Lecture Notes In Chemistry 82 Wei-Fang Su Principles of Polymer Design and Synthesis Springer
Lecture Notes In Chemistry 82 Principles of Polymer Design and Synthesis Wei-Fang Su
Foreword While the ubiquity of polymers might imply that this field forms a significant portion of undergraduate and graduate courses,students typically leave their studies with only rudimentary knowledge of this important subject.This is perhaps particularly surprising given that many of these new graduates will enter careers in the consumer goods,pharmaceutical,materials,electronics,or other industries where polymers hold the key to the performance of the final product.With this in mind,it is critical that we better prepare our students for their ultimate careers.For this reason,Principles of Polymer Design and Synthesis is a welcome addition to the toolkit for young scientists and engineers,providing a solid base for learning about the incredible influence of polymers to modern life.The logical format of the book and its combination of breadth and depth will also allow it to serve as a very useful text for established professionals who are entering the broad field of polymer chemistry or researchers who want to freshen up their knowledge with some of the latest directions in polymer design and synthesis. The book introduces polymers to chemists,material scientists,and engineers with no prior experience of the area in a straightforward,rigorous,and logical manner. Intended for students who have completed undergraduate courses in organic and physical chemistry,the chapters cover the properties,synthesis,and characterization of polymeric materials.Readers will gain an appreciation for the diversity of poly- mers with examples ranging from natural proteins,rubber,and cellulose to the huge variety of synthetic materials that are used to produce fibers,plastics,and elastomers. The aim is to equip scientists and engineers with a deeper understanding of how the structure of polymers dictates their function and potential applications- whether that may be in cheap polyethylene bags or sophisticated light emitting materials for flexible displays.Not only will readers learn how to synthesize common polymers,they will also gather greater knowledge of the principles for designing materials and an appreciation for the state of the art.The value in Principles of Polymer Design and Synthesis is in giving students and researchers a flavor of the breadth of polymer science and inspiring them to delve deeper into the field and develop materials for the next great advances to impact our lives. Craig J.Hawker
Foreword While the ubiquity of polymers might imply that this field forms a significant portion of undergraduate and graduate courses, students typically leave their studies with only rudimentary knowledge of this important subject. This is perhaps particularly surprising given that many of these new graduates will enter careers in the consumer goods, pharmaceutical, materials, electronics, or other industries where polymers hold the key to the performance of the final product. With this in mind, it is critical that we better prepare our students for their ultimate careers. For this reason, Principles of Polymer Design and Synthesis is a welcome addition to the toolkit for young scientists and engineers, providing a solid base for learning about the incredible influence of polymers to modern life. The logical format of the book and its combination of breadth and depth will also allow it to serve as a very useful text for established professionals who are entering the broad field of polymer chemistry or researchers who want to freshen up their knowledge with some of the latest directions in polymer design and synthesis. The book introduces polymers to chemists, material scientists, and engineers with no prior experience of the area in a straightforward, rigorous, and logical manner. Intended for students who have completed undergraduate courses in organic and physical chemistry, the chapters cover the properties, synthesis, and characterization of polymeric materials. Readers will gain an appreciation for the diversity of polymers with examples ranging from natural proteins, rubber, and cellulose to the huge variety of synthetic materials that are used to produce fibers, plastics, and elastomers. The aim is to equip scientists and engineers with a deeper understanding of how the structure of polymers dictates their function and potential applications— whether that may be in cheap polyethylene bags or sophisticated light emitting materials for flexible displays. Not only will readers learn how to synthesize common polymers, they will also gather greater knowledge of the principles for designing materials and an appreciation for the state of the art. The value in Principles of Polymer Design and Synthesis is in giving students and researchers a flavor of the breadth of polymer science and inspiring them to delve deeper into the field and develop materials for the next great advances to impact our lives. Craig J. Hawker v
