Manfred Dunky, PhD, has spent a 40-year career in the chemical and wood-based panels industry as a researcher and consultant. During the last 25 years, he has placed an emphasis on adhesives based on natural resources. Besides his industry career, in 2000 he received his habilitation (post-doctoral lecturing qualification) for "Wood Science with special consideration of wood-based panels" and was a lecturer at several universities. He is invited regularly to speak at many wood science conferences.

Kashmiri Lal Mittal was employed by the IBM Corporation from 1972 through 1993. Currently, he is teaching and consulting worldwide in the broad areas of adhesion, as well as surface cleaning. He has received numerous awards and honors, including the title of doctor honoris causa from Maria Curie-Sk³odowska University, Lublin, Poland. He is the editor of over 150 books dealing with adhesion measurement, adhesion of polymeric coatings, polymer surfaces, adhesive joints, adhesion promoters, thin films, polyimides, surface modification surface cleaning, and surfactants.

Preface xvii Part 1: Fundamental Aspects 1 1 Introduction to Naturally-Based (Bio-) Adhesives 3Manfred Dunky 1.1 Introduction 3 1.2 Overview and Challenges For Adhesives Based on Natural Resources 6 1.2.1 Combined Use of Synthetic and Naturally-Based Adhesives 8 1.2.2 Overview on Adhesives Based on Natural Resources 9 1.2.3 Requirements, Limitations, and Opportunities for Wood Adhesives Based on Natural Resources 11 1.3 Biorefinery and Platform Chemicals 11 1.4 Lignin as Raw Material for Platform Chemicals 20 1.5 5-Hydroxymethylfurfural (5-HMF) as Platform Chemical 23 1.6 Mimicking Nature 27 1.7 Special Topics and Latest Developments 29 1.8 Prospects 30 1.9 Summary 30 General Literature on Biobased Adhesives 30 List of Abbreviations 34 References 35 2 Adhesion Theories in Naturally-Based Bonding: Adhesion and Surface Issues with Naturally-Based Adhesives 45Douglas J. Gardner, Geeta Pokhrel and Alexander Collins 2.1 Introduction 45 2.2 Adhesion Theories 46 2.2.1 Mechanical Interlocking 47 2.2.2 Electrostatic Mechanism 48 2.2.3 Adsorption (Thermodynamic) or Wetting Mechanism 49 2.2.4 Diffusion Mechanism 50 2.2.5 Chemical (Covalent) Bonding Mechanism 50 2.2.5.1 Hydrogen Bonding 51 2.2.6 Acid-Base Theory 51 2.2.7 Weak Boundary Layers 52 2.2.8 Stickiness or Tackiness 53 2.3 Protein Adhesives 54 2.3.1 Animal-Sourced Proteins 55 2.3.2 Plant Proteins 57 2.4 Carbohydrate-Based Adhesives 59 2.5 Plant or Wood-Based Extractives 60 2.5.1 Rubber 60 2.5.2 Resins 61 2.5.2.1 Rosin 62 2.5.2.2 Terpene Resins 63 2.5.2.3 Tannins 64 2.5.2.4 Gums 65 2.6 Fats or Oils 66 2.6.1 Tung Oil 67 2.6.2 Linseed Oil 68 2.6.3 Soybean Oil 69 2.6.4 Castor Oil 70 2.6.5 Miscellaneous Oils 71 2.7 Summary 72 Acknowledgements 72 List of Abbreviations 72 References 74 3 The Chemistry of Bioadhesives 85A. Pizzi 3.1 Introduction 85 3.2 Carbohydrate Bioadhesives 86 3.3 Protein Bioadhesives 91 3.4 Lignin-Based Bioadhesives 93 3.5 Tannin-Based Bioadhesives 95 3.5.1 Hydrolysable Tannins 96 3.5.1.1 Gallo-Tannins 96 3.5.1.2 Ellagi-Tannins 96 3.5.2 Condensed Polyflavonoid Tannins 96 3.5.3 Reactions of Condensed Flavonoid Tannins 99 3.6 Other Bio-Adhesives for Wood Composites 106 3.7 Summary 108 List of Abbreviations 109 References 110 4 Biorefinery Products as Naturally-Based Key Raw Materials for Adhesives 119Johannes Karl Fink 4.1 Biorefinery Systems 119 4.1.1 History of Biomaterials 119 4.1.2 Classification of Biorefinery Systems 120 4.1.3 Biorefinery Processes 123 4.1.3.1 Hydrothermal Processes 123 4.1.3.2 Thermochemical Processes 123 4.1.3.3 Chemical Processes 124 4.1.3.4 Biochemical Processes 124 4.1.3.5 Bacterial