Advanced Green Composites

Most composites, particularly those made using thermoset resins, cannot be recycled or reused. As a result, most of them end up in landfills at the end of their useful life which is neither sustainable nor environment-friendly. Various laws enacted by Governments around the world and heightened global awareness about sustainability and global warming is changing this situation. Significant research is being conducted in developing and utilizing sustainable fibers and resins, mostly derived from plant, to fabricate 'Green' composites. The significant progress in the past 20 or so years in this field has led to the development of green composites with high strength or so called Advanced Green Composites. More interestingly, green composites have also acquired various different properties such as fire resistance, transparency, barrier to gases and others. The term 'advanced' which only included high strength and stiffness now includes all these special properties. The world is on the cusp of a major change, and once fully developed, such composites could be used in applications ranging from automobiles to sporting goods, from circuit boards to housing and from furniture to packaging. This book, by presenting the state-of-the-art developments in many aspects of advanced green composites adds significantly to the knowledge base that is critical for their success of expanding their use in applications never seen before. The chapters are written by world?s leading researchers and present in-depth information in a simple way.

This provides readers and researchers the latest developments in the field of 'Green' resins (with ways of strengthening them), High Strength Green Fibers (including micro and nano-cellulose fibrils/fibers) and Green Composites in the first few chapters. The introductory chapter summarizes the consequences of using conventional, petroleum-based materials and the need for green composites as well as the progress being made in this field. After that the book delves in to Advanced Green Composites in a broader sense and includes chapters on High Strength Green Composites, Self-healing Green Composites, Transparent Green Composites, All-cellulose composites, Toughened Green Composites, Green Biofoams, Bioinspired Shape Memory Composites, etc. The chapters are written by the experts who are highly respected in their fields.