Preface Synthetic polymers are vital materials used in modern daily life from packaging, electronics,medical devices,clothing,vehicles,buildings,etc.How can a scientist or engineer synthesize and utilize polymers to solve the problems of daily life? This is the objective of this textbook to provide students with fundamental knowledge in the design and synthesis of polymers to achieve specific properties required in the applications.To have the ability to design a polymer,one has to understand the chemical structure effects on the physical and chemical charac- teristics of polymer first.Therefore,in this book,the first five chapters discuss the properties and characterization of polymers.Then,six chapters are followed to discuss the principles of polymerization reactions including step,radical chain, ionic chain,chain copolymerization,coordination,and ring opening.They cover the descriptions of how commonly known polymers are synthesized. This book is intended as an introductory textbook for one semester course in polymer chemistry or polymer synthesis at the advanced undergraduate or beginning graduate level of students in chemistry,chemical engineering,and material science and engineering with no prior training in polymer.The students who uses this book should have completed undergraduate courses in organic chemistry and physical chemistry.After going through the lectures or reading the text of this book,they will have the capability to synthesize common known polymers and comprehend the advanced polymerization reactions reported in the literature to further design and synthesize new polymers. Finally,I would like to thank the encouragement and patience obtained from my husband Cheng-Hong Su during the course of this work and the inspiration, chemical formula drawing,and proof reading from my students Chun-Chih Ho, Shih-Hsiang Lin,Tzu-Chia Huang,Shang-jung Wu,Shih-Chieh Wang,Jhin-Fong Lin,and Hsueh-Chung Liao.Thanks are also due to typing and organization of the manuscript done by Shiow-Wei Wang and drawing of figures done by Yin-Hsi Lin. vii
Preface Synthetic polymers are vital materials used in modern daily life from packaging, electronics, medical devices, clothing, vehicles, buildings, etc. How can a scientist or engineer synthesize and utilize polymers to solve the problems of daily life? This is the objective of this textbook to provide students with fundamental knowledge in the design and synthesis of polymers to achieve specific properties required in the applications. To have the ability to design a polymer, one has to understand the chemical structure effects on the physical and chemical characteristics of polymer first. Therefore, in this book, the first five chapters discuss the properties and characterization of polymers. Then, six chapters are followed to discuss the principles of polymerization reactions including step, radical chain, ionic chain, chain copolymerization, coordination, and ring opening. They cover the descriptions of how commonly known polymers are synthesized. This book is intended as an introductory textbook for one semester course in polymer chemistry or polymer synthesis at the advanced undergraduate or beginning graduate level of students in chemistry, chemical engineering, and material science and engineering with no prior training in polymer. The students who uses this book should have completed undergraduate courses in organic chemistry and physical chemistry. After going through the lectures or reading the text of this book, they will have the capability to synthesize common known polymers and comprehend the advanced polymerization reactions reported in the literature to further design and synthesize new polymers. Finally, I would like to thank the encouragement and patience obtained from my husband Cheng-Hong Su during the course of this work and the inspiration, chemical formula drawing, and proof reading from my students Chun-Chih Ho, Shih-Hsiang Lin, Tzu-Chia Huang, Shang-jung Wu, Shih-Chieh Wang, Jhin-Fong Lin, and Hsueh-Chung Liao. Thanks are also due to typing and organization of the manuscript done by Shiow-Wei Wang and drawing of figures done by Yin-Hsi Lin. vii
Contents 1 Introduction.......。.. 1 l.1 Types of Polymers.························ 3 l2 Types of Polymerization...·.·············… l.3 Nomenclature of Polymers........·············· 4 l.4 Polymer Recycling.····.····················· 7 1.5 7 References...··············· F 2 Polymer Size and Polymer Solutions.,.....,....·.....··. 9 2.1 The Molecular Weight of Polymer.................... 9 2.2 Polymer Solutions...............·.·.···· 12 2.3 Measurement of Molecular Weight.················· 16 2.4 Problems..·.…。···…······ 24 References...................。····· 25 3 Structure Morphology Flow of Polymer................... 27 3.1 Chemical and Molecular Structure of Polymer............ 27 3.2 Crystal Structure of Homopolymer.....··.·.···.···· 31 3.3 Crystal Structure of Copolymer...................... 33 3.4 Liquid Crystalline Polymer...·..·····.....····· 37 3.5 Crosslinked Polymer.....·· 43 3.6 Polymer Blend.....·..·············· 44 3.7 Polymer Flow Under Shear Force..·.·.,··.·········· 46 3.8 Polymer Flow Under Thermal Stress................... 52 3.9 Problems.····……· 56 References...。..…。.·.·…······· 58 4 Chemical and Physical Properties of Polymers··.··..··.···· 61 4.1 Chemical Property of Polymer....................... 61 4.2 Mechanical Property of Polymer,·..··.··...········· 66 4.3 Thermal Property of Polymer...........······· 68 4.4 Electrical Property of Polymer..........·..·...···.·. 72 年
