Structure and Properties of Oriented Polymers

Structure and Properties of Oriented Polymers

Structure and Properties of Oriented Polymers Edited by 1. M. Ward IRC in Polymer Science and Technology Universities of Leeds, Bradford and Durham UK I uni SPRlNGER-SCIENCE+BUSINESS MEDIA, B.V.

First edition 1975 Second edition 1991 1991Springcr sat:nce+busincss Media Dordrccht Originally publishcd by Chapman & Hali in 1915, 1991 Softcover reprint of the hardcover 2nd edition 1991 Typeset in 10/12 Palatino by Scientific Publishing Services (P) Ud., Chennai, India ISBN 978-94-010-6469-9 ISBN 978-94-011-5844-2 (ebook) DOI 10.1007/978-94-011-5844-2 Apart from any iair dealing for the purposes of research or private study, ar criticism or review, as permitted under the UK Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored, or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries conceming reproduction outside the terms stated here should be sent to the publishers at the London address printed on this page. The publisher makes no representation, express ar implied, with regard ta the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. A catalogue record for this book is available from the 8ritish Library Printed on permanent acid-free text paper, manufactured in accordance with ANSI/NISO Z39.48-1992 and ANSI/NISO Z39.48-1984 (Permanence of Paper).

Contents List of contributors Preface 1 Introduction I. M. Ward 1.1 The phenomenon of orientation 1.2 General effects of orientation and anisotropy 1.3 Some structural features of polymers 1.4 Achieving orientation 1.5 Orientation and its relationship to anisotropy 2 Physicochemical approaches to the measurement of molecular anisotropy G. L. Wilkes and RS. Stein 2.1 Optical techniques 2.2 Wide-angle X-ray diffraction 2.3 Orientation function diagrams 2.4 Linear dichroism 2.5 Sonic velocity 2.6 Scattering of light and small-angle X-rays 2.7 Comparison of the different methods 2.8 Closing remarks 3 Structure and morphology of oriented polymers P. J. Barham 3.1 Introduction ix xi 1 1 4 6 18 24 41 44 44 59 70 72 77 82 129 134 135 142 142

VI Contents 3.2 Rigid polymeric fibres 3.3 Flexible polymeric fibres 4 Infrared dichroism, polarized fluorescence and Raman spectroscopy D. I. Bower 4.1 Introduction 4.2 Theory 4.3 Experimental work 4.4 Summary 5 Nuclear magnetic resonance H. W. Spiess 5.1 Introduction 5.2 Solid-state NMR 5.3 NMR line shapes of oriented polymers 5.4 Experimental examples 5.5 Summary 6 Mechanical anisotropy at small strains D. W. Hadley and I. M.Ward 6.1 Introduction 6.2 Anisotropic mechanical behaviour 6.3 Theoretical calculation of elastic constants 6.4 Mechanical measurement of elastic constants 6.5 Interpretation of anisotropic mechanical behaviour 6.6 Models for ultrahigh modulus polyethylene 6.7 Modern wave propagation methods 6.8 Conclusion 7 Anisotropic creep behaviour M. W. Darlington 7.1 Introduction 7.2 Theoretical background 7.3 Experimental methods 7.4 Problems of data presentation 7.5 Utility of elasticity theory 7.6 Anisotropic creep in semicrystalline polymers 144 147 178 181 181 186 204 231 231 234 234 234 240 251 266 266 269 269 270 273 289 290 307 314 332 333 338 338 339 344 351 353 357

Contents VII 7.7 Anisotropic creep in amorphous thermoplastics 7.8 General conclusions 8 Anisotropic yield behaviour R. A. Duckett 8.1 Preliminary definitions 8.2 The phenomenology of yield 8.3 Structural changes resulting from plastic strain 8.4 The nature of the yield point 8.5 General discussion and conclusions 9 Film formation P. J. Mills 9.1 Introduction 9.2 General principles of film formation 9.3 Film forming processes 9.4 Summary Acknowledgements 10 Liquid crystalline polymers J. E. McIntyre 10.1 Introduction 10.2 Classification of liquid crystalline polymers 10.3 Chemical structures 10.4 Rheological behaviour 10.5 Fibres from lyotropic systems 10.6 Thermotropic polymers 10.7 Blends 10.8 Metastable and transient mesophases 10.9 End uses Acknowledgements Index 370 373 374 377 377 380 396 408 416 419 423 423 424 427 445 445 446 447 447 448 450 460 462 483 500 504 507 509 509 515

Contributors P. J. Barham University of Bristol H.H. Wills Physics Laboratory Royal Fort Tyndall Avenue Bristol BS8 1 TL D.1. Bower Department of Physics and Astronomy University of Leeds Leeds LS2 9JT M. W. Darlington School of Industrial and Manufacturing Science Cranfield University Cranfield Bedford MK43 OAL R. A. Duckett IRC in Polymer Science and Technology University of Leeds Leeds LS2 9JT D. W. Hadley Department of Physics University of Reading Reading RG6 6AF J. E. McIntyre Department of Textile Industries University of Leeds Leeds LS2 9JT P. J. Mills ICI Materials Centre PO Box 90 Wilton Middlesbrough TS6 8JE D. W. Saunders 98 Topcliffe Road Thirsk N. Yorkshire 407 IRY. H. W. Spiess Max-Planck Institut fur Polymerforschung Postfach 3148 D-55021 Mainz Germany

X Contributors R. S. Stein Polymer Research Institute Lederle Graduate Research Centre and University of Massachusetts Amherst MA 01003 United States G. L. Wilkes Polymer Materials Laboratory State University Blacksburg VA 24061 United States I. M. Ward IRC in Polymer Science and Technology University of Leeds Leeds LS2 9JT

Preface The first edition was produced at a time when the advantages of studying oriented polymers were just becoming apparent. From a scientific standpoint it had been demonstrated that greater insight into both structure and properties could be obtained if an oriented polymer was prepared. From a technological viewpoint, major advances were underway, especially in high modulus and high strength fibres. Twenty years later, it is possible to review the scientific advances which have been made in this area and to provide much wider perspectives for the technology. As in the case of the first edition, the emphasis is on the methodologies available for characterizing oriented polymers and their mechanical behaviour. It is a particular pleasure to thank the contributing authors for their cooperation and Dr Philip Hastings of Chapman & Hall for his support and encouragement. I am also indebted to Professors A. H. Windle and D. C. Bassett for their respective contributions to sections 1.3.1 and 1.3.4. Although this chapter has been extensively revised, the contribution of the late Leslie Holliday to the first edition of this book is also acknowledged.