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Plastics Processing Technology
1 Characteristics of Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1 What Is a Polymer? ........................................................................ 1-1
1.2 Molecular Weight of Polymers . ............................................................ 1-3
1.2.1 Number-Average Molecular Weight ðM nÞ .......................................... 1-3
1.2.2 Weight-Average Molecular Weight ðM wÞ ........................................... 1-3
1.2.3 Viscosity-Average Molecular Weight ðM vÞ .......................................... 1-4
1.2.4 Polydispersity Index . . . ............................................................ 1-4
1.3 Polymerization Processes . . . ................................................................ 1-6
1.3.1 Addition or Chain Polymerization . . ............................................... 1-6
1.3.2 Coordination Addition Polymerization . . .......................................... 1-11
1.3.3 Step Polymerization . . . ........................................................... 1-14
1.3.4 Supramolecular Polymerization . .................................................. 1-18
1.3.5 Copolymerization . ............................................................... 1-22
1.4 Configurations of Polymer Molecules . . . .................................................. 1-24
1.5 Conformations of a Polymer Molecule . . .................................................. 1-25
1.6 Polymer Crystallinity . . . ................................................................... 1-26
1.6.1 Determinants of Polymer Crystallinity . . .......................................... 1-27
1.7 The Amorphous State . . ................................................................... 1-28
1.8 Structural Shape of Polymer Molecules . . .................................................. 1-29
1.9 Thermal Transitions in Polymers .......................................................... 1-31
1.9.1 Tg and Tm ........................................................................ 1-31
1.9.2 Regions of Viscoelastic Behavior .................................................. 1-34
1.9.3 Factors Affecting Tg ............................................................... 1-36
1.9.3.1 Chain Flexibility . . . ...................................................... 1-36
1.9.3.2 Steric Effects . . ........................................................... 1-37
1.9.3.3 Configurational Effects . .................................................. 1-37
1.9.3.4 Effect of Cross-Linking . .................................................. 1-38
1.9.4 Factors Affecting Tm .............................................................. 1-38
1.9.4.1 Symmetry . ............................................................... 1-38
1.9.4.2 Intermolecular Bonding .................................................. 1-39
1.9.4.3 Tacticity . . ............................................................... 1-40
1.9.4.4 Branching, Chain Flexibility, and Molecular Weight . ..................... 1-40
1.9.5 Relation between Tm and Tg ...................................................... 1-40
1.10 Designing a Polymer Structure for Improved Properties . .................................. 1-40
1.11 Cross-Linking of Polymer Chains . . . ...................................................... 1-42
1.11.1 Reactions of Functional Groups . .................................................. 1-42
1.11.2 Vulcanization . . ................................................................... 1-45
1.11.3 Radiation Cross-Linking .......................................................... 1-49
1.11.4 Photochemical Cross-Linking . . . .................................................. 1-51
1.11.5 Ionic Cross-Linking ............................................................... 1-52
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1.12 Solubility Behavior of Polymers ........................................................... 1-53
1.12.1 Solubility Parameter . . . ........................................................... 1-53
1.13 Effects of Corrosives on Polymers . . ....................................................... 1-60
1.14 Thermal Stability and Flame Retardation . . . ............................................... 1-63
1.14.1 Thermal Degradation . . ........................................................... 1-67
1.14.2 Ablation . . ........................................................................ 1-69
1.14.3 Flame Retardation ................................................................ 1-70
1.15 Deterioration of Polymers . ................................................................ 1-70
1.15.1 Chemical Deterioration ........................................................... 1-71
1.15.2 Degradation by Radiation . . ....................................................... 1-74
1.15.3 Microbiological Deterioration . . ................................................... 1-74
1.16 Stabilization of Polymers . . ................................................................ 1-75
1.16.1 Antioxidants and Related Compounds . ........................................... 1-76
1.16.2 Chemical Structures of Antioxidants . . . ........................................... 1-78
1.16.3 Stabilization of Selected Polymers . . ............................................... 1-80
1.16.3.1 Polypropylene . . ....................................................... 1-82
1.16.3.2 Polyethylene ........................................................... 1-82
1.16.3.3 Polystyrene . ........................................................... 1-83
1.16.3.4 Acrylonitrile–Butadiene–Styrene Copolymers .......................... 1-83
1.16.3.5 Polycarbonate . . ....................................................... 1-83
1.16.3.6 Nylons ................................................................ 1-83
1.16.3.7 Thermoplastic Elastomers . . ........................................... 1-84
1.16.3.8 Polyacetal . . ........................................................... 1-85
1.16.3.9 Poly(Vinyl Chloride) . . . ............................................... 1-85
1.16.3.10 Rubber ................................................................ 1-86
1.17 Metal Deactivators ........................................................................ 1-86
1.18 Light Stabilizers . . . ........................................................................ 1-88
1.18.1 Light Stabilizer Classes . ........................................................... 1-89
1.18.1.1 UV Absorbers ........................................................... 1-90
1.18.1.2 Quenchers . . . ........................................................... 1-91
1.18.1.3 Hydroperoxide Decomposers . ........................................... 1-92
1.18.1.4 Free-Radical Scavengers . . ............................................... 1-93
1.19 Light Stabilizers for Selected Plastics . . . ................................................... 1-96
1.19.1 Polypropylene .................................................................... 1-96
1.19.2 Polyethylene . . .................................................................... 1-96
1.19.3 Styrenic Polymers . ................................................................ 1-97
1.19.4 Poly(Vinyl Chloride) . . . ........................................................... 1-97
1.19.5 Polycarbonate . .................................................................... 1-98
1.19.6 Polyacrylates . . .................................................................... 1-98
1.19.7 Polyacetal . ........................................................................ 1-98
1.19.8 Polyurethanes . .................................................................... 1-98
1.19.9 Polyamides . . . .................................................................... 1-99
1.20 Diffusion and Permeability ................................................................ 1-99
1.20.1 Diffusion . ....................................................................... 1-100
1.20.2 Permeability . . ................................................................... 1-100
1.21 Polymer Compounding . . . ............................................................... 1-101
1.21.1 Fillers . ........................................................................... 1-103
