Organocatalysts in Polymer Chemistry

Zhibo Li is Distinguished Professor at Qingdao University of Science and Technology, China. He earned his PhD from the University of Minnesota and completed postdoctoral research at UCLA, USA. With over 280 publications, Professor Li’s work spans polymer chemistry and catalysis. He is a recipient of the National Science Fund for Distinguished Young Scholars and serves as Associate Editor of Chinese Journal of Polymer Science and RSC Polymer Chemistry.

• Preface xiii1 Organocatalyzed Ring-Opening Polymerization of Cyclic Esters Toward Degradable Polymers 1Feng Li, Takuya Isono, and Toshifumi Satoh1.1 General Introduction 11.2 Polymerization Mechanism 31.2.1 Nucleophilic Catalysts 31.2.2 Base Catalysts 41.2.3 Acid Catalysts 61.2.4 Ionic Catalysts 71.2.5 Bifunctional and Multifunctional Catalysts 91.3 Recent Trends in Organocatalyst Development 101.3.1 Higher Catalytic Efficiency 111.3.2 Higher Selectivity 121.3.3 Higher-Temperature Tolerance 171.3.4 Safety Considerations 191.4 Toward Higher Degradability and Recyclability 211.4.1 Incorporation of Chemically Labile Moieties into Polymer Chains for Higher Degradability 221.4.2 Development of Novel Chemically Recyclable Polyesters 251.5 Summary and Outlook 29References 302 Organocatalyzed Copolymerization of CO 2 with Epoxide Toward Polycarbonate Synthesis 45Xiaoshuang Feng and Yves Gnanou2.1 Introduction 452.2 Discovery of TEB Catalyzed CO2 /Epoxides Copolymerization 462.3 Development of TEB Catalyzed CO2 /Epoxides Copolymerization 502.4 Synthesis of CO2 -Based Block Copolymers 552.4.1 One-Step Ter-, Quater-Polymerization 552.4.2 Polycarbonate Block Copolymers from Orthogonal Polymerization 582.4.3 All-Polycarbonate Block Copolymers 602.4.4 CO2 -Based Triblock Copolymers 622.5 Bifunctional Organoboron Catalysts 652.5.1 9-BBN Tethered with Ammonium Cations 652.5.2 9-BBN Tethered with Phosphonium Cations 672.5.3 Borinane Tethered with Ammonium Cations 682.6 Conclusions 69References 703 Organocatalyzed Ring-Opening Copolymerization of Cyclic Anhydride and Cyclic Ether (Acetal) 79Xun Zhang, Chengjian Zhang, and Xinghong Zhang3.1 Introduction 793.2 The Copolymerization of Epoxide with Cyclic Anhydride 813.2.1 The Scope of Epoxides and Cyclic Anhydrides 813.2.2 Metal Catalysts 823.2.3 Organocatalysts 853.2.3.1 Organic Bases 863.2.3.2 Bicomponent Lewis Pair 883.2.3.3 Bifunctional Lewis Pair 923.3 The Copolymerization of Oxetane with Cyclic Anhydride 953.4 The Copolymerization of Tetrahydrofuran with Cyclic Anhydride 973.5 The Copolymerization of Cyclic Acetal (Aldehyde) with Cyclic Anhydride 1003.6 Polyester-Based Block Copolymer 1033.7 Conclusions and Outlook 105References 1074 Organocatalysts for the Preparation of Degradable and Closed-Loop Recyclable Polyesters 115Yong Shen and Zhibo li4.1 Introduction 1154.2 Catalytic Mechanism of Various Organocatalysts 1164.2.1 Electrophilic Monomer Activation Mechanism 1164.2.2 Nucleophilic Monomer Activation Mechanism 1174.2.3 Chain-End Activation Mechanism 1174.2.4 Bifunctional Activation Mechanism 1184.3 Organocatalytic ROP of Lactones or Lactides 1194.3.1 γ-Butyrolactone and its Derivatives 1194.3.2 δ-Valerolactone and ε-Caprolactone 1244.3.3 δ-Valerolactone Derivatives 1294.3.4 Lactide 1314.3.5 Large-Membered Lactones 1354.4 Summary and Perspective 136References 1375 Organo-Catalyst Catalyzed Ring Opening Polymerization of N-Carboxyanhydrides 147Chongyi Chen and Zhibo li5.1 Introduction 