1 Yellowness Index after Xenon Arc Weathering of Unsaturated Polyester . . . . . . . . . . . . . . 59-1 Change in color, b, after Florida Outdoor Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System and Aromatic Polyurethane . . . . . . . . . . . . . . . . . . . 59-2 Gloss Retained after QUV Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59-3 Gloss Retained after Sunshine Carbon Arc Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59-4 Results of Visual Inspection after EMMAQUA Accelerated Exposure of Recticel Colo-Fast® Polyurethane RIM System and Several Other Materials . . . . . . . . . . . . . . . . . . 62-1 Carbonyl Formation after Xenon Arc Weatherometer Exposure of Dow Chemical Company’s Engage™ Olefinic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-2 Decrease in Molecular Weight after Xenon Arc Weatherometer Exposure of Dow Chemical Company’s Engage™ Olefinic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . 66-1 Elongation after QUV Exposure of Dow Pellethane® 2103-80 AEF Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66-2 Tensile Strength after QUV Exposure of Dow Pellethane® 2103-80 AEF Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66-3 Yellowness Index after QUV Exposure of Dow Pellethane® 2103-80 AEF Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66-4 Yellowness Index after QUV Exposure of BASF Elastollan® 1185A-10 Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66-5 Tensile Strength after Xenon Weatherometer Exposure of BASF Elastollan® 1185A-10 Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-1 Elongation at Break after Delaware Outdoor Exposure for DuPont Elastomers Hypalon® 20 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

236 236 237 237 238 240 241 244 245 253 253 254 255 265 266 266 267 272 276 277 277 278 298 299 320 320 321 321 322 341

List of Graphs and Tables

xxv

71-1 71-2

343

72-1 72-2 76-1 A1-1 A1-2 A1-3

Carbonyl Formation after Xenon Arc Exposure for Ethylene-Propylene Copolymer . . . . Decrease in Molecular Weight after Xenon Arc Exposure for Ethylene-Propylene Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carbonyl Formation after Xenon Arc Weatherometer Exposure of EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Decrease in Molecular Weight after Xenon Arc Weatherometer Exposure of EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Change in Color, b, after Florida Outdoor Weathering of Polyurethane . . . . . . . . . . . . . . Top Finish Thickness after Accelerated Florida Outdoor Exposure Testing for Acrylic, PVDF, and DuPont Tedlar® PVF Top Finishes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after Accelerated Florida Outdoor Exposure Testing for Acrylic, PVDF, and DuPont Tedlar® PVF Top Finishes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gloss Change, 60◦ Gloss, after Accelerated Florida Outdoor Exposure Testing for Acrylic, PVDF, and DuPont Tedlar® PVF Top Finishes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

344 372 372 392 397 397 398

List of Tables 1-1 1-2 1-3 1-4 3-1 3-2 3-3 3-4 3-5 3-6 3-7 4-1 4-2 4-3 5-1 5-2 5-3 9-1 10-1 10-2

Outdoor Weathering of White ABS in Florida . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outdoor Weathering of ABS in Ludwigshafen, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accelerated Indoor Exposure of GE Plastics Cycolac® VW300 ABS by HPUV . . . . . . . . Accelerated Indoor Exposure of GE Plastics Cycolac® KJB ABS to Fluorescent Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Differences, E, after Light Exposure for Pigmented Ticona Celcon® UV90Z (GM and Ford Automotive Colors) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Differences, E, after Light Exposure for Pigmented Ticona Celcon® UV90Z . . . . Color Differences, E, after Light Exposure for Unpigmented Ticona Celcon® M90UV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Differences, E, after Florida Weathering for Ticona Hostaform® Materials . . . . . . Color Differences, E, after Xenotest 1200 for Ticona Hostaform® C 9021 LS Blue 80/4065 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength and Elongation after Arizona Weathering Exposure for DuPont Delrin® 507 BK601 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength and Elongation after Michigan Weathering Exposure for DuPont Delrin® 507 BK601 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Properties after Florida (45◦ South Facing) Outdoor Exposure for Pigmented GE Plastics Geloy® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Long-Term Material Performance for GE Plastics Geloy® . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellowness Index after Outdoor Weathering in Ludwigshafen, Germany, for BASF Luran® S 776 S ASA Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cyro Acrylite® GP F Acrylic Sheet after Xenon Arc Accelerated Weathering . . . . . . . . . . Cyro Acrylite® GP FL Acrylic Sheet after Xenon Arc Accelerated Weathering . . . . . . . . . Cyro Acrylite® GP FLW Acrylic Sheet after Xenon Arc Accelerated Weathering . . . . . . . Mechanical Properties of PTFE Film after South Florida Exposure . . . . . . . . . . . . . . . . . . Mechanical Properties after 20-Year South Florida Exposure for Two Thicknesses of FEP Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength and Break Elongation after 20-Year South Florida Exposure for Two Thicknesses of FEP Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14 14 15 15 37 37 38 38 38 39 39 48 48 49 58 58 58 73 75 76

xxvi 10-3 10-4 10-5 12-1 12-2 12-3 12-4 14-1 15-1 17-1 17-2 17-3

17-4

17-5 18-1

20-1 20-2 22-1 27-1 27-2 27-3

27-4 27-5 30-1

The Effects of UV Light and Weather on Plastics and Elastomers Material Properties (Dielectric Strength, Tensile Strength, Elongation at Break, and MIT Flex Life) of FEP Film after South Florida Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties (Tensile Strength and Elongation at Break) of FEP Film after South Florida Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electrical Properties of FEP Film after South Florida Exposure . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties and Yellowness Index after Arizona Outdoor Weathering Exposure for Solvey Solexis Solef ® 11010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellowness Index after QUV Accelerated Weathering Exposure (UV-B 313) for Solvey Solexis Solef ® 21508 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Retention of Mechanical Properties after Outdoor Weathering of Arkema Kynar® PVDF Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Retention of Mechanical Properties after Xenon Arc Weatherometer Exposure of PVDF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accelerated Weathering of Solvay Solexis Halar® ECTFE in a Xenon Arc Weatherometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accelerated Weathering of DuPont Tefzel® 200 ETFE in a Weatherometer . . . . . . . . . . . . Physical Properties and Visual Appearance after Florida and Arizona Outdoor Weathering for UV-Stabilized DuPont Surlyn® Ionomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physical Properties and Visual Appearance after Accelerated Weathering in an Atlas Weatherometer for Zinc Ion Type UV-Stabilized DuPont Surlyn® Ionomer . . . . . . . . . . . . . Physical Properties and Visual Appearance after Accelerated Weathering in an Atlas Weatherometer for Zinc Ion Type UV- and Antioxidant-Stabilized, Pigmented DuPont Surlyn® Ionomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physical Properties and Visual Appearance after Accelerated Weathering in an Atlas Weatherometer for Sodium Ion Type UV- and Antioxidant-Stabilized, Pigmented DuPont Surlyn® Ionomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physical Properties and Visual Appearance after Accelerated Weathering in a QUV Weatherometer for Zinc Ion Type DuPont Surlyn® Ionomer . . . . . . . . . . . . . . . . . . . . . . . . . . Change in Yellowness Index and Percentage Gloss Retained after Outdoor Weathering Exposure in Arizona, Florida, and New York for GE Plastics Noryl® Modified PPO. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after Outdoor Weathering Exposure in Florida for BASF Capron® Nylon 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after Outdoor Weathering Exposure in California and Pennsylvania for LNP Engineering Plastics® Nylon 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties Retained after Outdoor Weathering in California and Pennsylvania for LNP (a Division of GE Plastics) Glass-Reinforced Nylon 610 . . . . . . . . . . . . . . . . . . . . . Izod Impact and Surface and Appearance Properties after Arizona Outdoor Exposure of Dow Calibre® 300 6 MFR without and with UV Stabilizer . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after California and Pennsylvania Outdoor Exposure of LNP Engineering Plastics PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties and Surface and Appearance Properties after Arizona Accelerated Outdoor Weathering and Kentucky Outdoor Weathering for GE Lexan® S-100 and Lexan® 100 Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after XW Accelerated Weathering for GE Lexan® 303 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Change in color, E, after Accelerated Indoor Exposure of GE Lexan® 920A by HPUV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength and Elongation Retained after Arizona Outdoor Weathering of DuPont Rynite® 545 NC10, Rynite® 545 BK504, and Rynite® 935 BK505 . . . . . . . . . . . .

76 76 77 82 82 83 83 91 95 104 105

106

107 108

110 118 119 133 148 149

150 151 151 168

List of Graphs and Tables 30-2 30-3 30-4 30-5

31-1 36-1 36-2 37-1 37-2 37-3 39-1 39-2 39-3 39-4 39-5 39-6 39-7 41-1 42-1 42-2 42-3 42-4 42-5 44-1 45-1

Tensile Strength and Elongation Retained after Arizona Outdoor Weathering of DuPont Rynite® 530 NC10 and Rynite® 530 BK503 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength and Elongation Retained after Florida Outdoor Weathering of DuPont Rynite® 530 NC10 and Rynite® 530 BK503 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength and Elongation Retained after Florida Outdoor Weathering of DuPont Rynite® 545 NC10 and Rynite® 545 BK504 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength and Elongation Retained after Arizona EMMA and EMMAQUA Weathering of DuPont Rynite® 530 NC10, Rynite® 530 BK503, Rynite® 545 NC10, and Rynite® 545 BK504 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after Xenon Arc Accelerated Weathering for Ticona Vectra® A950, Vectra® A130, Vectra® B950, and Vectra® A540 . . . . . . . . . . . . . . . . . . . . . . Tensile Strength Retained after United Kingdom Outdoor Weathering Exposure of Natural, Black, and White Pigmented Victrex® PEEK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength Retained after United Kingdom Outdoor Weathering Exposure of Pigmented Victrex® PEEK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Life after Outdoor Weathering for Cyanox 2777, Cyasorb UV 531, and Cyasorb UV-3346 UV-Stabilized Polyethylene Greenhouse Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Life after Outdoor Weathering for Cyasorb UV-3346 UV-Stabilized Polyethylene Greenhouse Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after California and Pennsylvania Outdoor Exposure of Glass-Reinforced LNP Polyethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after EMMA Accelerated Weathering of Chevron Phillips Marlex® HDPE with Channel Black and Furnace Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with Various Degrees of Pigment Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with UV Absorber and Various Orange Pigment Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with 2% Cadmium Yellow Pigment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with UV Absorber and Various Yellow Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with 2% TiO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface and Appearance after Accelerated Weathering of Chevron Phillips Marlex® HDPE with UV Absorber, Various Antioxidants and Green Pigment . . . . . . . . . . . . . . . . . . Elongation Retained after Xenon Arc Weatherometer Exposure of Ethylene-Vinyl Acetate Polyethylene Copolymer Greenhouse Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conversions of EMMAQUA to Real-Time Performance by Geographic Location . . . . . . . Tensile Strength after Florida and Puerto Rico Outdoor Weathering of Polypropylene Containing Various Antioxidant Stabilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after California and Pennsylvania Outdoor Weathering of Glass-Reinforced Polypropylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tensile Strength Retained after Puerto Rico Outdoor Weathering for Polypropylene Containing Antioxidants and UV Stabilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color and Gloss Changes after QUV Accelerated Weathering for Polypropylene Containing Microcal Calcium Carbonate and Pure Calcium Carbonate . . . . . . . . . . . . . . . Material Properties Retained and Surface Erosion after Atlas Weatherometer Accelerated Weathering of Chevron Phillips Ryton® R4 Polyphenylene Sulfide . . . . . . . . Photo-Oxidation of Polystyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xxvii

169 169 170

171 174 185 186 189 190 190 198 199 200 201 202 203 204 214 216 217 218 219 220 225 227

xxviii 45-2 46-1 46-2 46-3 47-1 49-1 51-1 51-2 51-3 51-4 51-5 53-1 55-1 56-1 56-2 56-3 59-1 59-2 59-3 62-1 62-2 62-3 62-4 62-5 62-6 62-7 62-8 62-9

The Effects of UV Light and Weather on Plastics and Elastomers Mechanical Properties Retained after California and Pennsylvania Outdoor Weathering of Glass-Reinforced General Purpose Polystyrene . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after 18 Months of Florida Outdoor Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after 18 Months of Florida Outdoor Exposure and 3000 hours of Accelerated Weathering for NOVA Chemicals Styrosun® HIPS and Other Materials . . . . Impact Retention after 3000 hours of Accelerated Weathering for NOVA Chemicals Styrosun® HIPS and Other Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained after Outdoor Weathering of Glass-Reinforced Polysulfone in California and Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface and Appearance Properties after Arizona Outdoor Weathering of Dow Tyril® SAN Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exposure Results of Various Plasticized Films with Varying Thicknesses . . . . . . . . . . . . . Outdoor Life of DOP-Plasticized 4 mil (100 µm) Thick Films With Varied Plasticizer Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct Weathering of Select Plasticizers in PVC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Underglass Weathering of Select Plasticizers in PVC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium Dioxide in Films of Three Thicknesses Exposed in Florida . . . . . . . . . . . . . . . . . . Color Change after Accelerated QUV Weathering of Novatec Novaloy® 9000 ABS/PVC Alloy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Color Change, E, after HPUV and Xenon Arc Accelerated Indoor Exposure of Dow Chemical Pulse 1745 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Degradation of Various Mulching Films after Exposure to Natural Solar Radiation at Different Periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Days From Mulching to Appearance of Fracture in Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Degradation of Mulching Films Incorporated with Different Starch Content . . . . . . . . . . . . Surface and Appearance Changes after Xenon Arc Accelerated Weathering Exposure (GM Specifications) of Recticel Colo-Fast® Polyurethane RIM System . . . . . . . . . . . . . . . Surface and Appearance Changes after Xenon Arc Accelerated Weathering Exposure (Japanese Specifications) of Recticel Colo-Fast® Polyurethane RIM System . . . . . . . . . . Surface and Appearance Changes after Fadeometer Accelerated Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System . . . . . . . . . . . . . . . . . . . . . . . . Retention of Mechanical Properties after Xenon Arc Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after Arizona Outdoor Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after Arizona Outdoor Exposure with Spray for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after Florida Outdoor Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after Florida Outdoor Exposure with Spray for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after EMMA Accelerated Exposure with Spray for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after EMMAQUA Accelerated Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after Xenon Arc Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Material Properties after Xenon Arc SAE J1960 Exterior Automotive Testing for Advanced Elastomer Systems Santoprene™ TPV High-Flow Grades . . . . . . . . . . . . . . . . .

228 232 232 233 239 244 250 250 251 251 252 258 261 264 265 265 274 275 276 285 286 287 288 289 290 291 292 293

List of Graphs and Tables 62-10 Material Properties after UV-CON Accelerated Indoor Exposure of PolyOne Forprene® Olefinic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-11 UV Resistance after Accelerated UV Light Exposure of PolyOne Forprene® Olefinic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-12 Ozone Resistance of PolyOne Forprene® Olefinic Thermoplastic Elastomer . . . . . . . . . . 62-13 Ozone Resistance of Advanced Elastomer Systems Santoprene™ Olefinic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-14 Ozone Resistance of Dow Chemical Company’s Engage™ Olefinic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-15 Ozone Resistance of Advanced Elastomer Systems Santoprene™ Black Olefinic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-1 Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for DuPont Hytrel® Polyester Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . 63-2 Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for DuPont Hytrel® 40D Polyester Thermoplastic Elastomer with Carbon Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-3 Material Properties Retained after Florida Outdoor Weathering for DuPont Hytrel® 5556 Polyester Thermoplastic Elastomer with Carbon Black . . . . . . . . . . . . . . . . . . . . . . . . 63-4 Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for Varying Thicknesses of DuPont Hytrel® 6345 Polyester Thermoplastic Elastomer Films with Carbon Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-5 Material Properties Retained after Carbon Arc Accelerated Weathering for DuPont Hytrel® 40D Polyester Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-6 Material Properties Retained after Carbon Arc Accelerated Weathering for DuPont Hytrel® 5556 Polyester Thermoplastic Elastomer with Varying Levels of Carbon Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-7 Material Properties Retained and Surface and Appearance after Carbon Arc Accelerated Weathering for DuPont Hytrel® HT-X-3803 and 4056 Polyester Thermoplastic Elastomer with Varying Levels of Carbon Black . . . . . . . . . . . . . . . . . . . . . . 63-8 Soil Burial and Fungus Resistance for DuPont Hytrel® Polyester Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65-1 Ozone Resistance of Kraton® Styrenic Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . 66-1 Properties Retained after Fadeometer Accelerated Weathering for Noveon Estane® 58202 and Estane® 58300 Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . 66-2 Properties Retained after Fadeometer and QUV Accelerated Weathering for Noveon Estane® 58315 Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66-3 Properties Retained after Fadeometer Accelerated Weathering for Noveon Estane® 58315 and Estane® 58863 Urethane Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . 67-1 Material Properties after Florida Outdoor Weathering of Eliokem Chemigum® Nitrile Thermoplastic Elastomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68-1 Comparison of Ozone Resistance and Weather Resistance for a Few Thermoset Elastomers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-1 Color Pigments Recommended for Use in Hypalon® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-2 Material Properties Retained and Color Change after Outdoor Weathering and Accelerated Weathering of DuPont Elastomers Hypalon® Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-3 Material Properties Retained and Color Change after Arizona Outdoor Weathering for DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . .

xxix

294 295 295 296 297 298 302

303 304

305 306

307

308 309 314 317 318 319 324 326 330

332 333

xxx

The Effects of UV Light and Weather on Plastics and Elastomers

70-4

Material Properties Retained and Color Change after Florida and Delaware Outdoor Weathering for Wire Cable Compound DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-5 Surface and Appearance and Mildew Resistance after Texas and California Outdoor Weathering for Green Hose Cover Compound DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-6 Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for White DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-7 Material Properties Retained and Surface and Appearance after Delaware Outdoor Weathering for DuPont Elastomers Hypalon® 20 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-8 Material Properties Retained and Surface and Appearance after Panama Outdoor Weathering for Pond Liner Formulation DuPont Elastomers Hypalon® 45 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-9 Material Properties Retained and Color Change after EMMA and EMMAQUA Accelerated Outdoor Weathering for Black DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-10 Material Properties Retained and Color Change after Xenon Arc Weatherometer Exposure for Black DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-1 Mechanical Properties Retained after Outdoor and Accelerated Outdoor Weathering of White, Randomly Selected, Unstrained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . 72-2 Mechanical Properties Retained after Outdoor and Accelerated Outdoor Weathering of Black, Weather Resistant, Unstrained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . 72-3 Mechanical Properties Retained after Outdoor and Accelerated Outdoor Weathering of Black, Randomly Selected, Unstrained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . 72-4 Mechanical Properties Retained and Color Change after Outdoor Weathering, Accelerated Outdoor Weathering by EMMAQUA, and Accelerated Weathering with a Xenon Arc Weatherometer for Black Exxon Vistalon EPDM Terpolymer . . . . . . . . . . . . . . 72-5 Material Properties Retained and Color Change after Arizona Outdoor Weathering With and Without Water Spray Added for Black Exxon Vistalon 5600 EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-6 Mechanical Properties Retained and Color Change after Arizona Outdoor Weathering of Black Exxon Vistalon 5600 EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-7 Material Properties Retained after Florida Outdoor Weathering and Accelerated Outdoor Weathering by EMMA for Black, Weather Resistant, Strained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-8 Material Properties Retained and Color Change after Florida Outdoor Weathering With and Without Water Spray Added for Black Exxon Vistalon 5600 EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-9 Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering of Weatherable EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-10 Mechanical Properties Retained after Florida Outdoor Weathering and Accelerated Outdoor Weathering by EMMA for Black, Randomly Selected, Strained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-11 Mechanical Properties Retained after Florida Outdoor Weathering and Accelerated Outdoor Weathering by EMMA for White, Randomly Selected, Strained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

334

335

336

337

338

339

340 349 350 351

352

353 354

355

356 357

358

359

List of Graphs and Tables 72-12 Material Properties Retained and Color Change after Florida Outdoor Weathering of Black EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-13 Material Properties Retained and Color Change after Accelerated Outdoor Weathering by EMMA and EMMAQUA and Accelerated Weathering in a Xenon Arc Weatherometer for Black Exxon Vistalon 5600 EPDM Terpolymer . . . . . . . . . . . . . . . . . . . 72-14 Mechanical Properties Retained and Color Change after Arizona Accelerated Outdoor Weathering by EMMA and EMMAQUA for Black Exxon Vistalon 5600 EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-15 Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for White, Randomly Selected, Strained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-16 Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for White, Randomly Selected, Unstrained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-17 Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for Black, Weather Resistant, Strained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-18 Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for Black, Randomly Selected, Unstrained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-19 Mechanical Properties Retained and Color Change after Accelerated Weathering in a Xenon Arc Weatherometer of Black Exxon Vistalon 5600 EPDM Terpolymer . . . . . . . . 72-20 Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for Black, Weather Resistant, Unstrained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-21 Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer of Black, Randomly Selected, Strained EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-22 Surface and Appearance and Ozone Resistance of Exxon Vistalon EPDM Terpolymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-23 Surface and Appearance and Ozone Resistance of EPDM Terpolymer . . . . . . . . . . . . . . . 73-1 Mechanical Properties Retained and Color Change after Arizona Outdoor Weathering and Accelerated Outdoor weathering by EMMAQUA and Xenon Arc Accelerated Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . . . . . . . . 73-2 Material Properties Retained, Hardness Change, and Color Change after Arizona and Florida Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . 73-3 Mechanical Properties Retained and Color Change after Arizona Outdoor Weathering and Arizona Outdoor Weathering with Spray for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73-4 Material Properties Retained, Hardness Change, and Color Change after Arizona Outdoor Weathering and Arizona Outdoor Weathering with Spray for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73-5 Material Properties Retained, Hardness Change, and Color Change after Florida Outdoor Weathering and Florida Outdoor Weathering with Spray for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73-6 Material Properties Retained, Hardness Change, and Color Change after Xenon Arc Accelerated Weathering and EMMA and EMMAQUA Accelerated Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xxxi

360

361

362

363

364

365

366 367

368

369 370 371

374 375

376

377

378

379

xxxii 73-7

73-8 73-9 74-1 75-1 75-2 75-3 75-4 76-1 77-1 77-2 A2-1

The Effects of UV Light and Weather on Plastics and Elastomers Mechanical Properties Retained and Color Change after EMMA and EMMAQUA Arizona Accelerated Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Properties Retained and Color Change after Xenon Arc Accelerated Weathering for Black DuPont Neoprene® W Neoprene Rubber . . . . . . . . . . . . . . . . . . . . . . Ozone Resistance after Exposure of Black DuPont Neoprene® W Neoprene Rubber . . Ozone Resistance of Japanese Synthetic Rubber JSR BR Polybutadiene Rubber . . . . . Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per the Annulus Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per ASTM D1171 Loop Ozone Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per the Static Strip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per the Kinetic Stretch Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gloss Retained after Xenon Arc Accelerated Weatherometer Exposure of Polyurethane Rubber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Change in Mechanical Properties after Florida and Michigan Outdoor Weathering for Dow Corning Silastic® Silicone Rubber as per ASTM D518, Method A . . . . . . . . . . . . . . . Change in Mechanical Properties after Florida and Michigan Outdoor Weathering for Dow Corning Silastic® Silicone Rubber as per ASTM D518, Method B . . . . . . . . . . . . . . . Comparative Properties and Performance Chart—Coil Coating Topcoats . . . . . . . . . . . . .

380 381 382 384 386 387 388 389 392 393 394 399

Introduction How to Use This Book This data bank publication presents the results of weathering exposure for more than seventy-seven families of plastics and elastomers. Each chapter represents a single generic family. Data appears in textual, tabular, and graphical forms. Textual information is useful as it is often the only information available or the only way to provide an expansive discussion of test results. This is especially true in the case of weathering data where many results are qualitative. Tables and graphs provide detailed test results in a clear, concise manner. Careful study of a table or graph will show how variations in material, exposure conditions, and test conditions influence a material’s physical characteristics. Each table or graph is designed to stand alone, be easy to interpret, and provide all relevant and available details of test conditions and results. The information’s source is referenced to provide an opportunity for the user to find additional information. The source information might also help to indicate any bias which might be associated with the data.

Weatherability Weather Defined Webster’s dictionary defines weathering as a “Noun. Action of the elements in altering the color, texture, composition, or form of exposed objects. Weather: to expose to air; to season, dry, pulverize, discolor, etc., by exposure to air.” In essence, weathering is the natural tendency of materials to return—corrode, oxidize, chalk, permeate, delaminate, depolymerize, flex crack, etc.—to their elemental forms. Variations in Natural Weathering Weathering is variable by region, season, year, etc. Exposure to a subtropical climate such as Florida

can easily be twice as severe as exposure in northerly regions. This is due to the increase in UV radiation caused by the higher average sun angle and exceptionally moist climate. On the other hand, Arizona may offer an increased UV radiation degradation, but has a much lower rate of deterioration due to humidity. Seasonal variations such as higher temperature and increased UV radiation (due to higher sun angle in the summer) can cause summer exposure to be two to seven times as severe as winter exposure in the same place. Variations in weather can change from year to year making one year twice as severe as the last. Natural (outdoor), accelerated outdoor, and accelerated machine testing attempt to recreate weathering and its variability, usually under conditions more severe than normally encountered. Testing for Weatherability The primary purpose served by examining data on weathering of materials is to predict any potential changes of both physical properties and appearance of a part made from those materials. Data on the aging behavior of plastics are acquired through accelerated tests and/or actual weather exposure. These tests serve as a means for comparison of materials and can also be exploited to determine the ability of the material to serve its function when formed into parts and used in a particular environment. Comparisons between materials are made by measuring the retention of properties (e.g., impact strength, gloss, tensile strength, yellowness index) significant to the application as a function of exposure time. The demand for new products has shortened the time available for determining the durability of a particular material. Therefore, accelerated weathering is increasingly used in an attempt to predict the long-term environmental effects in less time than the real-time working life expectancy. Natural sunlight is not standard; there are variations in clouds, smog, angle of the sun, rain, industrial environments, etc. Likewise options and

2

The Effects of UV Light and Weather on Plastics and Elastomers

approaches to the testing of plastic materials and their additives vary among individuals and change as theory becomes application. As a result, there are differing opinions as to the validity of testing, both with natural exposure and under accelerated or laboratory conditions. Testing and reliance on test results is necessary in the product development process to determine the durability of materials in particular applications. An accelerated weathering method correlates with real-time exposure testing when specific defects can be generated in a material with an acceptable precision in a repeatable, shorter interval. Many manufacturers and suppliers worldwide find the correlations acceptable and have adopted test specifications for accelerated and artificial weathering. The factors that influence the degree of weathering are: •

Solar radiation (usually UV)

•

Moisture (dew, humidity, rain)

•

Heat (surface temperature of the material)

•

Pollutants (ozone, acid rain)

•

Salt water

Because these factors vary so widely over the earth’s surface, the weathering of materials is not an exact science. It is virtually impossible to rank the degenerative power of temperature, moisture, and UV radiation. Most materials are weathered by a combination of these factors, but some are degenerated by moisture alone or UV radiation alone. Before one can determine the appropriate test procedure for a particular material, it is important to become familiar with the elements of natural weathering, how they work, and how they may work together to cause adverse effects on the durability of a given part.

or reinforcing action, has been demonstrated many times in studies on durability. Radiation UV wavelengths from sunlight are an important component in outdoor degradation. The energy from sunlight is mainly visible light (700–400 nm), infrared (manifested as heat), and UV light (400– 10 nm).∗ Although UV radiation amounts to only 3% of the total radiation that reaches the earth, it is energetic enough to cause chemical reactions, weathering of polymers, and fading of certain dyes. The energy contained in UV light is capable of directly rupturing polymer chains (chain scission), and, in the presence of oxygen, UV radiation causes oxidation of plastics. The wavelengths that cause the most damage to polymers are in the UV range, 290–400 nm. At the shortest wavelengths in the UV region, the photon energy is of the same order of magnitude as the energies of the bonds in common polymers. The intensity of this short-wavelength radiation is strongly dependent on season and location.[1] The infrared (felt as heat) portion of sunlight warms plastics and accelerates the harmful effects of UV light. In the continental United States, weathering conditions are several times more severe in summer than in winter. This is partly due to the increase in the amount of UV light that penetrates the atmosphere and reaches the ground in the summer and partly due to higher temperatures.[2] The solar UV radiation spectrum is divided into three ranges. UV-A is the energy with wavelengths between 400 and 315 nm. UV-B is the spectrum from 315 to 290 nm. UV-C includes solar radiation below 290 nm. The wavelength regions of UV radiation and their characteristics relative to degradation of materials are listed below. Wavelength Regions of UV Radiation

Elements of Weather The process of weathering includes the action of elements in addition to the effects of radiation. The combination of these factors produces an effect greater than the sum of the individual effects; degradation due to radiation is accelerated when the other elements operate at the same time. This synergism,

UV-A 400–315 nm

∗ Nanometers

Always present in sunlight; 400 nm upper limit for UV-A is the boundary between visible light and UV light; energy at 315 nm boundary

(nm) are commonly used for measuring wavelengths. 1 nm = 10−9 m.

3

Introduction begins to cause adverse effects and pigmentation changes in human skin and some polymers. UV-B 315–290 nm

Includes the shortest wavelengths found at the earth’s surface; responsible for severe polymer damage; absorbed by window glass; UV light absorption by ozone varies with solar altitude; 290–315 nm is completely absorbed at altitudes below 14◦ , at 19◦ solar cutoff is 310 nm, at 40◦ solar cutoff is 303 nm, at solar altitudes between 60◦ and 90◦ maximum UV-B reaches the earth’s surface with a solar cutoff at approximately 295 nm.

leaves the material vulnerable. The severity of moisture attack increases dramatically with increasing temperature.

Radiation and Water

UV-B wavelengths cause the most damage to polymeric materials.

Radiation and water, two components of weather, tend to operate at different times. However, materials can be irradiated after having been wet by rain or when they have high moisture content from overnight high humidity. In this situation, radiation can accelerate the effect of water, and vice versa.[3] It is also possible for radiation to raise the temperature of a material to the point where solution or hydrolysis can occur. In the case of plasticizers, vinyl coatings and plastics may delaminate if they are appreciably soluble in water at elevated temperatures. Strength of polyester laminates can also be reduced through attack by water either on the resin itself or on the bond between the resin and the glass fiber. These actions are not so marked as in actual immersion in hot water, but they can contribute to the degradation process.[3]

Moisture

Radiation and Oxygen

A high incidence of moisture has important implications on the durability of a part. It is often the case that water is not destructive in itself, but water causes damage by bringing oxygen into intimate contact with the material and thereby promotes oxidation. Generally, the potential for degeneration from dew exceeds that associated with rain. In Florida, materials are exposed to outdoor wetness an average of eight hours per day, or about 2900 hours of moisture per year. Materials are wet from dew or condensation more frequently and for longer durations than from rain. To condense dew, a material must be cooler than the dew point temperature of air. This usually occurs during night when solid objects lose their heat through radiation. The fact that materials are exposed primarily to dew and not rain affects the type of degradation that will occur. Dew is saturated with oxygen and lies on materials for hours. The resulting internal oxidation and leaching of soluble additives

A natural weathering combination that has probably even greater effect is oxygen and radiation, referred to technically as photo-oxidation. Materials subjected to oxygen are degraded much faster in the presence of radiation than in its absence. For example, discoloration of polystyrene occurs more rapidly when irradiation takes place in air or oxygen. With saturated polymers there is little damage from oxygen at room temperature if UV radiation is absent.[3]

UV-C 290–100 nm

The UV-C range is a sharp cutoff of solar radiation at the earth’s surface due to complete absorption by ozone; found only in outer space.

Reducing the Effect of Radiation Because the effects of heat, oxygen, and radiation can be severe, attempts are made to reduce susceptibility to one or more of the factors. It is difficult to remove the potential exposure to heat and oxygen in an environment, and radiation is often the most important of the three factors. Thus, there are several options other than additives that could reduce exposure of a polymer to radiation.[3]

4

The Effects of UV Light and Weather on Plastics and Elastomers •

A transparent polymer does not absorb radiation, therefore, minimizing the effects of the radiation. In the real world it is difficult to achieve complete transparency as evidenced by polyethylene, which is transparent to UV radiation but readily degrades upon exterior exposure.[3]

•

Manufacture polymers whose bond strengths exceed the energy available in solar radiation. The potential for success of this method is limited by the fact that most such combinations form simple compounds instead of polymerizing. These materials are often readily decomposed by water or oxygen. Silicones are an example of this polymer type with a silicon-oxygen backbone and organic side groups. “The siliconoxygen bond is only broken by radiation of wavelengths below 270 nm, and this is not received at the earth’s surface. The organic groups are necessary for the material to have the properties required of a polymer; without them the material is quartz or silica—SiO2 . Fluorocarbon polymers are another example. Although fluorine is not part of the molecular backbone, the high strength of the fluorine-carbon bonds in the side groups contributes markedly to their excellent exterior durability.”[3]

•

“The final and most common procedure in minimizing the effect of radiation is to prevent the polymer from absorbing it. If the material does not have to be transparent this can readily be accomplished through the incorporation of pigments that reflect radiation or absorb it preferentially. Reflection usually occurs at the pigment surfaces within the resin so that the radiation has to pass through the top layers twice. Some degradation can, therefore, occur at the surface, and this is why materials frequently lose gloss on exposure. For complete absorption to take place the pigment must be black. Incorporation of black pigment is very effective, as shown by the increase in durability

of polyethylene from one year to 20 years with the addition of 1 per cent carbon black. The color, however, is not always acceptable. For other colors titanium, zinc or iron oxides can be used, but higher concentrations are required.”[3] Surface Temperature and Thermal Degradation Surface temperature is the most variable factor in weather. An automobile driven at 55 mph on a highway will attain a surface temperature near ambient. The same car, locked and parked in direct sunlight, can reach a surface temperature 30◦ C above ambient. At night, with no wind and a clear sky, the surface temperature can drop 8◦ C below ambient. Color is also a contributing factor in surface temperature. White materials typically attain a temperature 10◦ C–15◦ C lower than black materials. It is difficult to match outdoor temperature differences between dark and light materials in the laboratory. For example, the introduction of air for heating and cooling will reduce temperature differences between colors. While temperature is an important factor in weathering, it is also important to note that not all materials show increased degradation with increased temperature. Thermal degradation of polymers, molecular deterioration as a result of overheating, can result from exposure to the elements. At high temperatures the components of the long-chain backbone of the polymer begin to separate (molecular scission) and react with one another to change the properties of the polymer. Thermal degradation generally involves changes to the molecular weight (and molecular weight distribution) of the polymer. Significant thermal degradation can occur at temperatures much lower than those at which mechanical failure is likely to occur.[4]

Material Properties Post-Exposure The many concurrent chemical processes taking place in polymers exposed to UV radiation result in several different modes of damage, each progressing at a different rate. It is usually the critical first-observed damage process that determines the

5

Introduction

useful service life of the product. For example, a polyvinyl chloride (PVC) window frame exposed to sunlight undergoes discoloration, chalking, loss of impact strength, and a reduction in tensile properties as well as a host of other chemical changes. It is, however, the discoloration (or the uneven yellowing) of the window frame that generally determines its service life. However, with continued use, other damage such as chalking and eventually loss of impact resistance (leading to cracking) can occur making the product even more unacceptable. The two critical modes of photodamage applicable to most natural and synthetic materials are yellowing discoloration and loss of mechanical integrity.[5] Exposure of many plastics to UV radiation causes a loss in their mechanical properties and/or a change in their appearance. Typical property changes include: •

Reduced ductility and embrittlement

•

Chalking

•

Color changes

•

Yellowing

•

Cracking

Photodegradation causes a loss of strength, impact resistance, and mechanical integrity of plastics exposed to UV radiation. These changes in mechanical properties reflect the result of polymer chain scission (and/or cross-linking). The molecular changes of these materials can be characterized through the study of solution viscosity and the gel permeation characteristics. The embrittlement produced by UV radiation exposure is often evaluated by measuring the impact resistance (toughness) of the material.[5] Deterioration in appearance produced by UV radiation exposure can be evaluated by measuring color shift and gloss. The observed color shift, E, may be affected by the change in gloss. While the determination of gloss is straightforward, techniques for evaluating color shift may vary considerably. A very sensitive method of quantifying the change in the mechanical properties of polymers brought about by the effects of weathering is to determine the penetration energy on weathered specimens. If the unirradiated reverse side of the specimens is impacted, the irradiated front side experiences a sudden tensile stress, so that even the

slightest deterioration gives a clear reduction in the measured values. This test is therefore an excellent indicator of weathering resistance. In contrast, if the impact is on the irradiated side, as most frequently happens in practice, a reduction in toughness is only observed after much longer exposure times. Measurable reductions in the values of properties such as breaking stress and modulus of elasticity are also seen only at a much later stage.[6]

UV Additives and Stabilizers UV sensitivity is based on complex photolytic and photo-oxidative mechanisms that lead to material degradation as a result of chain scission. Reactive radicals are produced by the energy-rich UV light. In the presence of oxygen the plastics are oxidized (photo-oxidation). Two methods of UV stabilization are commonly used: UV absorbers (e.g., benzotriazoles) and UV stabilizers (e.g., hindered amines). Hydroxybenzotriazoles preferentially absorb light in the 300– 400 nm wavelength range. They dissipate the light energy by a tautomeric process, which protects the polymer by preventing it from absorbing harmful radiation. Hindered amines, on the other hand, act as radical scavengers. Through the formation of nitroxyl radicals, hindered amines terminate and deactivate alkyl radicals and peroxy radicals, which are known to participate in the photo-oxidation process. While functioning as radical scavengers, the stabilizing species (the nitroxyl radical) is regenerated and continues to scavenge.[7] Effective light absorbers such as benzotriazoles, benzophenones, and phenyl esters as well as hindered amine light stabilizers (HALS) are presently used in plastics formulations intended for outdoor use (usually at a 0.05–2.0 wt% level). Improved stabilizers are introduced into the market periodically.[5] In conventional light stabilization by pigments such as carbon black and titanium dioxide, the UV radiation is absorbed by the pigments and chain scission of the polymer is prevented. The soluble light stabilization systems are combinations of UV absorbers and radical interceptors. UV absorbers convert UV light into harmless thermal energy. Radical interceptors or HALS react with spontaneously forming radicals to form harmless derivatives.

6

The Effects of UV Light and Weather on Plastics and Elastomers

UV Absorbers UV absorbers or stabilizers are most efficient when used in materials that have a thick cross section because the amount required is a function of concentration and thickness. Thus, a plastic 20 mils (0.5 mm) thick might be stabilized with 0.5% absorber but requires 1% at 10 mils (0.25 mm) and 2% at 5 mils (0.125 mm). This relation is not strictly linear; effectiveness is reduced at higher concentrations so that more is required than calculated from the relationship.[6] UV absorbers can be rather specific in their action—even absorbers that are closely related chemically may show large differences in effectiveness with different resins. As a result, comprehensive tests are needed to determine the type and amount of absorber to be used with any given polymer. It must also be appreciated that absorbers do not last indefinitely, but are slowly degraded, and that the absorption they are intended to prevent will ultimately occur.[6]

Hindered Amine Light Stabilizers With organic light stabilizers such as hindered amines, increasing the stabilizer level in the

composition will have little or no impact on processibility of the resin. The cost, however, will be significantly affected because the contribution of the stabilizer cost to the total cost of a product such as greenhouse films can be as much as 30%.

Antioxidants Antioxidants are also commonly used to aid in UV stabilization. Although antioxidants are neither light stabilizers nor UV absorbers, they often improve the overall weatherability of the polymer when used in combination with a UV absorber or light stabilizer. They do this by interrupting the free-radical process during photo-oxidation.[7]

UV Inhibitors UV inhibitors, commonly referred to as UVIs, are chemical compounds that absorb UV light and disperse the energy contained in UV radiation in a form that is less harmful to the plastic. Most materials synthesized for the purpose of being used as UVIs are transparent and essentially colorless, but there are also some pigments and dyes that function as UVIs.[2]

Test Environments Indoor and Interior Exposure During indoor exposure, products are subjected to UV radiation from fluorescent lights as well as from glass-filtered UV rays transmitted through windows. The type of light source, its energy flux, and its distance from the specimens determine the intensity of the radiation impinging on the surface of the part. Glass of any type acts as a filter on the sunlight spectrum. The shorter, most damaging wavelengths are the most greatly affected. Ordinary window glass is essentially transparent to light above 370 nm. However, the filtering effect becomes more pronounced with decreasing wavelength. Windshield glass is thicker than window glass; it acts as a more efficient filter. Safety features associated with windshield glass (e.g., tinting and plastic) add to the filtering efficiency. Almost all UV light is filtered out

by windshield glass, and the most damaging wavelengths below 310 nm are completely filtered out.

Outdoor Testing Real-time weathering data from natural environment exposure programs remain the standard to which all other weathering data are compared. Three of the most commonly used harsh aging sites are Arizona, Florida, and Japan. Arizona is important because of its high annual radiation and ambient temperature. Southern Florida is unique because of its high radiation combined with high rainfall and humidity. These two areas have become US and international reference climates for gauging the durability of materials since they represent the worst case for applications in the northern hemisphere.

8

The Effects of UV Light and Weather on Plastics and Elastomers

With all outdoor tests it is important to be aware of bias introduced by the choice of location. Details about a few representative test sites are listed in the chart above. In Miami, Florida, there are approximately 110 sun hours per month. This is a total of 1200–1300 sun hours per year. With a 45◦ due south exposure, test specimens receive approximately 150,000 langleys per year.

Accelerated Outdoor Tests In outdoor tests, the usual standard procedure calls for specimen exposure on racks facing due south at an angle of 45◦ . These are conditions that offer a maximum direct sunlight exposure and intensity. This tilt is also preferable since it allows for some drainage and wash off during rains. Sources of radiation for outdoor exposure tests include both direct and reflected sunlight. In a further attempt to accelerate outdoor effects, many studies are conducted in tropical as well as hot, dry climates such as Florida and Arizona in the United States, and Panama, Germany, and Japan to obtain the most wide ranging and severe environments possible. Outdoor accelerated weathering is a relatively recent technique. It relies heavily on technology to follow the track of the sun and to keep the sample at a constant temperature. Equatorial Mount with Mirrors for Acceleration (EMMA): Natural sunlight and special reflecting mirrors are used to concentrate sunlight to the intensity of about eight suns. The test apparatus follows the sun track with mirrors positioned as tangents to an imaginary parabolic trough. The axis is oriented in a north–south direction, with the north elevation having the capability for periodic altitude adjustments. A blower directs air over and under the samples to cool the specimens. This limits the increase in surface temperatures of most materials to 10◦ C (50◦ F) above the maximum service temperature that is reached by identically mounted samples exposed to direct sunlight at the same times and locations without concentration. Exposed periods of 6 and 12 months have been correlated to about 2.5 and 5 years of actual aging in a Florida environment, respectively.

Equatorial Mount with Mirrors for Acceleration Plus Water (EMMAQUA): Natural sunlight and special reflecting mirrors are used to concentrate sunlight to the intensity of about eight suns. In addition to intensifying the power of the sun, a water spray is used to induce moisture weathering conditions. The test apparatus follows the sun track with mirrors positioned as tangents to an imaginary parabolic trough. The axis is oriented in a north– south direction, with the north elevation having the capability for periodic altitude adjustments.Ablower directs air over and under the samples to cool the specimens. This limits the increase in surface temperatures of most materials to 10◦ C (50◦ F) above the maximum service temperature that is reached by identically mounted samples exposed to direct sunlight at the same times and locations without concentration. Exposure to EMMAQUAis considered to be the harshest exposure.

Conventional Aging This test method, which may occur in many different geographic locations (e.g., Florida, Arizona, and Okinawa, Japan), is real-time exposure at a 45◦ tilt from the horizontal. Direct exposures are intended for materials that will be used outdoors and subjected to all elements of weather. Exposure times are generally 6, 12, 24, and 48 months. Location is an important factor in the harshness of this test. The assumption is that test results from a hostile environment will prevail in more moderate conditions. Conventional Aging with Spray This test method, which may occur in many different geographic locations (e.g., Florida, Arizona, and Okinawa, Japan), is real-time exposure at a 45◦ tilt from the horizontal with a water spray used to induce moisture weathering conditions. The introduction of moisture plays an important role in improving both the relevance and reproducibility of the weathering test results. The purpose of wetting is twofold. First, the introduction of water in an otherwise arid climate induces and accelerates some degradation modes that do not occur as rapidly, if at all, without moisture. Second, a thermal shock causes a reduction in specimen surface

9

Test Environments temperatures, as much as 14◦ C (57◦ F). This results in physical stresses that accelerate the degradation process. Spray nozzles are mounted above the face of the rack at points distributed to ensure uniform wetting of the entire exposed area. Distilled water is sprayed for four hours preceding sunrise to soak the samples, and then twenty times during the day in 15-second bursts. Direct exposures are intended for materials that will be used outdoors and subjected to all elements of weather. Exposure times are generally 6, 12, 24, and 48 months. Location is an important factor in the harshness of this test. With all outdoor tests it is important to be aware of bias introduced by the choice of location. Humidity Variations Atmospheric humidity is very high in Florida, very low in Arizona, and variable in Tennessee. Results obtained at these stations should be indicative of performance to be expected under comparable conditions of latitude, elevation, temperature, and humidity throughout the world.[2] Solar Radiation Weathering conditions are more severe in Arizona and Florida than in Tennessee, and generally more severe in Arizona than in Florida. Solar radiation in Phoenix averages more than 185,000 langleys per year on a horizontal surface; the average daytime high temperature exceeds 38◦ C (100◦ F) during the summer months.[2]

Sample Mounting Direction Experimental weathering is done in an open location with the samples facing south and inclined northward at an angle of 45◦ from the vertical, exposing the specimens to almost the maximum possible sunshine with a fixed mounting in the central northern latitudes. (This mounting is specified in Test Method D1435 published by the American Society for Testing and Materials.) Less severe exposure would increase the life expectancy of the material over that indicated by the test results. For example, a meter cover mounted on the east wall of a house might receive less than half the available sunshine, and its useful life should be substantially longer than that of a test specimen. Differences in weathering due to different mounting directions are accentuated by the fact that the rays of the midday sun contain much more energy than the early morning and late afternoon rays.[2]

Artificial Accelerated Tests Artificial weathering devices, tests that use artificial light sources, are used to measure the resistance of materials to weather degradation. These tests provide reliable data in a shorter period of time than outdoor testing. Light sources for the accelerated tests include filtered long arc xenon, fluorescent metal halide lamps, and carbon arc. Less commonly used light sources include mercury vapor and tungsten lamps. Each light source has its own inherent benefits of which a weathering experimenter must be aware.

Conditions for Reproducing Natural Weathering Stresses in the Laboratory UV Conditions UV-B emission with minimal emission below 290 nm

Water Conditions Condensed from vapor phase; pH approximately 4.0–6.0; saturated with O2

Exposure Duration

No theoretical maximum or minimum; practical minimum of three to four hours

Time and temperature interact; practical limits of four to twenty hours

Temperature

55◦ C–80◦ C as required to duplicate service temperature

60◦ C sometimes causes abnormal effects; 50◦ C for eight hours can cause problems; 40◦ C is safe but slower

Quality

10

The Effects of UV Light and Weather on Plastics and Elastomers

Xenon Arc Xenon arc is a precision gas discharge lamp sealed in a quartz tube. Through a combination of filters used to reduce unwanted radiation, the xenon (long) arc simulates UV and visible solar radiation more closely than any other artificial light source. It is widely preferred as a light source when the material to be tested will be exposed to natural sunlight.[8] Automotive test SAE J1885 is used for testing interior automotive materials and calls for xenon arc exposure with quartz inner and borosilicate outer filters. This filter combination transmits short-wave UV radiation as low as 275 nm. Automotive test SAE J1960 is used to evaluate exterior automotive materials by accelerated means. The test uses a quartz/borosilicate-S filter combination. Most engineers involved with this test state that 2500 kJ/m2 is approximately two years of Florida testing. However, the spectral power distribution (light intensity vs. wavelength) of the SAE J1960 test method does not exactly match actual Miami sunlight and can be a nonpredictive test for some materials. Some automotive companies use different optical filter combinations (Boro-S/Boro-S or CIRA/Soda Lime) that more closely match true Miami solar radiation. In addition, the comparison based on a single factor (solar radiant energy) does not take into account the other weathering factors such as heat, moisture, etc., and their synergistic effects, which magnify the effects of solar radiation.[8] Test methods specifying xenon arc include ASTM D2565, D4459, and G155, SAE J1885 and SAE J1960, and GE Co. Highly Accelerated Weathering Protocol for all outdoor applications.

Fluorescent or QUV The QUV test procedure simulates long-term outdoor exposure to sunlight, rain, and dew by exposing materials to alternating cycles of UV-A or UV-B light and moisture at controlled elevated temperatures. These are the most aggressive components of weathering—UV radiation, moisture, and heat. UV radiation within a desired UV wavelength is provided through the use of fluorescent lamps.

Moisture is provided by forced condensation and temperature is controlled by heaters.[9] Although UV light makes up only about 5% of sunlight, it is responsible for most of the damage caused to durable materials exposed outdoors. To simulate the damage caused by UV rays, it is not necessary to reproduce the entire spectrum of sunlight. In many cases it is only necessary to simulate the short-wavelength UV. Each type of lamp differs in the total amount of UV energy emitted and in its spectrum. Fluorescent UV lamps are usually categorized as UV-A or UV-B lamps, depending on the region into which most of their output falls.[10] UV-A lamps are useful for comparing different types of polymers. Because UV-A lamps do not have any UV output below 295 nm, they do not degrade materials as quickly as UV-B lamps. UV-A lamps usually provide good correlation with actual outdoor weathering.[10] UVA-340 lamps provide the best possible simulation of sunlight in the critical short wavelength from 365 nm down to the solar cutoff of 295 nm. It is most useful in comparison tests of different formulations.[10] UVA-351 lamps simulate the UV portion of sunlight filtered through window glass. It is most useful for simulating interior applications.[10] UV-B lamps are used for fast, cost-effective testing of durable materials. All UV-B lamps emit shortwavelength UV below the solar cutoff of 295 nm. Although this short-wave UV accelerates testing, it can sometimes lead to anomalous results.[10] UVB-313 is the most widely used UV-B lamp for testing very durable applications. It is especially useful to maximize acceleration when testing very durable applications like automotive coatings and roofing materials.[10] QFS-40 is the original QUV lamp. These lamps are also known as FS-40 or FS-40 UVB. It has demonstrated good correlation to outdoor exposures for gloss retention on automotive coatings and for material integrity of plastics.[10] Tests using fluorescent lamps are useful for relative rank comparisons between materials under specific conditions, but the comparison to service lifetime performance or correlation to outdoor exposures may not be valid. The best use of the UV lamps is for general screening tests such as checking for

11

Test Environments

gross formulation errors with an artificially harsh exposure.[8] Test methods specifying the QUV UV-340 lamp include ASTM D4329 and D4587, ISO 4892, and SAE J2020. Carbon Arc or Fadeometer Carbon arc devices generally use two lamps (twin arc). The flame carbon arc is open or enclosed (ECA), encased in a borosilicate glass cover that acts as a filter for low-wavelength radiation. The spectral emission of the flame carbon arc, a significant amount of which is below 300 nm, bears little resemblance to sunlight. The two strong emission bands of an enclosed carbon arc peak at 358 and 386 nm and are much more intense than natural sunlight. Therefore, carbon arc testing will have a weaker (than actual outdoor) effect on materials that absorb only short-wavelength radiation. In addition, ECA results will have a stronger (than actual outdoor) effect on materials that absorb long-wavelength UV and visible light.[8] Sunshine Carbon Arc provides a better match to natural sunlight than ECA at longer wavelengths. However, Sunshine Carbon Arc provides more radiation at wavelengths below 300 nm than natural sunlight.[8] Due to the fact that some materials absorb primarily short wavelengths and some materials absorb primarily longer wavelengths, carbon arc light sources can distort the relative light stability of tested materials, especially when compared to samples exposed to actual solar radiation.[8] “While good correlation with outdoor exposures has been reported for some materials whose weathering mechanisms are appropriate for these limited spectrum sources, this technology has largely been replaced with fluorescent UV or xenon arc systems.” Carbon arc testing continues to be used to test material durability in some applications.[8]

Test Results Failures of exposed specimens are measured or recorded in several different ways including:[11] •

Time-To-Fifth Spot: Clear films show incipient failure by development of

very small random brown spots characteristic of UV degradation. The “first failure” is recorded as the time to the fifth spot on these clippings. The first few spots may appear fortuitous in some cases and unrelated to general failure. •

Final Failure: Spotting and accompanying embrittlement continue until the film loses integrity and tends to tear from the rack or until it is completely brown. This is the “final failure” time.

•

Brittleness Temperature: The brittleness temperature is measured before exposure and then on the samples as they are received at regular intervals from the exposure site. Measurements are run up to 22◦ C. The ASTM 179062 (Masland Cold Crack) method, with the use of semi-micro specimens, is followed in determining brittleness temperatures.

•

Elongation: Elongation is measured on the samples before exposure. As the samples are received from the testing site, their elongations are again measured.

Notes on Variability in Testing and Results Similar test methods can yield test results that vary widely. When comparing results, the user should take into consideration that factors such as test sites, time of year, pollution counts, and sample conditioning, to name a few, can have a huge impact on test results. For instance, at Florida test sites, results can vary widely due to an increase in wetness caused by proximity to a pond or other sources of moisture or dew, or by proximity to woods that shield the drying effects of wind. Another example is variation in sample mounting and its effect on the period of degradation. Plywood backed samples, for instance, get much hotter in direct sunlight than unbacked samples and they are wet for up to twice as long. The “synergistic” effect of UV radiation with moisture is an important area in assessing the validity

12

The Effects of UV Light and Weather on Plastics and Elastomers

of accelerated testing and its correlation to the natural weathering process. Much of the weathering literature focuses on the interaction between morning dew and UV radiation. While it is clear that this effect can be reproduced in a laboratory situation, it is not clear that it occurs under actual exposure conditions. The situation is reproduced with devices such as UV-CON and EMMAQUA. However, under normal outdoor exposure, sunlight will probably dry materials before the sun elevation reaches a point where UV-B is transmitted through the atmosphere. Laboratory conditions must be closely matched to actual weathering situations and it is recommended that you carefully consider your own situation in comparing it to the test conditions and data presented in this book.

Color Stability UV light stability of pre-colored resins is often not the same for clear or natural resins. Color stability

depends on many factors, so actual performance will depend on lighting conditions, length of time exposed per day, proximity of material to light sources and windows, choice of color pigments, and other factors. In general, there are two approaches to light stabilization. In the conventional method, light stabilization is achieved with pigments such as carbon black and titanium dioxide. If special requirements are imposed on the material or if a special color is required, then additional light stabilizers and additives are required. When inorganic opacifiers such as titania or carbon black are used with resins such as PVC, for instance, higher levels will affect processibility, power consumption, and even the lifetime of processing equipment, due to increased melt viscosity.[5]

Chapter 1

Acrylonitrile-Butadiene-Styrene Category: Engineering resin. General Description: Acrylonitrile-butadienestyrene (ABS) is a thermoplastic styrene copolymer produced from acrylonitrile, butadiene, and styrene. •

BASF Terluran® is a two-phase polymer blend ABS. A continuous phase of styrene-acrylonitrile (SAN) copolymer gives the materials rigidity, hardness, and heat resistance.[4]

Weathering Properties When ABS is used for extended periods of time in outdoor locations or under fluorescent light, discoloration or distinctive degradation of properties will occur. The cause of weathering-related ABS problems is light-induced degradation of polybutadiene, and as a result of this, the contribution of the rubber to improved impact strength is diminished. This type of degradation is restricted to surface layers.[12] Prolonged exposure to the weather, especially direct sunlight, will cause significant changes in both the appearance and the mechanical properties of ABS plastics. Terluran® is stabilized to inhibit aging caused by atmospheric oxygen and elevated temperature. This stabilization allows Terluran® parts many

years of service life in indoor applications and even in interior automotive applications where the parts are subjected to considerable UV exposure.[4] Sunlight and atmospheric oxygen will damage the butadiene-containing elastomer component of ABS during long-term exposure resulting in yellowing and reduced impact strength. Although this process can be delayed by the use of dark colors or by stabilization, the preferred material for most outdoor applications is BASF Luran® S, an acrylonitrilestyrene-acrylate (ASA) material, which considerably outperforms ABS in weathering resistance.[4] The effect of exposure to UV radiation on the impact strength of ASA and ABS were compared. Standard specimens were exposed on one side in the Xenotest 1200 and tested per DIN 53453 impact test with a blow struck on the unexposed side. The ABS specimens suffered a very rapid drop in impact strength. The ASA specimen retained its impact strength under these conditions over a longer period of time, about seven times as long.[13]

Stabilization Because of its butadiene component, ABS requires UV stabilizers. Synergistic combinations of benzotriazoles (UV absorbers) and hindered amine light stabilizers (HALS) provide improved light stability.[14]

14

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 1-1. Outdoor Weathering of White ABS in Florida

Table 1-2. Outdoor Weathering of ABS in Ludwigshafen, Germany

1: Acrylonitrile-Butadiene-Styrene Table 1-3. Accelerated Indoor Exposure of GE Plastics Cycolac® VW300 ABS by HPUV

Table 1-4. Accelerated Indoor Exposure of GE Plastics Cycolac® KJB ABS to Fluorescent Light

15

16

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-1. Changes in Material Characteristics due to Photo-Oxidation of ABS.[12] 120

Deterioration (%)

100

80 Luster 60

Impact strength Tensile strength

40

20

0 0

1

2

3

4

5

6

Outdoor Weathering (years) Note: The depth of the degraded layer brought about by weathering is of the order of several hundred micrometers. The reaction to photo-oxidation results in the generation of a thin yellow layer at the surface; this layer prevents the diffusion and permeation of oxygen and, in addition, it blocks out light. Accordingly, any further photo-oxidation at the interior of the component is prevented.

Graph 1-2. Outdoor Weathering Exposure Time vs. Yellowness Index of ABS.

1: Acrylonitrile-Butadiene-Styrene

Graph 1-3. Arizona Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS.

Graph 1-4. Arizona Outdoor Weathering Exposure Time vs. Elongation of ABS.

17

18

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-5. Arizona Outdoor Weathering Exposure Time vs. Tensile Strength at Yield of ABS.

Graph 1-6. Arizona Outdoor Weathering Exposure Time vs. E Color Change of ABS.

1: Acrylonitrile-Butadiene-Styrene

19

Graph 1-7. Arizona, Florida, and Ohio Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS.

Graph 1-8. Florida Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS.

20

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-9. Florida Outdoor Weathering Exposure Time vs. Drop Weight Impact of ABS.

Graph 1-10. Florida Outdoor Weathering Exposure Time vs. E Color Change of ABS.

1: Acrylonitrile-Butadiene-Styrene

21

Graph 1-11. Florida Weathering Exposure Time vs. Chip Impact Strength of ABS (White Rovel Capstock and Acrylic Capstock).

Graph 1-12. Florida Weathering Exposure Time vs. Chip Impact Strength of ABS (Natural Resin).

22

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-13. Ohio Outdoor Weathering Exposure Time vs. E Color Change of ABS.

Graph 1-14. Ohio Outdoor Weathering Exposure Time vs. Dart Drop Impact Strength of ABS.

1: Acrylonitrile-Butadiene-Styrene

23

Graph 1-15. Okinawa, Japan, Outdoor Weathering Exposure Time vs. E Color Change of ABS.

Graph 1-16. Okinawa, Japan, Outdoor Weathering Exposure Time vs. Dynstat Impact Strength Retained of ABS.

24

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-17. Okinawa, Japan, Outdoor Weathering Exposure Time vs. Elongation at Break Retained of ABS.

Graph 1-18. Okinawa, Japan, Outdoor Weathering Exposure Time vs. Gloss Retained of ABS.

1: Acrylonitrile-Butadiene-Styrene

25

Graph 1-19. West Virginia Outdoor Weathering Exposure Time vs. Falling Dart Impact of ABS at −40◦ C.

Graph 1-20. West Virginia Outdoor Weathering Exposure Time vs. Falling Dart Impact of ABS at 23◦ C, −25◦ C, and −40◦ C.

26

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-21. West Virginia Outdoor Weathering Exposure Time vs. Falling Dart Impact of ABS at 23◦ C.

Graph 1-22. West Virginia Outdoor Weathering Exposure Time vs. Flexural Modulus Retained of ABS.

1: Acrylonitrile-Butadiene-Styrene

27

Graph 1-23. West Virginia Outdoor Weathering Exposure Time vs. Flexural Strength of ABS at −40◦ C and 23◦ C.

Graph 1-24. West Virginia Outdoor Weathering Exposure Time vs. Flexural Strength Retained of ABS.

28

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-25. West Virginia Outdoor Weathering Exposure Time vs. Izod Impact Strength Retained of ABS.

Graph 1-26. West Virginia Outdoor Weathering Exposure Time vs. Tensile Strength Retained of ABS.

1: Acrylonitrile-Butadiene-Styrene

Graph 1-27. Sunshine Weatherometer Exposure Time vs. Dynstat Impact Strength Retained of ABS.

Graph 1-28. Sunshine Weatherometer Exposure Time vs. Elongation at Break Retained of ABS.

29

30

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-29. Sunshine Weatherometer Exposure Time vs. Gloss Retained of ABS.

Graph 1-30. Weatherometer Exposure Time vs. Impact Strength of ABS.

1: Acrylonitrile-Butadiene-Styrene

Graph 1-31. Xenotest 1200 Exposure Time vs. Impact Strength of ABS.

Graph 1-32. Accelerated Indoor UV Exposure Time vs. E Color Change of ABS.

31

32

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 1-33. Yellowness Index of UVA- and HALS-Stabilized ABS after Outdoor Weathering in Switzerland.[14] 25

Control

Yellowness Index

20

15 0.25% UVA 0.25% HALS 10 0.5% UVA 0.5% HALS 5

0 0

40

80

Exposure Time (kilolangley)

120

Chapter 2

Acrylonitrile-Styrene-Acrylate/ Acrylonitrile-Butadiene-Styrene Capstock General Description: GE Plastics’ co-extrusion of Cycolac® acrylonitrile-styrene-acrylate (ASA) and Geloy® acrylonitrile-butadiene-styrene (ABS) resins allows designers, molders, and manufacturers to take advantage of the best properties of both materials in a single product.[25]

Weathering Properties The multilayering technology allows the weather resistant material to be used as capstock. Capstock is the material used as the additional surface layer applied to the exterior surface of a profile extrusion. Geloy® resin capstock over a Cycolac® substrate provides outstanding weatherability.[25]

Weathering Properties by Material Supplier Trade Name Graph 2-1. Color Change, E, after Arizona, Florida, and New York Outdoor Weathering of GE Plastics Cycolac® /Geloy® Resin Systems Compared to PVC.[15] 25

20

∆E

15

10

5

0 Arizona

Florida

New York

PVC, White

PVC, Brown

C/G, White

C/G, Brown

Chapter 3

Acetal Category: Thermoplastic.