1.22 Plasticizers ............................................................................... 1-104
1.22.1 Phthalic Acid Esters .............................................................. 1-108
1.22.2 Phosphoric Acid Esters . .......................................................... 1-108
1.22.3 Fatty Acid Esters . . ............................................................... 1-108
1.22.4 Polymeric Plasticizers . . .......................................................... 1-109
1.22.5 Miscellaneous Plasticizers . . ...................................................... 1-110
1.23 Antistatic Agents . . ....................................................................... 1-111
1.23.1 External Antistatic Agents . . ...................................................... 1-111
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1.23.2 Internal Antistatic Agents . . . ..................................................... 1-112
1.23.3 Chemical Composition of Antistatic Agents . ..................................... 1-112
1.23.3.1 Antistatic Agents Containing Nitrogen ................................. 1-113
1.23.3.2 Antistatic Agents Containing Phosphorus . . ............................ 1-114
1.23.3.3 Antistatic Agents Containing Sulfur . . . ................................. 1-115
1.23.3.4 Betaine-Type Antistatic Agents ......................................... 1-115
1.23.3.5 Nonionic Antistatic Agents ............................................. 1-115
1.24 Flame Retardants . . ...................................................................... 1-115
1.24.1 Halogen Compounds . . .......................................................... 1-116
1.24.2 Phosphorus Compounds ......................................................... 1-117
1.24.3 Halogen–Antimony Synergetic Mixtures . ......................................... 1-118
1.24.4 Intumescent Flame Retardants . . ................................................. 1-119
1.25 Smoke Suppressants . . . .................................................................. 1-119
1.26 Colorants . . .............................................................................. 1-119
1.27 Antimicrobials . .......................................................................... 1-120
1.28 Toxicity of Plastics . ...................................................................... 1-121
1.28.1 Plastic Devices in Pharmacy and Medicine . . ..................................... 1-121
1.28.1.1 Packing . . .............................................................. 1-122
1.28.1.2 Tubings and Blood Bag Assemblies ..................................... 1-122
1.28.1.3 Implants . .............................................................. 1-122
1.28.1.4 Adhesives .............................................................. 1-122
1.28.1.5 Dental Materials . . ..................................................... 1-122
1.28.1.6 Nanomedicines and Drug Delivery ..................................... 1-123
1.28.2 Biodegradable Plastics . . .......................................................... 1-124
1.28.3 Oxo-Biodegradable Plastics . ..................................................... 1-124
1.28.4 Toxicity of Plastic Combustion Products ......................................... 1-125
1.28.5 Toxicity Testing .................................................................. 1-125
References . . ................................................................................... 1-125
2 Fabrication Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1 Types of Processes . . ........................................................................ 2-1
2.2 Tooling for Plastics Processing . ............................................................ 2-1
2.2.1 Types of Mold . . .................................................................... 2-2
2.2.2 Types of Dies . . . .................................................................... 2-2
2.2.3 Tool Design . ........................................................................ 2-3
2.3 Compression Molding . .................................................................... 2-4
2.3.1 Open Flash . ........................................................................ 2-5
2.3.2 Fully Positive ........................................................................ 2-5
2.3.3 Semipositive ........................................................................ 2-5
2.3.4 Process Applicability ................................................................ 2-5
2.4 Transfer Molding . . ........................................................................ 2-6
2.4.1 Ejection of Molding . ................................................................ 2-8
2.4.2 Heating System . .................................................................... 2-8
2.4.3 Types of Presses . .................................................................... 2-9
2.4.4 Preheating . . ........................................................................ 2-9
2.4.5 Preforming . . ....................................................................... 2-10
2.4.6 Flash Removal . . ................................................................... 2-10
2.5 Injection Molding of Thermoplastics ...................................................... 2-10
2.5.1 Types of Injection Units .......................................................... 2-11
2.5.2 Clamping Units ................................................................... 2-13
2.5.3 Molds . ........................................................................... 2-13
2.5.3.1 Mold Designs ........................................................... 2-13
2.5.3.2 Number of Mold Cavities . .............................................. 2-14
2.5.3.3 Runners . ............................................................... 2-15
2.5.3.4 Gating . . . ............................................................... 2-15
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2.5.3.5 Venting . . ................................................................ 2-17
2.5.3.6 Parting Line . . . ........................................................... 2-17
2.5.3.7 Cooling . . ................................................................ 2-17
2.5.3.8 Ejection . . ................................................................ 2-17
2.5.3.9 Standard Mold Bases . . ................................................... 2-18
2.5.4 Structural Foam Injection Molding ............................................... 2-18
2.5.5 Co-Injection (Sandwich) Molding . ............................................... 2-18
2.5.6 Gas-Assisted Injection Molding ................................................... 2-20
2.6 Injection Molding of Thermosetting Resins . ............................................... 2-21
2.6.1 Screw-Injection Molding of Thermosetting Resins . . . .............................. 2-21
2.7 Extrusion . ................................................................................ 2-22
2.7.1 Extruder Capacity ................................................................ 2-23
2.7.2 Extruder Design and Operation ................................................... 2-24
2.7.2.1 Typical Screw Construction . . . ........................................... 2-24
2.7.2.2 Screw Zones . . ........................................................... 2-24
2.7.2.3 Motor Drive . . ........................................................... 2-25
2.7.2.4 Heating . . ................................................................ 2-25
2.7.2.5 Screw Design . . ........................................................... 2-25
2.7.3 Multiple-Screw Extruders . . ....................................................... 2-28
2.7.4 Blown-Film Extrusion . ........................................................... 2-28
2.7.5 Flat Film or Sheet Extrusion . . . ................................................... 2-29
2.7.6 Pipe or Tube Extrusion ........................................................... 2-32
2.7.7 Wire and Cable Coverings . ....................................................... 2-33
2.7.8 Extrusion Coating ................................................................ 2-33
2.7.9 Profile Extrusion . . ................................................................ 2-34
