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

      

       Contents

      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