Contents 1 Introduction ........................................ 1 1.1 Types of Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Types of Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Nomenclature of Polymers. . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.4 Polymer Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.5 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2 Polymer Size and Polymer Solutions ...................... 9 2.1 The Molecular Weight of Polymer . . . . . . . . . . . . . . . . . . . . 9 2.2 Polymer Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 Measurement of Molecular Weight . . . . . . . . . . . . . . . . . . . . 16 2.4 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3 Structure Morphology Flow of Polymer . . . . . . . . . . . . . . . . . . . 27 3.1 Chemical and Molecular Structure of Polymer . . . . . . . . . . . . 27 3.2 Crystal Structure of Homopolymer . . . . . . . . . . . . . . . . . . . . 31 3.3 Crystal Structure of Copolymer . . . . . . . . . . . . . . . . . . . . . . 33 3.4 Liquid Crystalline Polymer . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.5 Crosslinked Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 3.6 Polymer Blend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.7 Polymer Flow Under Shear Force. . . . . . . . . . . . . . . . . . . . . 46 3.8 Polymer Flow Under Thermal Stress. . . . . . . . . . . . . . . . . . . 52 3.9 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4 Chemical and Physical Properties of Polymers . . . . . . . . . . . . . . 61 4.1 Chemical Property of Polymer . . . . . . . . . . . . . . . . . . . . . . . 61 4.2 Mechanical Property of Polymer . . . . . . . . . . . . . . . . . . . . . 66 4.3 Thermal Property of Polymer. . . . . . . . . . . . . . . . . . . . . . . . 68 4.4 Electrical Property of Polymer . . . . . . . . . . . . . . . . . . . . . . . 72 ix
Contents 4.5 Optical Property of Polymer.....·...,.············· 76 4.6 Processability of Polymer.......................... 83 4.7 Problems.····………·…· 86 References...。。。。。。··················· 87 5 Characterization of Polymer......,...,··....·········· 89 5.1 Instruments and Testing Methods for Polymer Characterization........·· 89 5.2 Characterization of Chemical Structures of Polymers....... 90 5.2.1 Chemical Reaction Method................... 90 5.2.2 Infrared Spectroscopy·.·.·.················ 90 5.2.3 Raman Spectroscopy...····················· 92 5.2.4 UV-Visible Spectroscopy.....·.···.·········· 93 5.2.5 Nuclear Magnetic Resonance Spectroscopy.······· 95 5.2.6 Electron Spin Resonance..... 98 5.3 Characterization of Morphology and Physical Structure of Polymer...········· 100 5.3.1 Transmission Electron Microscopy.............. 100 5.3.2X-Ray Scattering................·.··.··· 102 5.3.3 Atomic Force Microscopy.............. 103 5.4 Characterization of Thermal Properties of Polymers 104 5.4.1 Differential Thermal Analysis and Differential Scanning Calorimetry....................... 104 5.4.2 Thermomechanical Analysis 106 5.4.3 Thermogravimetric Analysis...,.··.·········· 107 5.4.4 Flammability Test........................... 108 5.5 Problems.···……· 109 References.....。..····· 110 6 Step Polymerization.......·..··.··········… 111 6.1 Chemical Reactions and Reaction Mechanisms of Step Polymerization.....···.·.················· 111 6.1.1 Carbonyl Addition:Elimination Reaction Mechanism..............··..······ 113 6.1.2 Carbonyl Addition:Substitution Reaction Mechanism........................ 115 6.1.3 Nucleophilic Substitution Reaction Mechanism.···· 116 6.1.4 Double-Bond Addition Reaction Mechanism.·.···· 116 6.1.5 Free-Radical Coupling...................... 117 6.1.6 Aromatic Electrophilic-Substitution Reaction Mechanism........,.·.······.·· 117 6.2 Reaction Kinetics of Step Polymerization,.....·.....··. 117 6.3 Molecular Weight Control in Step Polymerization.···.···· 119 6.4 Molecular Weight Distribution.........··..··..······ 122 6.5 Network Formation from Step Polymerization.....··...·. 124
