Organocatalysis is revolutionizing polymer chemistry, offering a sustainable, cost-effective alternative to traditional metal-based catalysts. Organocatalysts in Polymer Chemistry: Synthesis and Applications presents a detailed summary of the development of organocatalysts and their transformative impact on polymer synthesis. Contributions by an international team of specialists present cutting-edge methodologies for creating precise macromolecular structures, covering a wide range of polymerization methods and practical applications.
Edited by Professor Zhibo Li, an acknowledged expert in polymer chemistry, the book covers the use of organocatalysts in processes such as ring-opening polymerization, controlled radical polymerization, and polymer depolymerization. It offers vital insights into the synthesis of advanced, biodegradable, and metal-free materials, making it a valuable resource of both foundational knowledge and the latest research breakthroughs in polymer chemistry.
Exploring the development, advantages, and applications of organocatalysts in polymer synthesis, this book: - Presents advanced techniques for creating precise polymer architectures, including molecular weight, stereochemistry, and topology control - Discusses applications of organocatalysts in ring-opening polymerization (ROP), controlled radical polymerization, and copolymerization techniques - Highlights organocatalysis as a metal-free, cost-effective, and environmentally friendly alternative for polymer synthesis - Examines the role of organocatalysts in recycling and depolymerizing commodity polymers such as PET and polycarbonate - Addresses the synthesis of degradable polymers for biomedical, electronic, and environmental uses - Summarizes advancements over the past two decades and explores emerging trends in polymer chemistry
Organocatalysts in Polymer Chemistry is essential reading for postgraduate students, researchers, and industrial professionals in polymer chemistry, materials science, and sustainable catalysis. It is also an essential reference for catalytic chemists, organic chemists, and chemical engineers engaged in the synthesis and application of polymers.
Table of Contents
Preface xiii
1 Organocatalyzed Ring-Opening Polymerization of Cyclic Esters Toward Degradable Polymers 1
Feng Li, Takuya Isono, and Toshifumi Satoh
1.1 General Introduction 1
1.2 Polymerization Mechanism 3
1.2.1 Nucleophilic Catalysts 3
1.2.2 Base Catalysts 4
1.2.3 Acid Catalysts 6
1.2.4 Ionic Catalysts 7
1.2.5 Bifunctional and Multifunctional Catalysts 9
1.3 Recent Trends in Organocatalyst Development 10
1.3.1 Higher Catalytic Efficiency 11
1.3.2 Higher Selectivity 12
1.3.3 Higher-Temperature Tolerance 17
1.3.4 Safety Considerations 19
1.4 Toward Higher Degradability and Recyclability 21
1.4.1 Incorporation of Chemically Labile Moieties into Polymer Chains for Higher Degradability 22
1.4.2 Development of Novel Chemically Recyclable Polyesters 25
1.5 Summary and Outlook 29
References 30
2 Organocatalyzed Copolymerization of CO 2 with Epoxide Toward Polycarbonate Synthesis 45