•

Ticona Celcon® , an acetal copolymer, is a crystalline engineering thermoplastic product.

•

Ticona Hostaform® , an acetal copolymer, is a specialty product in the range of engineering polymers. Hostaform LS grades are used for interior applications in a variety of colors with good light fastness and constant mechanical properties. Hostaform® black 10/1570 is used for exterior applications, and is UV stabilized and impact modified.

The wavelength of solar radiation that is harmful to polyacetals is in the range of 290–400 nm.[26] Damage to the material is triggered by absorption of UV light by the material. In the case of Hostaform® , little direct absorption in the critical UV region takes place because of the linkages in the polymer chain. This relatively good UV compatibility of polyacetal is limited, however, by unavoidable system-induced impurities and structural irregularities. And in all those cases where other polymers are incorporated [e.g., to improve the impact strength (blends)], the stability is further reduced. In practice, however, these effects are not noticed because extremely effective light stabilization systems have been developed for Hostaform® .[26] Improved weathering performance (retention of surface appearance as well as mechanical properties) is achieved in the Delrin® x07 series by the use of a selected UV stabilizer package.

•

BASF Ultraform® N 2325 U03, an acetal copolymer, is a UV stable injection molding grade developed specifically for use in outdoor applications, and is available in black only.

Weathering Properties: Colored Material

General Description: Acetal or polyoxymethylene (POM) resins are produced by the polymerization of purified formaldehyde [CH2 O] into both homopolymers and copolymers.

•

DuPont Delrin® , an acetal homopolymer resin, is a thermoplastic engineering polymer manufactured by the polymerization of formaldehyde. DuPont Delrin® x27 UV includes UV stabilization and is a UV resistant grade.

Weathering Properties: General Upon exposure to light, polyacetals that are not UV stabilized display loss of gloss, a change in color, and in some cases, chalking—the formation of a white coating on the surface. This degradation process is accompanied by a decrease in strength.

Colored molded parts show practically no color change or no surface changes after accelerated light exposure tests as per SAE J1885. Parts retain their “new car” appearance and do not show unsightly deposits or otherwise “chalk” during service life when made from Celcon® UV90Z. Celcon® UV colored grades meet standards recently introduced by major domestic car manufacturers requiring plastics in automotive interiors to be free of cadmium-based compounds.[27] Color stability tests using a Xenon Arc Weatherometer to simulate accelerated indoor/ outdoor exposure show that pigmented Celcon® UV90Z significantly outperforms competitive acetal and nonacetal products in resisting color degradation, easily passing the automotive SAE J1885

36

The Effects of UV Light and Weather on Plastics and Elastomers

Accelerated Indoor Weathering Test with an average of 0.6 CIELab units color shift (a color shift of more than +3.0 units fails SAE J1885). Celcon® UV90Z gave an average 380% lower color change after almost five times longer light exposure than acrylonitrile-butadiene-styrene, and was also superior to polypropylene and polyesters.[27] Celcon® parts retain a high percentage of their original mechanical properties during accelerated UV aging. After extreme light irradiation of 1240.8 kJ/m2 , Celcon® UV90Z retains almost 100% of its “as-molded” tensile strength, flex strength, flex modulus, and impact strength.[27] Hostaform® S 27072 WS black 10/1570 maintains very good UV stability during both accelerated weathering testing (xenon lamp) and outdoor testing (Florida and the Kalahari Desert).[28] Delrin® 507 BK601 compositions have shown excellent retention of strength properties after twenty years of outdoor exposure in Arizona, Florida, and Michigan. Over this period, essentially no loss of tensile strength occurred, but elongation was reduced to about 40% of the initial test value, with the greatest change in elongation occurring during the first six months of exposure.[29] For outdoor applications involving intermittent exposure, or a service of one to two years, colored Delrin® resins are generally suitable, based on mechanical property retention, because the colorant generally offers some UV-screening protection. High levels of carbon black act as an effective UV screen and are recommended for noncritical outdoor applications.[30] Delrin® x27 UV family of resins are of specially formulated colors, together with an optimized

UV stabilizer system. Delrin® x27 UV is intended for applications where parts are exposed to sunlight through glass, which includes automotive interior components and window hardware.[30] Even with UV-stabilized color compositions, surface dulling and chalking begin in about 6–8 months of exposure in Florida. The chalk may be removed by hand polishing in the early stages of development. If removal is delayed, the chalk layer hardens with time and becomes more difficult to remove.[29]

Weathering Properties: Unpigmented Material Celcon® M90UV or M270UV is recommended for unpigmented, natural, applications. It is white as molded, and provides extremely good protection against UV degradation and yellowing.[27]

Weathering Properties: Elevated Air Temperature Delrin® 500 maintains a tensile strength in excess of 55 MPa for approximately five years at 60◦ C. Test bars molded of Delrin® 500 have been stored for about twenty years in the absence of light at room temperature. After that time tensile strength, elongation at break, molecular weight, and notched Izod impact strength were unchanged, and the bars still retained their luster.[30]

37

3: Acetal

Weathering Properties by Material Supplier Trade Name Table 3-1. Color Differences, E, after Light Exposure for Pigmented Ticona Celcon® UV90Z (GM and Ford Automotive Colors) Material Family

Acetal, POM

Material Grade

Ticona Celcon® UV90Z

Reference Number

27

Exposure Conditions

SAE J1885 1240.8 kJ/m2

Exposure Energy Exposure Time Features

approx. 800 hrs GM Standard Black

GM Garnet Red

GM Very Dark Sapphire

GM Medium Beechwood

Ford Corporate Red

1.00

1.35

0.57

1.50

SURFACE AND APPEARANCE Color Change, E

0.17

Table 3-2. Color Differences, E, after Light Exposure for Pigmented Ticona Celcon® UV90Z Material Family

Acetal, POM

Material Grade

Ticona Celcon® UV90Z

Reference Number

27

Exposure Conditions

SAE J1885 1240.8 kJ/m2

Exposure Energy Exposure Time Features

approx. 800 hrs Black

Light Red

Light Tan

Medium Tan

Brown

0.2

0.2

0.2

0.6

0.2

Medium Gray

Dark Blue

Flame Red

Maroon

0.3

0.5

0.9

1.2

SURFACE AND APPEARANCE Color Change, E Features SURFACE AND APPEARANCE Color Change, E

38

The Effects of UV Light and Weather on Plastics and Elastomers

Table 3-3. Color Differences, E, after Light Exposure for Unpigmented Ticona Celcon® M90UV Material Family

Acetal, POM

Material Grade

Ticona Celcon® M90UV

Reference Number Exposure Conditions

27 Initial Value

HPUV

Exposure Time

Xenon Arc ASTM 4459

300 HP Units

200 hrs

600 hrs

1000 hrs

2.62

2.63

2.66

2.89

SURFACE AND APPEARANCE Initial b value

4.08

Color Change, b

Note: b is a color value; lower values mean whiter samples.

Table 3-4. Color Differences, E, after Florida Weathering for Ticona Hostaform® Materials Material Family

Acetal, POM Ticona Hostaform®

Material Grade S 27072 WS 10/1570

C 9021 10/1570

Reference Number

C 9021 LS 10/1570

28

Exposure Conditions

Xenotest 1200 CPS (EDAG) VW PV 3920 (Florida)

Exposure Time

1600 hrs

SURFACE AND APPEARANCE Color Change, E

1.8

2.4

0.8

Table 3-5. Color Differences, E, after Xenotest 1200 for Ticona Hostaform® C 9021 LS Blue 80/4065 Material Family

Acetal, POM

Material Grade

Ticona Hostaform® C 9021 LS Blue 80/4065

Reference Number

26

Exposure Conditions Exposure Time

Xenotest 1200 500 hrs

1000 hrs

1500 hrs

2000 hrs

1.2

1.3

1.6

2.2

SURFACE AND APPEARANCE Color Change, E Note: E is an approximate value.

39

3: Acetal

Table 3-6. Tensile Strength and Elongation after Arizona Weathering Exposure for DuPont Delrin® 507 BK601 Material Family

Acetal, POM

Material Grade

DuPont Delrin® 507 BK601

Reference Number

29

Exposure Conditions Exposure Time, years

Outdoor Arizona 0

1

2

3

4

10

20

70.3

71.0

71.7

71.0

73.1

69.6

70.2

20

12

11

9

11

10

8

MECHANICAL PROPERTIES Tensile Strength, MPa Elongation, %

Table 3-7. Tensile Strength and Elongation after Michigan Weathering Exposure for DuPont Delrin® 507 BK601 Material Family

Acetal, POM

Material Grade

DuPont Delrin® 507 BK601

Reference Number

29

Exposure Conditions Exposure Time, years

Outdoor Michigan 0

1

2

3

4

10

20

70.3

70.3

70.3

70.3

72.4

69.6

64.4

20

7

13

12

14

10

11

MECHANICAL PROPERTIES Tensile Strength, MPa Elongation, %

40

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 3-1. Relative Tensile Strength after Accelerated Interior Weathering According to SAE J1885 for DuPont Delrin® .[30] 1

Relative Tensile Strength

UV stabilized

Standard

0.5

0

0

500

1000

Exposure (kJ/m2)

Graph 3-2. Relative Gloss after Accelerated Interior Weathering According to SAE J1885 for DuPont Delrin® .[30]

1

Relative Gloss

X27UV BK

X07 BK 0.5

X00 BK

0

0

500

Exposure (kJ/m2)

1000

41

3: Acetal Graph 3-3. Changes in Mechanical Properties after Light Exposure of Ticona Celcon® UV90Z.[27] 104.5 100.0

105.2 100.8 96.7

Izod Impact, Notched

Flex Modulus

25.0

Flex Strength

50.0

Tensile Strength

Property Retention (%)

75.0

0

Mechanical Properties Note: Total light exposure energy: 1240.8 kJ/m2 (approx. 800 hrs).

Graph 3-4. Outdoor Exposure Time vs. Impact Strength Retained of BASF Ultraform® N 2320 and Ultraform® N 2325 U Acetal Copolymer.

42

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 3-5. New Jersey and Arizona Outdoor Exposure Time vs. Tensile Impact Strength of Ticona Celcon® M90 and UV90 Acetal Copolymer.

Graph 3-6. New Jersey and Arizona Outdoor Exposure Time vs. Tensile Strength at Yield of Ticona Celcon® M90 Acetal Copolymer.

3: Acetal

43

Graph 3-7. New Jersey Outdoor Exposure Time vs. Tensile Strength at Yield of Ticona Celcon® GC25 A Acetal Copolymer.

Graph 3-8. QUV Exposure Time vs. E Color Change of Ticona Celcon® Acetal Copolymer.

44

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 3-9. Sunshine Weatherometer Exposure Time vs. Elongation Retained of Mitsubishi Iupital® F20 Acetal Copolymer.

Graph 3-10. Sunshine Weatherometer Exposure Time vs. Tensile Strength Retained of Mitsubishi Iupital® F20 Acetal Copolymer.

3: Acetal

45

Graph 3-11. Xenon Arc Weatherometer Exposure Time vs. Relative Gloss of BASF Ultraform® N Acetal Copolymer.

Chapter 4

Acrylonitrile-Styrene-Acrylate Category: Acrylic, engineering resin. General Description:Acrylonitrile-styrene-acrylate (ASA) is an acrylonitrile copolymer modified with an acrylate rubber included during the polymerization stage. •

BASF Luran® S is a styrene-acrylonitrile copolymer that has been impact modified with acrylic ester rubber.[6]

•

GE Plastics’ Geloy® ASA resin is an advanced amorphous terpolymer of acrylicstyrene-acrylonitrile.[35]

Weathering Properties Luran® S demonstrates high resistance to weathering. A special acrylic ester rubber provides resistance to UV radiation and atmospheric oxygen. The toughness, as measured by the penetration energy on 2-mm thick disks of Luran® S, is maintained after significant exposure to sunshine. The ASA + PC (polycarbonate) blends and UV-stabilized Luran® S show particularly favorable performance.[6] As a weatherable material, Geloy® resin offers exceptional durability in all kinds of harsh environments. In outdoor applications, Geloy® resins retain their color stability under long-term exposure to UV, moisture, heat, cold, and impact.[35]

Degree of Discoloration The extent of yellowing (b) of Luran® S upon exposure to sunshine remains low for up to 4000 hours. UV-stabilized Luran® S shows particularly strong performance, demonstrating virtually no yellowing after 4000 hours of exposure. The very low level of yellowing of Luran® S after exposure to outdoor weathering is comparable with that of polyvinyl chloride, a material whose suitability for outdoor applications has been proven over many years of use.[6] Luran® S in dark shades displays very little tendency towards graying when it is exposed to UV radiation or outdoor weathering and subsequently brought into contact with hot water and detergent solutions, conditions that are common in automotive applications.[6] Dark colored Luran® S formulations have only a very slight tendency toward graying after weathering followed by contact with hot water or soap solution.[6]

Thermal Resistance The resistance of Luran® S to the effect of continuous heat has been demonstrated by storage experiments at 90◦ C. A slight decrease in toughness and a strong resistance to yellowing were detected over the duration of exposure.[36]

48

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 4-1. Color Properties after Florida (45◦ South Facing) Outdoor Exposure for Pigmented GE Plastics Geloy® Material Family

ASA

Reference Number

35

Features

Country Green Siding

Pebblestone Siding

EXPOSURE CONDITIONS Exposure Type

Outdoor 45◦

Exposure Location Exposure Time (months)

0

6

12

18

South Facing Florida 24

0

6

12

18

24

SURFACE AND APPEARANCE CIELab Color Coordinates and Color Shift (D/2◦ ) L

66.2

65.6

65.6

66.1

66.3

62.5

62.3

62.2

62.6

62.4

a

−6.8

−6.7

−6.7

−6.7

−6.8

1.4

1.4

1.3

1.4

1.3

b

7.8

7.7

8.3

8.3

8.3

11

10.9

11.3

11.4

11.2

E

0

0.6

0.8

0.5

0.5

0

0.2

0.4

0.4

0.2

L

0

−0.6

−0.6

−0.1

−0.1

0

−0.2

−0.3

0.1

−0.1

a

0

0.1

0.1

0.1

0

0

0

−0.1

0

−0.1

b

0

−0.1

0.5

0.5

0.5

0

−0.1

0.3

0.4

0.2

Table 4-2. Long-Term Material Performance for GE Plastics Geloy®[25] Material Property

Performance

UV Resistance

Outstanding

Color Retention

Outstanding

Heat Resistance

Outstanding

Thermal Aging

Excellent

Note: Assumptions include processing and grade expectations that suggest long-term performance (i.e., chemical resistance, chalking, impact, weatherability, strength retention).

4: Acrylonitrile-Styrene-Acrylate

49

Table 4-3. Yellowness Index after Outdoor Weathering in Ludwigshafen, Germany, for BASF Luran® S 776 S ASA Polymer

Graph 4-1. Yellowness Index after Outdoor Exposure for BASF Luran® S 797 and Luran® S 776 ASA Polymer.

50

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 4-2. Color Change, E, after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer.

Graph 4-3. Impact Strength Retained after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer.

4: Acrylonitrile-Styrene-Acrylate

51

Graph 4-4. Elongation at Break Retained after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer.

Graph 4-5. Gloss Retained after Outdoor Weathering in Okinawa, Japan, for Mitsubishi Rayon® ASA Polymer.

52

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 4-6. Impact Strength Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® T110 and T120 ASA Polymer.

Graph 4-7. Impact Strength Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® ASA Polymer.

4: Acrylonitrile-Styrene-Acrylate

53

Graph 4-8. Elongation at Break Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® ASA Polymer.

Graph 4-9. Gloss Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® T115 and T110 ASA Polymer.

54

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 4-10. Gloss Retained after Sunshine Weatherometer Exposure for Mitsubishi Rayon® ASA Polymer.

Graph 4-11. Impact Strength after Weatherometer Exposure for BASF Luran® S ASA Polymer at Different Test Temperatures.

55

4: Acrylonitrile-Styrene-Acrylate

Graph 4-12. Impact Strength after Xenotest 1200 Exposure for BASF Luran® S 797 and Luran® S 776 ASA Polymer.

Graph 4-13. Yellowness Index of ABS, Luran® S, and Blends after Exposure to Sunshine.[6] 35

Yellowness Index

30 25

ABS or PC + ABS

20 15 10 Luran S (ASA) 5 Luran S-UV (ASA)

0 –5

0

1000

2000

3000

Hours of Exposure to Sunshine

4000

56

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 4-14. Penetration Energy after Exposure to Sunshine on 2-mm Thick Disks of Luran® S 778 T, Luran S® 778 T UV, Luran® S KR 2861/1 C, ABS-UV, and PC + ABS.[6]

Penetration Energy (J)

70 Luran S KR 2861/1 C

60 50

(PC + ABS) 40 Luran S 778 T UV

30 20

Luran S 778 T

ABS-UV 10 0 0

500

1000

Hours of Sunshine

1500

2000

Chapter 5

Acrylic and Acrylic Copolymer Category: Acrylic thermoplastic. General Description: Polymethyl methacrylate (PMMA) is often just called “acrylic.” PMMA is the synthetic polymer of methyl methacrylate and is amorphous, transparent, and colorless. •

Atoglas Plexiglas®

•

Cyro Acrylite®

•

Novacor NAS® 36 and Zylar® 533 are clear, UV-stabilized resins for indoor applications

•

Lucite®

Many acrylic materials are offered as “capstock” materials that are extruded over a traditional substrate material such as polyvinyl chloride. The combination provides exceptional durability and performance characteristics including UV weathering to the siding or other substrate.

Weathering Properties The weatherability of the Acrylite® GP F acrylic sheet, Acrylite® GP FL acrylic sheet, and Acrylite®

GP FL W acrylic sheet was evaluated using a Xenon Arc Accelerated Weathering System. Test samples were compared to an unexposed sample at intervals of 1000, 2000, 3000, and 5000 hours. These exposures are approximately comparable to 1, 2, 3, and 5 years of Florida outdoor exposure. Both the edge and the surface colors were evaluated. Estimates of the number of years of Florida outdoor weathering exposure required for the material to undergo significant changes in color or edge appearance are given below.[37] Plexiglas® V-series of acrylic resins provide optical clarity and resistance to UV-light degradation and discoloration. Plexiglas® V825 and V920 series resins remain virtually unchanged after longterm outdoor exposure. Plexiglas® DR resin provides outstanding transparency and UV resistance during long-term outdoor exposure.[38] NAS® 36 and Zylar® 533 have been tested for resistance to indoor light exposure according to the conditions of ASTM D4459-99. These results indicate that NAS® 36 is very well suited for indoor applications. It retains its water-white color and sparkling clarity for extended periods of time under most indoor lighting environments. NAS® 36 has better color stability than many stabilized polycarbonates. Zylar® 533 has color stability similar to stabilized polycarbonates.[38]

58

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 5-1. Cyro Acrylite® GP F Acrylic Sheet after Xenon Arc Accelerated Weathering Material Family

Acrylic, PMMA

Material Grade

Acrylite® GP F

Reference Number

37

Exposure Conditions

Xenon Arc Accelerated Weathering System

Features

Red 2149-4

Orange 3141-5

Green 564-9

Number of years of Florida outdoor weathering exposure required for the material to undergo significant changes in color or edge appearance Years

3–4

1–2

0.5

Table 5-2. Cyro Acrylite® GP FL Acrylic Sheet after Xenon Arc Accelerated Weathering Material Family

Acrylic, PMMA

Material Grade

Acrylite® GP FL

Reference Number

37

Exposure Conditions

Xenon Arc Accelerated Weathering System

Features

Red 2149-4

Orange 3105-5

Number of years of Florida outdoor weathering exposure required for the material to undergo significant changes in color or edge appearance Years

5

3

Table 5-3. Cyro Acrylite® GP FLW Acrylic Sheet after Xenon Arc Accelerated Weathering Material Family

Acrylic, PMMA

Material Grade

Acrylite® GP FLW

Reference Number

37 Xenon Arc Accelerated Weathering System

Exposure Conditions Features

Red 2130-2

Dark Red 2135-1

Orange 3127-2

Yellow 4073-8

Green 5143-8

Blue 6157-9

Number of years of Florida outdoor weathering exposure required for the material to undergo significant changes in color or edge appearance Years

5

1–2

3

1–2

0.5

3

59

5: Acrylic and Acrylic Copolymer

Graph 5-1. Light Transmission for Acrylic, Cyrolon® UVP Polycarbonate Sheet, and Polycarbonate after Weathering Exposure* as per ASTM D1003.[39] 94

Percentage Transmission

Acrylic

91

Cyrolon UVP Polycarbonate Sheet 88 Polycarbonate

85

0

1

2

3

5

Years Equivalent Light Transmission per ASTM D1003

*1/8 sheet (nominal) EMMAQUA Accelerated Weathered (AZ), DSET Laboratories Inc.

Graph 5-2. Yellowness Index for Acrylic, Cyrolon® UVP Polycarbonate Sheet, and Polycarbonate after Weathering Exposure* as per ASTM D1925.[39] 12 Polycarbonate

Yellowness Index

10

8

6

4

Cyrolon UVP Polycarbonate Sheet

2 Acrylic 0

1

2

3

5

Years Equivalent Yellowness Index per ASTM D1925

*1/8 sheet (nominal) EMMAQUA Accelerated Weathered (AZ), DSET Laboratories Inc.

60

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 5-3. Percentage Haze for Acrylic, Cyrolon® UVP Polycarbonate Sheet, and Polycarbonate after Weathering Exposure* as per ASTM D1003.[39] 10

8

Percentage Haze

Polycarbonate

6

4

Cyrolon UVP Polycarbonate Sheet

2 Acrylic

0

1

2

3

5

Years Equivalent Haze Index per ASTM D1003

*1/8 sheet (nominal) EMMAQUA Accelerated Weathered (AZ), DSET Laboratories Inc.

61

5: Acrylic and Acrylic Copolymer

Graph 5-4. Luminous Transmittance, Haze, Yellowness Index, and Surface Gloss of Plexiglas® V825 after Florida and Arizona Weathering.[38] Luminous Transmittance

Haze

95.0

20.0 Florida Arizona 15.0

% Haze ASTM D1003

% Transmittance ASTM D1003

92.0 89.0 86.0

10.0

5.0

83.0

Florida Arizona 0.0

80.0 0

1

2

3

0

5

1

Years

3

5

Surface Gloss

Yellowness Index 10.0

100 Florida

9.0

95

Arizona

60° Specular Gloss ASTM D523

8.0

Yellowness Index ASTM D1925

2

Years

7.0 6.0 5.0 4.0 3.0 2.0

90 85 80 75 70 65 60

Florida

1.0

55

Arizona

0.0

50 0

1

2

Years

3

5

0

1

2

Years

3

5

62

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 5-5. Luminous Transmittance, Haze, Yellowness Index, and Surface Gloss of Plexiglas® DR101 after Florida and Arizona Weathering.[38] Luminous Transmittance

Haze

95.0

20.0 Florida Arizona 15.0

% Haze ASTM D1003

% Transmittance ASTM D1003

92.0 89.0 86.0

10.0

5.0

83.0

Florida Arizona 0.0

80.0 0

1

2

3

0

5

1

Years

3

5

Surface Gloss

Yellowness Index 10.0

100 Florida

9.0

95

Arizona

60° Specular Gloss ASTM D523

8.0

Yellowness Index ASTM D1925

2

Years

7.0 6.0 5.0 4.0 3.0 2.0

90 85 80 75 70 65 60

Florida

1.0

55

Arizona

0.0

50 0

1

2

Years

3

5

0

1

2

Years

3

5

63

5: Acrylic and Acrylic Copolymer

Graph 5-6. Luminous Transmittance, Haze, Yellowness Index, and Surface Gloss of Plexiglas® V920 after Florida and Arizona Weathering.[38] Luminous Transmittance

Haze

95.0

20.0 Florida Arizona 15.0

% Haze ASTM D1003

% Transmittance ASTM D1003

92.0 89.0 86.0

10.0

5.0

83.0

Florida Arizona 0.0

80.0 0

1

2

3

0

5

1

2

Years

5

Surface Gloss

Yellowness Index 10.0

100 Florida

9.0

95

Arizona

60° Specular Gloss ASTM D523

8.0

Yellowness Index ASTM D1925

3

Years

7.0 6.0 5.0 4.0 3.0 2.0

90 85 80 75 70 65 60

Florida

1.0

55

Arizona

0.0

50 0

1

2

3

5

0

1

2

3

5

Years

Years

Graph 5-7. Color Change, E, after Atlas Weatherometer Exposure of Novacor NAS® 30, NAS® 36, Zylar® 533, and Other Materials.[40] ASTM D4459 (G155, Cycle #4) 5

NAS 30

Color Change (∆E)

NAS 36 4

ZYLAR 533 GP PMMA

3

UV stable PC

2

1

0 0

150

300

450

600

Xenon Arc Exposure Time (hours) Note: ASTM D4459-99 testing was performed in accordance with Method G155-00a (Table X3.2, Cycle #4) on an Atlas Ci65A Weather-Ometer® at a xenon irradiance of 0.30 W/m2 and a black panel temperature of 55◦ C.

Chapter 6

Acrylic and Polyvinyl Chloride Coextrusion Category: Coextrusion and blends. General Properties: Lucite TufCoat® is used for architectural capping (capstock). TufCoat® is literally extruded over a traditional substrate material such as polyvinyl chloride (PVC) to provide exceptional durability and performance characteristics to the siding.[41]

Weathering Properties Halogen-containing polymers (e.g., PVC) are relatively cheap and readily available materials. They have been used outdoors in buildings and glazing. However, the weatherability (e.g., the light stability)

of halogen-containing polymers is poor, leading to relatively short lifetimes particularly in pigmented formulations.[42] Acrylic materials are used in a variety of applications because of their toughness, weatherability, appearance, and stability characteristics. Thus they are often used as capstock material to provide a coating layer over a substrate thermoplastic material and provide the advantageous properties of acrylic compounds to the underlying thermoplastic material.[42] TufCoat® provides UV weathering resistance to a PVC substrate, which means that manufacturers can offer a much wider range of color options safe in the knowledge that the products will not fade or change color over time.[41]

Chapter 7

Cellulose Acetate Butyrate Category: Cellulosics. General Description: Cellulosics are synthetic plastics made from a naturally occurring polymer, cellulose, obtained from wood pulp and cotton linters. Cellulose must be chemically modified to produce a thermoplastic material. Cellulose acetate butyrate is a cellulose ester. •

Eastman Tenite® butyrate is a plastic produced from cellulose acetate butyrate. Various formulations of Tenite® butyrate have different degrees of resistance to solar radiation. The most weather-resistant butyrate formulations are typified by Tenite® butyrate 465. The most used formulas maintain material properties for five years or more when exposed continuously in Arizona and include Tenite® butyrate 465, 485, and 513.[2]

Weathering Properties Cellulose esters, like most polymeric materials, degrade when exposed to weathering. Special outdoor formulations may remain useful for at least five years outdoors in any part of the continental United States and in other areas of the world with comparable climates. Cellulose esters can be partially protected from the direct chain scission and the photo-catalyzed oxidation using UV inhibitors or UV stabilizers; protection from oxidation is obtained with antioxidants.[2] The deterioration in cellulosics caused by weathering depends on the particular cellulose ester, plasticizer, stabilizer system, wavelength of the incident radiation, total amount of radiation absorbed, temperature of the plastic, atmospheric humidity,

industrial contaminants in the atmosphere, and possibly other factors.[2] Deterioration of cellulosic plastics caused by weathering first appears as a dulling of the surface. As deterioration proceeds into advanced stages, the surface crazes and cracks; the formation of each fissure exposes the underlying plastic to the action of the weather. The onset of surface crazing does not mean the end of the usefulness of Tenite® butyrate. It will still have good tensile strength, elongation, and impact strength. Elongation is one of the best methods for determining the toughness of a plastic. A brittle material will break with little elongation and will show a smooth, glassy break. A tough material will show a ductile break with good elongation before breaking occurs.[2] Actual outdoor performance is the most reliable criterion by which the outdoor usefulness of a plastic can be judged. Eastman’s outdoor weathering program involves the exposure of many hundreds of samples at weathering stations in Kingsport, Tennessee (Lat. 36◦ 32 N, Long. 82◦ 34W, El. 1200 ft); Homestead, Florida (Lat. 26◦ 38 N, Long. 81◦ 51W, El. 9 ft); and Phoenix, Arizona (Lat. 33◦ 27 N, Long. 112◦ 3W, El. 1080 ft).[2]

Color Retention Articles made of outdoor types of Tenite® butyrate in suggested colors should give at least five years of service under even the most adverse weather conditions found in the continental United States. These most adverse conditions represent exposure to solar radiation that measures approximately 185,000 langleys per year on a horizontal surface and are found, in general, south of about 35◦ N latitude and between about 100◦ and 115◦W longitude. Comparable exposure in other parts of the world should have similar effects.[2]

68

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Graph 7-1. Tensile Strength at Break after Arizona Weathering for Eastman Tenite® Butyrate.[2] 6,000

5,500

35

5,000

4,500

Tensile Strength (psi)

Tensile Strength (MPa)

40

30 0

10

20

30

4,000 50

40

Exposure Time (months) Note: 3.2-mm (0.125-in.) thick specimens of an outdoor type of Tenite® butyrate.[14]

Graph 7-2. Elongation at Break after Arizona Weathering for Eastman Tenite® Butyrate.[2] 50

Elongation (%)

40

30 Black 20

Clear and Colors

10

0 0

10

20

30

Exposure Time (months) Note: 3.2-mm (0.125-in.) thick specimens of an outdoor type of Tenite® butyrate.

40

50

69

7: Cellulose Acetate Butyrate

30

40

Black

35

Clear and Colors 25

30 20 25 15

20 15

10

10 5

Impact Strength [ft·lbt at 23°C (73°F)]

Impact Strength [J at 23°C (73°F)]

Graph 7-3. Impact Strength after Weathering for Eastman Tenite® Butyrate.[2]

5 0

1

2

3

0

Time (years) Note: 3.2-mm (0.125-in.) thick specimens of an outdoor type of Tenite® butyrate; samples weathered in a vertical position facing due south. Testing as per ASTM D3029.

Chapter 8

Fluoropolymers: Overview

Due to the unique nature of the carbon–fluorine bond, most traditional fluoropolymers have the ability to withstand continuous outdoor exposure.[43] In a study of weathering resistance, three partially fluorinated polymers (ETFE, PVDF, and PVF) were exposed to UV light in a QUV Weatherometer, Q-Panel Co., at 50◦ C. The machine was equipped with UV lamps producing rays in the wavelength range of 313–550 nm. The difference between the resistance of these three fluoroplastics was characterized by the change in tensile properties as a result of exposure over time. ETFE had the most resistance in that break elongation, tensile strength, and modulus did not change upon exposure. Tensile strength and tensile modulus of PVDF remained constant while its break elongation decreased.All three properties of

Tensile Modulus (GPa)

Graph 8-1. Mechanical Properties of PVDF, ETFE, and PVF Films after South Florida Exposure.[43]

Tensile Strength (MPa)

Fluoropolymer Weathering

PVF declined. Fluorine content, in addition to molecular structure, influences the UV light resistance of the fluoropolymer. Deficiencies have been overcome by incorporating organic absorbers and inorganic absorbing pigments (e.g., titanium dioxide).[43]

2.5 2.0 PVDF

1.5 1.0

ETFE

0.5

PVF

0

0

400

800 1200 1600 Irradiation Time (hrs)

2000

2400

100 80 60

ETFE PVDF

40 20

PVF

0

200

400

1000

1400

1800

2200

Irradiation Time (hrs) ETFE

400 Elongation (%)

The fluorocarbon family is made up of several branches. By varying the fluorine content of the polymer, the balance of mechanical properties can be tailored for different end use applications. As the fluorine content of a polymer increases, its resistance to chemicals and weathering, including UV resistance, also increases. Mechanical properties deteriorate with increasing fluorine content. Fully fluorinated polymers include polytetrafluoroethylene (PTFE or TFE), fluorinated ethylene propylene (FEP), and perfluoroalkoxy (PFA); partially fluorinated polymers include polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene (ECTFE), ethylenetetrafluoroethylene (ETFE), and polyvinylfluoride (PVF).

300 200 PVDF

100

PVF

0 0

400

800

1200

1600

Irradiation Time (hrs)

2000

2400

Chapter 9

Polytetrafluoroethylene (PTFE or TFE) Category: Fluoropolymer.

Weathering Properties

General Properties: PTFE is completely unaffected by outdoor weathering. Studies have shown it to be unaffected even after twenty-five years of exposure in Florida.[44]

The outdoor weatherability of PTFE is due to its molecular structure and not as a result of additives.

•

PTFE is also known as DuPont Teflon®

Weathering Properties by Material Supplier Trade Name Table 9-1. Mechanical Properties of PTFE Film after South Florida Exposure[43] Tensile Strength (MPa)

Break Elongation (%)

Years of Exposure MD

TD

MD

TD

0

45.5

8.5

320

400

10

31.5

14.9

190

390

Property Retention (%)

69

175

59

98

Note: MD, machine direction; TD, transverse direction.

Chapter 10

Fluorinated Ethylene Propylene (FEP) Category: Fluoropolymer.

Weathering Properties

General Properties: FEP films remain essentially unchanged after twenty years of outdoor exposure with no evidence of discoloration, UV degradation, or strength loss. This outstanding performance is due to the structure of the polymer molecule and is not the result of chemical additives.[45]

Tensile strength, break elongation, and electrical properties are essentially unchanged after twenty years of outdoor exposure in South Florida.[43]

Weathering Properties by Material Supplier Trade Name Table 10-1. Mechanical Properties after 20-Year South Florida Exposure for Two Thicknesses of FEP Film[43]

Film Thickness (µm)

Years of Exposure

50

Tensile Strength (MPa)

Break Elongation (%)

Tensile Modulus (MPa)

MD

TD

MD

TD

MD

TD

0

21.4

18.6

270

290

462

407

50

5

20

13.8

365

310

462

407

50

7

20

16.6

290

300

428

434

50

10

18.6

16.6

145

221

428

476

50

15

19.4

15.4

200

190

–

–

500

0

21.4

20

470

435

496

538

500

6

20

20

580

575

476

469

500

10

20.7

17.2

515

415

455

503

500

15

25.3

25.7

330

334

–

–

500

20

21.1

22.0

292

294

–

–

Note: MD, machine direction; TD, transverse direction.

76

The Effects of UV Light and Weather on Plastics and Elastomers

Table 10-2. Tensile Strength and Break Elongation after 20-Year South Florida Exposure for Two Thicknesses of FEP Film[43] Tensile Strength (% of initial retained)

Break Elongation (% of initial retained)

MD

TD

MD

TD

20

91

84

74

65

20

100

110

62

68

Film Thickness (µm)

Years of Exposure

50 500

Note: MD, machine direction; TD, transverse direction.

Table 10-3. Material Properties (Dielectric Strength, Tensile Strength, Elongation at Break, and MIT Flex Life) of FEP Film after South Florida Exposure[43]

Length of Exposure (months)

Dielectric Strength (kV/mm)

0

Machine Direction

Transverse Direction

Tensile Strength (MPa)

Elongation at Break (%)

Tensile Strength (MPa)

Elongation at Break (%)

MIT Flex Life (cycles)

124

18.0

295

15.9

300

24,000

3

112

18.8

305

16.8

265

16,300

6

132

19.0

310

16.9

300

24,400

12

132

15.9

280

15.0

305

17,400

Note: 75 µm = 0.003 in.

Table 10-4. Material Properties (Tensile Strength and Elongation at Break) of FEP Film after South Florida Exposure[43]

Length of Exposure (months)

Machine Direction

Transverse Direction

Tensile Strength (MPa)

Elongation at Break (%)

Tensile Strength (MPa)

Elongation at Break (%)

0

19.9

306

23.9

294

6

21.1

276

18.5

279

12

19.9

285

23.2

305

Note: 250 µm = 0.010 in.

77

10: Fluorinated Ethylene Propylene (FEP) Table 10-5. Electrical Properties of FEP Film after South Florida Exposure[43] Length of Exposure (months)

Dielectric Strength (kV/mm)

Dielectric Constant (1 kHz)

Dissipation Factor (1 kHz)

0

60

2.3

0.00015

6

82

2.4

0.00035

12

79

2.2

0.0002

Note: 250 µm = 0.010 in.

3000

21 All Film Thicknesses

14 0

2000 0 600

Elongation (%)

500

Tensile Strength (MPa)

Tensile Strength (psi)

Graph 10-1. Retention of Tensile Strength and Percentage Elongation after Outdoor Exposure for DuPont FEP Film.[45]

50 µm/20 mils

400 300

125–250 µm/5–10 mils

200

50 µm/2 mils

100

25 µm/1 mil

0 0

2

4

6

8

10

12

14

Exposure Time (years)

16

18

Chapter 11

Perfluoroalkoxy (PFA and MFA) Category: Fluoropolymer.

Weathering Properties

General Properties: PFA is a semi-crystalline, fully fluorinated, melt-processable fluoropolymer. PFA resins are copolymers of tetrafluoroethylene with perfluorinated vinyl ethers. MFA is a copolymer of perfluoromethylvinyl ether and tetrafluoroethylene. MFA is a class of modified PFA resins that has lower performance and somewhat lower cost compared to standard PFA. Commercial PFAs are generally copolymers of perfluoropropylvinyl ether and tetrafluoroethylene.[46]

PFA is unaffected by long periods of exposure to direct sunlight, wind and rain, and exhaust gases.[47] The high clarity, low haze structure of MFA films provides excellent performance in applications requiring clear films, such as solar collectors and cell culture bags, and in UV sterilization applications.[48]

Graph 11-1. Color Change, E, after Carbon Arc Weatherometer Accelerated Weathering (Dew Cycle) for PFA and MFA.[49] 4.5 4

∆E (CIELab)

3.5 3 2.5 2 1.5 1 0.5 0 0

100

200

300

400

500

600

Exposure Time (hrs) PFA

MFA

700

800

900

1000

80

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 11-2. Tensile Strength Retention after Carbon Arc Weatherometer Accelerated Weathering (Dew Cycle) for PFA and MFA.[49]

Tensile Strength Retention (%)

120

100

80

60

40

20

0 0

100

200

300

400

500

600

700

800

900

1000

Exposure Time (hrs) PFA

MFA

Graph 11-3. Elongation Retention after Carbon Arc Weatherometer Accelerated Weathering (Dew Cycle) for PFA and MFA.[49]

Elongation Retention (%)

120 100 80 60 40 20 0 0

100

200

300

400

500

600

Exposure Time (hrs) PFA

MFA

700

800

900

1000

Chapter 12

Polyvinylidene Fluoride (PVDF) Category: Fluoropolymer. General Properties: PVDF has good weathering properties.[50] It is insensitive to UV light and does not need to be protected. Its insensitivity to UV light results in remarkable gloss retention even after natural or accelerated weathering.[51] PVDF is often used as the topcoat in capstock (a single or multilayer film that protects a plastic substrate such as polyvinyl chloride, acrylonitrilebutadiene-styrene, polycarbonate, or polyamide). Because it is completely transparent to UV wavelengths, PVDF used as topcoats contain UV absorbers to protect the substrate from damage. PVDF capstock can be formulated to last for as long as 10–30 years.[52]

Weathering Properties Transparent Arkema Kynar® Films are formulated with nonmigrating organic UV absorbers to screen natural light and protect the substrate from UV damage.[51] 1. Be 99% opaque (absorbance > 2) up to 400 nm for 2000 hours in the SEPAP 12-24∗ accelerated weathering test. 2. Ensure a gloss retention > 80% and a color shift E < 2 after 1000 hours in weatherometer accelerated testing∗∗ (a typical requirement in automotive applications).

The absorbance at 320 nm can be plotted as a function of time to visualize the performance of the film. It can be seen that a 50-µm thick film maintains 99% UV opacity (absorbance > 2) for more than 2000 hours and is still 90% UV opaque (absorbance > 1) after 4000 hours of accelerated weathering in the SEPAP 12-24 test.[51] The mechanical properties of Kynar® film are maintained throughout many years of outdoor exposure. Clear films exposed to the sun at a 45◦ angle south retained their tensile strengths over a 17-year period. During the first few months of exposure when normal crystallization takes places, the percentage of elongation at break decreases to a level that remains essentially constant with time. In addition, the weathered films remain flexible and are capable of being bent up to 180◦ without cracking.[53] Arkema Kynar® 500 is a special grade of PVDF resin used by licensed industrial paint manufacturers as the base resin in long-life coatings called coil coatings.[54] Solvay Solexis Halar® 5000 LG and HG are specifically designed for solvent-based coatings to provide improved gloss. The weathering characteristics of Hylar® 5000 coatings lead to excellent performance for the long term.[42] Solvay Solexis Halar® 5000 PVDF films are highly resistant to most environmental conditions including gamma radiation and are essentially transparent to UV radiation.[52] Solvay Solexis Solef ® 11010 and Solef ® 21508 are PVDF copolymers.

∗ SEPAP

12-24: Climate chamber equipped with four artificial lamps (mercury vapor: unit power 400 W) with cutoff of UV radiation below 300 nm; samples are continuously exposed without water sprinkling; temperature is maintained at 60◦ C. Note that the SEPAP 12-24 test is extremely demanding since the UV exposure is permanent (no night and day cycle). ∗∗ WOM CI135A: Climate chamber equipped with three artificial lamps (xenon arc: 63 W/m2 between 300 and 400 nm) with

cutoff of UV radiation below 290 nm; samples are exposed alternatively to the lamps and sprinkled with water for 18 min every 102 min; relative humidity is maintained at 50% and temperature at 70◦ C (dry period).

82

The Effects of UV Light and Weather on Plastics and Elastomers

Table 12-1. Mechanical Properties and Yellowness Index after Arizona Outdoor Weathering Exposure for Solvey Solexis Solef® 11010 Material Family

Polyvinylidene fluoride (PVDF)

Material Grade

Solvay Solexis Solef® 11010

Reference Number

49

Exposure Conditions

Outdoor Arizona

Sample Thickness (µm)

75

Exposure Time (years)

0

0.5

1

6

9

Tensile Impact (kJ/m2 )

3410

2796

2318

2707

–

Tensile Strength at Yield (MPa)

21.5

23.3

24.7

24.1

25

Elongation at Yield (%)

21

–

–

9.5

10.1

Tensile Strength at Break (MPa)

54

43.7

48.6

55.7

54.3

Elongation at Break (%)

470

374

380

410

416

Elmendorf Tear Strength (N)

2.5

1.5

1.5

3.5

3.1

1.9

4.1

3.4

1.2

4.7

MECHANICAL PROPERTIES

SURFACE AND APPEARANCE Yellowness Index

Table 12-2. Yellowness Index after QUV Accelerated Weathering Exposure (UV-B 313) for Solvey Solexis Solef ® 21508 Material Family

Polyvinylidene fluoride (PVDF)

Material Grade

Solvay Solexis Solef® 21508

Reference Number

49

Exposure Conditions

UV-B 313, ASTM D1925

Exposure Time (hrs)

0

200

600

1200

2000

4000

Yellowness Index

–0.9

–0.5

–0.5

–0.4

–0.4

–0.3

L*

93.4

93.0

92.9

93.1

93.1

93.0

a*

–1.0

–0.9

–0.9

–0.9

–0.9

–0.9

–0.1

0.1

0.1

0.1

0.1

0.2

116

106

93

101

98

76

SURFACE AND APPEARANCE

b* Gloss at

60◦

*CIE 1976 measured by

Hunterlab—D65/10◦ .

12: Polyvinylidene Fluoride (PVDF)

83

Table 12-3. Retention of Mechanical Properties after Outdoor Weathering of Arkema Kynar® PVDF Film

Table 12-4. Retention of Mechanical Properties after Xenon Arc Weatherometer Exposure of PVDF

84

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 12-1. Retention of Tensile Strength and Elongation after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for PVDF Film.[49] 120

Retention (%)

100

80

60

40

20

0 0

1

2

3

4

5

Exposure Time (years) Retention of Tensile Strength

Retention of Elongation

Graph 12-2. Color Change, E, after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for Solvay Solexis Hylar® 5000 PVDF Pigmented Coatings.[49] 5 4.5 4

∆E (CIELab)

3.5 3 2.5 2 1.5 1 0.5 0 0

1

2

3

4

5

6

7

8

Aging Time (years) Blue

Brown

Yellow

Green

Black

9

10

85

12: Polyvinylidene Fluoride (PVDF)

Graph 12-3. Gloss Retention after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for Solvay Solexis Hylar® 5000 PVDF Pigmented Coatings.[49] 120

Gloss Retention (%)

100

80

60

40

20

0 0

1

2

3

4

5

6

7

8

9

10

Aging Time (years) Blue

Brown

Yellow

Green

Black

Graph 12-4. Chalk Rating after Florida Exposure (45◦ Angle South) for Commercial White Paints.[56] 10 PVDF 9

Silicone Polyester

8 Acrylic

Chalk Rating

7 6

Plastisol

5 4 3

Urethane

2 1 0

0

2

4

6

Exposure Time (years)

8

10

86

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 12-5. Gloss Retention after Florida Exposure (45◦ Angle South) for Commercial White Paints.[56] 120 PVDF

Gloss Retention (%)

100

80

Silicone Polyester

60

40

Acrylic

20

Vinyl Plastisol Urethane

0 0

2

4 6 Exposure Time (years)

8

10

Chapter 13

Polychlorotrifluoroethylene (PCTFE) Category: Fluoropolymer. General Properties: Honeywell Aclar® PCTFE films are extremely resistant to UV radiation, as tested in a weatherometer with water spray.[57]

Graph 13-1. Elongation Retained in the Machine Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE.

88

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 13-2. Elongation Retained in the Transverse Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE.

Graph 13-3. Tensile Strength Retained in the Machine Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE.

13: Polychlorotriﬂuoroethylene (PCTFE)

89

Graph 13-4. Tensile Strength Retained in the Transverse Direction after Weatherometer Exposure of Honeywell Aclar® 22A and Aclar® 33C PCTFE.

Chapter 14

Ethylene-chlorotrifluoroethylene (ECTFE) Category: Fluoropolymer.

Weathering Properties

General Properties: ECTFE undergoes very little change in properties or appearance on outdoor exposure to sunlight.

Solvay Solexis Halar® ECTFE shows no change after 1000 hours in a weatherometer.[58]

Table 14-1. Accelerated Weathering of Solvay Solexis Halar® ECTFE in a Xenon Arc Weatherometer

92

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 14-1. Retention of Tensile Strength and Elongation after Miami, Florida, Outdoor Weathering Exposure (45◦ Angle South) for Solvay Solexis Halar® ECTFE Film.[49]

100

Retention (%)

80

60

40

20

0 0

1

2

3

4

5

6

7

8

9

Exposure Time (years) % Retention of Tensile Strength

% Retention of Elongation

Graph 14-2. Retention of Tensile Strength and Elongation after QUV Accelerated Weathering Exposure, UVB-313, for Solvay Solexis Halar® ECTFE Film.[49]

100

Retention (%)

80

60

40

20

0 0

500

1000

1500

2000

2500

3000

3500

4000

Exposure Time (hrs) Retention of Tensile Strength

Retention of Elongation

4500

5000

93

14: Ethylene-chlorotrifluoroethylene (ECTFE)

Graph 14-3. Color Change, E, after QUV Accelerated Weathering Exposure, UVB-313, for Solvay Solexis Halar® ECTFE Film.[49] 5

∆E (CIELab)

4

3

2

1

0 0

500

1000

1500

2000

2500

3000

Exposure Time (hrs) Halar ECTFE Film

3500

4000

4500

5000

Chapter 15

Ethylene-tetrafluoroethylene (ETFE) Category: Fluoropolymer.

Weathering Properties

General Properties: ETFE has high weathering resistance, showing no deterioration or change in properties as a result of exposure to direct sunlight, wind and rain, and exhaust gases.[58]

Exposure of DuPont Tefzel® 200 for more than one year in Florida and Michigan has had no effect.[59] DuPont Tefzel® films have excellent outdoor weathering performance.[60]

Table 15-1. Accelerated Weathering of DuPont Tefzel® 200 ETFE in a Weatherometer

Chapter 16

Polyvinyl Fluoride (PVF) General Description •

DuPont Tedlar® PVF film

•

DuPont Tedlar® SP PVF

Weathering Properties PVF has outstanding weathering properties.[50] Pigmented Tedlar® , when properly laminated to a variety of substrates, imparts a long service life.[61] DuPont Tedlar® PVF film has excellent resistance to sunlight degradation, stands up well to atmospheric pollutants, and is resistant to acid rain attack and mildew. Most airborne dirt does not adhere to Tedlar® film.[61] Tedlar® is available as a pigmented or nearcolorless, transparent film. The pigmented films offer the highest level of protection from UV light degradation, as the pigments block nearly all UV and visible light from passing through the film. This means that the materials underneath the film will not be exposed to high-energy, destructive light.[61]

The transparent films are available in an enhanced UV-screening formula that blocks nearly all of the UV light up to 350 nm. These UV-absorbing films screen out progressively less UV light at the less harmful, lower energy end of the UV spectrum (350–400 nm) and block very little visible light.[30] Unsupported transparent Tedlar retains at least 50% of its tensile strength after ten years of exposure in Florida at an angle of 45◦ facing south.[61] Most colors exhibit no more than five NBS units (modified Adams color coordinates) of color change after twenty years of vertical, US outdoor exposure.[61] Tedlar® SP films match or exceed the resistance of high-quality plastic surfacing materials to color fade and loss of gloss. Color retention of Tedlar® SP films is dependent upon the color being tested.[62] High-gloss Tedlar® SP films have been found to perform similarly to original equipment manufacturer basecoat/clearcoat paints for gloss retention under xenon arc weathering, and provide superior gloss retention compared to other high-gloss films, refinish paints, and coextrusions.[62]

98

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 16-1. Percentage of Initial Properties Retained after South Florida Weathering Exposure at an Angle of 45◦ Facing South for DuPont Tedlar® PVF Film.[63] 100

Tensile

% of Initial Properties Retained

80

Elongation 60

40

20

0

1

2

3

4

5

6

Exposure Time (years)

Graph 16-2. Percentage Gloss Retention after South Florida Weathering Exposure at an Angle of 45◦ Facing South for DuPont Tedlar® PVF Film and Pigmented Vinyl Film.[61]

100

60° Gloss Retention (%)

80

60

40 TUT10BG3 Tedlar ® Film Pigmented Vinyl 20

0 0

1

2

3

Exposure Time (years)

4

5

99

16: Polyvinyl Fluoride (PVF)

Graph 16-3. Average Rate of UV Absorber Degradation in Free-Standing DuPont Tedlar® PVF Film after Florida Exposure.[61] 100

Initial Absorbance at 360 nm (%)

80

60

40

20

0

0

2

4

6

8

10

Florida Exposure (years; 45° Angle, Facing South)

Graph 16-4. Color Stability of DuPont Tedlar® PVF Film after Exposure to Atlas Sunshine Arc Weatherometer.[63] 5

Color Stability

4

3

2

1

0 1000

2000

3000

Exposure Time (hrs) Note: Colored films vary slightly in color retention, depending on color.

4000

5000

100

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 16-5. Percentage of Initial Properties Retained after Atlas Sunshine Arc Weatherometer Exposure of DuPont Tedlar® PVF Film.[63] 100

Tensile % of Initial Properties Retained

80

60

Elongation

40

20

0

2000

4000

6000

8000

Exposure Time (hrs)

Graph 16-6. Typical Color Change Range of a Variety of Pigmented DuPont Tedlar® SP Films after Xenon Arc Exposure as per the SAE J1960 Method.[62] 5

∆E (CIE94)

4

3

2

1

0 0

1200

2400

3600

Exposure (kJ)

4800

6000

7200

101

16: Polyvinyl Fluoride (PVF)

Graph 16-7. Gloss Retention of Refinish Paint, Gel Coat, and DuPont Tedlar® SP Film after Xenon Arc Exposure as per the SAE J1960 Method.[62] 100

60° Gloss

80

60

40

Tedlar ® SP Film Gel Coat

20

Refinish Paint 0 0

600

1200

1800

2400

Exposure (kJ)

Graph 16-8. Gloss Retention of Acrylic Film, ASA/AES Copolymer, and DuPont Tedlar® SP Film after Xenon Arc Exposure as per the SAE J1960 Method.[62] 100

60° Gloss

80

60

40

Tedlar ® SP Film Acrylic Film

20

ASA/AES Copolymer 0 0

600

1200

Exposure (kJ)

1800

2400

Chapter 17

Ionomer Category: Thermoplastic elastomer (TPE). General Properties: Ionomers are thermoplastic copolymers that can be processed like thermoplastics and demonstrate mechanical properties like elastomers or cross-linked polymers.[64]

Weathering Properties Ionomers have poor weathering resistance and must be stabilized if they are exposed to sunlight or outdoor weather. Outdoor weathering experience has confirmed the outstanding performance of UV-stabilized DuPont Surlyn® . Parts containing carbon black have been in service and exposed to all types of weather for over ten years with no significant change in physical integrity or appearance. Other pigmented parts have retained their physical integrity and appearance after five years of exposure to an Arizona environment.[65] Production samples of automotive exterior trim extrusions coated with clear, UV-stabilized Surlyn® and clear, UV-stabilized polyvinyl chloride were exposed side by side in up to 5000 hours of accelerated weathering tests. Besides the obvious edge in UV stability, Surlyn® ionomer resin requires no liquid plasticizer, and therefore there will be no migration problems in the finished part.[66] The most traditional and positive method of stabilizing ionomers for long-term usage in allweather environments requires the addition of 0.2% antioxidant and 5% (by weight) of well-dispersed, micrometer-sized carbon black. With this modification, products made from DuPont Surlyn® have been in continuous service for over ten years.[65] The development of technology for stabilizing clear or color-pigmented ionomers is a dynamic process. Earlier recommendations, based on the incorporation of antioxidant and UV absorbers, have produced pigmented products that still retain their

physical integrity and appearance after five years of normal exposure to an Arizona environment.[65] Subsequent development of newer stabilizers and “energy quencher” additives has led to broader recommendations for both clear and pigmented systems. There is no complete, comprehensive system for UV protection. However, based on continued research with accelerated testing and evaluation of long-term Florida exposure, it is possible to present a series of basic rules that provide an opportunity to customize the use of polymer modifiers.[65] The six basic rules for UV protection in ionomers are:[65] 1. Use zinc type ionomers for a more stable base and long-term performance. 2. It is essential to use antioxidants with all stabilizer systems. 3. Both sodium and zinc type ionomers may be modified for protection from occasional exposure to sunlight (less than 200 hours/year). 4. For maximum retention of tensile and impact properties, a combination of an antioxidant (UV absorber) and an energy quencher must be used. In pigmented parts, this should not present any limitations in product appearance. However, in clear, transparent applications, the presence of currently recommended UV absorbers may create unacceptable levels of yellowness, depending upon the part thickness. 5. When maximum retention of clarity, surface brilliance, and absence of color formation are primary end-use considerations, a combination of an antioxidant and an energy quencher is recommended. In this system, tensile and impact characteristics will decline

104

The Effects of UV Light and Weather on Plastics and Elastomers

to one-third the level of natural grade properties. 6. In either of the above cases (4 and 5), addition of 2–10 ppm of Monastral blue or violet (transparent pigment) will neutralize the observation of slightly yellow tints.

In applications where retention of “water white” clarity is necessary, elimination of the UV absorber component will reduce the yellow coloration. However, tensile properties will degrade to approximately 30% of the original. The use of a masking agent neutralizes the slight color due to the energy quencher.[65]

Table 17-1. Physical Properties and Visual Appearance after Florida and Arizona Outdoor Weathering for UV-Stabilized DuPont Surlyn® Ionomer

17: Ionomer

105

Table 17-2. Physical Properties and Visual Appearance after Accelerated Weathering in an Atlas Weatherometer for Zinc Ion Type UV-Stabilized DuPont Surlyn® Ionomer

106

The Effects of UV Light and Weather on Plastics and Elastomers

Table 17-3. Physical Properties and Visual Appearance after Accelerated Weathering in an Atlas Weatherometer for Zinc Ion Type UV- and Antioxidant-Stabilized, Pigmented DuPont Surlyn® Ionomer

17: Ionomer

107

Table 17-4. Physical Properties and Visual Appearance after Accelerated Weathering in an Atlas Weatherometer for Sodium IonType UV- and Antioxidant-Stabilized, Pigmented DuPont Surlyn® Ionomer

108

The Effects of UV Light and Weather on Plastics and Elastomers

Table 17-5. Physical Properties and Visual Appearance after Accelerated Weathering in a QUV Weatherometer for Zinc Ion Type DuPont Surlyn® Ionomer

Chapter 18

Polyphenylene Oxide Category: Polyphenylene ether (PPE)/polyphenylene oxide (PPO), polystyrene, thermoplastic. General Properties: GE Plastics Noryl® engineering thermoplastic resin is based on PPE (made and sold by GE Plastics under the trademark PPO). PPE, a high-heat amorphous polymer, forms a miscible, single-phase blend with polystyrene. This technology, in combination with other additives, provides a family of resins covering a wide range of physical and thermomechanical properties.[67]

Weathering Resistance PPO blends have good weathering resistance when adequately stabilized, but uncolored grades will yellow in UV light. Black grades have the best UV resistance.[68] Noryl® resins should not degrade, decompose, chalk, craze, or crack on exposure to outdoor weathering.[69] Noryl® resins will:[69] 1. Lose some impact and elongation (20–40%) strength depending on grade.

2. Gain tensile and flexural strength (5–15%) on long-term exposure. 3. Lose any surface gloss within a few months and become dull. 4. Change to a shade of color which is more yellow or darker on exposure. Only surface discoloration will occur. However, very thin sections (under 12.7 mm) may become more brittle. This brittleness occurs because the surface layers which are losing impact strength and becoming stiffer make up a proportionately larger volume of a thin section than a thicker section.[70] When exposed to outdoor light, parts of Noryl® resin undergo a color change with a tendency to darken slightly and drift toward yellow. When selecting Noryl® resins for outdoor use, dark colors— black and brown—are recommended, as well as reds, yellows, and oranges, which show excellent color stability and where the tendency to yellow is masked.[70]

110

The Effects of UV Light and Weather on Plastics and Elastomers

Table 18-1. Change in Yellowness Index and Percentage Gloss Retained after Outdoor Weathering Exposure in Arizona, Florida, and New York for GE Plastics Noryl® Modified PPO

Graph 18-1. Change in Color, E, after Accelerated Indoor UV Exposure of Modified PPO.

18: Polyphenylene Oxide

Graph 18-2. Dart Drop Impact Strength after Arizona Outdoor Weathering Exposure of Modified PPO.

Graph 18-3. Percentage Elongation after Arizona Outdoor Weathering Exposure of Modified PPO.

111

112

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 18-4. Tensile Strength after Arizona Outdoor Weathering Exposure of Modified PPO.

Graph 18-5. Change in Color, E, after Arizona Outdoor Weathering Exposure of Modified PPO.

18: Polyphenylene Oxide

Graph 18-6. Change in Color, E, after Ohio Outdoor Weathering Exposure of Modified PPO.

Graph 18-7. Dart Drop Impact Strength after Ohio Outdoor Weathering Exposure of Modified PPO.

113

Chapter 19

Nylon: Overview Category: Engineering resins, polyamide (PA). General Properties: Nylon is the common name for high-molecular weight PAs—semi-crystalline polymers typically produced by the condensation of a diacid and a diamine. There are several types of nylon; the numeric suffixes refer to the number of carbon atoms present in the molecular structures of the amine and acid, respectively, or a single suffix if the amine and acid groups are part of the same molecule. Nylons also differ structurally in the way the polymer chains are able to align and bond together. Amorphous grades of nylon are also available. The most widely used types are nylon 6 (PA6) and nylon 6,6 (PA6,6).

Weathering Properties: General Nylons are sensitive to UV radiation. Nylons find applications as engineering plastics as well as fiber materials. During normal use they are often exposed to sunlight, which causes extensive degradation of the polymer. Weatherability will be reduced unless UV stabilizers are incorporated into the formulation. Carbon black is the most commonly used UV stabilizer. Carbon black lowers the ductility and toughness as a trade-off for UV stability.[71]

Weathering Properties: UV Stabilization Honeywell offers a UV-stabilized nylon with a synergistic combination of additives—a reactive siloxane, a hindered amine, and a phosphite. This package offers a significant improvement in the UV stabilization of nylon resins. Nylon materials produced with this stabilizer system maintain their appearance upon weathering and are highly useful for a wide variety of structural and decorative articles.[72]

Weathering Properties: Colored Material Dyes are commonly used to add color to nylon. A key component of dye lightfastness is the type of dye chosen. Acidic and basic dyes react with the nylon molecule while disperse dyes are physically entrapped.

Chapter 20

Nylon 6 Category: Polyamide 6 (PA6). General Properties: BASF Ultramid® nylon 6 resins are high strength and stiffness molding compounds.

Weathering Properties Many Ultramid® resins are suitable for outdoor applications. The unreinforced stabilized Ultramid® resins (i.e., those with the letters K and H in the nomenclature type) are extremely resistant to weathering, even if they are uncolored. The outdoor performance can be further improved by the use of suitable pigments, the best effects being achieved with carbon black. For instance, seats that have been produced from Ultramid® B3K and B35K containing

special UV stabilizers and have been exposed for more than ten years in an open-air stadium have remained unbreakable, and their appearance has undergone hardly any change.[73] Thin articles for outdoor use should be produced from Ultramid® resins with a high carbon black content (e.g., the Black 20590 and 20592 types) to ensure that their strength remains undiminished. Moldings with a high proportion of carbon black can also withstand several years of exposure to tropical conditions.[73] Housings for automobile rear-view mirrors are examples of articles that must remain attractive for many years. In this type of application, the best results have been obtained with products containing special UV stabilizers and products with a high carbon black content (e.g., Ultramid® B35EG3 Black 20590).[73]

118

The Effects of UV Light and Weather on Plastics and Elastomers

Table 20-1. Mechanical Properties Retained after Outdoor Weathering Exposure in Florida for BASF Capron® Nylon 6

20: Nylon 6

119

Table 20-2. Mechanical Properties Retained after Outdoor Weathering Exposure in California and Pennsylvania for LNP Engineering Plastics® Nylon 6

Graph 20-1. Elongation at Break after Outdoor Exposure for Ube Ube® Nylon 6.