2.8 Blow Molding . ............................................................................ 2-34
2.8.1 Extrusion Blow Molding . . . ....................................................... 2-35
2.8.2 Injection Blow Molding ........................................................... 2-35
2.8.3 Blow Molds . . . .................................................................... 2-37
2.9 Calendering . . . ............................................................................ 2-37
2.10 Spinning of Fibers ........................................................................ 2-38
2.10.1 Melt Spinning .................................................................... 2-39
2.10.2 Dry Spinning . .................................................................... 2-40
2.10.3 Wet Spinning . .................................................................... 2-40
2.10.4 Cold Drawing of Fibers ........................................................... 2-42
2.11 Thermoforming . . . ........................................................................ 2-42
2.11.1 Vacuum Forming . ................................................................ 2-42
2.11.2 Pressure Forming . ................................................................ 2-42
2.11.3 Mechanical Forming . . . ........................................................... 2-43
2.12 Casting Processes . ........................................................................ 2-44
2.12.1 Simple Casting .................................................................... 2-44
2.12.2 Plastisol Casting . . ................................................................ 2-45
2.12.2.1 Dip Casting . . ........................................................... 2-46
2.12.2.2 Slush Casting ........................................................... 2-46
2.12.2.3 Rotational Casting . . . ................................................... 2-47
2.13 Reinforcing Processes . .................................................................... 2-47
2.13.1 Molding Methods . ................................................................ 2-47
2.13.1.1 Hand Lay-Up or Contact Molding ...................................... 2-48
2.13.1.2 Spray-Up ............................................................... 2-49
2.13.1.3 Matched Metal Molding . ............................................... 2-49
2.13.1.4 Vacuum-Bag Molding ................................................... 2-50
2.13.1.5 Pressure-Bag Molding ................................................... 2-50
2.13.1.6 Continuous Pultrusion . . . ............................................... 2-50
2.13.1.7 Filament Winding . . . ................................................... 2-50
2.13.1.8 Prepreg Molding . ....................................................... 2-52
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2.13.2 Fibrous Reinforcements ........................................................... 2-55
2.13.2.1 Glass Fibers . . ........................................................... 2-55
2.13.2.2 Graphite Carbon Fibers . . . .............................................. 2-56
2.13.2.3 Fiber Manufacture ...................................................... 2-57
2.13.2.4 Properties and Applications . . . .......................................... 2-59
2.13.2.5 Aramid Fibers .......................................................... 2-59
2.13.2.6 Applications . ........................................................... 2-60
2.13.2.7 Extended-Chain Polyethylene Fibers . . . .................................. 2-60
2.14 Reaction Injection Molding ............................................................... 2-62
2.14.1 Machinery . ....................................................................... 2-64
2.14.2 Polyurethanes . . ................................................................... 2-64
2.14.3 Nylons . ........................................................................... 2-65
2.15 Structural Reaction Injection Molding . . . .................................................. 2-65
2.15.1 Applications . . . ................................................................... 2-66
2.16 Resin Transfer Molding ................................................................... 2-66
2.17 Foaming Processes . ....................................................................... 2-67
2.17.1 Rigid Foam Blowing Agents . . . .................................................. 2-69
2.17.2 Polystyrene Foams ............................................................... 2-69
2.17.2.1 Extruded Polystyrene Foam . . .......................................... 2-70
2.17.2.2 Expandable Polystyrene . . .............................................. 2-70
2.17.2.3 Structural Foams ...................................................... 2-71
2.17.3 Polyolefin Foams . ............................................................... 2-72
2.17.4 Polyurethane Foams . . ........................................................... 2-76
2.17.4.1 Flexible Polyurethane Foams . .......................................... 2-76
2.17.4.2 Rigid and Semirigid Foams . . .......................................... 2-79
2.17.5 Foamed Rubber . . ............................................................... 2-80
2.17.6 Epoxy Resins . ................................................................... 2-80
2.17.7 Urea-Formaldehyde Foams ...................................................... 2-81
2.17.8 Silicone Foams . . . ............................................................... 2-82
2.17.9 Phenolic Foams . . ............................................................... 2-83
2.17.10 Poly(Vinyl Chloride) Foams . . . .................................................. 2-83
2.17.11 Special Foams ................................................................... 2-86
2.18 Rubber Compounding and Processing Technology . . ...................................... 2-88
2.18.1 Compounding Ingredients . . ...................................................... 2-88
2.18.1.1 Processing Aids . . . ...................................................... 2-94
2.18.1.2 Fillers ................................................................... 2-95
2.18.2 Mastication and Mixing ........................................................... 2-96
2.18.2.1 Open Mill . . . ........................................................... 2-96
2.18.2.2 Internal Batch Mixers . .................................................. 2-97
2.18.3 Reclaimed Rubber . ............................................................... 2-99
2.18.4 Some Major Rubber Products . . . ................................................. 2-100
2.18.4.1 Tires . .................................................................. 2-100
2.18.4.2 Belting and Hoses . ..................................................... 2-102
2.18.4.3 Cellular Rubber Products . ............................................. 2-104
2.19 Miscellaneous Processing Techniques ..................................................... 2-104
2.19.1 Coating Processes . . .............................................................. 2-104
2.19.1.1 Fluidized Bed Coating ................................................. 2-106
2.19.1.2 Spray Coating .......................................................... 2-106
2.19.1.3 Electrostatic Spraying . ................................................. 2-106
2.19.2 Powder Molding of Thermoplastics . ............................................. 2-107
2.19.2.1 Static (Sinter) Molding ................................................. 2-107
2.19.2.2 Rotational Molding . . . ................................................. 2-107
2.19.2.3 Centrifugal Casting . . . ................................................. 2-108
2.19.3 Adhesive Bonding of Plastics ..................................................... 2-108
2.19.3.1 Solvent Cementing ..................................................... 2-109
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2.19.3.2 Adhesive Bonding ...................................................... 2-110
2.19.3.3 Joining of Specific Plastics . . . .......................................... 2-110
2.19.4 Welding . . ....................................................................... 2-114
2.19.4.1 Hot-Gas Welding ...................................................... 2-114
