Supported in part by the Ministry of Education, Science, Sports and Culture under Grant-in-Aid for Publication of Scientific Research Result.

Transcription

1 NMR SPECTROSCOPY AND STEREOREGULARITY OF POLYMERS NMR SPECTROSCOPY AND STEREORHULARITY OF POLYMERS Kei Matsuzaki, Toshiyuki Uryu, and Tetsuo Asakura with 148 Figures and 80 Tables JAPAN SCIENTIFIC SOCIETIES PRESS Tokyo KARGER Basel Freiburg Paris London New York New Delhi- Bangkok Singapore Tokyo Sydney Japan Scientific Societies Press, 1996 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Supported in part by the Ministry of Education, Science, Sports and Culture under Grant-in-Aid for Publication of Scientific Research Result. Published jointly by: Japan Scientific Societies Press 2-10 Hongo, 6-chome, Bunkyo-ku, Tokyo 113, Japan ISBN and S. Karger AG P.O. Box, CH-4009 Basel, Switzerland

2 ISBN Sole distribution rights outside Japan granted to S. Karger AG, Basel. Printed in Japan Preface NMR spectroscopy is now an indispensable tool for use in investigations in the polymer field. Without this technique, detailed characterization of polymer structure, and elucidation of the mechanism of polymerization, polymer reactions and polymer dynamics would not be possible. Since those characteristics are intimately related with the industrial properties of polymers, NMR spectroscopy is invaluable in ongoing developmental research on, e.g., steric and sequence control of polymer structure, and providing polymers with special functionality. Application of NMR spectroscopy to polymers was begun in the early 1960s by Dr. Frank A. Bovey of Bell Telephone Laboratories, and taken up a little later by Dr. Atsuo Nishioka of Electrical Communication Laboratory, Nippon Telegraph and Telephone Public Corp. We recognized its importance in research on polymers and started our investigations just after the publication of their papers, even though we had no equipment. Happily, we obtained our own equipment soon thereafter and were able to extend our investigations. This book summarizes our investigations on polymer structure and polymerization mechanism, together with other related papers in this area, and covers almost all homopolymers. (We asked Professor Tetsuo Asakura to write the chapter on polyolefins.) Methods of characterizing polymer structure and polymerization mechanism by NMR spectroscopy are systematized and the relation between polymer structure and polymerization conditions is elucidated. Reactions related to the microstructure of polymers and the structure of living polymers using both NMR spectroscopy and quantum chemical calculations are included to provide an insight into the polymerization mechanism. vi The book is a comprehensive review of the use of NMR spectroscopy in polymer research and offers the reader suggestions for new applications in the future. The volume does not cover NMR spectroscopy of copolymers, solid state NMR or relaxation phenomena related to polymer dynamics. Each of

3 those is itself a broad field of research and requires a detailed book of its own. We wish to thank the research assistants and the many undergraduate and graduate students who worked hard with us, as well as the many investigators who generously gave us their advice directly at meetings and symposiums, or indirectly through the literature. Thanks are also due to Mr. Tokiji Kawamura (Faculty of Engineering, University of Tokyo), who measured NMR spectra with a 400 MHz apparatus; Professor Naoki Toshima (Faculty of Engineering, University of Tokyo), who gave us the opportunity to revise NMR data; Mr. Kohsaku Okuyama (Institute of Industrial Science, University of Tokyo) who prepared samples of poly- (methyl vinyl ether); Mr. Hisayuki Morii (National Institute of Bioscience and Human Technology, Tsukuba) who assisted us in preparing Sections 1.8,5.5and 18; and Professor Hisaya Sato and Dr. Kenji Ogino (Faculty of Technology, Tokyo University of Agriculture and Technology) who gave us samples of polybutadiene and polyisoprene. We are particularly grateful to Professor Conrad Schuerch, College of Environmental Science and Forestry, State University of New York, who reviewed the entire manuscript and gave us good advice on many problems. We were greatly aided by the books on NMR spectroscopy by Dr. Frank A. Bovey, Nuclear Magnetic Resonance Spectroscopy (Academic Press, 1969), and Chain Structure and Conformation of Macromolecules (Academic Press, 1982). We are also indebted to Professor Atsuo Nishioka (Professor Emeritus, Tokyo Institute of Technology) and Professor Yuzuru Fujiwara (Tsukuba University) for their encouragement and for permission to use a 13C NMR data base (PCMRDB, Polymer 13C NMR Data Base). Publication of this book was supported in part by the Ministry of Education, Science, Sports and Culture of Japan to whom the authors are grateful. September 1995 KeiMatsuzaki Toshiyuki Uryu Contents PREFACE V

