R. N. Kumar - Adhesives for Wood and Lignocellulosic Materials

1 Cover

2 Preface References

3 Part A: Substrates, Adhesives, and Adhesion Chapter 1: Wood as a Unique Adherend 1.1 Introduction 1.2 Wood, An Adherend with Hierarchical Structure 1.3 Details of Structural Hierarchy in Wood 1.4 Chemical Composition 1.5 Influence of Hierarchical Structure of Wood on Wood–Adhesive Interaction 1.6 Effect of Hierarchical Structure of Wood on Adhesive Penetration 1.7 Wood Factors Affecting Penetration 1.8 Influence of Resin Type and Formulation on Penetration 1.9 Effect of Processing Parameters on Penetration References Chapter 2: Fundamentals of Adhesion 2.1 Introduction 2.2 Definitions 2.3 Mechanism of Adhesion 2.4 Theories of Adhesion 2.5 Electronic Theory 2.6 Diffusion Theory 2.7 Adsorption/Covalent Bond Theory 2.8 Adhesion Interactions as a Function of Length Scale 2.9 Wetting of the Substrate by the Adhesive 2.10 Equilibrium Contact Angle 2.11 Thermodynamic Work of Adhesion 2.12 Spreading Coefficient 2.13 Zisman’s Rectilinear Relationship—Zisman’s Plots and Critical Surface Tension of a Solid 2.14 Effect of Surface Roughness on Contact Angle 2.15 Weak Boundary Layer Theory 2.16 Measurement of the Wetting Parameters for Wood Substrate 2.17 Covalent Bond Formation References Chapter 3: Urea–Formaldehyde Resins 3.1 Introduction 3.2 Historical Review of UF Resins (Plastic Historical Society) [3] 3.3 Reaction between Urea and Formaldehyde 3.4 Reaction Sequence 3.5 Manufacture of UF Resin 3.6 Chemistry of Reaction—Conventional Process (Alkaline–Acid Process/Three-Step Process) 3.7 Composition of the Commercial UF Resins 3.8 Reactions of UF during Storage 3.9 Reaction Parameters in the Production of Amino Resins (General) 3.10 Four-Step Process for Low Formaldehyde Emission 3.11 Curing of UF Resins 3.12 Cross-Linked Structure 3.13 Triazinone for Curing the UF Resin 3.14 Distinguishing Feature of UF from other Synthetic Resin Adhesives such as MUF and PF 3.15 Other Curing Agents 3.16 Protic Ionic Liquids as a New Hardener-Modifier System 3.17 Improvement of Water Resistance and Adhesive Performance of UF Resin [71] 3.18 Characterization of UF Resin 3.19 UF Resin Cure Kinetics 3.20 UF Resins with Low Formaldehyde Emission 3.21 Modification by Polyamines 3.22 Cyclic Urea Prepolymer 3.23 Improvement of UF and MUF Resins by Addition of Hyperbranched Dendrimers References Chapter 4: Melamine–Formaldehyde Resin 4.1 Introduction 4.2 Chemistry 4.3 Melamine–Urea–Formaldehyde (MUF) Resin References Chapter 5: Phenol–Formaldehyde Resins 5.1 Introduction 5.2 Historical 5.3 Definitions and Types of Phenolic Resins 5.4 Basic Chemistry 5.5 Effect of Process Variables 5.6 Commercial Phenolic Resin for Wood Products 5.7 Curing of Phenolic Resin References Chapter 6: Resorcinol–Formaldehyde Resins and Hydroxymethyl Resorcinol (HMR and n-HMR) 6.1 Introduction 6.2 Reaction between Resorcinol and Formaldehyde 6.3 Comparison between Resorcinol and Phenol 6.4 Reactive Positions and Types of Linkages Comparison between Resorcinol and Phenol 6.5 Hydroxymethyl Resorcinol 6.6 Novolak-Based HMR 6.7 Bonding Mechanism Using HMR 6.8 Applications of HMR and n-HMR 6.9 Special Adhesives of Reduced Resorcinol Content References Chapter 7: Polyurethane Adhesives 7.1 Introduction 7.2 History 7.3 Reactions of Isocyanates 7.4 Raw Materials 7.5 Catalysts 7.6 Blocked Isocyanates 7.7 Advantages of pMDI 7.8 PU Adhesive–Wood Interaction 7.9 PU–UF Hybrid Adhesives 7.10 PU–PF Hybrid Adhesives 7.11 EMDI-Based Adhesives 7.12 Emulsion Polymer Isocyanate (EPI) Adhesive 7.13 Non-Isocyanate Polyurethanes and Biobased PU Adhesives References Chapter 8: Wood Surface Inactivation (Thermal) 8.1 Introduction 8.2 Causes and Sources of Inactivation 8.3 Mechanisms of Inactivation 8.4 Factors Affecting Wood Surface Inactivation 8.5 Physical Mechanisms of Inactivation 8.6 Chemical Mechanisms of Inactivation References Chapter 9: Wood Surface Inactivation Due to Extractives 9.1 Introduction 9.2 Migration of Extractives to the Wood Surface 9.3 Influence of Extractives on Bonding Properties of Wood 9.4 Effect of pH of Wood on the Adhesion 9.5 Effect of Extractive Migrations during Kiln Seasoning on Adhesion 9.6 Methods to Reduce the Influence of Extractives on Wood Adhesion References Chapter 10: Surface Modification of Wood 10.1 Introduction 10.2 Surface Modification Methods 10.3 Enzymatic Modification for Hydrophobicity 10.4 Modification of Wood Surface by Chemical Treatment—Functionalization of Wood 10.5 Sol–Gel Method References Chapter 11: The Chemistry of Condensed Tannins 11.1 Introduction 11.2 Reactions of Condensed Flavonoid Tannins 11.3 Conclusions References Chapter 12: Thermosetting Adhesives Based on Bio-Resources for Lignocellulosic Composites 12.1 Introduction 12.2 Tannin Adhesives 12.3 Lignin Adhesives 12.4 Protein Adhesives 12.5 Carbohydrate Adhesives 12.6 Unsaturated Oil Adhesives 12.7 Wood Welding without Adhesives 12.8 Conclusions References Chapter 13: Environmental Aspects of Adhesives—Emission of Formaldehyde 13.1 Introduction 13.2 Scientific Analysis of the Problem 13.3 Factors Affecting the Amount of Formaldehyde Emission 13.4 Exposure 13.5 Safe Level of Formaldehyde Exposure 13.6 Evolution of Formaldehyde Emission Standards 13.7 CARB Green Adhesive Formaldehyde Emission Standards 13.8 Japanese JIS/JAS Formaldehyde Adhesive Emission Standards [21–23] 13.9 European Formaldehyde Emission Standards [24–33] 13.10 Standardization and Test Methods 13.11 Different Standards and Test Methods References Chapter 14: Rheology and Viscoelasticity of Adhesives 14.1 Rheology of Adhesives 14.2 Viscosity—Theory 14.3 Capillary Viscometry 14.4 Rotational Viscometers 14.5 Cone-and-Plate Viscometer 14.6 Parallel Plate Viscometer 14.7 Concentric Cylinder Viscometer 14.8 Ford Cup Viscosity 14.9 Gardner–Holt Tubes 14.10 Newtonian and Non-Newtonian Fluids 14.11 Viscoelasticity of Adhesives 14.12 Dynamic Mechanical Analysis 14.13 TTT and CHT Diagrams 14.14 Experimental Results References Chapter 15: Hot Melt Adhesives 15.1 Introduction 15.2 Polymers Commonly Used for Hot Melt Adhesives 15.3 Polyureathane Reactive Hot Melt Adhesives 15.4 Silane Reactive Hot Melt Adhesives 15.5 Polyamide Hot Melt Adhesives 15.6 Amorphous Polyolefin (APO/APAO) Hot Melt Adhesives 15.7 Tackifiers 15.8 Antioxidants [22] 15.9 Plasticizers 15.10 Mineral Oil and Wax References