2.19.4.2 Fusion Welding . . ...................................................... 2-114
2.19.4.3 Friction Welding . ...................................................... 2-115
2.19.4.4 High-Frequency Welding . .............................................. 2-115
2.19.4.5 Ultrasonic Welding . . .................................................. 2-115
2.20 Decoration of Plastics . ................................................................... 2-115
2.20.1 Painting . . ....................................................................... 2-116
2.20.2 Printing . . ....................................................................... 2-116
2.20.2.1 Gravure Printing . ...................................................... 2-116
2.20.2.2 Flexography . . .......................................................... 2-117
2.20.2.3 Screen Process Printing . . .............................................. 2-117
2.20.2.4 Pad Printing . .......................................................... 2-117
2.20.3 Hot Stamping . ................................................................... 2-117
2.20.4 In-Mold Decorating .............................................................. 2-118
2.20.5 Embossing ....................................................................... 2-118
2.20.6 Electroplating . ................................................................... 2-119
2.20.7 Vacuum Metallizing .............................................................. 2-119
References . . ................................................................................... 2-120
3 Plastics Properties and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1 Introduction . . ............................................................................. 3-1
3.2 Mechanical Properties . ..................................................................... 3-1
3.2.1 Stress and Strain . . ................................................................. 3-2
3.2.2 Stress–Strain Behavior . ............................................................ 3-4
3.2.3 Viscoelastic Behavior of Plastics .................................................... 3-7
3.2.3.1 Modulus and Compliance . ................................................ 3-8
3.2.4 Stress–Strain–Time Behavior . . . .................................................... 3-8
3.2.4.1 The WLF Equations . . . .................................................... 3-9
3.2.5 Creep Behavior . . . ................................................................ 3-11
3.2.6 Maxwell Model . . . ................................................................ 3-12
3.2.6.1 Stress–Strain Relation . ................................................... 3-13
3.2.6.2 Generalized Maxwell Model . . . ........................................... 3-15
3.2.7 Kelvin or Voigt Model . ........................................................... 3-17
3.2.7.1 Stress–Strain Relation . ................................................... 3-18
3.2.8 Four-Element Model . . . ........................................................... 3-19
3.2.9 Zener Model . . .................................................................... 3-20
3.2.10 Superposition Principle ........................................................... 3-21
3.2.11 Isometric and Isochronous Curves . ............................................... 3-22
3.2.12 Pseudoelastic Design Method . . ................................................... 3-23
3.2.13 Effect of Temperature . . ........................................................... 3-26
3.2.14 Time–Temperature Superposition . . ............................................... 3-26
3.2.15 Dynamic Mechanical Properties ................................................... 3-28
3.2.15.1 Maxwell Element ....................................................... 3-29
3.2.15.2 Terminology of Dynamic Mechanical Experiments ...................... 3-32
3.2.15.3 Dynamic Mechanical Behavior at Thermal Transitions . .................. 3-34
3.2.16 Rheological Behavior . . . ........................................................... 3-35
3.2.16.1 Classification of Fluid Behavior . . ....................................... 3-36
3.2.16.2 Effect of Shear Rate on Viscosity . ....................................... 3-39
3.2.16.3 Effect of Molecular Weight on Viscosity . . . .............................. 3-39
3.2.16.4 Effect of Temperature on Polymer Viscosity . . . .......................... 3-40
3.2.16.5 Effect of Pressure on Viscosity ........................................... 3-41
3.2.16.6 Weissenberg Effects . . ................................................... 3-41
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3.2.16.7 Irregular Flow or Melt Fracture . . . ...................................... 3-42
3.2.17 Measurement of Viscosity . . . ...................................................... 3-42
3.2.17.1 Rotational Viscometers.................................................. 3-43
3.2.17.2 Capillary Rheometers . .................................................. 3-44
3.2.18 Plastics Fractures . . . ............................................................... 3-46
3.2.19 Impact Behavior of Plastics . ...................................................... 3-46
3.2.20 Fatigue of Plastics . . ............................................................... 3-50
3.2.21 Hardness . . ....................................................................... 3-52
3.2.22 Indentation Hardness . . ........................................................... 3-52
3.2.22.1 Brinell Hardness Number . .............................................. 3-52
3.2.22.2 Vickers Hardness Number .............................................. 3-53
3.2.22.3 Knoop Hardness Number . .............................................. 3-53
3.2.22.4 Rockwell Hardness Number . . . .......................................... 3-53
3.2.22.5 Barcol Hardness . . ...................................................... 3-53
3.2.22.6 Durometer Hardness . . .................................................. 3-54
3.2.23 Rebound Hardness . ............................................................... 3-54
3.2.24 Scratch Hardness . . ............................................................... 3-55
3.2.25 Stress Corrosion Cracking of Polymers . . .......................................... 3-55
3.3 Reinforced Plastics . ....................................................................... 3-57
3.3.1 Types of Reinforcement ........................................................... 3-58
3.3.2 Types of Matrix ................................................................... 3-58
3.3.3 Analysis of Reinforced Plastics . . .................................................. 3-58
3.3.3.1 Continuous Fibers ...................................................... 3-59
3.3.3.2 Discontinuous Fibers . .................................................. 3-62
3.3.3.3 Fiber Length Less than Ic ................................................ 3-64
3.3.3.4 Fiber Length Equal to Ic ................................................ 3-65
3.3.3.5 Fiber Length Greater than Ic ............................................ 3-65
3.3.4 Deformation Behavior of Fiber-Reinforced Plastic ................................. 3-66
3.3.5 Fracture of Fiber-Reinforced Plastics .............................................. 3-66
3.3.5.1 Tension . . ............................................................... 3-67
3.3.5.2 Compression ........................................................... 3-67
3.3.5.3 Flexure or Shear . . ...................................................... 3-67
3.3.6 Fatigue Behavior of Reinforced Plastics . .......................................... 3-68
3.3.7 Impact Behavior of Reinforced Plastics . . .......................................... 3-68
3.4 Electrical Properties ....................................................................... 3-68
3.4.1 Dielectric Strength . ............................................................... 3-69
3.4.2 Insulation Resistance . . ........................................................... 3-70
3.4.3 Arc Resistance . ................................................................... 3-71
3.4.4 Dielectric Constant ............................................................... 3-72
3.4.4.1 Polarization and Dipole Moment . ...................................... 3-74
