NMR SPECTROSCOPY AND STEREOREGULARITY OF POLYMERS

Transcription

1 NMR SPECTROSCOPY AND STEREOREGULARITY OF POLYMERS

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3 NMR SPECTROSCOPY AND STEREOREGULARITY OF POLYMERS Kei Matsuzaki, Toshiyuki Uryu, and Tetsuo Asakura r with 148 Figures and 80 Tables JAPAN SCIENTIFIC SOCIETIES PRESS Tokyo KAR.GER. Basel Freiburg Paris London New York New Delhi Bangkok Singapore Tokyo Sydney

4 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 ISBN Sole distribution rights outside Japan granted to S. KARGER AG, Basel. Printed in Japan

5 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.

6 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 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 1.8,5.5 and 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 l3c NMR data base (PCMRDB, Polymer l3c 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 Kei Matsuzaki Toshiyuki Uryu

7 Contents PREFACE.... ACKNOWLEDGEMENTS ABBREVIATIONS v xv xvi I. NMR SPECTROSCOPY AND STEREOREGULARITY OF VINYL POLYMERS AND POLY(ALKYLENE OXIDE)S Chapter 1 Introduction Configuration of Polymers lh NMR Spectra of Vinyl Polymers Deuteration of Monomers and Polymers Opening Mode of Vinyl Double Bonds and Ditactic Polymers Model Compounds i3c NMR Spectra of Vinyl Polymers i3c Side-Band Spectra Conformation of Vinyl Polymers Rate Processes Observed with NMR Spectroscopy 21 Chapter 2 Polyolefins Polyethylene. 25

8 viii 2.2 Polypropylene Poly(l-butene) Poly(l-pentene), Poly(l-hexene), Poly(l-heptene), Poly(loctene) and Po1y(l-nonene) Poly(3-methyl-1-butene) Chapter 3 Polydienes Polybutadiene Polyisoprene Polychloroprene. 51 Chapter 4 Poly(methyl methacrylate) and Related Ester Derivatives Synthesis of Stereoregular Polymethacrylates IH and l3c 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 Chapter 5 Poly(methyl acrylate) and Related Ester Derivatives Synthesis of Stereoregular Polyacrylates Stereoregularity of Polyacrylates Determined by IH NMR Spectroscopy l3c 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

9 Contents ix 5.6 Conformation of Poly(methyl acrylate) Chapter 6 Poly(a-chloroacrylate)s Introduction Synthesis of Stereoregular Poly(a-chloroacrylate)s lh NMR Spectroscopy of Poly(a-chloroacrylate)s Stereocomplex Formation of Poly( a-chloroacrylate)s. 97 Chapter 7 Poly( vinyl ether)s Introduction Synthesis of Stereoregular Poly(vinyl ether)s lh NMR Spectroscopy of Poly(vinyl ether)s C NMR Spectroscopy ofpoly(vinyl ether)s Stereochemistry in the Cationic Polymerization of Vinyl Ethers Optically Active Copolymers of Poly(vinyl ether)s Chapter 8 Po1y(a-methyl vinyl ether)s Chapter 9 Poly(vinyl ketone)s and Poly(isopropenyl ketone)s 9.1 lh and 13C NMR Spectroscopy ofpoly(vinyl ketone)s C NMR Spectroscopy ofpoly(isopropenyl ketone)s Chapter 10 Polyacrylonitrile Synthesis of Polyacrylonitrile 10.2 lh NMR Spectroscopy of Poly acrylonitrile C NMR Spectroscopy of Poly acrylonitrile Chapter 11 Polymethacrylonitrile Synthesis of Polymethacrylonitrile

10 x 11.2 lh NMR Spectroscopy and Stereoregularity of Polymethacrylonitrile l3c NMR Spectroscopy of Polymethacrylonitrile Chapter 12 Polystyrene and Its Derivatives Synthesis of Stereoregular Polystyrene lh NMR Spectroscopy of Polystyrene l3c 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 Synthesis and Stereoregularity of Poly(methoxystyrene)s 152 Chapter 13 Poly( a-methylstyrene) Synthesis ofpoly(a-methylstyrene) lh NMR Spectroscopy ofpoly(a-methylstyrene) l3c NMR Spectroscopy ofpoly(a-methylstyrene) Stereoregularity of Poly(a-methylstyrene) Obtained with Anionic Catalysts Stereoregularity of Poly(a-methylstyrene) Prepared with Cationic Catalysts Chapter 14 Poly(vinylpyridine)s Synthesis ofpoly(vinylpyridine)s lh and i3c NMR Spectroscopy of Poly(vinylpyridine)s 163