120

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 20-2. Flexural Modulus after Outdoor Exposure for Ube Ube® Nylon 6.

Graph 20-3. Notched Izod Impact Strength after Outdoor Exposure for Ube Ube® Nylon 6.

20: Nylon 6 Graph 20-4. Tensile Strength after Outdoor Exposure for Ube Ube® Nylon 6.

Graph 20-5. Flexural Strength at Break after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6.

121

122

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 20-6. Flexural Modulus after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6.

Graph 20-7. Notched Izod Impact Strength after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6.

20: Nylon 6 Graph 20-8. Weight Change after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6.

Graph 20-9. Flexural Strength after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6.

123

124

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 20-10. Tensile Strength after Outdoor Exposure in Hiratsuka, Japan, for Nylon 6.

Graph 20-11. Elongation after Sunshine Weatherometer Exposure of Nylon 6.

20: Nylon 6

Graph 20-12. Tensile Strength after Sunshine Weatherometer Exposure of Nylon 6.

125

Chapter 21

Nylon 12 Category: Polyamide 12 (PA12), thermoplastic. General Properties: EMS Grivory Grilamid® TR grades are transparent, thermoplastic polyamides based on aliphatic, cycloaliphatic, and aromatic blocks. Due to their composition, Grilamid TR grades combine the excellent properties of semicrystalline polyamide twelve types with those of an amorphous thermoplastic in a unique way.[79] •

Grilamid® TR 55

•

Grilamid® TR 55 LX

•

Grilamid® TR 55 LY is characterized by its good chemical and stress-crack resistance.

•

Grilamid® TR 90 is characterized by its extremely good UV resistance, high chemical and stress-crack resistance as well as high impact strength.

•

Grilamid® TR 90 UV is a water-clear transparent polyamide with outstanding weathering stability and excellent chemical resistance.

Weathering Properties Grilamid® TR 55 and TR 55 UV test plaques have been exposed for 40 months in southeast

Switzerland at 45◦ , facing south. Unstabilized Grilamid® TR 55 retained good transparency, but displayed some discoloration after 4 months of exposure and some brittleness after 25 months.[80] In contrast, Grilamid® TR 55 UV maintained its transparency with no brittleness, surface crazing or degradation, and no effect on relative viscosity. A small increase in yellowness occurred for up to eleven months of exposure and then showed no further increase. This compares very favorably with a typical stabilized polycarbonate in the same test, which showed significant loss of molecular weight and an increase in yellowness that seriously impaired transparency.[80] Samples of Grilamid® TR 55 and TR 55 UV were tested in an Atlas weatherometer, in cycles of 20 minutes (17 minutes of UV exposure followed by 3 minutes of UV exposure plus water spray). After 2000 hours, Grilamid® TR 55 UV showed no measurable change in color or surface appearance. In contrast, the unstabilized Grilamid® TR 55, while retaining transparency, showed an increase in yellowness and a slightly matte surface—a behavior similar to unstabilized polycarbonate.[80]

128

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 21-1. Change in Color, E, after Weatherometer Exposure of EMS Grilamid® TR 55, TR 55 LX, TR 90, and TR 90 UV Nylon 12 Compared to Other Polymers.[81] 20 PA 3-6-T TR 55 LX

∆E/1 mm

15

TR 55 PC UV

10

TR 90 TR 90 UV PA PACM12

5

PMMA 0 0

500

1000

1500

2000

2500

3000

Exposure Time (hrs)

Graph 21-2. Yellow Index (YI) after Weathering Exposure as per ASTM D1975 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX.[82] 25 TR 90 TR 90 UV

YI ASTM D1975

20

TR 55 LX TR 55

15 10 5 0 0

1000

2000

3000

4000

Exposure Time (hrs)

5000

6000

129

21: Nylon 12

Graph 21-3. Tensile Impact Strength after Weatherometer Exposure for EMS Grilamid® TR 55, TR 55 LX, and TR 55 LY Nylon 12.

Graph 21-4. Tensile Impact Strength after Weatherometer Exposure for EMS Grilamid® TR 90 and TR 90 UV Compared to Other Polymers.[81] 1000 TR 90 UV

2

Tensile Impact Strength (kJ/m )

TR 90 800 PA PACM12 PC UV 600

400

200

0 0

500

1000

1500

2000

Exposure Time (hrs)

2500

3000

130

The Effects of UV Light and Weather on Plastics and Elastomers

Half-Life Time (hrs)

Graph 21-5. Tensile Impact Strength Half-Life after Weathering for EMS Grilamid® TR 90, TR 90 LX, and TR 90 UV Compared to Other Polymers.[81] >2000

2000 1800 1600 1400 1200 1000 800 600 400 200 0 T

6-

PA

3-

TR

45

PC

G

V

PC

U

TR

90 TR

90

LX

V

12

M

PA

C PA

>2000

TR

90

U

A

M

PM

Graph 21-6. Yield Strength after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX.[82] 100 TR 90

90

TR 90 UV

Yield Strength (MPa)

80

TR 55 LX 70 TR 55 60 50 40 30 20 10 0 0

1000

2000

3000

4000

5000

6000

7000

8000

Exposure Time (hrs)

Graph 21-7. Percentage Retention of Yield Strength after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX.[82] 120

TR 90 TR 90 UV

100

Yield Strength (%)

TR 55 LX TR 55

80 60 40 20 0 0

1000

2000

3000

4000

5000

Exposure Time (hrs)

6000

7000

8000

131

21: Nylon 12

Graph 21-8. Percentage Retention of Elongation at Break after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, TR 55, and TR 55 LX.[82] 140 TR 90 TR 90 UV

Elongation at Break (%)

120

TR 55 LX 100

TR 55

80 60 40 20 0 0

1000

2000

3000

4000

5000

6000

7000

8000

Exposure Time (hrs)

Graph 21-9. Percentage Retention of Work to Break after Weathering Exposure as per ISO 4892-2 for EMS Grilamid® TR 90, TR 90 UV, and TR 55 LX.[82]

Work to Break (%)

180

TR 90

160

TR 90 UV

140

TR 55 LX

120 100 80 60 40 20 0 0

1000

2000

3000

4000

5000

Exposure Time (hrs)

6000

7000

8000

132

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 21-10. Transparency of EMS Grilamid® and EMS Grivory® Compared to Glass and Other Polymers.[81] 100 90

90

91

89

Transparency (%) 540 nm, 3 mm

90

90

89

87

85

80 70 60

G la ss

PS

A

G riv or

y

PM

M

PC

45 G TR

LX 70 TR id

id G ril am

G ril am

G ril am

id

TR

TR

55

90

50

Graph 21-11. Transparency in the Visible Spectrum of EMS Grilamid® Compared to Other Polymers.[81] 100

Transmission (%)

80

60

40

20

0 200

250

300

350

400

450

500

550

600

650

700

Wavelength (nm) TR 55

TR 90

Note: Spectrometer LAMBDA 19 UV/VIS/NIR, thickness 2 mm.

PMMA

PC

750

800

Chapter 22

Nylon with Glass Fiber Category: Polyamide with glass fiber reinforcement.

General Properties: Glass fibers can be added to increase the stiffness of nylon. Because material properties such as elongation and impact strength can be adversely impacted by the addition of glass fibers, a toughener is often included in the product formulation to retain initial elongation and impact strength. Fiberglass reinforcement improves the strength, stiffness, dimensional stability, and performance at elevated temperatures of BASF’s Ultramid® nylon. Reinforcement levels of the different grades range from 6% to 63%.

Weathering Properties The reinforced Ultramid® resins also give good outdoor performance, and the stabilized types (e.g., Ultramid® B3EG5) can be relied upon to withstand exposure for periods greater than 5 years. Nevertheless, the constituent glass fibers cause the surface to be attacked more severely than that of unreinforced Ultramid® articles.As a consequence, the texture and the hue may undergo a change after comparatively brief exposure periods. If the glass-reinforced moldings remain exposed for a number of years, erosion to a depth of a few tenths of a millimeter (0.04 in.) can generally be expected, but experience has shown that this does not exert any significant effect on the mechanical properties.[73]

Table 22-1. Material Properties Retained after Outdoor Weathering in California and Pennsylvania for LNP (a Division of GE Plastics) Glass-Reinforced Nylon 610

Chapter 23

Nylon 66 Category: Polyamide 66 (PA66) thermoplastic. General Properties: DuPont Zytel® nylon 66 polymer family is available in glass, mineral, super tough, or unreinforced grades. Zytel® 101 is a general purpose unreinforced PA66.

Weathering Properties Nylon 66 degrades upon exposure to natural and artificial weathering. This degradation causes changes in its chemical, physical, and mechanical properties. The degree of changes depends on the wavelength of the UV radiation and the atmospheric conditions. Chromophores∗ , defects, and impurities initiate the hydroperoxidation∗∗ when nylon polymers are exposed to light of higher wavelength (λ = 340 nm), whereas at lower wavelength (λ = 254 nm) exposure, direct photoscission occurs, which is independent of the length of the carbon chain.[84] Neat (not dyed, not bonded, not stabilized) nylon 66 tops the chart for strength retention after nine months of exposure in Florida. When natural colored fibers were tested for nine months of exposure

∗ Chromophore

is the light absorbing part of a photopigment. Many natural pigments are based on the quinone chromophore. The ability of a compound to absorb light depends on the presence of certain kinds of structural features (i.e., chromophores). ∗∗ Hydroperoxidation is the decay of the hydroperoxide radical (R–C–O–O• ).

in Florida sunlight, the DuPont type 66-728 nylon showed the highest percentage of strength retention when compared to nylon 6, polyester, and polypropylene. The resistance to UV exposure and weathering increases substantially as UV stabilizers, dyestuffs, and bonding agents are added in the manufacturing process. Starting with the right raw material is crucial in obtaining long life and durability.[85]

Weathering Properties: Colored Material Nylon 66 is relatively resistant to fading due to sunlight or atmospheric conditions. Nylon 66 is often dyed to provide color. A key component of dye lightfastness is the type of dye chosen. The dye diffusion rate for nylon 66 is relatively slow. However, it is difficult to remove dye from the finished product. Nylon 66 is therefore a relatively lightfast nylon. Nylon 66 is also resilient to the diffusion of other molecules through the fiber, like ozone and nitrous oxide, which can harm the fiber or dye.[85]

Chapter 24

Nylon 6,6T Category: Polyamide 6,6, thermoplastic, partly aromatic polyamide. General Properties: BASF Ultramid® 6/6T is a semi-crystalline, semi-aromatic nylon 6/6T or 6,6T.

Weathering Properties The experience gained in the outdoor performance of Ultramid® A and B applies essentially to

Ultramid® T. However, Ultramid® T is degraded and discolored somewhat more rapidly than nylon 66 and nylon 6 when exposed to prolonged UV radiation.[86]

Chapter 25

Nylon MXD6 Category: Aliphatic polyamide. General Properties: Nylon MXD6 is a crystalline polyamide resin developed by Mitsubishi Gas Chemical Company, Inc, which is produced through the polycondensation of meta-xylene diamine (MXDA) with adipic acid.

Graph 25-1. Flexural Modulus after Outdoor Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon.

140

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 25-2. Notched Izod Impact Strength after Outdoor Weathering Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon.

Graph 25-3. Flexural Strength after Outdoor Weathering Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon.

25: Nylon MXD6

141

Graph 25-4. Tensile Strength after Outdoor Weathering Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon.

Graph 25-5. Elongation (%) after Sunshine Weatherometer Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon.

142

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 25-6. Tensile Strength after Sunshine Weatherometer Exposure in Hiratsuka, Japan, for Mitsubishi Reny® MXD6 Nylon.

Chapter 26

Polyarylamide Category: Filled/reinforced thermoplastic, polyarylamide. General Properties: Solvay Advanced Polymers IXEF® compounds are a family of semi-crystalline polyarylamide thermoplastics reinforced with glass fibers. IXEF® 1002 contains 30% glass fiber, while IXEF® 1022 contains 50% glass fiber.

Weathering Properties Specimens of IXEF® 1002 and IXEF® 1011 were exposed to the weather for four years at the Hiratsuka Test Station under the following conditions: average temperature 23◦ C, extremes 0◦ C and 30◦ C; average precipitation = 130 mm per month, extremes 50–200 mm per month; total solar irradiance 500 kJ/cm2 per year.[77] The results obtained on the 3.2 mm specimens showed: 1. Water absorption of approximately 0.8%. 2. An approximate 30% reduction in the maximum stress, essentially corresponding to the reversible plasticization brought about by water. 3. No change in flexural modulus.

The surface of a part made from IXEF® product is a layer of pure polymer approximately 1 µm thick. This layer allows a very good gloss finish to be obtained. If photo-oxidation occurs, this layer deteriorates as a result of a change in the roughness of the surface (e.g., an increase from Ra = 0.15 µm to Ra = 2 µm). If a very small quantity of material (3 mg/m2 ) undergoes oxidation, it results in a change in the appearance of the surface (gloss and color) without the other properties of the material being affected in any way.[77] When choosing the surface appearance of parts likely to be exposed to UV, it is advisable to avoid excessively low roughness levels because they will be affected to a considerable degree by superficial photo-oxidation.[77] To date, experience with outdoor IXEF applications has established that the variations in shades observed are acceptable for many colors. Some particularly exacting sectors of the market have very stringent requirements; special IXEF grades may satisfy these requirements in certain cases.[77] Flame-resistant grades exhibit variations in shade that are generally unacceptable for light colors.[77]

144

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 26-1. Flexural Strength after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022.

Graph 26-2. Flexural Modulus after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022.

26: Polyarylamide

145

Graph 26-3. Notched Izod Impact Strength after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022.

Graph 26-4. Weight Change after Outdoor Exposure in Hiratsuka, Japan, for Solvay IXEF® 1002 and IXEF® 1022.

Chapter 27

Polycarbonate Category: Thermoplastic. General Properties: Polycarbonate (PC) is an amorphous thermoplastic with excellent toughness characteristics, clarity, and heat deflection properties. With the appropriate UV stabilization, PC can be used in products ranging from automotive parts to sunglasses.[87] •

GE Plastics Lexan® resin is a ‘water white’ material that is naturally transparent. It demonstrates light transparency close to that of glass and has a very high refractive index.

•

GE Plastics Lexan® SLX resin is a copolymer that has been derived from polyester carbonates and resorcinol arylates. When exposed to UV light, the copolymer undergoes a photoFries rearrangement and produces a new structure that is inherently a UV screener, essentially making the resin self-protecting.

•

Dow Calibre® resins are available with (outdoor applications) and without (indoor applications) UV stabilization packages.

Weathering Properties PC is used in building applications, mainly as glazing material. “When irradiated with short wavelength UV-B or UV-C radiation, polycarbonates undergo a rearrangement reaction (referred to as photo-Fries rearrangement). At low oxygen levels this reaction can yield yellow-colored products such as o-dihydroxy-benzophenones. But when irradiated at longer wavelengths (including solar visible

wavelengths) in the presence of air, polycarbonates undergo oxidative reactions that result in the formation of other yellow products. However, neither the detailed mechanisms nor the specific compounds responsible for the yellow coloration have been fully identified. Monochromatic exposure experiments on the wavelength sensitivity of several degradation processes of bis-phenol A polycarbonates have been reported recently.”[5] Lexan® resin may be sensitive to long-term exposure to UV light and weathering. The degree of sensitivity is very much dependent on the specific grade, the specified color, and the weathering conditions. Lexan® resin is ideally suited to a range of both indoor and outdoor applications. UV-stabilized Lexan® resin grades maintain high light transmission after prolonged UV exposure and offer good resistance to yellowing after prolonged exposure to harsh climatic conditions.[88] Lexan® resin can be additionally protected for applications in which they are exposed to critical environments of intense sunlight and high humidity. Tailor-made, glass clear, UV cap layers further improve the weathering resistance of extruded Lexan® sheet. For injection-molded parts a variety of coatings, including a range of GE Silicone hardcoats, enhance weathering, scratch, and abrasion resistance.[88] Lexan® SLX injection-molding grades, which are transparent, demonstrate (in laboratory testing) excellent weathering (more than seven years), high light transmission (>83%), and low haze (<1%), with performance and processing much like standard PC. Depending upon conditions, the SLX materials offer five to ten times better gloss, color, and light transmission retention than standard UV-stabilized PC. After a slight initial color shift, the transparent grades of Lexan® SLX resin offer a longer lifetime of UV stability and clarity than traditional UV-stabilized PC.[89]

148

The Effects of UV Light and Weather on Plastics and Elastomers Lexan® 143R-111 and Lexan® LS2-111 have a builtin UV screen to filter out UV radiation up to 380 nm. Modified grades such as Lexan® OQ4320 resin will filter UV radiation up to 400 nm, thereby providing additional sun protection without affecting the transmission in the visible region. Special colors provide a high light transmission in the infrared region only, which blocks all light in the visible light region for applications such as remote control panels.[88]

One of GE’s most weatherable products is Lexan® EXL resin, a copolymer of PC and silicone. This material demonstrates excellent retention of mechanical properties upon outdoor exposure.[90] Calibre® resins without UV stabilizers pass the accelerated indoor colorfast tests described by ASTM D4459, which simulate a three- to fiveyear exposure in an indoor office environment. For Calibre® resins tested under these conditions, the change in color as measured by E is typically less than two units.[91] For outdoor environments, Calibre® resins are available with enhanced weathering resistance. These resins are designated by a 2 or 3 in the last digit of the product identification code (e.g., 302 15 MFR or 703 15 MFR). The UV-stabilized formulations can greatly extend retention of the key physical properties.[91]

Weathering Properties: UV Stabilization Tinuvin® 234, a benzotriazole UV absorber, is well adapted to the UV stabilization of PC due to its low volatility, good initial color, and compatibility with PC. To achieve the highest possible resistance to fading and weathering, Tinuvin® 1577, a UV absorber, may be used. This product is particularly recommended for use in coextruded PC sheets.[87]

Light Transmission The light transmission of transparent Lexan® resin can be changed if required. Grades such as

Weathering Properties by Material Supplier Trade Name Table 27-1. Izod Impact and Surface and Appearance Properties after Arizona Outdoor Exposure of Dow Calibre® 300 6 MFR without and with UV Stabilizer Material Family

Polycarbonate

Material Grade

Dow Calibre® 300 6 MFR

Reference Number

91 Arizona, 45◦ angle facing south

Exposure Conditions Exposure Time

2 years

Features Time

Without UV Stabilizer

With UV Stabilizer

0

6 months

1 year

2 years

0

6 months

1 year

2 years

17.6

17.9

1.2

0.6

18.2

17.9

17.7

18.5

Transmittance (%)

89.4

85.8

84.7

82.3

89.6

88.4

88.5

87.3

Haze (%)

1.7

8.2

12.7

19.8

1.6

6.8

9.0

14.8

0

+12.3

+15.7

+20.0

0

+2.3

+3.3

+6.1

MECHANICAL PROPERTIES Izod Impact (ft-lb/in.) SURFACE AND APPEARANCE

Yellowness Index Increase

27: Polycarbonate

149

Table 27-2. Mechanical Properties Retained after California and Pennsylvania Outdoor Exposure of LNP Engineering Plastics PC

150

The Effects of UV Light and Weather on Plastics and Elastomers

Table 27-3. Mechanical Properties and Surface and Appearance Properties after Arizona Accelerated Outdoor Weathering and Kentucky Outdoor Weathering for GE Lexan® S-100 and Lexan® 100 Sheet

27: Polycarbonate Table 27-4. Mechanical Properties Retained after XW Accelerated Weathering for GE Lexan® 303

Table 27-5. Change in Color, E, after Accelerated Indoor Exposure of GE Lexan® 920A by HPUV

151

152

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 27-1. Light Transmission of UV-Stabilized GE Plastics Lexan® .[88] UV

100

Visible

Infrared 280–315 nm UV-B–middle UV region 315–380 nm UV-A–middle UV region 380–780 nm visible light region 780–1400 nm near infrared region 1400–3000 nm middle infrared region

Light Transmission (%)

80

60

40

20

0

0

800

1600

2400

3200

Wavelength (nm)

Graph 27-2. Light Transmission of Transparent GE Plastics Lexan® .[88]

100

UV

Visible

Infrared

Light Transmission (%)

141R non-UV stabilized 80

LS2 UV stabilized

60

OQ4320 UV stabilized with 400 nm cutoff 121R “infrared” color

40

20

0 300

400

500

600

700

800

Wavelength (nm)

900

1000

1100

153

27: Polycarbonate

Graph 27-3. Transmittance through Transparent GE Plastics Lexan® after Florida Outdoor Exposure as per ASTM G7.[88]

Transmittance (%)

90

UV stabilized nonstabilized

80

70

60

50 0

1

2

3

4

5

Exposure (years)

Graph 27-4. Yellowness Index after Florida Outdoor Exposure as per ASTM G7 for GE Plastics Lexan® .[88]

Yellowness Index

40

UV stabilized nonstabilized

30

20

10

0 0

1

2

3

4

5

Exposure (years)

Graph 27-5. Haze after Accelerated Outdoor Exposure of Coated and Uncoated Transparent GE Plastics Lexan® .[88]

Haze (%)

15

Uncoated coated

10

5

0

0

500

1000

Exposure (years)

1500

2000

154

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 27-6. Yellowness Index after Accelerated Outdoor Exposure of Coated and Uncoated Transparent GE Plastics Lexan® .[88]

Yellowness Index

15

Uncoated coated

10

5

0

0

500

1000

1500

2000

Exposure (years)

Graph 27-7. Yellowness Index after Xenon Arc Weathering for GE Plastics Lexan® .[88]

Yellowness Index

10

UV stable PC Lexan SLX2431 resin

8

6 4 2

0

0

1000 2000 3000 4000 5000 6000 7000 8000 9000

Exposure (kJ/m2)

Graph 27-8. Change in Yellowness Index, YI, after Whirlygig Accelerated Outdoor Exposure of GE Plastics Lexan® .[88] 40

UV stable PC Lexan SLX2431 resin

36 32 28

∆YI

24 20 16 12 8 4 0 0

1000 2000 3000 4000 5000 6000 7000 8000 9000

Exposure (hrs)

27: Polycarbonate

155

Graph 27-9. Yellowness Index after Kentucky Outdoor Weathering for GE Lexan® S-100 Sheet.

Graph 27-10. Yellowness Index after EMMAQUA Accelerated Arizona Weathering for GE Lexan® S-100 Sheet.

156

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 27-11. Haze (%) after Carbon Arc XW Weathering for GE Lexan® 153.

Graph 27-12. Yellowness Index after Twin Carbon Arc Weathering for GE Lexan® S-100 Sheet.

157

27: Polycarbonate

Graph 27-13. Yellowness Index after Outdoor Weathering for PC Natural and UV Stabilized with Tinuvin® 234 Benzotriazole UV Absorber.[87]

Control

Yellowness Index

30

20 + 0.3% Tinuvin 234

10

0 0

50

100

150

200

250

300

Exposure (kLy) Note: ISO 4607, Florida; 2 mm injection-molded plaques.

Graph 27-14. Gloss (20◦ ) Retention after Xenon Arc Weathering of Twin Wall PC Sheets (10 mm) Stabilized with Tinuvin® UV Absorbers.[87]

120

Gloss

3.5% Tinuvin 1577

80

3.5% Tinuvin 360 40

Control 0

0

2000

4000

6000

8000

Exposure time (hours) Note: Xenon Arc Weathering, ISO 4892-2, Cycle 102/18; 40 µm coextruded film.

10000

Chapter 28

Polycarbonate Blends Category: Thermoplastic alloys. General Description: Polycarbonate (PC) is frequently blended with polyesters (polyethylene terephthalate and polybutylene terephthalate) and styrenics (acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-acrylate) to modify its properties for a great variety of end uses.[87] GE Plastics Cycoloy® resins are amorphous PC/ABS blends.

Weathering Properties: Stabilization Tinuvin® 234 protects PC blends from the discoloration associated with exposure to UV light. As shown in Graph 28-3, it takes much longer for the sample containing Tinuvin® 234 to reach the same level of discoloration as the control sample.[87]

Weathering Properties Cycoloy® resins exhibit excellent UV stability. Slight color change and loss of mechanical properties can result after long-term exposure.[94]

Weathering Properties by Material Supplier Trade Name Graph 28-1. Color Change, E, of Pigmented GE Plastics Cycoloy® C1100 PC/ABS after Accelerated UV Exposure as per SAE J1885 (ATLAS Ci65XW) and DIN75202 (XENON450).[94] 8 Ultramarine Blue SAE J1885 DIN75202

7 6

Medium Gray SAE J1885 DIN75202

∆E

5 4

Dark Gray SAE J1885 DIN75202

3 2 1 0 0

50

100

150

200

Exposure Time (hrs)

250

300

160

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 28-2. Color Change, E, of Pigmented GE Plastics Cycoloy® C1100 PC/ABS after Accelerated UV Exposure as per SAE J1885 (ATLAS Ci65XW) and DIN75202 (XENON450).[94]

Color Change (∆E or gray scale)

8 Black/gray scale SAE J1960 DIN53387

7 6

Black/∆E SAE J1960 DIN53387

5 4 3 2 1 0

400

0

800

1200

1600

Exposure Time (hrs)

Graph 28-3. Color Development after Xenon Arc Weatherometer Exposure of PC/ABS (50/50) Blend with Tinuvin® 234 UV Stabilizer.[87] Xenon Arc Weathering, ISO 4892-2, Cycle 102/18

Control

+ 0.5% Tinuvin 234

0

500

1000

Exposure Time to ∆YI = 5 (hrs)

1500

Chapter 29

Polybutylene Terephthalate Category: Thermoplastic polyester. General Properties: Polybutylene terephthalate (PBT) is a semi-crystalline polyester that provides a good combination of stiffness and toughness and can withstand continuous service at 120◦ C. The most important grades are those reinforced with glass. •

BASF Ultradur®

•

Ticona Celanex® PBT is a series of semi-crystalline thermoplastic polyesters based on PBT.[95]

Weathering Properties PBT end-products suffer from cracking, yellowing, loss of gloss, and deterioration of tensile impact properties when exposed to UV light.[96] Moldings made from Ultradur® and exposed to three years of open air weathering in central Europe tend to discolor very slightly and their surface scarcely changes. Mechanical properties such as rigidity, tensile strength, and tear strength are slightly affected. After a weathering test for 3600 hours in the Xenotest® 1200, the tensile strength retained is 90%

of the initial value. However, elongation at break is more adversely affected. Based on experience, 3600 hours in the Xenotest® 1200 equipment corresponds to about five to six years of weathering in open air. Parts for outdoor use should be manufactured from black-colored material in order to prevent impairment of strength due to surface attack. Fiber-reinforced PBT grades such as Ultradur® B 4040 G4/G6/G10 with outstanding surface quality and high resistance to UV radiation are suitable for parts that are subject to particularly extreme exposure. These grades have outstanding surface quality and exhibit high resistance to UV radiation.[97] Results taken after three years of outdoor exposure indicate that there is no fundamental change in physical properties. Predictably, black Celanex® 3300 polyester resin exhibits better property retention than natural resins and should therefore be considered where long-term outdoor exposure is required.[98]

Weathering Properties: Stabilization Ciba Tinuvin® 234 and Tinuvin® 1577 can offer PBT products high-quality UV protection.[96]

162

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Graph 29-1. Notched Izod Impact Strength after Florida and Arizona Outdoor Weathering for Ticona Celanex® PBT.

Graph 29-2. Tensile Strength after Florida and Arizona Outdoor Weathering for Ticona Celanex® PBT.

29: Polybutylene Terephthalate

Graph 29-3. Flexural Strength at Break after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester.

Graph 29-4. Flexural Modulus after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester.

163

164

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 29-5. Notched Izod Impact Strength after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester.

Graph 29-6. Weight Change after Hiratsuka, Japan, Outdoor Exposure of PBT Polyester.

165

29: Polybutylene Terephthalate Graph 29-7. Tensile Strength Retained after Weatherometer Exposure of Ticona Celanex® PBT.

Graph 29-8. Change in Yellowness Index, YI, after Light Exposure of PBT Injection-Molded Plaques.[96] 50 Control 40

∆YI

30

0.05% Tinuvin 234

20

10 0.05% Tinuvin1577 5

0

0

2000

4000

6000

8000

10000

Exposure Time (hrs) Note: Xenon Arc Weathering, ISO 4892-2, Cycle 102/18; 1 mm plaques; base stabilization: 0.10% Irganox® 1010 and 0.40% Irgafos® 168 (Irganox® B 561).

Chapter 30

Polyethylene Terephthalate Category: Thermoplastic, polyester. General Description: Polyethylene terephthalate (PET) can be transparent in the amorphous state or translucent in the semi-crystalline state. PET, also called polyester, refers to any one of a large family of synthetic polymers composed of at least 85% by weight of an ester of a substituted aromatic carboxylic acid. DuPont Rynite® PET thermoplastic polyester resins contain uniformly dispersed glass fibers or mineral/glass fiber combinations in PET resin that has been specially formulated for rapid crystallization during injection molding.[100] •

Rynite® 530 contains 30% glassreinforced modified PET

•

Rynite® 545 contains 45% glassreinforced modified PET

•

Rynite® 935 contains 35% mica/glassreinforced modified PET

Weathering Properties Rynite® 530 NC10 and BK503 and Rynite® 545 NC10 and BK504 resins have been exposed outdoors in Florida and Arizona facing 45◦ south for

three years. The data for these samples indicate that the resins have retained over 72% of their initial tensile strength and over 50% of their initial elongation. The compositions containing carbon black had higher property retention. After three years, all the test samples were slightly “etched.”[101] After 500,000 langleys of exposure in the equatorial mount with mirrors (EMMA) and EMMA with water spray (EMMAQUA) environments, Rynite® 530 NC10 and BK503 and Rynite® 545 NC10 and BK504 resins maintained over 90% of their original tensile strength and 73% of their original elongation properties. The EMMA and EMMAQUA environments have similar effects on the properties of the Rynite® 530 and Rynite® 545 resins. All test specimens had reduced gloss levels after exposure. On an average, samples exposed in Arizona received approximately 150,000 langleys of sunlight per year. These tests correspond to about 3.3 years of natural weathering in Arizona.[101]

168

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 30-1. Tensile Strength and Elongation Retained after Arizona Outdoor Weathering of DuPont Rynite® 545 NC10, Rynite® 545 BK504, and Rynite® 935 BK505

30: Polyethylene Terephthalate

169

Table 30-2. Tensile Strength and Elongation Retained after Arizona Outdoor Weathering of DuPont Rynite® 530 NC10 and Rynite® 530 BK503

Table 30-3. Tensile Strength and Elongation Retained after Florida Outdoor Weathering of DuPont Rynite® 530 NC10 and Rynite® 530 BK503

170

The Effects of UV Light and Weather on Plastics and Elastomers

Table 30-4. Tensile Strength and Elongation Retained after Florida Outdoor Weathering of DuPont Rynite® 545 NC10 and Rynite® 545 BK504

30: Polyethylene Terephthalate

171

Table 30-5. Tensile Strength and Elongation Retained after Arizona EMMA and EMMAQUA Weathering of DuPont Rynite® 530 NC10, Rynite® 530 BK503, Rynite® 545 NC10, and Rynite® 545 BK504

Graph 30-1. Tensile Strength after Sunshine Weatherometer Exposure of PET.

172

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 30-2. Elongation after Sunshine Weatherometer Exposure of PET.

Chapter 31

Liquid Crystal Polymers Category: Thermoplastic. General Properties: Liquid crystal polymers (LCPs) are a unique class of wholly aromatic polyester polymers that provide high-performance properties.[102] •

Ticona Vectra® LCPs are highly crystalline, thermotropic (melt-orienting) thermoplastics

Weathering Properties LCP resins exhibit excellent mechanical property retention after exposure to weathering.[102]

After 2000 hours of artificial weathering, moldings made from Vectra® retained more than 90% of their initial mechanical property values. After one year of outdoor weathering, a slight white deposit was detected. The white deposit is the degraded material that appears on the surface (chalking) and results in a reduction in gloss, color change, and deterioration of mechanical properties.[103]

174

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 31-1. Mechanical Properties Retained after Xenon Arc Accelerated Weathering for Ticona Vectra® A950, Vectra® A130, Vectra® B950, and Vectra® A540

Chapter 32

Polyarylate Category: Thermoplastic. General Properties: Westlake Ardel® is a transparent thermoplastic with a slight yellow tint.

Weathering Properties Ardel® resins are specifically formulated to endure the damaging effects of UV light. When exposed to UV light, this unique material undergoes

molecular rearrangement resulting in the formation of a protective layer that essentially serves as a UV stabilizer. This inherent UV stability combined with superior retention of optical and mechanical properties makes polyarylate an ideal choice for any application where weathering effects could pose a problem.[104]

Chapter 33

Polyimide Category: Thermoset. General Properties: DuPont Kapton® is synthesized by polymerizing an aromatic dianhydride with an aromatic diamine. UBE Upilex® R is produced by the polycondensation of biphenyltetracarboxylic dianhydride and diamine and is meant for general use.

in an Atlas weatherometer. Normal room fluorescent lighting has no noticeable degrading effect on Kapton® .[1] UBE Upimol® R is stable when exposed to sunshine and UV light.[105]

Weathering Properties: Outer Space and Nuclear Environments

Weathering Properties: General UV radiation, oxygen, and water have a degrading effect on Kapton® if it is directly exposed. This effect is shown as a loss of elongation when Kapton® is exposed in Florida test panels. Kapton® also shows a loss of elongation as a function of exposure time

Because of its excellent radiation resistance, Kapton® is frequently used in high radiation environments where a thin, flexible insulating material is required. US Government and CERN (European Organization for Nuclear Research) data are available from the manufacturer of this product.[1]

Weathering Properties by Material Supplier Trade Name

Ultimate Elongation (%)

Graph 33-1. Ultimate Elongation after Florida Aging of DuPont Kapton® Film.[1] 120 100 80 60 40 20 0

500

1000

1500

2000

2500

3000

Exposure Time (hrs)

3500

4000

4500

5000

178

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 33-2. Ultimate Elongation after Atlas Weatherometer Exposure of DuPont Kapton® .[1]

Ultimate Elongation (%)

120 100 80 60 40 20 0

0

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

Exposure Time (hrs)

Graph 33-3. Elongation Retained after Sunshine Weatherometer Exposure for UBE Upilex® R and UBE Upilex® S.

33: Polyimide

179

Graph 33-4. Flexural Strength Retained after Sunshine Weatherometer Exposure for UBE Upimol® R.

Graph 33-5. Tensile Strength Retained after Sunshine Weatherometer Exposure for UBE Upilex® R and UBE Upilex® S.

180

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 33-6. Flexural Strength Retained after UV-CON Exposure for UBE Upimol® R.

Chapter 34

Polyamideimide Category: Thermoplastic, engineering resin. General Properties: Solvay Advanced Polymers Torlon® 4203L polyamideimide resin is an unreinforced, all-purpose grade, which contains 3% titanium dioxide and 0.5% fluoropolymer.[107]

resin does not degrade after 6000 hours of weatherometer exposure, which is roughly equivalent to five years of outdoor exposure. The bearing grades, such as 4301, contain graphite powder that renders the material black and screens UV radiation. These grades are even more resistant to degradation due to outdoor exposure.[107]

Weathering Properties Torlon® molding polymers are exceptionally resistant to degradation by UV light. Torlon® 4203L

Weathering Properties by Material Supplier Trade Name Graph 34-1. Elongation after Atlas Sunshine Carbon Arc Weatherometer Exposure for Torlon® 4203L.[107] 14.0 12.0

4203L

Elongation (%)

10.0 8.0 6.0 4.0 2.0 0.0 10

100

1000

10000

Exposure Time (hrs) Note: The test conditions included a black panel temperature of 145◦ F (63◦ C), 50% relative humidity, and an 18-minute water spray every 102 minutes.

182

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 34-2. Tensile Strength after Atlas Sunshine Carbon Arc Weatherometer Exposure for Torlon® 4203L.[107] 30

200

4203L

150 20

15

100

10 50

Tensile Strength (MPa)

Tensile Strength (kpsi)

25

5 0 10

100

1000

0 10000

Exposure Time (hours) Note: The test conditions included a black panel temperature of 145◦ F (63◦ C), 50% relative humidity, and an 18-minute water spray every 102 minutes.

Chapter 35

Polyetherimide Category: Thermoplastic.

Weathering Properties

General Properties: GE Plastics Ultem® 1000 polyetherimide is an amorphous, translucent engineering thermoplastic with good rigidity and thermal mechanical strength for demanding applications.[108]

Ultem® resin is inherently resistant to UV radiation without the addition of stabilizers. Exposure to 1000 hours of xenon arc weatherometer irradiation (0.35 W/m2 irradiance at 63◦ C) produces a negligible change in the tensile strength of the resin.[108]

Weathering Properties by Material Supplier Trade Name Graph 35-1. Tensile Strength after Xenon Arc Weatherometer Exposure of GE Plastics Ultem® 1000.

Chapter 36

Polyetheretherketone (PEEK) Category: Polyketone, thermoplastic.

Weathering Properties

General Properties: PEEK, a unique semicrystalline, high-temperature engineering thermoplastic, is an excellent material for a wide spectrum of applications where thermal, chemical, and combustion properties are critical to performance. The addition of glass fiber and carbon fiber reinforcements enhances the mechanical and thermal properties of the basic PEEK material.

Victrex® PEEK, like most linear polyaromatics, suffers from the effects of UV degradation during outdoor weathering. However, testing has shown this effect to be minimal over a twelve-month period for both natural and pigmented moldings. In more extreme weathering conditions, painting or pigmenting will protect the polymer from excessive property degradation.[110]

Table 36-1. Tensile Strength Retained after United Kingdom Outdoor Weathering Exposure of Natural, Black, and White Pigmented Victrex® PEEK

186

The Effects of UV Light and Weather on Plastics and Elastomers

Table 36-2. Tensile Strength Retained after United Kingdom Outdoor Weathering Exposure of Pigmented Victrex® PEEK

Chapter 37

Polyethylene: Overview General Properties: Polyolefin homopolymers are made from ethylene, propylene, butylene, and methyl pentene. Other olefin monomers such as pentene and hexene are used to make copolymers. The principal resins of the polyolefin family are polyethylene and polypropylene, and polyolefin copolymers such as ethylene-vinyl acetate, ionomer, polybutylene, and polymethyl pentene.[111]

Weathering Properties: General All polyethylene (and polypropylene) resins are susceptible to degradation upon long-term exposure to sunlight, thereby losing useful tensile properties. Polyethylene films exposed to solar UV-B radiation readily lose their tensile strength as well as their average molecular weight. The mechanism causing this deterioration is one of “thermooxidative or photooxidative degradation rather than of direct photolysis, and is catalyzed by the presence of metal compounds.” The free radical pathways lead to hydroperoxidation and consequent chain scission.[5] UV light contains shorter wavelengths than visible light. The shorter the wavelength, the more energy it contains and thus the more damage it does. Fluorescent lighting also contains a band of UV light, but only at an intensity of around 15% of normal sunlight.[112] Generally, higher density resins, which are composed of a larger crystal structure and have less potential for entrapping oxygen, provide better UV stability. Although the secondary effect of a lower melt index (MI), which provides a tougher part and thus longer life to obtain the same absolute break point, is a factor, the MI does not directly affect UV stability. Thus, all things being equal, higher density and lower MI polyethylenes enhance UV performance. Again these factors are generally negligible.[112]

UV light alters the molecular characteristics of polyethylene by breaking the carbon-hydrogen bonds and creating free radicals. The free radicals then break polyethylene into shorter molecules resulting in a more brittle polymer. UV light creates a higher MI polyethylene, especially on the exposed surface area. Degradation can range from mere surface discoloration affecting the aesthetic appeal of a product to extensive loss of mechanical properties that severely limits its performance. This shows up as a reduction in break elongation and impact properties, typical of higher MI polyethylene. The subsequent attachment of oxygen to these broken sites leads to further accelerated degradation and the formation of oxidized species such as carbonyl and carboxyl structures, which are often used as analytical indicators of UV degradation.[112]

Polyethylene Films The crucial role of temperature on the weathering of polyethylenes was illustrated in a recent study on desert exposure of polyethylene films.[112] Two sets of polyethylene film samples, one maintained at 25◦ C at all times in an air-cooled, UV-transparent enclosure, and the other left under the much higher ambient temperature, were exposed to sunlight outdoors. The air temperature varied in the range 26◦ C– 36◦ C during the period of exposure. However, the surface temperature of plastics exposed to sunlight was much higher (by as much as 60◦ C for common plastics depending on the color and the thickness) than that of the surrounding air due to heat buildup. Samples kept at the lower temperature deteriorated much slower than those at ambient temperature although both were exposed to the same dose of solar UV radiation. It is the synergistic effect of high temperature and solar UV radiation that is responsible for the rapid degradation of polyethylene films under these conditions. The findings are consistent with the

188

The Effects of UV Light and Weather on Plastics and Elastomers

observation that weathering rates of common plastics are very much slower when exposed floating in sea water, in marine environments, compared to those exposed on land. Water acting as a heat sink is able to maintain low sample temperatures, retarding deterioration.[112]

Weathering Properties: Color Pigments Polyethylene is often colored or pigmented. The choice of pigment can determine the outdoor performance of the polyethylene product. The amount, particle size, and chemical type of pigment, such as its organic or inorganic nature, can all affect the UV performance. Generally, carbon black tends to be the best UV performer due to its high absorption of UV light. Dry blending pigment has a minimal effect as the dispersion and thus absorption characteristics are not sufficient to protect the base polymer.[112] It is important not to confuse UV performance with color-fading problems when dealing with pigments. Sometimes, a pigment may fade while the base polymer remains unaffected by true UV degradation. Thus, impact and tensile properties are unaffected while the appearance of the part changes.

Pigments should also be color stable when exposed to weathering. These pigments are generally referred to as UV grade pigments.[112]

Weathering Properties: UV Stabilizers For many years, polypropylene and polyethylene were stabilized against the detrimental effects of UV radiation using a low-molecular weight hindered amine light stabilizer (HALS) such as Tinuvin® 770. During the mid- to late-1980s, combinations of high-molecular weight HALSs with low-molecular weight HALSs provided a better balance of UV stability, thermal stability, and substrate compatibility. Some of the newest products for thicksection polyolefins include Tinuvin® 123 S, a solid, non-interacting, low-molecular weight NOR HALS; Chimassorb® 2020, a low volatility, oligomeric highperformance HALS; Tinuvin® 783, Tinuvin® 791, Chimassorb® 2030, and Chimassorb® 2040, new HALSs that exploit mixed HALS synergy; and Irgastab® FS 210, Irgastab® FS 410, Irgastab® FS 811, and Irgastab® FS 812, a family of phenol-free stabilizers that perform very well in color critical applications.[113]

37: Polyethylene: Overview

189

Weathering Properties by Material Supplier Trade Name Table 37-1. Service Life after Outdoor Weathering for Cyanox 2777, Cyasorb UV 531, and Cyasorb UV-3346 UV-Stabilized Polyethylene Greenhouse Film

190

The Effects of UV Light and Weather on Plastics and Elastomers

Table 37-2. Service Life after Outdoor Weathering for Cyasorb UV-3346 UV-Stabilized Polyethylene Greenhouse Film

Table 37-3. Mechanical Properties Retained after California and Pennsylvania Outdoor Exposure of Glass-Reinforced LNP Polyethylene

191

37: Polyethylene: Overview

Graph 37-1. Retention of Elongation after Atlas Weatherometer Exposure of High Density Polyethylene (HDPE) Plaques.[113]

Retention of Elongation (%)

80

60

40

20

0

Control

Tinuvin 622

Chimassorb 944

Tinuvin 783

Note: Sample: 3.125 mm (125 mil) HDPE plaques. Base stabilization: 0.06% Irganox B225. Exposure: 6000 hrs in a Atlas Weatherometer Ci65 @ 65◦ C, 0.35 W/m2 at 340 nm.

Graph 37-2. Impact Strength Retained after Atlas Weatherometer Exposure of Linear Low Density Polyethylene (LLDPE) Plaques.[113]

0.2% Tinuvin 783

0.2% Tinuvin 622

0.2% Chimassorb 944

0

20

40

60

80

100

Retained Impact Strength (%) 1000 hrs

6000 hrs

10000 hrs

Note: Sample: 3.125 mm (125 mil) butene-LLDPE plaques, rotomolded at 344◦ C (650◦ F). Base stabilization: 0.05% Irganox® 1010 + 0.02% DLTDP.

192

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 37-3. Kilolangleys of Exposure to Create 50% Tensile Strength Retained after Arizona Outdoor Exposure of HDPE-Pigmented Samples.[112]

0.25%

Failure Criteria: 50% retained tensile impact strength.

330

0.25%

Phthalocyanine Green

>700*

0.25%

Phthalocyanine Blue

230

0.25%

Azo-Red

250

Organic Yellow (tetrachloroisoindolinone) TiO2 (stabilized, coated Rutile)

570

0.5% 0.5%

210

0.5%

500

Ultramarine Blue

0.5%

460

Iron Oxide

0.5%

Cd-Red

230

Cd-Yellow

175 0

100

200

Unpigmented 300

400

500

600

700

800

Arizona (kLy) Note: Polymer: HDPE (Ziegler). Base stabilization: 0.03% Irganox 1076 + 0.05% calcium stearate. Light stabilization: 0.15% Tinuvin 770. Polyolefin thick sections, Arizona 45◦ south (start November). Source: Ciba: Stabilization of Polyolefins—Part 2. *No sample left.

Graph 37-4. Tensile Strength after Arizona Exposure of 0.96 Density Unstabilized Polyethylene with Various Pigments.[112] 5000 1% Carbon Black 1% Iron Oxide

Tensile Strength (psi)

4000

1% Phthalocyanine Green 1% Cadmium Red

3000

1% Cadmium Yellow

2000 1% Phthalocyanine Blue 1% TiO2 (Rutile)

Natural

1000

1% TiO2 (Anatase) 0 0

6

12

18

24

30

Months Exposed in Arizona

36

40

Chapter 38

Low Density Polyethylene Category: Polyolefin, thermoplastic. General Properties: Low density polyethylene that contains UV stabilizers demonstrates significantly

better UV performance than unstabilized polyethylene but shows reduced tensile strength and elongation at break.

Chapter 39

High Density Polyethylene Category: Polyolefin, thermoplastic.

Weathering Properties: Colored Material Carbon Black It has been found that even low levels of carbon black impart such a high level of protection to the polymer that no other light stabilizers or UV absorbers are required. Several theories have been advanced to explain this phenomenon. Schonhorn and Luongo stated that the photo-oxidative stabilization of high density polyethylene (HDPE) filled with carbon black is due not only to the light shielding capability of carbon black but also to its moderately low surface energy. Another possibility is that since the antioxidant properties of surface phenolic groups on carbon black have been well characterized, increased stability may be obtained by the interruption of chain propagation. Regardless, compounds containing 0.5% carbon black have been exposed for 10,000 hours in a weatherometer with no loss in tensile strength.[115]

White Pigments The weathering resistance of several types of white colorants—zinc oxide, exterior rutile TiO2 , and indoor rutile TiO2 as well as anatase TiO2 — was compared. In all instances, 2% pigment was used in combination with 0.5% of a UV absorber. Anatase TiO2 and indoor rutile TiO2 were totally ineffective in protecting HDPE and have poorer performance than the natural stabilized resin. However, with exterior grade TiO2 UV protection is somewhat improved.[115] Zinc oxide on the other hand, provides excellent UV protection to polyethylene. The tensile

strength of the zinc oxide formulation is significantly better than the one containing 2% TiO2 . For best weathering results, zinc oxide can be used provided its hiding power is sufficient for the intended application. For high opacity film and thinwalled containers, TiO2 is a better choice, because the tint strength of zinc oxide is too low to provide sufficient opacity. Weathering performance of an exterior grade TiO2 , without UV absorber, and at three different pigment concentrations shows that a formulation containing 2% TiO2 has only 50% of the weathering resistance of one containing 2% TiO2 with 0.5% hydroxybenzophenone.[115] Such systems can be improved through the use of nickel and hindered amine light stabilizers (HALSs). Systems with nickel complex light stabilizers and HALSs are not significantly affected after 2000 hours of weatherometer exposure, as compared to the formulation containing a hydroxybenzophenone absorber.[115] Yellow Pigments To study the effect of yellow pigments on HDPE weatherability, three pigments were selected and incorporated at a 1% concentration in an ethylenebutene copolymer containing 0.5% of a UV stabilizer. The pigments chosen were cadmium yellow, lithopone yellow, and coated molybdate.[115] After weatherometer exposure for 8000 hours, cadmium yellow had the best performance, followed by coated molybdate, and then lithopone yellow. Increasing the concentration of coated molybdate and lithopone yellow improved the weathering performance of the compound, but increasing the cadmium yellow concentration decreased its overall weathering effectiveness. Since this phenomenon has been demonstrated repeatedly, an assumption can be made that a reaction must occur between the pigment and the stabilizer at higher pigment concentrations. Apparently, this does not happen, or at

196

The Effects of UV Light and Weather on Plastics and Elastomers

least not as much, with coated molybdate or lithopone yellow pigment. The result of interaction of UV absorber and pigment, illustrated by the effect of UV stabilizer on 0.95 density polyethylene resin systems containing 1% and 2% cadmium yellow pigments, show that when no stabilizer is used the 2% system is somewhat better than the 1% cadmium yellow system. However, in formulations with stabilizer the opposite effect occurs.[115] To further study this interaction between stabilizers and cadmium yellow in a polyethylene system, samples were prepared containing two nickel complexes furnished by two suppliers. These nickel complexes are known to perform as light stabilizers, whereas hydroxybenzophenone was brittle at 10,000 hours of exposure. However, the 2% cadmium yellow system containing both nickel Complex A and B exhibited only a modest decrease in tensile strength after this same exposure period. The HALS would appear to be marginally better than the nickel complex but does not exhibit the green color inherent with nickel stabilizers. This further illustrates the complex interrelationships between stabilizers and pigments.[115] Both lithopone and cadmium yellow will fade during extended outdoor exposure. Although this is not a problem with single-pigment color formulations, the color change can be significant when cadmium yellow is combined with a more light stable pigment, such as ultramarine blue, to produce a green color.[115]

Red Pigments Of the three commonly used red pigments (quinacridone red, mercury-cadmium red, and lithopone red), the 1% quinacridone red formulation is found to be considerably better than either of the other two in 0.95 density stabilized polyethylene resins after 1000 hours of exposure in a weatherometer. There appears to be less difference between the lithopone red and the mercury-cadmium red pigments than between these pigments and the quinacridone red pigment.[115] The same relationship persists at a 2% pigment level. The 2% quinacridone red is still marginally better than the 2% mercury-cadmium red, and both are considerably better than 2% lithopone red after 10,000 hours of exposure. This indicates that as the

pigment concentration increases from 1% to 2%, mercury-cadmium red shows most improvement. Furthermore, the 1% quinacridone red pigment provides better stability than 2% lithopone red.[115] Previous studies have indicated that chemically pure (CP) cadmium red would offer virtually the same protection against UV degradation as mercurycadmium red. Although the quinacridone red and cadmium red pigments extend the outdoor weatherability of HDPE, they have limited use due to lack of color stability. The tint strength of both quinacridone and CP cadmium pigments will weaken when accelerated by a high humidity atmosphere. The most light stable red pigment is a combination of CP cadmium red and mercury-cadmium red pigments.[115] Earlier studies indicate that iron oxide is excellent for use in outdoor applications of HDPE. An unstabilized system of 0.5% iron oxide was virtually unchanged after 2000 hours in the weatherometer, while the tensile strength of 0.5% CP cadmium red started to decay considerably. Since both these formulations were unstabilized, this further demonstrates the significant screening effect of iron oxide in polyethylene. From past experience, iron oxide can be considered to be second only to carbon black in its ability to stabilize HDPE against UV degradation.[115]

Orange Pigments Four pigments at levels of 1% and 2% (coated molybdate, lithopone, CP cadmium, and mercurycadmium) in 0.95 density stabilized polyethylene were exposed for 10,000 hours in a weatherometer. At a concentration of 1%, CP cadmium orange appears to be 10–20% better than other pigments. Less difference can be seen among the pigments at the 2% level, although cadmium orange is still approximately 10% better than the others. It does appear that the coated molybdate pigment is somewhat better at 1% than at 2%, but this slight decrease falls within the experimental error range and can be considered negligible. The only pigment to show a significant difference between the two concentrations is lithopone orange. Since this pigment contains less cadmium than CP cadmium, the overall effect is quite the same as a reduced level of cadmium.[115] The effect of antioxidants on UV stabilization of 0.95 density stabilized polyethylene indicates that

197

39: High Density Polyethylene

the antioxidant system plays a major role in the outdoor performance of pigmented HDPE formulations. Two different types of antioxidants were compounded with a UV stabilizer and 1% and 2% cadmium orange. Antioxidant B imparted much more resistance to UV formulations with the proper antioxidants for outdoor applications.[115]

Blue and Green Pigments Phthalocyanine blue, cobalt blue, and ultramarine blue at a level of 1% were incorporated in an unstabilized polyethylene system and exposed for 2000 hours in a weatherometer. This test indicated that the phthalocyanine blue pigment provided two to three times as much UV protection as the ultramarine blue pigment. This level of protection in an unstabilized system is quite good. Cobalt blue, however, appears only moderately effective when compared to phthalocyanine blue.[115] It is also apparent that ultramarine blue imparts little or no protection to the polymer, since the performance of the compound containing ultramarine blue was a little better than natural HDPE. The same general trend is found in stabilized as well as unstabilized systems.[115] Many green formulations are prepared by combining ultramarine blue and cadmium yellow. Since the UV protection provided by ultramarine blue is poor, and only fair with cadmium yellow, it is not surprising that the combination is rather ineffective. Phthalocyanine green, however, imparts excellent UV resistance to polyethylene, as do some of the chrome greens. Compounds containing these pigments last longer than 6000 hours of weatherometer exposure with no loss of tensile strength.[115]

Pigment Dispersion Pigment dispersion is important in the compounding of any colored resin, since inadequate

dispersion can result in poor appearance, increased cost, and poor outdoor weatherability. To illustrate the effect of dispersion on weathering, three blends containing 0.5% CP cadmium red were prepared. Each of the blends was compared in order to achieve a good, fair, and poor pigment dispersion.[115] Tensile specimens from these compounds were aged in the weatherometer for 2000 hours. The tensile strength measured at 2 in./min (5 cm/min) showed very little difference between good/fair pigment dispersion. However, measurements at 20 in./min (50 cm/min) revealed that as pigment dispersion improved, there was a marked increase in tensile strength retention after UV exposure. As in the former case, the specimen with poor pigment dispersion was much less resistant to degradation than the good or even fair pigment system. These data clearly indicate that pigment dispersion is important to the UV resistance of a compound.[115] The degree of carbon black dispersion is also a determining factor in the effectiveness of a pigment for UV protection. Low levels of carbon black, properly dispersed, offer excellent UV protection. The usual condition is poor dispersion, normally compensated by using up to 2.5% black to give ultimate protection.[115]

Part Thickness The effect of part thickness plays a significant role in outdoor life. Since degradation of a part occurs from the exterior to the interior, the thicker the part, the greater the time required to penetrate to a depth that affects integrity. In one test, a 120 mil (3 mm) thick sample was found to have several times the life expectancy of a 30 mil (0.75 mm) sample of a yellow HDPE tested outdoors in Arizona.[115]

198

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 39-1. Tensile Strength after EMMA Accelerated Weathering of Chevron Phillips Marlex® HDPE with Channel Black and Furnace Black

39: High Density Polyethylene

199

Table 39-2. Tensile Strength after AcceleratedWeathering of Chevron Phillips Marlex® HDPE withVarious Degrees of Pigment Dispersion

200

The Effects of UV Light and Weather on Plastics and Elastomers

Table 39-3. Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with UV Absorber and Various Orange Pigment Systems

39: High Density Polyethylene

201

Table 39-4. Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with 2% Cadmium Yellow Pigment

202

The Effects of UV Light and Weather on Plastics and Elastomers

Table 39-5. Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with UV Absorber and Various Yellow Pigments

39: High Density Polyethylene

203

Table 39-6. Tensile Strength after Accelerated Weathering of Chevron Phillips Marlex® HDPE with 2% TiO2

204

The Effects of UV Light and Weather on Plastics and Elastomers

Table 39-7. Surface and Appearance after Accelerated Weathering of Chevron Phillips Marlex® HDPE with UV Absorber, Various Antioxidants and Green Pigment

39: High Density Polyethylene

205

Graph 39-1. Tensile Strength after Arizona Outdoor Weathering of Yellow Chevron Phillips Marlex® HDPE.

Graph 39-2. Tensile Strength after Weatherometer Exposure of Yellow Chevron Phillips Marlex® HDPE.

206

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 39-3. Tensile Strength after Weatherometer Exposure of Red Chevron Phillips Marlex® HDPE.

Graph 39-4. Tensile Strength after Weatherometer Exposure of Unstabilized Red Chevron Phillips Marlex® HDPE.

39: High Density Polyethylene

207

Graph 39-5. Tensile Strength after Weatherometer Exposure of Orange Chevron Phillips Marlex® HDPE.

Graph 39-6. Tensile Strength after Weatherometer Exposure of Blue Chevron Phillips Marlex® HDPE.

208

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 39-7. Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with 2% Zinc Oxide and 2% TiO2 .

Graph 39-8. Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with Varying Concentrations of TiO2 .

39: High Density Polyethylene

209

Graph 39-9. Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with 1% TiO2 and UV Stabilizers.

Graph 39-10. Tensile Strength after Weatherometer Exposure of Chevron Phillips Marlex® HDPE with Various Degrees of Pigment Dispersion.

Chapter 40

Ultrahigh Molecular Weight Polyethylene Category: Polyolefin, thermoplastic. General Properties: Molecular degradation may be prevented through the addition of suitable light stabilizers. The light-stabilized Ticona GUR® ultrahigh molecular weight polyethylene samples showed no degradation even after a four-week exposure period; in other words, their physical characteristics were preserved. The property values were determined for

test specimens 1.3-, 10-, and 20-mm thick after exposure to a xenon-lamp device.[117] The addition of light-absorbing substances provides UV light resistance (e.g., 2.5% carbon black being the most commonly used additive). When the finished product cannot be black, satisfactory UV resistance (a minimum of five years) can be obtained with 0.5 wt% stabilizer.[118]

Chapter 41

Polyethylene Copolymers General Properties: Polyethylene copolymers such as ethylene-vinyl acetate copolymer, polyethyleneacrylic acid copolymer, and polyethylene-ionomer copolymer are polyolefins that are comparable to elastomeric materials in softness and flexibility.[111]

Weathering Properties These materials are resistant to radiation in the visible spectrum. If polyethylene and its copolymers are exposed for long periods outdoors, they are degraded by radiation at the UV end of the solar spectrum and by atmospheric oxygen. They are also degraded by other light sources with a high proportion of UV radiation. The degradation mechanism of oxidation combines with high temperatures and leads to a deterioration in the mechanical properties and, ultimately, to the destruction of the material.[119]

If moldings are intended for outdoor use, they must be adequately protected from UV radiation. By far the best UV stability is achieved by adding special grades of carbon black. Proportions of 2–3% improve UV stability by a factor of ten to fifteen. White and chromatic pigments may also improve the UV stability of polyethylene but can also adversely affect it.[119] If moldings in the natural color or in other hues have to display excellent outdoor performance and fastness to light, the copolymers can be supplied on request with special light stabilizers. Good results are obtained with hindered amine light stabilizers, in some cases in combination with benzotriazole compounds. They can increase the resistance to weathering by a factor of about two to four, the extent depending upon the conditions.[119]

214

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 41-1. Elongation Retained after Xenon Arc Weatherometer Exposure of Ethylene-Vinyl Acetate Polyethylene Copolymer Greenhouse Film

Chapter 42

Polypropylene Category: Polyolefin, thermoplastic. General Properties: Without added UV stabilizers, polypropylene has poor UV resistance.

Weathering Properties: Stabilization Polypropylene homopolymers and copolymers for automotive applications have traditionally been stabilized with a combination of hindered phenolic/ hindered phosphite process stabilizers and hindered amine light stabilizers (HALSs). In organic pigmented applications, the addition of a benzotriazole UV absorber enhances light stability and helps prevent the pigment from fading.[121] Car manufacturers strive to produce automobiles that will look and perform well for ten years. For aesthetic and styling reasons, manufacturers often partially paint molded-in color polypropylene. Thus light stabilizers must provide long-term stability and must not interfere with the adhesion of coatings to the substrate. Noninteracting NOR HALSs help polypropylene producers achieve both

outstanding long-term light stability and good adhesion to thermoplastic polyolefin surfaces.[121] Polypropylene geomembrane systems used in exposed (i.e., nonburied) applications are susceptible to cracks and other UV-induced damage. Stevens Geomembranes/JPS Elastomerics has conducted extensive UV resistance testing on polypropylene geomembrane sheets. Xenon arc weatherometer (ASTM G-26) exposure of the sheets tested exceeded 10,000 hours at 80◦ C (176◦ F) with no indication of visual surface deterioration. The results from extensive outdoor exposure testing in Florida and Arizona using EMMAQUA accelerated aging techniques (ASTM G-90) showed that the polypropylene geomembranes tested passed the 4 million langley (167,360 MJ/m2 total radiation) mark with no evidence of visual surface deterioration.[122] Table 42-1 correlates langleys to years of outdoor performance. “A” is the average langleys received per day, based on a five-year average (1966–1970) of global solar radiation on the earth’s surface, as received on a horizontal surface; data obtained from measurements reported by the US Weather Bureau. “B” is the number of years required to obtain 4 million langleys at the location indicated.[122]

216

The Effects of UV Light and Weather on Plastics and Elastomers

Table 42-1. Conversions of EMMAQUA to Real-Time Performance by Geographic Location[122] Location

A

B

Albuquerque, NM

484

22

Argonne National Laboratory

327

34

Atlanta, GA

375

30

Cape Hatteras, NC

394

28

Fairbanks, AK

250

44

Grand Junction, CO

457

24

Los Angeles, CA

444

24

Miami, FL

451

24

New York, NY

323

34

Oak Ridge, TN

356

30

San Antonio, TX

411

26

Seattle/Tacoma, WA

307

36

42: Polypropylene

217

Weathering Properties by Material Supplier Trade Name Table 42-2. Tensile Strength after Florida and Puerto Rico Outdoor Weathering of Polypropylene Containing Various Antioxidant Stabilizers

218

The Effects of UV Light and Weather on Plastics and Elastomers

Table 42-3. Mechanical Properties Retained after California and Pennsylvania Outdoor Weathering of Glass-Reinforced Polypropylene

42: Polypropylene

219

Table 42-4. Tensile Strength Retained after Puerto Rico Outdoor Weathering for Polypropylene Containing Antioxidants and UV Stabilizers

220

The Effects of UV Light and Weather on Plastics and Elastomers

Table 42-5. Color and Gloss Changes after QUV Accelerated Weathering for Polypropylene Containing Microcal Calcium Carbonate and Pure Calcium Carbonate

Graph 42-1. Kilolangleys to 50% Retained Tensile Strength and Days to Embrittlement after 45◦ South Florida and Oven Aging at 120◦ C of UV-Stabilized Polypropylene Plaques.[121]

0.2% Tinuvin 770

0.2% Tinuvin 791

0.2% Chimassorb 944

600

400

200

kLys

0

200

400

600

Days

Note: Sample: 2 mm (80 mil) polypropylene plaques. Base stabilization: 0.15% Irganox B215 + 0.1% calcium stearate. Exposure: Florida 45◦ south and oven aging at 120◦ C. Test criteria: kilolangleys to 50% retained tensile strength + days to embrittlement.