Processes 124 4.1.4 Renewable Materials for Biorefinery 126 4.1.4.1 Carbohydrates 126 4.1.4.2 Lignin 126 4.1.4.3 Triglycerides 127 4.1.4.4 Mixed Organic Residues 127 4.2 Biobased Materials 128 4.2.1 Biobased Monomers 128 4.2.2 Synthesis Methods 129 4.2.2.1 L-3,4-Dihydroxyphenylalanine 135 4.2.2.2 2-Pyrone-4,6-dicarboxylic acid 136 4.3 Biobased Materials Suitable for Adhesives 137 4.3.1 Additives 137 4.3.2 Wood Adhesives 138 4.3.3 Lignin-Based Adhesives 139 4.3.4 Biorefinery Process of Kash 139 4.3.5 Lignin-Phenol Adhesives 140 4.3.5.1 Enzymatic Hydrolysis of Lignin 141 4.3.5.2 Biorefinery Residues 142 4.3.5.3 Phenol Replacement by Lignins 142 4.3.6 Lignin-Epoxy Adhesives 143 4.3.7 Lignosulfonates 145 4.3.8 Tannins 145 4.3.9 Protein-Based Adhesives 146 4.4 Synthesis Methods for Biobased Adhesives 147 4.4.1 Methylolated Wood-Derived Bio-Oil 147 4.4.2 Biosynthesis of Lignin 148 4.4.3 Soy-Based Adhesives 149 4.4.4 Bisphenol A-Glycidyl Methacrylate Replacement 149 4.5 Modification of Lignin for Better Performance 150 4.5.1 Functionalization with Aromatic Compounds 152 4.5.1.1 Functionalization of Lignin 153 4.5.1.2 Phenolation of Lignin 154 4.5.2 Organosolv Lignin-Based Materials 155 4.6 Pressure-Sensitive Adhesives 155 4.6.1 Lignin as Filler 156 4.6.2 Biobased Acrylic Compounds 156 4.6.3 UV-Tunable Pressure-Sensitive Adhesives 157 4.7 Summary 158 References 158 5 Natural Aldehyde-Based Thermosetting Resins 167Manfred Dunky 5.1 Introduction 167 5.2 Aliphatic Aldehydes 168 5.2.1 Acetaldehyde 168 5.2.2 Glyoxal 169 5.2.2.1 Glyoxalation of Lignin 171 5.2.2.2 Glyoxylic Acid and Glyoxal 176 5.2.2.3 Glyoxal and Glutaraldehyde 176 5.2.2.4 Glyoxal and 5-Hydroxymethylfurfural (5-HMF) 177 5.2.3 Dimethoxy-Ethanal (Dimethoxy-Acetaldehyde, DME) 177 5.2.4 Propanal (Propionaldehyde) 178 5.2.5 Butyraldehyde 178 5.2.6 Isobutyraldehyde (Isobutanal) 179 5.2.7 Succinaldehyde (Butandial) 179 5.2.8 Glutar(di)aldehyde (GA) (Pentandial) 180 5.3 Aldehydes Based on Cyclic Structures 180 5.3.1 Furfural (Furfurylaldehyde) 180 5.3.2 Furfuryl Alcohol (FA) 184 5.3.3 5-Hydroxymethylfurfural (5-HMF) (see also Chapters 1 and 17) 185 5.3.4 2,5-Diformylfuran (2,5-Furan-Dicarbaldehyde) 192 5.3.5 Aromatic Aldehyde Precursors 193 5.3.6 Polymers with Pendent Aldehyde Groups 194 5.4 Summary 195 List of Abbreviations 195 References 198 6 Natural Crosslinkers for Naturally-Based Adhesives 207Manfred Dunky 6.1 Introduction 207 6.2 Crosslinking Reactions 208 6.2.1 Proteins 208 6.2.2 Tannins 211 6.2.3 Carbohydrates 214 6.2.4 Lignins 217 6.3 Aliphatic Aldehydes as Crosslinkers 219 6.3.1 Formaldehyde 219 6.3.2 Higher Aldehydes 221 6.3.3 Glyoxal 221 6.3.4 Glutaraldehyde 223 6.3.5 Higher Aliphatic Aldehydes 226 6.4 Cyclic and Aromatic Aldehydes as Crosslinkers 226 6.4.1 Furfural 226 6.4.2 5-Hydroxymethylfurfural (5-HMF) 228 6.4.3 Non-Volatile Aldehydes from Carbohydrates 230 6.5 Crosslinkers Prepared from Biomass 231 6.5.1 Furfuryl Alcohol 231 6.5.2 Extracts as Crosslinkers 234 6.5.3 Glycerol Diglycidyl Ether (GDE), Glycerol Polyglycidyl Ether (GPE), and Ethylene Glycol Diglycidyl Ether (EGDE) 234 6.5.4 Triglycidylamine (TGA) 236 6.5.5 Diethylene-Triamine (DETA) 237 6.5.6 Citric Acid 237 6.6 Synthetic Crosslinkers 240 6.6.1 Polyamidoamine-Epichlorohydrin (PAE) Resins 240 6.6.2 Epoxy Resins 241 6.6.3 Polyethylenimine (PEI) 242 6.6.4 Polyamidoamine (PADA) 243 List of Abbreviations 243 References 245 7 Curing and Adhesive Bond Strength Development in Naturally-Based Adhesives 255Milan Šernek and Jure ?igon 7.1 Introduction 255 7.2 Curing Monitoring Techniques 256 7.2.1 Gel Time Test 256 7.2.2 Differential Scanning Calorimetry (DSC) 257 7.2.3 Thermogravimetric Analysis (TGA) 258 7.2.4 