4 ACKNOWLEDGEMENTS XV ABBREVIATIONS XVi. I.NMR Spectroscopy and Stereoregularity of Vinyl Polymers and Poly(alkylene oxide)s Chapter 1 Introduction 2 1.1Configuration of Polymers H NMR Spectra of Vinyl Polymers 9 1.3Deuteration of Monomers and Polymers Opening Mode of Vinyl Double Bonds and Ditactic Polymers Model Compounds C NMR Spectra of Vinyl Polymers C Side-Band Spectra Conformation of Vinyl Polymers Rate Processes Observed with NMR Spectroscopy21 Chapter 2 Polyolefins Polyethylene 25 viii 2.2Polypropylene Poly(1-butene) Poly(l-pentene), Poly(l-hexene), Poly(l-heptene), Poly(loctene) and Poly(l-nonene) Poly(3-methyl-l-butene) 38 Chapter 3 Polydienes Polybutadiene Polyisoprene Polychloroprene 51 Chapter 4 Poly(methyl methacrylate) and Related Ester Derivatives Synthesis of Stereoregular Polymethacrylates 57

5 4.21H and 13C NMR Spectroscopy of Poly(methyl methacrylate) Stereoregularity of Related Ester Derivatives Polymerization of Optically Active Monomers and the Stereoregularity of Polymers Two Phase Polymerization of Poly(methyl methacrylate); Polymerization with Grignard Reagent as Catalyst Stereoregularity of Poly(methyl methacrylate) Obtained in Matrix Polymerization Optically Active Derivatives with Helical Structure 74 Chapter 5 Poly(methyl acrylate) and Related Ester Derivatives Synthesis of Stereoregular Poly acrylates Stereoregularity of Polyacrylates Determined by 1H NMR Spectroscopy C NMR Spectroscopy of Polyacrylates Double Bond Opening Mode of Acrylates in Polymerization Asymmetric Effects of Optically Active Side Groups in the Polymerization of Optically Active Acrylates 88 Contentsix 5.6Conformation of Poly(methyl acrylate) 89 Chapter 6Poly(-chloroacrylate)s Introduction Synthesis of Stereoregular Poly(-chloroacrylate)s H NMR Spectroscopy of Poly(-chloroacrylate)s Stereocomplex Formation of Poly(-chloroacrylate)s 97 Chapter 7Poly(vinyl ether)s Introduction Synthesis of Stereoregular Poly(vinyl ether)s H NMR Spectroscopy of Poly(vinyl ether)s C NMR Spectroscopy of Poly(vinyl ether)s Stereochemistry in the Cationic Polymerization of Vinyl Ethers 103

6 7.6Optically Active Copolymers of Poly(vinyl ether)s 108 Chapter 8Poly(-methyl vinyl ether)s 113 Chapter 9PoIy(vinyl ketone)s and Poly(isopropenyl ketone)s H and 13C NMR Spectroscopy of Poly(vinyl ketone)s C NMR Spectroscopy of Poly(isopropenyl ketone)s 120 Chapter 10 Polyacrylonitrile Synthesis of Polyacrylonitrile H NMR Spectroscopy of Polyacrylonitrile C NMR Spectroscopy of Polyacrylonitrile 128 Chapter 11 Polymethacrylonitrile Synthesis of Polymethacrylonitrile 131 X H NMR Spectroscopy and Stereoregularity of Polymethacrylonitrile C NMR Spectroscopy of Polymethacrylonitrile 132 Chapter 12 Polystyrene and Its Derivatives Synthesis of Stereoregular Polystyrene H NMR Spectroscopy of Polystyrene C NMR Spectroscopy of Polystyrene Stereoregularity of Polystyrenes Obtained by Anionic Polymerization Stereoregularity of Polystyrenes Obtained with Butyllithium-Water Stereoregularity of Polystyrenes Obtained with Alfin Catalyst Stereoregularity of Polystyrenes Obtained with Cationic Catalysts Stereoregularity of Polystyrenes Obtained by Radiation-Induced Polymerization Synthesis and Stereoregularity of Poly(methylstyrene)s