221

42: Polypropylene

Graph 42-2. Surface Roughness after 45◦ South Florida Weathering Exposure of UV-Stabilized Polypropylene Plaques.[121] 1.2

Surface Roughness

1.0 0.4% Tinuvin 770 + 0.2% Tinuvin 328

0.8

0.6 Control 0.4 0.4% Tinuvin 791 + 0.2% Tinuvin 328

0.2

0

0

100

200

300

400

500

kLys Note: Sample: 2 mm (80 mil) polypropylene copolymer plaques. Base stabilization: 0.1% Irganox B225 + calcium stearate. Exposure: Florida 45◦ south. Test criterion: increase in kilolangleys to surface roughness.

Graph 42-3. Color Change, E, after Accelerated Weathering for UV-Stabilized Polypropylene Automotive Fibers.[124] 12 0.8% Chimassorb 944 10

0.8% Chimassorb 2020

∆E

8 6 4 2 0 0

113

301

602

902

1203

kJ Note: Samples contain 152/37 dtex, blue pigment. Base stabilization: Fiberstab® L112 + calcium stearate. Exposure: SAE J1885, WOM Ci65, 0.55 W/m2 at 340 nm, bpt 89◦ C.

Chapter 43

Polymethylpentene Weathering Properties

Category: Polyolefin, thermoplastic. ™

General Properties: Mitsui Chemicals TPX , a 4-methylpentene-1-based polyolefin, possesses many characteristics inherent in traditional polyolefins.

The weatherability of TPX™ is comparable with that of polypropylene.Although TPX™ is susceptible to UV deterioration, this can be virtually eliminated by adding UV stabilizers (MSW 303).[125]

Weathering Properties by Material Supplier Trade Name Graph 43-1. Izod Impact Strength Retained after Weatherometer Exposure for Mitsui TPX™ RT18 Polymethylpentene.

Chapter 44

Polyphenylene Sulfide Category: Thermoplastic. General Properties: Chevron Phillips Ryton® R-4-200NA is an advanced 40% fiberglass reinforced polyphenylene sulfide compound.

Weathering Properties by Material Supplier Trade Name Table 44-1. Material Properties Retained and Surface Erosion after Atlas Weatherometer Accelerated Weathering of Chevron Phillips Ryton® R4 Polyphenylene Sulfide

Chapter 45

General Purpose Polystyrene Category: Styrenic, thermoplastic. General Properties: General purpose polystyrene is available in various grades such as easy flow, intermediate flow, and high heat resins.

Weathering Properties Polystyrene undergoes light-induced yellowing upon exposure to UV light. Although the origin of the yellowing is not clear, the presence of air slows down the yellowing process. Yellowing is attributed to conjugated polyenes, various oxygenated species, or products of ring-opening reactions.[5] BASF Polystyrol® is stabilized against aging caused by exposure to atmospheric oxygen at elevated temperatures. Under normal light and temperature conditions indoors, parts made of Polystyrol® retain their appearance and functionality for years. The UV rays in direct sunlight are primarily responsible for damage outdoors. This aging shows up both as a gradual change in appearance (i.e., yellowing and loss of surface gloss) and as a decrease in the mechanical strength. Dark-colored products have better resistance than pale or transparent products.

For the above reasons, polystyrene is not recommended for articles that are used outdoors for a prolonged period. The yellowing resistance of polystyrene can be significantly improved by the addition of UV stabilizers.[128] Under the normal conditions of light and temperature encountered indoors, Polystyrol® moldings retain their appearance and perform their functions efficiently for many years.[129] Polystyrene foams generally have poor outdoor weathering resistance and are not recommended for long-term outdoor use. The plastic matrix deteriorates when exposed to direct sunlight for extended periods, as evidenced by a characteristic yellowing, loss of surface gloss, and by a decrease in mechanical strength. Darker formulations perform better than pale or transparent types.[130] To protect polystyrene foam against the effect of outdoor weathering and physical damage, an adequate coating should be applied on the surface.[130] Materials subjected to oxygen are degraded much faster in the presence of radiation than in its absence and vice versa. The discoloration of polystyrene occurs more rapidly when irradiation takes place in air or oxygen.[3]

Weathering Properties by Material Supplier Trade Name Table 45-1. Photo-Oxidation of Polystyrene[3] Oxygen Pressure (mm)

UV Radiation Time (hrs)

Oxygen in Product (%)

0

0

0.11

Nearly colorless

0

250

0.13

Light yellow

20

0

0.10

Nearly colorless

20

250

0.14

Yellow–orange

Note: The total exposure time is 250 hrs at 115–120◦ C in all cases.

Color

228

The Effects of UV Light and Weather on Plastics and Elastomers

Table 45-2. Mechanical Properties Retained after California and Pennsylvania Outdoor Weathering of Glass-Reinforced General Purpose Polystyrene

45: General Purpose Polystyrene

229

Graph 45-1. Yellowness Index after Atlas Fadeometer Exposure of General Purpose Polystyrene.

Graph 45-2. Yellowness Index after Fluorescent Lamp Exposure of BASF Polystyrol® General Purpose Polystyrene.

Chapter 46

High Impact Polystyrene Category: Styrenic, thermoplastic. General Properties: High impact polystyrene (HIPS) is modified with polybutadiene elastomers. The high impact grades contain 6–12% of the elastomer. The elastomers are introduced into the base polymer to improve the impact resistance and deformation before fracture. Through the incorporation of different elastomers into the chain, products with a wide range of properties can be produced. NOVA Chemicals Styrosun® resins are weatherable HIPS specifically designed for use in outdoor applications. Styrosun® contains an inherently weather resistant rubber that is cross-linked and grafted into the polymer matrix. This unique polymer structure provides long-term color stability and physical property retention.[132]

Weathering Properties Unmodified HIPS resins usually experience greater change from outdoor exposure than general purpose polystyrene formulations. HIPS resins usually show less change than resins modified with ignition-resistant chemical additives.[133] Solar radiation, particularly at the UV end of the spectrum, acts together with atmospheric oxygen to cause embrittlement and yellowing. These changes occur mainly in the butadiene elastomer.[13] Styrosun® resins are resistant to sunlight and maintain significant physical properties after weathering. The weather resistant properties of Styrosun® resins are achieved by combining proprietary UV stabilization technology with an inherently UVstable impact modifier.[134] The key advantage of Styrosun® resin is the retention of physical properties after outdoor weathering. Applications using Styrosun® resins maintain functional product life and toughness after UV exposure.[134]

Molded plaques of Styrosun® and typical competitive outdoor polymers were exposed at four different locations in the United States and color retention (as E) was monitored over time. The color retention performance of Styrosun® HIPS, acrylonitrile-styrene-acrylate (ASA), UV-stabilized acrylonitrile-butadiene-styrene (UV-ABS), UVstabilized high impact polystyrene (UV-HIPS), and filled polypropylene (PP) was compared after 18 months at four different exposure sites in the United States. The results demonstrated that Styrosun® and ASA had equivalent performance (E range 4.9– 6.5). UV-ABS and UV-HIPS were also equivalent in performance (E range 18.5–26.1). Filled PP exhibited the smallest change in color over this exposure period (E range 1.6–2.2). A E value of 5 or less is generally considered to be negligible unless directly compared to an unexposed control.[132] Molded plaques of Styrosun® and various other materials were exposed in Xenon Arc WeatherOmeters® (ATLAS Material Testing Technology LLC) as per ASTM protocol G155 Cycle 2. By calculation, 3000 hours of accelerated weathering by this protocol is theoretically equivalent to one year of exposure in Florida or 0.8 years in Arizona. The color retention of white Styrosun® after 3000 hours of accelerated weathering was identical to its color retention after 18 months of Florida outdoor weathering. In this accelerated exposure test, neitherASAnor UV-ABS exhibited the same degree of color change seen after Florida exposure. However UV-ABS was again less resistant to color change than Styrosun® . Filled PP exhibited the smallest change in color over this exposure period. Examination of the accelerated weathering E graph also illustrates the significant amount of scatter in the data.[132] The samples were also tested for retained impact strengths. There are three impact results reported by a Dynatup® (Instron Corporation) impact test instrument. The “energy at maximum load” is the energy at the moment of impact, the “total energy”

232

The Effects of UV Light and Weather on Plastics and Elastomers

is the energy required to break the test plaque, and the “maximum load” is the weight required to break the test plaque. When these absolute numbers were compared, in all cases Styrosun® was stronger and tougher than filled PP, but not as strong as UV-ABS. When the percentage retention values were compared, Styrosun® was found to retain its properties significantly better than UV-ABS and similar to filled PP.[132]

Addition of UV stabilizers overcomes the yellowing and brittleness associated with prolonged exposure of unmodified HIPS to sunlight.[132] Combinations of UV absorbors (UVAs) and hindered amine light stabilizers (HALSs) can provide improved performance.[135]

Weathering Properties by Material Supplier Trade Name Table 46-1. Color Change, E, after 18 Months of Florida Outdoor Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials Material Family

High Impact Polystyrene

Material Grade

NOVA Chemicals Styrosun® HIPS and Other Materials

Reference Number

132

Exposure Conditions

Florida, Arizona, Kentucky, Illinois

Exposure Time

18 months Styrosun®

Materials

3600

ASA

UV-ABS

UV-HIPS

Filled PP

SURFACE AND APPEARANCE E Florida

5.2

5.4

18.5

19.4

2.2

E Arizona

6.5

6.5

25.3

23.7

1.8

E Kentucky

5.0

4.9

24.2

22.0

1.6

E Illinois

5.8

4.8

26.1

23.1

1.6

Table 46-2. Color Change, E, after 18 Months of Florida Outdoor Exposure and 3000 hours of Accelerated Weathering for NOVA Chemicals Styrosun® HIPS and Other Materials Material Family

High Impact Polystyrene

Material Grade

NOVA Chemicals Styrosun® HIPS and Other Materials

Reference Number

132

Exposure Conditions

Florida Outdoor Exposure

Exposure Time Materials

Accelerated Exposure

18 months Styrosun®

3600

3000 hrs

ASA

UV-ABS

Filled PP

5.4

18.5

2.2

Styrosun®

3600

ASA

UV-ABS

Filled PP

1.3

7.5

2.1

SURFACE AND APPEARANCE E

5.2

5.2

233

46: High Impact Polystyrene

Table 46-3. Impact Retention after 3000 hours of Accelerated Weathering for NOVA Chemicals Styrosun® HIPS and Other Materials Material Family

High Impact Polystyrene

Material Grade

NOVA Chemicals Styrosun® HIPS and Other Materials

Reference Number

132

Exposure Conditions

Accelerated Exposure

Exposure Time Materials

3000 hrs Styrosun®

3600

Styrosun®

3600

UV-ABS

Filled PP

RETENTION OF ENERGY AT MAXIMUM LOAD Impact Retention (%)

80.7

102.7

39.1

107.2

88.3

76.9

42.9

135.1

88.4

82.6

28.2

98.1

RETENTION OF TOTAL ENERGY Impact Retention (%) RETENTION OF MAXIMUM LOAD Impact Retention (%)

Graph 46-1. Yellowness Index after Fadeometer Exposure of Dow Styron® Impact and Flame-Retardant Polystyrene and Dow Styron® Unmodified Polystyrene.

234

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 46-2. Color Change, E, after Florida Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials.[132] 25

FLORIDA 20

∆E

15

10

5

0 White Styrosun 3600 3 months

White ASA 6 months

White UV ABS 9 months

White UV HIPS

12 months

15 months

White filled PP 18 months

Graph 46-3. Color Change, E, after Arizona Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials.[132] 30

ARIZONA 25

∆E

20 15 10 5 0 White Styrosun 3600 3 months

White ASA 6 months

White UV ABS 9 months

White UV HIPS

12 months

15 months

White filled PP 18 months

235

46: High Impact Polystyrene

Graph 46-4. Color Change, E, after Kentucky Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials.[132] 30

KENTUCKY 25

∆E

20 15 10 5 0 White Styrosun 3600 3 months

White ASA 6 months

White UV ABS 9 months

White UV HIPS

12 months

15 months

White filled PP 18 months

Graph 46-5. Color Change, E, after Illinois Outdoor Exposure of NOVA Chemicals Styrosun® HIPS and Other Materials.[132] 30

ILLINOIS 25

∆E

20

15

10

5

0 White Styrosun 3600 3 months

White ASA 6 months

White UV ABS 9 months

White UV HIPS

12 months

15 months

White filled PP 18 months

236

The Effects of UV Light and Weather on Plastics and Elastomers

Energy at Maximum Load (% Retention)

Graph 46-6. Impact Property Retention, Energy at Maximum Load, after 3000 hours of Atlas WeatherOmeters® Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials.[132] 140.0 120.0 100.0 80.0 60.0 40.0 20.0 0.0 0

500

1000

1500

2000

2500

3000

Exposure Time (hrs) UV ABS-BLACK

SSUN 3600 BLACK

SSUN 6600 BLACK

FILLED PP-WHITE

Graph 46-7. Impact Property Retention, Total Energy, after 3000 hours of Atlas Weather-Ometers® Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials.[132] 200.0

Total Energy (% Retention)

180.0 160.0 140.0 120.0 100.0 80.0 60.0 40.0 20.0 0.0 0

500

1000

1500

2000

2500

3000

Exposure Time (hrs) UV ABS-BLACK

SSUN 3600 BLACK

SSUN 6600 BLACK

FILLED PP-WHITE

237

46: High Impact Polystyrene

Graph 46-8. Impact Property Retention, Maximum Load, after 3000 hours of Atlas Weather-Ometers® Exposure for NOVA Chemicals Styrosun® HIPS and Other Materials.[132]

Maximum Load (% Retention)

120.0 100.0 80.0 60.0 40.0 20.0 0.0 0

500

1000

1500

2000

2500

3000

Exposure Time (hrs) UV ABS-BLACK

SSUN 3600 BLACK

SSUN 6600 BLACK

FILLED PP-WHITE

Graph 46-9. Impact Strength after Xenon Arc Weathering of HIPS as per ISO 4692-2.[135] 80

Impact Strength (kJ/m2)

60 0.25% UVA 0.25% HALS 40

20

Control

0 0

250

500

750

1000

Exposure Time (hrs) Note: 2 mm plaques; base stabilization: 0.05% Irganox® 245; UVA:Tinuvin® P, Tinuvin® 327, or Tinuvin® 328; HALS:Tinuvin® 770, Tinuvin® 765, or Chimassorb® 119.

238

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 46-10. Yellowness Index after Xenon Arc Weathering of HIPS as per ISO 4892-2.[136] 20

Control

Yellowness Index

15

10

5

0

0.1% Tinuvin P 0.1% Tinuvin 770

0

1000

2000

3000

Exposure Time (hrs)

4000

5000

Chapter 47

Polysulfone Category: Thermoplastic. General Properties: Solvay Plastics Udel® polysulfone is an amorphous high performance polymer.

upon outdoor exposure. Weather resistance can be improved by the addition of carbon black. Protective paints or coatings can be used to preserve the properties of polysulfone articles exposed to direct sunlight.[137]

Weathering Properties Because of the aromatic ether backbone, polysulfone is susceptible to chemical degradation

Weathering Properties by Material Supplier Trade Name Table 47-1. Mechanical Properties Retained after Outdoor Weathering of Glass-Reinforced Polysulfone in California and Pennsylvania

240

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 47-1. Tensile Strength after Xenon Arc Weatherometer Exposure of Polysulfone.

Chapter 48

Polyethersulfone Category: Engineering thermoplastic. General Properties: Polyethersulfone (PES) is a heat-resistant, transparent, amber, noncrystalline engineering plastic.[138]

BASF Ultrason® moldings yellow and embrittle quickly when exposed outdoors. The moldings can be protected from degradation by the incorporation of carbon black, surface coating, or metallizing.[45]

Weathering Properties The weathering resistance of natural PES resin is not very good and therefore it is not suitable for outdoor use.[138]

Weathering Properties by Material Supplier Trade Name Graph 48-1. Tensile Strength after Xenon Arc Weatherometer Exposure of PES.

Chapter 49

Styrene-Acrylonitrile Copolymer Category: Thermoplastic. General Properties: The properties of BASF Luran® styrene-acrylonitrile (SAN) copolymer are primarily determined by the acrylonitrile content and the molecular weight or molecular weight distribution.

Weathering Properties The mechanical properties of Luran® specimens deteriorate after one or two years of outdoor exposure

(at an angle of 45◦ facing south in Ludwigshafen, Germany). The extent to which the mechanical properties are impaired depends on the nature of the specimen and the test procedure. Other consequences of outdoor exposure are yellowing and a rough surface. Luran® resins are also available in a UV-stabilized form. It can be seen that the rate of decrease in flexural strength is much less for Luran® resins containing UV stabilizers. Another advantage of UV stabilization is that the color retention is considerably improved.[139]

244

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 49-1. Surface and Appearance Properties after Arizona Outdoor Weathering of Dow Tyril® SAN Copolymer

Graph 49-1. Yellowness Index after Arizona Outdoor Weathering of Dow Tyril® SAN Copolymer.

49: Styrene-Acrylonitrile Copolymer

Graph 49-2. Yellowness Index after UV-CON Accelerated Weathering Exposure of SAN Copolymer.

245

Chapter 50

Styrene-Butadiene Copolymer Category: Styrene-butadiene, thermoplastic. General Properties: Chevron Phillips K-Resin® is a transparent styrene-butadiene copolymer that can be impact modified as well as UV stabilized.

Weathering Properties K-Resin® copolymers are styrenic copolymers that will yellow and ultimately craze and embrittle with long-term exposure to direct sunlight. Previous weatherometer testing shows that K-Resin® is susceptible to yellowing and physical property deterioration induced by UV light. With the addition of appropriate UV stabilizers, the estimated life of a K-Resin® part may be extended. In general, K-Resin® will withstand UV exposure for approximately three months before excessive brittleness and yellowing are evident. Modifying K-Resin® with commercially available UV stabilizers will extend the outdoor life of the material for up to eighteen months depending on the stabilizer package used.[142]

Indoor UV Light Resistance and Indirect Sunlight[142] K-Resin® polymers are used in many display applications that are often subjected to reduced levels of UV light, by indirect sunlight or fluorescent lighting. A study was conducted to determine the extent of K-Resin® yellowing under these conditions. Four samples evaluated in the test included KR01, KR03, and KR03 with two different UV stabilizers (Ciba Specialty Chemicals Tinuvin® P and Tinuvin® 770). Samples were prepared by adding 0.5% of each UV stabilizer to a K-Resin® sample by dryblending the sample prior to extrusion and palletizing. Tinuvin® P is a UV absorber and Tinuvin® 770 is a hindered amine light stabilizer. The clarity of these blends was

very good, but some slight yellow color developed when the UV stabilizers were initially added. The samples were compression molded into 15.24 mm plaques. One set was placed in a UVCON® tester, approximately 4 (10 cm) from a bank of four fluorescent lights. Another set was placed on a window ledge exposed to indirect sunlight. A third set was placed in a dark container so that the specimens were not exposed to any light source. Hunter “b” color was measured initially and at intervals of 3, 6, 12, 18, and 24 months. As expected, the non-UV stabilized KR01 and KR03 responded similarly in all circumstances. The UV-stabilized polymers demonstrated improved resistance to yellowing when exposed to UV light sources. When no light source was present, none of the K-Resin® samples yellowed appreciably over the two-year period. In the UV-CON® test, the most severe test, the addition of a UV additive improved the performance substantially. KR01 and KR03 unmodified samples discolored significantly between six and twelve months, and continued to further discolor with extended exposure. Tinuvin® P modified KR03 outperformed Tinuvin® 770 modified KR03, after two years, having about half as much yellow color development. In indirect sunlight, the modified KR01 and KR03 samples discolored most significantly after twelve months. The KR03 sample containing 0.5% Tinuvin® P performed better, with only minimal yellowing over the two-year test period. Tinuvin® 770 modified KR03 did not perform as well as Tinuvin® P modified KR03, discoloring significantly after twelve months. K-Resin® polymers, which will yellow when subjected to long-term exposure to direct sunlight, can also yellow with less severe UV exposure. Yellowing can be significantly reduced by the addition of UV stabilizers. Tinuvin® P is more effective than Tinuvin® 770 for fluorescent and indirect light exposure. K-Resin® parts stored in the dark showed no significant yellowing over at least a two-year period.

Chapter 51

Polyvinyl Chloride Category: Vinyl, thermoplastic.

Thickness

General Properties: PolyOne Geon® exterior compounds are UV stable and can withstand extreme weather conditions with good color and impact retention over time.

Degradation as a result of environmental exposure begins on the surface where radiation intensity is the greatest. The thicker sections provide a larger reservoir of stabilizers. The stabilizer readily, and constantly, migrates from the bulk to the film’s surface. Thus thicker films and sheets contain more of the preventative stabilizer, resulting in longer life.

Weathering Properties Of the synthetic polymers, polyvinyl chloride (PVC) is best known for its tendency to undergo photoyellowing. Yellowing is often the result of photothermal mechanisms that lead to the formation of conjugated polyenes. The rate of yellowing in the white profiles widely used in siding, window frames, and pipes can be slowed through the use of an opacifier, generally rutile titania. The reaction is localized in the surface layers of the polymer especially in opaque formulations used in building applications. The wavelengths that cause yellowing of PVC (the visible radiation >400 nm) also tend to cause photobleaching. Several possible photobleaching mechanisms are reported in the literature but the process is little understood.[11] The ability of plasticized PVC to withstand outdoor exposure is influenced by many factors. These include the flexibility and the thickness of the fabricated product as well as the additives that are incorporated into the formulation.[11] Testing has yielded the following recommendations: plasticizer concentration in the range of 35 parts per hundred parts of PVC, use of a good phosphate ester as 10% of the plasticizer system, use of some pigmentation, and incorporation of treated rutile titanium dioxide. UV light absorbers must be included in clear films. In addition to the epoxy and barium-cadmium-containing stabilizers, include a phosphate ester in the stabilizer system. The thicker the film, the longer will be its expected outdoor life.[11]

Plasticizers[11] All plasticizers, and all plasticizer concentrations, do not perform in the same manner. Generally, more volatile plasticizers will yield films with a shorter outdoor life expectancy. Clear films, including a UV absorber (UVA), plasticized at 50 phr (parts per hundred resin) were exposed in 4 mil (100 µm), 10 mil (250 µm), and 20 mil (500 µm) thicknesses in Florida. In this evaluation, four general-purpose plasticizers were studied: two were highly branched— diisodecyl phthalate (DIDP) and diisononyl phthalate (DINP), one was singly branched—dioctyl phthalate (DOP), and the fourth plasticizer—heptylnonyl-undecyl phthalate—was essentially linear. This study revealed the benefit of using the lessbranched phthalate plasticizers for products to be used outdoors. A prior, limited, outdoor weathering study in Florida showed 35 phr plasticizer to be the most beneficial for long-term durability. This was based on work using two plasticizer systems without UVA. One was DOP and the other plasticizer system was 90% DOP and 10% 2-ethylhexyl diphenyl phosphate. Also seen in this study was the synergistic influence of the phosphate plasticizer in thin films of 4 mil (100 µm) thickness. At the lower two concentrations, where films are relatively stiff, the increase in service life due to the addition of a phosphate plasticizer is 9–15%. Soft and flexible films, those with 50 and

250

The Effects of UV Light and Weather on Plastics and Elastomers

Table 51-1. Exposure Results of Various Plasticized Films with Varying Thicknesses Plasticizer

Film Thickness

Exposure Time

Result

DIDP

4 mil (100 µm)

24 months

Entirely brown

DIDP

10 mil (250 µm)

30 months

Entirely brown

DIDP

20 mil (500 µm)

30 months

Entirely brown

DINP

4 mil (100 µm)

24 months

Entirely brown

DOP

4 mil (100 µm)

36 months

No browning

DOP

10 mil (250 µm)

36 months

No browning

DOP

20 mil (500 µm)

36 months

No browning

4 mil (100 µm)

36 months

No browning

10 mil (250 µm)

36 months

No browning

20 mil (500 µm)

36 months

No browning

Heptyl-nonyl-undecyl phthalate Heptyl-nonyl-undecyl phthalate Heptyl-nonyl-undecyl phthalate

Table 51-2. Outdoor Life of DOP-Plasticized 4 mil (100 µm) Thick Films with Varied Plasticizer Levels Plasticizer Level

Outdoor Life*

20 phr

13 months

35 phr

23 months

50 phr

15 months

70 phr

11 months

∗ Elongation

was the measure for outdoor life.

70 phr of plasticizer, have a dramatic increase in life expectancy. The addition of a small amount of phosphate plasticizer yields a 50% increase in outdoor serviceability. Later work from the same laboratory showed the response of films containing UVAs and plasticized at 50 phr to outdoor aging when the plasticizer system is varied from all DOP to all 2-ethylhexyl diphenyl phosphate. The optimum level of phosphate plasticizer was determined to be 10–15% of the total plasticizer system. The benefit of the phosphate synergism is seen in 20 mil (50 µm) thick films as well as in the thin 4 mil (100 µm) films.

Additional Plasticizers General performance monomerics diisodecyl glutarate (DIDG) and DOP were tested with polymerics G-4,000 (glutarate—viscosity, cps) and G-12,000 for yellowness index change after two, four, and six months of direct aging. Both monomerics show relatively high initial and longer-term tendencies to yellow. G-4,000 and G-12,000 provide excellent short-term and longer-term resistance to discoloration by yellowing. Glutarate polymerics in general have a proven history of providing good resistance to weathering for PVC compounds.[143]

251

51: Polyvinyl Chloride Table 51-3. Direct Weathering of Select Plasticizers in PVC[143] Yellowness Index Change Exposure Time

DIDG

DOP

G-4,000

G-12,000

2 months

8.25

4.93

0.17

0.5

4 months

9.25

8.93

3.17

1.5

6 months

14.9

9.85

4.55

5.35

Note: 45◦ south, with backing, South Miami. Recipe: PVC—100, BaCd—1, UV stabilizer—0.5, Plasticizer—67, ESO—3.

Table 51-4. Underglass Weathering of Select Plasticizers in PVC[11] Yellowness Index Change Exposure Time

DIDG

DOP

A-20,000

G-12,000

2 months

−1.9

2.36

−1.08

−2.83

4 months

2.94

6.05

0.57

−0.28

6 months

8.38

6.05

2.72

0.34

Note: 45◦ south, with backing, South Miami. Recipe: PVC—100, BaCd—1, UV Stabilizer—0.5, Plasticizer—67,ESO—3.

Underglass weathering net changes from initial yellowness values for monomerics DOP and DIDG and polymerics A-20,000 (adipate—viscosity) and G-12,000 were tested. The magnitude of short-term and longer-term yellowness index change values is lesser overall for the underglass-weathered compounds compared with those which were directly aged. Polymeric polyesters A-20,000 and G-12,000 provide about a threefold reduction in yellowness index change compared with the general performance monomerics.[11]

Stabilizers [11] When formulating flexible PVC films and sheets for outdoor use, the influence of the complete stabilizer system including epoxidized soybean oil, several metal salts of organic acids, a phosphate ester, and a UVA (2-hydroxy-4-methoxy benzophenone) must be considered. The influence of stabilizers on the outdoor durability of flexible PVC was measured using epoxycadmium stabilizers individually and in synergistic mixtures with 2-hydroxy-4-methoxy benzophenone.

“Epoxy-cadmium” is a synergistic mixture of an epoxy compound, a barium-cadmium salt of an organic acid, and a phosphate ester. When only the epoxy compound and barium-cadmium salt were used, decomposition occurred quite early, through discoloration, serious tack formation, and the loss of elongation. The addition of a UV light stabilizer, such as 2-hydroxy-4-methoxy benzophenone, had essentially no benefit. However, triphenyl phosphate by itself yielded a longer life than either of the above stabilizers. When 2-hydroxy-4-methoxy benzophenone was added to triphenyl phosphate, there was a large improvement in the weathering life of the film. Although the epoxy and barium-cadmium constituents were not necessarily needed to achieve good outdoor durability, they are definitely required to ensure adequate heat stability during the processing of flexible PVC.

Pigments and Colorants The outdoor life expectancy of flexible PVC may be improved through pigmentation.

252

The Effects of UV Light and Weather on Plastics and Elastomers

Table 51-5. Titanium Dioxide in Films of Three Thicknesses Exposed in Florida[11] Thicknesses

TiO2

UVA

Time to Failure

4 mil (100 µm)

No

No

22 months

10 mil (250 µm)

No

No

22 months

20 mil (500 µm)

No

No

22 months

4 mil (100 µm)

Yes

No

32 months

10 mil (250 µm)

Yes

No

47 months

20 mil (500 µm)

Yes

No

76 months

Increasing quantities of anatase and rutile titanium dioxide improved the reflectance characteristics of plasticized PVC. Accelerated weathering studies revealed rutile titanium dioxide to be decidedly superior to anatase as a light-stabilizing agent.[11] It was found that “When an untreated rutile absorbs UV light, the absorbed energy goes into a photochemical reaction that liberates active oxygen.” For this reason, rutile that is used in plastics is given a surface treatment which inhibits this photochemical reaction and causes the absorbed UV energy to be dissipated as heat.[11] Colored pigments strongly assist in the maintenance of mechanical properties by protecting the plasticized PVC compositions from degradation. Combinations of pigments are beneficial for longterm outdoor aging because they can shield the visible and the UV range—thus the use of rutile titanium dioxide in combination with a selected colored pigment was found to provide quite good weathering resistance.[11] Similar outdoor studies were carried out with blue and black films. Both colorants, phthalocyanine blue at 0.9 phr and channel black at 1 phr, definitely extend the weathering life of flexible PVC films and sheets. The 20 mil (500 µm) blue film survived 80 months, over six and a half years, before failing the room temperature brittleness test.[11] The use of black pigments is encouraged to achieve the maximum outdoor life for flexible PVC products. The 20 mil (500 µm, 0.5 mm) sheets withstood five years of Florida exposure before reaching the 0◦ C brittleness temperature. Extrapolating this, a 60 mil (1.5 mm), black pigmented, flexible PVC sheet can withstand more than ten years of outdoor exposure in most environments.[11]

Yellowing PVC is susceptible to photoyellowing. “The photothermal mechanisms leading to the formation of conjugated polyenes that cause yellowing is well understood and documented in the literature. An opacifier (generally rutile titania) is used to slow down the rate of yellowing in white profiles widely used in siding, window frames, and pipes. The reaction is localized in the surface layers of the polymer especially in opaque formulations used in building applications. The activation energy for dehydrochlorination is reported to have a temperature coefficient of 8–18 kJ/mol, suggesting this process is readily enhanced at high temperatures. As with wool and paper, while the UV wavelengths cause yellowing of PVC, the visible radiation >400 nm tends to cause photobleaching. Several possible photobleaching mechanisms are reported in the literature but the process is little understood.”[5]

Weathering Properties: Stabilization Ciba® Tinuvin® XT 833 protects PVC from the harmful effects of light exposure and helps it maintain its initial appearance, initial tensile and elongation properties, and physical integrity during long-term weathering. In PVC roofing membranes, for example, it minimizes discoloration and embrittlement and enables the membranes to retain their moisture barrier properties and reflectivity. In some cases, studies show that even in an acidic environment Tinuvin® XT 833 can double the expected

253

51: Polyvinyl Chloride

lifetime of flexible PVC compared to UVAs. As PVC degrades, it releases hydrochloric acid which terminates the effectiveness of hindered amine light stabilizers (HALSs) as a light stabilizer or at leastseverely reduces HALS activity. Thus a unique class

of light stabilizers known as NOR HALSs (nonbasic HALSs) was developed. This completely new molecule is synthesized to function well in an acidic environment.[144]

Graph 51-1. Elongation after Xenon Exposure of Various UV Stabilized PVC Formulations.[144]

Elongation (%)

900 800

Tinuvin XT 833

700

Commercial PVC A

600

Commercial PVC B

500 400 300 200 100 0

0

6000

8000

Xenon Exposure (hrs)

Graph 51-2. Elongation Retention after Xenon Exposure of Various UV-Stabilized PVC Formulations.[144]

Elongation Retention (%)

80 70 60 50 40 30 20 10 0

2.0% UVA #1

2.0% UVA #2

Xenon Exposure (6000 hrs)

1.0% Tinuvin XT 833

254

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 51-3. Yellowness Index after Xenon Exposure of Various UV-Stabilized PVC Formulations.[144]

Yellowness Index

10 8 6

4

2 0

1.0% UVA #1

2.0% UVA #2

Xenon Exposure (8000 hrs)

1.0% Tinuvin XT 833

Chapter 52

Chlorinated Polyvinyl Chloride Category: Vinyl, thermoplastic. General Properties: Chlorinated polyvinyl chloride (CPVC) has physical properties similar to PVC, but offers higher heat deflection properties for extended temperature range uses.

Weathering Properties CPVC has reasonable weathering properties.[145]

Graph 52-1. Drop Weight Impact Strength Retained after Florida Outdoor Weathering Exposure of CPVC.

Chapter 53

ABS Polyvinyl Chloride Alloy Category: Acrylonitrile-butadiene-styrene (ABS) polymer, polyvinyl chloride (PVC) compounds, thermoplastic, vinyl. General Properties: Novatec Novaloy® 9000 is a specialty engineering alloy of ABS/PVC and has been formulated to provide excellent retention of physical properties upon aging.[147]

Weathering Properties Halogen-containing polymers (e.g., PVC) are relatively cheap and readily available materials. However, the weatherability (e.g., the light stability of halogen-containing polymers) is poor, leading to relatively short lifetimes, particularly in pigmented formulations.[148] The retention of mechanical and surface and appearance properties following exposure to an outdoor environment is important. Acrylic materials

generally have exceptional weathering performance. Blends of PVC and acrylic materials may be attractive in some situations.[148] For example, compared to unmodified acrylics, acrylics modified by the addition of PVC may be cheaper, have increased toughness, exhibit reduced flammability, and have desirable melt-flow properties. However, while the weathering performance of an acrylic/PVC blend is generally improved compared to PVC alone, the addition of PVC to acrylics reduces the weathering performance compared to unmodified acrylics. Thus, an acrylic/PVC blend may exhibit unacceptable color stability and degradation in appearance and mechanical properties following exposure to sunlight or in weathering tests. For unmodified pigmented acrylic/PVC blends the extent to which this “chalking” occurs is dependent upon the amount of PVC present in the blend, but even at concentrations of <20% wt/wt PVC a noticeable color shift, E, occurs after 6000 hours of exposure.[148]

258

The Effects of UV Light and Weather on Plastics and Elastomers

Table 53-1. Color Change after Accelerated QUV Weathering of Novatec Novaloy® 9000 ABS/PVC Alloy

Chapter 54

Acrylic (PMMA) Polyvinyl Alloy Category: Acrylic, thermoplastic, vinyl, polymethylmethacrylate (PMMA). ®

General Properties: Novatec Kydex 550 and Kydex® 510 are weatherable acrylic/PVC sheets.

Weathering Properties Kydex® 550 and Kydex® 510 offer superior resistance to UV rays and will show no significant color degradation when exposed to UV rays.[150]

Chapter 55

Polycarbonate ABS Alloy Category: ABS polymer, polycarbonate, thermoplastic. General Properties: Bayer Bayblend® PC/ABS is Bayer’s trade name for a family of amorphous, thermoplastic polymer blends based on polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS). Dow Automotive Pulse® engineering resins are PC/ABS alloys.

Weathering Properties Due to the UV resistance of Bayblend resins, molded parts will retain good mechanical and color hold properties without light-protective coatings.[151]

Table 55-1. Color Change, E, after HPUV and Xenon Arc Accelerated Indoor Exposure of Dow Chemical Pulse 1745

Chapter 56

Biodegradable Polyethylene Films Category: Polyethylene (PE), starch. General Properties: PE agricultural films can be starch modified for biodegradability. Studies in Taiwan that began in 1991 have shown that degradable PE films can help lessen the problem of plastic wastes in agriculture. The starch content of degradable PE films is a major factor in their degradability.[153]

Degradation Rate The degradation rate was influenced by the mulching date, content of starch incorporated into the films, and the type of soil.[153]

Macro- and micro-environmental changes in different seasons affect the degradation time of the tested degradable plastic films. The bio/photodegradable silver-black colored PE films containing 20% starch from USI Far East Corporation degraded after 56, 83, 38, and 33 days when they were used as mulch in autumn (October 1991), winter (December 1991), spring (April 1992), and summer (August 1992), respectively. The greater the amount of starch incorporated, the faster the films degraded.[153] The degradation rate reached 93.5% for biodegradable films buried in slate alluvial soil, but it was less for films buried in red soil.[153]

264

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 56-1. Degradation of Various Mulching Films after Exposure to Natural Solar Radiation at Different Periods[153] % of Fracture Mulching Films

in Films (%)

Days from Mulching to Appearance of

IUPEC Bio Multi B Eco Green B Cell Green multi Kiemaru ECM Novon

(B) (B) (B) (B) (B) (B) (B)

1.89 3.33 18.5 3.13 3.77 3.70 80.8

Crack in Film 47 45 31 30 47 43 12

Plastor #221 Plastor #131 Plastor #19 Plastor #12 Green choice Ecolene Mater-Bi Regular PE

(P) (P) (P) (P) (D) (D) (B)

61.4 0.49 0.55 1.36 25.3 0.72 48.7 0

20 46 68 46 20 60 52 —

Ecolene

(D)

1.01

0

Green choice Neogreenpol Novon Recycle paper Paper film Regular PE

(D) (B) (B) (B) (B)

66.6 40.1 83.9 48.1 21.3 0

19 13 14 30 32 —

Bioflexs

(B)

67.0

1

Green choice Paper film Recycle paper Cascades (paper) Young-1 Young-3 Regular PE

(D) (B) (B) (B) (B) (B)

50.7 15.3 11.9 22.5 25.1 35.7 0

9 16 16 58 16 16 —

Paper film

(B)

14.6

7

Recycled paper Polystarch Green choice Oligostarch Ecolence Regular PE

(B) (D) (D) (D) (D)

48.0 0.08 23.5 2.02 0 0

77 77 11 68 — —

Ecostorplus

(D)

4.96

30

KK film Recycle paper Regular PE

(D) (B)

73.1 6.8 0

19 22 —

Ecolene

(D)

100

—

Ecostrplus KK-1 KK-2 Polymer-M Regular PE

(D) (D) (D) (P)

86.5 100 100 0 0

—

Ecostarplus

(D)

65.8

—

Ecostar (D) 35.3 Plastor-132b (P) 11.2 Polygrade (P) 25.7 Regular PE 0 P, photodegradable; D, disintegradable; B, biodegradable.

Mulching Investigation

8/9/2000–18/12/2000

30/9/1999–30/12/1999

04/11/1998–01/02/1999

11/10/1997–02/02/1998

08/11/1996–16/2/1997

27/10/1995–29/12/1995

5/12/1994–10/2/1995 — — — — — — —

9/10/1993–15/3/1994

265

56: Biodegradable Polyethylene Films Table 56-2. Days From Mulching to Appearance of Fracture in Film[153] Mulching Date

Days from Mulching to Appearance of Fracture in Film*

Air Temp (◦ C)

Total Sunshine (hrs)

Cumulative Light Energy (g/cal/cm2 )

9 October 1991

56

23.2

267.1

14,077

30 December 1991

83

18.5

415.5

20,803

28 April 1992

38

26.2

224.2

12,000

3 August 1992

33

28.9

173.6

11,198

*Data obtained from Photo/biodisintegradable PE films incorporated with 20% starch.

Table 56-3. Degradation of Mulching Films Incorporated with Different Starch Content[153] % of Fracture in Film

Starch Content Incorporated in Film (%)

First Crop*

Second Crop†

5%

11.2

15.1

10%

17.8

26.9

15%

20.6

25.1

20%

28.4

41.5

0

0

Regular *19 August–9 October 1992. † 29 December 1992–4 May 1993.

Graph 56-1. Weight Loss of Mater-Bi Biodegradable Film after Burying in Various Soils.[153]

Weight Loss in Film (%)

100.0

Slate alluvial soils 50.0 Sandstone-shale alluvial soil

Red sils 0.0

30

45

Days after Burying

60

266

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 56-2. Elongation Retained after Xenon Weatherometer Exposure of Starch-Modified Low Density Polyethylene (LDPE) Film.

Graph 56-3. Elongation Retained after Composting of Starch-Modified LDPE Film.

56: Biodegradable Polyethylene Films

Graph 56-4. Starch Content Retained after Burial of Ecostar Starch-Modified PE Film.

267

Chapter 57

Starch Synthetic Resin Alloy Category: Biodegradable plastic.

Biodegradability

General Properties: Novamont Mater-Bi™ contains starch (nongenetically modified) blended with petroleum-based biodegradable polymers (e.g. polycaprolactone, which provides water resistance and strength). Mater-Agro is an entirely biodegradable film that, with the action of microorganisms under aerobic conditions and with suitable humidity, biodegrades completely, changing into water and carbon dioxide.[156]

Biodegradability is a characteristic of natural substances and materials being assimilated by microorganisms and thus introduced into the natural cycles. When natural organic materials go into the ground, they tend to decompose progressively and finally disappear.[156]

Chapter 58

Thermoset Polyester Category: Thermoset, polyester. General Properties: Thermoset polyesters, or unsaturated polyesters (UPES), are extremely versatile materials. Polyester coatings are suitable for outdoor use where considerable amount of sunlight is present. They have good weathering and mechanical properties.[157] Thermosetting powders are primarily composed of relatively high molecular weight solid resins and a cross-linking agent. Thermoset powders are used for a wide variety of decorative and protective applications.[158]

Polyester Powder Polyester resins are used to formulate urethane polyesters and polyester triglycidyl isocyanurate materials.[158]

Urethane Polyesters Urethane-cured polyester powders have excellent resistance to outdoor environments. A smooth,

thin film that resists weathering and physical abuse makes the urethane polyesters a popular finish for high quality products.[158] Polyesters are generally less sensitive to physical degradation from UV light than aromatic urethanes, or two-component epoxies.[159]

Weathering Properties: UV Stabilization With UV light exposure, UPES undergo color change, loss of gloss, cracking, and other UVinduced deterioration. The UPES manufacturing process employs two different kinds of curing systems: the hot cure and the cold cure. In the hot cure system, the use of a combination of Ciba Tinuvin® 328 and Ciba Chimassorb® 81 provides good color stability to UPES after exposure to long-term weathering conditions.[160]

272

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Graph 58-1. Yellowness Index after Xenon Arc Weathering of Unsaturated Polyester.[160] 25 Control 20

Yellowness Index

0.3% Chimassorb 81 15

10

0.15% Tinuvin 238 0.15% Chimassorb 81

5

0

0

1000

2000

3000

Exposure Time (hrs) Note: Xenon Arc Weathering, ISO 4892-2, dry; UPES prepared by hot curing.

4000

Chapter 59

Polyurethane Reaction Injection Molding System Category: Polyurethane, thermoset. General Properties: Reaction injection molding (RIM) takes its name from a chemical reaction that occurs within the forming tool. The plastics end up as thermosets, either polyurethanes or foamed polyurethanes. The two components that produce the polyurethane are mixed just prior to injection into the tool.[161] Recticel Colo-Fast® is a light- and heat-stable polyurethane designed for RIM technology. Based on aliphatic isocyanates, Colo-Fast® is integrally colored and does not require post-painting or in-mold coating to prevent UV degradation of the exposed polyurethane.[162]

Weathering Properties Colo-Fast® LM 161 has been subjected to a number of artificial weathering (e.g., weatherometer) tests as well as outdoor exposure in Florida. Typically, there is a slight increase in gloss of a medium gloss sample in most tests without polishing the sample. This is due to smoothing of the tiny irregularities in the surface (faithfully reproducing the mold texture) which gave the sample its original medium gloss level. On extremely long exposure,

longer than required by automotive specifications, there is some dulling of the surface, but this can be restored by polishing with common automotive cleaners. No waxing is needed.[163] After artificial exposure there is little change in gloss even without washing or polishing. Gloss increases slightly in samples exposed for nine months in Florida. These samples must be washed to remove the dirt that accumulates under outdoor conditions. No surface cracking or discoloration was observed after artificial weathering or Florida exposure.[163] Samples without pigment have also been exposed to artificial weathering conditions. Even without pigment, the samples show only slight discoloration and gloss change, demonstrating the material’s inherent weatherability.[163] EMMAQUA (referred to as Sun 10 Testing by Recticel) testing was conducted on Colo-Fast® RIM polyurethane and several competitive materials. After the equivalent of five years of outdoor weathering, the materials were compared visually on a scale of 10 (best) to 1 (poor). Colo-Fast® remains unchanged with a rating of 10 out of 10 for the entire test. After just three years, the PVC samples showed warping and after four years they were brittle. The stabilized aromatic rates 5 out of 10 after five years. The aromatic with in-mold coated (IMC) paint shows a wear rating of only 2 out of 10.[162]

274

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 59-1. Surface and Appearance Changes after Xenon Arc Accelerated Weathering Exposure (GM Specifications) of Recticel Colo-Fast® Polyurethane RIM System

59: Polyurethane Reaction Injection Molding System

275

Table 59-2. Surface and Appearance Changes after Xenon Arc Accelerated Weathering Exposure (Japanese Specifications) of Recticel Colo-Fast® Polyurethane RIM System

276

The Effects of UV Light and Weather on Plastics and Elastomers

Table 59-3. Surface and Appearance Changes after Fadeometer Accelerated Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System

Graph 59-1. Change in Color, b, after Florida Outdoor Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System and Aromatic Polyurethane.

59: Polyurethane Reaction Injection Molding System

277

Graph 59-2. Gloss Retained after QUV Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System.

Graph 59-3. Gloss Retained after Sunshine Carbon Arc Weathering Exposure of Recticel Colo-Fast® Polyurethane RIM System.

278

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 59-4. Results of Visual Inspection after EMMAQUA Accelerated Exposure of Recticel Colo-Fast® Polyurethane RIM System and Several Other Materials.[162]

Sun 10 Testing Visual Code

Colo-Fast

10

PVC Stabilized Aromatic

5

Aromatic IMC 0 Year 1

Year 2

Year 3

Year 4

Year 5

Note: EMMAQUA Fresnel-reflecting concentrator as per SAE J1961; total exposure: 1540 MJ/m2 (total UV 295–385 nm); 308 MJ/m2 = 1 equivalent Florida year; total: 838,000 langleys.

Chapter 60

Thermoplastic Elastomers: Overview Thermoplastic elastomers (TPEs) are a diverse family of rubber-like materials that, unlike conventional vulcanized rubbers, can be processed and recycled like thermoplastic materials. TPEs behave like elastomeric rubber at room temperature (i.e., durable and bouncy), but can also be melted and easily formed into shapes when they are heated like plastics. Thermo- means “heat” and plastic means “moldable.” Elastomer means “rubber.” So a TPE is a rubber material that can be molded when it is heated.[166] A TPE generally contains >50% elastomer. Most types of elastomers are difficult to process because they are cross-linked. But TPEs are rubbery without being cross-linked, making them easy to process.[166] Many TPEs are copolymers, a material made from two different constituents (monomers)—one of which is a rubber and the other a plastic. Because TPEs can be melted, they are recyclable. But because they form cross-links that are not permanent when they are cooled, this makes them rubbery.[166] There are two main kinds of TPEs, ionomers and block copolymers. An ionomer is a polymer that has a small number of ionic groups along its

backbone chain. A block copolymer is a polymer that has more than one section, or block. For example, a chain of SBS rubber is made of a short block of polystyrene followed by a longer block of polybutadiene, followed by another short block of polystyrene.[166] “The big difference between a cross-linked rubber and a thermoplastic elastomer is that in a crosslinked rubber the polymer chains are bonded to each other through covalent bonds, that is, the bonds that form when two atoms share a pair of electrons. In either type of thermoplastic elastomer, the polymer chains are held together by bonds that are weaker than covalent bonds. In the case of ionomers it is dipole-dipole interactions that bind the polymer chains to one another. In the block copolymer dispersion forces are at play. But in both ionomers and block copolymers, forces much weaker than those of the covalent bonding ‘cross-link’the polymer chains. Because much weaker forces are binding the chains together, breaking them apart is much easier, so easy that all it takes is the right amount of heat to separate the chains from each other, making the material processable again.”[167]

Chapter 61

Chlorinate Polyethylene Elastomer Category: Elastomer, thermoplastic, TPE. General Properties: Dow Chemical Company Tyrin® chlorinated polyethylene elastomer is often used as a modifier for PVC.[168]

Weathering Properties Modified PVC compounds made with Tyrin® show excellent resistance to weathering.[168]

Sunlight, ozone, and oxygen can commonly cause environmental degradation of many elastomers by attacking both saturated and (especially) unsaturated sites along the polymer chain. Because Tyrin products have a saturated molecular backbone, they are not as susceptible to such attacks as are many other elastomers.[169] Long-term exposures of properly formulated rubbers made with Tyrin elastomers have shown no cracking when tested in an ozone atmosphere or when exposed to outdoor weathering.[169]

Chapter 62

Olefinic Thermoplastic Elastomer Category: Elastomer, thermoplastic. General Properties: Thermoplastic olefins (TPOs) are generally <50% elastomer with common elastomer content between 10–30%. Advanced Elastomer Systems, LP, an Exxon Mobil Chemical Affiliate, offers Santoprene™ thermoplastic vulcanizates (TPVs), a series of highperformance elastomers combining the desirable characteristics of vulcanized rubber such as flexibility and low compression set with the processing ease of thermoplastics.[170] PolyOne Forprene® is the brand name of a family of compounds that consists of a polyolefin phase with a dynamically cured ethylene-propylene diene monomer phase closely dispersed in the polyolefin. This design gives unique rubber-like properties with the advantage of thermoplastic processing techniques.[171] Dow Chemical Company’s Engage™ thermoplastic elastomers are ethylene-octene copolymers produced via advanced Insite™ catalyst and process technology.[172]

Weathering Properties Forprene® has good resistance to ozone, UV radiation, and weathering exposure which is due to the saturated elastomeric phase.[171] Santoprene™ TPV black UV stable grades exhibit good retention of both physical and appearance properties after long exposure periods using many common weathering tests. Conventional Arizona Aging: Santoprene™ TPV black UV grades show a color change (E) of less than 3 for the 48-month exposure. The softer grades of general-purpose Santoprene TPV perform well during this exposure, but the harder grades show a continuous decrease in color stability with time.

The hardness change of these grades shows a slight deterioration over the same time period, the softer grades retaining their hardness. All of the materials tested maintained reasonably good tensile strength and elongation over the 48-month period.[173] Conventional Arizona Aging with Spray: Santoprene™ TPV black UV grades show a color change (E) of less than 3 for most grades for the 48-month period. The softer grades of Santoprene™ show minor hardness changes, while the harder grades continue to increase in hardness with exposure time. Most of the materials maintain a significant tensile strength during the exposure period. Both the black UV-stable and general-purpose grades of Santoprene™ maintain most of their elongation during exposure.[173] Conventional Florida Aging: Since Florida testing has a higher average humidity, the exposure is harsher on some materials. Humidity has a strong effect on the color of the harder grades of generalpurpose Santoprene™ TPV materials but a minor effect on black UV-stable grades, especially over long exposures. The hardness changes are minor, with the harder grades showing the most increase. Most of the materials maintain their tensile strength. The softer grades of general-purpose Santoprene™ TPV do not retain their elongation properties as well as the black UV-stable grades.[173] Conventional Florida Aging with Spray: The color change for black UV-stable grades of Santoprene™ TPV is very small. General-purpose (harder) grades of thermoplastic rubber have a large E. Significant hardness changes occur in the harder grades of general-purpose and black UV-stable grades. Softer grades exhibit only minor hardness changes. Tensile strength retention is good for most of the materials, Santoprene™ TPV general-purpose grades have a tensile strength retention rate similar to that of black

284

The Effects of UV Light and Weather on Plastics and Elastomers

UV-stable grades. General-purpose harder grades of Santoprene™ TPV show a continuous decrease in elongation with exposure time.[173]

Outdoor Accelerated Exposure Testing Equatorial Mount with Mirrors for Acceleration (EMMA): The general-purpose grades of Santoprene™ TPV show a greater color change than the black UV-stable grades. Most of the materials exhibit good retention of tensile strength with the exception of harder general-purpose Santoprene™ TPV grades which show minor deterioration. Elongation of harder grades of general-purpose Santoprene™ TPV exhibits significant deterioration during the exposure period. Soft general-purpose and UV-stable grades continue to retain elongation properties.[173] Equatorial Mount with Mirrors for Acceleration Plus Water (EMMAQUA): This exposure is the harshest. Softer, black UV-stabilized grades are the only materials that show minor changes in color. The rest of the materials show major color changes. The hardness change of most materials is minor. All the materials suffer a significant loss

in tensile strength. The general-purpose grades of Santoprene™ TPV do not retain their tensile strength as well as the black UV-stable grades. Elongation retention is very difficult for the harder grades of Santoprene™ TPV. The softer grades have better retention of elongation.[173] Xenon Arc: Most UV grades of Santoprene™ TPV retain 90% or more of their tensile properties after 3000 hours and 80% or more after 5000 hours. The harder grades of general-purpose Santoprene™ TPV show a significant color change with exposure level. The rest of the materials have a color change (E) of less than 3. Only minor changes in hardness are seen with increased exposure. Retention of tensile strength is good for all materials. Black UV-stable Santoprene™ TPV has increased tensile strength retention when compared to the generalpurpose grades. Santoprene™ TPV grades show good elongation. The color retention for the softer black UV-stable grades is excellent up to 2500 kJ/m2 . The hardest grade of this material, 123-50, shows significant color change with exposure.[173] Xenon Arc SAE J1960: Most Santoprene™ TPV black high-flow grades exhibit good retention of physical and appearance properties after 2500 kJ/m2 exposure to exterior automotive xenon arc testing.[174]

285

62: Olefinic Thermoplastic Elastomer

Weathering Properties by Material Supplier Trade Name Table 62-1. Retention of Mechanical Properties after Xenon Arc Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-67

121-73

121-80

67

73

80

Shore D Hardness Exposure Conditions Exposure Time (hrs)

Xenon Arc Exposure, SAE J1885 3000

5000

3000

5000

3000

5000

Tensile Strength

91

83

78

73

81

74

Elongation

98

93

75

72

78

74

100% Modulus

107

110

105

102

102

97

PROPERTIES RETAINED (%)

MATERIAL CHARACTERISTICS Grades

121-87

Shore A Hardness

123-50

40

50

87

Shore D Hardness Exposure Conditions Exposure Time (hrs)

123-40

Xenon Arc Exposure, SAE J1885 3000

5000

3000

5000

3000

5000

Tensile Strength

88

87

94

96

92

95

Elongation

89

84

92

89

93

91

100% Modulus

99

104

99

109

105

107

PROPERTIES RETAINED (%)

286

The Effects of UV Light and Weather on Plastics and Elastomers

Table 62-2. Material Properties after Arizona Outdoor Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

Exposure Conditions

Arizona Outdoor Exposure, SAE J1545

Hardness Test Method

ASTM D2240

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-67

121-73

121-80

121-40

101-64

67

73

80

40

64

Shore D Hardness

103-40

40

COLOR CHANGE (E) 6 months

3.6

4.6

1.6

0.3

5.2

3

12 months

2.9

3.3

1.1

1.4

3.1

7.3

24 months

1.4

2

1.4

2.7

1.7

8.3

48 months

1.2

1.6

1.7

2.8

1.5

11.9

−1

2

3

CHANGE IN HARDNESS Shore A (6 months) Shore D (6 months) Shore A (12 months)

5 −1

3

5

Shore D (12 months) Shore A (24 months)

4 2

6 −1

−1

4

Shore D (24 months) Shore A (48 months)

2

3 3

5 1

4

6

Shore D (48 months)

3 3

10

8

TENSILE STRENGTH RETAINED (%) 6 months

88

85

80

97

75

95

12 months

83

78

77

94

74

98

24 months

87

79

76

99

75

92

48 months

76

77

63

97

75

96

6 months

83

84

80

94

69

95

12 months

84

81

79

92

72

95

24 months

86

80

75

98

74

91

48 months

93

83

77

94

73

94

ELONGATION RETAINED (%)

287

62: Olefinic Thermoplastic Elastomer

Table 62-3. Material Properties after Arizona Outdoor Exposure with Spray for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

Exposure Conditions

Arizona Outdoor Exposure with Spray, SAE J1545

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

Hardness Test Method

ASTM D2240

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-67

121-73

121-80

121-40

101-64

67

73

80

40

64

Shore D Hardness

103-40

40

COLOR CHANGE (E) 6 months

−1

4

3

5

1

3

12 months

−1

−4

4

5

1

1

24 months

−1

2

5

6

2

2

4

5

9

2

7

4

3

48 months CHANGE IN HARDNESS Shore A (6 months)

−1

Shore D (6 months) Shore A (12 months)

5 −1

−1

4

Shore D (12 months) Shore A (24 months)

1 3 2 5

−1

−1

4

Shore D (24 months)

1 1

5

Shore A (48 months)

4

5

Shore D (48 months)

3 2

9

7

TENSILE STRENGTH RETAINED (%) 6 months

83

58

76

96

74

92

12 months

89

77

76

97

77

93

24 months

90

82

79

101

70

97

84

80

100

75

99

48 months ELONGATION RETAINED (%) 6 months

77

75

79

87

72

93

12 months

88

78

82

85

74

91

24 months

89

82

83

96

73

97

87

87

98

76

97

48 months

288

The Effects of UV Light and Weather on Plastics and Elastomers

Table 62-4. Material Properties after Florida Outdoor Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

Exposure Conditions

Florida Outdoor Exposure

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

Hardness Test Method

ASTM D2240

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-67

121-73

121-80

67

73

80

Shore D Hardness

123-40

101-64

103-40

64 40

40

COLOR CHANGE (E) 6 months

5.4

5.6

2.3

1.2

6.3

2.7

12 months

4.8

5

2.1

0.9

4.4

9.1

24 months

1.1

1.5

0.4

0.9

1.2

11.2

48 months

1

1.3

2.4

3.2

1.7

11.7

−2

1

4

CHANGE IN HARDNESS Shore A (6 months) Shore D (6 months) Shore A (12 months)

4 −2

1

2

Shore D (12 months) Shore A (24 months)

2 1

6 0

−3

5

Shore D (24 months) Shore A (48 months)

0

3 2

9 1

3

3

Shore D (48 months)

8 1

7

5

TENSILE STRENGTH RETAINED (%) 6 months

89

82

84

97

78

98

12 months

93

85

81

97

80

97

24 months

82

81

78

98

69

95

48 months

93

88

87

96

73

98

6 months

87

86

88

98

78

100

12 months

92

87

83

99

80

96

24 months

80

86

84

96

75

97

48 months

96

93

92

94

78

99

ELONGATION RETAINED (%)

289

62: Olefinic Thermoplastic Elastomer

Table 62-5. Material Properties after Florida Outdoor Exposure with Spray for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

Exposure Conditions

Florida Outdoor Exposure with Spray

Hardness Test Method

ASTM D2240

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-67

121-73

121-80

67

73

80

Shore D Hardness

123-40

101-64

103-40

64 40

40

COLOR CHANGE (E) 6 months

3.2

3.9

1.4

1.5

6.6

4.8

24 months

3

3.4

6.5

1.3

2.6

8.5

48 months

1.8

1.6

2.1

2.6

1.43

16.2

0

3

4

CHANGE IN HARDNESS Shore A (6 months) Shore D (6 months) Shore A (24 months)

4 1

2

5

Shore D (24 months) Shore A (48 months)

0 0 1 9

1

4

3

Shore D (48 months)

7 3

8

7

TENSILE STRENGTH RETAINED (%) 6 months

89

77

84

99

79

96

24 months

85

81

80

101

71

97

48 months

93

84

87

103

71

65

6 months

90

80

89

99

83

98

24 months

86

82

82

97

69

97

48 months

93

86

90

100

75

48

ELONGATION RETAINED (%)

290

The Effects of UV Light and Weather on Plastics and Elastomers

Table 62-6. Material Properties after EMMA Accelerated Exposure with Spray for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

Exposure Conditions

EMMA Accelerated Exposure, SAE J1545

Hardness Test Method

ASTM D2240

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-73

123-40

73

Shore D Hardness

101-73

103-40

73 40

40

COLOR CHANGE (E) 6 months

3.4

8.3

5.8

15

12 months

2.3

8.9

5.5

14.6

24 months

2.5

8.7

5.2

12.2

CHANGE IN HARDNESS Shore A (6 months)

2

Shore D (6 months) Shore A (12 months)

7 2

Shore D (12 months) Shore A (24 months)

8 3 5 5

−3

Shore D (24 months)

3 5

3

2

TENSILE STRENGTH RETAINED (%) 6 months

82

94

82

86

12 months

85

100

84

82

24 months

95

101

85

58

6 months

72

80

67

69

12 months

81

79

67

65

24 months

52

76

50

6

ELONGATION RETAINED (%)

291

62: Olefinic Thermoplastic Elastomer

Table 62-7. Material Properties after EMMAQUA Accelerated Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

Exposure Conditions

EMMAQUA Accelerated Exposure, SAE J1545

Hardness Test Method

ASTM D2240

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-73

123-40

73

Shore D Hardness

101-73

103-40

73 40

40

COLOR CHANGE (E) 6 months

3.6

9.5

6.8

15

12 months

3

8.4

5.5

14.9

24 months

2.1

7.3

5.2

9.5

CHANGE IN HARDNESS Shore A (6 months)

3

Shore D (6 months) Shore A (12 months)

5 4

Shore D (12 months) Shore A (24 months)

7 2 5 7

−5

Shore D (24 months)

2 4 −3

0

TENSILE STRENGTH RETAINED (%) 6 months

88

98

87

88

12 months

87

114

90

75

24 months

55

31

57

11

6 months

85

82

77

75

12 months

66

73

62

61

24 months

68

2

49

1

ELONGATION RETAINED (%)

292

The Effects of UV Light and Weather on Plastics and Elastomers

Table 62-8. Material Properties after Xenon Arc Exposure for Black UV Grades of Advanced Elastomer Systems Santoprene™ TPV Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

Black UV Grades

Reference Number

173

Exposure Conditions

Xenon Arc Exposure, SAE J1885

Hardness Test Method

ASTM D2240

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-67

121-73

121-80

67

73

80

Shore D Hardness

123-40

101-64

103-40

64 40

40

COLOR CHANGE (E) 3000 hrs

1.5

2

2.3

2.7

7.8

5.3

5000 hrs

2

2.1

6.5

2.1

2.5

9.5

3

2

4

CHANGE IN HARDNESS Shore A (3000 hrs) Shore D (3000 hrs) Shore A (5000 hrs)

1 5

2

2

5

Shore D (5000 hrs)

3 1

7

3

TENSILE STRENGTH RETAINED (%) 3000 hrs

91

78

81

94

61

88

5000 hrs

83

73

74

96

64

84

3000 hrs

98

75

78

93

57

88

5000 hrs

93

72

74

90

67

84

ELONGATION RETAINED (%)

293

62: Olefinic Thermoplastic Elastomer

Table 62-9. Material Properties after Xenon Arc SAE J1960 Exterior Automotive Testing for Advanced Elastomer Systems Santoprene™ TPV High-Flow Grades Material Family

Olefinic Thermoplastic Elastomer Advanced Elastomer Systems Santoprene™ TPV

Material Supplier Features

High-Flow Grades

Reference Number

173

Exposure Conditions

SAE J1960 Exterior Automotive

Hardness Test Method

ASTM D2240

Tensile Strength Test Method

ASTM D412

Elongation Test Method

ASTM D412

Color Test Method

SAE J1545

MATERIAL CHARACTERISTICS Grades Shore A Hardness

121-50 M100

121-62 M100

121-75 M100

50

62

75

COLOR CHANGE (E) 600 kJ/m2

0.7

0.8

0.9

kJ/m2

1.0

0.4

1.3

1800 kJ/m2

0.7

1.3

1.2

2500 kJ/m2

2.4

1.8

1.8

600 kJ/m2

2

3

4

1240 kJ/m2

3

4

5

1800 kJ/m2

2

5

4

kJ/m2

2

4

5

600 kJ/m2

12

11

8

1240 kJ/m2

12

16

5

1800 kJ/m2

14

21

11

kJ/m2

11

19

7

600 kJ/m2

14

13

10

1240 kJ/m2

12

22

7

1800

kJ/m2

12

26

12

2500

kJ/m2

7

24

12

1240

CHANGE IN HARDNESS (SHORE A)

2500

TENSILE STRENGTH (% LOSS)

2500

ELONGATION CHANGE (% LOSS)

294

The Effects of UV Light and Weather on Plastics and Elastomers

Table 62-10. Material Properties after UV-CON Accelerated Indoor Exposure of PolyOne Forprene® Olefinic Thermoplastic Elastomer

62: Olefinic Thermoplastic Elastomer

295

Table 62-11. UV Resistance after Accelerated UV Light Exposure of PolyOne Forprene® Olefinic Thermoplastic Elastomer

Table 62-12. Ozone Resistance of PolyOne Forprene® Olefinic Thermoplastic Elastomer

296

The Effects of UV Light and Weather on Plastics and Elastomers

Table 62-13. Ozone Resistance of Advanced Elastomer Systems Santoprene™ Olefinic Thermoplastic Elastomer

62: Olefinic Thermoplastic Elastomer

297

Table 62-14. Ozone Resistance of Dow Chemical Company’s Engage™ OlefinicThermoplastic Elastomer

298

The Effects of UV Light and Weather on Plastics and Elastomers

Table 62-15. Ozone Resistance of Advanced Elastomer Systems Santoprene™ Black Olefinic Thermoplastic Elastomer

Graph 62-1. Carbonyl Formation after Xenon Arc Weatherometer Exposure of Dow Chemical Company’s Engage™ Olefinic Thermoplastic Elastomer.

