Biodegradable Polymers in the Circular Plastics Economy

Biodegradable Polymers in the Circular Plastics Economy A comprehensive overview of the burgeoning field of biodegradable plastics As the lasting impact of humanity’s reliance on plastics comes into focus, scholars have begun to seek out solutions to plastic litter. In Biodegradable Polymers in the Circular Plastics Economy, an accomplished team of researchers delivers a focused guide (1) to understand plastic degradation and its role in waste hierarchy besides recycling, and (2) to create and use biodegradable plastics where appropriate. Created preferably from renewable resources, these eco-friendly polymers provide an opportunity to create sustainable and lasting solutions to the growing plastic-driven pollution problem. The broad approach to this handbook allows the authors to cover all aspects of these emerging materials, ranging from the problems present in the current plastics cycle, to the differences in type, production, and chemistry available within these systems, to end-of-life via recycling or degradation, and to life-cycle assessments. It also delves into potential commercial and policy issues to be addressed to successfully deploy this technology. Readers will also find: A thorough introduction to biodegradable polymers, focusing not only on the scientific aspects, but also addressing the larger political, commercial, and consumer concerns Mechanisms of biodegradation and the environmental impact of persistent polymers An in-depth discussion of degradable/hydrolysable polyesters, polysaccharides, lignin-based polymers, and vitrimers Management of plastic waste and life cycle assessment of bio-based plastics Biodegradable Polymers in the Circular Plastics Economy is the perfect overview of this complicated but essential research field and will appeal to polymer chemists, environmental chemists, chemical engineers, and bioengineers in academia and industry. The book is intended as a step towards a circular plastics economy that relies heavily on degradable plastics to sustain it.

Table of Contents:
Preface xv 1 Biodegradable Polymers – A Tutorial for a Circular Plastics Economy 1 Jean-Paul Lange, Michiel Dusselier, and Stefaan De Wildeman 1.1 Context 1 1.2 Plastics in the Environment – Biodegradation and Impact of Litter 4 1.3 Biodegradable Polymers 5 1.3.1 Polyesters 6 1.3.2 Polysaccharides 8 1.3.3 Lignin 9 1.3.4 Vitrimers – Recyclable Thermosets 9 1.4 Beyond Biodegradation 10 1.4.1 Recycling and End-of-Life 10 1.4.2 Lca 11 1.4.3 Implementing the “New Plastics Economy” 11 1.5 Conclusions and Outlook 12 References 15 2 Fundamentals of Polymer Biodegradation Mechanisms 17 Ebin Joseph, Payman Tohidifar, Cara T. Sarver, Roderick I. Mackie, and ChristopherV.Rao 2.1 Introduction 17 2.2 Overall Scheme of Polymer Degradation 19 2.3 Biodegradation of Polysaccharides 20 2.3.1 Cellulose 20 2.3.2 Starch 22 2.4 Biodegradation of Polyamides 24 2.5 Biodegradation of Polyesters 24 2.5.1 Polylactic Acid 25 2.5.2 Poly(ε-caprolactone) 27 2.5.3 Polyhydroxyalkanoates 28 2.5.4 Polyethylene Terephthalate 29 2.6 Biodegradation of Hydrocarbons 36 2.6.1 Polyethylene 36 2.6.2 Polypropylene 38 2.6.3 Polystyrene 39 2.7 Biodegradation of Halogenated Polymers 40 2.7.1 Polyvinyl