3.4.4.2 Dielectric Constant versus Frequency . .................................. 3-76
3.4.4.3 Dielectric Constant versus Temperature ................................. 3-76
3.4.4.4 Dielectric Losses . . ...................................................... 3-77
3.4.4.5 Dielectric Losses of Polar Polymers...................................... 3-78
3.5 Optical Properties . . ....................................................................... 3-78
3.5.1 Optical Clarity . ................................................................... 3-79
3.5.2 Index of Refraction ............................................................... 3-80
3.5.3 Piped Lighting Effect . . ........................................................... 3-81
3.5.4 Stress–Optical Characteristics . . . .................................................. 3-83
3.6 Thermal Properties . ....................................................................... 3-83
3.6.1 Specific Heat . . ................................................................... 3-83
3.6.2 Thermal Expansion ............................................................... 3-84
3.6.3 Thermal Conductivity . ........................................................... 3-86
3.6.4 Transition Temperatures and Temperature Limitations . . . ......................... 3-88
3.6.5 Standard Properties of Plastics . . .................................................. 3-90
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3.7 Identification of Common Plastics . ....................................................... 3-91
3.7.1 Behaviors on Heating and Ignition . . ............................................... 3-91
3.7.2 Tests for Characteristic Elements ................................................... 3-92
3.7.3 Specific Tests . . . .................................................................... 3-95
References . . ................................................................................... 3-102
4 Industrial Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.1 Introduction . . ............................................................................. 4-1
4.2 Part I: Addition Polymers . ................................................................. 4-2
4.2.1 Polyolefins . ......................................................................... 4-3
4.2.1.1 Polyethylene . . ............................................................ 4-3
4.2.1.2 Polypropylene . ............................................................ 4-9
4.2.1.3 Polyallomer . . . ........................................................... 4-15
4.2.1.4 Poly(Vinyl Chloride) . . ................................................... 4-16
4.2.1.5 Poly(Vinylidene Chloride) ............................................... 4-24
4.2.1.6 Polytetrafluoroethylene and Other Fluoropolymers . ...................... 4-25
4.2.1.7 Polyisobutylene . . . ....................................................... 4-29
4.2.1.8 Polystyrene . . . ........................................................... 4-30
4.2.1.9 Polybutadiene (Butadiene Rubber) ....................................... 4-31
4.2.1.10 Polyisoprene . . ........................................................... 4-31
4.2.1.11 Polychloroprene . . . ....................................................... 4-32
4.2.2 Olefin Copolymers . ................................................................ 4-32
4.2.2.1 Styrene–Butadiene Rubber . ............................................... 4-32
4.2.2.2 Nitrile Rubber . . ........................................................... 4-33
4.2.2.3 Ethylene–Propylene–Elastomer . ........................................... 4-33
4.2.2.4 Butyl Rubber . . . ........................................................... 4-35
4.2.2.5 Thermoplastic Elastomers . . ............................................... 4-35
4.2.2.6 Fluoroelastomers . . . ....................................................... 4-38
4.2.2.7 Styrene–Acrylonitrile Copolymer . . . ....................................... 4-39
4.2.2.8 Acrylonitrile–Butadiene–Styrene Terpolymer . .............................. 4-39
4.2.2.9 Ethylene–Methacrylic Acid Copolymers (Ionomers) . ...................... 4-42
4.2.3 Acrylics ............................................................................ 4-43
4.2.3.1 Polyacrylonitrile ........................................................... 4-43
4.2.3.2 Polyacrylates . . . ........................................................... 4-44
4.2.3.3 Polymethacrylates . . ....................................................... 4-45
4.2.3.4 Polyacrylamide . ........................................................... 4-47
4.2.3.5 Poly(Acrylic Acid) and Poly(Methacrylic Acid) . . .......................... 4-48
4.2.3.6 Acrylic Adhesives . . . ....................................................... 4-49
4.2.4 Vinyl Polymers . .................................................................... 4-50
4.2.4.1 Poly(Vinyl Acetate) . ....................................................... 4-50
4.2.4.2 Poly(Vinyl Alcohol) ....................................................... 4-52
4.2.4.3 Poly(Vinyl Acetals) . ....................................................... 4-53
4.2.4.4 Poly(Vinyl Cinnamate) . ................................................... 4-53
4.2.4.5 Poly(Vinyl Ethers) . . ....................................................... 4-54
4.2.4.6 Poly(Vinyl Pyrrolidone) ................................................... 4-54
4.2.4.7 Poly(Vinyl Carbazole) . . ................................................... 4-54
4.3 Part II: Condensation Polymers ........................................................... 4-55
4.3.1 Polyesters . . ........................................................................ 4-55
4.3.1.1 Poly(Ethylene Terephthalate) . . . ........................................... 4-55
4.3.1.2 Poly(Butylene Terephthalate) . . . ........................................... 4-57
4.3.1.3 Poly(Dihydroxymethylcyclohexyl Terephthalate) . .......................... 4-58
4.3.1.4 Unsaturated Polyesters . ................................................... 4-59
4.3.1.5 Aromatic Polyesters ....................................................... 4-66
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4.3.1.6 Wholly Aromatic Copolyester . . . .......................................... 4-68
4.3.1.7 Polycarbonates ........................................................... 4-69
4.3.2 Polyamides . . ....................................................................... 4-71
4.3.2.1 Aliphatic Polyamides . . .................................................. 4-72
4.3.2.2 Aromatic Polyamides . . .................................................. 4-80
4.3.2.3 Polyimides ............................................................... 4-82
4.3.3 Formaldehyde Resins ............................................................... 4-87
4.3.3.1 Phenol–Formaldehyde Resins . . .......................................... 4-88
4.3.3.2 Urea–Formaldehyde Resins . .............................................. 4-92
4.3.3.3 Melamine–Formaldehyde Resins . . . ...................................... 4-96
4.3.4 Polyurethanes . . . ................................................................... 4-97
4.3.4.1 Polyurethane Rubbers and Spandex Fibers . . ............................. 4-99
4.3.4.2 Flexible Polyurethane Foam ............................................. 4-103
4.3.4.3 Rigid and Semirigid Polyurethane Foams ................................ 4-104
4.3.4.4 Polyurethane Coatings . ................................................. 4-105
4.3.5 Ether Polymers . . .................................................................. 4-106
4.3.5.1 Polyacetal . .............................................................. 4-107
4.3.5.2 Poly(Ethylene Oxide) . . ................................................. 4-109
4.3.5.3 Applications . . .......................................................... 4-110
4.3.5.4 Poly(Propylene Oxide) . ................................................. 4-112
4.3.5.5 Epoxy Resins . .......................................................... 4-114
4.3.5.6 Poly(Phenylene Oxide) . ................................................. 4-126
4.3.6 Cellulosic Polymers . .............................................................. 4-128
