Polymer Nanocomposites (eBook)

Aravind obtained the first degree (B. Tech in Chemical Engineering) from Jawaharlal Nehru Technological University, India in 1999 and M.S. (Chemical Engineering) from the University of Louisiana at Lafayette, USA in 2003. He then moved to University of Sydney, Australia where he obtained his PhD in 2007 from the Center for Advanced Materials Technology (CAMT). Upon completion of PhD, Dr Dasari continued to work as a post-doctoral fellow before moving to Madrid Institute of Advanced Studies of Materials (IMDEA Materials Institute) as a Research Scientist in early 2009 to lead the group on Multifunctional Nanocomposites. After a couple of years of exciting stint in Madrid, he joined NTU as an Assistant Professor in mid 2011. His research focuses on various aspects of hybrid polymer nanocomposites including combustion response, functional fabrics, food packaging and acoustic absorption in thin films.Zhong-Zhen Yu received his PhD in process engineering from the National Polytechnic Institute of Lorraine, France in 2001 and then worked as a postdoctoral and research fellow at the Centre for Advanced Materials Technology, The University of Sydney, for six years. From 1992 to 1999 he was a research fellow in the State Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences. He is now a professor of Polymer Engineering in the College of Materials Science and Engineering, Beijing University of Chemical Technology. His research interests cover many aspects of polymer blends, composites and nanocomposites, including toughening and strengthening with rigid particles and fibers, fracture behaviour, flame retardancy, conductivity, tribology and polymer processing.  Yiu-Wing Mai is an alumnus of the University of Hong Kong, having completed his BSc in 1969, his PhD in 1972 and his DSc in 1999. He also obtained a DEng from The University of Sydney in 1999. He previously worked in the US (Ann Arbor and NIST), the UK (Imperial College) and Hong Kong (HKUST and CityU). Professor Mai is currently University Chair and Professor of mechanical engineering at The University of Sydney. He is also Visiting Chair Professor of Mechanical and Aerospace Engineering at the Hong Kong Polytechnic University. Professor Mai's major research interests are the basic understanding of processing-microstructure-property relationships, particularly the fracture and mechanical behaviours of a range of advanced materials, including polymer blends, ceramics, cementitious materials, hard surface coatings and fibre composites. His current projects are related to polymer and ceramic-based nanocomposites and fracture mechanics of smart materials.

Foreword 6
Preface 8
Contents 10
1 Introduction: Toward Multi-functionality 14
References 16
2 Nanoparticles 18
2.1 Introduction 19
2.2 Different Types of Nanoparticles 25
2.2.1 Clay Minerals 25
2.2.2 Graphite Nanoplatelets 30
2.2.3 Carbon Nanotubes 33
2.2.4 Polyhedral Oligomeric Silsesquioxane 36
2.2.5 Other Equiaxed Nanoparticles 37
2.2.6 Hierarchical Structured Particles 38
References 42
3 Processing 47
3.1 Interfacial Volume and Its Effects 48
3.2 Modification of Nanoparticles 51
3.2.1 Equiaxed Nanoparticles 52
3.2.1.1 Surface Coating 53
3.2.1.2 Silanization 54
3.2.1.3 In Situ Particle Generation/Surface Modification 57
3.2.1.4 Coupling Agent 58
3.2.1.5 Grafting Treatment 58
3.2.2 Layered Silicates (Bentonite) 63
3.2.2.1 Opening of the Interlayer Spacing 63
3.2.2.2 Length of Alkyl Groups and Number of Tails 65
3.2.2.3 Difficulties with Nonpolar Polymers 65
3.2.3 Tubular Fillers (Carbon Nanotubes) 66
3.2.3.1 Adsorption 66
3.2.3.2 Chemical Functionalization 67
3.3 Processing of Polymer Nanocomposites 70
3.3.1 Solvent Methods 70
3.3.2 In Situ Polymerization 71
3.3.3 Polymer Melt Intercalation 73
References 74
4 Microstructural Characterization 80
4.1 Background 81
4.2 Direct and Reciprocal Space Techniques 82
4.3 Etching 85
4.4 Staining 88