Chloride 41 2.7.2 Polytetrafluoroethylene 41 2.8 Biodegradation of Polyethers 41 2.8.1 Polyethylene Glycol 41 2.8.2 Polyurethane 42 2.9 Application of Biodegradation 43 2.10 Current Challenges and Future Prospects for Biodegradation of Plastics Wastes 44 2.a Detailed Mechanism of PET Hydrolysis 45 References 46 3 Plastic Pollution. The Role of (Bio)Degradable Plastics and Other Solutions 59 Lei Tian, Robert-Jan van Putten, and Gert-Jan M. Gruter 3.1 Introduction and Problem Definition 59 3.2 Sources of Macroplastics and MNPs 61 3.2.1 Mismanagement of Waste 61 3.2.2 Accidental Release 64 3.2.3 MNPs in Products 64 3.2.4 Degradation of Outdoor Objects 64 3.2.5 Wear (Tires, Clothing) 65 3.2.6 Waste and Wastewater Management (Water/Wind) 66 3.3 Impacts of Macroplastics and MNPs 67 3.3.1 Ecological Impact of Macroplastics (Entanglement and Ingestion) 67 3.3.2 Economic Impact of Macroplastics 67 3.3.3 Ecological Impacts of MNPs 68 3.3.3.1 Aquatic Environment 68 3.3.3.2 Terrestrial Environment 69 3.3.3.3 Atmosphere 69 3.3.4 Threat to Human Health 70 3.3.4.1 MNPs in the Human Food Chain 70 3.3.4.2 Plastic-Related Contaminants 70 3.3.4.3 Other Contaminants 70 3.3.5 Socio-Economic Impacts of MNPs 71 3.4 Plastic Biodegradability 71 3.5 Solutions 72 3.5.1 Cleaning Up 72 3.5.2 Waste Mitigation 73 3.5.3 Material Design 73 3.5.4 Bringing It All Together 73 3.5.5 Policies and Legislation 76 3.6 Conclusions 77 References 78 4 Tutorial on Polymers – Manufacture, Properties, and Applications 83 Gert-Jan M. Gruter and Jean-Paul Lange 4.1 Introduction 83 4.1.1 Today’s Petrochemical Industry 83 4.1.2 Today’s Bio-based Plastic Industry 85 4.1.3 Environmental and Climate Challenges 85 4.2 Production of Polymers 86 4.2.1 Addition Polymers 87 4.2.2 Condensation Polymers 88 4.2.3 Thermosets 90 4.2.4 Renewable Monomers 91 4.2.4.1 Oils-Based Monomers 91 4.2.4.2 Sugar-Based Monomers 92 4.2.4.3 Lignocellulose-Based Monomers 93 4.2.4.4 CO 2 -Based Monomers 95 4.3 Main Polymers Applications 95 4.3.1 Rigids 97 4.3.2 Films 98 4.3.3 Fibers 98 4.3.4 Foams 99 4.3.5 CASE (Coatings, Adhesives, Sealants, Elastomers) 100 4.3.6 Composites 102 4.4 End-of-Life and Biodegradation 103 4.4.1 Reuse and Recycling 103 4.4.2 Biodegradation 103 4.5 Conclusions 105 4.a Definitions: Biopolymer vs. Bio-based Polymer and Relation to Biodegradation 105 List of Polymers 107 References 108 5 Condensation Polyesters 113 Jules Stouten and Katrien V. Bernaerts 5.1 Introduction 113 5.2 Preparative Methods 114 5.3 Biodegradation of Polyesters 116 5.3.1 Hydrolytic Degradation 117 5.3.2 Enzymatic Degradation 118 5.4 Aliphatic Polyesters 119 5.4.1 Poly(alkylene dicarboxylates) 119 5.4.2 Poly(hydroxy acids) 120 5.4.3 Cyclic Sugar-Based Monomers 121 5.5 Semi-aromatic Polyesters 122 5.5.1 Poly(butylene adipate terephthalate) (PBAT) 122 5.5.2 Furanoate Copolymers 124 5.6 Cross-linked Polyesters 127 5.6.1 Multifunctional Alcohols or Carboxylic Acids 127 5.6.2 Incorporation of Functional Monomers 129 5.6.3 Cross-linking of Native Polyesters 130 5.7 Applications for Biodegradable Condensation Polyesters 130 5.7.1 Biomedical Applications 131 5.7.2 Agricultural Applications 132 5.7.3 Packaging Material 132 5.8 Polyester Recycling 132 5.9 Concluding Remarks 134 References 135 6 Polyhydroxyalkanoates (PHAs) – Production, Properties, and Biodegradation 145 Martin Koller and Anindya Mukherjee 6.1 Introduction 145 6.1.1 General Aspects of Biodegradation of Polymers 147 6.1.2 General Aspects of Microbial Synthesis of PHAs 148 6.1.3 Types and Properties of PHAs 150 6.2 Biosynthesis – Substrates and Strains 152 6.2.1 Principle Stoichiometry of PHA Biosynthesis 152 6.2.2 Biosynthesis of scl- and mcl-PHAs 154 6.2.3 Heterotrophic Feedstocks 155 6.2.4 Autotrophic Feedstocks 157 6.2.5 Syngas 158 6.2.6 Methane 158 6.2.7 Production Strains 160 6.3 Bioengineering: Bioreactor Design and Feeding Regime 163 6.3.1 Feeding Regime 163 6.3.2 Continuously Operated Bioreactors for Liquid Feed 164 6.3.3 Bioreactors for Gas Feed 166 6.3.4 Photo-reactors for CO 2 Feed 166 6.4 Downstream Processing for PHA Recovery 167 6.4.1 Classical Solvents 168 6.4.2 Halogen-Free Solvents 170 6.4.3 Supercritical Solvents 172 6.4.4 Recovery by Chemical and Mechanical Disintegration of Biomass 173 6.4.5 Biological PHA Recovery 175 6.5 End-of-Life Options: Recycling and Biodegradation of PHAs 176 6.5.1 Recycling 176 6.5.2 Incineration 178 6.5.3 Mechanistic Considerations of PHA Degradation 178 6.6 Biodegradation – Added Value for Selected Applications 181 6.6.1 Packaging 181 6.6.2 Hygiene/Care/Cosmetics 182 6.6.3 Medical – Drug Delivery 182 6.6.4 Other Applications 184 6.7 Conclusions 185 References 186 7 Ring-Opening Polymerization Strategies for Degradable Polyesters 205 An Sofie Narmon, Liliana M. Jenisch, Louis M. Pitet, and Michiel Dusselier 7.1 Introduction 205 7.2 Ring-Opening Polymerization Mechanisms 207 7.2.1 Cationic Ring-Opening Polymerization 207 7.2.2 Anionic Ring-Opening Polymerization 209 7.2.3 Coordination–Insertion Ring-Opening Polymerization 210 7.2.4 Enzymatic Ring-Opening Polymerization 211 7.3 ROP-Based Polyesters 211 7.3.1 Lactones 211 7.3.2 Thermodynamics and Kinetics 212 7.3.3 Functionalization 214 7.3.3.1 ROP of Functional Lactones 215 7.3.3.2 Post-polymerization Functionalization 215 7.3.3.3 Grafting 216 7.3.4 Four-Membered Lactones 216 7.3.4.1 β-Butyrolactone 218 7.3.4.2 Acid-Substituted β-Lactones (β-Malolactonate) 218 7.3.4.3 Alkoxy-Substituted β-Lactones 219 7.3.4.4 Alkene-Substituted β-Lactones 220 7.3.5 Five-Membered Lactones 221 7.3.5.1 γ-Butyrolactone 221 7.3.5.2 α-Angelicalactone 223 7.3.5.3 α-Methylene-γ-Butyrolactone 223 7.3.5.4 Ether γ-Lactones 225 7.3.6 Six-Membered Lactones 227 7.3.6.1 δ-Valerolactone 227 7.3.6.2 Unsaturated δ-Lactones 227 7.3.6.3 Ester-Substituted δ-Lactones 228 7.3.6.4 Ether δ-Lactones 230 7.3.6.5 Dilactones 232 7.3.7 Seven-Membered Lactones 236 7.3.7.1 ε-Caprolactone 236 7.3.7.2 Substituted and Functionalized ε-Caprolactone 238 7.3.7.3 Ether-ε-Lactones 241 7.4 Relations Between ROP Polymers and Degradability 242 7.5 Conclusion 246 7.6 Outlook and Recommendations 249 References 252 8 Recent Developments in Biodegradable Cellulose-Based Plastics 273 Karin Molenveld and Ted M. Slaghek 8.1 General Introduction 273 8.2 Cellulose 274 8.3 The Development of Cellulose Plastics 275 8.3.1 Cellulose Feedstock and Dissolving Pulp 276 8.3.2 Cellulose Derivatization 276 8.3.3 Cellulose Acetate and Cellulose Esters 277 8.3.4 Cellophane 279 8.3.5 Cellulose Fibers in Thermoplastic Formulations 280 8.4 