4.3.6.1 Regenerated Cellulose . . ................................................. 4-128
4.3.6.2 Cellulose Nitrate . . . ..................................................... 4-129
4.3.6.3 Cellulose Acetate . . . ..................................................... 4-130
4.3.6.4 Other Cellulose Esters . ................................................. 4-131
4.3.6.5 Cellulose Ethers ......................................................... 4-131
4.3.7 Sulphide Polymers . . .............................................................. 4-132
4.3.7.1 Polysulfides . . . .......................................................... 4-132
4.3.7.2 Poly(Phenylene Sulfide) ................................................. 4-133
4.3.8 Polysulfone . ...................................................................... 4-134
4.3.8.1 Properties .............................................................. 4-135
4.3.9 Polether Ether Ketone . . . .......................................................... 4-136
4.3.10 Polybenzimidazole . . .............................................................. 4-138
4.3.11 Silicones and Other Inorganic Polymers . . ......................................... 4-139
4.3.11.1 Silicones . . .............................................................. 4-139
4.3.11.2 Polyphosphazenes . . ..................................................... 4-145
4.3.11.3 Polythiazyl .............................................................. 4-146
4.3.12 Polyblends . . ...................................................................... 4-146
4.3.12.1 Prediction of Polyblend Properties . ..................................... 4-150
4.3.12.2 Selection of Blend Components ......................................... 4-151
4.3.12.3 Compatibilization of Polymers . ......................................... 4-152
4.3.12.4 Industrial Polyblends . . . ................................................. 4-154
4.3.12.5 Nanoblends . . . .......................................................... 4-156
4.3.13 Interpenetrating Polymer Networks . . ............................................. 4-157
4.3.13.1 Industrial IPNs ......................................................... 4-159
References . . ................................................................................... 4-159
5 Polymers in Special Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1 Introduction . . . ............................................................................ 5-1
5.2 High-Temperature and Fire-Resistant Polymers . . ........................................... 5-1
5.2.1 Temperature-Resistant Polymers ................................................... 5-2
5.2.2 Fire-Resistant Polymers ............................................................ 5-4
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5.3 Liquid Crystal Polymers . . ................................................................. 5-5
5.3.1 Thermotropic Main-Chain Liquid Crystal Polymers . .............................. 5-11
5.3.2 Side-Chain Liquid Crystal Polymers............................................... 5-13
5.3.3 Chiral Nematic Liquid Crystal Polymers . . . ....................................... 5-14
5.3.4 Properties of Commercial LCPs ................................................... 5-17
5.3.5 Applications . . .................................................................... 5-19
5.4 Electroactive Polymers .................................................................... 5-19
5.4.1 Filled Polymers . . . ................................................................ 5-19
5.4.1.1 EMI Shielding . ........................................................... 5-22
5.4.1.2 Conductive Coating . . . ................................................... 5-24
5.4.1.3 Signature Materials ....................................................... 5-25
5.4.2 Inherently Conductive Polymers . . . ............................................... 5-26
5.4.2.1 Doping . . ................................................................ 5-28
5.4.2.2 Conducting Mechanisms . . ............................................... 5-33
5.4.2.3 Applications . . ........................................................... 5-35
5.4.3 Photoconductive Polymers . ....................................................... 5-43
5.4.4 Polymers in Fiber Optics . . . ....................................................... 5-44
5.4.5 Polymers in Nonlinear Optics . . ................................................... 5-47
5.4.6 Langmuir–Blodgett Films . . ....................................................... 5-48
5.4.7 Piezo-and Pyroelectric Polymers . . . ............................................... 5-49
5.4.7.1 Applications . . ........................................................... 5-51
5.4.8 Polymeric Electrolytes . . . ........................................................... 5-53
5.5 Polymers in Photoresist Applications . . . ................................................... 5-55
5.5.1 Negative Photoresists . . ........................................................... 5-58
5.5.2 Positive Photoresists . . . ........................................................... 5-61
5.5.2.1 Near-UV Application . . ................................................... 5-61
5.5.2.2 Mid-and Deep-UV Photoresists . . . ....................................... 5-63
5.5.3 Electron Beam Resists . . ........................................................... 5-66
5.5.4 Plasma-Developable Photoresists . . . ............................................... 5-67
5.6 Photoresist Applications for Printing . . . ................................................... 5-68
5.6.1 Printing Plates .................................................................... 5-68
5.6.1.1 Relief or Raised-Image Plates . . ........................................... 5-68
5.6.1.2 Photolithography/Planographic Plates . . .................................. 5-70
5.6.1.3 Photogravure . ........................................................... 5-70
5.6.2 Photoengraving . . . ................................................................ 5-70
5.6.3 Printed Circuits . . . ................................................................ 5-71
5.6.4 Collotype and Proofing Systems . . . ............................................... 5-71
5.7 Optical Information Storage . . . ........................................................... 5-71
5.8 Polymers in Adhesives .................................................................... 5-72
5.8.1 Solvent-Based Adhesives . . . ....................................................... 5-73
5.8.2 Water-Based Adhesives . ........................................................... 5-75
5.8.3 Hot Melt Adhesives ............................................................... 5-76
5.8.4 Radiation-Curable Adhesives . . . ................................................... 5-76
5.9 Degradable Polymers . . .................................................................... 5-77
5.9.1 Packaging Application . ........................................................... 5-79
5.9.2 Medical and Related Applications . . ............................................... 5-80
5.9.2.1 Synthetic Polymers ....................................................... 5-80
5.9.2.2 Controlled Release Agents . ............................................... 5-81
5.9.2.3 Tissue Engineering ....................................................... 5-82
5.10 Ionic Polymers ............................................................................ 5-84
5.10.1 Physical Properties and Applications . . . ........................................... 5-86
5.10.1.1 Ionic Cross-Linking . . ................................................... 5-86
5.10.1.2 Ion-Exchange ........................................................... 5-86
5.10.1.3 Hydrophilicity . . . ....................................................... 5-88
5.10.2 Ionomers . ........................................................................ 5-91
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5.10.2.1 Polyethylene Ionomers .................................................. 5-91
5.10.2.2 Elastomeric Ionomers . .................................................. 5-93
5.10.2.3 Ionomers Based on Polytetrafluoroethylene ............................. 5-94