7 Synthesis and Stereoregularity of Poly(methoxystyrene)s 152 Chapter 13 Poly(-methylstyrene) Synthesis of Poly(-methylstyrene) H NMR Spectroscopy of Poly(-methylstyrene) C NMR Spectroscopy of Poly(-methylstyrene) Stereoregularity of Pol y(-methylstyrene) Obtained with Anionic Catalysts Stereoregularity of Poly(-methylstyrene) Prepared with Cationic Catalysts 161 Chapter 14 Poly(vinylpyridine)s Synthesis of Poly(vinylpyridine)s H and 13C NMR Spectroscopy of Poly(vinylpyridine)s.163 Contents xi 14.3Mechanism of Isotactic Polymerization of Poly(2- vinylpyridine) 168 Chapter 15 Poly(N-vinylcarbazole) Synthesis of Poly(N-vinylcarbazole) H and 13C NMR Spectroscopy of Poly(N-vinylcarbazole) The Structure of Poly(N-vinylcarbazole) Obtained with Electron Acceptors as Catalysts 175 Chapter 16 Poly(vinyl acetate) Synthesis of Poly(vinyl acetate) H and 13C NMR Spectroscopy of Poly(vinyl acetate) 179 Chapter 17 Poly(isopropenyl acetate) Synthesisof Poly(isopropenyl acetate) H and 13C NMR Spectroscopy of Poly(isopropenyl acetate) 182

8 Chapter18 Poly(ethylene oxide) Synthesisof Poly(ethylene oxide) Conformation of Poly (ethylene oxide) Determined by 1H NMR spectroscopy Opening Mode in the Polymerization of Ethylene Oxide 193 Chapter 19 Poly(propylene oxide) Synthesisof Poly(propylene oxide) NMR Spectroscopy and Stereoregularity of Poly (propylene oxide) 199 xii Chapter 20 Poly(propenyl ether)s Introduction H and 13C NMR Spectroscopy of Poly( -substituted vinyl ether)s Stereochemistry in the Process of Polymerization.206 Chapter 21 Poly(vinyl alcohol) Synthesis of Poly (vinyl alcohol) H and 13C NMR Spectroscopy of Poly(vinyl alcohol).212 Chapter 22 Poly (vinyl chloride) Synthesis of Poly(vinyl chloride) H and 13C NMR Spectroscopy of Poly(vinyl chloride).216 Chapter 23 Factors Affecting Stereoregularity of Vinyl Polymers Radical Polymerization Cationic Polymerization Anionic Polymerization 225

9 II.Reactions Correlated to the Stereoregularity of Polymers Chapter 24 Thermal Reaction and Hydrolysis of Polymethacrylates and Polyacrylates Thermal Reaction and Anhydride Formation of Polymethacrylates Hydrolysis and Anhydride Formation of Polymethacrylates Hydrolysis and Anhydride Formation of Polyacrylates231 Contents xiii Chapter 25 Thermal Reaction of Poly(methyl vinyl ketone) and Poly(isopropenyl methyl ketone) Thermal Reaction of Poly(methyl vinyl ketone) Thermal Reaction of Poly(isopropenyl methyl ketone).235 Chapter 26 Racemization of Polyacrylonitrile 239 III.NMR Spectroscopy of Living Polymers and Quantum Chemical Analysis Chapter 27 Living Polystyrene NMR Spectroscopy of Polystyryl Anions and Their Model Compounds NMR Spectroscopy of Polystyryllithium and Its Model Compounds NMR Spectroscopy of Polystyrylpotassium and Its Model Compounds Effect of Counter Cation on the Excess Charge Distribution Effect of the Kind of Solvent on the Excess Charge Distribution Rotation of C-Cl Bond of Polystyryllithium and Its Model Compounds Quantum Chemical Treatment of Polystyryl Anions Spin-Lattice Relaxation Times T1) of Living Anion 251 Chapter 28 Living Poly(-methylstyrene) 253