1475.2 Organo-Catalysts for NCA Ring Opening Polymerization 1495.2.1 Organo-Catalysts Before 2010 1495.2.2 Amine-Based Organo-Catalysts 1505.2.3 Other Organo-Catalysts 1565.2.4 Autocatalysis of NCA Ring Opening Polymerization 1605.3 Conclusions and Future Prospects 165Abbreviations 166References 1666 Organocatalyst Catalyzed Ring Opening Polymerization of O(S)-Carboxyanhydride to Produce High Performance Poly(thio)esters 173Yinuo Zhu and Youhua Tao6.1 Introduction 1736.2 Synthesis and Purification of O(S)-Carboxyanhydride Monomers 1756.3 The Racemization of α-Proton 1756.4 Organocatalyst for OCA Polymerization 1766.4.1 ROP Catalyzed by DMAP 1766.4.2 ROP Catalyzed by N-Heterocyclic Carbenes 1786.4.3 ROP Catalyzed by Acid/Base Adducts 1786.4.4 Thiourea-Based Organocatalysts for OCAs Polymerization 1796.5 Organocatalyst for SCA Polymerization 1826.6 Conclusion and Perspective 185References 1867 Organocatalyzed Stereoselective Ring-Opening (Co)Polymerization 191Shaofeng Liu and Daniel Taton7.1 Introduction 1917.2 Mechanisms in the Organocatalyzed Stereoselective ROP 1927.3 Organic Acids for Stereoselective ROP of rac-LA 1937.4 Organic Bases for Stereoselective ROP of rac-LA 1967.4.1 N-Heterocyclic Carbenes (NHCs) 1967.4.2 Amidines and Guanidines 1987.4.3 Phosphazenes 1987.5 Dual Organocatalysts 2007.5.1 Mono-Component Bifunctional Organocatalysts 2007.5.2 Bi-Component Organocatalysts 2037.6 Organocatalysts for Stereoselective ROP of Other Cyclic Monomers 2117.7 Conclusion 212Acknowledgements 213References 2138 Ring-Opening Polymerization of Epoxides Through Organocatalysis 219Lijun Liu, Yuxuan Zhou, Xingyu Tang, and Junpeng Zhao8.1 Introduction 2198.2 Catalyst and Mechanism 2208.2.1 Single-Component Catalyst 2218.2.1.1 Base 2218.2.1.2 Acid 2238.2.2 Two-Component Catalyst 2258.3 Synthesis of Functionalized Polyether 2278.3.1 End-Group Functionalization 2288.3.2 Pendant-Group Functionalization 2308.4 Synthesis of Polyether-Based Block Copolymer 2328.4.1 One-Pot Two-Step Block Copolymerization 2328.4.2 One-Step Block Copolymerization 2368.5 Conclusion and Outlook 240References 2409 Organo-Borane Catalysis for Ring Opening Polymerization of Epoxides 253Xiaowu Wang and Zhibo li9.1 Introduction 2539.2 Fundamentals of Borane Compounds 2539.2.1 General Characteristics of Boron and Boranes 2539.2.2 Bond Length and Strengths 2549.2.3 Characterization 2559.2.4 Lewis Acidity of (Organo)Borane 2559.3 Et3B-Mediated ROP of Epoxides 2569.3.1 Introduction of ROP of Epoxides 2569.3.2 Et3B -Based Binary Lewis Pair Systems in the ROP of Epoxides 2589.3.3 Mechanism of Et3B Mediated ROP of Epoxides 2609.3.4 Poly(alkylene oxide) Structures: Novel and Innovative Polyether Architectures 2619.4 Modified Organoborane Mediated ROP of Epoxides 2649.4.1 One-Component Ammonium Borane-Based Lewis Pair Systems Mediated ROP of Epoxides 2659.4.2 One-Component Phosphonium Borane-Based Lewis Pair Systems Mediated ROP of Epoxides 2699.4.3 Silicon-Based Borane Lewis Pair System 2729.4.4 Macromolecular Organoborane Mediated ROP of Epoxides 2729.4.5 Poly(alkylene oxide) Structures: Innovative Polyether Architectures 2749.5 Chiral Organoborane Mediated Asymmetric ROP of Epoxides 2799.6 Conclusion and Outlook 281References 28310 Organocatalyst for Ring-Opening Polymerization of Cyclosiloxanes Toward Polysiloxanes 289Na Zhao, Yuetao liu, and Zhibo li10.1 Introduction 28910.2 Anionic ROP of Cyclosiloxanes 29110.3 Phosphazene-Catalyzed Anionic ROP