Recycling of Polymers: Methods, Characterization and Applications

Recycling of Polymers This timely reference on the topic is the only book you need for a complete overview of recyclable polymers. Following an introduction to various polymer structures and their resulting properties, the main part of the book deals with different methods of recycling. It discusses in detail the recycling of such common polymers as polyethylene, polypropylene and PET, as well as rubbers, fibers, engineering polymers, polymer blends and composites. The whole is rounded off with a look at future technologies and the toxicological impact of recycled polymers. An indispensable reference source for those working in the field, whether in academia or industry, and whether newcomers or advanced readers.

Table of Contents:
Preface XI List of Contributors XV Abbreviations XVII 1 Introduction 1 Raju Francis, Geethy P. Gopalan, and Anjaly Sivadas 1.1 Introduction 2 1.1.1 Why Recycling? 2 1.1.2 Sources ofWaste 2 1.1.3 Plastics 3 1.1.4 Recycling of Plastics 3 1.1.5 Municipal SolidWaste 4 1.1.6 Various Stages of Recycling PlasticWastes 6 1.1.7 Additives 6 1.1.8 Mixed Plastics 8 1.1.9 Composites 8 1.2 Conclusion 8 References 9 2 Common Additives used in Recycling of Polymers 11 2.1 Review on Different Additives Used in Polymer Recycling 11 Sivasankarapillai Vishnu Sankar and Sivasankarapillai Anil Kumar 2.1.1 Introduction 11 2.1.1.1 Challenges in Recycling – Need for Additives 11 2.1.1.2 Equipment for Additive Processing 12 2.1.2 Different Types of Additives 12 2.1.2.1 Stabilizing Agents 14 2.1.2.2 Compatibilizers 19 2.1.2.3 Antioxidants 21 2.1.2.4 Impact Modifiers 23 2.1.2.5 Fillers and Modifiers 25 2.1.2.6 Antistatic Agents 26 2.1.2.7 Coloring Agents 26 2.1.2.8 Flame Retardants 27 2.1.2.9 Lubricants 28 2.1.2.10 Plasticizers 28 2.1.2.11 Antibacterial or Antimicrobial Additives 29 2.1.2.12 Coupling Agents 29 2.1.3 Conclusion 30 References 30 2.2 Recent Trends and Future of Polymer Additives in Macromolecular Recycling Technology: A Brief Overview 31 Sivasankarapillai Vishnu Sankar and Sivasankarapillai Anil Kumar 2.2.1 Introduction 31 2.2.2 Miscellaneous Additives 32 2.2.2.1 Nucleating Agents 32 2.2.2.2 Reinforcing Agents or Fillers 33 2.2.2.3 Optical Brighteners 36 2.2.2.4 Surface Improvers 37 2.2.2.5 Antiblocking Additives 39 2.2.2.6 Blowing Agents (Foaming Agents) 39 2.2.2.7 Antifogging Agents 41 2.2.3 New Trends in Additives Technology 43 2.2.3.1 Advances in Stabilizers 46 2.2.3.2 Advances in Flame Retardants (FRs) 46 2.2.3.3 Advances in Plasticizers 47 2.2.3.4 Advances in Coloring Agents 47 2.2.3.5 Advances in Fillers 48 2.2.3.6 Advances in Other Additive Classes 48 2.2.3.7 Multifunctional Additives 49 2.2.4 Conclusion 49 References 50 3 Methods of Recycling 55 3.1 Methods of Recycling of Polymers: Addition Polymers 55 Beena Sethi 3.1.1 Introduction 55 3.1.2 Primary Recycling 58 3.1.3 Mechanical Recycling (or Secondary Recycling) 58 3.1.4 Chemical or Feedstock Recycling (Tertiary Recycling) 59 3.1.5 Energy Recovery (Quaternary Recycling) 60 3.1.6 Chemical Recycling of Polyethylene (LDPE and HDPE) 62 3.1.6.1 Introduction 62 3.1.6.2 Thermolysis Schemes and Technologies 63 3.1.6.3 Reactor Types 65 3.1.7 Polyolefin Thermal Cracking 66 3.1.7.1 Catalytic Degradation 66 3.1.8 Chemical Recycling of Polypropylene 67 3.1.8.1 Introduction 67 3.1.8.2 Pyrolysis 69 3.1.8.3 Co-pyrolysis 70 3.1.8.4 Catalytic Cracking 71 3.1.9 Chemical Recycling of Polystyrene 75 3.1.9.1 Introduction 75 3.1.9.2 Recycling Methods for Polystyrene Products 76 3.1.9.3 Future Prospects 83 3.1.10 Chemical Recycling of Poly(vinyl chloride) 83 3.1.10.1 Introduction 83 3.1.10.2 Mixed Plastic Recycling Processes 86 3.1.10.3 Mixed PVCWastesWorld Initiatives 88 3.1.10.4 The BASF Feedstock Recycling Process 88 3.1.10.5 Veba Combi Cracking Process 90 3.1.11 Chemical Recycling of Poly(methyl methacrylate) 90 3.1.11.1 Introduction 90 3.1.11.2 Dissolution/Reprecipitation 91 3.1.11.3 Chemical/Feedstock Recycling 92 References 93 3.2 Methods of Recycling of Polymers: Condensation Polymers 101 Beena Sethi 3.2.1 Introduction 101 3.2.2 Chemical Recycling of Nylon 101 3.2.2.1 Introduction 101 3.2.2.2 Recycling Methods 101 3.2.3 Chemical Recycling Involving Depolymerization