Xiaoshuang Feng and Yves Gnanou
2.1 Introduction 45
2.2 Discovery of TEB Catalyzed CO2 /Epoxides Copolymerization 46
2.3 Development of TEB Catalyzed CO2 /Epoxides Copolymerization 50
2.4 Synthesis of CO2 -Based Block Copolymers 55
2.4.1 One-Step Ter-, Quater-Polymerization 55
2.4.2 Polycarbonate Block Copolymers from Orthogonal Polymerization 58
2.4.3 All-Polycarbonate Block Copolymers 60
2.4.4 CO2 -Based Triblock Copolymers 62
2.5 Bifunctional Organoboron Catalysts 65
2.5.1 9-BBN Tethered with Ammonium Cations 65
2.5.2 9-BBN Tethered with Phosphonium Cations 67
2.5.3 Borinane Tethered with Ammonium Cations 68
2.6 Conclusions 69
References 70
3 Organocatalyzed Ring-Opening Copolymerization of Cyclic Anhydride and Cyclic Ether (Acetal) 79
Xun Zhang, Chengjian Zhang, and Xinghong Zhang
3.1 Introduction 79
3.2 The Copolymerization of Epoxide with Cyclic Anhydride 81
3.2.1 The Scope of Epoxides and Cyclic Anhydrides 81
3.2.2 Metal Catalysts 82
3.2.3 Organocatalysts 85
3.2.3.1 Organic Bases 86
3.2.3.2 Bicomponent Lewis Pair 88
3.2.3.3 Bifunctional Lewis Pair 92
3.3 The Copolymerization of Oxetane with Cyclic Anhydride 95
3.4 The Copolymerization of Tetrahydrofuran with Cyclic Anhydride 97
3.5 The Copolymerization of Cyclic Acetal (Aldehyde) with Cyclic Anhydride 100
3.6 Polyester-Based Block Copolymer 103
3.7 Conclusions and Outlook 105
References 107
4 Organocatalysts for the Preparation of Degradable and Closed-Loop Recyclable Polyesters 115
Yong Shen and Zhibo li
4.1 Introduction 115
4.2 Catalytic Mechanism of Various Organocatalysts 116
4.2.1 Electrophilic Monomer Activation Mechanism 116
4.2.2 Nucleophilic Monomer Activation Mechanism 117
4.2.3 Chain-End Activation Mechanism 117
4.2.4 Bifunctional Activation Mechanism 118
4.3 Organocatalytic ROP of Lactones or Lactides 119
4.3.1 γ-Butyrolactone and its Derivatives 119
4.3.2 δ-Valerolactone and ε-Caprolactone 124
4.3.3 δ-Valerolactone Derivatives 129
4.3.4 Lactide 131
4.3.5 Large-Membered Lactones 135
4.4 Summary and Perspective 136
References 137
5 Organo-Catalyst Catalyzed Ring Opening Polymerization of N-Carboxyanhydrides 147
Chongyi Chen and Zhibo li
5.1 Introduction 147
5.2 Organo-Catalysts for NCA Ring Opening Polymerization 149
5.2.1 Organo-Catalysts Before 2010 149
5.2.2 Amine-Based Organo-Catalysts 150
5.2.3 Other Organo-Catalysts 156
5.2.4 Autocatalysis of NCA Ring Opening Polymerization 160
5.3 Conclusions and Future Prospects 165
Abbreviations 166
References 166
6 Organocatalyst Catalyzed Ring Opening Polymerization of O(S)-Carboxyanhydride to Produce High Performance Poly(thio)esters 173
Yinuo Zhu and Youhua Tao
6.1 Introduction 173
6.2 Synthesis and Purification of O(S)-Carboxyanhydride Monomers 175
6.3 The Racemization of α-Proton 175
6.4 Organocatalyst for OCA Polymerization 176
6.4.1 ROP Catalyzed by DMAP 176
6.4.2 ROP Catalyzed by N-Heterocyclic Carbenes 178
6.4.3 ROP Catalyzed by Acid/Base Adducts 178
6.4.4 Thiourea-Based Organocatalysts for OCAs Polymerization 179
6.5 Organocatalyst for SCA Polymerization 182
6.6 Conclusion and Perspective 185
References 186