4 Part B: Polymer Matrix Materials for Biofiber Composites Chapter 16: Modification of Natural Fibers and Polymeric Matrices 16.1 Introduction 16.2 Strategies to Treat the Biofibers for Compatibility 16.3 Chemical Methods 16.4 Functionalization of Matrices for Compatibility 16.5 MAH Grafted Polyolefins as Matrix Additives 16.6 Reactive Extrusion System References Chapter 17: Polymer Matrix: Unsaturated Polyester 17.1 Introduction 17.2 Raw Materials 17.3 Polyesterification Reaction 17.4 Cross-Linking Reaction 17.5 Sheet Molding Compounds Based on UP Resins 17.6 UV Curable Compositions Based on UP/Vinyl Ester Resins 17.7 Biocomposites Based on UP Matrix References Chapter 18: Polymer Matrix: Epoxy Resins 18.1 Introduction 18.2 Resin Preparation 18.3 Characteristics of Epoxy Resins 18.4 Preparation of DGEBA Epoxy Resin 18.5 Other Types of Epoxy Resins 18.6 Green or Sustainable Epoxy Matrix 18.7 Epoxy-Matrix-Based Biofiber Composites References Chapter 19: Polymer Matrix: Polyethylene 19.1 Introduction 19.2 High-Pressure Process 19.3 Low-Pressure Processes—Catalysts for Polymerization 19.4 Production of PE 19.5 Compatibilizers 19.6 Relevant Property of PE 19.7 Treatment and Functionalizing of Biofibers and Matrix Materials 19.8 Biocomposites Based on PE References Chapter 20: Polymer Matrix: Polypropylene 20.1 Introduction 20.2 PP Manufacture 20.3 Biofiber Composites Based on PP References Chapter 21: Biodegradable Polymers as Matrix for Biocomposites 21.1 Introduction 21.2 Polyhydroxyalkanoates 21.3 Polylactic Acid 21.4 Polybutylene Adipate Terephthalate 21.5 All Green Composites References