4.5 Optical Property of Polymer . . . . . . . . . . . . . . . . . . . . . . . . 76 4.6 Processability of Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . 83 4.7 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5 Characterization of Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 5.1 Instruments and Testing Methods for Polymer Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 5.2 Characterization of Chemical Structures of Polymers . . . . . . . 90 5.2.1 Chemical Reaction Method . . . . . . . . . . . . . . . . . . . 90 5.2.2 Infrared Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . 90 5.2.3 Raman Spectroscopy. . . . . . . . . . . . . . . . . . . . . . . . 92 5.2.4 UV-Visible Spectroscopy. . . . . . . . . . . . . . . . . . . . . 93 5.2.5 Nuclear Magnetic Resonance Spectroscopy . . . . . . . . 95 5.2.6 Electron Spin Resonance . . . . . . . . . . . . . . . . . . . . . 98 5.3 Characterization of Morphology and Physical Structure of Polymer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 5.3.1 Transmission Electron Microscopy . . . . . . . . . . . . . . 100 5.3.2 X-Ray Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . 102 5.3.3 Atomic Force Microscopy . . . . . . . . . . . . . . . . . . . . 103 5.4 Characterization of Thermal Properties of Polymers . . . . . . . . 104 5.4.1 Differential Thermal Analysis and Differential Scanning Calorimetry . . . . . . . . . . . . . . . . . . . . . . . 104 5.4.2 Thermomechanical Analysis . . . . . . . . . . . . . . . . . . 106 5.4.3 Thermogravimetric Analysis . . . . . . . . . . . . . . . . . . 107 5.4.4 Flammability Test. . . . . . . . . . . . . . . . . . . . . . . . . . 108 5.5 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 6 Step Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 6.1 Chemical Reactions and Reaction Mechanisms of Step Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 6.1.1 Carbonyl Addition: Elimination Reaction Mechanism. . . . . . . . . . . . . . . . . . . . . . . . 113 6.1.2 Carbonyl Addition: Substitution Reaction Mechanism. . . . . . . . . . . . . . . . . . . . . . . . 115 6.1.3 Nucleophilic Substitution Reaction Mechanism . . . . . 116 6.1.4 Double-Bond Addition Reaction Mechanism . . . . . . . 116 6.1.5 Free-Radical Coupling . . . . . . . . . . . . . . . . . . . . . . 117 6.1.6 Aromatic Electrophilic-Substitution Reaction Mechanism. . . . . . . . . . . . . . . . . . . . . . . . 117 6.2 Reaction Kinetics of Step Polymerization . . . . . . . . . . . . . . . 117 6.3 Molecular Weight Control in Step Polymerization . . . . . . . . . 119 6.4 Molecular Weight Distribution . . . . . . . . . . . . . . . . . . . . . . . 122 6.5 Network Formation from Step Polymerization . . . . . . . . . . . . 124 x Contents
Contents xi 6.6 Step Copolymerization.....·..··················· 127 6.7 Techniques of Step Polymerization.................... 129 6.8 Synthesis of Dendritic Polymers.·.·.·············· 130 6.8.1 Divergent Method...··.·..·..······ 130 6.8.2 Convergent System........................ 131 6.8.3 Molecular Weight of Dendrimer..··..·········· 133 6.9 Hyperbranched Copolymer......................... 133 6.10 Problems...........··.. 134 References.········ 135 7 Radical Chain Polymerization........,..·.·......··...·. 137 7.1 Effect of Chemical Structure of Monomer on the Structural Arrangement of Polymer......·····.···. 138 7.2 Initiators of Radical Chain Polymerization..·.....······· 142 7.2.1 Thermal Initiators.......................... 142 7.2.2 Decomposition Temperature and Half-Life of Thermal Initiators.,......·,..,.·.···..· 144 7.2.3 Initiation Promoters,.,,...··············· 147 7.2.4 Redox Initiators...················ 147 7.2.5 Photoinitiators....。.·· 148 7.2.6 Electrochemical Initiation....... 149 7.3 Techniques of Free Radical Chain Polymerization 150 7.3.1 Bulk Polymerization..·.....·.....········· 150 7.3.2 Suspension Polymerization·..·,....·.......·· 150 7.3.3 Solution Polymerization............ 151 7.3.4 Emulsion Polymerization,...················· 151 7.4 Reaction Mechanism of Free Radical Chain Polymerization..............。.····· 153 7.5 Kinetics of Free Radical Chain Polymerization....······· 155 7.5.1 Rate of Polymerization...................... 156 7.5.2 Average Kinetic Chain Length下，..........·.. 157 7.5.3 Chain Transfer Reactions .......... 158 7.6 Living Polymerization..............·...··..······ 162 7.6.1 Living Radical Polymerization...... 444 162 7.6.2 Atom Transfer Radical Polymerization... 163 7.6.3 Nitroxide-Mediated Polymerization.............. 164 7.6.4 Radical Addition-Fragmentation Transfer ........ 164 7.7 Polymerization of Dienes........................... 165 7.8 Temperature Effect of the Free Radical Polymerization...···. 168 7.8.1 Activation Energy and Frequency Factor.......... 169 7.8.2 Rate of Polymerization.......,.....·.,·.···. 170 7.8.3 Degree of Polymerization················ 171