10 28.1 1H and 13C NMR Spectroscopy of Living Poly(- methylstyrene) Quantum Chemical Calculation of Poly(-methylstyryl) Anion Rotation of C-C 1 Bond of Poly (-methylstyryl) Lithium 257 xiv Chapter 29 Living Poly(methylstyrene)s Introduction NMR Spectroscopy of Living Poly(o-methylstyrene) and Its Model Compound NMR Spectroscopy of Living Poly(m-methylstyrene) and Its Model Compound NMR Spectroscopy of Living Poly(p-methylstyrene) 263 Chapter 30 Living Poly(o-methoxystyrene) 265 0UBJECT INDEX 269 ABOUT THE AUTHORS 277 Acknowledgements We are grateful to the copyright owners of the following journals for kind permission to reproduce the figures listed below. Academic Press, Ltd. (Annual Reports on NMR Spectroscopy) Fig. 2-2 American Chemical Society (Macromolecules) Figs. 2-4, 2-7, and 2-9 Butterworth-Heinemann journals, Elsevier Science Ltd.(Polymer and Polymer Communication, Figs. 2-3, 2-8, and 2-10) John Wiley & Sons, Inc. (Journal of Polymer Science) Figs. 1-4,4-5, 5-1, 5-2, 6-1,7-4,7-5,8-1, 8-2, 8-3, 8-4, 10-1,10-2,10-3,10-4,10-5,11-2,11-3, 11-4, 12-1, 12-5, 14-1, 14-2, 14-3, 14-4, 14-5, 14-6, 14-7, 14-8, 14-9, 14-10, 17-1,17-2, 17-3,18-2,18-6,18-7,19-1, 20-1,20-2, 22-1,22-2, 23-1, 24-1, 24-2, and 24-3

11 Marcel Dekker Inc. (Journal of Macromolecular Science) Fig. 2-1 The Royal Society of Chemistry (Quaternary Review) Fig. 1-2 The Society of Polymer Science, Japan (Polymer Journal) Figs. 2-5 and 2-6 Verlag Helvetica Chimica Acta AG (Helvetica Chimica Acta) Fig. 9-1 Hüthig & Wepf Verlag (Makromolekulare Chemie and Macromolecular Chemistry and Physics) Figs. 4-2,4-3,4-4,4-6, 5-7,5-8, 5-10,7-1,7-2, 7-3,7-6,7-7,7-8,7-9,9-2,9-3,9-4, 11-1,12-3,12-4, 12-6,12-7,12-8, 12-9, 12-10, 12-11, 12-12, 15-1, 15-2, 15-3, 20-3, 20-4, 20-5, 22-3, 25-1,25-2, 25-3,25-4,27-1,27-2,27-3,27-4,27-5,27-6,28-1,28-2,28-3,28-4,28-5, 29-1, 29-2, 29-3, 29-4, 29-5, 30-1, and Schemes I and II in Chapter 20 Abbreviations The following abbreviations are often utilized: AIBNAzobisisobutyronitrile BuLin-Butyllithium BPOBenzoyl peroxide DEEDiethyl ether DMFDimethylformamide DMSODimethyl sulfoxide DPDegree of polymerization GPCGel permeation chromatography MEKMethyl ethyl ketone MnNumber average molecular weight MwWeight average molecular weight MWDMolecular weight distribution NBSN-Bromosuccinimide PAMSTPoly(-methylstyrene) PANPolyacrylonitrile PBDPolybutadiene PCPPolychloroprene PEOPoly(ethylene oxide), Poly(oxy ethylene) PhMgBrPhenylmagnesium bromide

12 PIPPolyisoprene PMAPoly(methyl acrylate) PMANPolymethacrylonitrile PMMAPoly(methyl methacrylate) PMVEPoly(methyl vinyl ether) PMVKPoly(methyl vinyl ketone) Abbreviations xvii PPOPoly(propylene oxide) PSPolystyrene PVAPoly (vinylalcohol) PVACPoly (vinylacetate) PVCPoly(vinylchloride) PVCZPoly (vinylcarbazole) RISRotationalisomeric state THFTetrahydrofuran THPTetrahydropyran TLCThin layer chromatography 1H and 13C NMR Spectra: 1H and 13C NMR spectra cited in this book were determined with a JEOL PS-100 spectrometer, that is, 100 MHz for 1H and 25 MHz for 13C nuclei, unless otherwise stated.