5.10.2.4 Ionomers Based on Polysulfones . . ...................................... 5-96
5.10.3 Polyelectrolytes ................................................................... 5-97
5.10.3.1 Ion-Exchangers . . . ...................................................... 5-97
5.10.3.2 Applications . .......................................................... 5-102
5.10.3.3 Polycarboxylates . . ..................................................... 5-105
5.10.3.4 Integral Polyelectrolytes . . . ............................................. 5-105
5.11 Scavenger Resins . . . ...................................................................... 5-106
5.12 Synthetic Polymer Membranes . .......................................................... 5-107
5.12.1 Membrane Preparation .......................................................... 5-107
5.12.1.1 Wet-Extrusion Process ................................................. 5-107
5.12.1.2 Hollow-Fiber Membranes . ............................................. 5-110
5.12.2 Membrane Modules .............................................................. 5-111
5.12.3 Applications . . . .................................................................. 5-113
5.13 Hydrogels and Smart Polymers .......................................................... 5-115
5.13.1 Smart Polymers .................................................................. 5-117
5.14 Dendritic Polymers ...................................................................... 5-123
5.14.1 Applications . . . .................................................................. 5-124
5.15 Shape Memory Polymers . . . .............................................................. 5-126
5.16 Microencapsulation ...................................................................... 5-128
5.16.1 Processes for Microencapsulation . . . ............................................. 5-129
5.16.1.1 Complex Coacervation ................................................. 5-129
5.16.1.2 Polymer-Polymer Incompatibility . ..................................... 5-130
5.16.1.3 Interfacial and in Situ Polymerization . ................................. 5-130
5.16.1.4 Spray Drying .......................................................... 5-133
5.16.1.5 Fluidized-Bed Coating ................................................. 5-134
5.16.1.6 Co-Extrusion Capsule Formation . ..................................... 5-135
5.16.1.7 Other Processes . . . ..................................................... 5-136
5.16.2 Applications . . . .................................................................. 5-137
5.17 Polymer Nanocomposites . . .............................................................. 5-138
5.17.1 Preparation of Polymer Nanocomposites ......................................... 5-139
5.17.2 Applications of Polymer Nanocomposites . . . ..................................... 5-144
5.18 Wood–Polymer Composites .............................................................. 5-146
5.18.1 WPC Feedstocks . . . .............................................................. 5-147
5.18.1.1 Wood .................................................................. 5-147
5.18.1.2 Plastics . . .............................................................. 5-148
5.18.1.3 Compounded Pellets . . ................................................. 5-148
5.18.1.4 Additives .............................................................. 5-148
5.18.2 Manufacture of WPC Products . . ................................................. 5-148
5.18.2.1 Compounding ......................................................... 5-149
5.18.2.2 Extrusion .............................................................. 5-149
5.18.3 Properties of WPC Products ..................................................... 5-151
5.18.4 Applications of WPC Products . . ................................................. 5-152
5.19 Polymerization-Filled Composites . . . ..................................................... 5-154
References . . . ................................................................................... 5-155
6 Recycling of Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.1 Introduction . . . ............................................................................ 6-1
6.2 Outline of Recycling Methods . . ............................................................ 6-2
6.3 Recycling of Poly (Ethylene Terephthalate) . . ............................................... 6-8
6.3.1 Direct Reuse . . . .................................................................... 6-8
6.3.2 Reuse after Modification ........................................................... 6-9
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6.3.2.1 Glycolysis ................................................................ 6-10
6.3.2.2 Methanolysis . . ........................................................... 6-12
6.3.2.3 Ammonolysis . ........................................................... 6-12
6.3.2.4 Hydrolysis ............................................................... 6-12
6.3.2.5 Depolymerization in Supercritical Fluids . . . .............................. 6-13
6.3.2.6 Enzymatic Depolymerization . . ........................................... 6-13
6.3.3 Incineration . . .................................................................... 6-14
6.4 Recycling of Polyurethanes ................................................................ 6-15
6.4.1 Thermopressing Process . . . ....................................................... 6-15
6.4.2 Kneader Process . . ................................................................ 6-16
6.4.3 Hydrolysis ........................................................................ 6-17
6.4.3.1 Glycolysis ................................................................ 6-17
6.4.3.2 Ammonolysis . ........................................................... 6-17
6.5 Recycling of Poly (Vinyl Chloride) . ....................................................... 6-19
6.5.1 Characterization of Used PVC . ................................................... 6-19
6.5.2 In-Line PVC Scrap ................................................................ 6-20
6.5.3 PVC Floor Coverings . . ........................................................... 6-22
6.5.4 PVC Roofing Sheets . . . ........................................................... 6-22
6.5.5 Post-Consumer PVC . . . ........................................................... 6-22
6.6 Recycling of Cured Epoxies ............................................................... 6-23
6.7 Recycling of Mixed Plastics Waste . . ....................................................... 6-23
6.7.1 Direct Reuse . . .................................................................... 6-24
6.7.2 Homogeneous Fractions . . . ....................................................... 6-27
6.7.3 Liquefaction of Mixed Plastics . ................................................... 6-27
6.8 Post-Consumer Polyethylene Films . ....................................................... 6-28
6.9 Recycling of Ground Rubber Tires . ....................................................... 6-29
6.10 Recycling of Car Batteries . ................................................................ 6-31
6.11 Plastic Recycling Equipment and Machinery ............................................... 6-31
6.11.1 Plastocompactor . . ................................................................ 6-32
6.11.2 Debaling and Initial Size Reduction ............................................... 6-32
6.11.2.1 Shredder ................................................................ 6-33
6.11.2.2 Cutter or Guillotine . . ................................................... 6-33
6.11.2.3 Screw Shredder . . ....................................................... 6-33
6.11.2.4 Granulators . . ........................................................... 6-33
6.11.2.5 Fine Grinding ........................................................... 6-34
6.11.3 Cleaning and Selection . ........................................................... 6-34
6.11.3.1 Dry Separation . . ....................................................... 6-35
6.11.3.2 Wet Separation . . ....................................................... 6-36
6.11.3.3 Other Methods . . ....................................................... 6-37