Dielectric Analysis (DEA) 259 7.3 Bond Strength Development Monitoring Techniques 260 7.3.1 Dynamic Mechanical Analysis (DMA) 260 7.3.2 Thermomechanical Analysis (TMA) 261 7.3.3 Automated Bonding Evaluation System (ABES) 262 7.3.4 Tensile-Shear Strength 263 7.4 Curing Mechanisms in Naturally-Based Adhesives 263 7.4.1 Tannin-Based Adhesives 263 7.4.2 Lignin-Based Adhesives 265 7.4.3 Soy-Based Adhesives 267 7.4.4 Sucrose-Based Adhesives 269 7.4.5 Starch-Based Adhesives 270 7.4.6 Liquefied Wood (LW)-Based Adhesives 271 7.5 Summary 272 Acknowledgements 273 List of Abbreviations 273 References 274 8 Mimicking Nature: Bio-Inspired Adhesives 279Manfred Dunky 8.1 Introduction 279 8.2 Improvement of Adhesive Performance 282 8.3 Underwater Adhesives (Wet Application Adhesives) 286 8.4 Detechable Bonding and Self-Healing Polymers 289 8.5 Medical Applications 292 8.6 Summary 294 List of Abbreviations 294 References 295 Part 2: Classes of Biobased Adhesives 305 9 Protein Adhesives - Composition, Structure and Performance 307Charles R. Frihart 9.1 Introduction 307 9.2 Composition of Proteins 308 9.3 Types, Sources, Processing, and Properties of Proteins 309 9.3.1 Collagen (Animal) 309 9.3.2 Globular (Plant) 311 9.3.3 Globular (Milk) 315 9.3.4 Globular (Egg) 316 9.3.5 Globular (Blood) 317 9.3.6 Other Protein Sources 317 9.4 Conclusion (Future of Protein Adhesives) and Summary 317 List of Abbreviations 318 References 319 10 Carbohydrates (Polysaccharides) as Adhesives 325Lee Seng Hua and Lum Wei Chen 10.1 Introduction 325 10.2 Cellulose Derivatives 326 10.3 Starch-Based Adhesives 330 10.4 Dextrin 331 10.5 Natural Gums 333 10.6 Chitosan 335 10.7 Summary and Prospects 339 Acknowledgements 340 List of Abbreviations 340 References 341 11 Natural Polymer-Based Adhesives 345A.A. Shybi, Siby Varghese, Hanna J. Maria and Sabu Thomas 11.1 Introduction 345 11.2 Natural Rubber (NR)-Based Adhesives 346 11.2.1 Introduction to NR-Based Adhesives 346 11.2.2 NR-Based Wood Adhesives 350 11.2.3 NR-Based Pressure-Sensitive Adhesives 352 11.2.4 NR-Based Adhesives in Leather, Rubber, Textile and Metal Bonding Applications 353 11.3 Poly(lactic acid) (PLA)-Based Wood Adhesives 354 11.3.1 Introduction to PLA-Based Adhesives 354 11.3.2 PLA-Based Wood Adhesives 355 11.3.3 PLA-Based Hot-Melt Adhesives 356 11.3.4 PLA-Based Adhesives for Metal Bonding 357 11.4 Chitosan-Based Adhesives 357 11.4.1 Introduction to Chitosan-Based Adhesives 357 11.4.2 Chitosan-Based Wood Adhesives 358 11.5 Summary 359 List of Abbreviations 360 References 361 12 Epoxy Adhesives from Natural Materials 367Charles R. Frihart 12.1 Introduction and Morphology 367 12.2 Basic Properties of Epoxies 369 12.3 Epoxy Synthesis 370 12.4 Epoxy Curing 373 12.4.1 One-Component Epoxies 375 12.4.2 Two-Component Epoxies 376 12.5 Aromatic Epoxies 376 12.5.1 Aromatic Bis-Phenol Epoxies 376 12.5.2 Aromatic Novolac Epoxies 377 12.5.3 Biobased Aromatic Epoxies from Polyphenols, Tannins, Cardanol, and Lignin 378 12.5.4 Aromatic Epoxies from Lignin and Woody Biomass 378 12.6 Aliphatic Epoxies 379 12.6.1 Aliphatic Epoxies from Vegetable Oils 380 12.6.2 Aliphatic Epoxies from Sugars 381 12.6.3 Aliphatic Epoxies from Terpenoids 382 12.6.4 Other Aliphatic Epoxies 382 12.7 Hardeners 383 12.7.1 Amines 383 12.7.1.1 Aliphatic Amines 383 12.7.1.2 Biobased Aliphatic Amines 384 12.7.1.3 Aromatic Amines 385 12.7.2 Anhydrides of Organic Acids 386 12.8 Other Curing Mechanisms 386 12.9 Other Additives 386 12.9.1 Tougheners 386 12.9.2 Modifiers 387 12.10 Status of Biobased Epoxy Adhesives 387 12.11 Summary 388 List of Abbreviations 389 References 389 13 Naturally-Based Polyurethane Bioadhesives 395A. Pizzi 13.1 Introduction 395...