of Cyclosiloxanes 29110.3.1 Schwesinger’s Phosphazene Bases 29310.3.2 Phosphazenium Hydroxide P5OH 29310.3.3 Cyclic Trimeric Phosphazene Base (CTPB) 29510.3.4 Trisphosphazene Base – C3N3 -Me-P3 29710.3.5 Guanidinophosphazene – HTGCP 29710.4 Guanidines-Catalyzed Anionic ROP of Cyclosiloxanes 29710.5 Phosphorus Ylides-Catalyzed Anionic ROP of Cyclosiloxanes 30210.6 NHC-Catalyzed Anionic ROP of Cyclosiloxanes 30310.7 Conclusion 304References 30511 Organic Lewis Pair in Polymer Synthesis 309Mingqian Wang, Zhiqiang Ding, Bin Wang, and Yuesheng li11.1 Lewis Pair Catalytic Ring-Opening Polymerization of Cyclic Esters 30911.2 Mechanisms for Lewis Pair-Catalyzed ROP of Cyclic Esters 31011.3 Lewis Pairs Used for ROP of Cyclic Ester 31111.3.1 Organoboron-Based Lewis Pair 31111.3.2 Organoaluminum-Based Lewis Pair 31311.3.3 Organozinc-Based Lewis Pair 31511.3.4 Metal Halide-Based LPs 318References 32212 Organocatalysts for Radical Polymerization 325Chenyu Wu, Qiang Ma, Baoshan Hou, Zhilei Wang, Zikuan Wang, and Saihu Liao12.1 Photocontrolled Organocatalyzed Radical Polymerization 32512.2 Organocatalyzed Atom Transfer Radical Polymerization (O-ATRP) 32812.2.1 Mechanism of O-ATRP 32812.2.2 Polynuclear Aromatic Hydrocarbons 32812.2.3 Phenothiazine Derivatives 32912.2.4 Dihydrophenazine Derivatives 33012.2.5 Phenoxazine Derivatives 33112.2.6 Dimethylacridine Derivatives 33212.2.7 Organic Donor–Acceptor Scaffolds 33312.2.8 Heteroatom-Doped Anthanthrene Derivatives 33412.2.9 Other Classes 33512.3 Photoinduced Electron/Energy Transfer Reversible Addition-Fragmentation Chain Transfer (PET-RAFT) 33712.3.1 Mechanism of PET-RAFT 33712.3.2 Porphyrin Derivatives 33812.3.3 Fluorescein Derivatives 34012.3.4 Phthalocyanine Derivatives 34012.3.5 Other Classes 34012.4 Structure-Property-Performance Relationships 34112.4.1 Structure–Property-Relationships 34112.4.2 Photon Absorption 34212.4.2.1 Theory for Absorption Spectrum 34212.4.2.2 Full Width at Half Maximum 34312.4.2.3 Maximum Absorption Wavelength 34412.4.2.4 Molar Extinction Coefficient 34412.4.3 Excited-State Evolution 34612.4.3.1 Quantum Yield for Long-Lived State 34612.4.3.2 Theory for Fluorescence 34712.4.3.3 Theory for Internal Conversion 34812.4.3.4 Theory for Intersystem Crossing 34912.4.4 Activation 35012.4.5 Deactivation 35212.4.6 Property-Performance Relationships 35312.5 Outlook 354References 35513 Organocatalyst-Catalyzed Non-Radical Photopolymerizations 365Yun Liao and Saihu Liao13.1 Introduction 36513.2 Organocatalysts for Photocontrolled Cationic Polymerization 36613.3 Organocatalysts for Photocontrolled Ring-Opening Polymerization 37713.4 Organocatalysts for Photocontrolled Ring-Opening Metathesis Polymerization (ROMP) 38413.5 Organocatalysts for Photocontrolled Step-Growth Polymerization 387References 39214 Enzyme-Catalyzed Controlled Radical Polymerization 399Ruoyu Li and Zesheng An14.1 Introduction 39914.2 Enzymatic Deoxygenation in RAFT Polymerization 40014.3 Enzymatic Initiation of RAFT Polymerization 40314.4 Enzymatic Deoxygenation in ATRP 40714.5 Enzyme-Catalyzed ATRP 40814.6 Conclusions 411Acknowledgments 411References 41115 Organocatalyst-Catalyzed Degradation of Polymers 419Ge Yang and Zhibo li15.1 Introduction 41915.2 Chemical Degradation of Functional Polymers 42015.2.1 Organic Bases and Organic Acids 42015.2.2 Lonic Liquids and Acid–Base Salts 42315.3 Photocatalytic Degradation of Non-Functional Polymers 42615.4 Conclusion 427References 429Index 433