62: Olefinic Thermoplastic Elastomer

299

Graph 62-2. Decrease in Molecular Weight after Xenon Arc Weatherometer Exposure of Dow Chemical Company’s Engage™ Olefinic Thermoplastic Elastomer.

Chapter 63

Polyester Thermoplastic Elastomer Category: Polyester, thermoplastic, elastomer, TPE, TP. General Properties: DuPont Hytrel® thermoplastic polyester elastomers are block copolymers consisting of a hard (crystalline) segment of polybutylene terephthalate and a soft (amorphous) segment based on long-chain polyether glycols. Its properties are determined by the ratio of hard to soft segments and by the makeup of the segments. Hytrel® combines many of the most desirable characteristics of highperformance elastomers and flexible plastics. The various grades of Hytrel® exhibit a wide range of flexibility/stiffness and processing capabilities.[180]

Weathering Properties For outdoor applications, Hytrel® should be protected from UV attack. The most efficient method is the incorporation of low levels of carbon black. Where nonblack products are desired, weather protection is most efficiently obtained by incorporation of UV stabilizers alone (natural) or in combination with low levels of colored pigments.[181] Excellent resistance to degradation is observed in weatherometer and Florida aging studies with specimens 1.9 mm (0.075 ) thick and containing 0.5% and 1% carbon black. These levels of carbon black provide good protection for thick sections; for

thinner parts, additional protection is needed. For films 0.25 mm (0.010 ) thick, up to 3% carbon black is needed for protection from UV light.[181] Specimens 1.9 mm (0.075 ) thick behaved very well under weatherometer and Florida aging studies with as little as 0.5% black; little additional improvement is achieved with 1% carbon black. As sample thickness is decreased, however, higher levels of the protective additive are required. Tests indicate that 1.9% carbon black is required for excellent protection in 0.25 mm (0.010 ) thick films, with somewhat compromised property retention at lower thicknesses. Some tested compounds contained moisture stabilizing additives such as 1.9% polycarbodiimide in addition to carbon black, which undoubtedly compromises property retention as predicted for similar black compounds containing no polycarbodiimide.[181]

Weathering Properties: Color Pigments Hytrel® can be pigmented or colored using pigment concentrates or masterbatches as pellet-pellet blends with the virgin polymer. Other techniques such as liquid colorants and dusting-on of powdered pigments have also been used. Hytrel® has also been colored by dipping in liquid dye baths.[181]

302

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 63-1. Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for DuPont Hytrel® Polyester Thermoplastic Elastomer

63: Polyester Thermoplastic Elastomer

303

Table 63-2. Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for DuPont Hytrel® 40D Polyester Thermoplastic Elastomer with Carbon Black

304

The Effects of UV Light and Weather on Plastics and Elastomers

Table 63-3. Material Properties Retained after Florida Outdoor Weathering for DuPont Hytrel® 5556 Polyester Thermoplastic Elastomer with Carbon Black

63: Polyester Thermoplastic Elastomer

305

Table 63-4. Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for Varying Thicknesses of DuPont Hytrel® 6345 Polyester Thermoplastic Elastomer Films with Carbon Black

306

The Effects of UV Light and Weather on Plastics and Elastomers

Table 63-5. Material Properties Retained after Carbon Arc Accelerated Weathering for DuPont Hytrel® 40D Polyester Thermoplastic Elastomer

63: Polyester Thermoplastic Elastomer

307

Table 63-6. Material Properties Retained after Carbon Arc Accelerated Weathering for DuPont Hytrel® 5556 Polyester Thermoplastic Elastomer with Varying Levels of Carbon Black

308

The Effects of UV Light and Weather on Plastics and Elastomers

Table 63-7. Material Properties Retained and Surface and Appearance after Carbon Arc Accelerated Weathering for DuPont Hytrel® HT-X-3803 and 4056 Polyester Thermoplastic Elastomers with Varying Levels of Carbon Black

63: Polyester Thermoplastic Elastomer

309

Table 63-8. Soil Burial and Fungus Resistance for DuPont Hytrel® Polyester Thermoplastic Elastomer

Chapter 64

Polystyrene-Butadiene-Styrene Thermoplastic Category: Styrene-butadiene, thermoplastic. General Properties: Polystyrene-butadiene-styrene (SBS) is a hard rubber, a type of copolymer called a block copolymer. Its backbone chain is made up of three segments. The first segment is a long chain of polystyrene, the middle segment is a long chain of polybutadiene, and the last segment is another long section of polystyrene. BASF Styrolux® is a styrene-butadiene block copolymer.[184]

Weathering Properties Styrolux® has effective stabilization to inhibit aging on exposure to oxygen and high temperatures. In diffuse light, parts made from Styrolux® retain their optical and mechanical properties for

many years. However, in outdoor applications the material can be degraded by the high energy content of sunlight, resulting in yellowing and deterioration of mechanical properties. Styrolux® is not recommended for outdoor applications. The time to onset of yellowing can be considerably prolonged by using UV stabilizers.[184] UV-stabilized Styrolux® 656 C was tested next to unstabilized Styrolux® 656 C in a Xenotest 1200 under the conditions of DIN 53387—a filter system corresponding to solar radiation, a black panel temperature of 45◦ C, a relative humidity of 65%, and a dry period of 102 minutes in the cycle. The UV-stabilized material began to show visible color change after 60 days of exposure, and after 120 days the sample was a very dull yellow. The unstabilized Styrolux® 656 C showed visible color change after 14 days of exposure, and after 120 days the sample was bright yellow.[185]

Chapter 65

Styrenic Thermoplastic Elastomer Category: Thermoplastic, elastomer. General Properties: Kraton® D and G polymers are styrenic block copolymers (SBCs) based on the feedstocks styrene, butadiene, and isoprene. Kraton® D polymers have polybutadiene or polyisoprene midblocks that provide ultimate elasticity and flexibility. Kraton® G polymers are SBCs with a fully saturated midblock. They are elastic and flexible with the additional benefits of enhanced oxidation and weather resistance.[186] Laporte AlphaGary Evoprene® G material is a styrene-ethylene-butylene-styrene block copolymer with a fully saturated midblock (i.e., no double bonds) giving excellent ozone and UV resistance.

Weathering Properties Kraton® D series rubbers are unsaturated and are therefore susceptible to attack by oxygen, ozone, and UV radiation, especially when stressed. Degradation is evidenced by surface crazing and hardening, or major cracking. Stabilizers should be added to the formulation to protect the material throughout processing and throughout its service life.[187] Kraton® D rubbers contain an unsaturated rubber midblock which is similar to natural rubber or SBR in its resistance to degradation. The two types of rubber midblocks—polybutadiene and polyisoprene— in Kraton® D series rubbers behave differently when attacked by oxygen, ozone, or UV radiation. Polybutadiene (Kraton® SBS rubbers) tends to cross-link with film, becoming hard and brittle. Polyisoprene (Kraton® SIS rubbers) tends to undergo chain scission, whereby films become soft and tacky. Blends of the two types show less change on aging than either type alone.[187] Kraton® G Polymer compounds exhibit good ozone resistance and can withstand prolonged outdoor exposure applications.[186] They contain a low level of phenolic antioxidant. Kraton® G rubbers have a saturated, olefin rubber type centerblock and

thus have good resistance to degradation. When properly formulated, they have the ability to withstand 4000 hours of weatherometer exposure with minimal change in properties. They will also pass ozone chamber testing without cracking or degradation of properties. Although the stability of these polymers is much better than that of the Kraton® D series rubbers, it is good practice to include additional stabilizers.[187] Kraton® G 1000 and G 4000 polymers can offer enhanced oxidation and weather resistance.[186] The results of bothASTM 1171 andASTM D518 ozone testing indicate that Kraton® rubber exhibits outstanding resistance to ozone.[176] All Evoprene® G compounds have excellent UV resistance when pigmented black, but some grades require extra stabilization when used in light or natural colors. Evoprene® G shows no cracks when ozone tested (100 pphm/200 hours/20% strain) and excellent UV resistance (1500 hours @ 40◦ C QUV (black)).[188]

Weathering Properties: Stabilization In choosing a stabilizer package for Kraton® materials, it should be noted that the rubber network is more susceptible to attack than the polystyrene domains. Thus it is best to use stabilizers that associate primarily with the rubber network.[187] One or more stabilizers should be added during compounding, at a level of about 0.5 phr. Ciba Tinuvin® P has been found to be effective at this level. A combination of 0.3 phr each of BASF Uvinul® 400 and Ciba Tinuvin® n 326 is particularly effective for most products, although it can cause discoloration in white stocks. With opaque products, even without UV stabilizers, the addition of up to five parts of a reflective filler such as titanium dioxide or a light-absorbing filler such as carbon black gives excellent protection.[187]

314

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 65-1. Ozone Resistance of Kraton® Styrenic Thermoplastic Elastomer

Chapter 66

Urethane Thermoplastic Elastomer Category: Elastomer, polyurethane, thermoplastic. General Properties: Dow Chemical Pellethane® 2103-80 AEF elastomer is a polytetramethylene glycol ether-based polyurethane elastomer or urethane thermoplastic elastomer.[189] The Noveon Estane® 58202, Estane® 58300, Estane® 58315, and Estane® 58863 thermoplastic polyurethane elastomers (TPUs) are polyether-based urethane thermoplastic elastomers.[190]

Weathering Properties TPUs are known to have poor color stability when exposed to UV light. Pellethane® TPU resins are based on aromatic isocyanates which absorb UV radiation. In turn, this can cause the material to become yellow. Depending on thickness, the material may embrittle in very thin films. Degradation upon UV exposure tends to limit the use of TPUs in outdoor applications without the use of stabilizers.[190] Studies have supported two mechanisms for photodegradation in methylenediphenyl diisocyanate (MDI) based polyurethanes involving photo-oxidation of the aromatic isocyanate and direct photolytic cleavage of the urethane group. Photo-oxidation of the aromatic isocyanate may produce a diquinone imide. Quinone imides are primarily responsible for the rapid yellowing of MDI polyurethane. Subjecting aromatic radicals to oxygen results in the formation of semi-quinone groups, which have strong UV absorption and act as a photostabilizing surface layer that protects the bulk polymer.[18] Degradation can also be caused by direct photolytic cleavage of the urethane group, which can occur in the absence of oxygen. It has been shown that this cleavage of the urethane group can result in a photo-Fries rearrangement. Further photochemistry

of the aromatic amine photo-Fries product can lead to the formation of colored azo products, which accounts for the photo-induced yellowing in the absence of oxygen. Similar to the semi-quinone and quinone groups, the photo-Fries product is also an efficient UV absorber and is capable of acting as an internal filter to inhibit subsequent photooxidation. When irradiated in air, the distribution between photo-Fries products was found to be wavelength dependent, with the photo-Fries product being dominant at wavelengths below 330–340 nm.[7] Marked property loss is not always observed when aromatic TPUs are exposed to UV light. This is due to the equal probability of chain scission and radical recombination processes upon oxidation of the aromatic urethanes.[7] In one study, infrared analysis of UV-exposed ester-based urethanes showed substantial loss of aromatic structures, urethane structures, and methylene group content. The samples had yellowed and lost tensile properties upon UV exposure. The polyester component was found to be more photostable than the MDI component.[7] On the other hand, the polyether soft segment is not as stable under UV exposure as the polyester-based segments. Studies showed that TPUs made using polyester macroglycols maintain properties better after UV exposure than those made with polyether glycols. This study also showed that thicker samples are less affected by UV radiation, due to limited surface exposure.[7] An aliphatic polyurethane containing a polyether soft segment also underwent rapid photodegradation with catastrophic loss of molecular weight after a short xenon arc exposure of only 231 hours. FTIR analysis confirmed that it was the polyether component that degraded. Numerous other studies support the degradation effects on polyether urethanes due to oxidation and the improved resistance to oxidation of polyester urethanes.[7]

316

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties: UV Stabilization Two methods of UV stabilization are commonly used: UV absorbers (e.g., benzotriazole) and UV stabilizers (e.g., hindered amines). Hydroxybenzotriazoles preferentially absorb light in the 300–400 nm wavelength range. They dissipate the light energy by a tautomeric process, which protects the polymer by preventing it from absorbing harmful radiation. Hindered amines, on the other hand, act as radical scavengers. Through the formation of nitroxyl radicals, hindered amines terminate and deactivate alkyl radicals and peroxy radicals, which are known to participate in the photo-oxidation process. While functioning as radical scavengers, the stabilizing species (the nitroxyl radical) is regenerated and continues to scavenge.[7] Antioxidants are also commonly used to aid in UV stabilization. Although antioxidants are neither light stabilizers nor UV absorbers, they often improve the overall weatherability of the TPU when used in combination with a UV absorber or

light stabilizer. They do this by interrupting the free-radical process during photo-oxidation.[7] It is also very common to color the resin black and add components for UV stabilization. Yellowness and change in physical properties for Pellethane® 2103-80AEF resins were measured after exposure to QUV light. UV stabilizers, both a benzotriazole and a hindered amine, were added at a UV stabilizer level of 0.25% and 0.5%, respectively. The addition of the UV stabilizers does reduce the rate and extent of yellowing in Pellethane® 2103-80 AEF resins. Despite the color development, Pellethane® 2103-80 AEF resins maintain physical strength to a considerable extent after QUV exposure. With no stabilizer, there is about 30% loss of tensile strength and elongation after 2000 hours of exposure. With stabilizers, the loss is less than 10%. In another QUV study it was found that neither a UV absorber nor a light stabilizer alone was sufficient to retard discoloration and retain good physical properties. However, synergism did occur when the two were blended together and used as a package.[7]

66: Urethane Thermoplastic Elastomer

317

Weathering Properties by Material Supplier Trade Name Table 66-1. Properties Retained after Fadeometer Accelerated Weathering for Noveon Estane® 58202 and Estane® 58300 Urethane Thermoplastic Elastomer

318

The Effects of UV Light and Weather on Plastics and Elastomers

Table 66-2. Properties Retained after Fadeometer and QUV Accelerated Weathering for Noveon Estane® 58315 Urethane Thermoplastic Elastomer

66: Urethane Thermoplastic Elastomer

319

Table 66-3. Properties Retained after Fadeometer Accelerated Weathering for Noveon Estane® 58315 and Estane® 58863 Urethane Thermoplastic Elastomer

320

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 66-1. Elongation after QUV Exposure of Dow Pellethane® 2103-80 AEF Urethane Thermoplastic Elastomer.

Graph 66-2. Tensile Strength after QUV Exposure of Dow Pellethane® 2103-80 AEF Urethane Thermoplastic Elastomer.

66: Urethane Thermoplastic Elastomer

321

Graph 66-3. Yellowness Index after QUV Exposure of Dow Pellethane® 2103-80 AEF Urethane Thermoplastic Elastomer.

Graph 66-4. Yellowness Index after QUV Exposure of BASF Elastollan® 1185A-10 Urethane Thermoplastic Elastomer.

322

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 66-5. Tensile Strength after Xenon Weatherometer Exposure of BASF Elastollan® 1185A-10 Urethane Thermoplastic Elastomer.

Chapter 67

Nitrile Thermoplastic Elastomers Category: Elastomer, TPE, thermoplastic.

Weathering Properties

General Properties: Eliokem Chemigum® NBR elastomers are copolymers of acrylonitrile and butadiene. They are used as elastomeric modifiers, especially in PVC.[193]

Chemigum® displays excellent resistance to outdoor weathering. After two years of exposure in Florida, both direct and under glass, Chemigum did not exhibit severe chalking, exudation, cracks, or unsightly blemishes on the surface.[194]

324

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 67-1. Material Properties after Florida Outdoor Weathering of Eliokem Chemigum® Nitrile Thermoplastic Elastomer

Chapter 68

Thermoset Elastomers or Rubbers: Overview Acrylic Rubber: An alkyl-acrylate copolymer that has good resistance to oxygen at normal and elevated temperatures, excellent ozone and weathering resistance, but poor moist heat resistance.[195] Butyl: Butyl was originally known as “the inner tube rubber.” Butyl is resistant to ozone and weathering. Chlorosulfonyl Polyethylene has excellent resistance to oxygen and ozone.[195] Ethylene-Propylene Copolymer is similar to styrene-butadiene rubber (SBR) but demonstrates improved resistance to atmospheric aging, oxidization, and ozone.[195] EPDM: The polymer of ethylene-propylene diene monomer is an ethylene-propylene terpolymer synthetic rubber that exhibits outstanding resistance to weathering, aging, ozone, and oxygen.[200] Fluorocarbon Elastomer: Fluorocarbons are the end product of the copolymerization of highly fluorinated olefins. Fluorocarbons are resistant to the effects of ozone, oxygen, and sunlight. Natural Rubber: This is nature’s main “readymade” contribution to the field of elastomers.

Its chief source is the Hevea brasiliensis, a commercially grown tree found principally in the Far East. Natural rubber does not age as well as many of the synthetics, and is inferior to the synthetic elastomers in its resistance to sunlight, oxygen, and ozone. Neoprene: Neoprene, chloroprene rubber, is a polymer of chloroprene and has several properties that are superior to natural rubber, including better resistance to sunlight, ozone, and oxidation.[196] Silicone Rubber: Silicone rubber is one of the versatile families of semi-organic synthetics known as silicones that look and feel like organic rubber, yet have a completely different type of structure than other elastomers. The backbone of the elastomer is not a chain of carbon atoms but an arrangement of silicon and oxygen atoms. Silicone elastomers show no molecular orientation or crystallization on stretching and must be strengthened using reinforcing materials. Silicone elastomers are resistant to oxygen and ozone, even at elevated temperatures.[196] SBR is a synthetic copolymer of styrene and butadiene. SBR provides good resistance to sunlight and ozone.

326

The Effects of UV Light and Weather on Plastics and Elastomers

Table 68-1. Comparison of Ozone Resistance and Weather Resistance for a Few Thermoset Elastomers[197] Material

Ozone Resistance

Weather Resistance

Nitrile

Poor

Fair

SBR

Poor

Fair

Good/excellent

Excellent

Ethylene Propylene

Excellent

Excellent

Fluorocarbon

Excellent

Excellent

Fluorosilicone

Excellent

Excellent

Polyacrylate

Excellent

Excellent

Polyurethane

Excellent

Excellent

Silicone

Excellent

Excellent

Neoprene

Chapter 69

Butyl Rubber, Bromobutyl Rubber, and Chlorobutyl Rubber Category: Thermoset, rubber.

5. Avoid clays, to the extent possible, especially hard clays. Calcium carbonates, talcs, and silicas generally perform better.

General Properties: Butyl rubber is a copolymer of isoprene (minor) and isobutylene. Exxon bromobutyl (BIIR), a brominated copolymer of isobutylene and isoprene, has a predominantly saturated backbone of butyl. Exxon chlorobutyl (CIIR), a chlorinated copolymer of isobutylene and isoprene, is an elastomeric isobutylene-isoprene copolymer (halogenated butyl) containing reactive chlorine. Chlorobutyl and bromobutyl contain 1.2% of the halogenated butyl. The halogen addition changes the cure characteristics and can improve adhesion.[198]

Isobutylene backbone polymers are generally susceptible to attack by UV radiation. In lightcolored compounds, this results in chain scission and the development of surface tack with high dirt retention. Carbon black-filled isobutylene polymer compounds have good weathering resistance to UV attack and weathering, in general, due to the masking and UV absorption effects of carbon black.[200]

Weathering Properties

Weathering Properties: Ozone Resistance

Butyl, bromobutyl, and chlorobutyl are resistant to aging, ozone, and weathering from atmospheric exposure.[198] Carbon black-filled bromobutyl compounds have high resistance to weathering. Light-colored compounds should be formulated to minimize degradation to UV light. The following techniques are suggested for maximum weather resistance in mineral-filler compounds.[199] 1. Obtain a high state of cure. 2. Use low levels of a high quality paraffinic plasticizer. 3. Include UV light absorbers such as titanium dioxide. 4. Depending upon the application, use up to 10 phr of paraffin wax to protect the surface.

The low level of chemical unsaturation in the butyl polymer chain produces an elastomer with greatly improved resistance to ozone when compared to polydiene rubbers (such as polybutadiene, polyisoprene, and styrene-butadiene rubbers). Butyl, with the lowest level of unsaturation, provides high levels of ozone resistance, which is also influenced by the type and concentration of vulcanizate cross-links. For maximum ozone resistance, as in electrical insulation, the least unsaturated butyl is advantageously used.[201] Bromobutyl shows good resistance to attack by ozone due to its high saturation. It is superior to general-purpose rubbers. High loadings of fillers and plasticizers are detrimental to ozone resistance, especially highly aromatic oils even at moderate levels. Amine, resin, thiourea, and alkylphenol disulfide cures of bromobutyl yield vulcanizates with high ozone resistance.[199]

Chapter 70

Chlorosulfonated Polyethylene Rubber Category: Elastomer, thermoset. General Properties: DuPont Elastomers Hypalon® chlorosulfonated polyethylene resists the damaging effects of weather, including UV and ozone.[98] •

Hypalon® 20: 29% chlorine content, 1.4% sulfur content

•

Hypalon® 30: 43% chlorine content, 1.1% sulfur content

•

Hypalon 40: 35% chlorine content, 1% sulfur content

•

Hypalon® 45: 24% chlorine content, 1% sulfur content

®

Weathering Properties Vulcanizates of this chlorosulfonated polyethylene synthetic rubber are highly resistant to ozone, oxygen, weather, heat, oil, and chemicals. Hypalon resists discoloration on exposure to light and is widely used in light-colored vulcanizates.[98] Hypalon® 40 is the most weather resistant type, and although the differences are small, they are enough to suggest that Hypalon® 40 can be used for outdoor applications where possible.[202] Ten-year test results on vulcanizates of Hypalon® 48 indicate that it sheds dirt better than Hypalon® 40.[202] Hypalon® 20 dissolves in solvents to give much lower solution viscosities (or higher solid content at equivalent viscosity) thus making it suitable for the preparation of weather resistant flexible films from solution. Hypalon® 30 offers low solution viscosities but is a much stiffer material.[202] Hypalon® 45, a more crystalline material, has sufficient strength to be used in the uncured state. Uncured compounds of Hypalon® 45 may actually benefit from exposure to the weather as a result of

gradual cross-linking promoted by UV exposure and moisture. Long-term exposure data demonstrates that, when properly compounded, Hypalon® 45 has excellent weathering resistance.[202]

Weathering Properties: Color Pigments The type and amount of pigments are critical because Hypalon® requires protection from UV light. Unpigmented compounds of Hypalon® darken and craze after six to twelve months of direct exposure to sunlight.[202] It is desirable to select only those color pigments that show a high degree of opacity to UV radiation. This restricts the penetration of UV radiation and the subsequent deterioration of the outermost surface where it is observed mainly as a loss of gloss rather than crazing. In addition, a pigment that protects the surface of a compound of Hypalon® from deterioration during outdoor exposure is of little value unless it also maintains its color.[202] The retention of color by vulcanizates of Hypalon® after exposure to weather varies considerably with the pigment used since all color pigments do not afford the same degree of color stability. It is important to remember that pigments differ in their color stability and opacity. Yellows and oranges are lower in tinctorial strength and durability than blues and greens. These differences are usually accentuated in pastels where orange and yellow fade much more rapidly than blue or green when used at the same ratio of color to titanium dioxide. Blends of color pigment and titanium dioxide are frequently used for purposes of economy and/or color match. Although adequate in mass tones, orange and yellow should not be used in very light tints where color stability is important.[202] A study was conducted on pigments specifically recommended for use in compounds of Hypalon® .

330

The Effects of UV Light and Weather on Plastics and Elastomers

Table 70-1. Color Pigments Recommended for Use in Hypalon® [202]

The recommended pigments were divided into four groups ranging from the most to the least efficient on a weight basis. The most efficient were those where the minimum suggested amount is 3 phr of Hypalon®. Compounds containing three parts have not crazed after ten years of exposure to direct sunlight in Delaware. The next group—mass tones of orange and yellow—is somewhat less efficient, requiring 6 phr. They have been exposed to direct Delaware sunlight for fifteen years without objectionable color change or crazing; but pastels of these colors are much less permanent. The third group consists of red iron oxide. Iron oxide is very stable but is less brilliant than organic pigments. Because of its low

tinctorial strength the minimum suggested amount is 10 phr. The last group contains titanium oxide, which is the only pigment satisfactory for use in Hypalon®. The most chalk-resistant rutile grades should be used unless a self-cleaning surface is desired; the suggested minimum is 35 phr.[202]

Weathering Properties: Curing Systems In nonblack stocks, magnesia/pentaerythritol is preferred except when maximum water resistance

331

70: Chlorosulfonated Polyethylene Rubber

is required. In such a case, tribasic lead maleate is satisfactory. If flexibility is important, no more than five parts of magnesia should be used. Vulcanizates containing high amounts of magnesia stiffen on exposure to weather. In black stocks, a litharge curing system is the most satisfactory.[202] The choice of curing systems depends primarily upon the requirements for color and water resistance. There are four curing systems from which to choose: magnesia, magnesia/pentaerythritol, litharge, and tribasic lead maleate. Compounds designated to be used uncured can be formulated using Hypalon® 45 as the base polymer.[202] Nonblack (Colored) Compounds: If maximum water resistance is not required, the compound may be cured with magnesia alone or with a magnesia/pentaerythritol combination. Compounds cured with either system have excellent colorability, and they retain their color and smooth surface during outdoor exposure. Of the two systems, the magnesia/pentaerythritol system is generally more useful. Compounds cured with twenty parts of magnesia have better abrasion resistance and retain color slightly better, but they are sometimes scorchy and stiffen noticeably upon exposure to weather. (If flexibility is important, magnesia content should not exceed five parts.) Compounds cured with magnesia/pentaerythritol generally exhibit greater processing safety and retain their flexibility on exposure to weather. Their color retention, if not quite the equal of an all magnesia-cured compound, is nevertheless excellent.[202] Litharge is the recommended curing agent. It is necessary if low water swell is required and is preferred even if water resistance is not required. Litharge-cured compounds are safe processing and have good physical properties. After fifteen-year exposure tests they show trace crazing and still retain flexibility.[202] The magnesia/pentaerythritol combination may be used if a black, lead-free compound is required without maximum water resistance. Compounds cured with magnesia/pentaerythritol are resistant to crazing and they retain their strength and flexibility when aged outdoors.[202] Hypalon® compounds retain much of their elongation during exposure to weather. It is also observed that the rate of elongation loss decreases with

time—most loss occurs in lightly loaded compounds. Compounds containing higher levels of black are more stable.[202]

Weathering Properties: Fillers Calcium carbonate is preferred as it chalks less than other fillers.[202] Several types of fillers are suitable for use in Hypalon®. Whiting is preferred from the viewpoint of weatherability alone; however, in many cases it is necessary to use other extenders for specific properties (e.g., water resistance) not obtainable with whiting. A summary of the performance of several commonly used fillers is given below.[202] Whiting (Calcium Carbonate): Vulcanizates containing 50 parts show trace crazing and moderate chalking after ten years of direct sun exposure in Delaware. White vulcanizates containing 200 parts have been exposed for eighteen months in Florida without surface deterioration. After fifteen years, mass tone green vulcanizates containing 150 parts whiting begin to chalk slightly and show trace crazing. Fine particle size precipitated calcium carbonate is entirely suitable for use in Hypalon® and often gives better physical properties. Since Hypalon® is not entirely dependent on pigment reinforcement, economic factors usually favor the use of ground whiting.[202] Clay (Aluminum Silicate): Yellow vulcanizates containing fifty parts of clay have shown excellent weather resistance.[202] Talc (Magnesium Silicate): Fading and chalking increase with increasing amounts of talc in colored compounds. Approximately 50 phr would be the maximum loading in white or light colors and 75 phr in black compounds.[202] Silica (Silicon Dioxide): Silica is not suggested as a primary filler as silica-filled vulcanizates have shown visible crazing after only one year in Florida.[202]

332

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties: Plasticizers Plasticizers have little influence on the craze resistance of vulcanizates of Hypalon® when used in moderate amounts (5–25 parts). No data are available on the durability of more highly plasticized formulations.[202]

Plasticizers have an influence on color stability. Aromatic and naphthenic oils discolor and should be avoided in light-colored stocks. Esters and chlorinated hydrocarbons show excellent color stability. Paraffinic oils are very stable, but their low order of compatibility with Hypalon® limits their usefulness.[202]

Weathering Properties by Material Supplier Trade Name Table 70-2. Material Properties Retained and Color Change after Outdoor Weathering and Accelerated Weathering of DuPont Elastomers Hypalon® Chlorosulfonated Polyethylene Rubber

70: Chlorosulfonated Polyethylene Rubber

333

Table 70-3. Material Properties Retained and Color Change after Arizona Outdoor Weathering for DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber

334

The Effects of UV Light and Weather on Plastics and Elastomers

Table 70-4. Material Properties Retained and Color Change after Florida and Delaware Outdoor Weathering for Wire Cable Compound DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber

70: Chlorosulfonated Polyethylene Rubber

335

Table 70-5. Surface and Appearance and Mildew Resistance after Texas and California Outdoor Weathering for Green Hose Cover Compound DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber

336

The Effects of UV Light and Weather on Plastics and Elastomers

Table 70-6. Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering for White DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber

70: Chlorosulfonated Polyethylene Rubber

337

Table 70-7. Material Properties Retained and Surface and Appearance after Delaware Outdoor Weathering for DuPont Elastomers Hypalon® 20 Chlorosulfonated Polyethylene Rubber

338

The Effects of UV Light and Weather on Plastics and Elastomers

Table 70-8. Material Properties Retained and Surface and Appearance after Panama Outdoor Weathering for Pond Liner Formulation DuPont Elastomers Hypalon® 45 Chlorosulfonated Polyethylene Rubber

70: Chlorosulfonated Polyethylene Rubber

339

Table 70-9. Material Properties Retained and Color Change after EMMA and EMMAQUA Accelerated Outdoor Weathering for Black DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber

340

The Effects of UV Light and Weather on Plastics and Elastomers

Table 70-10. Material Properties Retained and Color Change after Xenon Arc Weatherometer Exposure for Black DuPont Elastomers Hypalon® 40 Chlorosulfonated Polyethylene Rubber

70: Chlorosulfonated Polyethylene Rubber

341

Graph 70-1. Elongation at Break after Delaware Outdoor Exposure for DuPont Elastomers Hypalon® 20 Chlorosulfonated Polyethylene Rubber.

Chapter 71

Ethylene-Propylene Copolymer Category: Elastomer, thermoset. General Properties: Also known as ethylenepropylene rubber, or ethylene-propylene elastomer, Polimeri Dutral® is an ethylene-propylene copolymer.[205]

the carbon black it contains acts as an absorber, protecting items exposed to atmospheric agents and light for decades.[206] In the case of light-colored vulcanized items, it is advisable to attenuate the phenomenon with:[206] 1. high molecular weight Dutral®

Weathering Properties All ethylene-propylene elastomers are sensitive to light and UV rays. If the vulcanized part is black,

2. high purity paraffinic oils 3. zinc oxide, 15–20 phr 4. rutile titanium dioxide 5. phthalocyanine-based pigments

Weathering Properties by Material Supplier Trade Name Graph 71-1. Carbonyl Formation after Xenon Arc Exposure for Ethylene-Propylene Copolymer.

344

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 71-2. Decrease in Molecular Weight after Xenon Arc Exposure for Ethylene-Propylene Copolymer.

Chapter 72

Ethylene-Propylene Diene Methylene Terpolymer UV Resistance Ausimont Dutral-TER: All ethylene-propylene elastomers are sensitive to light and UV rays. If the vulcanized part is black, the carbon black it contains acts as an absorber, protecting items exposed to atmospheric agents and light for decades. In the case of light-colored vulcanized items, it is advisable to attenuate the phenomenon with: 1. high molecular weight Dutral

Maximum weather resistance can be obtained by using one or more of the following compounding techniques: 1. Adding pigments or fillers that give protection against UV light. 2. Using process oils that have a low aromaticity. 3. Adding zinc oxide beyond the recommended limit for curing. 4. Incorporating an antioxidant.

2. high purity paraffinic oils 3. zinc oxide, 15–20 phr 4. rutile titanium dioxide 5. phthalocyanine-based pigments The various UV stabilizers currently used with plastomeric polymers are not particularly effective.[206]

Outdoor Weather Resistance DuPont Nordel: Nordel hydrocarbon rubber can be compounded to give economical, highly weather resistant vulcanizates. After twenty years of continuous outdoor exposure in Florida (45◦ south), properly compounded mineral-filled vulcanizates show slight checking and moderate chalking with an erosion rate of about 0.5 mil/year. After twenty years in Florida (45◦ south), general purpose black-loaded compounds retain good elastomeric properties, show some chalking but with erosion rates of less than 0.05 mil/year. Slight surface checking is visible at 10× magnification.

Special Compounding when the Vulcanizate is Weathered with a Static or Dynamic Strain: General-purpose black vulcanizates from ethylenepropylene diene methylene (EPDM), while exhibiting outstanding weather resistance under normal exposure conditions, may show accelerated development of surface crazing if they are exposed while subject to a continuous static or dynamic strain. Surface crazing of Nordel hydrocarbon rubber vulcanizates, under these conditions, can be minimized by: •

Using a fine particle size black (e.g., HAF black).

•

Using a process oil with a low level of aromaticity (preferably less than 1% aromatics).

•

Using ca. 1 phr of an antioxidant. Neozone D is best, but a hindered bis-phenol antioxidant should be used if staining is a problem.

Special Compounding for Tensile Strength Retention: Mineral-filled vulcanizates from Nordel hydrocarbon rubber, like those from most other elastomers, tend to lose tensile strength when exposed to

346

The Effects of UV Light and Weather on Plastics and Elastomers

natural weathering. This loss can either be markedly reduced by compounding with 5 phr of Hypalon 45 synthetic rubber or completely eliminated by heat treating the stock with quinone dioxime. Quinone dioxime causes marked discoloration during cure, which limits its use to dark-colored vulcanizates.[207] Exxon Vistalon 5600 (features: black color, 76 Shore A hardness; material composition: 100 phr Vistalon 5600, 100 phr N-550 carbon black, 100 phr N-774 black, 100 phr naphthenic process oil, 5 phr zinc oxide, 2 phr stearic acid, 1 phr Flectol H (Monsanto), 2 phr sulfur, 1.5 phr Thiotax (Monsanto), 0.8 phr TDEDC, 0.8 phr DPTTS, 0.8 phr Thiurad (Monsanto)): EPDM was exposed to conventional Arizona aging by DSET Laboratories, Inc. (Phoenix, AZ) at a 5◦ tilt from the horizontal. This tilt is preferable to 0◦ as it allows for some drainage and dirt wash off during rains. Direct exposures are intended for materials that are to be used outdoors and subjected to all elements of weather. The exposure periods were 6, 12, 24, and 48 months. EPDM shows a color change (E) of less than 3 during the total aging cycle. Over the 48-month period EPDM experienced a significant increase in hardness and maintained reasonably good tensile strength. Although EPDM retained its tensile strength, its ability to be elongated decreased with exposure time. EPDM was also exposed to conventional Arizona aging with spray. This exposure method is the same as conventional aging, except that a water spray is used to induce moisture weathering conditions. The introduction of moisture plays an important role in improving both the relevancy and the reproducibility of the weathering test results. Spray nozzles are mounted above the face of the rack at points that are distributed so as to ensure uniform wetting of the entire exposure area. Distilled water is sprayed for four hours preceding sunrise to soak the samples, and then twenty times during the day in 15-second bursts. The purpose of the wetting is twofold. First, the introduction of water in the otherwise arid climate induces and accelerates some degradation modes that do not occur as rapidly, if at all, without moisture. Second, a thermal shock causes a reduction in

specimen surface temperatures as much as 14◦ C (25◦ F). This results in physical stresses that accelerate the degradation process. EPDM discolored within six months and continued to increase in E with exposure. The hardness of EPDM increases significantly with exposure time. Although EPDM maintained its tensile strength during the exposure period, its elongation decreased significantly with exposure. EPDM was also exposed to conventional Florida aging. This test method is a real-time exposure by DSET Laboratories, Inc. (Homestead, FL) at a 5◦ tilt from the horizontal. Since this location has a much higher average humidity, this exposure is harsher on some materials. Testing on EPDM was not accomplished over the total exposure period. Samples at 48 months had deteriorated past the point of meaningful testing. The data show significant color change with exposure time. The material sustained its tensile strength with exposure. Conventional Florida aging with spray was used to test EPDM. This exposure method is the same as conventional aging, except that a water spray is used to induce moisture weathering conditions. Moisture is introduced in the same manner as in Arizona. EPDM showed significant color and hardness changes during the 48 months of exposure, but retained good tensile strength. The specimens had a continuing decrease in elongation with exposure time.[208] EPDM (features: weatherable, black color, 65 Shore A hardness, 3.2 mm thick; manufacturing method: compression molding): EPDM rubber does not weather well when exposed under glass. The surface was covered with mildew like growth. Unsightly blemishes remained visible even after washing.[194]

Accelerated Outdoor Weathering Resistance Exxon Vistalon 5600: Outdoor accelerated exposure testing was done using equatorial mount with mirrors for acceleration (EMMA) on EPDM. This test method uses natural sunlight and special reflecting mirrors to concentrate the sunlight to the intensity

72: Ethylene-Propylene Diene Methylene Terpolymer

of about eight suns. A blower directs air over and under the samples to cool the specimens. This limits the increase in surface temperatures of most materials to 10◦ C (18◦ F) above the maximum surface temperature that is reached by identically mounted samples exposed to direct sunlight at the same time and locations without concentration. DSET Laboratories designed and maintains this equipment. The exposure period was a total of 6 and 12 months, which has been correlated to about 2.5 and 5 years of actual aging in a Florida environment, respectively. While EPDM retained its tensile strength, it showed a significant increase in hardness and a significant deterioration in elongation during the exposure period. Specimens were also exposed to an equatorial mount with mirrors for acceleration plus water (EMMAQUA). This is an accelerated weathering test method which uses the same apparatus as EMMA, except that a water spray is used to induce moisture weathering conditions. EPDM showed a major change in color and hardness along with significant decreases in elongation and tensile strength with exposure time.[208]

Accelerated Artificial Weathering Resistance Exxon Vistalon 5600: Under xenon arc weatherometer testing (as per General Motors standard TM302 and SAE J1885) EPDM displays a significant change in both color and hardness with exposure. Retention of tensile strength is good. However, elongation retention is poor.[208]

Effect of Carbon Black on Weatherability DuPont Nordel 1070 (cure: 20 minutes @ 160◦ C; features: black color; material composition: 100 phr Nordel 1070, 1 phr stearic acid, 5 phr zinc oxide, 80 phr paraffinic oil, 1.5 phr zinc dimethyl dithiocarbonate, 1.5 phr tetramethyl thiuram disulfide, 1 phr zinc mercatobenzothiazole, 2 phr sulfur, 80 phr

347

FEF carbon black), Nordel: Vulcanizates of Nordel hydrocarbon rubber have outstanding weather resistance when they contain at least 5 phr of a furnace black. In practical black-loaded vulcanizates, the concentrations of black and oil have no significant bearing on weather resistance within the ranges of 20–150 parts of black and 20–100 parts of oil. For example, weathering produces no more change in a vulcanizate loaded with 150 phr of black and 100 phr of oil than in one containing only 20 phr of each. Low concentrations (e.g., 5 phr) of furnace black provide very good weather protection in mineral-filled vulcanizates; compounds of this type are of particular interest in coverings for wires and cables.[207]

Effect of Color Pigments on Weatherability DuPont Nordel 1070 (cure: 20 minutes @ 160◦ C; features: white color; material composition: 100 phr Nordel 1070, 1 phr stearic acid, 20 phr zinc oxide, 80 phr hard clay, 80 phr paraffinic oil, 1.5 phr zinc dimethyl dithiocarbonate, 1.5 phr tetramethyl thiuram disulfide, 1 phr zinc mercaptobenzothiazole, 2 phr sulfur, 1 phr phenolic antioxidant, 35 phr Ti-Pure R-610 (replaced by Ti-Pure R-960), Nordel: All nonblack vulcanizates should contain titanium dioxide and/or opaque colored pigments since conventional mineral fillers, by themselves, provide little protection against UV radiation. Combinations of titanium dioxide and colored pigments can be used to produce weather resistant vulcanizates with bright colors or pastel shades. The table that follows lists proportions of individual pigments and pigment blends that provide optimum protection for mineral-filled vulcanizates of Nordel hydrocarbon rubber. Mineral-filled vulcanizates show better weather resistance at low to medium oil and filler loadings than at high extensions. Highly loaded vulcanizates (e.g., those containing 60 volumes of Nordel) tend to develop a brittle surface layer on weathering, causing fine cracks to appear on the surface if the vulcanizate is stretched or bent. This is not apparent when moderate loading levels are used, such as 30 volumes of filler per hundred volumes of Nordel.[207]

348

The Effects of UV Light and Weather on Plastics and Elastomers

Effective UV Screening Agents in Mineral-Filled Vulcanizates

Pigment

Suggested Combination of Pigment and Titanium Dioxide for Bright Color and Good Weathering (phr)

Minimum Amount of Pigment Alone, Needed for Good UV Screening (phr)

Pigment

Titanium Dioxide

2

20

Furnace Black

5

Ti-Pure R-960 (DuPont)

25

Phthalocyanine Green

5*

Chrome Green

9

Phthalocyanine Blue

8*

1

25

Chrome Yellow

9

5 to 10

20

Iron Oxide (Yellow or Red)

10

Quinacridone Red

8*

Pyrazalone Red

8

20 2

Note: Chrome yellow fades with clay loading. Super-Multiflex loading gives better color stability. With Super-Multiflex loading, 5 phr Hypalon 45 in the compound enhances physical properties. Pyrazalone Red gives a bright red color, but this fades with a clay loading. Super-Multiflex gives better color stability. This pigment can stain painted surfaces by migration from the vulcanizate. *Amount shown gives very dark colors.

Effect of Curing Systems on Weatherability DuPont Nordel: Good weather resistance can be obtained with sulfur or peroxide cures.[207]

Effect of Plasticizers on Weatherability DuPont Nordel 1070, Nordel: Vulcanizates of Nordel containing at least 20 phr of a reinforcing carbon black are so weather resistant that in most applications the type of oil used is unimportant. Differences between oils do become significant, however, with very long (e.g., 20 years) outdoor exposure, or if outdoor exposure involves flexing or static strain of 20% or more; in such cases,

naphthenic or paraffinic oils having a minimum aromatic content should be used, and 5% aromatic carbon atoms should be considered a maximum for these exposure conditions. Process oils with a minimum aromatic content should be used in all mineral-filled compounds for best weather resistance as well as good color stability during cure and weathering. If good color stability is essential, the oil—whether paraffinic or naphthenic—should be selected on the basis of minimum aromatic content.[207]

Ozone Resistance Exxon Vistalon 5600: The results of both ASTM D1171 and ASTM D518 ozone testing indicate that EPDM rubber exhibits outstanding resistance to ozone.[176]

72: Ethylene-Propylene Diene Methylene Terpolymer

349

Table 72-1. Mechanical Properties Retained after Outdoor and Accelerated Outdoor Weathering of White, Randomly Selected, Unstrained EPDM Terpolymer

350

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-2. Mechanical Properties Retained after Outdoor and Accelerated OutdoorWeathering of Black, Weather Resistant, Unstrained EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

351

Table 72-3. Mechanical Properties Retained after Outdoor and Accelerated OutdoorWeathering of Black, Randomly Selected, Unstrained EPDM Terpolymer

352

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-4. Mechanical Properties Retained and Color Change after Outdoor Weathering, Accelerated Outdoor Weathering by EMMAQUA, and Accelerated Weathering with a Xenon Arc Weatherometer for Black Exxon Vistalon EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

353

Table 72-5. Material Properties Retained and Color Change after Arizona Outdoor Weathering With and Without Water Spray Added for Black Exxon Vistalon 5600 EPDM Terpolymer

354

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-6. Mechanical Properties Retained and Color Change after Arizona Outdoor Weathering of Black Exxon Vistalon 5600 EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

355

Table 72-7. Mechanical Properties Retained after Florida Outdoor Weathering and Accelerated Outdoor Weathering by EMMA for Black, Weather Resistant, Strained EPDM Terpolymer

356

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-8. Material Properties Retained and Color Change after Florida Outdoor Weathering With and Without Water Spray Added for Black Exxon Vistalon 5600 EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

357

Table 72-9. Material Properties Retained and Surface and Appearance after Florida Outdoor Weathering of Weatherable EPDM Terpolymer

358

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-10. Mechanical Properties Retained after Florida Outdoor Weathering and Accelerated Outdoor Weathering by EMMA for Black, Randomly Selected, Strained EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

359

Table 72-11. Mechanical Properties Retained after Florida Outdoor Weathering and Accelerated Outdoor Weathering by EMMA for White, Randomly Selected, Strained EPDM Terpolymer

360

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-12. Material Properties Retained and Color Change after Florida Outdoor Weathering of Black EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

361

Table 72-13. Material Properties Retained and Color Change after Accelerated Outdoor Weathering by EMMA and EMMAQUA and Accelerated Weathering in a Xenon Arc Weatherometer for Black Exxon Vistalon 5600 EPDM Terpolymer

362

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-14. Mechanical Properties Retained and Color Change after Arizona Accelerated Outdoor Weathering by EMMA and EMMAQUA for Black Exxon Vistalon 5600 EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

363

Table 72-15. Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for White, Randomly Selected, Strained EPDM Terpolymer

364

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-16. Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for White, Randomly Selected, Unstrained EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

365

Table 72-17. Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for Black, Weather Resistant, Strained EPDM Terpolymer

366

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-18. Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for Black, Randomly Selected, Unstrained EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

367

Table 72-19. Mechanical Properties Retained and Color Change after Accelerated Weathering in a Xenon Arc Weatherometer of Black Exxon Vistalon 5600 EPDM Terpolymer

368

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-20. Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer for Black, Weather Resistant, Unstrained EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

369

Table 72-21. Mechanical Properties Retained after Accelerated Weathering in a UV-CON and a Xenon Arc Weatherometer of Black, Randomly Selected, Strained EPDM Terpolymer

370

The Effects of UV Light and Weather on Plastics and Elastomers

Table 72-22. Surface and Appearance and Ozone Resistance of Exxon Vistalon EPDM Terpolymer

72: Ethylene-Propylene Diene Methylene Terpolymer

Table 72-23. Surface and Appearance and Ozone Resistance of EPDM Terpolymer

371

372

The Effects of UV Light and Weather on Plastics and Elastomers

Graph 72-1. Carbonyl Formation after Xenon Arc Weatherometer Exposure of EPDM Terpolymer.

Graph 72-2. Decrease in Molecular Weight after Xenon Arc Weatherometer Exposure of EPDM Terpolymer.

Chapter 73

Neoprene Rubber Category: Elastomer, thermoset. General Properties: DuPont Elastomers Neoprene® is composed of polychloroprene. The polymer structure can be modified by copolymerization with sulfur or 2,3-dichloro-1,3-butadiene to yield a broad range of chemical and physical properties.

Weathering Properties All types of neoprene resist degradation from the sun, ozone, and weather, and perform well in contact with oils and many chemicals. Chloroprene (black color, 76 Shore A hardness) with the following composition—100 phr Neoprene W, 1 phr stearic acid, 4 phr magnesium oxide, 2 phr Flectol ODP, 70 phr N-774 black, 25 phr N-330 black, 25 phr process oil, 5 phr zinc oxide, 1 phr sulfur, 0.75 phr monothruad, 0.75 phr DOTG— was exposed to the following weathering tests. Arizona Aging: Samples were exposed at a 5◦ tilt from the horizontal. This tilt is preferable to the flat or 5◦ position since it allows for some drainage and dirt to wash off during rains. Direct exposures are intended for materials that will be used outdoors and subjected to all elements of weather. The exposure periods were 6, 12, 24, and 48 months. Chloroprene showed a color change (E) of less than 3 during the total aging cycle. Over the 48-month period chloroprene experienced a significant increase in hardness and maintained reasonably good tensile strength. Although chloroprene retained its tensile strength, its ability to be elongated decreased with exposure.[208] Arizona Aging with Spray: The introduction of moisture plays an important role in improving both the relevance and the reproducibility of the weathering test results. The introduction of water in the otherwise arid climate induces and accelerates some

degradation modes that do not occur as rapidly, if at all, without moisture. In addition, a thermal shock causes a reduction in specimen surface temperatures as much as 14◦ C (61◦ F). This results in physical stresses that accelerate the degradation process. Chloroprene discolored within six months and continued to increase in E with exposure. The hardness of chloroprene increased significantly while the elongation decreased significantly with exposure time. During the exposure period the material maintained its tensile strength.[208] Florida Aging: This test method is a real-time exposure at a 5◦ tilt from the horizontal. Since this location has a much higher average humidity, this exposure is harsher on some materials. Samples at 48 months had deteriorated past the point of meaningful testing. The data show significant color change with exposure time. Chloroprene showed a major decrease in both tensile strength and elongation retention almost immediately after exposure.[208] Florida Aging with Spray: This outdoor exposure method is the same as the conventional aging, except that a water spray is used. Chloroprene showed significant color, hardness, and tensile strength changes during the 48 months of exposure. The specimens also had a continuous decrease in elongation with exposure time.[208] EMMA: The exposure period was a total of 6 and 12 months, which has been correlated to about 2.5 and 5 years of actual aging in a Florida environment, respectively. While chloroprene retained its tensile strength, it showed a significant increase in hardness and a significant deterioration in elongation during the exposure period.[208] EMMAQUA: This method uses the EMMA set-up with a water spray to induce moisture weathering conditions. Chloroprene specimens at 24 months had deteriorated past the ability to obtain reasonable data.

374

The Effects of UV Light and Weather on Plastics and Elastomers

Prior to that point there were large color changes, significant loss in tensile strength, and a major decrease in elongation with exposure time.[208] Xenon Arc: Chloroprene displays a significant change in both color and hardness with exposure.

Retention of tensile strength is good, however, retention of color is poor.[208] Ozone: Under test method ASTM D1171, neoprene cracked within eight hours. Using ASTM D518, neoprene rubber cracked within three hours.[208]

Weathering Properties by Material Supplier Trade Name Table 73-1. Mechanical Properties Retained and Color Change after Arizona Outdoor Weathering and Accelerated Outdoor Weathering by EMMAQUA and Xenon Arc Accelerated Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber

73: Neoprene Rubber

375

Table 73-2. Material Properties Retained, Hardness Change, and Color Change after Arizona and Florida Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber

376

The Effects of UV Light and Weather on Plastics and Elastomers

Table 73-3. Mechanical Properties Retained and Color Change after Arizona Outdoor Weathering and Arizona Outdoor Weathering with Spray for Black DuPont Neoprene® W Neoprene Rubber

73: Neoprene Rubber

377

Table 73-4. Material Properties Retained, Hardness Change, and Color Change after Arizona Outdoor Weathering and Arizona Outdoor Weathering with Spray for Black DuPont Neoprene® W Neoprene Rubber

378

The Effects of UV Light and Weather on Plastics and Elastomers

Table 73-5. Material Properties Retained, Hardness Change, and Color Change after Florida Outdoor Weathering and Florida Outdoor Weathering with Spray for Black DuPont Neoprene® W Neoprene Rubber

73: Neoprene Rubber

379

Table 73-6. Material Properties Retained, Hardness Change, and Color Change after Xenon Arc Accelerated Weathering and EMMA and EMMAQUA Accelerated Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber

380

The Effects of UV Light and Weather on Plastics and Elastomers

Table 73-7. Mechanical Properties Retained and Color Change after EMMA and EMMAQUA Arizona Accelerated Outdoor Weathering for Black DuPont Neoprene® W Neoprene Rubber

73: Neoprene Rubber

381

Table 73-8. Mechanical Properties Retained and Color Change after Xenon Arc Accelerated Weathering for Black DuPont Neoprene® W Neoprene Rubber

382

The Effects of UV Light and Weather on Plastics and Elastomers

Table 73-9. Ozone Resistance after Exposure of Black DuPont Neoprene® W Neoprene Rubber

Chapter 74

Polybutadiene Category: Elastomer, thermoset.

Weathering Properties

General Properties: Japanese Synthetic Rubber offers JSR BR, a low molecular weight, low crystallinity syndiotactic 1,2-polybutadiene that has a crystallinity of 15–30%.

Polybutadiene, a main component of acrylonitrile-butadiene-styrene, is susceptible to light-induced degradation.

384

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 74-1. Ozone Resistance of Japanese Synthetic Rubber JSR BR Polybutadiene Rubber

Chapter 75

Polyisoprene Rubber Category: Elastomer, thermoset. General Properties: Polyisoprene rubber is chemically similar to natural rubber. Goodyear Natsyn® is a synthetic cis-polyisoprene.

Weathering Properties Polyisoprene is susceptible to degradation by weathering. Like most polymers, Goodyear Natsyn® does not resist degradation due to exposure to UV radiation and ozone unless special compounding techniques are employed. In a recipe similar to a truck tire tread compound, two antiozonants are compared alone and in combination with Sunlite® 240 wax. Agerite® Resin D at 10 phr is included because it is one way to provide ozone protection and avoid the staining characteristics of most antiozonants.[211] In general, the alkyl-aryl p-phenylenediamines give the best ozone resistance to Natsyn® and natural compounds. Dialkly p-phenylenediamines are also effective but less persistent. When a dialkyl pphenylenediamine is used, a secondary antiozonant will extend the longevity of protection.[211] It is often advantageous to use special waxes in combination with the antiozonant. Wax is especially

suitable for static applications because it blooms to the surface of the compound and becomes a protective coating. However, wax has a significant adverse effect on ozone resistance in dynamic applications and so a good antiozonant is required for maximum protection.[211] Polymer blending is another way of improving the aging resistance of Natsyn® . Ethylene-propylene terpolymers (EPDM) are inherently immune to attack by ozone and oxygen and, when properly blended, are capable of extending this protection to Natsyn® . In addition, EPDM polymers neither stain nor disappear through volitization. These blends are thus suitable for use in light-colored stocks.[211] In order to achieve the maximum benefit from EPDM, proper mixing is essential. Natsyn® breaks down rapidly in a mill, but EPDM polymers do not. A better dispersion of the two polymers will result if they have close Mooney viscosities. Experience has shown that ozone resistance is greatly enhanced if the polymers are well blended before other compounding materials are added. Care should be taken to keep the mixing temperature below 149◦ C in the Banbury to prevent degradation of Natsyn® . Otherwise normal mixing procedures are satisfactory.[211]

386

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 75-1. Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per the Annulus Test

75: Polyisoprene Rubber

387

Table 75-2. Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per ASTM D1171 Loop Ozone Test

388

The Effects of UV Light and Weather on Plastics and Elastomers

Table 75-3. Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per the Static Strip Test

75: Polyisoprene Rubber

389

Table 75-4. Ozone Resistance of Goodyear Natsyn® 2200 Polyisoprene Rubber as per the Kinetic Stretch Test

Chapter 76

Polyurethane Category: Polyurethane. General Properties: United Coatings Elastuff 101/102 is a high solids, moisture-catalyzed, singlecomponent polyurethane coating system. The system consists of Elastuff 101, an aromatic polyurethane basecoat, and Elastuff 102, a UV-resistant, 100% aliphatic polyurethane topcoat.[212]

Weathering Properties The Elastuff 101/102 system is designed for protecting a wide range of substrates from the effects of weathering and moisture intrusion. It is particularly effective as a protective membrane over polyurethane foam on new or existing roofs, and hot or ambient storage tanks. It provides a barrier to the effects of degradation caused by normal weathering, aging, and UV exposure.[212] Test panels were placed in the QUV Accelerated Weathering Tester. The cycle consisted of four hours of UV radiation (during which time temperatures reached approximately 35◦ F (1.5◦ C)) and four hours with no UV radiation. A water bath at the bottom of the unit is maintained at 100◦ F (38◦ C) to create a constant high humidity condition.

After 3000 hours of continuous testing, the Elastuff 101/102 system showed no surface checking or cracking, no delamination or loss of flexibility, and no chalking.[212]

Weathering Properties: Stabilization The weathering of polyurethanes based on metatetramethylxylene diisocyanate TMXDI (META) aliphatic isocyanate is similar to that of other aliphatic isocyanates in that surface quality and gloss retention are excellent. Both TMXDI (META) and an H12 MDI system for urethane roof topcoats were exposed in a xenon arc weatherometer. QUV values were found to be similar to the xenon data reported. The weatherability of TMXDI (META) aliphatic isocyanate exceeds that observed for the H12 MDI system.[213] Although the molecule of TMXDI (META) aliphatic isocyanate is built around an aromatic ring, the isocyanate functionalities are not conjugated and are aliphatic. Thus, the quinoid structures that give rise to the poor weatherability of true aromatics, such as toluene diisocyanate, are not possible. In addition, the presence of methyl groups in the place of benzylic hydrogens further enhances the UV stability.[213]

392

The Effects of UV Light and Weather on Plastics and Elastomers

Weathering Properties by Material Supplier Trade Name Table 76-1. Gloss Retained after Xenon Arc Accelerated Weatherometer Exposure of Polyurethane Rubber

Graph 76-1. Change in Color, b, after Florida Outdoor Weathering of Polyurethane.