6.6 Step Copolymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 6.7 Techniques of Step Polymerization. . . . . . . . . . . . . . . . . . . . 129 6.8 Synthesis of Dendritic Polymers. . . . . . . . . . . . . . . . . . . . . . 130 6.8.1 Divergent Method. . . . . . . . . . . . . . . . . . . . . . . . . . 130 6.8.2 Convergent System . . . . . . . . . . . . . . . . . . . . . . . . . 131 6.8.3 Molecular Weight of Dendrimer. . . . . . . . . . . . . . . . 133 6.9 Hyperbranched Copolymer . . . . . . . . . . . . . . . . . . . . . . . . . 133 6.10 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 7 Radical Chain Polymerization. . . . . . . . . . . . . . . . . . . . . . . . . . . 137 7.1 Effect of Chemical Structure of Monomer on the Structural Arrangement of Polymer. . . . . . . . . . . . . . . 138 7.2 Initiators of Radical Chain Polymerization. . . . . . . . . . . . . . . 142 7.2.1 Thermal Initiators . . . . . . . . . . . . . . . . . . . . . . . . . . 142 7.2.2 Decomposition Temperature and Half-Life of Thermal Initiators . . . . . . . . . . . . . . . . . . . . . . . . 144 7.2.3 Initiation Promoters . . . . . . . . . . . . . . . . . . . . . . . . 147 7.2.4 Redox Initiators . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 7.2.5 Photoinitiators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 7.2.6 Electrochemical Initiation . . . . . . . . . . . . . . . . . . . . 149 7.3 Techniques of Free Radical Chain Polymerization . . . . . . . . . 150 7.3.1 Bulk Polymerization . . . . . . . . . . . . . . . . . . . . . . . . 150 7.3.2 Suspension Polymerization . . . . . . . . . . . . . . . . . . . 150 7.3.3 Solution Polymerization . . . . . . . . . . . . . . . . . . . . . 151 7.3.4 Emulsion Polymerization. . . . . . . . . . . . . . . . . . . . . 151 7.4 Reaction Mechanism of Free Radical Chain Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 7.5 Kinetics of Free Radical Chain Polymerization . . . . . . . . . . . 155 7.5.1 Rate of Polymerization . . . . . . . . . . . . . . . . . . . . . . 156 7.5.2 Average Kinetic Chain Length m . . . . . . . . . . . . . . . 157 7.5.3 Chain Transfer Reactions . . . . . . . . . . . . . . . . . . . . 158 7.6 Living Polymerization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 7.6.1 Living Radical Polymerization . . . . . . . . . . . . . . . . . 162 7.6.2 Atom Transfer Radical Polymerization . . . . . . . . . . . 163 7.6.3 Nitroxide-Mediated Polymerization. . . . . . . . . . . . . . 164 7.6.4 Radical Addition-Fragmentation Transfer . . . . . . . . . 164 7.7 Polymerization of Dienes. . . . . . . . . . . . . . . . . . . . . . . . . . . 165 7.8 Temperature Effect of the Free Radical Polymerization. . . . . . 168 7.8.1 Activation Energy and Frequency Factor. . . . . . . . . . 169 7.8.2 Rate of Polymerization . . . . . . . . . . . . . . . . . . . . . . 170 7.8.3 Degree of Polymerization . . . . . . . . . . . . . . . . . . . . 171 Contents xi
妨 Contents 7.9 Thermodynamics of Free Radical Polymerization.......... 172 7.9.1 Monomer Reactivity.....,.................. 173 7.9.2 Ceiling Temperature.··················· 175 7.9.3 Characteristics of AS Values of Free Radical Polymerization.......······ 176 7.l0 Molecular Weight Distribution at Low Conversion.···.···· 176 7.11 Synthesis of Commercial Polymers.................... 178 7.ll.1 Polyethylene......·.················· 178 7.l12 Polystyrene....·.······· 179 7.ll.3 Polyvinyl Chloride.........·.···· 180 7.ll.4 Polyvinyl Acetate......··..·.··..·.······· 180 7.11.5 Polyvinylidene Chloride .................... 180 7.11.6 Acryl Polymer.·.,···.·…············ 180 7.l1.7 Fluoropolymers....·················· 181 7.11.8 Cost of Common Polymers.........·.....···. 182 712 Problems.··················· 182 References......。t。。···+· 183 8 Ionic Chain Polymerization..·.....····················· 185 8.1 Characteristics of Ionic Chain Polymerization............ 187 8.2 Cationic Polymerization....·............·.······· 189 8.2.1 Initiators of Cationic Polymerization............. 189 8.2.2 Reaction Mechanisms of Cationic Polymerization .. 190 8.2.3 Kinetics of Cationic Polymerization............. 196 8.2.4 Commercial Cationic Polymerization............ 200 8.3 Anionic Polymerization.··.························ 201 8.3.1 Reaction Mechanisms of Anionic Polymerization.... 201 8.3.2 Kinetics of Anionic Polymerization with Termination..············ 204 8.4 Group Transfer Polymerization....................... 209 8.5 Chain Polymerization of Carbonyl Monomer............. 213 8.5.1 Anionic Polymerization of Carbonyl Monomer 213 8.5.2 Cationic Polymerization of Carbonyl Monomer..... 215 8.5.3 Radical Polymerization of Carbonyl Monomer...... 215 8.5.4 End-Capping Polymerization.................. 216 86 Problems..….·。,···…······…··…···· 217 References...,,·.。········· 218 9 Coordination Polymerization.,·..·.····················· 219 g.1 Heterogeneous Ziegler--Natta Polymerization......·..···. 219 9.l.1 Catalysts........········· 219 9.l.2 Reaction Mechanisms...··.················· 222 9.2 Homogeneous Ziegler-Natta Polymerization............. 225 9.3 Ziegler--Natta Copolymerization.···.················· 229