Preface xiii

1 Introduction 1
Anil N. Netravali

1.1 Introduction 2

2 Green Resins from Plant Sources and Strengthening Mechanisms 11
Muhammad M. Rahman and Anil N. Netravali

2.1 Introduction 12

2.2 Green Resins from Agro-Resources 14

2.2.1 Plant Protein-Based Resins 14

2.2.2 Plant Starch-Based Resins 21

2.3 Green Resins from Microbial Fermentation 25

2.3.1 Polyhydroxyalkanoates 25

2.3.2 Pullulan 27

2.4 Green Resins Using Monomers from Agricultural Resources 29

2.4.1 Polylactic Acid 29

2.5 Strengthening of Green Resins using Nano-Fillers 32

2.5.1 Inorganic Nano-Fillers 33

2.5.2 Organic Nano-Fillers 38

2.6 Conclusions 43

References 44

3 High Strength Cellulosic Fibers from Liquid Crystalline Solutions 57
Yuxiang Huang and Jonathan Y. Chen

3.1 Introduction 57

3.2 Fibers from Liquid Crystalline Solutions of Cellulose Derivatives 59

3.3 Fibers from Liquid Crystalline Solution of Nonderivatized Cellulose 60

3.4 Regenerated-Cellulose/CNT Composite Fibers with Ionic Liquids 61

3.5 Future Prospects 63

Summary 64

References 65

4 Cellulose Nanofibers: Electrospinning and Nanocellulose Self-Assemblies 67
You-Lo Hsieh

4.1 Introduction 68

4.2 Electrospinning of Cellulose Solutions 70

4.3 Cellulose Nanofibers via Electrospinning and Hydrolysis of Cellulose Acetate 70

4.4 Bicomponent Hybrid and Porous Cellulose Nanofibers 72

4.5 Wholly Polysaccharide Cellulose/Chitin/Chitosan Hybrid Nanofibers 74

4.6 Surface-Active Cellulose Nanofibers 76

4.7 Nanocelluloses 77

4.8 Nanocelluloses from Agricultural By-Products 79

4.9 Source Effects – CNCs from Grape Skin, Tomato Peel, Rice Straw, Cotton Linter 80

4.10 Process Effect – Nanocelluloses from Single Source (Corn Cob, Rice Straw) 82

4.11 Ultra-Fine Cellulose Fibers from Electrospinning and Self-Assembled Nanocellulose 85

4.12 Further Notes on Nanocellulose Applications and Nanocomposites 87

Acknowledgement 88

References 88

5 Advanced Green Composites with High Strength and Toughness 97
Anil N. Netravali

5.1 Introduction 98

5.2 ‘Greener’ Composites 99

5.3 Fully ‘Green’ Composites 101

5.4 ‘Advanced Green Composites’ 102

5.5 Conclusions 106

References 108

6 All-Cellulose (Cellulose–Cellulose) Green Composites 111
Shuji Fujisawa, Tsuguyuki Saito and Akira Isogai

6.1 Introduction 111

 6.1.1 Cellulose 111

6.1.2 Nanocelluloses for Polymer Composite Materials 112

6.1.3 All-Cellulose Composites 114

6.2 Preparation of ACCs 114

6.2.1 Dissolution of Cellulose 114

6.2.1.1 Aqueous Solvents 114

6.2.1.2 Organic Solvents 115

6.2.1.3 Ionic Liquids 115

6.2.2 Preparation of ACCs 116

6.2.2.1 One-Phase Preparation 116

6.2.2.2 Two-Phase Preparation 116

6.3 Structures and Properties of ACCs 120

6.3.1 Optical Properties 120

6.3.2 Mechanical Properties 120

6.3.3 Thermal Expansion Behavior 124

6.3.4 Gas Barrier Properties 124

6.3.5 Biodegradability 125

6.4 Future Prospects 125

6.5 Summary 126

6.6 Acknowledgements 127

References 127

7 Self-Healing Green Polymers and Composites 135
Joo Ran Kim and Anil N. Netravali

7.1 Introduction 136

7.1.1 Self-Healing Property in Materials: What is it and Why it is Needed? 136

7.2 Types of Self-Healing Approaches Used in Thermoset Polymers 137

7.2.1 Microcapsule-Based Self-Healing System 138

7.2.1.1 Microencapsulation Techniques 139

7.2.1.2 Microcapsule Systems for Self-Healing 148

7.2.2 Vascular Self-Healing System 158

7.2.2.1 One-, Two-, or Three-Dimensional Microvascular Systems 159

7.2.3 Intrinsic Self-Healing System 161

7.2.3.1 Test Methods to Characterize Self-Healing 162

7.2.3.2 Quasi-Static Fracture Methods 163

7.2.3.3 Fatigue Fracture Methods 165

7.2.3.4 Impact Fracture Methods 166

7.2.3.5 Other Techniques 166

7.3 Self-Healing Polymers from Green Sources 167

7.3.1 Self-Healing Polymers in Biomaterials 168

7.3.2 Self-Healing Green Resins and Green Composites 170

7.4 Summary and Prospects 173

Acknowledgements 175

References 175

8 Transparent Green Composites 187
Antonio Norio Nakagaito, Yukiko Ishikura and Hitoshi Takagi

8.1 Introduction 187

8.2 Cellulose Nanofiber-Based Composites and Papers 189

8.2.1 Bacterial Cellulose-Based Composites 189

8.2.2 CNF-Based Composites 191

8.2.3 Transparent Nanopapers 194

8.2.4 All Cellulose Transparent Composites 195

8.3 Chitin-Based Transparent Composites 197

8.3.1 Chitin Nanofiber-Based Composites 197

8.3.2 Micro-Sized Chitin Composites 199

8.3.3 Chitin-Chitosan Transparent Green Composites 200

8.3.4 All Chitin Nanofiber Transparent Films 202

8.4 Electronic Devices Based on CNF Films and Composites 202

8.5 Future Prospects 205

8.6 Summary 206

References 206

9 Toughened Green Composites: Improving Impact Properties 211
Koichi Goda

9.1 Introduction 211

9.2 Significance of Fiber Length in Toughened Fibrous Composites 212

9.3 Impact Properties of Green Composites 217

9.3.1 Relation Between Interfacial and Mechanical Properties in Green Composites 217

9.3.2 A Pattern of Increase in Tensile Strength and Decrease in Impact Strength 221

9.3.3 Effect of Toughened Resin 227

9.3.4 Approaches to Increase Both TS and IS 228

9.4 Role of Large Elongation at Break in Regenerated Cellulose Fibers 229

9.5 Toughened Cellulose Fibers and Green Composites 231

9.5.1 Toughening Mechanism of Regenerated Cellulose Fibers 231

9.5.2 Mercerization Effect 234

9.5.3 Other Beneficial Chemical Treatments 238

9.6 Conclusions 240

Appendix 241

References 243

10 Cellulose Reinforced Green Foams 247
Jasmina Obradovic, Carl Lange, Jan Gustafsson and Pedro Fardim

10.1 Introduction 248

10.2 Bio-Based Foams 249

10.2.1 Starch-Based Foams 250

10.2.2 Foams Based on Vegetable Oils 253

10.2.3 Foams Based on Poly(Lactic Acid) 255

10.3 Surface Engineering of Cellulose Fibres Used in Foams 256

10.3.1 Chemical Modifications of Cellulose Fibres 257

10.3.2 In Situ Synthesis of Hybrid Fibres 258

10.3.2.1 Topology and Particle Content on Hybrid Fibres 260

10.3.2.2 Foam Formation 262

10.3.2.3 Combustion Behavior of Foams 262

10.4 Prospects 265

10.5 Summary 266

Acknowledgements 267

References 267

11 Fire Retardants from Renewable Resources 275
Zhiyu Xia, Weeradech Kiratitanavit, Shiran Yu, Jayant Kumar, Ravi Mosurkal and Ramaswamy Nagarajan