Chapter 77

Silicone Rubber Category: Silicone, thermoset. General Properties: Silicone rubber is a unique synthetic elastomer made from a cross-linkable polymer which is reinforced with silica. Dow Corning Silastic® is a ready-to-use blend of a silicone rubber base, fillers, modifiers, vulcanizing agents, and pigments.[214]

Weathering Properties The weathering characteristics of Dow Corning Silastic® silicone rubber were tested at two sites: Southern Florida and Central Michigan (USA). All test specimens were prepared and mounted in accordance with ASTM D518, Method A, and were in a stressed condition, faced southward, and tilted

upward to catch the full impact of the elements. Because no cracking or checking developed in any Silastic® silicone rubber, an additional evaluation procedure was used—ASTM D518, Method B. Periodically, some samples were removed, cut into standard tensile bars, and tested for tensile strength, durometer hardness, and ultimate elongation. For most elastomers, this added test is too severe, because even the smallest crack will start a tear and yield very low tensile strength. In general, Test Method B provides a more stringent weathering test than Test Method A.[214] A visual inspection of the weathered Silastic® silicone rubber samples from the Florida test station showed minor surface checking after 234 months (equivalent to 27,799 sun hours).[214] Note: Samples were conditioned using MethodA and Method B of ASTM D518.

Weathering Properties by Material Supplier Trade Name Table 77-1. Change in Mechanical Properties after Florida and Michigan Outdoor Weathering for Dow Corning Silastic® Silicone Rubber as per ASTM D518, Method A Material Family

Silicone Rubber Corning Silastic® Silicone Rubber

Material Supplier Reference Number

214

Exposure Conditions Exposure Location

ASTM D518, Method A Michigan

Michigan

Michigan

Florida

1 year

2 years

5 years

20 years

Tensile Strength (%)

+8 to −25

+4 to −22

+22 to −27

−31

Elongation (%)

+4 to −28

+14 to −34

−55

Hardness (Point Change)

+3 to −6

+2 to −6

+8 to −9

Exposure Time PROPERTY CHANGE

+7

394

The Effects of UV Light and Weather on Plastics and Elastomers

Table 77-2. Change in Mechanical Properties after Florida and Michigan Outdoor Weathering for Dow Corning Silastic® Silicone Rubber as per ASTM D518, Method B Material Family

Silicone Rubber Corning Silastic® Silicone Rubber

Material Supplier Reference Number

214

Exposure Conditions Exposure Location

ASTM D518, Method B Michigan

Michigan

Michigan

Florida

1 year

2 years

5 years

20 years

0 to −23

−8 to −42

−14 to −54

−41

Elongation (%)

+4 to −40

0 to −45

−24 to −50

−60

Hardness (Point Change)

+1 to −8

−3 to −16

+5 to −8

+2

Exposure Time PROPERTY CHANGE Tensile Strength (%)

Appendix 1

Fluoropolymers in Coating Applications Architectural Fabrics Architectural fabrics are engineered materials that are available to architects and engineers for the design and construction of textile structures. They are flexible and strong and offer the designer many options with respect to strength, aesthetic requirements, fire codes, weatherability, expected lifetime, and more. Most tensile structures utilize fabrics rather than meshes or films. Two basic families of fabrics are available—woven fabrics that consist of two sets of yarns (warp and weft) woven together in a loom and foils that are made of thinly rolled or extruded homogenous material. Coatings and top finishes are applied to provide aesthetics as well as to protect the materials from UV radiation, moisture, dirt and/or chemicals. Coatings can also add strength to a fabric. The most widely used materials are woven polyester cloths coated with polyvinyl chloride (PVC) and woven fiberglass coated with either polytetrafluoroethylene (PTFE) or silicone.

Fabric Base Materials •

PTFE is a high strength, waterproof material completely immune to UV radiation. DuPont Teflon® is a PTFE.

•

Kevlar® is extremely strong (three times the strength of steel on an equal weight basis) with good abrasion resistance and little chemical and thermal degradation. However, it is subject to UV deterioration. Kevlar® coated with PVC has found a few high-strength architectural applications.

•

Polyethylene can be made into an architectural fabric with impressive tensile and tear strength and a life span equal to PVC. Polyethylene fabrics are unique

in that both the fabric and the coating are made of polyethylene. •

Polyester base cloth is used because of its durability, strength, and relatively low cost. It is woven or knitted to highly controlled specifications to give the fabric strength, visual consistency, and measurable properties of stretch and strength.

•

Woven glass fiber, often called fiberglass, is commonly used as a base fabric for silicone and PTFE-coated applications. The coated glass fabric is inert, ages well, and does not emit toxic gases.

Fabric Coatings •

PVC is the most commonly used coating for architectural purposes. PVC can be made flexible and flame retardant by adding chemical compounds. Through the addition of a topcoat, the outdoor life of PVC can be increased and its tendency to attract dirt can be reduced.

Fabric Top Finishes or Topcoats Most architectural materials have some sort of top finishes applied to their exterior or weathering surface. Top finishes to architectural fabrics provide protection from UV degradation, water and wind damage, repel dirt, and can provide a pleasing aesthetic component to the material. If the top finish deteriorates and exposes the PVC beneath it, the PVC will begin to lose its aesthetic benefit. The application of a proper top finish improves the appearance of the materials, and produces a material that will resist

396

The Effects of UV Light and Weather on Plastics and Elastomers

environmental elements and retain a bright, clean appearance over the expected life of the structure. Typical PVC topcoats are acrylic lacquers, polyvinylidene fluoride (PVDF) coatings, and polyvinyl fluoride (PVF) laminates. •

•

•

Acrylic is the most economical and most widely available finish. It is applied as a thin spray-applied solution that gives a transparent glossy finish to the PVC. Acrylics generally have fair to good resistance to UV degradation. Acrylic topcoats are ideal for fabrics that are used for temporary structures and demountable structures such as marquees, circus tents, and warehouses. PVDF is made up of 59% fluorine, 38% carbon, and 3% hydrogen and is bonded to the PVC. PVDF offers resistance to UV degradation and atmospheric chemical attack, which is far superior to the acrylic topcoat. Controlled exposure tests in Florida indicate that change in color and gloss are significantly less, over time, than its acrylic counterpart. PVDF topcoats also offer resistance to algae and fungal attack. They have good self-cleaning properties and therefore need little maintenance. These properties combine to give the membrane a life span of 15–20 years depending on site conditions. PVDF is usually compounded with acrylics for outdoor coating applications to reduce cost and make it heat sealable. PVF belongs to the same polymer family as Teflon® , and the DuPont trade name is Tedlar® . PVF is bonded to the vinyl fabric in film form in a laminating process and results in a thicker finished fabric that is resistant to degradation from UV radiation, is durable, and maintains its essentially “self-cleaning” attributes resisting

attack from graffiti, acid rain, and bird droppings. Having a thicker coating, it erodes at a much slower rate giving it a life expectancy of about 25 years depending on conditions. The Tedlar® film topcoating not only resists environmental degradation but also eliminates the migration of plasticizers from the base PVC coating. Tedlar® does not contain a plasticizer. The Tedlar® topcoating is flexible, allowing a consistent and strong bond to the PVC. PVF is frequently specified for use in highly industrialized areas, high saline coastal zones, and desert environments. •

PVDF/PVC topcoating is effectively a dilution of the PVDF topcoat. This gives the finished fabric the advantages of being less expensive to produce and to fabricate. The diluted effect of the PVDF, however, means that environmental resistance is reduced along with longevity. Fabrics with this coating have a life expectancy of 10–15 years, depending on prevailing conditions.

Weathering Resistance Seven different commercially available materials were evaluated by DuPont. All were white and were promoted by their manufacturers as architectural fabrics for commercial use today. All seven samples were subjected to accelerated weathering and were monitored at selected intervals. The thickness of the protective layer was measured by optical microscopy or by transmission electron microscopy (TEM). Color and 60◦ gloss change were recorded as well.[215] After 2.5 years of natural weathering, the acrylic and PVDF coatings show significant dirt accumulation and discoloration, while the fabric bonded with Tedlar® PVF shows no signs of discoloration or significant dirt accumulation.[215]

397

Appendix 1: Fluoropolymers in Coating Applications

Graph A1-1. Top Finish Thickness after Accelerated Florida Outdoor Exposure Testing for Acrylic, PVDF, and DuPont Tedlar® PVF Top Finishes.[215] 1.0

Tedlar ® PVF Film

Protection thickness (mil)

0.9

Acrylic “A” Topcoat

0.8

Acrylic “B” Topcoat

0.7

Acrylic “C” Topcoat

0.6

PVDF “A” Topcoat PVDF “B” Topcoat

0.5

PVDF “C” Topcoat

0.4 0.3 0.2 0.1 0.0

0.0

1.3

2.7

4.0

5.3

6.7

8.0

9.3

Years of Simulated Florida Outdoor Exposure

Graph A1-2. Color Change, E, after Accelerated Florida Outdoor Exposure Testing for Acrylic, PVDF, and DuPont Tedlar® PVF Top Finishes.[215] 12

Tedlar ® PVF Film Acrylic “A” Topcoat Acrylic “B” Topcoat Acrylic “C” Topcoat PVDF “A” Topcoat PVDF “B” Topcoat PVDF “C” Topcoat

Color Change (∆E)

10 8 6 4 2 0

0.0

1.3

2.7

4.0

5.3

6.7

Years of Simulated Florida Outdoor Exposure

8.0

9.3

398

The Effects of UV Light and Weather on Plastics and Elastomers

Graph A1-3. Gloss Change, 60◦ Gloss, after Accelerated Florida Outdoor Exposure Testing for Acrylic, PVDF, and DuPont Tedlar® PVF Top Finishes.[215] 70

Tedlar ® PVF Film Acrylic “A” Topcoat Acrylic “B” Topcoat Acrylic “C” Topcoat PVDF “A” Topcoat PVDF “B” Topcoat PVDF “C” Topcoat

60

60° Gloss

50 40 30 20 10 0

0.0

1.3

2.7

4.0

5.3

6.7

8.0

9.3

Years of Simulated Florida Outdoor Exposure Note: Exposures of 1200 kJ are equivalent to one year of South Florida exposure at an angle of 45◦ from the horizontal.

Appendix 2

Coil Coatings Comparative Properties and Performance Chart Coil Coating Topcoats The Comparative Properties and Performance Chart has been created to provide a description of the physical and performance properties of various coil coating topcoats. This chart has been prepared to

provide only general information. It is neither a performance standard nor a specification. It describes broad performance criteria and should never be used on its own to select a particular coating technology for a specific application. A wide range of performance criteria exist within any generic coating category. It is advisable to consult the coating suppliers regarding your specific needs.

Table A2-1. Comparative Properties and Performance Chart—Coil Coating Topcoats[216]

Weathering Properties

ASTM Method

Gloss Retention 5 Years Florida, 45◦ South

Polyester Interior Use Only/Exterior Use

Plastisol

Solution Acrylic

Silicone Polyester

Polyvinylidene Fluoride

Acrylic Latex

Polyurethane

G7, D1014, D523

2–3

3

N/A

3–4

4

5

3–4

3–4

Chalk 5 Years Florida, 45◦ South

G7, D1014, D4214

2–3

3

N/A

3–4

4

5

3–4

3–4

Color Retention 5 Years Florida, 45◦ South

G7, D1014, D2244

2–3

3

N/A

3–4

4

5

3–4

3–4

5, excellent; 4, very good; 3, good; 2, fair; 1, poor. This chart has been prepared by The National Coil Coaters Association Technology Committee.

Glossary of Terms A AATCC method 16: A method developed by the American Association of Textile Chemists and Colorists for the accelerated testing of the colorfastness of fabrics and yarns to light. Exposure conditions are: for option A—continuous borosilicate glass-filtered core/solid carbon-arc lamp irradiation, option C—continuous daylight carbon-arc lamp irradiation, option D—same as option A but alternating with dark periods, option E—continuous borosilicate/sodalime glass-filtered water-cooled xenon-arc lamp irradiation, option F—same as option E but alternating with dark periods, option I—continuous soda-lime glass-filtered air-cooled xenon-arc lamp irradiation, option J—same as option I but alternating with dark periods. The color change of white card-mounted specimens is evaluated by rating against AATCC gray scale, colorimetry in AATCC fading units, or determination of E value. The exposure stages are determined with simultaneously exposed AATCC Blue Wool Standards or reference specimens. Also called AATCC method 16C.

AATCC method 16C: See AATCC method 16.

AATCC method 111B: A method developed by the American Association of Textile Chemists and Colorists for the weather resistance testing of fabrics and yarns. The specimens, secured in special frames, are exposed to natural sunlight and weathered around the clock in uncovered cabinets with or without backing on racks facing the equator. The conditions of the test are recorded by measuring maximum and minimum temperatures and relative humidity values, hours of wetness for rain and rain plus dew, and total and UV radiant energy. The weatherability of the specimens is assessed by comparing with standard samples and by measuring the percentage residual strength (breaking, tearing, or burst) and/or colorfastness.

AATCC method 111D: A method developed by the American Association of Textile Chemists and Colorists for testing the resistance of fabrics and yarns to weather, excluding precipitation. The specimens, secured in special frames, are exposed to natural sunlight and weathered around the clock in glass-covered ventilated cabinets with backing on sloped racks. The glass is 2.0–2.5 mm thick, absorbing radiation less than 310 nm. The conditions of the test are recorded by measuring maximum and minimum temperatures and relative humidity values, and radiant energy. The weatherability of the specimens is assessed by comparing with standard samples and by measuring the percentage residual strength (breaking, tearing, or burst) and/or colorfastness. AATCC method 169: A method developed by the American Association of Textile Chemists and Colorists for the accelerated testing of the resistance of fabrics and yarns to weather in an artificial weathering apparatus. The specimens are exposed to water- or air-cooled long arc xenon lamp irradiation on variously positioned racks at different radiant energy levels. In the semitropical climate exposure (option 1), the specimens are irradiated for 90 minutes and water-sprayed for 30 minutes at 77◦ C and 70% relative humidity. In the arid climate exposure (option 3), the specimens are irradiated only. In the Columbus, Ohio, climate exposure (option 4), the specimens are irradiated at 102 minutes and water-sprayed for 18 minutes at 63◦ C and 50% relative humidity. The weatherability of the specimens is assessed by comparing with standard samples and by measuring the percentage residual strength (breaking, tearing, or burst) and/or colorfastness. ABS: See acrylonitrile-butadiene-styrene polymer. ABS nylon alloy: See acrylonitrile-butadienestyrene polymer nylon alloy. ABS PC alloy: See acrylonitrile-butadiene-styrene polymer polycarbonate alloy.

402

The Effects of UV Light and Weather on Plastics and Elastomers

ABS resin: See acrylonitrile-butadiene-styrene polymer.

Used in construction, leisure, and automotive applications such as siding, exterior auto trim, and outdoor furniture. Also called ASA.

accelerant: See accelerator. accelerated indoor colorfastness test: See accelerated indoor light colorfastness test. accelerated indoor light colorfastness test: An indoor test that measures the resistance of a colored plastic to fading and/or discoloration on prolonged exposure to a common source of UV radiation such as sunlight, glass-filtered daylight, or fluorescent lighting. The test is performed in controlled simulated environments using artificial light sources at high levels of radiance to reduce the test time. The sources used include xenon arc, carbon arc, and fluorescent lamps. Also called accelerated indoor colorfastness test. accelerator: A chemical substance that accelerates chemical, photochemical, biochemical, etc. reactions or processes, such as cross-linking or degradation of polymers, that is triggered and/or sustained by another substance, such as a curing agent or catalyst, or environmental factors, such as heat, radiation, or a microorganism. Also called accelerant, promoter, cocatalyst. acetal resins: Thermoplastics prepared by the polymerization of formaldehyde or its trioxane trimer. Acetals have high impact strength and stiffness, low friction coefficient and permeability, good dimensional stability and dielectric properties, and high fatigue strength and thermal stability. Acetals have poor acid and UV resistance and are flammable. Processed by injection and blow molding and extrusion. Used in mechanical parts such as gears and bearings, automotive components, appliances, and plumbing and electronic applications. Also called acetals.

acrylic resins: Thermoplastic polymers of alkyl acrylates such as methyl methacrylates. Acrylic resins have good optical clarity, weatherability, surface hardness, chemical resistance, rigidity, impact strength, and dimensional stability. They have poor solvent resistance, resistance to stress cracking, flexibility, and thermal stability. Processed by casting, extrusion, injection molding, and thermoforming. Used in transparent parts, auto trim, household items, light fixtures, and medical devices. Also called polyacrylates. acrylonitrile-butadiene-styrene polymer: ABS resins are thermoplastics comprising a mixture of styrene-acrylonitrile copolymer (SAN) and SANgrafted butadiene rubber. They have high impact resistance, toughness, rigidity, and processability, but low dielectric strength, continuous service temperature, and elongation. Outdoor use requires protective coatings in some cases. Plating grades provide excellent adhesion to metals. Processed by extrusion, blow molding, thermoforming, calendaring, and injection molding. Used in household appliances, tools, nonfood packaging, business machinery, interior automotive parts, extruded sheets, pipes and pipe fittings. Also called ABS, ABS resin. acrylonitrile-butadiene-styrene polymer nylon alloy: A thermoplastic processed by injection molding, with properties similar to ABS but higher elongation at yield. Also called ABS nylon alloy. acrylonitrile-butadiene-styrene polymer polycarbonate alloy: A thermoplastic processed by injection molding and extrusion, with properties similar to ABS. Used in automotive applications. Also called ABS-PC alloy.

acetals: See acetal resins. acrylate-styrene-acrylonitrile polymer: Acrylic rubber-modified thermoplastic with high weatherability. ASA has good heat and chemical resistance, toughness, rigidity, and antistatic properties. Processed by extrusion, thermoforming, and molding.

acrylonitrile copolymer: A thermoplastic prepared by copolymerization of acrylonitrile with small amounts of other unsaturated monomers. Has good gas barrier properties and chemical resistance. Processed by extrusion, injection molding, and thermoforming. Used in food packaging.

Glossary of Terms

alcohols: A class of hydroxy compounds in which a hydroxy group(s) is attached to a carbon chain or ring. Alcohols are produced synthetically from petroleum stock (e.g., by hydration of ethylene) or derived from natural products (e.g., by fermentation of grain). Alcohols are divided into the following groups: monohydric, dihydric, trihydric, and polyhydric. Used in organic synthesis as solvents, plasticizers, fuels, beverages, detergents, etc. amorphous nylon: Transparent aromatic polyamide thermoplastics. anatase TiO2 : See anatase titanium dioxide. anatase titanium dioxide: One of the naturally occurring crystal forms of titanium dioxide. Used as a white or opacifying pigment in a wide range of materials including coatings and plastics. Anatase titanium dioxide has a lower refractive index and opacity than rutile titanium dioxide, another crystal form of this oxide. The pigment is nonmigrating, heat resistant, chemically inert, and lightfast. Also called anatase TiO2 . annulus test: An ozone resistance test for rubbers that involves a flat-ring specimen mounted as a band over a rack, stretched 0–100% and subjected to ozone attack in the test chamber. The specimen is evaluated by comparing to a calibrated template to determine the minimum elongation at which cracking occurs. anthraquinone: An aromatic compound comprising two benzene rings linked by two carbonyl (C=O) groups, C6 H4 (CO)2 C6 H4 . Combustible. Used as an intermediate in organic synthesis, mainly in the manufacture of anthraquinone dyes and pigments. One method of preparation is by condensation of 1,4-naphthaquinone with butadiene. antioxidant: A chemical substance capable of inhibiting oxidation or oxidative degradation of another substance such as a plastic in which it is incorporated. Antioxidants act by terminating chainpropagating free radicals or by decomposing peroxides, formed during oxidation, into stable products. The first group of antioxidants include hindered phenols and amines, the second group include sulfur compounds such as thiols.

403 Arizona aging: An outdoor exposure test performed in Arizona, USA, under climatic conditions characterized by high annual solar radiation and temperature to evaluate the weatherability of materials such as coatings or plastics. Special panels with specimens are exposed at a standard tilt angle for 6–48 months. The aging of the specimens is assessed visually and by measuring the changes in color, surface, mechanical (e.g., hardness and tensile strength) and other properties. aromatic polyester estercarbonate: A thermoplastic block copolymer of an aromatic polyester with polycarbonate. Has higher heat distortion temperature than regular polycarbonate. aromatic polyesters: Engineering thermoplastics prepared by the polymerization of aromatic polyols with aromatic dicarboxylic anhydrides. They are tough with somewhat low chemical resistance. Processed by injection and blow molding, extrusion, and thermoforming. Drying is required. Used in automotive housings and trim, electrical wire jacketing, printed circuit boards, and appliance enclosures. artificial accelerated weathering: An indoor test in which a material, such as plastic, is exposed to simulated outdoor conditions (sunlight, temperature changes, humidity, marine environment) harsher than normal to produce changes or degradation faster. The test is performed in a controlled environment such as a climatic or weathering chamber with artificial light sources like xenon arc lamps. The weathering of the specimens is assessed visually and by measuring the changes in color, surface, mechanical (e.g., hardness and tensile strength) and other properties. ASA: See acrylate-styrene-acrylonitrile polymer. Aspergillus flavus: A species of common mold belonging to the genus Aspergillus. Used alone or in artificial mixtures with other fungi to prepare cultures for the testing of mildew resistance of materials such as plastics, or fungicidal activity of antimildew agents or fungicides. Aspergillus niger: A species of common mold belonging to the genus Aspergillus. Used alone or

404

The Effects of UV Light and Weather on Plastics and Elastomers

in artificial mixtures with other fungi to prepare cultures for the testing of mildew resistance of materials such as plastics, or fungicidal activity of antimildew agents or fungicides. Aspergillus versicolor: A species of common mold belonging to the genus Aspergillus. Used alone or in artificial mixtures with other fungi to prepare cultures for the testing of mildew resistance of materials such as plastics, or fungicidal activity of antimildew agents or fungicides. ASTM B117: An American Society for Testing of Materials standard method for salt spray (fog) testing of materials such as metallic and nonmetallic coatings on metal substrates. The specimens are exposed to a fine spray of a NaCl solution at about 35◦ C in a special chamber for an extended period of time. The results are assessed visually by checking for a specified extent of corrosion damage or by a measuring technique such as impedance. ASTM B368: An American Society for Testing of Materials standard method for copper-accelerated acetic acid-salt spray (fog) testing of copper-nickelchromium or nickel-chromium coatings on metal and plastic substrates. The method sets forth test conditions for evaluating anticorrosive properties of coatings exposed to a fine spray of a NaCl-CuCl2 AcOH solution (pH 3.1–3.3) at about 49◦ C in a special chamber for 6–720 hours. The results are assessed by measuring the rate of corrosion (i.e., weight loss per unit area of the test panel). ASTM C793: An American Society for Testing of Materials standard method for testing the effects of accelerated weathering on elastomeric joint sealants used in building construction. The sealants are spread on aluminum plates and exposed to 250 hours of UV radiation with intermittent water spray in a weathering chamber, followed by freezing at about −26◦ C for 24 hours with subsequent bending over a mandrel at a specified temperature, The results are evaluated by visual examination of the specimens for cracks. ASTM D256: An American Society for Testing of Materials standard method for determination of the resistance to breakage by flexural shock of plastics and electrical insulating materials, as indicated by the energy extracted from standard pendulum-type

hammers in breaking standard specimens with one pendulum swing. The hammers are mounted on standard machines of either Izod or Charpy type. Note: Impact properties determined include Izod or Charpy impact energy normalized per width of the specimen. Also called ASTM method D256-84. See also impact energy. ASTM D279: An American Society for Testing of Materials standard method for determining the bleeding (migration) characteristics of dry pigments by direct solvent extraction of the pigment, or by overstriping a film containing the pigment with a white coating and observing for the color migration from the base coat containing the pigment. During extraction, the pigment is shaken with toluene, filtered, and the filtrate is observed for color. The degree of bleeding is rated from none to severe. ASTM D395: An American Society for Testing of Material standard method for testing the capacity of rubber to recover from compressive stress in air or liquid media. The specimen is subjected to compression by a specified force for a definite time at a specified temperature. The difference between the original and the final specimen thickness or compression set is calculated as a percentage of the original thickness by measuring the final thickness 30 minutes after stress removal. ASTM D412: An American Society for Testing of Materials standard method for determining tensile strength, tensile stress, ultimate elongation, tensile set, and set after break of rubber at low, ambient, and elevated temperatures using straight, dumbbell, and cut-ring specimens. ASTM D471: An American Society for Testing of Materials standard method for determining the resistance of nonporous rubber to hydrocarbon oils, fuels, service fluids, and water. The specimens are immersed in fluids for 22–670 hours at −75 to 250◦ C, followed by measuring of the changes in mass, volume, tensile strength, elongation, and hardness for solid specimens, and the changes in breaking strength, burst strength, tear strength, and adhesion for rubber-coated fabrics.

405

Glossary of Terms

ASTM D570: An American Society for Testing of Materials standard method for determining the relative rate of water absorption of immersed plastics. The test applies to all kinds of plastics: molded, cast, laminated, etc. The specimens are immersed for 2– 24 hours or until saturation at ambient temperature, or for 0.5–2 hours in boiling water. The absorption is calculated as a percentage of weight gain.

of a carbon arc lamp simulating the sunlight with or without strain and sprayed with water for 18 minutes every 102 minutes. Testing may be carried out in the presence of ozone. The aging is evaluated after a specified duration of exposure by determining the percentage decrease in tensile strength and elongation at break, and by observing the extent of surface crazing and cracking.

ASTM D638: An American Society for Testing of Materials standard method for determination of the tensile properties of unreinforced and reinforced plastics in the form of standard dumbbell-shaped specimens under defined conditions of pretreatment, temperature, humidity, and testing machine speed. Note: Tensile properties determined include tensile stress (strength) at yield and at break, percentage elongation at yield or at break, and modulus of elasticity. Also called ASTM method D638-84. See also tensile strength.

ASTM D1003: An American Society for Testing of Materials standard method for measuring the haze and luminous transmittance of transparent plastics using a hazemeter or spectrophotometer.

ASTM D638: An American Society for Testing of Materials standard method for determining the tensile strength, elongation, and modulus of elasticity of reinforced or unreinforced plastics in the form of sheets, plates, moldings, rigid tubes, and rods. Five (I–V) types, depending on dimensions, of dumbbell-shaped specimens with thickness not exceeding 14 mm are specified. Specified speed of testing varies depending on the specimen type and plastic rigidity. Also called ASTM D638, type IV. ASTM D638, type IV: See ASTM D638. ASTM D746: An American Society for Testing of Materials standard method for determining the brittleness temperature of plastics and elastomers by impact. The brittleness temperature is the temperature at which 50% of cantilever beam specimens fail on impact of a striking edge moving at a linear speed of 1.8–2.1 m/s and striking the specimen at a specified distance from the clamp. The temperature of the specimen is controlled by placing it in a heattransfer medium, the temperature of which (usually subfreezing) is controlled by a thermocouple. ASTM D750: An American Society for Testing of Materials standard method for the testing of rubber deterioration in carbon-arc or weathering apparatus. Vulcanized rubber specimens are exposed to the light

ASTM D-1925-63T: See ASTM D1925. ASTM D1006: An American Society for Testing of Materials standard practice for conducting exterior exposure tests of house and trim paints on new wood. Painted testing panels (boards or plywood) are exposed for several years on vertical fences facing both north and south and visually examined for failures at prescribed intervals (1–6 months). ASTM D1171: An American Society for Testing of Materials standard method for determining the resistance of rubber to outdoor weathering and to surface ozone cracking in a special chamber. The specimens with triangular cross sections are mounted strained around circular mandrels and exposed outdoors for a specified period of time or in the chamber for 72 hours at about 40ºC and ozone partial pressure of about 50 MPa. After the exposure the specimens are compared to the reference standards to evaluate the degree of cracking in terms of a rating. Also called ASTM D1171 Loop. ASTM D1171 Loop: See ASTM D1171. ASTM D1435: An American Society for Testing of Materials standard practice for outdoor weathering of plastics. The specimens are mounted on special racks at different tilts and exposed outdoors for an extended period of time while the solar radiation, temperature, rainfall, etc., are measured. The weathering of the specimens is assessed visually and by measuring the changes in color, surface, mechanical (e.g., hardness and tensile strength), and other properties.

406

The Effects of UV Light and Weather on Plastics and Elastomers

ASTM D1499: An American Society for Testing of Materials standard practice for operating lightand water-exposure apparatus for plastics. The specimens are exposed to light from a carbon arc lamp and intermittent water spray (18 minutes every 2 hours) at about 63◦ C for 720 hours. The degradation of the specimens is assessed visually and by measuring the changes in surface, color, mechanical (e.g., hardness and tensile strength), and other properties. ASTM D1708: An American Society for Testing of Materials standard method for determining the tensile properties of plastics using microtensile specimens with a maximum thickness of 3.2 mm and a minimum length of 38.1 mm, including thin films. Tensile properties include yield strength, tensile strength, tensile strength at break, elongation at break, etc., determined as per ASTM D638. ASTM D1925: An American Society for Testing of Materials standard method for determining the yellowness index or its change for clear or white plastics exposed 10 daylight as measured by a spectrophotometer. Also called ASTM D-1925-63T. ASTM D2240: An American Society for Testing of Materials standard method for determining the hardness of materials ranging from soft rubbers to some rigid plastics by measuring the penetration of a blunt (type A) or sharp (type D) indenter of a durometer at a specified force. The blunt indenter is used for softer materials and the sharp indenter for more rigid materials. ASTM D2565: An American Society for Testing of Materials standard practice for operating xenon arctype light exposure apparatus with or without water spray exposure for plastics. The practice specifies the number and the location of xenon arc lamps and other characteristics of the apparatus and the specimens. The xenon arc lamps used may be water- or air-cooled and are equipped with a proper filter to simulate sunlight. The test is conducted for 720 hours at about 63◦ C and at a specified intensity of radiation. The degradation of the specimens is assessed visually and by measuring the changes in surface, color, mechanical (e.g., hardness and tensile strength), and other properties.

ASTM D3679: An American Society for Testing of Materials standard specification for extruded single-wall rigid polyvinyl chloride siding that establishes its physical requirements (dimensions, weight, weatherability, impact resistance, expansion, shrinkage, and appearance) and test methods for physical requirements and marking. ASTM D3763: An American Society for Testing of Materials standard method for determination of the resistance of plastics, including films, to high-speed puncture over a broad range of test velocities using load and displacement sensors. Note: Puncture properties determined include maximum load, deflection to maximum load point, energy to maximum load point, and total energy. Also called ASTM method D3763-86. See also impact energy. ASTM D3841: An American Society for Testing of Materials standard specification for glass fiber-reinforced polyester construction panels. The specification covers classification, inspection, certification, dimensions, weight, appearance, light transmission, weatherability, expansion, impact resistance, flammability, and load-deflection properties of panels and their methods of testing. ASTM D4141: An American Society for Testing of Materials standard practice for conducting accelerated outdoor exposure tests for evaluating exterior durability of coatings applied to metal substrates. The degradation of coatings is accelerated by maximizing the temperature, using a heated (Procedure B) or unheated (Procedure A) black box panel, or by maximizing sunlight irradiation, using a Fresnel reflector (Procedure C) panel. A black box panel is a coated metal panel mounted as a closure on a black box to simulate the conditions on the hoods, roofs, and deck leads of automobiles parked in direct sunlight. The degradation of the specimens is evaluated by measuring loss of gloss, discoloration, checking, cracking, chalking, and blistering.Also calledASTM D4141-A&B. ASTM D4141-A&B: See ASTM D4141. ASTM D4275: An American Society for Testing of Materials standard method for determination of butylated hydroxytoluene in ethylene polymers and

407

Glossary of Terms

ethylene-vinyl acetate copolymers by solvent extraction followed by gas chromatographic analysis. Detection of butylated hydroxytoluene is achieved by flame ionization. Butylated hydroxytoluene is a stabilizer used in the manufacture of the ethylene polymers.

ASTM DS D4434: See ASTM D4434. ASTM DS D4637: See ASTM D4637. ASTM E42: See ASTM G23. ASTM E42-57: See ASTM G23.

ASTM D4434: An American Society for Testing of Materials standard specification for polyvinyl chloride sheet roofing, used as a single-ply roof membrane. The material may be unreinforced or reinforced and may contain fibers or fabrics. The specification specifies types, dimensions, mechanical properties, weatherability, resistance to heat aging, appearance, and test methods. The mechanical properties tested include tensile strength and elongation at break, seam strength, tear resistance, and tearing strength. The exposure tests include accelerated weathering, water exposure, xenon arc light exposure, and fluorescent UV/condensation exposure. Also called ASTM DS D4434. ASTM D4637: An American Society for Testing of Materials standard specification for unreinforced or fabric-reinforced vulcanized rubber sheets made from EPDM or chloroprene rubber and used as single-ply roof membranes. The specification specifies grades, dimensions, mechanical properties, weatherability, resistance to ozone and heat aging, appearance, and test methods. The mechanical properties tested include tensile strength, set and elongation, seam strength, tear resistance, and tearing strength. The exposure tests include water absorption. Also called ASTM DS D4637. ASTM D5071: An American Society for Testing of Materials standard practice for operating xenon arc-type light exposure apparatus with water spray exposure of photodegradable plastics. The practice specifies the type and irradiance capability of xenon arc lamps and other characteristics of the apparatus and the specimens. The xenon arc lamps used must have a proper filter to simulate sunlight. The test is conducted for a specified time at about 63◦ C and a specified intensity of radiation. Alternating light and dark periods with moisture test programs are recommended. The degradation of the specimens is assessed visually and by measuring the changes in surface, color, mechanical (e.g., hardness and tensile strength), and other properties.

ASTM E313: An American Society for Testing of Materials standard method for determination of the indexes of whiteness and yellowness of near-white, opaque materials such as textiles, paints, and plastics. The whiteness or yellowness indexes are one-scale colorimetric attributes measured with a spectrophotometer or a colorimeter having green and blue source-filter-photodetector combination. The yellowness index is calculated as 100(1 − B/G), where B is the blue light reflectance and G is the daylight luminous reflectance of the specimen. The whiteness index is calculated as 4B − 3G. G and B are proportional to the light flux reflected by the specimen for the CIE Source C when viewed under specified geometric conditions by a receptor whose spectral response duplicates the luminosity function y and z, respectively. ASTM E838: See ASTM G90. ASTM E896: An American Society for Testing of Materials standard method for determination of photolysis rates, quantum yields, and phototransformation products of materials that absorb light directly (without the presence of light sensitizers) in aqueous media to estimate the environmental rates of photolysis (i.e., light-induced changes in the structure of a molecule). A three-tier system of testing of increasing complexity is employed. The simplest, tier I test involves the measurement of the concentration of residual material in aqueous solution after up to 6 hours of sunlight exposure. In the tier II test, photolysis rate and rate constants are determined, and in the tier III test phototransformation products. Also called ASTM E896-92. ASTM E896-92: See ASTM E896. ASTM G7: An American Society for Testing of Materials standard practice for atmospheric environmental exposure (weathering) testing of nonmetallic materials. The practice specifies test variables that

408

The Effects of UV Light and Weather on Plastics and Elastomers

are important to produce consistent results. These variables include exposure location; type, position, and construction of specimen panel racks; instrumentation for determining climatological data such as relative humidity; and type and duration of exposure. The types of exposure include direct weathering, exposure behind glass, sheltered storage, and undercover and warehouse exposure. The changes in specimens are evaluated by rating against standards. ASTM G23: An American Society for Testing of Materials standard practice for operating lightexposure apparatus with or without water spray for determination of lightfastness of nonmetallic materials. The specimens are exposed to light from a carbon arc lamp with or without alternating periods of darkness and intermittent water spray at about 63◦ C for a specified extended period of time. The apparatus (weatherometers) used are as follows: type D—twin enclosed carbon-arc lamp apparatus with rotating specimen drum, type E—single open-flame sunshine carbon-arc lamp apparatus with rotating specimen rack, type H—single enclosed carbon-arc lamp apparatus with rotating specimen rack. The degradation of the specimens is assessed visually and by measuring the changes in color, surface, mechanical (e.g., hardness and tensile strength), and other properties. Also called ASTM E42, ASTM E42-57. ASTM G26: An American Society for Testing of Materials standard practice for operating lightexposure apparatus with or without water spray for determination of lightfastness of nonmetallic materials. The specimens are exposed to light from a xenon arc lamp with or without alternating periods of darkness and intermittent water spray at about 63◦ C for a specified extended period of time. The apparatus (weatherometers) used are as follows: type A and B—water-cooled long-arc vertical xenon lamp with borosilicate glass filters, type C and D—single air-cooled xenon-arc lamp apparatus with IR optical filters, type E—triple xenon-arc lamp apparatus with ER optical filters. The degradation of the specimens is assessed visually and by measuring the changes in color, mechanical (e.g., impact and tensile strength), and other properties. ASTM G53: An American Society for Testing of Materials standard practice for operating light- and water-exposure apparatus for determination of the

resistance to deterioration of nonmetallic materials exposed to sunlight and water as rain and dew. The specimens are exposed alternately to light from a fluorescent UV lamp and to condensation in a repetitive cycle. Condensation, is produced by exposing one surface of the specimen to a heated, saturated mixture of air and water vapor, while cooling the opposite surface. The degradation of the specimens is assessed visually and by measuring the changes in color, surface, mechanical (e.g., hardness and tensile strength), and other properties. ASTM G85: An American Society for Testing of Materials standard practice for modified salt spray (fog) testing of materials such as metals, metallic coatings, and nonmetallic coatings on metal substrates. The method sets forth the conditions for evaluating anticorrosive properties of materials exposed to a fine spray of a saline solution at about 35◦ C in a special chamber for an extended period of time. The test may be continuous or cyclic. The saline solution may be acetic acid-NaCl solution (pH 3.1–3.3), acidified seawater or SO2 -NaCl solution. The results are assessed visually by checking for a specified extent of corrosion damage or by a measuring technique such as impedance. ASTM G90: An American Society for Testing of Materials standard practice for performing accelerated outdoor weathering of nonmetallic materials using natural sunlight concentrated by a Fresnel reflector without (type A) or with (type B) a periodic water spray to simulate arid or humid climatic conditions. The Fresnel reflector machine comprises a system of flat mirrors that follows the sun with the help of two photoreceptor cells to maximize irradiation and temperature of specimen panels and accelerate weathering. The total solar radiation does is reported. The degradation of the specimens is assessed visually and by measuring the changes in color, surface, mechanical (e.g., hardness and tensile strength), and other properties. Also called ASTM E838. ASTM method D256-84: See ASTM D256. ASTM method D3763-86: See ASTM D3763. ASTM method D638-84: See ASTM D638.

409

Glossary of Terms

Atlas Ci65 xenon arc weatherometer: See xenon arc weatherometer.

steel panel as specified in ASTM G26. It is used as the standard reference to control an indoor lightexposure test temperature.

Atlas fadeometer: See fadeometer. Atlas UV-CON: See fluorescent condensation apparatus.

UV

lamp-

azo: A prefix indicating an organic group of two nitrogen atoms linked by a double bond, –N=N–, or a class of chemical compounds containing this group, like azo dyes.

B backed exposure rack: A rack for holding specimens or specimen panels during exposure testing that is enclosed from the back to better control the effect of exposure on the exposed side of the specimen.

bleaching: Complete loss of color of the material as a result of degradation or removal of colored substances present on its surface. Bleaching can be caused by chemical reactions, radiation, etc. blistering: The formation of bubbles on the surface of a nonmetallic coating or a plastic specimen or article as a result of air or other gases or evaporation of moisture or other volatiles trapped beneath. Blistering is often caused by improper application or excessive mixing of paints, heat, and polymer degradation.

bending strength: See flexural strength.

borosilicate outer filter: A borosilicate glass outer filter of a xenon-arc lamp that in combination with a soda-lime or quartz inner filter selectively screens radiation output, especially in the short UV wavelength region, to simulate the window glass-filtered daylight and sunlight, respectively, in an accelerated light exposure testing apparatus.

bending stress: See flexural stress.

breaking elongation: See elongation.

benzotriazoles: A family of UV absorbers for plastics and rubbers, comprising derivatives of 2(2 -hydroxyphenyl)benzotriazole. They offer strong intensity and broad UV absorption with fairly sharp wavelength cutoff close to the visible region. Higher alkyl derivatives arc less volatile and therefore more suitable for higher temperature processing.

bubbling: The presence of bubbles of trapped air and/or volatile vapors in nonmetallic coatings or plastic specimens or articles. Bubbling is often caused by improper application or excessive mixing of paints or degassing.

bending properties: See flexural properties.

C biodegradation: Microorganism-induced degradation of the material that may involve a negative effect such as loss of performance and cracking of an underground pipe or a positive effect such as decomposition of material waste to simple chemical compounds. Usually, the microorganisms such as fungi induce biodegradation by generating the enzymes and proteins that catalyze degradation reactions. Also called microbiological attack.

C.I. Pigment Orange 20: See cadmium orange. C.I. Pigment Red 108: See cadmium red. C.I. Pigment Yellow 37:1: See lithopone yellow. CA: See cellulose acetate. CAB: See cellulose acetate butyrate.

bisphenol A polyester: A thermoset unsaturated polyester based on bisphenol A and fumaric acid. black panel temperature: Temperature measured by sensors mounted on the black-coated stainless

cadmium orange: An orange nonbleeding inorganic pigment based on cadmium sulfide and sulfoselenide (Color Index Number 77202), having high lightfastness and good heat and alkali resistance.

410

The Effects of UV Light and Weather on Plastics and Elastomers

Used in PVC and polyolefin plastics, paints, and high-gloss baking enamels. Also called C.I. Pigment Orange 20. cadmium red: A red nonbleeding inorganic pigment based on cadmium sulfide and sulfoselenide (Color Index Number 77202), having high lightfastness and good heat and alkali resistance. Used in PVC and polyolefin plastics, paints, and high-gloss baking enamels. Also called CP cadmium red, C.I. Pigment Red 108. cadmium yellow: A yellow nonbleeding inorganic pigment based on cadmium sulfide and sulfoselenide (Color Index Number 77202), having high lightfastness and good heat and alkali resistance. Used in PVC and polyolefin plastics, paints, and high-gloss baking enamels. carbon arc weatherometer: An apparatus for accelerated indoor weatherability testing of materials such as plastics. Equipped with one to two enclosed or open-flame carbon arc lamps with borosilicate glass filters to simulate the sunlight and with a water spraying device. The lamps used in this apparatus have unnaturally high irradiance in the short wavelength region, especially at 390 nm. As a result it produces less realistic degradation than xenon arc apparatus. Most models allow controlling and monitoring temperature and humidity inside the apparatus as well as alternating dark and light cycles of exposure. carbon black: A black colloidal carbon filler made by the partial combustion or thermal cracking of natural gas, oil, or another hydrocarbon. There are several types of carbon black depending on the starting material and the method of manufacture. Each type of carbon black comes in several grades. Carbon black is widely used as a filler and pigment in rubbers and plastics. It reinforces, increases the resistance to UV light, reduces static charging. cellulose acetate: Thermoplastic esters of cellulose with acetic acid. Have good toughness, gloss, clarity, processability, stiffness, hardness, and dielectric properties, but poor chemical, fire and water resistance, and compressive strength. Processed by injection and blow molding and extrusion. Used for appliance cases, steering wheels, pens, handles, containers, eyeglass frames, brushes, and sheeting. Also called CA.

cellulose acetate butyrate: Thermoplastic mixed esters of cellulose with acetic and butyric acids. Have good toughness, gloss, clarity, processability, dimensional stability, weatherability, and dielectric properties, but poor chemical, fire and water resistance, and compressive strength. Processed by injection and blow molding and extrusion. Used for appliance cases, steering wheels, pens, handles, containers, eyeglass frames, brushes, and sheeting. Also called CAB. cellulose propionate: Thermoplastic esters of cellulose with propionic acid. Have good toughness, gloss, clarity, processability, dimensional stability, weatherability, and dielectric properties, but poor chemical, fire and water resistance, and compressive strength. Processed by injection and blow molding and extrusion. Used for appliance cases, steering wheels, pens, handles, containers, eyeglass frames, brushes, and sheeting. Also called CP. cellulosic plastics: Thermoplastic cellulose esters and ethers. Have good toughness, gloss, clarity, processability, and dielectric properties, but poor chemical, fire and water resistance, and compressive strength. Processed by injection and blow molding and extrusion. Used for appliance cases, steering wheels, pens, handles, containers, eyeglass frames, brushes, and sheeting. Chaetomium globosum: A species of common mold belonging to the genus Chaetomium. Used alone or in artificial mixtures with other fungi to prepare cultures for the testing of mildew resistance of materials such as plastics, or fungicidal activity of antimildew agents or fungicides. chain scission: Breaking of the chain-like molecule of a polymer as a result of chemical, photochemical, etc., reactions such as thermal degradation or photolysis. chalking: Formation of a dry, chalk-like, loose powder on or just beneath the surface of a paint film or plastic caused by the exudation of a compounding ingredient such as pigments, often as a result of ingredient migration to the surface and surface degradation.

411

Glossary of Terms

channel black: Carbon black made by impingement of a natural gas flame against a metal plate or channel iron, from which a deposit is scraped. Used as a reinforcing filler in rubbers. Also called gas black. checking: A defect on the surface of a topcoat paint manifesting itself by slight breaks in the film so that underlying coats are visible. Some checks are so small that they are invisible without magnification. Also called surface checks. chemical saturation: Absence of double or triple bonds in a chain organic molecule such as that of most polymers, usually between carbon atoms. Saturation makes the molecule less reactive and polymers less susceptible to degradation and cross-linking. Also called chemically saturated structure. chemical unsaturation: Presence of double or triple bonds in a chain organic molecule such as that of some polymers, usually between carbon atoms. Unsaturation makes the molecule more reactive, especially in free-radical addition reactions such as addition polymerization, and polymers more susceptible to degradation, cross-linking, and chemical modification. Also called polymer chain unsaturation. chemically saturated structure: See chemical saturation. chlorendic polyester: A chlorendic anhydridebased unsaturated polyester. chlorinated polyvinyl chloride: Thermoplastic produced by chlorination of PVC. Has increased glass transition temperature, chemical and fire resistance, rigidity, tensile strength, and weatherability compared to PVC. Processed by extrusion, injection molding, casting, and calendering. Used for pipes, auto parts, waste disposal devices, and outdoor applications. Also called CPVC. chloroethyl alcohol(2-): See ethylene chlorohydrin. chlorohydrins: Halohydrins with chlorine as a halogen atom. One of the most reactive of halohydrins. Dichlorohydrins are used in the preparation of epichlorohydrins, important monomers in the

manufacture of epoxy resins. Most chlorohydrins are reactive colorless liquids, soluble in polar solvents such as alcohols. Note: Chlorohydrins are a class of organic compounds, not to be mixed up with a specific member of this class—l-chloropropane-2,3diol, which sometimes called chlorohydrin. chlorosulfonated polyethylene rubber: setting elastomers containing 20–40% Have good weatherability and heat and resistance. Used for hoses, tubes, sheets, soles, and inflatable boats.

Thermochlorine. chemical footwear

chrome green: A green inorganic pigment consisting mainly of lead chromate and used in paints, rubbers, and plastics. Chrome green has good lightfastness, brightness, weatherability, and chemical resistance. Chromophtal green: A green organometallic pigment based on chromium phthalocyanine. Chromophtal red: A red organometallic pigment based on chromium phthalocyanine. Ci65 xenon arc weatherometer: See xenon arc weatherometer. coated molybdate: See coated molybdate orange pigment. coated molybdate orange pigment: Solid solutions of lead chromate, lead molybdate, and lead sulfate used as dark orange to light red inorganic pigments for plastics. When coated with silica these pigments exhibit high hiding power, brightness, lightfastness, thermal stability, and resistance to bleeding. Also called coated molybdate. cocatalyst: See accelerator. color: The wavelength composition of light, specifically of the light reflected or emitted by the material and its visual appearance (red, blue, etc.). Also called hue, tint, coloration. Color stability is quantified and reported as E. color change: See discoloration. color concentrate let down: Reducing the intensity or depth of the color of a concentrated colored

412

The Effects of UV Light and Weather on Plastics and Elastomers

pigment dispersion (or paste) in a vehicle (water, binder, or solvent) by the addition of a white, or sometimes colorless, pigment.

weatherability testing, without accelerating the process by using above normal temperature, irradiation, etc.

color difference: The square root of the sum of the squares of the chromaticity difference and the lightness difference. Also called E, E color change.

conventional aging with spray: Prolonged exposure of materials such as plastics to natural or artificial environmental conditions, including water or salt spray, to produce degradation as in weatherability testing, without accelerating the process by using above normal temperature, irradiation, etc.

color masking agent: See masking filler. coloration: See color. colorimeter: An optical instrument for determining or matching colors. The sample’s color is matched visually with the color resulting from the superposition of the light that passes through three primary color filters adjusted to transmit a varying amount of light. Or, an optical instrument for determining the concentration of a colored solution by comparing its absorbance in a certain wavelength region with that of a standard solution with known concentration. Also called Hunter Colorimeter. composite spore suspension: A mixture of spores of different fungus species suspended in culture media and used for testing the mildew resistance of materials such as paints and plastics and the activity of antimildew agents and fungicides. concentration units: The units for measuring the content of a distinct material or substance in a medium other than this material or substance, such as a solvent. Note: The concentration units are usually expressed in the units of mass or volume of substance per one unit of mass or volume of medium. When the units of the substance and the medium are the same, the percentage is often used. conditioning: Process of bringing the material or apparatus to a certain condition (e.g., moisture content or temperature) prior to further processing, treatment, etc. Also called conditioning cycle. conditioning cycle: See conditioning. conventional aging: Prolonged exposure of materials such as plastics to natural or artificial environmental conditions to produce degradation as in

covulcanization: Simultaneous vulcanization of a blend of two or more different rubbers to enhance their individual properties such as ozone resistance. Rubbers are often modified to improve covulcanization. CP: See cellulose propionate. CP cadmium red: See cadmium red. CPVC: See chlorinated polyvinyl chloride. cracking: Appearance of external and/or internal cracks in the material as a result of stress that exceeds the strength of the material. The stress can be external and/or internal and can be caused by a variety of adverse conditions: structural defects, impact, aging, corrosion, etc., or a combination of these conditions. Also called cracks. See also processing defects. cracks: See cracking. crazes: See crazing. crazing: Appearance of thin cracks on the surface of the material or, sometimes, minute frost-like internal cracks, as a result of stress that exceeds the strength of the material. The stress can be caused by a variety of adverse conditions: impact, temperature changes, degradation, etc. Also called crazes. cross-linked polyethylene: Polyethylene thermoplastics that are partially photochemically or chemically cross-linked. Have improved tensile strength, dielectric properties, and impact strength at low and elevated temperatures. cross-linking: Reaction resulting in the formation of covalent bonds between chain-like polymer

413

Glossary of Terms

molecules or between polymer molecules and lowmolecular compounds such as carbon black fillers. As a result of cross-linking polymers, such as thermosetting resins, may become hard and infusible. Cross-linking is induced by heat, UV or electronbeam radiation, oxidation, etc. Cross-linking can be achieved either between polymer molecules alone as in unsaturated polyesters or with the help of multifunctional cross-linking agents such as diamines that react with functional side groups of the polymers. Cross-linking can be catalyzed by the presence of transition metal complexes, thiols, and other compounds. crystal polystyrene: See polystyrene.

general

dart drop impact strength: See falling weight impact energy. decoloration: Complete or partial loss of color of the material as a result of degradation or removal of colored substances present in it. Also called decoloring. decoloring: See decoloration. defects: See processing defects. deflection temperature under load: See heat deflection temperature.

purpose

CTFE: See polychlorotrifluoroethylene. CTH-Glas Trac: A sun-tracking, automotive glasscovered cabinet for accelerated outdoor weathering of automotive interior materials. The air temperature inside the cabinet is controlled and usually maintained at 70◦ C during daylight hours and 38°C during night. The relative humidity during night is controlled and usually maintained at 75%. Produced by Heraeus DSET Laboratories, Inc., Phoenix, Arizona. cycle time: See processing time. cyclic compounds: A broad class of organic compounds consisting of carbon rings that are saturated, partially unsaturated, or aromatic, in which some carbon atoms may be replaced by other atoms such as oxygen, sulfur, and nitrogen. D DAP: See diallyl phthalate resins. dark cycle: In weathering and light exposure testing that simulates outdoor environments, a period when the specimen is not irradiated, which alternates with the period of irradiation. dart drop impact: See falling weight impact energy. dart drop impact energy: See falling weight impact energy.

degradation: Loss or undesirable change in the properties, such as color, of a material as a result of aging, chemical reaction, wear, exposure, etc. See also stability. E: See color difference. E color change: See color difference. dew cycle: In light and water exposure testing that simulates outdoor environments, a period when the specimen is exposed to condensation instead of radiation, which alternates with the period of irradiation. Condensation is produced by exposing one surface of the specimen to a heated, saturated mixture of air and water vapor, while cooling the opposite surface. diallyl phthalate resins: Thermosets supplied as diallyl phthalate prepolymers or monomers. Have high chemical, heat and water resistance, dimensional stability, and strength. Shrink during peroxide curing. Processed by injection, compression, and transfer molding. Used in glass-reinforced tubing, auto parts, and electrical components. Also called DAP. dihydric alcohols: See glycols. dihydroxy alcohols: See glycols. DIN 6167: A German Standard Institute standard specifying conditions for determination of the yellowness (yellowness index) of near-white or nearcolorless materials such as plastics and nonmetallic coatings.

414

The Effects of UV Light and Weather on Plastics and Elastomers

DIN 50031: A German Standards Institute standard specifying conditions for salt spray testing of anticorrosive properties of materials such as metallic and nonmetallic coatings on metal substrates. The specimens are exposed to a fine spray of a NaCl (5 g/100 mL), acetic acid-NaCl (pH 3.1–3.4), or CuCu12 -acetic acid-NaCl (CASS lest, pH 3.1–3.4) solution at about 35◦ C in a special chamber for 96 hours. The results are assessed by measuring the rate of corrosion (i.e., weight loss per unit area of the test panel). DIN 53231: A German Standards Institute standard specifying conditions for artificial weathering (with wetting) and aging (without wetting) of coatings by exposure to filtered xenon-arc lamp irradiation. The specimens are exposed to 550 W/m3 average hourly irradiance at 290–800 nm wavelength with (method 1) or without (method 2) wetting and filtering of the light through a 3-mm thick window glass at 40–60% relative humidity. For method 1, rain is simulated by immersion or spraying and condensation is simulated by spraying the back of the test panels with cold water. The wetting may be continuous or periodic with 102- or 17-minute dry periods. The degradation of the specimens is assessed visually and by measuring the changes in color, mechanical (e.g., impact and tensile strength), and other properties. Also called DIN 53231 method I, DIN 53231 method 2. DIN 53231 method 1: See DIN 53231. DIN 53231 method 2: See DIN 53231. DIN 53387: A German Standards Institute standard specifying conditions for artificial weathering (with wetting) and aging (without wetting) of plastics and elastomers by exposure to filtered xenon-arc lamp irradiation. The specimens are exposed to 550 W/m3 average hourly irradiance at 290–800 nm wavelength with (method 1) or without (method 2) wetting and filtering of the light through a 3-mm thick window glass at 40–60% relative humidity. For method 1, rain is simulated by immersion or spraying and condensation is simulated by spraying the back of the test panels with cold water. The wetting may be continuous or periodic with 102- or 17-minute dry periods. The degradation of the specimens assessed visually and by measuring

the changes in color, mechanical (e.g., impact and tensile strength), and other properties. Also called DIN 53387 method 1, DIN 53387 method 2. DIN 53387 method 1: See DIN 53387. DIN 53387 method 2: See DIN 53387. DIN 53388: A German Standards Institute standard specifying conditions for the testing of resistance to degradation of plastics and elastomers exposed to window glass-filtered daylight. Also called ISO 877, DIN 53388 scale. DIN 53388 scale: See DIN 53388. DIN 53453: A German Standards Institute standard specifying conditions for the flexural impact testing of molded or laminated plastics. The bar specimens are either unnotched or notched on one side, mounted on a two-point support, and struck in the middle (on the unnotched side for notched specimens) by a hammer of the pendulum impact machine. The impact strength of the specimen is calculated relative to the cross-sectional area of the specimen as the energy required to break the specimen equal lo the difference between the energy in the pendulum at the instant of impact and the energy remaining after complete fracture of the specimen. Also called DIN 53453 impact test. DIN 53453 impact test: See DIN 53453. DIN 54001: A German Standards Institute standard specifying conditions for the preparation and use of gray scale for assessing the change in color during accelerated testing of colorfastness of dyed and printed textiles. Also called ISO 105-A02. DIN 54003: German Standards Institute standard specifying conditions for the accelerated testing of colorfastness of interior materials in motor vehicles to light by irradiation with a glass-filtered xenonarc lamp. Also called DIN 54003 (FAKRA), ISO 105-B06. DIN 54003 (FAKRA): See DIN 54003. DIN 54004: A German Standards Institute standard specifying conditions for the accelerated testing of

415

Glossary of Terms

colorfastness of dyed and printed textiles to light by irradiation with a xenon-arc fading lamp. Also called ISO 105-B04.

and accelerated weatherability testing services and equipment.

DIN 54071: A German Standards Institute standard specifying conditions for the accelerated testing of colorfastness of dyed and printed textiles to weather by irradiation with a xenon-arc lamp. Also called ISO 105-B04.

E

discoloration: A change in color due to chemical or physical changes in the material. Also called color change. disperse dyes: Nonionic dyes insoluble in water and used mainly as fine aqueous dispersions in dying acetate, polyester, and polyamide fibers. A large subclass of disperse dyes comprises lowmolecular-weight aromatic azo compounds with amino, hydroxy, and alkoxy groups that fix on fibers by forming Van der Waals and hydrogen bonds.

ECTFE: See copolymer.

ethylene-chlorotrifluoroethylene

elongation: The increase in gauge length of a specimen in tension, measured at or after the fracture, depending on the viscoelastic properties of the material. Note: Elongation is usually expressed as a percentage of the original gauge length. Also called tensile elongation, elongation at break, ultimate elongation, breaking elongation, elongation at rupture. See also tensile strain. elongation at break: See elongation. elongation at rupture: See elongation. EMAC: See ethylene-methyl acrylate copolymer.

displacement: Process of removing one object (e.g., a medium in an apparatus) or its part and replacing it with another. Also called displacement cycle.

embrittlement: A reduction or low of ductility or toughness in materials such as plastics resulting from chemical or physical damage.

displacement cycle: See displacement.

EMMA: See equatorial mount with mirrors for acceleration.

double carbon arc weatherometer: An apparatus for accelerated indoor testing of weatherability of materials such as plastics. Equipped with a carbon arc lamp having a combination of neutral solid and cored electrodes enclosed in a borosilicate glass filter to simulate sunlight and with a water spraying device. Most models allow controlling and monitoring temperature and humidity inside the apparatus as well as alternating dark and light cycles of exposure. drop weight impact: See falling weight impact energy. drop weight impact energy: See falling weight impact energy. drop weight impact strength: See falling weight impact energy. DSET: Heraeus DSET Laboratories, Inc. A Phoenix, Arizona, company specializing in conventional

EMMAQUA: See equatorial mount with mirrors for acceleration plus water spray. enclosed carbon arc: See enclosed carbon arc lamp. enclosed carbon arc lamp: A light source for accelerated indoor weatherability testing of materials such as plastics that consists of a carbon arc enclosed in a borosilicate glass filter for short wavelengths to simulate sunlight. The enclosed carbon arc lamps have unnaturally high irradiance in the short wavelength region, especially at 390 nm. As a result they produce less realistic degradation than xenon arc lamps. Also called enclosed carbon arc. energy quencher: A low-molecular weight organic compound such as a polycyclic aromatic compound that retards ionizing radiation-induced polymer degradation by scavenging or trapping part of

416

The Effects of UV Light and Weather on Plastics and Elastomers

excited-state energy of the polymer without undergoing significant chemical change due to the highly efficient decay of its own excited states. Also called energy quencher additives, energy scavenger.

EPR: See ethylene-propene rubber.

energy quencher additives: See energy quencher.

equatorial mount with mirrors and water spray: See equatorial mount with mirrors for acceleration plus water spray.

energy scavenger: See energy quencher. EPDM: See EPDM rubber. EPDM rubber: Sulfur-vulcanizable thermosetting elastomers produced from ethylene, propylene, and a small amount of a nonconjugated diene such as hexadiene. Have good weatherability and chemical and heat resistance. Used as impact modifiers and for weather stripping, auto parts, cable insulation, conveyor belts, hoses, and tubing. Also called EPDM. epoxides: Organic compounds containing threemembered cyclic group(s) in which two carbon atoms are linked with an oxygen atom as in an ether. This group is called an epoxy group and is quite reactive, allowing the use of epoxides as intermediates in the preparation of certain fluorocarbons and cellulose derivatives, and as monomers in the preparation of epoxy resins. Also called epoxy compounds. epoxies: See epoxy resins. epoxy compounds: See epoxides. epoxy resins: Thermosetting polyethers containing cross-linkable glycidyl groups. Usually prepared by the polymerization of bisphenol A and epichlorohydrin or reacting phenolic novolaks with epichlorohydrin. Can be made unsaturated by acrylation. Unmodified varieties are cured at room or elevated temperatures with polyamines or anhydrides. Bisphenol A epoxy resins have excellent adhesion and very low shrinkage during curing. Cured novolak epoxies have good UV stability and dielectric properties. Cured acrylated epoxies have high strength and chemical resistance. Processed by molding, casting, coating, and lamination. Used as protective coatings, adhesives, potting compounds, and binders in laminates and composites. Also called epoxies. epoxyethane: See ethylene oxide.

equatorial mount with mirrors: See equatorial mount with mirrors for acceleration.

equatorial mount with mirrors for acceleration: An accelerated outdoor weathering test method developed by Heraeus DEST Laboratories, Inc., for exterior materials with equatorial mount of specimen panels and reflector mirrors to increase solar irradiation. The equatorial mount means that the specimen panels are continuously maintained in the position facing and normal to the sun. The mirrors follow the sun for maximum reflection. Also called EMMA, equatorial mount with mirrors. equatorial mount with mirrors for acceleration plus water spray: An accelerated outdoor weathering test method developed by Heraeus DEST Laboratories, Inc., for exterior materials with equatorial mount of specimen panels and reflector mirrors to increase solar irradiation and water spray to simulate humid climate. The equatorial mount means that the specimen panels are continuously maintained in the position facing and normal to the sun. The mirrors follow the sun for maximum reflection. Also called EMMAQUA, equatorial mount with mirrors and water spray. ETFE: See ethylene-tetrafluoroethylene copolymer. ethanediol(1,2-): See ethylene glycol. ethers: A class of organic compounds in which an oxygen atom is interposed between two carbon atoms in a chain or ring. Ethers are derived mainly by the catalytic of olefins. The lower molecular weight ether are dangerous fire and explosion hazards. Note: Major types of ethers include aliphatic, cyclic, and polymeric ethers. ethylene-acrylic rubber: Copolymers of ethylene and acrylic esters. Have good toughness, low temperature properties, and resistance to heat, oil, and water. Used in auto and heavy equipment parts.