11 Contents 14.3 Mechanism of Isotactic Polymerization of Poly(2- vinylpyridine).... Xl 168 Chapter 15 Poly(N-vinylcarbazole) Synthesis of Poly(N-viny1carbazole) 15.2 IH and i3c NMR Spectroscopy of Poly(N-viny1carbazole) 15.3 The Structure of Poly(N-viny1carbazole) Obtained with Electron Acceptors as Catalysts Chapter 16 Poly(vinyl acetate) Synthesis of Po 1 y(vinyl acetate) 16.2 IH and i3c NMR Spectroscopy of Poly(vinyl acetate) Chapter 17 Po1y(isopropenyl acetate) Synthesis of Po 1 y(isopropenyl acetate) 17.2 IH and i3c NMR Spectroscopy of Poly(isopropenyl acetate) Chapter 18 Poly( ethylene oxide) Synthesis of Poly( ethylene oxide) Conformation of Poly(ethylene oxide) Determined by IH NMR spectroscopy Opening Mode in the Polymerization of Ethylene Oxide 193 Chapter 19 Poly(propylene oxide) Synthesis ofpoly(propylene oxide) NMR Spectroscopy and Stereoregularity of Poly(propylene oxide)

12 xii Chapter 20 Poly(propenyl ether)s Introduction IH and l3c NMR Spectroscopy of Poly(f3-substituted vinyl ether)s Stereochemistry in the Process of Polymerization Chapter 21 Poly(vinyl alcohol) Synthesis ofpoly(vinyl alcohol) IH and l3c NMR Spectroscopy of Poly(vinyl alcohol) 212 Chapter 22 Poly( vinyl chloride) Synthesis ofpoly(vinyl chloride) IH and l3c NMR Spectroscopy ofpoly(vinyl chloride) 216 Chapter 23 Factors Affecting Stereoregularity of Vinyl Polymers Radical Polymerization 23.2 Cationic Polymerization Anionic Polymerization II. REACTIONS CORRELATED TO THE STEREOREGULARITY OF POLYMERS Chapter 24 Thermal Reaction and Hydrolysis ofpolymethacrylates and Polyacrylates Thermal Reaction and Anhydride Formation of Polymethacrylates Hydrolysis and Anhydride Formation of Polymethacrylates 24.3 Hydrolysis and Anhydride Formation of Polyacrylates

13 Contents xiii Chapter 25 Thermal Reaction ofpoly(methyl vinyl ketone) and Poly(isopropenyl methyl ketone) Thennal Reaction ofpoly(methyl vinyl ketone) Thennal Reaction ofpoly(isopropenyl methyl ketone) 235 Chapter 26 Racemization of Polyacrylonitrile 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 27.5 Effect of the Kind of Solvent on the Excess Charge Distribution Rotation of Ca-Cl Bond of Polystyryllithium and Its Model Compounds Quantum Chemical Treatment of Polystyryl Anions 27.8 Spin-Lattice Relaxation Times TI of Living Anion Chapter 28 Living Poly( a-methylstyrene) IH and 13C NMR Spectroscopy of Living Poly(amethyl styrene) Quantum Chemical Calculation of Poly(a-methylstyryl) Anion Rotation of Ca-C 1 Bond of Poly (a-methylstyryl) Lithium 257

14 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) Chapter 30 Living Poly(o-methoxystyrene) SUBJECT INDEX ABOUT THE AUTHORS

15 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 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 Htithig & 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

16 Abbreviations The following abbreviations are often utilized: AIBN BuLi BPO DEE DMF DMSO DP GPC MEK MN Mw MWD NBS PAMST PAN PBD PCP PEO PhMgBr PIP PMA PMAN PMMA PMVE PMVK Azobisisobutyronitrile n-butyllithium Benzoyl peroxide Diethyl ether Dimethylformamide Dimethyl sulfoxide Degree of polymerization Gel permeation chromatography Methyl ethyl ketone Number average molecular weight Weight average molecular weight Molecular weight distribution N -Bromosuccinimide Poly( a-methyl styrene ) Polyacrylonitrile Polybutadiene Polychloroprene Poly(ethylene oxide), Poly(oxy ethylene) Phenylmagnesium bromide Polyisoprene Poly(methyl acrylate) Polymethacrylonitrile Poly(methyl methacrylate) Poly(methyl vinyl ether) Poly(methyl vinyl ketone)

17 Abbreviations xvii PPO PS PYA PVAC PVC PVCZ RIS THF THP TLC Poly(propylene oxide) Polystyrene Poly(vinyl alcohol) Poly(vinyl acetate) Poly(vinyl chloride) Poly(vinyl carbazole) Rotational isomeric state Tetrahydrofuran Tetrahydropyran Thin layer chromatography IH and l3c NMR Spectra: IH and l3c NMR spectra cited in this book were determined with a JEOL PS-100 spectrometer, that is, 100 MHz for IH and 25 MHz for l3c nuclei, unless otherwise stated.

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