6.11.4 Resin Detectors: Type and Configuration . . . ....................................... 6-37
6.11.5 Automatic Sortation . . . ........................................................... 6-39
6.11.5.1 PVC/PET and Commingled Plastics Sortation . .......................... 6-39
6.11.6 Recycle Installations ............................................................... 6-41
References . . . .................................................................................... 6-41
7 Trends in Polymer Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.1 Introduction . . ............................................................................. 7-1
7.2 Polymers in Packaging ..................................................................... 7-2
7.2.1 Retorting . ......................................................................... 7-4
7.2.2 Asceptic Packaging ................................................................. 7-4
7.2.3 Hot-Filling . . . ..................................................................... 7-5
7.2.4 Controlled-Atmosphere Packaging . ................................................ 7-5
7.2.5 High-Barrier Films ................................................................ 7-5
7.2.6 Oxygen Scavenger-Based Packaging ................................................ 7-6
7.2.7 Plastic Bottles . ..................................................................... 7-6
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7.2.8 Chemical Containers . . ............................................................ 7-7
7.2.9 Dual Ovenables .................................................................... 7-7
7.2.10 Closures . . . ........................................................................ 7-8
7.2.11 Biodegradable Packaging ........................................................... 7-8
7.2.12 Pharmaceutics Packaging and Nanomedicines . . . ................................... 7-9
7.2.13 Wood–Plastic Composites . . . ...................................................... 7-10
7.3 Polymers in Building and Construction . .................................................. 7-10
7.3.1 Roofing ........................................................................... 7-11
7.3.2 Flooring . . . ....................................................................... 7-11
7.3.3 Windows . . ....................................................................... 7-12
7.3.4 Pipes . . ........................................................................... 7-13
7.3.5 Insulation . ....................................................................... 7-13
7.3.6 Polymer–Concrete Composites . . .................................................. 7-14
7.3.7 Wood–Plastic Composites . . ...................................................... 7-16
7.4 Polymers in Corrosion Prevention and Control . . .......................................... 7-16
7.4.1 Flue Gas Desulfurization .......................................................... 7-17
7.4.2 Chemical Resistant Masonry ...................................................... 7-17
7.4.3 Piping Systems ................................................................... 7-18
7.4.4 Boiler and Cooling Water Treatment .............................................. 7-18
7.4.5 Biodegradable Scale Inhibitor . . . .................................................. 7-18
7.4.6 Reinforcing Steel in Concrete . . . .................................................. 7-19
7.5 Plastics in Automotive Applications . ...................................................... 7-20
7.5.1 Exterior Body Parts ............................................................... 7-20
7.5.2 Interior Components . . ........................................................... 7-21
7.5.3 Load-Bearing Parts ............................................................... 7-22
7.5.4 Under-the-Bonnet (Hood) . . ...................................................... 7-22
7.5.5 Future Trends . ................................................................... 7-23
7.5.6 Polymer Nanocomposites . . . ...................................................... 7-23
7.5.7 “Green” Composites . . ........................................................... 7-24
7.6 Polymers in Aerospace Applications . ...................................................... 7-25
7.6.1 Carbon Fibers . ................................................................... 7-25
7.6.2 Resins . ........................................................................... 7-26
7.7 Polymers in Electrical and Electronic Applications . . . ...................................... 7-27
7.7.1 Wire and Cable Insulation . . ...................................................... 7-28
7.7.2 Polymer Insulators . ............................................................... 7-29
7.7.3 Printed Circuit Boards . ........................................................... 7-29
7.7.4 Connectors ....................................................................... 7-29
7.7.5 Enclosures . ....................................................................... 7-30
7.7.6 Optical Fibers . ................................................................... 7-30
7.7.7 Information Storage Discs . . ...................................................... 7-31
7.7.8 Polymeric FET and LED .......................................................... 7-32
7.8 Polymers in Agriculture and Horticulture . . . .............................................. 7-33
7.8.1 Plastic Film ....................................................................... 7-33
7.8.2 Plastic Crates . . ................................................................... 7-34
7.8.3 Building . . . ....................................................................... 7-34
7.8.4 Pipes and Hoses . . . ............................................................... 7-34
7.8.5 Greenhouses . . . ................................................................... 7-35
7.9 Polymers in Domestic Appliances and Business Machines ................................. 7-35
7.9.1 Large Appliances . . . ............................................................... 7-36
7.9.2 Small Appliances . . ............................................................... 7-37
7.9.3 Business Equipment . . . ........................................................... 7-37
7.9.4 Air Filters . ....................................................................... 7-38
7.9.5 Solar Systems . . ................................................................... 7-38
7.10 Polymers in Medical and Biomedical Applications . . . ...................................... 7-39
7.10.1 Medical Packaging . ............................................................... 7-39
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7.10.2 Nontoxic Sterilizable Items . ....................................................... 7-40
7.10.3 Biodegradable Polymers ........................................................... 7-41
7.10.4 Conducting Polymer Nanotubes . . . ............................................... 7-41
7.10.5 Biomimetic Actuators . . ........................................................... 7-42
7.10.6 Dental Resin Composites . . ....................................................... 7-43
7.10.7 Appliances ........................................................................ 7-43
7.10.8 Disposables . . . .................................................................... 7-43
7.11 Polymers in Marine and Offshore Applications . ........................................... 7-44
7.11.1 Cables ............................................................................ 7-44
7.11.2 Coatings . . ........................................................................ 7-44
7.11.3 Other Applications ................................................................ 7-45
7.12 Polymers in Sport . ........................................................................ 7-45
7.12.1 Synthetic Surfaces . ................................................................ 7-45
7.12.2 Footwear . ........................................................................ 7-46
7.12.3 Equipment ........................................................................ 7-46
References . . . .................................................................................... 7-47