7 Organocatalyzed Stereoselective Ring-Opening (Co)Polymerization 191
Shaofeng Liu and Daniel Taton
7.1 Introduction 191
7.2 Mechanisms in the Organocatalyzed Stereoselective ROP 192
7.3 Organic Acids for Stereoselective ROP of rac-LA 193
7.4 Organic Bases for Stereoselective ROP of rac-LA 196
7.4.1 N-Heterocyclic Carbenes (NHCs) 196
7.4.2 Amidines and Guanidines 198
7.4.3 Phosphazenes 198
7.5 Dual Organocatalysts 200
7.5.1 Mono-Component Bifunctional Organocatalysts 200
7.5.2 Bi-Component Organocatalysts 203
7.6 Organocatalysts for Stereoselective ROP of Other Cyclic Monomers 211
7.7 Conclusion 212
Acknowledgements 213
References 213
8 Ring-Opening Polymerization of Epoxides Through Organocatalysis 219
Lijun Liu, Yuxuan Zhou, Xingyu Tang, and Junpeng Zhao
8.1 Introduction 219
8.2 Catalyst and Mechanism 220
8.2.1 Single-Component Catalyst 221
8.2.1.1 Base 221
8.2.1.2 Acid 223
8.2.2 Two-Component Catalyst 225
8.3 Synthesis of Functionalized Polyether 227
8.3.1 End-Group Functionalization 228
8.3.2 Pendant-Group Functionalization 230
8.4 Synthesis of Polyether-Based Block Copolymer 232
8.4.1 One-Pot Two-Step Block Copolymerization 232
8.4.2 One-Step Block Copolymerization 236
8.5 Conclusion and Outlook 240
References 240
9 Organo-Borane Catalysis for Ring Opening Polymerization of Epoxides 253
Xiaowu Wang and Zhibo li
9.1 Introduction 253
9.2 Fundamentals of Borane Compounds 253
9.2.1 General Characteristics of Boron and Boranes 253
9.2.2 Bond Length and Strengths 254
9.2.3 Characterization 255
9.2.4 Lewis Acidity of (Organo)Borane 255
9.3 Et3B-Mediated ROP of Epoxides 256
9.3.1 Introduction of ROP of Epoxides 256
9.3.2 Et3B -Based Binary Lewis Pair Systems in the ROP of Epoxides 258
9.3.3 Mechanism of Et3B Mediated ROP of Epoxides 260
9.3.4 Poly(alkylene oxide) Structures: Novel and Innovative Polyether Architectures 261
9.4 Modified Organoborane Mediated ROP of Epoxides 264
9.4.1 One-Component Ammonium Borane-Based Lewis Pair Systems Mediated ROP of Epoxides 265
9.4.2 One-Component Phosphonium Borane-Based Lewis Pair Systems Mediated ROP of Epoxides 269
9.4.3 Silicon-Based Borane Lewis Pair System 272
9.4.4 Macromolecular Organoborane Mediated ROP of Epoxides 272
9.4.5 Poly(alkylene oxide) Structures: Innovative Polyether Architectures 274
9.5 Chiral Organoborane Mediated Asymmetric ROP of Epoxides 279
9.6 Conclusion and Outlook 281
References 283
10 Organocatalyst for Ring-Opening Polymerization of Cyclosiloxanes Toward Polysiloxanes 289
Na Zhao, Yuetao liu, and Zhibo li
10.1 Introduction 289
10.2 Anionic ROP of Cyclosiloxanes 291
10.3 Phosphazene-Catalyzed Anionic ROP of Cyclosiloxanes 291
10.3.1 Schwesinger’s Phosphazene Bases 293
10.3.2 Phosphazenium Hydroxide P5OH 293
10.3.3 Cyclic Trimeric Phosphazene Base (CTPB) 295
10.3.4 Trisphosphazene Base - C3N3 -Me-P3 297
10.3.5 Guanidinophosphazene - HTGCP 297
10.4 Guanidines-Catalyzed Anionic ROP of Cyclosiloxanes 297
10.5 Phosphorus Ylides-Catalyzed Anionic ROP of Cyclosiloxanes 302
10.6 NHC-Catalyzed Anionic ROP of Cyclosiloxanes 303
10.7 Conclusion 304
References 305