4.5 Different Ways of Quantifying Dispersion/Distribution and Sizes of Nanoparticles 92
4.5.1 Equiaxed Nanoparticles 92
4.5.2 Clay Layers (1D Nanoparticles) 96
4.5.3 CNTs (2D Nanoparticles) 102
4.6 Other Advanced Techniques and Summary 107
References 109
5 Interfaces 113
5.1 Background 114
5.2 Crystallization Behavior 114
5.2.1 Crystallization Temperature 114
5.2.2 Crystal Size/Shape 117
5.2.3 Crystallization Under Nanoscopic Confinement 118
5.3 Spatial (Physical) Confinement in the Presence of Nanoparticles—Changes in Tg 121
5.4 Types of Hybrid Crystalline Structures 122
5.5 Concept of Transcrystallinity (TC) and Its Occurrence 125
5.6 TC in Polymer Nanocomposites 129
5.6.1 TC in the Presence of Layered Silicates 129
5.6.2 Extension of TC in Polymer Nanocomposites 132
5.6.3 Geometric Confinement Effect 133
References 137
6 Mechanical Properties 142
6.1 Background 143
6.2 Fracture Toughness and Ductility 145
6.3 Rigid Particle Toughening 146
6.4 Mobility Concept 155
6.5 Brittle Behavior of Polymer Nanocomposites 157
6.6 Influence of Transcrystallinity on Toughness/Ductility 158
6.7 Ternary Nanocomposites 161
6.8 Toughening by Inducing Voids 163
References 165
7 Thermal Properties 170
7.1 Background 171
7.2 Thermal Degradation of Polymers 173
7.3 Thermal Degradation of Polymer Nanocomposites 175
7.3.1 Clay-Based Polymer Nanocomposites 177
7.3.1.1 Catalytic Effect of Clay Layers 179
7.3.1.2 Effect of Low Molecular Weight Surfactants 180
7.3.2 Examples Illustrating the Effect of Nanoparticles on Thermal Stability of Polymers 184
7.4 Efforts to Improve Thermal Stability 187
References 190
8 Flame Retardancy 194
8.1 Background 195
8.2 Fundamentals of Combustion of Polymers 195
8.3 Conventional Flame Retardants 197
8.3.1 Halogen-Based FRs 197
8.3.2 Phosphorous-Based FRs 197
8.3.3 Metal Hydroxides 198
8.3.4 Intumescent Agents and Coatings 198
8.4 Ecological Impact of Conventional Flame Retardants 199
8.5 Flame Retardancy of Polymer Nanocomposites 200
8.5.1 Overall Behavior 200
8.5.2 TTI and Catalytic Activity of Smectite Clay 202
8.5.3 Testing Standards, Residue Quality, and Synergism with Conventional FRs 204
8.5.4 Understanding the Structure of Residues 206
8.5.4.1 XRD Analysis 206
8.5.4.2 Permeability 208
8.5.4.3 Electron Microscopy 210
8.6 Thickness of Samples 211
References 212
9 Wear/Scratch Damage 216
9.1 Background 216
9.2 Nanoparticles Versus Microsized Particles 219
9.3 Some Specific Parameters Affecting Wear/Scratch Damage in Polymer Nanocomposites 222
9.3.1 Transfer Films 222
9.3.2 Crystal Phase 223
9.4 General Comments on Wear/Scratch Damage of Polymer Nanocomposites 225
9.5 Hybrid Approach 227
9.6 Summary 231
References 231
10 Functional Properties 236
10.1 Optical Properties 237
10.2 Barrier Properties and Permeability 243
10.3 Electrical Conductivity 246
10.3.1 Percolation Threshold 247
10.3.2 Factors Affecting Percolation in Polymer Nanocomposites 248
10.3.3 Volume Exclusion Effect 253
10.4 Dielectric Properties 255
10.5 Biodegradability 259
10.5.1 Factors Affecting Biodegradation 261
10.5.2 Biodegradability of PLA-Based Nanocomposites 262
10.6 Summary 264
References 265
11 Ecological Issues 271
11.1 Background 272
11.2 Non-biodegradability of Polymeric Materials 272
11.3 Fire Retardants 274
11.3.1 Effects on Environment and Human Health 274
11.3.2 Source and Distribution 278
11.3.3 Efforts to Control/Monitor PBDEs 279
11.4 Food-Packaging Materials—Requirements and Concerns 280
References 283
12 Applications and Outlook 286
12.1 Background 287
12.2 Polymer/Clay Nanocomposites 288
12.2.1 Automotive Applications 288
12.2.2 Food Packaging and Other Barrier Property-Dependent Applications 289
12.2.3 Miscellaneous Applications 290
12.3 Nanocomposites for Marine Applications 291
12.4 Applications of Conductive Nanoparticles 293
12.5 Shape Memory Polymers 297
12.6 Biomedical Actuators and Other Biomechanical Applications 298
12.7 Summary and Outlook 301
References 302
Index 305