Recent Developments in Thermoplastic Cellulose Derivatives 280 8.4.1 Characterization Methods for Lignocellulosic Biomass 281 8.4.2 Alternative Feedstocks for Dissolving Pulp and Production Routes 282 8.4.3 Ionic Liquids and Deep Eutectic Solvents for Cellulose Regeneration and Modification 283 8.4.4 New Derivatization Routes 284 8.4.5 Plasticizers 284 8.4.6 Mixed Cellulose Esters 285 8.4.7 Cellulose–Polymer Blends 286 8.4.8 (New) Properties and Processing Routes 287 8.4.9 New Applications 287 8.5 Biodegradation of Cellulose Derivatives 288 8.6 Conclusions 289 References 290 9 Ester Derivatives of Microbial Synthetic Polysaccharides 299 Hakyong Lee, Hongyi Gan, Azusa Togo, Yuya Fukata, and Tadahisa Iwata 9.1 Introduction 299 9.1.1 Background of Bio-Based Plastics 299 9.1.2 Polysaccharides 300 9.2 Zero Birefringence Property of Pullulan Esters 302 9.3 Bio-Based Adhesives from Dextran (α-1,6-Glucan) 304 9.4 Films and Fibers from Paramylon and Curdlan (β-1,3-Glucan) Esters 306 9.5 Polymerization of α-1,3-Glucan and Films of α-1,3-Glucan Esters 310 9.6 High-Performance Polysaccharide-Branched Esters 312 9.6.1 Cellulose-Branched Esters [14] 312 9.6.2 β-1,3-Glucan (Curdlan) Branched Esters [15] 314 9.6.3 α-1,3-Glucan-Branched Esters [16] 315 9.7 Enzymatic Esterification of Polysaccharides 316 9.7.1 Enzymes as Biocatalysts 317 9.7.2 Reaction Mechanism 318 9.7.3 Factors Influencing Enzyme Activity 319 9.7.4 Strategies for Efficient Biocatalyst Processes 320 9.7.5 Development Trend and Prospects 320 9.8 Biodegradation of Polysaccharide Ester 322 9.9 Summary 322 References 322 10 Biodegradable Lignin-Based Plastics 329 Yi-ru Chen and Simo Sarkanen 10.1 Lignocellulose Biorefineries 329 10.2 Macromolecular Lignin Configuration 331 10.3 Industrial Availability of Lignins 336 10.4 Compelling Traits in Physicochemical Behavior of Kraft Lignin Species 337 10.5 Kraft Lignin-Based Plastics 341 10.6 Tuning Strength and Production Cost of Plastics with High Kraft Lignin Contents 343 10.7 Ligninsulfonates (Lignosulfonates) 346 10.8 Laboratory Ball-Milled Lignins 348 10.9 Blend Configuration in Ball-Milled Lignin-Based Plastics Exemplifies the General Case 351 10.10 Lignin–Lignin Blends 355 10.11 Biodegradation of Kraft Lignin-Based Plastics 357 10.12 Alternative Formulations for Polymeric Materials Containing More than 50 wt% Lignin 359 10.13 Concluding Remarks 362 Acknowledgments 362 References 363 11 Design of Recyclable Thermosets 369 Bryn D. Monnery, Apostolos Karanastasis, and Louis M. Pitet 11.1 Introduction 369 11.1.1 Polymers and Plastics 369 11.1.2 Handling of Plastic Waste 370 11.1.3 Chemical Nature of Plastics 370 11.2 Design of Recyclable Thermosetting Polymers 372 11.2.1 Recyclability by Triggered Degradation 374 11.2.2 Dissociative Covalent Adaptive Networks 374 11.2.3 Vitrimers (Associative CANs) 376 11.3 Examples of Vitrimers 380 11.4 Adaptable Cross-Linking of Conventional Polymers 383 11.5 Outlook and Summary 385 References 387 12 Managing Plastic Wastes 391 Jean-Paul Lange 12.1 Introduction 391 12.2 Plastic Waste 391 12.3 Mechanical Recycling 393 12.4 Dissolution/Precipitation 394 12.5 Chemical Recycling 395 12.5.1 Depolymerization of Condensation Polymers 396 12.5.2 Melt Pyrolysis of Polyolefins 397 12.5.3 Alternative