7.9 Thermodynamics of Free Radical Polymerization . . . . . . . . . . 172 7.9.1 Monomer Reactivity . . . . . . . . . . . . . . . . . . . . . . . . 173 7.9.2 Ceiling Temperature . . . . . . . . . . . . . . . . . . . . . . . . 175 7.9.3 Characteristics of DS Values of Free Radical Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 7.10 Molecular Weight Distribution at Low Conversion . . . . . . . . . 176 7.11 Synthesis of Commercial Polymers. . . . . . . . . . . . . . . . . . . . 178 7.11.1 Polyethylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 7.11.2 Polystyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 7.11.3 Polyvinyl Chloride . . . . . . . . . . . . . . . . . . . . . . . . . 180 7.11.4 Polyvinyl Acetate . . . . . . . . . . . . . . . . . . . . . . . . . . 180 7.11.5 Polyvinylidene Chloride . . . . . . . . . . . . . . . . . . . . . 180 7.11.6 Acryl Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 7.11.7 Fluoropolymers . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 7.11.8 Cost of Common Polymers . . . . . . . . . . . . . . . . . . . 182 7.12 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 8 Ionic Chain Polymerization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 8.1 Characteristics of Ionic Chain Polymerization . . . . . . . . . . . . 187 8.2 Cationic Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 8.2.1 Initiators of Cationic Polymerization. . . . . . . . . . . . . 189 8.2.2 Reaction Mechanisms of Cationic Polymerization . . . 190 8.2.3 Kinetics of Cationic Polymerization . . . . . . . . . . . . . 196 8.2.4 Commercial Cationic Polymerization . . . . . . . . . . . . 200 8.3 Anionic Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 8.3.1 Reaction Mechanisms of Anionic Polymerization . . . . 201 8.3.2 Kinetics of Anionic Polymerization with Termination . . . . . . . . . . . . . . . . . . . . . . . . . . 204 8.4 Group Transfer Polymerization. . . . . . . . . . . . . . . . . . . . . . . 209 8.5 Chain Polymerization of Carbonyl Monomer . . . . . . . . . . . . . 213 8.5.1 Anionic Polymerization of Carbonyl Monomer . . . . . 213 8.5.2 Cationic Polymerization of Carbonyl Monomer . . . . . 215 8.5.3 Radical Polymerization of Carbonyl Monomer. . . . . . 215 8.5.4 End-Capping Polymerization . . . . . . . . . . . . . . . . . . 216 8.6 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 9 Coordination Polymerization. . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 9.1 Heterogeneous Ziegler–Natta Polymerization . . . . . . . . . . . . . 219 9.1.1 Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 9.1.2 Reaction Mechanisms . . . . . . . . . . . . . . . . . . . . . . . 222 9.2 Homogeneous Ziegler–Natta Polymerization . . . . . . . . . . . . . 225 9.3 Ziegler–Natta Copolymerization . . . . . . . . . . . . . . . . . . . . . . 229 xii Contents
Contents xiii 9.4 Metathesis Polymerization.....····················· 230 9.5 Problems......,。...:..。.。。·…·· 231 References·· 232 10 Chain Copolymerization..................·..··..····· 233 10.1 Reaction Kinetics of Free Radical Copolymerization 234 10.1.1 Types of Copolymerization Behavior............ 237 10.1.2 Effect of Reaction Conditions on Radical Copolymerization..·············· 241 10.1.3 Reactivity and Composition of Free Radical Copolymerization 243 10.1.4 Rate of Polymerization of Free Radical Copolymerization...···.·.·············· 253 l0.2 Cationic Copolymerization.......·...,·.·.·········· 256 10.3 Anionic Copolymerization.......................... 259 10.4 Copolymerization Involving Dienes..················· 260 10.5 Block Copolymers...··...·。···················· 261 10.6 Commercial Copolymers....···...················ 263 10.7 Problems.·· 263 References.....。·。 265 l1Ring-0 pening Polymerization....·.·............·.·.·.· 267 11.1 Reactivity of Cyclic Monomers .... 267 11.2 General Aspects of Mechanisms and Kinetics............ 270 113 Cyclic Ethers................................... 271 ll.3.1 Anionic Polymerization of Epoxides..·.·.······ 272 11.3.2 Cationic Polymerization of Epoxides 277 11.3.3 Polymerization of Cyclic Acetals............... 282 ll.3.4 Kinetic Characteristics·..············· 283 11.3.5 Thermodynamic Characteristics................ 285 11.3.6 Commercial Applications of Polymers of Cyclic Ether...·········… 287 288 11.4.1 Cationic Polymerization 444444.44.44444。 288 11.4.2 Hydrolytic Polymerization.................... 290 1l.4.3 Anionic Polymerization.......·....·········· 291 11.4.4 Reactivity of Lactam.........:....·..······ 294 115 Cyclosiloxanes....。...。.。.··········· 294 11.6 Copolymerization.···················· 296 11.7 Problems.........·. 44.444.44.444.4+ 298 References ......... 299 Index.。,。 301
9.4 Metathesis Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . 230 9.5 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 10 Chain Copolymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 10.1 Reaction Kinetics of Free Radical Copolymerization . . . . . . . 234 10.1.1 Types of Copolymerization Behavior . . . . . . . . . . . . 237 10.1.2 Effect of Reaction Conditions on Radical Copolymerization . . . . . . . . . . . . . . . . . . . . . . . . . . 241 10.1.3 Reactivity and Composition of Free Radical Copolymerization . . . . . . . . . . . . . . 243 10.1.4 Rate of Polymerization of Free Radical Copolymerization . . . . . . . . . . . . . . . . . . . . . . . . . . 253 10.2 Cationic Copolymerization. . . . . . . . . . . . . . . . . . . . . . . . . . 256 10.3 Anionic Copolymerization . . . . . . . . . . . . . . . . . . . . . . . . . . 259 10.4 Copolymerization Involving Dienes . . . . . . . . . . . . . . . . . . . 260 10.5 Block Copolymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 10.6 Commercial Copolymers . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 10.7 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 11 Ring-Opening Polymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 11.1 Reactivity of Cyclic Monomers . . . . . . . . . . . . . . . . . . . . . . 267 11.2 General Aspects of Mechanisms and Kinetics . . . . . . . . . . . . 270 11.3 Cyclic Ethers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 11.3.1 Anionic Polymerization of Epoxides . . . . . . . . . . . . . 272 11.3.2 Cationic Polymerization of Epoxides . . . . . . . . . . . . 277 11.3.3 Polymerization of Cyclic Acetals . . . . . . . . . . . . . . . 282 11.3.4 Kinetic Characteristics . . . . . . . . . . . . . . . . . . . . . . 283 11.3.5 Thermodynamic Characteristics . . . . . . . . . . . . . . . . 285 11.3.6 Commercial Applications of Polymers of Cyclic Ether. . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 11.4 Lactams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 11.4.1 Cationic Polymerization . . . . . . . . . . . . . . . . . . . . . 288 11.4.2 Hydrolytic Polymerization . . . . . . . . . . . . . . . . . . . . 290 11.4.3 Anionic Polymerization . . . . . . . . . . . . . . . . . . . . . . 291 11.4.4 Reactivity of Lactam. . . . . . . . . . . . . . . . . . . . . . . . 294 11.5 Cyclosiloxanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 11.6 Copolymerization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 11.7 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Contents xiii
Chapter 1 Introduction Synthetic polymers [1]are vital materials used in modern daily life from pack- aging,electronics,medical devices,clothing,vehicles,buildings,etc.,due to their ease of processing and light weight.The first synthetic polymer,a phenol-form- aldehyde resin,was invented in the early 1900s by Leo Baekeland [2].It was a commercial success invention although most of scientists had no clear concept of polymer structure at that time.Wallace Carothers invented very important poly- mers of neoprene rubber and Nylon in 1930s which shaped the leadership of DuPont in polymer industry.Hermann Staudinger developed theoretical expla- nations of remarkable properties of polymers by ordinary intermolecular forces between molecules of very high molecular weight.He was awarded the Nobel Prize in Chemistry in 1953 for this outstanding contribution.World War II led to significant advances in polymer chemistry with the development of synthetic rubber as natural rubber was not accessible to the Allies.Karl Ziegler and Giulio Natta won the Nobel Prize in Chemistry in 1963,jointly for the development of coordination polymerization to have controlled stereochemistry of polymers using coordination catalysts.Their work has revolutionized the polymer industry to synthesize stereoregular polymers that have mechanical properties superior than that of non-stereoregular polymers.Equally significant work was done by Paul Flory 1974,Nobel laureate on the quantitative investigations of polymer behaviors in solution or in bulk. Most of polymers are insulators,so they have passive functions and used as a bulk material for structure or as thin layer for coating barrier.In 1977,Alan Heeger,Alan MacDiarmid,and Hideki Shirakawa reported high conductivity in iodine-doped polyacetylene.This research earned them the 2000 Nobel Prize in Chemistry.Since then,the application of polymer has expanded into active functional area such as light emitting diode,sensor,solar cell,etc.Polymers can be tailor made to meet the requirements of specific application through molecular design and synthesis.Therefore,they have become the material of choice to face the ever fast changing world from electronics to medical applications. The physical properties of polymers are mainly determined by their chemical structures.Chemical structures of polymers affect their flow and morphology that results in different physical properties.The processability of polymers is controlled W.-F.Su,Principles of Polymer Design and Synthesis, 1 Lecture Notes in Chemistry 82,DOI:10.1007/978-3-642-38730-2_1, Springer-Verlag Berlin Heidelberg 2013
Chapter 1 Introduction Synthetic polymers [1] are vital materials used in modern daily life from packaging, electronics, medical devices, clothing, vehicles, buildings, etc., due to their ease of processing and light weight. The first synthetic polymer, a phenol-formaldehyde resin, was invented in the early 1900s by Leo Baekeland [2]. It was a commercial success invention although most of scientists had no clear concept of polymer structure at that time. Wallace Carothers invented very important polymers of neoprene rubber and Nylon in 1930s which shaped the leadership of DuPont in polymer industry. Hermann Staudinger developed theoretical explanations of remarkable properties of polymers by ordinary intermolecular forces between molecules of very high molecular weight. He was awarded the Nobel Prize in Chemistry in 1953 for this outstanding contribution. World War II led to significant advances in polymer chemistry with the development of synthetic rubber as natural rubber was not