of NylonsWhich Can Be Carried Out by Hydrolysis or Ammonolysis of Nylon 6,6 and Nylon 6 102 3.2.3.1 Hydrolysis of Nylon 6 102 3.2.3.2 Hydrolysis of Nylon 6,6 and Nylon 4,6 103 3.2.3.3 Ammonolysis of Nylon 6,6 103 3.2.3.4 Recovery of Nylon 6,6 Monomers 104 3.2.3.5 Catalytic Pyrolysis 105 3.2.3.6 Applications of Depolymerized Nylon 6 105 3.2.4 Chemical Recycling of Polycarbonate 105 3.2.4.1 Introduction 105 3.2.4.2 Recycling Techniques 106 3.2.5 Advantages of Recycling and Reuse of Polymers 110 References 112 4 Recycling of Plastics 115 Preetha Balakrishnan and Meyyappallil Sadasivan Sreekala 4.1 Introduction 115 4.2 PlasticWaste Management Scenario 117 4.3 Ways of Recycling 119 4.3.1 Reuse 120 4.3.2 Mechanical Recycling 121 4.3.3 Chemical Recycling 121 4.4 Poly(Lactic Acid) 122 4.5 Poly(Vinyl Chloride) 125 4.6 Polyethylene 126 4.7 Polypropylene 128 4.8 Polystyrene 129 4.9 Poly(Ethylene Terephthalate) (PET) 129 4.10 Applications 134 References 135 5 Recycling of Rubber 141 Valiya Parambath Swapna and Ranimol Stephen 5.1 Introduction 141 5.2 Rubber 142 5.3 Recycling of Rubber Products 143 5.3.1 Chemical Process 143 5.3.2 Physical Methods 145 5.3.2.1 Mechanochemical Techniques 145 5.3.2.2 Microwave Technique 146 5.3.2.3 Ultrasonic Technique 146 5.3.2.4 Twin-Screw Extruder 148 5.3.3 Biological Process 148 5.4 Applications of Recycled Rubber 152 5.4.1 Sound-Insulation Materials 152 5.4.2 Civil Engineering Applications 153 5.4.3 Oil Absorbent 154 5.4.4 Energy Production 154 5.4.5 Zinc Fertilizer 155 5.5 Concluding Remarks 155 References 156 6 Fibers 163 Raju Francis, Nidhin Joy, Anjaly Sivadas, and Geethy P. Gopalan 6.1 Introduction 163 6.2 Natural Fibers 164 6.2.1 Kenaf 165 6.2.2 Cotton 167 6.2.3 Sisal 170 6.2.4 Asbestos 174 6.3 Synthetic Fibers 176 6.3.1 Nylon 177 6.3.2 Polyester 182 6.3.3 Glass Fiber 187 6.3.3.1 Glass Fiber-Reinforced Plastics 188 6.3.3.2 Mechanical Process 188 6.3.3.3 Thermal Process 188 6.3.3.4 Chemical Recycling 190 6.3.4 Carbon Fiber 192 6.3.4.1 Mechanical Recycling 192 6.3.4.2 Thermal Recycling 193 6.3.4.3 Chemical Recycling 195 6.4 Conclusion 198 References 198 7 Recycling of Polymer Blends and Composites (Epoxy Blends) 209 Jyothi V. Sunny 7.1 Introduction 209 7.2 Polymer Blends and Composites 209 7.2.1 Methods of Recycling 213 7.2.1.1 Mechanical Recycling 213 7.2.1.2 Chemical Recycling 215 7.2.1.3 Thermal Recycling 216 7.3 Characterization and Application of Recyclates 218 7.4 Conclusions 219 References 219 8 Recycling of Other Layered Mixed Plastics or Resins: Polyurethanes 223 Jyothi V. Sunny 8.1 Introduction 223 8.2 Mechanical Recycling 226 8.3 Chemical Recycling 227 8.3.1 Glycolysis 228 8.3.2 Hydrolysis 229 8.3.3 Aminolysis 229 8.4 Thermochemical methods 230 8.4.1 Pyrolysis 230 8.4.2 Gasification 230 8.4.3 Hydrogenation 230 8.5 Energy Recovery by Incineration 231 References 232 9 Ecoprofiles of Recycled Polymers at a Glance 235 9.1 Advantages of Recycled Polymers on the Environment 235 Raju Francis and Anjaly Sivadas 9.1.1 Introduction 235 9.1.2 Poly(ethylene terephthalate) (PET) 236 9.1.3 High-Density Polyethylene (HDPE) 237 9.1.4 Poly(vinyl chloride) (PVC) 239 9.1.5 Polypropylene (PP) 240 9.1.6 Polystyrene (PS) 241 9.1.7 Other Polymers 242 9.1.8 Conclusion 245 References 245 9.2 Toxic or Environmental Effects of Recycled Polymers 248 Raju Francis, Nidhin Joy, and Anjaly Sivadas 9.2.1 Introduction 248 9.2.2 Will Recycling Reduce the Amount ofWaste? 249 9.2.2.1 Recycling ofWaste Electrical and Electronic Equipment (WEEE) 250 9.2.2.2 Recycling of Tires 251 9.2.2.3 Recycling of Plastics 251 9.2.2.4 Recycling of Polymers 251 9.2.2.5 Health Problems 252 9.2.2.6 Recycling by Polymer Incineration 252 9.2.3 Conclusion 253 References 253 Index 257

About the Author :
Raju Francis is associate professor at Mahatma Gandhi University, Kottayam, India. He obtained his PhD degree in chemistry from NIIST (RRL-T), University of Kerala, India, in 1998 and completed his postdoc at the University of Bordeaux, France, and at the University of Florida, USA. He was an exchange visitor at Toyo University, Japan, and at King Abdullah University of Science & Technology, Saudi Arabia. His research interests include polymer-synthesis and applications, hybrid materials and environmental chemistry.