11 Organic Lewis Pair in Polymer Synthesis 309
Mingqian Wang, Zhiqiang Ding, Bin Wang, and Yuesheng li
11.1 Lewis Pair Catalytic Ring-Opening Polymerization of Cyclic Esters 309
11.2 Mechanisms for Lewis Pair-Catalyzed ROP of Cyclic Esters 310
11.3 Lewis Pairs Used for ROP of Cyclic Ester 311
11.3.1 Organoboron-Based Lewis Pair 311
11.3.2 Organoaluminum-Based Lewis Pair 313
11.3.3 Organozinc-Based Lewis Pair 315
11.3.4 Metal Halide-Based LPs 318
References 322
12 Organocatalysts for Radical Polymerization 325
Chenyu Wu, Qiang Ma, Baoshan Hou, Zhilei Wang, Zikuan Wang, and Saihu Liao
12.1 Photocontrolled Organocatalyzed Radical Polymerization 325
12.2 Organocatalyzed Atom Transfer Radical Polymerization (O-ATRP) 328
12.2.1 Mechanism of O-ATRP 328
12.2.2 Polynuclear Aromatic Hydrocarbons 328
12.2.3 Phenothiazine Derivatives 329
12.2.4 Dihydrophenazine Derivatives 330
12.2.5 Phenoxazine Derivatives 331
12.2.6 Dimethylacridine Derivatives 332
12.2.7 Organic Donor-Acceptor Scaffolds 333
12.2.8 Heteroatom-Doped Anthanthrene Derivatives 334
12.2.9 Other Classes 335
12.3 Photoinduced Electron/Energy Transfer Reversible Addition-Fragmentation Chain Transfer (PET-RAFT) 337
12.3.1 Mechanism of PET-RAFT 337
12.3.2 Porphyrin Derivatives 338
12.3.3 Fluorescein Derivatives 340
12.3.4 Phthalocyanine Derivatives 340
12.3.5 Other Classes 340
12.4 Structure-Property-Performance Relationships 341
12.4.1 Structure-Property-Relationships 341
12.4.2 Photon Absorption 342
12.4.2.1 Theory for Absorption Spectrum 342
12.4.2.2 Full Width at Half Maximum 343
12.4.2.3 Maximum Absorption Wavelength 344
12.4.2.4 Molar Extinction Coefficient 344
12.4.3 Excited-State Evolution 346
12.4.3.1 Quantum Yield for Long-Lived State 346
12.4.3.2 Theory for Fluorescence 347
12.4.3.3 Theory for Internal Conversion 348
12.4.3.4 Theory for Intersystem Crossing 349
12.4.4 Activation 350
12.4.5 Deactivation 352
12.4.6 Property-Performance Relationships 353
12.5 Outlook 354
References 355
13 Organocatalyst-Catalyzed Non-Radical Photopolymerizations 365
Yun Liao and Saihu Liao
13.1 Introduction 365
13.2 Organocatalysts for Photocontrolled Cationic Polymerization 366
13.3 Organocatalysts for Photocontrolled Ring-Opening Polymerization 377
13.4 Organocatalysts for Photocontrolled Ring-Opening Metathesis Polymerization (ROMP) 384
13.5 Organocatalysts for Photocontrolled Step-Growth Polymerization 387
References 392
14 Enzyme-Catalyzed Controlled Radical Polymerization 399
Ruoyu Li and Zesheng An
14.1 Introduction 399
14.2 Enzymatic Deoxygenation in RAFT Polymerization 400
14.3 Enzymatic Initiation of RAFT Polymerization 403
14.4 Enzymatic Deoxygenation in ATRP 407
14.5 Enzyme-Catalyzed ATRP 408
14.6 Conclusions 411
Acknowledgments 411
References 411
15 Organocatalyst-Catalyzed Degradation of Polymers 419
Ge Yang and Zhibo li
15.1 Introduction 419
15.2 Chemical Degradation of Functional Polymers 420
15.2.1 Organic Bases and Organic Acids 420
15.2.2 Lonic Liquids and Acid-Base Salts 423
15.3 Photocatalytic Degradation of Non-Functional Polymers 426
15.4 Conclusion 427
References 429
Index 433