accessible to the Allies. Karl Ziegler and Giulio Natta won the Nobel Prize in Chemistry in 1963, jointly for the development of coordination polymerization to have controlled stereochemistry of polymers using coordination catalysts. Their work has revolutionized the polymer industry to synthesize stereoregular polymers that have mechanical properties superior than that of non-stereoregular polymers. Equally significant work was done by Paul Flory 1974, Nobel laureate on the quantitative investigations of polymer behaviors in solution or in bulk. Most of polymers are insulators, so they have passive functions and used as a bulk material for structure or as thin layer for coating barrier. In 1977, Alan Heeger, Alan MacDiarmid, and Hideki Shirakawa reported high conductivity in iodine-doped polyacetylene. This research earned them the 2000 Nobel Prize in Chemistry. Since then, the application of polymer has expanded into active functional area such as light emitting diode, sensor, solar cell, etc. Polymers can be tailor made to meet the requirements of specific application through molecular design and synthesis. Therefore, they have become the material of choice to face the ever fast changing world from electronics to medical applications. The physical properties of polymers are mainly determined by their chemical structures. Chemical structures of polymers affect their flow and morphology that results in different physical properties. The processability of polymers is controlled W.-F. Su, Principles of Polymer Design and Synthesis, Lecture Notes in Chemistry 82, DOI: 10.1007/978-3-642-38730-2_1, Springer-Verlag Berlin Heidelberg 2013 1
2 I Introduction Fig.1.1 Chemical structures (a)Monomer (b)Polymer of(a)monomers and(b)their corresponding polymers H2C=CH2 十CHaCHz H2C=CHCI H2C—CH2 -CHzCHz0jn HOCH2CH2OH -CH2CH2O f-O斗 by their flow characteristics in neat form or in solution which affects by their molecular weight. Polymers are built up by linking together of large number of "monomers." Monomers are small molecules with functional groups (organic compounds)and they can react with each other to form a large molecule.Figure 1.1 shows some commonly used polymers with their chemical structures of monomers and their corresponding polymers.The polymers have to have molecular weight larger than 10,000 to exhibit good mechanical properties for structural use.Oligomer is a molecule that has molecular weight between 1,000 and 10,000.The oligomer has been widely used in coating applications.End group is the chemical structure at the end of the polymer chains.When the polymer is ended with a functional group, such as CH3CH2-[CH2CH2]-CH=CH2,the polymer is called telechelic polymer. In the same way,reactive oligomer is oligomer that contains end groups and capable to undergo polymerization. The size of polymer is determined by the degree of polymerization(DP).It is a total number of structural units,including end groups,and is related to both chain length and molecular weight.For example,the molecular weight of polymethac- rylate with DP =500 is 500 multiplying by 74 (weight of unit)=37,000. Because polymer chains within a given polymer sample are always of varying lengths,we need to use average value,such as number-average molecular weight (M),weight-average molecular weight(Mw),etc.The molecular weight distri- bution (PDD)is defined as dividing Mw over Mn
by their flow characteristics in neat form or in solution which affects by their molecular weight. Polymers are built up by linking together of large number of ‘‘monomers.’’ Monomers are small molecules with functional groups (organic compounds) and they can react with each other to form a large molecule. Figure 1.1 shows some commonly used polymers with their chemical structures of monomers and their corresponding polymers. The polymers have to have molecular weight larger than 10,000 to exhibit good mechanical properties for structural use. Oligomer is a molecule that has molecular weight between 1,000 and 10,000. The oligomer has been widely used in coating applications. End group is the chemical structure at the end of the polymer chains. When the polymer is ended with a functional group, such as CH3CH2–[CH2CH2]n–CH=CH2, the polymer is called telechelic polymer. In the same way, reactive oligomer is oligomer that contains end groups and capable to undergo polymerization. The size of polymer is determined by the degree of polymerization (DP). It is a total number of structural units, including end groups, and is related to both chain length and molecular weight. For example, the molecular weight of polymethacrylate with DP = 500 is 500 multiplying by 74 (weight of unit) = 37,000. Because polymer chains within a given polymer sample are always of varying lengths, we need to use average value, such as number-average molecular weight Mð Þn , weight-average molecular weight Mð Þ w , etc. The molecular weight distribution (PDI) is defined as dividing M w over M n. Fig. 1.1 Chemical structures of (a) monomers and (b) their corresponding polymers 2 1 Introduction