Pyrolysis Processes 398 12.6 Energy Recovery – Recycle Fuels and Incineration 400 12.7 Waste Destruction – Biodegradation 401 12.8 Life Cycle Analyses 401 12.9 Need for Fresh Carbon Input 402 12.10 Conclusion and Outlook 403 References 404 13 Life Cycle Assessment of Bio-Based Plastics: Concepts, Findings, and Pitfalls 409 li Shen 13.1 Introduction and Chapter Learning Objectives 409 13.2 “Bioplastics” Is a Confusing Term 409 13.3 LCA in a Nutshell 412 13.3.1 Concept and a Brief History 412 13.3.2 Procedure, Jargons, and Sciences Behind 413 13.3.2.1 Goal and Scope Definition 414 13.3.2.2 Life Cycle Inventory Analysis (LCI) 414 13.3.2.3 Life Cycle Impact Assessment (LCIA) 415 13.3.2.4 Interpretation 416 13.4 LCA Case Studies of Seven Single-Use Plastic Items Made from Bio-Based Resources: Highlights and Lessons Learned 417 13.4.1 Background, Aim, and Scope of the BIO-SPRI Study 417 13.4.2 Key Findings 419 13.4.2.1 Biomass Feedstock Acquisition 421 13.4.2.2 Manufacturing Phase: From Biomass to Polymers, Materials, and End Products 426 13.4.2.3 Distribution to End User: Impacts from Transportation 427 13.4.2.4 End-of-Life (EoL) Post-consumer Waste Management Scenarios 427 13.4.3 Comparisons with Petrochemical Plastics 431 13.5 Lessons Learned from the Case Studies and Looking Forward to a Circular Bio-Based Economy 432 13.a General Structure of Classification and Characterization in LCIA, using the example of 16 Impact Categories Recommended by the EC EF (Environmental Footprint) Impact Assessment Methods 434 13.b Normalization and Weighting Factors Recommended by the EF (Environmental Footprint) Method [12, 19, 46], Latest Update: May 2020 436 References 436 14 How to Create “A New Plastics Economy”? Marketing Strategies and Hurdles – Finding Application Niches 441 Sil Nevejans and Stefaan De Wildeman 14.1 Introduction 441 14.2 Stories from the Past 442 14.2.1 Polyhydroxyalkanoates (PHAs) 442 14.2.2 Polylactic Acids (PLA) 443 14.2.3 Polyethylenefuranoates (PEF) 444 14.3 Greenwashing vs. Growing Pains 444 14.4 From Idea to Product: “Technical Readiness Levels” 445 14.4.1 Defining the Technical Readiness Levels 445 14.4.2 Application of the TRLs 447 14.4.3 Product(ion) Validation 449 14.5 Five Innovation Rules to Create “A New Plastics Economy” 449 14.5.1 Target Small-Volume, High-Value Applications to Open New Market Space 450 14.5.2 Time Right Instead of Fast 451 14.5.3 Go Local 452 14.5.4 Take Risks 453 14.5.5 Go “Green” 454 14.6 Conclusion 455 References 456 Index 457

About the Author :
Michiel Dusselier is tenure track professor at KU Leuven, Belgium, in the faculty of Bioscience Engineering. He co-founded the Center for Sustainable Catalysis and Engineering (CSCE), where he explores zeolite synthesis, reactor design, functional biodegradable plastics, and heterogeneous catalysis (CO2 activation). He has co-authored over 60 peer-reviewed papers, 7 patents, and 8 book chapters. Jean-Paul Lange is senior principal science expert at Shell in Amsterdam, The Netherlands, and professor at the University of Twente, The Netherlands, where he is exploring novel catalytic processes for producing fuels and chemicals from natural gas,oil, biomass, and waste plastic. He is co-author of 100 patents, 70 papers, and 7 book chapters.