417

Glossary of Terms

ethylene alcohol: See ethylene glycol. ethylene chlorohydrin (C2 H5 ClO): Ethylene chlorohydrin, ClCH2 CH2 OH, is a colorless liquid that is easily soluble in most organic liquids and water. It has an autoignition temperature of 450◦ C (797◦ F) and is a moderate fire hazard. Derived by the reaction of hydrochlorous acid with ethylene. It is a strong irritant, deadly via inhalation, skin absorption, etc., with a TLV of 1 ppm in air. Penetrates through rubber gloves. Used as a solvent for cellulose derivatives, intermediate in organic synthesis (e.g., for ethylene oxide), and sprouting activator. Note: Hydrolysis of ethylene oxide during sterilization can result in the formation of ethylene chlorohydrin and its residual presence in sterilized goods. Also called 2-chloroethyl alcohol. glycol chlorohydrin. See also chemical sterilization agent hydrolysis products. ethylene copolymers: See ethylene polymers. ethylene-methyl acrylate copolymer: Thermoplastic copolymers of ethylene with <40% methyl acrylate. Have good dielectric properties, toughness, thermal stability, stress crack resistance, and compatibility with other polyolefins. Transparency decreases with increasing content of acrylate. Processed by blow film extrusion and blow and injection molding. Used in heat-sealable films, disposable gloves, and packaging. Some grades are FDAapproved for food packaging. Also called EMAC. ethylene polymers: Ethylene polymers include ethylene homopolymers and copolymers with other unsaturated monomers, most importantly olefins such as propylene and polar substances such as vinyl acetate. The properties and uses of ethylene polymers depend on the molecular structure and weight. Also called ethylene copolymers. ethylene-propene rubber: Stereospecific copolymers of ethylene with propylene. Used is impact modifiers for plastics. Also called EPR. ethylene-tetrafluoroethylene copolymer: Thermoplastic alternating copolymer of ethylene and tetrafluoroethylene. Has good impact strength, abrasion and chemical resistance, weatherability, and dielectric properties. Processed by molding, extrusion, and powder coating. Used in tubing, cables,

pump parts, and tower packing in a wide temperature range. Also called ETFE. ethylene-vinyl alcohol copolymer: Thermoplastics prepared by hydrolysis of ethylene-vinyl acetate polymers. Have good barrier properties, mechanical strength gloss elasticity, weatherability, clarity, and abrasion resistance. Barrier properties and processability improve with increasing content of ethylene due to lower absorption of moisture. Processed by extrusion, coating, blow and film molding, and thermoforming. Used as packaging films and container liners. Also called EVOH. EVOH: See ethylene-vinyl alcohol copolymer. extenders: Relatively inexpensive resin, plasticizer, or filler such as carbonate used to reduce cost and/or to improve processing of plastics, rubbers, or nonmetallic coatings. exterior rutile TiO2 : See exterior rutile titanium dioxide. exterior rutile titanium dioxide: Special grades of rutile titanium dioxide with increased weatherability that are used as a white or opacifying pigment in a wide range of exterior materials including coatings and plastics. Exterior grades of rutile are often chemically modified (e.g., with chromia) to increase their durability. Also called exterior rutile TiO2 . F F40 UVB: See QFS-40 lamp. fade-o-meter: See fadeometer. fadeometer: A light exposure apparatus for accelerated testing of lightfastness of colored materials such as plastics or textiles. The apparatus is equipped with a light source that simulates sunlight but provides a more intense irradiation. Light sources used are carbon- or xenon-arc lamps. Among the manufacturers of fadeometers is Atlas Electric Devices Co., Chicago, Illinois.Also called fade-o-meter, atlas fadeometer. falling dart impact: See falling weight impact energy.

418

The Effects of UV Light and Weather on Plastics and Elastomers

falling dart impact energy: See falling weight impact energy. falling dart impact strength: See falling weight impact energy. falling sand abrasion test: A test for determining abrasion resistance of coatings by the amount of abrasive sand required to wear though a unit thickness of the coating. When sand falls against it at a specified angle from a specified height though a guide tube. Also called falling sand test method. falling sand test method: See falling sand abrasion test. falling weight impact: See falling weight impact energy. falling weight impact energy: The mean energy of a free-falling dart or weight (tup) that will cause 50% failures after 50 tests to a directly or indirectly stricken specimen. The energy is calculated by multiplying dart mass, gravitational acceleration, and drop height. Also called falling weight impact strength, falling weight impact, falling dart impact energy, falling dart impact strength, falling dart impact, dart drop impact energy, dart drop impact strength. falling weight impact strength: See falling weight impact energy. FEP: See fluorinated ethylene-propylene copolymer. Fiberglass: Material made from extremely fine glass fibers. fireproofing agent: See flame retardant. five-membered heterocyclic compounds: A class of heterocyclic compounds containing rings that consist of live atoms. five-membered heterocyclic nitrogen compounds: A class of heterocyclic compounds containing rings that consist of five atoms, some of which are nitrogen.

five-membered heterocyclic oxygen compounds: A class of heterocyclic compounds containing rings that consist of five atoms, some of which are oxygen. flame retardant: A substance that reduce the flammability of materials such as plastics or textiles in which it is incorporated. There are inorganic flame retardants such as antimony trioxide (Sb2 O3 ) and organic flame retardants such as brominated polyols, The mechanisms of flame retardation vary depending on the nature of the material and flame retardant. For example, some flame retardants yield a substantial volume of coke on burning, which prevents oxygen from reaching inside the material and blocks further combustion. Also called fireproofing agent, flame retardant chemical additives, ignition resistant chemical additives. flame retardant chemical additives: See flame retardant. flaw: See processing defects. flexural properties: Properties describing the reaction of physical systems to flexural stress and strain. Also called bending properties. flexural strength: The maximum stress in the extreme fiber of a specimen loaded to failure in bending. Note: Flexural strength is calculated as a function of load, support span, and specimen geometry. Also called modulus of rupture in bending, modulus of rupture, bending strength. flexural stress: The maximum stress in the extreme fiber of a specimen in bending. Note: Flexural stress is calculated as a function of load at a given strain or at failure, support span, and specimen geometry. Also called bending stress. fluorescent sunlamp with dew: See fluorescent UV lamp-condensation apparatus. fluorescent UV lamp-condensation apparatus: An apparatus for accelerated indoor weathering of materials such as plastics equipped with a fluorescent UV-A lamp like UVA-340 that produces an energy spectrum with a peak emission at 340 nm and simulates closely the short wavelength region of solar radiation, or with a fluorescent UV-B lamp like

419

Glossary of Terms

UVB-313 with a peak emission at 313 nm that provides a significantly higher UV radiation output for faster testing. The apparatus is also equipped with a condensation unit that supplies water vapor. The vapor condenses on the surface of the specimen which is cooled from behind to simulate the dew. Among the manufacturers of fluorescent UV lampcondensation apparatus is Atlas Electric Devices Co., Chicago, Illinois, and The Q-Panel Co., Cleveland, Ohio (QUV accelerated weathering tester). Also called fluorescent sunlamp with dew, fluorescent UV-condensation apparatus. Atlas UV-CON, UV-CON, QUV accelerated weathering tester. fluorescent UV-condensation apparatus: See fluorescent UV lamp-condensation apparatus. fluorinated ethylene-propylene copolymer: Thermoplastic copolymer of tetrafluoroethylene and hexafluoropropylene. Has decreased tensile strength and wear and creep resistance, but good weatherability, dielectric properties, fire and chemical resistance, and friction. Decomposes above 204◦ C (400◦ F), releasing toxic products. Processed by molding, extrusion, and powder coating. Used in chemical apparatus liners, pipes, containers, bearings, films, comings, and cables. Also called FEP. fluoro rubber: See fluoroelastomers. fluoroelastomers: Fluorine-containing synthetic rubber with good chemical and heat resistance. Used in underhood applications such as fuel lines, oil and coolant seals, and fuel pumps, and as a flow additive for polyolefins. Also called fluoro rubber. fluoroplastics: See fluoropolymers.

fluorosilicones: Polymers with chains of alternating silicon and oxygen atoms and trifluoropropyl pendant groups. Most are rubbers. FMQ: See methylfluorosilicones. Fourier-transform infrared spectrometry: A spectroscopic technique in which all wavelengths in the infrared region (750–1 × 106 nm) are simultaneously used to irradiate the sample for a short period of time, and the absorption spectrum is found by mathematical manipulation of the Fourier transform (a periodic function) obtained. Also called FTIR analysis. FS-40: See QFS-40 lamp. FS-40 (UV-B) lamps: See QFS-40 lamp. FS-40 lamp: See QFS-40 lamp. FTIR analysis: See Fourier-transform infrared spectrometry. fungus resistance: See mildew resistance. furnace black: The most common type of carbon black made by burning vaporized heavy oil fractions in a furnace with 50% of the air required for complete combustion. It comes in high abrasion, fast extrusion, high modulus, general purpose, semireinforcing, conducting, high elongation, reinforcing, and fast-extruding grades among others. Furnace black is widely used as a filler and pigment in rubbers and plastics. It reinforces, increases the resistance to UV light, and reduces static charging. G gas black: See channel black.

fluoropolymers: Polymers prepared from unsaturated fluorine-containing hydrocarbons. Have good chemical resistance, weatherability, thermal stability, antiadhesive properties, and low friction and flammability, but low creep resistance and strength and poor processibility. The properties vary with the fluorine content. Processed by extrusion and molding. Used as liners in chemical apparatus, in bearings, films, coatings, and containers. Also called fluoroplastics.

general purpose polystyrene: General purpose polystyrene is an amorphous thermoplastic prepared by homopolymerization of styrene. It has good tensile and flexural strengths, high light transmission, and adequate resistance to water, detergents, and inorganic chemicals. It is attached by hydrocarbons and has a relatively low impact resistance. Processed by injection molding and foam extrusion. Used to manufacture containers, health care items

420

The Effects of UV Light and Weather on Plastics and Elastomers

such as pipettes, kitchen and bathroom housewares, stereo and camera parts, and foam sheets for food packaging. Also called crystal polystyrene.

hard clays: Sedimentary rocks composed mainly of fine clay mineral material without natural plasticity, or any compacted or indurated clay.

gloss: The ratio of the light specularly reflected from a surface of material such as plastics or nonmetallic coatings to the total light reflected. The gloss is measured at a specified angle of incidence of light (e.g., 60◦ ). It usually decreases as a result of weathering.

haze: The percentage of transmitted light which, in passing through a plastic specimen, deviates from the incident beam via forward scattering by more that 2.5◦ on average (ASTM D883). HDPE: See high density polyethylene.

glycol-modified polycyclohexylenedimethylene terephthalate: Thermoplastic polyester prepared from glycol, cyclohexylenedimethanol, and terephthalic acid. Has good impact strength and other mechanical properties, chemical resistance, and clarity. Processed by injection molding and extrusion. Can be blended with polycarbonate. Also called PCTG. glycols: Aliphatic alcohols with two hydroxy groups attached to a carbon chain. Can be produced by the oxidation of alkenes followed by hydration. Also called dihydric alcohols, dihydroxy alcohols. gray scale rating: Evaluating light-induced changes in the color of materials such as plastics, rubbers, and nonmetallic coatings by comparing to a gray scale. A gray scale is a series of achromatic tones (usually ten) having varying proportions of white and black, to give a full range of grays between white and black.

H halogen compounds: A class of organic compounds containing halogen atoms such as chlorine. A simple example is halocarbons, but many other subclasses with various functional groups and of different molecular structure exist as well. halohydrins: Halogen compounds that contain a halogen atom(s) and a hydroxy (OH) group(s) attached to a carbon chain or ring. Can be prepared by the reaction of halogens with alkenes in the presence of water or by the reaction of halogens with triols. Halohydrins can be easily dehydrochlorinated in the presence of a base to give an epoxy compound. HALS: See hindered amine tight stabilizer.

HDT: See heat deflection temperature. heat deflection temperature.

point: See

heat

deflection

heat deflection temperature: The temperature at which a material specimen (standard bar) is deflected by a certain degree under a specified load. Also called heat distortion temperature, heat distortion point, heat deflection point, deflection temperature under load, tensile heat distortion temperature, HDT. heat distortion temperature.

point: See

heat

deflection

heat distortion temperature: See heat deflection temperature. heterocyclic compounds: A class of cyclic compounds containing rings with some carbon atoms replaced by other atoms such as oxygen, sulfur, and nitrogen. hiding power: The capacity of a coating material such as paint and, by extension, of the pigment in it to render invisible or cover up a surface on which it is applied as a film. For paints, hiding power is often expressed in gallons per square foot. Also called opacity. high density polyethylene: A linear polyethylene with density 0.94–0.97 g/cm3 . Has good toughness at low temperatures, chemical resistance, and dielectric properties and high softening temperature, but poor weatherability. Processed by extrusion, blow and injection molding, and powder coating. Used in houseware, containers, food packaging, liners, cable insulation, pipes, bottles, and toys. Also called HDPE.

421

Glossary of Terms

high impact polystyrene: See impact polystyrene. high molecular weight low density polyethylene: Thermoplastic with improved abrasion and stress crack resistance and impact strength, but poor processibility and reduced tensile strength. Also called HMWLDPE. hindered amine light stabilizer: Amines, such as piperidine derivatives, with a bulky, sterically hindered molecular structure. These light stabilizers photo-oxidize readily to nitroxyl radicals that neutralize, via recombination, alkyl radicals formed during the photodegradation of polymers such as polyolefins and therefore retard this process. Also called HALS. HIPS: See impact polystyrene. HMWLDPE: See high molecular weight law density polyethylene. HPUV: A test used to simulate the effect of fluorescent lighting and filtered sunlight. The HPUV test uses two lamps simultaneously, a cool white fluorescent lamp and a filtered sunlamp. hue: See color. Hunter color meter: See colorimeter. hydrophilic surface.

starch

surface: See

hydrophilic

hydrophilic surface: The surface of a hydrophilic substance that has a strong ability to bind, adsorb, or absorb water; a surface that is readily wettable with water. Hydrophilic substances include carbohydrates such as starch.Also called hydrophilic starch surface. hydroxy compounds: A broad class of organic compounds that contain a hydroxy (OH) group(s) that is not part of another functional groups such as carboxylic groups. Also called hydroxyl-containing compounds.

A solid at room temperature, insoluble in water but soluble in alcohols. Also called hydroxybenzophenone. hydroxyl-containing compounds: See hydroxy compounds. I ignition resistant chemical additives: See flame retardant. impact energy: The energy required to break a specimen, equal to the difference between the energy in the striking member of the impact apparatus at the instant of impact and the energy remaining after complete fracture of the specimen. Also called impact strength. See also ASTM D256, ASTM D3763. impact polystyrene: Impact polystyrene is a thermoplastic produced by polymerizing styrene dissolved in butadiene rubber. Impact polystyrene has good dimensional stability, high rigidity, and good low temperature impact strength, but poor barrier properties, grease resistance, and heat resistance. Processed by extrusion, injection molding, thermoforming, and structural foam molding. Used in food packaging, kitchen housewares, toys, small appliances personal care items, and audio products. Also called IPS, high impact polystyrene, HIPS, impact PS. impact property tests: Names and designations of the methods for the impact testing of materials. Also called impact tests. See also impact toughness. impact PS: See impact polystyrene. impact strength: The energy required to break a specimen, equal to the difference between the energy in the striking member of the impact apparatus at the instant of impact with the specimen and the energy remaining after complete fracture of the specimen. impact strength: See impact energy.

hydroxybenzophenone: See phenone.

2-hydroxybenzc-

hydroxybenzophenone(2-): An aromatic ketone, C6 H5 COC6 H4 OH, used as a UV absorber in plastics.

impact tests: See impact property tests. impact toughness: The property of a material indicating its ability to absorb energy of a high-speed

422

The Effects of UV Light and Weather on Plastics and Elastomers

impact by plastic deformation rather than crack or fracture. See also impact property tests. inoculum: A small amount of medium containing microorganisms from a pure culture which is used to start a new culture or to introduce microorganisms into a specimen. ionomers: Thermoplastics containing a relatively small amount of pendant ionized acid groups. Have good flexibility and impact strength in a wide temperature range, puncture and chemical resistance, adhesion, and dielectric properties, but poor weatherability, fire resistance, and thermal stability. Processed by injection, blow and rotational molding, blown film extrusion, and extrusion coating. Used in food packaging, auto bumpers, sporting goods, and foam sheets.

Blue Wool Standards. Other climatic conditions are recorded as well. The deterioration of the specimen is assessed visually and by measuring the change in color or other properties. ISO 4665 part 3: An international standard describing the methods of exposure to the artificial daylight from a xenon-arc lamp during accelerated light resistance testing of vulcanized rubber. The lamp is equipped with a filter to reduce short wavelength emission and is installed in an enclosure. The test is carried out at a black panel temperature about 55◦ C and relative humidity of about 65% without water spray or with intermittent water spray. The deterioration of the specimen is assessed visually and by measuring the change in color or other properties. Radiation dosage is determined by a photoreceptor, Blue Wool Standards (ISO 105-B01) and the gray scale (ISO 105-A02), or other physical standards.

IPS: See impact polystyrene.

ISO 105-B04: See DIN 54071.

ISO 4892: An international standard describing the methods of exposure to artificial light from a xenonarc, enclosed carbon-arc, or open-flame carbon-arc lamp during accelerated light resistance testing of plastics and textiles. The lamp is equipped with a filter to reduce short wavelength emission and is installed in an enclosure. The test is carried out at a black panel temperature about 45–63◦ C and relative humidity of about 35–90% without water spray or with intermittent water spray. The deterioration of the specimen is assessed visually and by measuring the change in color or other properties. Radiation dosage is determined by a photoreceptor. Blue Wool Standards (ISO 105-B01) and the gray scale (ISO 105-A02), or other physical standards. Also called ISO 4892/2 method A, ISO 4892/2 method B.

ISO 105-B06: See DIN 54003.

ISO 4892/2 method A: See ISO 4892.

ISO 877: See DIN 53388.

ISO 4892/2 method B: See ISO 4892.

ISO 4665 part 2: An international standard describing the methods of outdoor exposure of vulcanized rubber to assess its resistance to weathering and ozone cracking under atmospheric conditions with or without a glass cover. The specimens are mounted on a sloped rack facing the equator in direct sun, normally without backing, for up to 6 years. Strain is applied for the ozone cracking resistance test. Solar radiation is measured by a photoreceptor or by

isophthalate polyester: An unsaturated polyester based on isophthalic acid.

iron oxide: A dark red powder, Fe2 O3 , widely used, especially as a heat-stable, anticorrosive pigment in coatings. Produced synthetically or from iron ores. irradience: The amount of radiant power per unit area of irradiated surface at a point in time.Ameasure of radiation exposure, it is often expressed in the units of watt per square meter (W/m2 ). Also called radiant flux density. ISO 105-A02: See DIN 54001. ISO 105-B02: See DIN 54004.

Izod: See Izod impact energy. Izod impact: See Izod impact energy. Izod impact energy: The energy required to break a specimen, equal to the difference between the energy

423

Glossary of Terms

in the striking member of the Izod-type impact apparatus at the instant of impact and the energy remaining after complete fracture of the specimen. Also called Izod impact, Izod impact strength, Izod.

lightfastness: The resistance of a material to deterioration as evident by a change in color, performance, mechanical properties, etc., as a result of exposure to sunlight or a artificial light source. Also called light stability.

Izod impact strength: See Izod impact energy. J J: See joule. joule: A unit of energy in the SI system that is equal to the work done when the point of application of a force of one newton (N) is displaced through distance of one meter (m) in the direction of the force. The dimension of joule is N m. Also called J. K kinetic strip test: An ozone resistance test for rubbers that involves a strip-shaped specimen stretched to 23% and relaxed to 0 at a rate of 30 cycles per minute, while subjected to ozone attack in the test chamber. The results of the test are reported with two digits separated with a virgule. The number before the virgule indicates the number of quarters of the test strip which showed the cracks. The number after the virgule indicates the size of the cracks in length perpendicular to the length of the strip. L langley: A unit of total solar radiation that is equal to one calorie of heat energy per square centimeter of irradiated surface (1 gram calorie/cm2 /minute). LCP: See liquid crystal polymers. LDPE: See low density polyethylene. light cycle: In weathering and light exposure testing that simulates outdoor environments, a period when the specimen is irradiated, which alternates with the period of darkness.

linear low density polyethylene: Linear polyethylenes with density 0.91–0.94 g/cm3 . Has better tensile, tear, and impact strength and crack resistance properties, but poorer haze and gloss than branched low density polyethylene. Processed by extrusion at increased pressure and higher melt temperatures compared to branched low density polyethylene, and by molding. Used to manufacture films, sheets, pipes, electrical insulation, liners, bags, and food wraps. Also called LLDPE, LLDPE resin. linear polyethylenes: Linear polyethylenes are polyolefins with linear carbon chains. They are prepared by copolymerization of ethylene with small amounts of higher alfa-olefins such as 1-butene. Linear polyethylenes are stiff, tough, and have good resistance to environmental cracking and low temperatures. Processed by extrusion and molding. Used to manufacture films, bags, containers, liners, profiles, and pipes. liquid crystal polymers: Thermoplastic aromatic copolyesters with highly ordered structure. Have good tensile and flexural properties at high temperatures, chemical, radiation and fire resistance, and weatherability. Processed by sintering and injection molding. Used to substitute ceramics and metals in electrical components, electronics, chemical apparatus, and aerospace and auto parts. Also called LCP. lithopone red: A weather-resistant inorganic red pigment containing cadmium sulfoselenide, zinc sulfide, barium sulfate, and zinc oxide. Used in plastics.

light stability: See lightfastness.

lithopone yellow: A weather-resistant inorganic yellow pigment (Color Index Number 77199:1) containing cadmium sulfide, zinc sulfide, barium sulfate, and zinc oxide. Used in plastics. Also called C.I. Pigment Yellow 37:1.

light transmission: See transmittance.

LLDPE: See linear low density polyethylene.

424

The Effects of UV Light and Weather on Plastics and Elastomers

LLDPE resin: See linear low density polyethylene. low density polyethylene: A branched-chain thermoplastic with density 0.91–0.94 g/cm3 . Has good impact strength, flexibility, transparency, chemical resistance, dielectric properties, and low water permeability and brittleness temperature, but poor heat, stress cracking and fire resistance and weatherability. Processed by extrusion coating, injection and blow molding, and film extrusion. Can be cross-linked. Used in packaging and shrink films, toys, bottle caps, cable insulation, and coatings. Also called LDPE. luminous transmittance: See transmittance.

M macroscopic properties.

properties: See

thermodynamic

magnesia: See magnesium oxide. magnesium oxide: A while powder, MgO, produced by calcining magnesium carbonate or hydroxide in several grades (technical, fused, rubber, etc.). Used as filler, thickening agent in polyesters, and inorganic rubber accelerator. Also called magnesia. masking filler: A filler or pigment with low hiding power added in small amounts to clear plastics to mask their natural tint (e.g., blue pigments are added to mask the yellow tine). Also called color masking agent. masstone green vulcanizates: Vulcanized rubber containing no other pigments but a green one. matte surface: A dull or low-gloss surface that is more prone to light scattering than reflection. MBT: See 2-mercaptobenzothiazole. mechanical properties: Properties describing the reaction of physical systems to stress and strain. melamine resins: Thermosetting resins prepared by the condensation of formaldehyde with melamine.

Have good hardness, scratch and fire resistance, clarity, colorability, rigidity, dielectric properties, and tensile strength, but poor impact strength. Molding grades are filled. Processed by compression, transfer, and injection molding, impregnation, and coating. Used in cosmetic containers, appliances, tableware, electrical insulators, furniture laminates, adhesives, and coatings. mercaptobenzothiazole(2-): A nitrogen- and sulfur-containing polyheterocyclic organic thiol used as vulcanization accelerator for rubber. Requires zinc oxide as an activator. Its vulcanizates have a good aging resistance. A yellowish powder with distinctive odor. Combustible. Also called MBT. mercury cadmium red: An inorganic red pigment containing mercury and cadmium sulfides; used mainly in rubber; has good light and heat resistance. methylfluorosilicones: Silicone rubbers containing pendant fluorine and methyl groups. Have good chemical and heat resistance. Used in gasoline lines, gaskets, and seals. Also called FMQ. methylphenylsilicones: Silicone rubbers containing pendant phenyl and methyl groups. Have good resistance to heat, oxidation, and radiation, and compatibility with plastics. methylsilicone: Silicone rubbers containing pendant methyl groups. Have good heat and oxidation resistance. Used in electrical insulations and coatings. Also called MQ. methylvinylfluorosilicone: Silicone rubbers containing pendant vinyl, methyl, and fluorine groups. Can be additionally cross-linked via vinyl groups. Have good resistance to petroleum products at elevated temperatures. methylvinylsilicone: Silicone rubbers containing pendant methyl and vinyl groups. Can be additionally cross-linked via vinyl groups. Vulcanized to high degrees of cross-linking. Used in sealants, adhesives, coatings, cables, gaskets, tubing, and electrical tape. microbiological attack: See biodegradation.

425

Glossary of Terms micrometer: A unit of length equal to 1 × 10−6 meter. Its symbol is the Greek small letter µ or µm. microtensile specimen: A small specimen as specified in ASTM D1708 for determining tensile properties of plastics. It has a maximum thickness 3.2 mm and a minimum of length 38.1 mm. Tensile properties determined with this specimen include yield strength, tensile strength, tensile strength at break, and elongation at break. migration: A moss-transfer process in which the matter moves from one place to another usually in a slow and spontaneous fashion. In plastics and coatings, migration of pigments, fillers, plasticizers, and other ingredients via diffusion or floating to the surface or through interface to other materials results in various defects called blooming, chalking, bronzing, flooding, bleeding, etc. mildew resistance: The ability of a material such as plastics or nonmetallic coatings to resist fungus growth and deterioration caused by fungi such as common mold, including polymer degradation and discoloration. Also called fungus resistance. mineral salt medium: A corrosive medium such as an aqueous solution, containing mineral or inorganic salts such as sodium chloride (NaCl). Used in material testing, especially of anticorrosive properties.

using wrong tooling, process parameters, ingredients, etc. Also called molding flaw. See also design, etc. Usually preventable. molding flaw: See molding defects. molecular weight: The sum of the atomic weights of all atoms in a molecule. Also called MW. molecular weight distribution: The relative amounts of polymeric molecules of different weights in a specimen. Note: The molecular weight distribution can be expressed in terms of the ratio between weight- and number-average molecular weights. Also called polydispersity, MWD, molecular weight ratio. molecular weight ratio: See molecular weight distribution. Monastral Blue: A blue copper phthalocyanine pigment with excellent light stability and high stability to vulcanization and aging; non-bleeding. Used in paints, rubbers, plastics such as PVC, and textiles such as rayon. Since it has a low hiding power small amounts of it (2–10 ppm) are added to clear plastics to neutralize slightly yellow tint. MPE: See modified polyphenylene ether. MPO: See modified polyphenylene ether.

modified polyphenylene ether: Thermoplastic polyphenylene ether alloys with impact polystyrene. Have good impact strength and resistance to heat and fire, but poor resistance to solvents. Processed by injection and structural foam molding and extrusion. Used in auto parts, appliances, and telecommunication devices. Also called MPE, MPO, modified polyphenylene oxide.

MQ: See methylsilicone. mulch film: A film, usually dark-colored PVC film, used instead of mulch in agriculture (e.g., to prevent fruit rotting and runners and weed growth in cultivation of strawberries). MW: See molecular weight.

modified polyphenylene oxide: See modified polyphenylene ether.

MWD: See molecular weight distribution.

modulus of rupture: See flexural strength. N modulus of rupture in bending: See flexural strength. molding defects: Structural and other defects in material caused inadvertently during molding by

nanometer: Aunit of length equal to 1×10−9 meter. Often used to denote the wavelength of radiation, especially in the UV and visible spectral region. Also called nm.

426

The Effects of UV Light and Weather on Plastics and Elastomers

neoprene rubber: Polychloroprene rubbers with good resistance to petroleum products, heat and ozone, weatherability, and toughness. nickel complex light stabilizer: Light stabilizers for plastics comprising nickel complexes such as nickel acetylacetonate, dithiolate, or pyridylbenzimidazole complexes. Their stabilization mechanism differs but most act as UV absorbers. nitrile rubber: Rubbers prepared by free-radical polymerization of acrylonitrile with butadiene. Have good resistance to petroleum products, heat, and abrasion. Used in fuel hoses, shoe soles, gaskets, oil seals, and adhesives. nitroarylamine: A class of aromatic amines containing benzene ring(s) with nitro (NO2 group substituent(s), such as nitroaniline (O2 NC6 H4 NH2 ). Used as organic intermediates (e.g., in dye synthesis) and antioxidants in propellants and plastics. nm: See nanometer. nonelastomeric thermoplastic polyurethanes: See rigid thermoplastic polyurethanes. nonelastomeric thermosetting polyurethane: Curable mixtures of isocyanate prepolymers or monomers. Have good abrasion resistance and lowtemperature stability, but poor heat, fire, and solvent resistance and weatherability. Processed by reaction injection and structural foam molding, casting, potting, encapsulation, and coating. Used in heat insulation, auto panels and trim, and housings for electronic devices. notch effect: The effect of the presence of a specimen notch or its geometry on the outcome of a test such as an impact strength test of plastics. Notching results in local stresses and accelerates failure in both static and cycling testing (mechanical, ozone cracking, etc.).

between the energy in the striking member of the Izod-type impact apparatus at the instant of impact and the energy remaining after complete fracture of the specimen. Note: Energy depends on geometry (e.g., width, depth, shape) of the notch, on the crosssectional area of the specimen, and on the place of impact (on the side of the notch or on the opposite side). In some tests a notch is made on both sides of the specimen. Also called notched Izod impact strength, notched Izod impact, notched Izod. notched Izod impact strength: See notched Izod impact energy. nylon: Thermoplastic polyamides often prepared by ring-opening polymerization of lactam. Have good resistance to most chemicals, abrasion, and creep, good impact and tensile strengths, barrier properties, and low friction, but poor resistance to moisture and light. Have high mold shrinkage. Processed by injection, blow, and rotational molding, extrusion, and powder coating. Used in fibers, auto parts, electrical devices, gears, pumps, appliance housings, cable jacketing, pipes, and films. nylon 6: Thermoplastic polymer of caprolactam. Has good weldability and mechanical properties but rapidly picks up moisture which results in strength losses. Processed by injection, blow, and rotational molding and extrusion. Used in fibers, tire cord, and machine parts. nylon 11: Thermoplastic polymer of 11-aminoundecanoic acid. Has good impact strength, hardness, abrasion resistance, processability, and dimensional stability. Processed by powder coating, rotational molding, extrusion, and injection molding. Used in electric insulation, tubing, profiles, bearings, and coatings.

notched Izod impact: See notched Izod impact energy.

nylon 12: Thermoplastic polymer of lauric lactam. Has good impact strength, hardness, abrasion resistance, and dimensional stability. Processed by powder coating, rotational molding, extrusion, and injection molding. Used in sporting goods and auto parts.

notched Izod impact energy: The energy required to break a notched specimen, equal to the difference

nylon 46: Thermoplastic 2-pyrrolidone and caprolactam.

notched Izod: See notched Izod impact energy.

copolymer

of

427

Glossary of Terms

nylon 66: Thermoplastic polymer of adipic acid and hexamethylenediamine. Has good tensile strength, elasticity, toughness, heat resistance, abrasion resistance, and solvent resistance, but low weatherability and color resistance. Processed by injection molding and extrusion. Used in fibers, bearings, gears, rollers, and wire jackets. nylon 610: Thermoplastic polymer of hexamethylenediamine and sebacic acid. Has decreased melting point and water absorption and good retention of mechanical properties. Processed by injection molding and extrusion. Used in fibers and machine parts. nylon 612: Thermoplastic polymer of 1,12dodecanedioic acid and hexamethylenediamine. Has good dimensional stability, low moisture absorption, and good retention of mechanical properties. Processed by injection molding and extrusion. Used in wire jackets, cable sheath, packaging film, fibers, bushings, and housings. nylon 666: Thermoplastic polymer of adipic acid, caprolactam, and hexamethylenediamine. Has good strength, toughness, abrasion and fatigue resistance, and low friction, but high moisture absorption and low dimensional stability. Processed by injection molding and extrusion. Used in electrical devices and auto and mechanical parts. nylon MXD6: Thermoplastic polymer of mxylyleneadipamide. Has good flexural strength and chemical resistance, but decreased tensile strength.

opacity: See hiding power. optical characteristics: See optical properties. optical properties: The effects of a material or medium on light or other electromagnetic radiation passing through it, such as absorption, reflection, etc. Also called optical characteristics. optical transmittance: See transmittance. organic compounds: Chemical compounds based on carbon chains and rings and also containing hydrogen that can be entirely or partially substituted with oxygen, nitrogen and other elements, Also called organic substances. organic compounds: See halogen compounds. organic substances: See organic compounds. outgassing rate: See degassing rate. oxazolines: Heterocyclic compounds containing five-membered rings in which one carbon is replaced with an oxygen atom and another with a nitrogen atom. Oxazolines are colorless liquids soluble in organic solvents and water. Used as intermediates in the synthesis of surfactants. ozone: An allotropic form of oxygen, O3 . Unstable gas formed naturally in air by lightning or in the stratosphere by the UV portion of solar radiation, or formed as a result of combustion of fossil fuels (i.e., in exhaust gases from automobiles). O3 is an active oxidizing agent that accelerates deterioration of rubber.

O P olefin resins: See polyolefins. PA: See polyamides. olefinic resins: See polyolefins. PABM: See polyaminobismaleimide resins. olefinic thermoplastic elastomers: Blends of EPDM or EP rubbers with polypropylene or polyethylene, optionally cross-linked. Have low density, good dielectric and mechanical properties, and processibility, but low oil resistance and high flammability. Processed by extrusion, injection and blow molding, thermoforming, and calendering. Used in auto parts, construction, wire jackets, and sporting goods. Also called TPO.

paraffinic plasticizer: Plasticizers for plastics comprising liquid or solid long-chain alkanes or paraffins (saturated linear or branched hydrocarbons). parts per hundred: A relative unit of concentration, parts of one substance per 100 parts of another. Parts can be measured by weight, volume, count, or any other suitable unit of measure. Used often to

428

The Effects of UV Light and Weather on Plastics and Elastomers

denote the composition of a blend or mixture, such as plastics, in terms of the parts of a minor ingredient, such as plasticizer, per 100 parts of a major, such as resin. Also called phr. parts per hundred million: A relative unit of concentration, parts of one substance per 100 million parts of another. Parts can be measured by weight, volume, count, or any other suitable unit of measure. Used often to denote a very small concentration of a substance, such as an impurity or a toxin, in a medium, such as air. Also called pphm.

percentage light transmittance: See transmittance. perfluoroalkoxy resins: Thermoplastic polymers of perfluoroalkoxyethylenes. Has good creep, heat, and chemical resistance and processibility, but low compressive and tensile strengths. Processed by molding, extrusion, rotational molding, and powder coating. Used in films, coatings, pipes, containers, and chemical apparatus linings. Also called PFA. PES: See polyethersulfone.

PBI: See polybenzimidazoles.

PET: See polyethylene terephthalate.

PBT: See polybutylene terephthalate.

PETG: See polycyclohexylenedimethylene ethylene terephthalate.

PC: See polycarbonates. PFA: See perfluoroalkoxy resins. PCT: See polycyclohexylenedimethylene terephthalate. PCTG: See glycol-modified polycyclohexylenedimethylene terephthalate. PE copolymer: See polyethylene copolymer.

phase transition: See phase transition properties. phase transition point: The temperature at which a phase transition occurs in a physical system such as a material. Note: An example of phase transition is glass transition. Also called phase transition temperature, transition point, transition temperature.

PEEK: See polyetheretherketone. PEI: See polyetherimides. PEK: See polyetherketone. pendant aromatic rings: Aromatic (conjugated unsaturated rings such as those of benzene, C6 H6 ) rings attached to the main chain of a polymer molecule. Penicillium funiculosum: A species of common mold belonging to the genus Penicillium. Used alone or in artificial mixtures with other fungi to prepare cultures for the testing of mildew resistance of materials such as plastics, or fungicidal activity of antimildew agents or fungicides. pentaerythritol: A polyol, C(CH2 OH)4 , prepared by the reaction of acetaldehyde with excess formaldehyde in an alkaline medium. Used as a plasticizer and as a monomer in alkyd resins.

phase transition properties: Properties of physical systems such as materials associated with their transition from one phase to another (e.g., from liquid to solid phase). Also called phase transition. phase transition temperature: See phase transition point. phenolic resins: Thermoset polymers of phenols with excess or deficiency of aldehydes, mainly formaldehyde, to give resole or novolak resins, respectively. Heat-cured resins have good dielectric properties, hardness, thermal stability, rigidity, and compressive strength but poor chemical resistance and dark color. Processed by coating, potting, compression, transfer, or injection molding and extrusion. Used in coatings, adhesives, potting compounds, handles, electrical devices, and auto parts. photo bleaching: See photochemical bleaching.

429

Glossary of Terms

photo-Fries rearrangement: See photochemical Fries rearrangement. photochemical bleaching: Complete loss of color of the material as a result of photodegradation of colored substances present in its surface layer. Also called photobleaching.

or low-melting point solids such as dioctyl phthalate or stearic acid. They have to be nonbleeding, nontoxic, and compatible with the material. Sometimes plasticizers play a dual role as stabilizers or cross-linkers. plastics: See polymers.

photochemical degradation: Degradation as a result of light-induced reactions such as photolysis. Also called photodegradation.

PMMA: See polymethyl methacrylate.

photochemical Fries rearrangement: Rearrangement of phenolic esters to o- and/or p-phenolic ketones induced by light. Also called photo-Fries rearrangement.

polyacrylates: See acrylic resins.

photodegradation: See dation.

photochemical

degra-

photo-oxidation: Oxidation of a substance such as polymer, initiated by light, especially the UV portion of it.An important part of polymer photodegradation. Usually proceeds via formation of peroxides, which readily decompose to highly reactive free radicals. Inhibited or retarded in polymers by antioxidants and light stabilizers. phr: See parts per hundred. phthalocyanine: Anitrogen-containing heterocyclic organic compound, (C6 H4 C2 N)2 (C6 H4 C2 NH)2 N4 , belonging to the group of benzoporphyrins and comprising four isoindole groups jointed by four nitrogen atoms. Readily forms salt complexes with copper, chromium, iron, etc., that are important green and blue dyes and pigments. These pigments have high light and chemical stability. Used in coatings, plastics, and textiles. PI: See polyimides. plasticizer: A substance incorporated into a material such as a plastic or rubber to increase its softness, processability, and flexibility via solvent or lubricating action or by lowering its molecular weight. Plasticizers can lower melt viscosity, improve flow, and increase low-temperature resilience of the material. Most plasticizers are nonvolatile organic liquids

PMP: See polymethylpentene.

polyallomer: Crystalline thermoplastic block copolymers of ethylene, propylene, and other olefins. Have good impact strength and flex life and low density. polyamide thermoplastic elastomers: Copolymers containing soft polyether and hard polyamide blocks having good chemical, abrasion, and heat resistance, impact strength, and tensile properties. Processed by extrusion and injection and blow molding. Used in sporting goods, auto parts, and electrical devices. Also called polyamide TPE. polyamide TPE: See polyamide thermoplastic elastomers. polyamides: Thermoplastic aromatic or aliphatic polymers of dicarboxylic acids and diamines, of amino acids, or of lactams. Have good mechanical properties, chemical resistance, and antifriction properties. Processed by extrusion and molding. Used in fibers and molded parts. Also called PA. polyaminobismaleimide resins: Thermoset polymers of aromatic diamines and bismaleimides having good flow and thermochemical properties and flame and radiation resistance. Processed by casting and compression molding. Used in aircraft parts and electrical devices. Also called PABM. polyarylamides: Thermoplastic crystalline polymers of aromatic diamines and aromatic dicarboxylic anhydrides. Have good heat, fire, and chemical resistance, property retention at high temperatures, dielectric and mechanical properties, and stiffness,

430

The Effects of UV Light and Weather on Plastics and Elastomers

but poor light resistance and processibility. Processed by solution casting, molding, and extrusion. Used in films, fibers, and molded parts. polyarylsulfone: Thermoplastic aromatic polyetherpolysulfone having good heat, fire, and chemical resistance, impact strength, resistance to environmental stress cracking, dielectric properties, and rigidity. Processed by injection and compression molding and extrusion. Used in circuit boards, lamp housings, piping, and auto parts. polybenzimidazoles: Mainly polymers of 3,3 ,4 tetraminonbiphenyl(diaminobenzidine) and diphenyl isophthalate. Have good heat, fire, and chemical resistance. Used as coatings and fibers in aerospace and other high-temperature applications. Also called FBI. polybutylene terephthalate: Thermoplastic polymer of dimethyl terephthalate and butanediol. Has good tensile strength, dielectric properties, and chemical and water resistance, but poor impact strength and heat resistance. Processed by injection and blow molding, extrusion, and thermoforming. Used in auto body parts, electrical devices, appliances, and housings. Also called PBT. polycarbodiimide: Polymers containing –N= C=N– linkages in the main chain, typically formed by catalyzed polycondensation of polyisocyanates. They are used to prepare open-celled foams with superior thermal stability. Sterically hindered polycarbodiimides are used as hydrolytic stabilizers for polyester-based urethane elastomers. polycarbonate: See polycarbonates. polycarbonate-polyester alloys: High-performance thermoplastics processed by injection and blow molding. Used in auto parts.

can be aliphatic or aromatic. They have very good mechanical properties, especially impact strength, low moisture absorption, and good thermal and oxidative stability. They are self-extinguishing and some grades are transparent. Polycarbonates have relatively low chemical resistance and resistance to stress cracking. Processed by injection and blow molding, extrusion, thermoforming at relatively high processing temperatures. Used in telephone parts, dentures, business machine housings, safety equipment, nonstaining dinnerware, food packaging, etc. Also called polycarbonate, PC, polycarbonate resins. polychlorotrifluoroethylene: Thermoplastic polymer of chlorotrifluoroethylene. Has good transparency, barrier properties, tensile strength, and creep resistance, modest dielectric properties and solvent resistance, and poor processibility. Processed by extrusion, injection and compression molding, and coating. Used in chemical apparatus, lowtemperature seals, films, and internal lubricants. Also called CTFE. polycyclohexylenedimethylene ethylene terephthalate: Thermoplastic polymer of cyclohexylenedimethylenediol, ethylene glycol, and terephthalic acid. Has good clarity, stiffness, hardness, and lowtemperature toughness. Processed by injection and blow molding and extrusion. Used in containers for cosmetics and foods, packaging film, medical devices, machine guards, and toys. Also called PETG. polycyclohexylenedimethylene terephthalate: Thermoplastic polymer of cyclohexylenedimethylenediol and terephthalic acid. Has good heat resistance. Processed by molding and extrusion.Also called PCT. polydispersity: See molecular weight distribution. polyester resins: See polyesters.

polycarbonate resins: See polycarbonates. polycarbonates: Polycarbonates are thermoplastics prepared by either phosgenation of dihydric aromatic alcohols such as bisphenol A or by transesterification of these alcohols with carbonates (e.g., diphenyl carbonate). Polycarbonates consist of chains with repeating carbonyldioxy groups and

polyester thermoplastic elastomers: Copolymers containing soft polyether and hard polyester blocks having good dielectric strength, chemical and creep resistance, dynamic performance, appearance, and retention of properties in a wide temperature range, but poor light resistance. Processed by injection, blow, and rotational molding, extrusion casting, and

431

Glossary of Terms

film blowing. Used in electrical insulation, medical products, auto parts, and business equipment. Also called polyester TPE. polyester TPE: See elastomers.

polyester

thermoplastic

polyesters: A broad class of polymers usually made by the condensation of a diol with dicarboxylic acid or anhydride. Polyesters consist of chains with repeating carbonyloxy group and can be aliphatic or aromatic. There are thermosetting polyesters such us alkyd resins and unsaturated polyesters and thermoplastic polyesters such as PET. The properties, processing methods, and applications of polyesters vary widely. Also called polyester resins. polyetheretherketone: Semi-crystalline thermoplastic aromatic polymer. Has good chemical, heat, fire, and radiation resistance, toughness, rigidity, bearing strength, and processibility. Processed by injection molding, spinning, cold forming, and extrusion. Used in fibers, films, auto engine parts, aerospace composites, and electrical insulation. Also called PEEK. polyetherimides: Thermoplastic cyclized polymers of aromatic diether dianhydrides and aromatic diamines. Have good chemical, creep, and heat resistance and dielectric properties. Processed by extrusion, thermoforming, and compression, injection, and blow molding. Used in auto parts, jet engines, surgical instruments, industrial apparatus, food packaging, cookware, and computer disks. Also called PEI. polyetherketone: Thermoplastic having good heat and chemical resistance and thermal stability. Used in advanced composites, wire coating, filters, integrated circuit boards, and bearings. Also called PEK. polyethersulfone: Thermoplastic aromatic polymers having good heat and fire resistance, transparency, dielectric properties, dimensional stability, rigidity, and toughness, but poor solvent and stress cracking resistance, processibility, and weatherability. Processed by injection, blow, and compression molding and extrusion. Used in high-temperature applications, electrical devices, medical devices,

housings, and aircraft and auto parts. Also called PES. polyethylene copolymer: Thermoplastic polymers of ethylene with other olefins such as propylene. Processed by molding and extrusion. Also called PE copolymer. polyethylene terephthalate: Thermoplastic polymer of ethylene glycol with terephthalic acid. Has good hardness, wear and chemical resistance, dimensional stability, and dielectric properties. Highcrystallinity grades have good tensile strength and heat resistance. Processed by extrusion and injection and blow molding. Used in fibers, food packaging (films, bottles, trays), magnetic tapes, and photo films. Also called PET. polyimides: Thermoplastic aromatic cyclized polymers of trimellitic anhydride and aromatic diamine. Have good tensile strength, dimensional stability, dielectric and barrier properties, and creep, impact, heat, and fire resistance, but poor processibility. Processed by compression and injection molding, powder sintering, film casting, and solution coating. Thermoset uncyclized polymers are heat curable and have good processability. Processed by transfer and injection molding, lamination, and coating. Used in jet engines, compressors, sealing coatings, auto parts, and business machines. Also called PI. polymer chain unsaturation.

unsaturation: See

chemical

polymers: Polymers are high-molecular weight organic or inorganic compounds the molecules of which comprise linear, branched, cross-linked, or otherwise shaped chains of repeating molecular groups. Synthetic polymers are prepared by polymerization of one or more monomers. The monomers are low-molecular weight substances with one or more reactive bonds or functional groups.Also called resins, plastics. polymethyl methacrylate: Thermoplastic polymer of methyl methacrylate having good transparency, weatherability, impact strength, and dielectric properties. Processed by compression and injection molding, casting, and extrusion. Used in lenses, sheets,

432

The Effects of UV Light and Weather on Plastics and Elastomers

airplane canopies, signs, and lighting fixtures. Also called PMMA. polymethylpentene: Thermoplastic polymer of 4-methyl-1-pentene having low density, good transparency, rigidity, dielectric and tensile properties, and heat and chemical resistance. Processed by injection and blow molding and extrusion. Used in laboratory ware, coated paper, light fixtures, auto parts, and electrical insulation. Also called PMP. polyolefin resins: See polyolefins. polyolefins: Polyolefins are a broad class of hydrocarbon-chain elastomers or thermoplastics usually prepared by the addition (co)polymerization of alkenes such as ethylene. There are branched and linear polyolefins and some are chemically or physically modified. Unmodified polyolefins have relatively low thermal stability and a nonporous, nonpolar surface with poor adhesive properties. Processed by extrusion and injection, blow, and rotational molding. Polyolefins are used more and have more applications than any other polymers. Also called olefinic resins, olefin resins, polyolefin resins. polyphenylene ether nylon alloys: Thermoplastics having improved heat and chemical resistance and toughness. Processed by molding and extrusion. Used in auto body parts.

retention of properties at high temperatures, dielectric properties, and stiffness, but decreased light resistance and poor processibility. Processed by solution casting, molding, and extrusion. Used in films, fibers, and molded parts. Also called PPA. polypropylene: Thermoplastic polymer of propylene having low density and good flexibility and resistance to chemicals, abrasion, moisture, and stress cracking, but decreased dimensional stability, mechanical strength, and light, fire, and heat resistance. Processed by injection molding, spinning, and extrusion. Used in fibers and films for adhesive tapes and packaging. Also called PP. polystyrene: Polystyrenes are thermoplastics produced by polymerization of styrene with or without modification (e.g., by copolymerization or blending) to make impact resistant or expandable grades. They have good rigidity, high dimensional stability, low moisture absorption, optical clarity, high gloss, and good dielectric properties. Unmodified polystyrenes have poor impact strength and resistance to solvents, heat, and UV radiation. Processed by injection molding, extrusion, compression molding, and foam molding. Used widely in medical devices, house wares, food packaging, electronics, and foam insulation. Also called polystyrenes, PS, polystyrol. polystyrenes: See polystyrene.

polyphenylene sulfide: High-performance engineering thermoplastic having good chemical, water, fire, and radiation resistance, dimensional stability, and dielectric properties, but decreased impact strength and poor processibility. Processed by injection, compression, and transfer molding and extrusion. Used in hydraulic components, bearings, electronic parts, appliances, and auto parts. Also called PPS. polyphenylene sulfide sulfone: Thermoplastic having good heal, fire, creep, and chemical resistance and dielectric properties. Processed by injection molding. Used in electrical devices. Also called PPSS. polyphthalamide: Thermoplastic polymer of aromatic diamine and phthalic anhydride. Has good heat, chemical, and fire resistance, impact strength,

polystyrol: See polystyrene. polysulfones: Thermoplastics, often aromatic and with ether linkages, having good heat, fire, and creep resistance, dielectric properties, transparency, but poor weatherability, processibility, and stress cracking resistance. Processed by injection, compression, and blow molding and extrusion. Used in appliances, electronic devices, auto parts, and electric insulators. Also called PSO. polytetrafluoroethylene: Thermoplastic polymer of tetrafluoroethylene having good dielectric properties, chemical, heat, abrasion, and fire resistance, antiadhesive properties, impact strength, and weatherability, but decreased strength, processibility, barrier properties, and creep resistance. Processed by sinter molding and powder codling.

433

Glossary of Terms

Used in nonstick coatings, chemical apparatus, electrical devices, bearings, and containers. Also called PTFE.

abrasion and chemical resistance and barrier properties. Processed by molding and extrusion. Used in food packaging films, bag liners, pipes, upholstery, fibers, and coatings. Also called PVDC.

polyurethane resins: See polyurethanes. polyurethanes: Polyurethanes (Pus) are a broad class of polymers consisting of chains with a repeating urethane group, prepared by the condensation of polyisocyanates with polyols (e.g., polyester or polyether diols). PUs may be thermoplastic or thermosetting, elastomeric or rigid, cellular or solid, and offer a wide range of properties depending on their composition and molecular structure. Many PUs have high abrasion resistance, good retention of properties at low temperatures, and good foamability. Some have poor heat resistance, weatherability, and resistance to solvents. PUs are flammable and can release toxic substances. Thermoplastic PUs are not cross-linked and are processed by injection molding and extrusion. Thermosetting PUs can be cured at relatively low temperatures and give foams with good heat insulating properties. They are processed by reaction injection molding, rigid and flexible foam methods, casting, and coating. PUs are used in load bearing rollers and wheels, acoustic clamping materials, sporting goods, seals and gaskets, heat insulation, potting, and encapsulation. Also called PUR, PU, urethane polymers, urethane resins, urethanes, polyurethane resins. polyvinyl chloride: Thermoplastic polymer of vinyl chloride, available in rigid and flexible forms. Has good dimensional stability, fire resistance, and weatherability, but decreased heat and solvent resistance and high density. Processed by injection and blow molding, calendering, extrusion, and powder coating. Used in films, fabric coatings, wire insulation, toys, bottles, and pipes. Also called PVC.

polyvinylidene fluoride: Thermoplastic polymer of vinylidene fluoride having good strength, processibility, wear, fire, solvent, and creep resistance, and weatherability, but decreased dielectric properties and heat resistance. Processed by extrusion, injection, and transfer molding and powder coating. Used in electrical insulation, pipes, chemical apparatus, coatings, films, containers, and fibers. Also called PVDF. PP: See polypropylene. PPA: See polyphthalamide. pphm: See parts per hundred million. ppm: A unit for measuring small concentrations of a material or substance as the number of its parts (arbitrary quantity) per million parts of medium consisting of another material or substance. PPS: See polyphenylene sulfide. PPSS: See polyphenylene sulfide sulfone. prevulcanization: See scorching. process characteristics: See processing parameters. process conditions: See processing parameters. process media: See processing agents. process parameters: See processing parameters. process pressure: See processing pressure.

polyvinyl fluoride: Crystalline thermoplastic polymer of vinyl fluoride having good toughness, flexibility, weatherability, and low temperature and abrasion resistance. Processed by film techniques. Used in packaging, glazing, and electrical devices. Also called PVF.

process rate: See processing rate. process speed: See processing rate. process time: See processing time. process velocity: See processing rate.

polyvinylidene chloride: Stereoregular thermoplastic polymer of vinylidene chloride having good

processing additives: See processing agents.

434

The Effects of UV Light and Weather on Plastics and Elastomers

processing agents: Agents or media used in the manufacture, preparation, and treatment of a material or article to improve its processing or properties. The agents often become a part of the material. Also called process media, processing aids, processing additives.

promoter: Sec accelerator. PS: See polystyrene. PSO: See polysulfones. PTFE: See polytetrafluoroethylene.

processing aids: See processing agents. PU: See polyurethanes. processing defects: Structural and other defects in a material or article caused inadvertently during manufacturing, preparation, and treatment processes by using wrong tooling, process parameters, ingredients, part design, etc. Usually preventable. Also called processing flaw, defects, flaw. See also cracking.

PUR: See polyurethanes. PVC: See polyvinyl chloride. PVDC: See polyvinylidene chloride. PVDF: See polyvinylidene fluoride.

processing flaw: See, processing defects. PVF: See polyvinyl fluoride. processing methods: Method names and designations for material article manufacturing, preparation, and treatment processes. Note: Both common and standardized names are used. Also called processing procedures. processing parameters: Measurable parameters such as temperature prescribed or maintained during material or article manufacture, preparation, and treatment processes. Also called process characteristics, process conditions, process parameters. processing pressure: Pressure maintained in an apparatus during material or article manufacture, preparation, and treatment processes. Also called process pressure. See also pressure. processing procedures: See processing methods. processing rate: Speed of the process in manufacture, preparation, and treatment of a material or article. It usually denotes the change in a process parameter per unit of time or the throughput speed of material in a unit of weight, volume, etc., per unit of time. Also called process speed, process velocity, process rate. processing time: Time required for the completion of a process in the manufacture, preparation, and treatment of a material or article. Also called process time, cycle time.

Q QUV accelerated weathering tester: See fluorescent UV lamp-condensation apparatus. QFS-40 lamp: A fluorescent UV-B lamp with peak emission at 313 nm that provides high UV radiation output for accelerated indoor lightfastness and weatherability testing of materials such as plastics, nonmetallic coatings, and textiles. The lamp does not match closely the sunlight spectrum in the short wavelength region. Also called FS-40 (UV-B) lamps, FS-40, F40 UVB, F40-UVB, FS-401 lamp. quartz inner filter: An inner filter made from quartz glass in a xenon-arc lamp that in combination with a soda-lime or borosilicate glass outer filter selectively screens radiation output, especially in the short UV wavelength region, to simulate window glass-filtered daylight or sunlight, respectively, in an accelerated light exposure testing apparatus. quinacridone red: Alight-fast, chemically resistant organic red pigment used in paints, inks, and plastics. Properties of quinacridone pigments are similar to those of phthalocyanine pigments. QUV: See fluorescent UV lamp-condensation apparatus.

435

Glossary of Terms R

the mean line, respectively, divided by the length of this line. And called Ra.

Ra: See roughness average. rutile TiO2 : See rutile titanium oxide. radiant flux density: See irradience. reaction injection molding system: Liquid compositions, mostly polyurethane-based, of thermosetting resins, prepolymers, monomers, or their mixtures. Have good processibility, dimensional stability, and flexibility. Processed by foam molding with in-mold curing at high temperatures. Used in auto parts and office furniture, Also called RIM.

rutile titanium oxide: One of the naturally occurring crystal forms of titanium dioxide. Used as a white or opacifying pigment in a wide range of materials including coatings and plastics. Rutile titanium dioxide has a higher refractive index and opacity than anatase titanium dioxide, another crystal form of this oxide. The pigment is nonmigrating, heat resistant, chemically inert, and lightfast. Also called rutile TiO2 .

relative humidity: The ratio of the actual vapor pressure of the air to the saturation vapor pressure. Also called RH.

S

relative viscosity: The ratio of solution viscosity to the viscosity of the solvent. resins: See polymers. resorcinol-modified phenolic resins: Thermosetting polymers of phenol, formaldehyde, and resorcinol having good heat and creep resistance and dimensional stability. RH: See relative humidity. rigid thermoplastic polyurethanes: Right thermoplastic polyurethanes are not chemically crosslinked. They have high abrasion resistance, good retention of properties at low temperatures, but poor heat resistance, weatherability, and resistance to solvents. Rigid thermoplastic polyurethanes are flammable and can release toxic substances. Processed by injection molding and extrusion. Also called rigid thermoplastic urethanes, nonelastomeric thermoplastic polyurethanes. rigid thermoplastic urethanes: See rigid thermoplastic polyurethanes. Rim: See reaction injection molding system. roughness average: A height parameter of surface roughness equal to the average absolute deviation of surface profile from the mean line, calculated as the integrated area of peaks and valleys above and below

SAE J576: A Society of Automotive Engineers recommended practice for evaluating the suitability of plastics intended for molded optical parts such as lenses and reflectors of motor vehicle lighting devices. The suitability is determined by the extent of change of optical properties after outdoor conventional weathering (Arizona, Florida). The properties determined after exposure are luminous transmittance, chromaticity coordinates, haze, and appearance. SAE J1545: A Society of Automotive Engineers recommended practice for instrumented color difference measurement against reference standards for exterior finishes such as topcoat paints, interior textiles, and colored exterior and interior hard trims used in motor vehicles. The color is measured with a spectrophotometer or colorimeter that meets to specified requirements. The color difference is determined using lightness, chroma, and hue difference scales. SAE J1885: A Society of Automotive Engineers recommended practice for accelerated exposure of automotive interior trim components to determine their colorfastness using a water-cooled xenon-arc lamp apparatus. The lamp is equipped with quartz inner and borosilicate outer filters. The amount of heat, relative humidity, and irradiance are controlled to simulate the extreme conditions that may exist inside a motor vehicle. Alternating irradiation is used with a 3.8-hour light cycle (black panel temperature 89◦ C, relative humidity 50%) and a 1.0-hour dark

436

The Effects of UV Light and Weather on Plastics and Elastomers

cycle (38◦ C, 95%). The fading of the specimens is evaluated visually using gray scale or instrumentally by measuring color difference values. SAE J1960: A Society of Automotive Engineers standard test method for accelerated exposure of automotive exterior materials to determine their colorfastness using a water-cooled xenon-arc lamp apparatus. The lamp is equipped with quartz inner and borosilicate outer filters. The amount of heat, moisture (humidity, condensation, or rain), and irradiance are controlled to simulate the extreme conditions that may exist outside a motor vehicle. Alternating irradiation is used with a 2.0-hour light cycle (black panel temperature 70◦ C, relative humidity 50%), including 20 minutes with water spray, and a 1.0-hour dark cycle (38◦ C, 95%) with condensation. The fading of the specimens is evaluated visually using gray scale or instrumentally by measuring color difference values. SAE J1961: A Society of Automotive Engineers standard test method for accelerated outdoor exposure of automotive exterior materials using a solar Fresnel-reflector apparatus to simulate extreme environmental conditions encountered outside a vehicle due to sunlight, heat, and moisture (as humidity, condensation, or rain). The flat Fresnel mirrors of the apparatus focus direct sunlight onto an air-cooled specimen area. The apparatus can be either backed or unbacked and is equipped with a water spray device. Spraying, when used, is done during the night only for 3 minutes at a time with 12-minute dry intervals. The report includes exposure time and radiant exposure. SAE J1976: A Society of Automotive Engineers standard test method for outdoor weathering of exterior automotive materials such as coatings for determination of their weatherability. The method specifies the exposure racks, black boxes, and instrumentation. In Procedure A, test racks with or without backing are positioned at a fixed angle of 5 from the horizontal facing due south. In Procedure B, specimens are exposed in a similarly positioned unheated black. The conditions of the test are recorded by measuring maximum and minimum temperatures and relative humidity values, hours of wetness, and total and UV radiant energy.

SAE J2020: A Society of Automotive Engineers standard test method for accelerated exposure of automotive exterior components using a fluorescent UV lamp and condensation apparatus to simulate extreme environmental conditions on the outside of an automobile due to sunlight, heat, humidity, etc., to predict the performance of exterior materials such as topcoat paint. The condensation in the apparatus is achieved by evaporation of water from a heated pan and exposure of the back sides of the specimens to the cooling effect of ambient air. The specimens are irradiated for 8 hours at 70°C, alternating with 4-hour condensation exposure at 50◦ C. SAE J2212: A Society of Automotive Engineers recommended practice for accelerated exposure of automotive interior trim components to determine their colorfastness using an air-cooled xenon-arc lamp apparatus. The lamp is equipped with a Suprax 1/3 filter system. The amount of heat, relative humidity, and irradiance are controlled to simulate the extreme conditions that may exist inside a motor vehicle. Alternating irradiation (irradiance 80 W/m2 at 300–400 nm wavelength) is used with a light cycle (chamber temperature 62◦ C, relative humidity 50%) and a dark cycle (38◦ C, 95%). The fading of the specimens is evaluated visually using gray scale or instrumentally by measuring color difference values. SAE J2230: A Society of Automotive Engineers standard test method for accelerated exposure of automotive interior trim materials using outdoor underglass sun-tracking temperature and humidity apparatus in which the temperature is controlled in a 24-hour cycle and the humidity is controlled during the dark (night) portion of the cycle. The test is designed to simulate extreme environmental conditions encountered inside a vehicle due to sunlight, heat, and humidity to determine the colorfastness of interior materials such as textiles. The specimen cabinet is covered with 3-mm thick tempered safety glass, maintained facing direct sunlight, and equipped with heaters, humidifiers, UV radiometers, sensors, and a controller. The temperature is maintained at 70◦ C during the day and at 38◦ C (at 75% relative humidity) during the night. The fading of the specimens is evaluated visually using gray scale or instrumentally by measuring color difference values. SAN: See styrene-acrylonitrile copolymer.