11.1 Introduction 276

11.2 Fire Retardant Additives Based on Phosphorus and Nitrogen from Renewable Resources 278

11.2.1 Nucleic Acids 279

11.2.2 Proteins Containing Phosphorus and Sulfur 286

11.2.3 Phosphorus/Nitrogen-Rich Carbohydrates 289

11.2.4 Carbohydrates 291

11.3 Natural Phenolic Compounds as Flame Retardant Additives 295

11.3.1 Lignin 296

11.3.2 Tannins 300

11.3.3 Cardanol and Polymers of Cardanol 306

11.3.4 Polydopamines 307

11.4 Other FR Materials from Renewable Sources 308

11.4.1 Chicken Eggshell 308

11.4.2 Banana Pseudostem Sap 308

11.5 Prospects 310

11.6 Summary 311

11.7 Acknowledgements 312

References 312

12 Green Composites with Excellent Barrier Properties 321
Arvind Gupta, Akhilesh Kumar Pal, Rahul Patwa, Prodyut Dhar and Vimal Katiyar

12.1 Introduction 321

12.2 Biodegradable Polymers: Classifications and Challenges 323

12.2.1 Poly (lactic acid): Properties Evaluation, Modifications and its Applications 328

12.2.2 Cellulose Based Composites: Chemical Modifications, Property Evaluation, and Applications. 333

12.2.3 Chitosan Based Composites: Chemical Modifications, Properties Evaluation, and Applications 338

12.2.4 Natural Gum Based Composites: Chemical Modification, Property Evaluation and Applications 343

12.2.5 Silk Based Composites: Property Evaluation, Chemical Modifications and Applications 348

12.3 Summary 355

Acknowledgements 355

References 356

13 Nanocellulose-Based Composites in Biomedical Applications 369
M. Osorio, A. Cañas, R. Zuluaga, P. Gañán, I. Ortiz and C. Castro

13.1 Introduction 370

13.2 Nanocellulose Sources and Properties 370

13.2.1 Nanocellulose Sources 370

13.2.2 Nanocellulose Characteristics as Green Material 373

13.2.3 Nanocellulose Properties for Biomedical Composites 374

13.2.3.1 Mechanical Properties 374

13.2.3.2 Morphology 375

13.2.3.3 Surface Charge 375

13.2.3.4 Conformability 378

13.2.3.5 Thermal Properties 378

13.2.3.6 Non-Toxic 379

13.2.3.7 Biocompatibility 379

13.3 Biomedical Applications of Nanocellulose-Based Composites 379

13.3.1 Nanocellulose-Based Composites with Various Polymers 380

13.3.1.1 Polyvinyl Alcohol 380

13.3.1.2 Chitosan (Ch) 381

13.3.1.3 Acrylic Acid (AA) 382

13.3.1.4 Polyhydroxyalkanoates (PHAs) 382

13.3.1.5 Silk Fibroin 383

13.3.1.6 Polyaniline and Polypyrrole 383

13.3.1.7 Alginate 384

13.3.1.8 Collagen 384

13.3.2 Nanocellulose-Based Composites with Bioactive Ceramics 385

13.3.2.1 Hydroxyapatite (HA) 385

13.3.2.2 Iron Oxide Nanoparticles 385

13.3.2.3 Calcium Peroxide (CaO₂) 386

13.3.2.4 Carbon Nanotubes 386

13.3.3 Nanocellulose-Based Composites with Metals 386

13.3.3.1 Silver Nanoparticles (Ag) 386

13.3.3.2 Gold Nanoparticles (Au) 387

13.4 Summary 387

13.5 Prospects 390

Acknowledgments 390

References 390

Index 403

Anil N. Netravali is the Jean and Douglas McLean Professor of Fiber Science and Apparel Design in the Department of Fiber Science and Apparel Design at Cornell University. Since 1984 he has been working in the field of polymer composites. He has published widely in the area of fiber/resin interface characterization and control through fiber surface modification and resin modification using nanoparticles and nanofibrils. In the past 25 years he has made significant contributions in the area of 'green' resins, composites and nanocomposites that are fully derived from plants. He was the recipient of the Fiber Society's Founders Award in 2012 and received the Green of the Crop award from the Creative Core (NY) in 2010.