437

Glossary of Terms

SAN copolymer: See copolymer.

styrene-acrylonitrile

devices, diaphragms, medical products, adhesives, and sealants. Also called siloxane.

SAN resin: See styrene-acrylonitrile copolymer.

siloxane: See silicone.

scorching: Premature vulcanization of rubber during processing (e.g., on a calender). Resistance of rubber to scorching is tested by heating it while subjecting to shear (e.g., in Mooney viscometer) for a certain period of time. Also called scorch, prevulcanization.

silver streaks: Scars or surface defects on injection moldings caused by the high velocity injection of a stream of molten material into the mold ahead of the normally advancing material front and its premature solidification. Also similar appearance defects resulting from exposure or stress. Also called silver streaking, splay marks.

service life: The period of time required for the specified properties of the material to deteriorate under normal use conditions to the minimum allowable level with the material retaining its overall usability. shelf life: Time during which a physical system, such as a material, retains its storage stability under specified conditions. Also called storage life. short wavelength cutoff: Selectively filtering the radiation from artificial light sources to cut it off in the short UV wavelength region below approximately 300 nm to simulate sunlight. Also called solar cutoff. shortwave UV radiation: On earth’s surface, electromagnetic radiation in the 315–280 nm wavelength region (UV-B) of the solar spectrum. In outer space, radiation in the 280–100 nm wavelength region (UV-C). Also called shortwave UV. shortwave UV: See shortwave UV radiation. silicone: These are rigid thermoplastic and liquid silicones and silicone rubbers consisting of alternating silicon and oxygen atom chains with organic pendant groups, prepared by hydrolytic polycondensation of chlorosilanes, followed by cross-linking. Silicone rubbers have good adhesion, flexibility, dielectric properties, weatherability, barrier properties, and heat and fire resistance, but decreased strength. Rigid silicones have good flexibility, weatherability, soil repelling properties, dimensional stability, but poor solvent resistance. Processed by coating, casting, injection compression, and transfer molding. Used in coatings, electronic

SMA: See styrene-maleic anhydride copolymer. SMA PTB alloy: See styrene-maleic anhydride copolymer PBT alloy. softening point: Temperature at which the material changes from rigid to soft or exhibits a sudden and substantial decrease in hardness. Also called softening temperature, softening range. softening range: See softening point. softening temperature: See softening point. solar cutoff: See short wavelength cutoff. solar radiation: Electromagnetic radiation with wavelengths ranging from 1 × 10−9 cm to 30 km emitted by the sun. The intensity of solar radiation in the short UV wavelength region of the spectrum changes from outer space to the earth’s surface because of the absorption of UV light below approximately 295 nm by the ozone layer of the atmosphere. splay marks: See silver streaks. stability: The ability of a physical system, such as a material, to resist a change or degradation under exposure to outside forces, including mechanical force, heat, and weather. See also degradation. starch: A polysaccharide, consisting of amylose and amylopectin, found in plants such as potatoes. Gels in water. Used in adhesives, textile sizes,

438

The Effects of UV Light and Weather on Plastics and Elastomers

thickeners, and in the manufacture of biodegradable polymers such as polyesters. The grades include technical and edible. starch-modified low density polyethylene: Biodegradable thermoplastic starch-grafted low density polyethylene. starch-modified polypropylene: Biodegradable thermoplastic starch-grafted polyurethane. starch-modified polyurethane: Biodegradable thermoplastic starch-grafted polyurethane. static strip test: An ozone resistance test for rubbers that involves a strip-shaped specimen mounted as a test board, stretched to 15%, and subjected to ozone attack in the test chamber. The results of the test are reported using two digits separated with a virgule. The number before the virgule indicates the number of quarters of the test strip which showed the cracks. The number after the virgule indicates the size of the cracks in length perpendicular to the length of the strip. storage life: See shelf life. storage stability: The resistance of physical system, such as a material, to decomposition, deterioration of properties, or any type of degradation in storage under specified conditions. strain: The per unit change, due to force, in the size or shape of a body with respect to its original size or shape. Note: Strain is nondimensional but is often expressed in terms of length per unit of length or percentage. stress cracking: Appearance of external and/or internal cracks in the material as a result of stress that is lower than its short-term strength. stress pattern: Distribution of applied or residual stress in a specimen, usually throughout its bulk. Applied stress is a stress induced by an outside force (e.g., by loading). Residual stress or stress memory may be a result of processing or exposure. The stress pattern can be made visible in transparent materials by polarized light.

styrene-acrylonitrile copolymer: SAN resins are thermoplastic copolymers of about 70% styrene and 30% acrylonitrile with higher strength, rigidity, and chemical resistance than polystyrene. Characterized by transparency, high heat deflection properties, excellent gloss, hardness, and dimensional stability. Have low continuous service temperature and impact strength. Processed by injection molding, extrusion, injection-blow molding, and compression molding. Used in appliances, housewares, instrument lenses for automobiles, medical devices, and electronics. Also called SAN, SAN resin, SAN copolymer. styrene-butadiene block copolymer: Thermoplastic amorphous block polymer of butadiene and styrene having good impact strength, rigidity, gloss, compatibility with other styrenic resins, water resistance, and processibility. Used in food and display containers, toys, and shrink wrap. styrene-butadiene copolymer: Thermoplastic polymers of butadiene and >50% styrene having good transparency, toughness, and processibility. Processed by extrusion, injection and blow molding, and thermoforming. Used in film wraps, disposable packaging, medical devices, toys, display racks, and office supplies. styrene-maleic anhydride copolymer: Thermoplastic copolymer of styrene with maleic anhydride having good thermal stability and adhesion, but decreased chemical and light resistance. Processed by injection and foam molding and extrusion. Used in auto parts, appliances, door panels, pumps, and business machines. Also called SMA. styrene-maleic anhydride copolymer PBT alloy: Thermoplastic alloy of styrene-maleic anhydride copolymer and polybutylene terephthalate having improved dimensional stability and tensile strength. Processed by injection molding. Also called SMA PTB alloy. styrene plastics: See styrenic resins. styrene polymers: See styrenic resins. styrenic resins: Styrenic resins are thermoplastics prepared by the free-radical polymerization of styrene alone or with other unsaturated monomers.

439

Glossary of Terms

The properties of styrenic resins vary widely with their molecular structure, attaining the high performance level of engineering plastics. Processed by blow and injection molding, extrusion, thermoforming, film techniques, and structural foam molding. Used heavily for the manufacture of automotive parts, household goods, packaging, films, tools, containers, and pipes. Also called styrene resins, styrene polymers, styrene plastics. styrenic thermoplastic elastomers: Linear or branched copolymers containing polystyrene end blocks and elastomer (e.g., isoprene rubber) middle blocks. Have a wide range of hardnesses, tensile strength, and elongation, and good low-temperature flexibility, dielectric properties, and hydrolytic stability. Processed by injection and blow molding and extrusion. Used in coatings, sealants, impact modifiers, shoe soles, medical devices, tubing, electrical insulation, and auto parts. Also called TES. sun hour: One sun hour is an accumulated hour during which the sun is shining with an intensity of 0.823 langleys per min (g cal/cm2 /min). sunshine carbon lamp: Open-flame carbon-arc lamp equipped with glass filters (e.g., Corex D) to better match sunlight. Sunshine lamp emits more radiant energy in the short UV (260–320 nm) wavelength region than the sun on the earth’s surface and therefore can produce unrealistic light exposure results. However, radiation from the sunshine lamp is more realistic than that from the enclosed carbon-arc lamp. Suntest: See Suntest CPS. Suntest CPS: The Suntest CPS (Controlled Power System) is an accelerated weathering chamber of table-top size with automated control and monitoring of temperature and irradiance from an air-cooled xenon-arc tamp with three filter systems: Max UV (high output in short UV wavelength region), Suprax (best sunlight match), and window glass, Cycling of light and dark periods and a water immersion module are available. Produced by Heraeus DSET Laboratories, Inc., Phoenix, Arizona. Also called Suntest.

Super-Maq: A large apparatus for accelerated outdoor weathering equipped with sun-tracking Fresnel mirror-reflecting solar concentrator and water spray. Super-Maq allows testing of the complete components. Produced by Heraeus DSET Laboratories, Inc., Phoenix, Arizona. superficial surface oxidation: Oxidation of the material surface that is relatively insignificant and is restricted to the thin surface layer of the material. surface checks: See checking. surface roughness: Relatively fine spaced surface irregularities, the heights, widths, and directions of which establish the predominant surface pattern. surface tack: Stickiness of a surface of a material such as wet paint when touched. syndiotactic: A polymer molecule in which pendant groups and atoms attached to the main chain are arranged in a symmetrical and recurring fashion relative to it in a single plane. synergistic effect: The boosting effect of one substance on the property of another so that the total effect of both substances in a mixture is greater than the sum of the effects of each substance individually synergistic effect of zinc (e.g., the bis(dibutyldithiocarbamate) on the UV absorption by zinc oxide). T tautomeric: Pertaining to tautomerism (i.e., isomerism in which migration of a hydrogen atom results in two or more structures called tautomers that are in equilibrium). For example, enol and keto tautomers of acetoacetate. tensile elongation: See elongation. tensile heat distortion temperature: See heat deflection temperature. tensile properties: Properties describing the reaction of physical systems to tensile stress and strain. See also tensile property tests.

440

The Effects of UV Light and Weather on Plastics and Elastomers

tensile property tests: Names and designations of the methods for tensile testing of materials. Also called tensile tests. See also tensile properties. tensile strain: The relative length deformation exhibited by a specimen in tension. See also elongation. tensile strength: The maximum tensile stress that a specimen can sustain in a test carried to failure. Note: The maximum stress can be measured at or after the failure or reached before the fracture, depending on the viscoelastic behavior of the material. Also called tensile ultimate strength, ultimate tensile strength, UTS, tensile strength at break, ultimate tensile stress. See also ASTM D638.

thermal properties: Properties related to the effects of heat on physical systems such as materials and heat transport. The effects of heat include the effects on structure, geometry, performance, aging, stress strain behavior, etc. thermal stability: The resistance of a physical system, such as a material, to decomposition, deterioration of properties, or any type of degradation in storage under specified conditions. thermodynamic properties: A quantity that is either an attribute of the entire system or is a function of position, which is continuous and does not vary rapidly over microscopic distances, except possibly for abrupt changes at the boundaries between phases of the system. Also called macroscopic properties.

tensile strength at break: See tensile strength. tensile stress: Tensile stress (or tension) is the stress state leading to expansion; that is, the length of a material tends to increase in the tensile direction. In the uniaxial manner of tension, tensile stress is induced by pulling forces across a bar, specimen, etc. Tensile stress may be increased until the reach of tensile strength, namely the limit state of stress. tensile tests: See tensile property tests. tensile ultimate strength: See tensile strength. terephthalate polyester: Thermoset unsaturated polymer of terephthalic anhydride. TES: See styrenic thermoplastic elastomers. test methods: Names and designations of material test methods. Also called testing methods. test variables: Terms related to the testing of materials such as test method names.

thermoplastic polyesters: Aclass of polyesters that can be repeatedly made soft and pliable on heating and hard (flexible or rigid) on subsequent cooling. thermoplastic polyurethanes: A class of polyurethanes including rigid and elastomeric polymers that can be repeatedly made soft and pliable on heating and hard (flexible or rigid) on subsequent cooling. Also called thermoplastic urethanes, TPUR, TPU. thermoplastic polyurethanes.

urethanes: See

thermoplastic

thermoplastic vulcanizate: A thermoplastic elastomer with a chemically cross-linked rubbery phase, produced by dynamic vulcanization. three-membered heterocyclic compounds: Aclass of heterocyclic compounds containing rings that consist of three atoms.

testing methods: See text methods.

three-membered heterocyclic oxygen compounds: A class of heterocyclic compounds containing rings that consist of three atoms, one or two of which is an oxygen.

tetrafluoroethylene-propylene copolymer: Thermosetting elastomeric polymer of tetrafluoroethylene and propylene having good chemical and heat resistance and flexibility. Used in auto parts.

tinctorial strength: Measure of the effectiveness with which a unit quantity of a pigment or colorant to change the color of a material. Also called tint strength.

441

Glossary of Terms

tint: See color. tint strength: See tinctorial strength. titanium dioxide: A white pigment and opacifying agent, TiO2 , with the greatest hiding power. Exists in two crystal forms: rutile, (with a higher refractive index and opacity) and anatase (with a lower refractive index and opacity). Manufactured in bulk by a sulfation process from the mineral ilmenite or by a chlorination process from the mineral rutile. The pigment is nonmigrating, heat resistant, chemically inert, and lightfast. Used widely in paints, rubber, plastics, paper, synthetic fibers, cosmetics, enamel frits, floor coverings, etc. total solar irradience: The amount of radiant power of sunlight integrated over all its wavelengths per unit area of irradiated surface at point in time. A measure of radiation exposure, it is often expressed in the units of watt per square meter (W/m2 ). toughness: Property of a material indicating its ability to absorb energy by plastic deformation rather than crack or fracture. TPO: See olefinic thermoplastic elastomers. TPU: See thermoplastic polyurethanes. TPU: See urethane thermoplastic elastomers. TPUR: See thermoplastic polyurethanes. transition point: See phase transition point.

tribasic lead maleate: A salt of maleic acid. Highly effective as heat stabilizer for polymeric materials. Limited to use in applications where toxicity and lack of clarity can be tolerated. turbidity: The cloudiness in a liquid caused by a suspension of colloidal liquid droplets or fine solids.

U UHMWPE: See ultrahigh molecular weight polyethylene. ultimate elongation: See elongation. ultimate tensile strength: See tensile strength. ultimate tensile stress: See tensile strength. ultrahigh molecular weight polyethylene: Thermoplastic linear polymer of ethylene with molecular weight in the millions. Has good wear and chemical resistance, toughness, and antifriction properties, but poor processibility. Processed by compression molding and ram extrusion. Used in bearings, gears, and sliding surfaces. Also called UHMWPE. ultramarine blue: An inorganic blue pigment with good alkali and heat resistance, low hiding power, poor acid resistance, and weatherability. Prepared by heating a mixture of sulfur, clay, alkali, and a reducing agent. Used in coatings, inks, rubber, and laundry blues. In low concentration can neutralize yellow tint of white or clear materials.

transition temperature: See phase transition point.

unbacked exposure rack: A rack for holding specimens or specimen panels during exposure testing that is not enclosed from the back.

transmittance: The ratio of the light intensity transmitted by a body to the incident light intensity. Also called percentage light transmittance, light transmission, luminous transmittance, optical transmittance, transmittancy, transparency, transparence.

units of measurement: Systematic and nonsystematic units for measuring physical quantities, including metric and US pound-inch systems. Also called units.

transparency: See transmittance. transparent pigment: Pigments such as some organic pigments having low hiding power.

urea resins: Thermosetting polymers of formaldehyde and urea having good clarity, colorability, scratch, fire, and solvent resistance, rigidity, dielectric properties, and tensile strength, but decreased impact strength and chemical, heat, and moisture

442

The Effects of UV Light and Weather on Plastics and Elastomers

resistance. Must be filled for molding. Processed by compression and injection molding, impregnation, and coating. Used in cosmetic containers, housings, tableware, electrical insulators, countertop laminates, adhesives, and coatings. urethane polymers: See polyurethanes.

sources are many, including fluorescent UV lamps. UV radiation causes polymer photodegradation and other chemical reactions. Note: UV light comprises a significant portion of the natural sunlight. Also called ultraviolet light, UV, UV light, UV radiation. UV stabilizer: See UV absorber.

urethane resins: See polyurethanes. urethane thermoplastic elastomers: Block polyether or polyester polyurethanes containing soft and hard segments. Have good tensile strength, elongation, adhesion, and broad hardness and service temperature ranges, but decreased moisture resistance and processibility. Processed by extrusion, injection molding, film blowing, and coating. Used in tubing, packaging film, adhesives, medical devices, conveyor belts, auto parts, and cable jackets. Also called TPU. urethanes: See polyurethanes. UTS: See tensile strength. UV: See UV radiation. UV absorber: A low-molecular weight organic compound such as hydroxybenzophenone derivatives that is capable of absorbing significant amount of radiant energy in the UV wavelength region, thus protecting the material such as a plastic in which it is incorporated from the damaging (degrading) effect of the energy. The absorbed energy is dissipated by the UV absorber without significant chemical change via tautomerism of hydrogen bonds. Also called UV stabilizer. UV filter: Glass filters that selectively transmit (UV-bandpass filters) or block (longpass filters) UV light. Also called UV filters. UV filters: See UV filter. UV light: See UV radiation. UV radiation: Electromagnetic radiation in the wavelength range 13–400 nm below the short wavelength limit of visible light. The sun is the main natural source of UV radiation on the earth. Artificial

UV wavelength: Any wavelength in the 13–400 nm wavelength region of electromagnetic radiation. UV-A radiation: A portion of UV radiation in the 315–400 nm wavelength range. Causes polymer damage. UV-B radiation: A portion of UV radiation in the 280–315 nm wavelength range. Includes the shortest wavelengths of sunlight found at the earth’s surface. Causes severe polymer damage; absorber by window glass. UV-C radiation: A portion of UV radiation in the 100–280 nm wavelength range. A part of sunlight spectra found only in outer space because of the absorption by the earth’s atmosphere. Germicidal. UV-CON: See fluorescent UV lamp-condensation apparatus. UVA-340 lamp: A fluorescent lamp with peak emission at 340 nm that provides high UV-A radiation output for accelerated indoor lightfastness and weatherability testing of materials such as plastics, nonmetallic coatings, and textiles. The lamp matches closely the sunlight spectrum in the UV wavelength region. UVB-313 lamp: Afluorescent lamp with peak emission at 313 nm that provides high UV-B radiation output for accelerated indoor lightfastness and weatherability testing of materials such as plastics, nonmetallic coatings, and textiles. The lamp does not match closely the sunlight spectrum in the short UV wavelength region. Used for testing of automotive materials. Its output is more stable and higher than that of the FS-40 lamp.

443

Glossary of Terms V veneer: In the rubber industry, a thin film applied on a rubber article to protect it against oxygen and ozone attack. Acts as a migration barrier or is used for decorative purposes. Vicat softening point: The temperature at which a flat-ended needle of prescribed geometry will penetrate a thermoplastic specimen to a certain depth under a specified load using a uniform rate of temperature rise. Note: The Vicat softening point is determined according to the ASTM D1525 test for thermoplastics such as polyethylene that have no definite melting point. Also called Vicat softening temperature. Vicat softening temperature: See Vicat softening point. vinyl ester resins: Thermosetting acrylated epoxy resins containing styrene reactive diluent. Cured by catalyzed polymerization of vinyl groups and cross-linking of hydroxy groups at room or elevated temperatures. Have good chemical, solvent, and heat resistance, toughness, and flexibility, but shrink during cure. Processed by filament winding, transfer molding, pultrusion, coating, and lamination. Used in structural composites, coatings, sheet molding compounds, and chemical apparatus. vinyl resins: Thermoplastics polymers of vinyl compounds such as vinyl chloride or vinyl acetate. Have good weatherability, barrier properties, and flexibility, but decreased solvent and heat resistance. Processed by molding, extrusion, and coating. Used in films and packaging. vinyl thermoplastic elastomers: Vinyl resin alloys having good fire and aging resistance, flexibility, dielectric properties, and toughness. Processed by extrusion. Used in cable jackets and wire insulation. vinylidene fluoride-hexafluoropropylene copolymer: Thermoplastic polymer of vinylidene fluoride and hexafluoropropylene having good antistick, dielectric, and antifriction properties, and chemical and heat resistance, but decreased mechanical strength and creep resistance and poor processibility. Processed by molding, extrusion, and coating.

Used in chemical apparatus, containers, films, and coatings. vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer: Thermosetting elastomeric polymer of vinylidene fluoride, hexafluoropropylene, and tetrafluoroethylene having good chemical and heat resistance and flexibility. Used in auto parts. vulcanizate: Rubber that has been irreversibly transformed from predominantly plastic to predominantly elastic material by vulcanization (chemical curing or cross-linking) using heat, vulcanization agents, accelerants, etc. vulcanizate cross-links: Chemical bonds formed between polymeric chains in rubber as a result of vulcanization. W warpage: See warping. warping: Dimensional distortion or deviation from the intended shape of a plastic or rubber article as a result of nonuniform internal stress (e.g., caused by uneven heat shrinkage). Also called warpage. water swell: Expansion of material volume as a result of water absorption. watt: One watt is 0.07 gram calories per minute. weatherometer: An apparatus for accelerated indoor testing of weatherability of materials such as plastics. Equipped with carbon- or xenon-arc lamps having glass filters to simulate the sunlight and with a water spraying device. Most models allow controlling and monitoring temperature and humidity inside the apparatus as well as alternating dark and light cycles of exposure. wet bulb depression: The difference between the temperatures shown by the wet and dry thermometers of a psychrometer, an instrument for measuring the content of moisture (humidity) in the air. whiting: A finely divided form of calcium carbonate (CaCO3 ) obtained by milling high-calcium

444

The Effects of UV Light and Weather on Plastics and Elastomers

limestone, marble, shell, or chemically precipitated calcium carbonate. Used as an extender filler in plastics and rubbers.

X xenon arc lamp: An inert gas xenon-filled quartz tube with two electrodes to produce an electric arc discharge that emits radiation in the 200–1200 nm wavelength region. Can be air- or water-cooled. Equipped with glass filters to selectively block short wavelength UV light to simulate sunlight. Usually there are two filters—inner and outer—one of which is made of borosilicate glass. In the water-cooled lamps, cooling demineralized water flows between the inner and outer filters. Used in the apparatus for accelerated indoor testing of weatherability and lightfastness of materials, these lamps produce more realistic degradation than carbon arc lamps. Also called xenon lamp. xenon arc weatherometer: An apparatus for accelerated indoor testing of weatherability of materials such as plastics. Equipped with one or three wateror air-cooled xenon arc lamps with borosilicate glass filters to simulate sunlight and with a water spraying device. Produces more realistic degradation that carbon arc weatherometers. Most models allow controlling and monitoring temperature and humidity inside the apparatus as well as alternating dark and light cycles of exposure. Among the manufacturesof xenon arc weatherometers is Atlas Electric Devices Co., Chicago, Illinois. The Atlas Ci65 model has a two-tier inclined specimen rack with the xenon-arc lamps located vertically at the central axis of the racks. Also called Ci65 xenon arc weatherometer, Atlas Ci65 xenon arc weatherometer.

xenon lamp: See xenon arc lamp. Xenotest 1200: A computerized chamber for accelerated weatherability testing of materials manufactured by Heraeus DSET Laboratories, Inc., Pheonix, Arizona. Equipped with three air-cooled xenon-arc lamps, an optical filter system for selectively blocking UV light, rotating specimen holders, a sample spray system, specimen back side cooling for dew simulation, rain water heating system, and control systems for irradiance, temperature, speed, and humidity of inside air.

Y yellowing: Developing of yellow color in nearwhite or near-transparent materials such as plastics or coatings as a result of degradation on exposure to light, heat aging, weathering, etc. It is usually measured in terms of yellowness index. yellowness index: A measure of the tendency of materials such as plastics to become yellow as a result of long-term exposure to light, irradiation, etc.

Z zinc oxide: An amorphous white powder, ZnO, used as a pigment in plastics and coatings, as an activator of rubber vulcanization accelerators, and as reinforcing filler. Having the greatest UV light absorbing power of all commercially available pigments, it can act as a UV stabilizer, especially in synergistic mixtures with organics such as zinc bis(dibutyldithiocarbamate).

References 1. Kapton Polyimide Film, E.I. DuPont de Nemours, 2005. http://www.dupont.com/kapton/general/ radresistance.html

12. Weather: Color and Fading Properties, UMG ABS Ltd., 2005. http://www.umgabs.co.jp/en/ solution/trouble/t_61.htm

2. Weathering of Tenite Butyrate, Eastman Chemical Co., 2005. http://www.eastman.com/Online_ Publications/pp104/Index.htm

13. Luran S Acrylonitrile Styrene Acrylate Product Line, Properties, Processing, supplier design guide (B 566 e / 11.90), BASF Aktiengesellschaft, 1990.

3. Ashton, H.E., CBD-122. Radiation and Other Weather Factors, Canadian Building Digest. http:// irc.nrc-cnrc.gc.ca/pubs/cbd/cbd122_e.html

14. UV Light Stabilization of ABS, SpecialChem S.A., 2005. http://www.specialchem4polymers.com/ tc/UV-Light-Stabilizers/index.aspx?id=2276

4. Properties of Terluran Standard, BASF Corporation, 2004. http://www.plasticsportal.net/wa/EU/ Catalog/ePlastics/doc/BASF/prodline/terluran_ standard/properties.xdoc

15. Rovel Weatherable Polymers, supplier technical report (301-621-285), Dow Chemical Company, 1985.

5. UV Damage to Polymers, U.S. Global Change Research Information Office, 2005. http://www. gcrio.org/UNEP1998/UNEP98p62.html ®

6. Luran S Acrylonitrile-styrene-acrylate copolymer (ASA and ASA+PC) Applications, Range, Properties, Processing, BASF Corporation, 2004. 7. UV Stabilization Of Aromatic Pellethane Thermoplastic Polyurethane Elastomers, supplier technical report (306-00439-1293 SMG), Dow Chemical Company, 1993. 8. Laboratory Weathering Testing, Atlas Material Testing Solutions, 2005. http://www.atlas-mts.com/ products/laboratory-weather-testing/ 9. Accelerated Weathering by QUV, Plastics Technology Laboratory, 2005. http://www.ptli.com/ testlopedia/tests/QUV-D4329.asp 10. Choice of Lamps for the QUV, Q-Panel Lab Products, 2005. http://www.q-panel.com/UserFiles/ File/PDFs-EN/LU8160_2004.pdf 11. Orem, J.H. and Sears, J.K., Flexible Poly (Vinyl Chloride) For Long Outdoor Life, Monsanto Chemical Company, 2005. http://www.geomembrane.com/ TechPapers/OutdoorExposure.htm

16. Luran S Acrylonitrile Styrene Acrylate Product Line, Properties, Processing, supplier design guide (B 566 e / 10.83), BASF Aktiengesellschaft, 1983. 17. Business Equipment Externals Comparative UV===dE Data, supplier technical report (GH-110792/19), General Electric Company, 1992. 18. Cycolac ABS Resin Design Guide, supplier design guide (CYC-350 (5/90) RTB), General Electric Plastics, 1990. 19. Engineering Design Guide To Rigid Geon Custom Injection Molding Vinyl Compounds, supplier design guide (CIM-020), BFGoodrich Geon Vinyl Division, 1989. 20. Duracap Vinyl Capstock Compounds, supplier marketing literature (DC-001), BFGoodrich Geon Vinyl Division, 1988. 21. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994. 22. Weatherability of Cycolac Brand ABS—Technical Publication P-405, supplier technical report (82035M), General Electric Company, 1982. 23. Shinko-Lac ASA T Weatherable And Heat Resistant ASA Resin, supplier design guide, Mitsubishi Rayon Company.

446

The Effects of UV Light and Weather on Plastics and Elastomers

24. Introducing Superior UV Stability With Good Looks That Last In Business Machine Housings, supplier marketing literature (7110), Monsanto Chemical Company, 1990. 25. Cycolac/Geloy Products and Markets (CYC 600), GE Plastics, 2005. http://www.geplastics.com/ resins/global/pdf/product/americas/geloy_market. pdf 26. Hostaform Report 118, Ticona, 2005. http:// www.ticona.com/tools/search/lit_details.cfm? docid=1243 ®

27. Celcon Acetal Copolymer Ultraviolet Resistant Grades, Ticona, 2005. http://www.ticona.com/ tools/search/lit_details.cfm?docid=38 28. Inform Automotive, Ticona, 2005. http://www. ticona.com/tools/search/lit_details.cfm?docid=323 29. DuPont Delrin Design Guide Module III, H-57472 (95.1), E.I. DuPont de Nemours. 30. DuPont Delrin Design Information, supplier literature, L-10464, E.I. DuPont de Nemours, 2003. 31. Ultraform Outdoor Exposure—Unpublished Data, supplier technical report, BASF, 1993. 32. Celcon Acetal Copolymer, supplier design guide (90-350 7.5M/490), Hoechst Celanese Corporation, 1990. 33. Engineering Plastics Acetal Copolymer— Iupital, supplier design guide (M.G.C.91042000P.A.), Mitsubishi Gas Chemical Company, Inc., 1991. 34. Topics In Chemistry—BASF Plastics Research And Development, supplier technical report, BASF Aktiengesellschaft, 1992. 35. Cycolac/Geloy Products and Markets, GE Plastics, 2005. http://www.geplastics.com/resins/global/ pdf/product/americas/geloy_market.pdf ®

36. Luran S (ASA) for the leisure industry—a material for pleasure, KTCS 9700e 04.97, BASF Aktiengesellschaft, 2005. http://www2.basf.de/ basf2/html/plastics/images/pdfs/engl/copolymere/ Luran_S_leisure.pdf?id=Y3Su36P3abcp0w* 37. Acrylite® GP Acrylic Sheet Fluorescent Colors and Weatherability, CYRO Industries, 2005. http://cyro.custhelp.com 38. Plexiglas® Acrylic Molding Resin, The Arkema Group, 2005. http://www.products.arkemagroup.

com/atoglas/technicalinfo/Properties/Weathering/ weathering.cfm 39. Comparing the weatherability of ACRYLITE Sheet vs. polycarbonate sheet, CYRO Industries, 2005. http://cyro.custhelp.com/cgi-bin/cyro.cfg/php/ enduser/std_adp.php?p_faqid=939&p_created= 1000154166 40. UV Stability of NAS® And ZYLAR® , Nova Chemicals, 2005. http://www.novachem.com/zylar/ Tech_bulletins_PDFs/0720.pdf 41. Lucite® Resins & Polymers, Lucite International, 2005. http://www.luciteinternational.com/ acrylic_resins.asp 42. Weathering resistance of polymeric materials, United States Patent 6689840. http://www. freepatentsonline.com/6689840.html 43. Ebnesajjad, S., Fluoropolymers, Vol. 2, pp. 417– 420, Plastics Design Library, William Andrew Inc., 2003. 44. Fluoro-Mar Properties & Typical PTFE & Teflon® Properties, Fluoro-Plastics, 2005. http:// www.fluoropolymerproducts.com/index.htm 45. Ultrason E, Ultrason S Product Line, Properties, Processing, supplier design guide (B 602 e/10.92), BASF Aktiengesellschaft, 1992. 46. Odevsitesi.com, Fluoropolymers, 2005. http:// www.odevsitesi.com/6/2103.htm 47. Fluon from Ashai Glass Fluoropolymers, 2005. www.fluoropolymers.uk.com/CommercialPDFs/ eng.pdf 48. Fluoropolymers, Andrew Roberts, Inc., 2005. http://www.andrewroberts.com/MFA.htm 49. Solvay Solexis, Supplier Test Data, June 2005. 50. Fluoropolymers, All Plastics, 2005. http://www. allplastics.com.au/materials/ptfe 51. Kynar Transparent UV Opaque Films, Atofina, 2005. http://staging.atofinachemicals.com/literature/ pdf/251.pdf 52. Building and Architecture Films and Sheets, Solvay Solexis, 2005. http://www. solvayfluoropolymers.com/market/application/ 53. Kynar Polyvinylidene Fluoride, supplier technical report (PL705-Rev4-1-91), Atochem North America, Inc., 1991.

References

54. Kynar 500, Atofina Chemicals, 2005. 55. Thermal And Other Properties of Halar Fluoropolymer, supplier technical report (GHG), Ausimont. 56. Haylar 5000, Solvay Solexis, 2005. http://www. pvdf.solvaysolexis.com/products/product_detail/ 57. Aclar Performance Films, supplier technical report (SFI-14 Rev. 9-89), Allied Signal Engineered Plastics, 1989. 58. Plas-Tech Coatings, Inc., 2002. http://www. plastechcoatings.com/halar.htm 59. Tefzel Fluropolymer Design Handbook, supplier design guide (E-31301-1), Du Pont Company, 1973. 60. DuPont High Performance Films, DuPont de Nemours, 2005. http://www.dupont.com/teflon/ films/H-04323-1.html 61. Product and Performance Guide for Tedlar® PVF Film in the Flexible Sign and Awning Market, (12/95) 244322B, DuPont de Nemours. 62. Tedlar SP® Polyvinyl Fluoride Film, (4/97) 300131A, DuPont de Nemours. 63. Tedlar Chemical Properties, Optical Properties and Weathering Performance, (10/95) 234444B, DuPont de Nemours. 64. Ionomers, The Macrogalleria, Polymer Science Learning Center, Department of Polymer Science, The University of Southern Mississippi, 2005. http://www.pslc.ws/macrog/ionomer.htm 65. Resistance to Ultraviolet Irradiation for Surlyn Ionomer Resins, supplier technical report (E-78693103520/A), DuPont Company, 1986.

447 70. Weatherability of Noryl Resins, supplier technical report, General Electric Company, 1992. 71. Nylon, Machine Design, Penton Media, Inc., 2005. http://www.machinedesign.com/BDE/ materials/bdemat2/bdemat2_29.html 72. Improved UV Stabilized Nylon, 2005. www.yet2.com/app/utility/external/indextechpak/ 26959+nylon+UV&hl=en&start=14 73. Ultramid Nylon Resins Product Line, Properties, Processing, supplier design guide (B 568/1e/ 4.91), BASF Corporation, 1991. 74. Capron Nylon Effect Of Exposure To Sunlight, supplier technical report (842-149), Allied Chemical, 1976. 75. Cloud, P. and Theberge, J., Glass-Reinforced Thermoplastics, Thermal And Environmental Resistance Of Glass Reinforced Thermoplastics, supplier technical report, LNP Corporation, 1982. 76. Ube Nylon Technical Brochure, supplier design guide (1989.8.1000), Ube Industries, Ltd., 1989. 77. IXEF Reinforced Polyarylamide Based Thermoplastic Compounds Technical Manual, supplier design guide (Br 1409c-B-2-1190), Solvay, 1990. 78. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994. 79. Grilamid TR55, EMS Grivory, 2005. http:// www.emsgrivory.com/ 80. Grilamid TR55 Transparent Nylons, supplier design guide (GRI-104), EMS Chemie. 81. Grilamid TR, Robert Meyer zu Westram, ADC I&O, supplier test data, September 2005.

66. Weatherability, supplier marketing literature (E-53525), DuPont Company, 1983.

82. EMS Grilamid TR Weathering, supplier test data, July 2005.

67. Noryl PPO Resin, GE Plastics, 2005. http://www.geplastics.com/resins/ProductGuides/ NorylPPO/Introduction.html

83. Tensile Strength And Color Difference After Weathering—Unpublished Test Results, supplier technical report, EMS-Chemie.

68. Polymer Data File: Polyphenylene Oxide (modified)—PPO (Noryl), Tangram Technology Ltd., 2001. http://www.tangram.co.uk/TI-PolymerPPO.html#GP

84. Thanki, P.N., Photo-oxidative Degradation in Nylon 66 (Chapter 3), PhD thesis. http:// www.angelfire.com/pa5/parag/CHAPTER3/ CHAPTER3.pdf

69. Terluran Product Line, Properties, Processing, supplier design guide (B 567e/(8109) 9.90), BASF Aktiengesellschaft, 1990.

85. DuPont Nylon Twine Strength Information and Specifications, Gourock, 2005. http://gourock.com/ DuPont%20vs%20Standard.htm

448

The Effects of UV Light and Weather on Plastics and Elastomers

86. Ultramid T Polyamide 6/6T (PA) Product Line, Properties, Processing, supplier design guide (B605 e/3.93), BASF, 1993. 87. UV Light Stabilization of Polycarbonate and Blends, SpecialChem S.A., 2005. http://www.special chem4polymers.com/tc/UV-Light-Stabilizers/ index.aspx?id=2278 88. Lexan PC Resin Brochure, GE Plastics, 2004. http://www.geplastics.com/resins/techsolution/ PDFs/Lexan_2004.pdf 89. GE Plastics Press Room Lexan SLX, GE Plastics. http://www.gelexan.com/press_pack/ 04_01_29_d.html 90. Lexan EXL, GE Plastics, 2005. http://www. gelexan.com/resins/materials/lexanexl/index.html 91. Physical Properties, Calibre, Dow Polycarbonate, LG Dow Polycarbonate, 2003. http://www. lg-dow.com/tech/Wheather.htm 92. Comparison Of Plastics Used In Glazing, Signs, Skylights And Solar Collector Applications— Technical Bulletin 143, competitor’s technical report (ADARIS 50-1037-01),Aristech Chemical Corporation, 1989.

(HCER 91-343/10M/692), Hoechst Celanese Corporation, 1992. 100. DuPont Rynite Global Product, E.I. DuPont de Nemours, 2005. http://plastics.dupont.com/ NASApp/myplastics/Mediator?id=119&locale= en_US 101. Rynite Design Handbook for DuPont Engineering Plastics, supplier design guide (E-62620), DuPont Company, 1987. 102. Liquid Crystal Polymers, Machine Design, Penton Media, Inc., 2005. http://www.machinedesign. com/BDE/materials/bdemat2/bdemat2_12.html 103. Vectra Polymer Materials, supplier design guide (B 121 BR E 9102/014), Hoechst AG, 1991. 104. Ardel Polyarylate, Westlake Plastics Company, 2005. http://www.westlakeplastics.com/viewresult. asp?prodname=Ardel%AE&busgrp=HP 105. Upimol Polyamide Shape, supplier technical report, UBE Industries. 106. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994.

93. Ardel Polyarylate—The Tough Weatherable Thermoplastic, supplier marketing literature (F47141C), Union Carbide Corporation.

107. Torlon Polyamide-imide Design Guide, Solvay Advanced Polymers, L.L.C., 2003 http://www. solvayadvancedpolymers.com/static/wma/pdf/9/9/7/ TDG_2003.pdf

94. Cycoloy PC/ABS Resin Product Brochure, GE Plastics, 2005. http://www.geplastics.com/resins/ techsolution/PDFs/Cycoloy_2004.pdf

108. Lexan PC Resin Brochure, GE Plastics, 2005. http://www.geplastics.com/resins/techsolution/ PDFs/Lexan_2004.pdf

95. Celanex PBT, Ticona Engineering Polymers, 2005. http://www.ticona.com/index/products/ pbt.htm

109. Ultem Design Guide, supplier design guide (ULT-201G (6/90) RTB), General Electric Company, 1990.

96. UV Light Stabilization of PBT, SpecialChem S.A., 2005. http://www.specialchem4polymers.com/ tc/UV-Light-Stabilizers/index.aspx?id=2279

110. Victrex PEEK, supplier design guide (VK2/0586), ICI Advanced Materials, 1986.

97. Weatherability of Ultradur, BASF Aktiengesellschaft, 2005. https://www.plasticsportal.net/wa/ EU/Catalog/ePlastics/doc/BASF/prodline/ultradur/ weatherability_ultradur.xdoc

111. Polyolefins, Machine Design, 2005. http://www. machinedesign.com/BDE/materials/bdemat2/ bdemat2_21.html

98. DuPont Dow Elastomers Hypalon, 2005. www.matweb.com

112. UV Effect on Polyethylene, Tip from Technology, Exxon Mobil, 2003. http://www.exxonmobilpe. com/Public_Files/Polyethylene/Polyethylene/ NorthAmerica/Technology_Rotomolding.pdf

99. Celanex Thermoplastic Polyester Properties and Processing (CX-1A), supplier design guide

113. UV Light Stabilization of Polyolefin for Molded Application, SpecialChem USA, 2005.

449

References

http://www.specialchem4polymers.com/tc/UV-LightStabilizers/index.aspx?id=2272 114. Cyasorb UV-531, UV-3346, Combination Concentration Guidelines For PE Greenhouse Film Products, supplier technical report, American Cyanamid Polymer Additives, 1994. 115. Marlex Polyethylene Weatherability, supplier technical report (TIB3 (78-89 02)), Phillips 66 Company, 1989. 116. Ultranox 626/626A Antioxidants, supplier technical report (CA-243B), General Electric specialty Chemicals, 1990. 117. Hostalen GUR—Effects Of Heat And Light Aging, supplier technical report, (HCC Rev 1/90), Hoechst Celanese Corporation, 1990. 118. Stein, H.L., Ultrahigh Molecular Weight Polyethylenes (UHMWPE), Engineered Materials Handbook, Vol. 2, Engineering Plastics, reference book, ASM International, 1998. 119. Lupolen, Lucalen Product Line, Properties, Processing, supplier design guide (B 581 e/(8127) 10.91), BAS Aktiengesellschaft, 1991 120. EVA Greenhouse Film—Pesticide Study, supplier technical report, Cyanamid Polymer Additive. 121. UV Light Stabilization of Polypropylene forAutomotive, SpecialChem S.A., 2005. http://www. specialchem4polymers.com/tc/UV-LightStabilizers/index.aspx?id=2273 122. Ultraviolet Resistance, PPTF06 12/03, Stevens Geomembranes/JPS Elastomerics. www. stevensgeomembranes.com 123. Microcal Spa C110S For Polypropylene, supplier technical report (APP033 P1), ECC International, 1993. 124. Pauquet, J.R. and Berthelon, N., Effect Additives for Polyethylene Fibers, Ciba Specialty Chemicals, Basel, Switzerland, 2002. http://www. cibasc.com/centexbel2002.pdf 125. “TPX” Polymethylpentene, supplier design guide (88.06.3000.Cl.), Mitsui Petrochemical Industries, Ltd., 1986. 126. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994.

127. Ryton Polyphenylene Sulfide Compounds Engineering Poperties, supplier design guide (TSM266), Phillips Chemical Company, 1983. 128. Properties of Polystryol Polystyrene, BASFPlastics Portal, 2005. https://www.plasticsportal.net/ wa/EU/Catalog/ePlastics/doc/BASF/prodline/ polystyrol/properties.xdoc#N10011 129. Polystyrol Product Line, Properties, Processing, supplier design guide (B 564 e/2.93), BASF Aktiengesellschaft, 1993. 130. Blaga, A., CBD-167. Rigid Thermoplastic Foams, Canadian Building Digest, 2005. http://irc.nrc-cnrc.gc.ca/cbd/cbd167_e.html 131. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994. 132. Open supplier info. 133. Styron 6000 Ignition Resistant Polystyrene Resins, supplier marketing literature (301-01673192R SMG), Dow Chemical Company, 1992. 134. Styrosun, Nova Chemicals, 2005. http://www. novachem.com/STYROSUN/index.cfm 135. High Impact Polystyrene—HIPS UV Stabilised, Azom, Inc. 2005. http://www.azom.com/ details.asp?ArticleID=425 136. UV Light Stabilization of HIPS, SpecialChem S.A., 2005. http://www.specialchem4polymers.com/ tc/UV-Light-Stabilizers/index.aspx?id=2277&or= s80038_403_2277&q=polystyrene+ 137. Udel Polysulfone Design Guide, Solvay Advanced Polymers, 2004. http://www.solvay advancedpolymers.com/static/wma/pdf/4/0/6/ UDG2004.pdf 138. Polyethersulfone (PES) Technical Literature, Mitsui Chemicals, 2005. http://www.mitsuichem.co.jp/info/pes_e/pes_e_pdf/pes_t_ brochuredoc.pdf 139. Luran Product Line, Properties, Processing, supplier design guide (B 565 e/10.83), BASF Aktiengesellschaft, 1983. 140. Tyril SAN Engineering And Fabrication Guidelines, supplier design guide (301-665-1085) Dow Chemical Company, 1985.

450

The Effects of UV Light and Weather on Plastics and Elastomers

141. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994. 142. K-Resin SB Copolymers UV Stabilization— Plastics Technology Technical Center Report #412, supplier technical report (778-93 K 01), Phillips Petroleum Company, 1994.

155. Chapman, G., New Technologies And Applications For Starch Containing Degradable Plastics, supplier technical report, Ecostar International L.P. 156. MaterBi, Novamont.com 2005. 157. Rapidcoat, 2005. http://www.rapidcoat.com/ Guidelines.htm

143. Svoboda, R.D., Polymeric Plasticizers for Higher Performance Flexible PVC, The C.P. Hall Company, 2005. http://www.geomembrane.com/ TechPapers/Polymeric%20Plasticizers.htm

158. Powder Coaters Manual, 2005. http://www. coatings.de/pcmanual/manual/kap1-2.pdf

144. Extend life expectancy of flexible PVC and make it the choice for construction applications, SpecChem S.A., 2005. http://www.specialchem4 polymers.com/tc/solutionsdatasheet.aspx?t=294

160. UV Light Stabilization of Unsaturated Polyester (UPR), 2005. http://www.specialchem4 polymers.com/tc/UV-Light-Stabilizers/index.aspx? id=2284

145. Chlorinated Polyvinyl Chloride—CPVC Chlorinated PVC,AZoM™, 2005. http://www.azom.com/ details.asp?ArticleID=775

161. Reaction Injection Molding, Armstrong Mold Company, 2005. http://www.armstrongmold.com/ pages/reaction.html

146. Rovel Weatherable High Impact Polymers, supplier marketing literature (301-622-285) Dow Chemical Company, 1985.

162. Window Encapsulation, Recticel North America, 2005. http://www.recticelna.com/window_ encap.htm

147. Novaloy 9000, Bamberger Polymers, 2005. http://bambergerpolymers.matweb.com/Specific Material.asp?bassnum=PNV100&group=General 148. Weathering resistance of polymeric materials, United States Patent 6689840, 2005. http://www. freepatentsonline.com/6689840.html

163. Carver, T.G., Kubizne, P.J., and Huys, D., Reaction injection Molded Modular Window Gaskets Using Light Stable Aliphatic Polyurethane, Polyurethanes: Exploring New Horizons—Proceedings Of The SPI 30th Annual Technical/Marketing Conference, conference proceedings, The Society Of the Plastics Industry, Inc.

149. Novatec Novaloy 9000, supplier marketing literature, Novatec Plastics & Chemicals Co.

164. Colo-Fast Spray, supplier marketing literature, Recticel n.v., s.a.

150. Supplier Written Correspondence, Kleerdex Company, 1994.

165. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994.

151. Bayblend FR Resins for Business Machines and Electronics, supplier marketing literature (55D808(5)J 313 10/88), Mobay Corporation, 1988.

166. The Macrogalleria, Polymer Science Learning Center, Department of Polymer Science, The University of Southern Mississippi, 2005. http://www.pslc.ws/macrog.htm

152. Pulse 1745 Polycarbonate/ABS Resin For Computer And Business Equipment, supplier marketing literature (301-00425-793 SMG), Dow Chemical Company, 1993. 153. Yang, S.R., Studies on Degradable Plastics for Agriculture in Taiwan, Tainan District Agricultural Research and Extension Station, 70, Muchang, Sinhua 712, Tainan County, Taiwan, ROC. 154. ECOSTARplus Leads The Way, supplier written correspondence, Ecostar International L.P., 1993.

159. Plasticolors, 2005. http://www.plasticolors. com/TechDept/Papers/ExteriorCompositePaper.htm

167. Thermoplastic Elastomers, Polymer Science Learning Center and the Chemical Heritage Foundation, 2000. http://www.pslc.ws/tour/rubber/sepisode/ tpe.htm 168. Tyrin for Use in Rigid PVC Window Profile Formulations, 2005. http://www.dupontdow.com/literature/tyrin/090017a280137407.pdf 169. Tyrin CPE Elastomers, supplier design guide (306-00094-1190RJD), Dow Chemical Company, 1990.

References

170. Santoprene.com

451

171. Fornprene, 2005. http://www.softerspa.com/ eng_prodotti_tpe_forprene.htm

186. Kraton D and G, Kraton Polymers, 2005. http://www.kraton.com/kraton/generic/menu.asp? ID=64

172. DuPont Dow Elastomers Engage® Polyolefin Elastomer, 2005. www.matweb.com

187. Kraton Thermoplastic Rubber, supplier design guide (SC: 198-89), Shell Chemical Company, 1989.

173. Weathering of Santoprene Thermovulcanizate Black Ultraviolet Grades, Santoprene Specialty Products, Exxon Mobil Chemical Co., 1992.

188. Evoprene® G Series Thermoplastic Elastomer, 2005. www.matweb.com

174. Accelerated Weathering of Santoprene Thermovulcanizate Black High Flow Grades, Santoprene Specialty Products, Exxon Mobil Chemical Co., 1997 175. Forprene By S.O.F.TER., supplier marketing literature (RDS 049/9240), Evode Plastics. 176. Ozone Resistance Of Santoprene Rubber, supplier technical report (TCD01787), Advanced Elastomer Systems, 1986.

189. Dow Pellethane® 2103-80AEF Polyurethane Elastomer, 2005. www.matweb.com 190. Product Information, Noveon, 2005. http:// www.estane.com/featuresBenefits/productTable. asp#58000 191. Estane Thermoplastic Polyurethane Product Data Sheets, supplier technical report (BFG-15512J), The BFGoodrich Company. 192. Elastollan Design And Processing Guide, supplier design guide, BASF Corporation, 1993.

177. Engage Polyolefin Elastomers, supplier marketing literature (305-01995-1293 SMG), Dow Chemical Company, 1993.

193. Chemigum Elastomers, Elastomeric Modifiers, Eliokem, 2003. http://www.eliokem.com/prod_ emod.php

178. Lower Costs, Increase The Service Life Of Your Expansion Joints And Water Stoppers, supplier marketing literature, Advanced Elastomer Systems, 1993.

194. Florida Weathering Of Chemigum TPE, supplier technical report (TPE 06-0292/498900-2/92), Goodyear Chemicals, 1992.

179. Set A New Standard Of Performance For Your Non-Residential Glazing Seals, supplier marketing literature, Advanced Elastomer Systems, 1993. 180. Hytrel Product and Properties Guide, DuPont Engineering Polymers, H-81089 (99.11). 181. Hytrel Technical Notes—“Weather Protection of Hytrel with Carbon Black”, supplier technical report (1-48), DuPont Company. 182. Pigmentation And Weathering Protection Of “Hytrel”, supplier technical report (HYT303(R1)/E-73191) DuPont Company, 1985. 183. Hytrel—Resistance To Mildew And Fungus, supplier technical report (E-84285), Du Pont Company. 184. Styrolux SBS, BASF Chemical Company, 2005. https://www.plasticsportal.net/wa/EU/Catalog/ ePlastics/doc/BASF/prodline/styrolux/styrolux_ other_properties.xdoc 185. Styrolux Product Line, Properties, Processing, supplier design guide (B 583 e/(950) 12.91), BASF Aktiengesellschaft, 1992.

195. Rubbers and Elastomers, RoyMech, 2005. http://www.roymech.co.uk/Useful_Tables/Matter/ Rubbers.html 196. The Elastomers, Timco Rubber Products Inc., 2003. http://www.timcorubber.com/definitions/ index.asp 197. Properties, R.J. Vedovell Incorporated, 1999. http://www.vedovell.com/prop1.html 198. Butyl Polymers, Exxon Mobil Chemical, 2002. http://www.exxonmobilchemical.com/Public_ Products/Butyl/Butyl_Polymers/Worldwide/Btl_ ProductFrontPage.asp 199. Bromobutyl Rubber Optimizing Key Properties, supplier marketing literature, Exxon Chemicals. 200. BROMO XP-50 Optimizing Key Properties, supplier marketing literature, Exxon Chemicals. 201. Fusco, J.V. and Hous, P., Butyl And Halobutyl Rubbers, reference book, Exxon Chemicals, 1987. 202. Dupuis, I.C. and Cumberland, D.W., Compounding “Hypalon” For Weather Resistance, supplier technical report (E-23070-1 HP-515.1), DuPont Company, 1987.

452

The Effects of UV Light and Weather on Plastics and Elastomers

203. Weatherability Of Santoprene Rubber Compared To Other Materials, supplier technical report (TCD01588), Advanced Elastomer Systems, 1988.

Applications, 8th Conference On Roofing Technology, conference proceedings, National Bureau of Standards and NRCA, 1987.

204. Weathering Data of Santoprene Thermoplastic Rubber (Black Grades) Versus Standard Thermoset Rubbers, supplier technical report (TCD03787), Monsanto Company, 1987.

210. Japan Synthetic Rubber JSR RB, supplier design guide, Japan Synthetic Rubber Company.

205. Polimeri Dutral® , Polimeri Europa, 2005. http://www.polimerieuropa.com/200Page.lasso? uk7441 206. Dutral And The Automotive Industry, supplier marketing literature, Montedison Specialty Chemicals Ausimont. 207. Baseden, G.A., Compounding Nordel Hydrocarbon Rubber For Good Weathering Resistance, supplier technical report (E-88779/587 118 545/A), Du Pont Company, 1987. 208. Weathering Of Santoprene Thermoplastic Rubber Black Ultraviolet Grades, supplier technical report (TCD00592), Advanced Elastomer Systems, 1992. 209. Gish, B.D. and Jablonowski, T.L., Weathering Tests for EPDM Rubber Sheets for Use in Roofing

211. Natsyn Polyisoprene Rubber, supplier design guide (700-821-980-540), Goodyear Chemicals, 1988. 212. Elastuff 101/102, United Coatings, 2005. http://www.unitedcoatings.com/products/rooting/ diathon/ELASTUFF.htm 213. Cyanamid TMXDI (META) Aliphatic Isocyantate, supplier marketing literature (90-4-849 3k 5/90 - UPT-061), American Cyanamid Company Urethane Chemi, 1990. 214. Rubber Physical and Chemical Properties, Dow Corning Corporation, 2005. http://www. dowcorning.com/content/rubber/rubberprop/ rubber_weather.asp 215. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994. 216. Supplier Technical Data provided for The Effect of UV Light and Weather, First Edition, 1994.

Trade Name Index Advanced Elastomer Systems Santoprene—Chapter 62 American Cyanamid TMXDI (META)—Chapter 76 Arkema Kynar—Chapter 12 Atoglas Plexiglas—Chapter 5 Ausimont Dutral-TER—Chapter 72 BASF Capron—Chapter 20 Elastollan—Chapter 66 Luran—Chapter 1, 4, 49 Polystyrol—Chapter 45 Styrolux—Chapter 64 Terluran—Chapter 1 Ultradur—Chapter 29 Ultraform—Chapter 3 Ultramid—Chapter 20, 22, 24 Ultrason—Chapter 48 Bayer Bayblend—Chapter 55 Chevron Phillips Marlex—Chapter 39 Ryton—Chapter 44 K-Resin—Chapter 50 Cyro Acrylite—Chapter 5 Cyrolon—Chapter 5 Dow Calibre—Chapter 27 Engage—Chapter 62 Pellethane—Chapter 66 Pulse—Chapter 55 Styron—Chapter 46 Tyril—Chapter 49 Tyrin—Chapter 61

Dow Corning Silastic—Chapter 77 DuPont Delrin—Chapter 3 Hypalon—Chapter 70 Hytrel—Chapter 63 Kapton—Chapter 33 Kevlar—Appendix 1 Neoprene—Chapter 73 Nordel—Chapter 72 Rynite—Chapter 30 Surlyn—Chapter 17 Tedlar—Chapter 16, Appendix 1 Teflon—Chapter 9, Appendix 1 Tefzel—Chapter 15 Zytel—Chapter 23 Eastman Tenite—Chapter 7 Eliokem Chemigum—Chapter 67 EMS Grivory Grilamid—Chapter 21 Exxon Vistalon—Chapter 72 GE Plastics Cycolac—Chapter 1, 2 Cycoloy—Chapter 28 Geloy—Chapter 2, 4 Lexan—Chapter 27 Noryl—Chapter 18 Ultem—Chapter 35 Goodyear Natsyn—Chapter 75 Honeywell Aclar—Chapter 13 Japan Synthetic Rubber Company JSR BR—Chapter 74

454

The Effects of UV Light and Weather on Plastics and Elastomers

Laporte AlphaGary Evoprene—Chapter 65 LNP Engineering Plastics General Purpose Polystyrene—Chapter 45 Nylon 6/6—Chapter 22 Nylon 6—Chapter 20 Polycarbonate—Chapter 27 Polyethylene—Chapter 37 Polypropylene—Chapter 42 Polysulfone—Chapter 47 Lucite Tufcoat—Chapter 6 Mitsubishi Iupital—Chapter 3 Rayon—Chapter 4 Reny—Chapter 25 Mitsui Chemicals TPX—Chapter 43 NOVA Chemicals Styrosun—Chapter 46 Novacor NAS—Chapter 5 Zylar—Chapter 5 Novamont Mater-Bi—Chapter 57 Novatec Kydex—Chapter 54 Novaloy—Chapter 53 Noveon Estane—Chapter 66 Polimeri Dutral—Chapter 71 PolyOne Forprene—Chapter 62 Geon—Chapter 51

Recticel Colo-Fast—Chapter 59, 76 Shell Chemical Kraton—Chapter 65 Solvay Advanced Polymers IXEF—Chapter 26 Torlon—Chapter 34 Solvay Plastics Udel—Chapter 47 Solvay Solexis Halar—Chapter 12, 14 Hylar—Chapter 12 Solef—Chapter 12 Ticona Celanex—Chapter 29 Celcon—Chapter 3 GUR—Chapter 40 Hostaform—Chapter 3 Vectra—Chapter 31 Ube Nylon 6—Chapter 20 Upilex—Chapter 33 Upimol—Chapter 33 United Coatings Elastuff—Chapter 76 Victrex Victrex PEEK—Chapter 36 Westlake Ardel—Chapter 32

Plastics Design Library Founding Editor: William A. Woishnis

Fluorinated Coatings and Finishes Handbook: The Definitive User’s Guide and Databook, Laurence W. McKeen, 978-0-8155-1522-7, 400 pp., 2006 Fluoroelastomers Handbook: The Definitive User’s Guide and Databook, Albert L. Moore, 0-81551517-0, 359 pp., 2006 Reactive Polymers Fundamentals and Applications: A Concise Guide to Industrial Polymers, J.K. Fink, 0-8155-1515-4, 800 pp., 2005 Fluoropolymers Applications in Chemical Processing Industries, P. R. Khaladkar, and S. Ebnesajjad, 0-8155-1502-2, 592 pp., 2005 The Effect of Sterilization Methods on Plastics and Elastomers, 2nd Ed., L. K. Massey, 0-8155-15057, 408 pp., 2005 Extrusion: The Definitive Processing Guide and Handbook, H. F. Giles, Jr., J. R. Wagner, Jr., and E. M. Mount, III, 0-8155-1473-5, 572 pp., 2005 Film Properties of Plastics and Elastomers, 2nd Ed., L. K. Massey, 1-884207-94-4, 250 pp., 2004 Handbook of Molded Part Shrinkage and Warpage, J. Fischer, 1-884207-72-3, 244 pp., 2003 Fluoroplastics, Volume 2: Melt-Processible Fluoroplastics, S. Ebnesajjad, 1-884207-96-0, 448 pp., 2002 Permeability Properties of Plastics and Elastomers, 2nd Ed., L. K. Massey, 1-884207-97-9, 550 pp., 2002 Rotational Molding Technology, R. J. Crawford and J. L. Throne, 1-884207-85-5, 450 pp., 2002 Specialized Molding Techniques & Application, Design, Materials and Processing, H. P. Heim, and H. Potente, 1-884207-91-X, 350 pp., 2002 Chemical Resistance CD-ROM, 3rd Ed., Plastics Design Library Staff, 1-884207-90-1, 2001

Plastics Failure Analysis and Prevention, J. Moalli, 1-884207-92-8, 400 pp., 2001 Fluoroplastics, Volume 1: Non-Melt Processible Fluoroplastics, S. Ebnesajjad, 1-884207-84-7, 365 pp., 2000 Coloring Technology for Plastics, R. M. Harris, 1884207-78-2, 333 pp., 1999 Conductive Polymers and Plastics in Industrial Applications, L. M. Rupprecht, 1-884207-77-4, 302 pp., 1999 Imaging and Image Analysis Applications for Plastics, B. Pourdeyhimi, 1-884207-81-2, 398 pp., 1999 Metallocene Technology in Commercial Applications, G. M. Benedikt, 1-884207-76-6, 325 pp., 1999 Weathering of Plastics, G. Wypych, 1-884207-75-8, 325 pp., 1999 Dynamic Mechanical Analysis for Plastics Engineering, M. Sepe, 1-884207-64-2, 230 pp., 1998 Medical Plastics: Degradation Resistance and Failure Analysis, R. C. Portnoy, 1-884207-60-X, 215 pp., 1998 Metallocene Catalyzed Polymers, G. M. Benedikt and B. L. Goodall, 1-884207-59-6, 400 pp., 1998 Polypropylene: The Definitive User’s Guide and Databook, C. Maier and T. Calafut, 1-884207-588, 425 pp., 1998 Handbook of Plastics Joining, Plastics Design Library Staff, 1-884207-17-0, 600 pp., 1997 Fatigue and Tribological Properties of Plastics and Elastomers, Plastics Design Library Staff, 1-884207-15-4, 595 pp., 1995 Chemical Resistance, Vol. 1, Plastics Design Library Staff, 1-884207-12-X, 1100 pp., 1994

456

The Effects of UV Light and Weather on Plastics and Elastomers

Chemical Resistance, Vol. 2, Plastics Design Library Staff, 1-884207-13-8, 977 pp., 1994 The Effect of UV Light and Weather on Plastics and Elastomers, 1st Ed., Plastics Design Library Staff, 1-884207-11-1, 481 pp., 1994 The Effect of Creep and Other Time Related Factors on Plastics and Elastomers, Plastics Design Library Staff, 1-884207-03-0, 528 pp., 1991

The Effect of Temperature and Other Factors on Plastics, Plastics Design Library Staff, 1-88420706-5, 420 pp., 1991