Biobased Adhesives

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-Skodowska 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 xviiPart 1: Fundamental Aspects 11 Introduction to Naturally-Based (Bio-) Adhesives 3Manfred Dunky1.1 Introduction 31.2 Overview and Challenges For Adhesives Based on Natural Resources 61.2.1 Combined Use of Synthetic and Naturally-Based Adhesives 81.2.2 Overview on Adhesives Based on Natural Resources 91.2.3 Requirements, Limitations, and Opportunities for Wood Adhesives Based on Natural Resources 111.3 Biorefinery and Platform Chemicals 111.4 Lignin as Raw Material for Platform Chemicals 201.5 5-Hydroxymethylfurfural (5-HMF) as Platform Chemical 231.6 Mimicking Nature 271.7 Special Topics and Latest Developments 291.8 Prospects 301.9 Summary 30General Literature on Biobased Adhesives 30List of Abbreviations 34References 352 Adhesion Theories in Naturally-Based Bonding: Adhesion and Surface Issues with Naturally-Based Adhesives 45Douglas J. Gardner, Geeta Pokhrel and Alexander Collins2.1 Introduction 452.2 Adhesion Theories 462.2.1 Mechanical Interlocking 472.2.2 Electrostatic Mechanism 482.2.3 Adsorption (Thermodynamic) or Wetting Mechanism 492.2.4 Diffusion Mechanism 502.2.5 Chemical (Covalent) Bonding Mechanism 502.2.5.1 Hydrogen Bonding 512.2.6 Acid-Base Theory 512.2.7 Weak Boundary Layers 522.2.8 Stickiness or Tackiness 532.3 Protein Adhesives 542.3.1 Animal-Sourced Proteins 552.3.2 Plant Proteins 572.4 Carbohydrate-Based Adhesives 592.5 Plant or Wood-Based Extractives 602.5.1 Rubber 602.5.2 Resins 612.5.2.1 Rosin 622.5.2.2 Terpene Resins 632.5.2.3 Tannins 642.5.2.4 Gums 652.6 Fats or Oils 662.6.1 Tung Oil 672.6.2 Linseed Oil 682.6.3 Soybean Oil 692.6.4 Castor Oil 702.6.5 Miscellaneous Oils 712.7 Summary 72Acknowledgements 72List of Abbreviations 72References 743 The Chemistry of Bioadhesives 85A. Pizzi3.1 Introduction 853.2 Carbohydrate Bioadhesives 863.3 Protein Bioadhesives 913.4 Lignin-Based Bioadhesives 933.5 Tannin-Based Bioadhesives 953.5.1 Hydrolysable Tannins 963.5.1.1 Gallo-Tannins 963.5.1.2 Ellagi-Tannins 963.5.2 Condensed Polyflavonoid Tannins 963.5.3 Reactions of Condensed Flavonoid Tannins 993.6 Other Bio-Adhesives for Wood Composites 1063.7 Summary 108List of Abbreviations 109References 1104 Biorefinery Products as Naturally-Based Key Raw Materials for Adhesives 119Johannes Karl Fink4.1 Biorefinery Systems 1194.1.1 History of Biomaterials 1194.1.2 Classification of Biorefinery Systems 1204.1.3 Biorefinery Processes 1234.1.3.1 Hydrothermal Processes 1234.1.3.2 Thermochemical Processes 1234.1.3.3 Chemical Processes 1244.1.3.4 Biochemical Processes 1244.1.3.5 Bacterial Processes 1244.1.4 Renewable Materials for Biorefinery 1264.1.4.1 Carbohydrates 1264.1.4.2 Lignin 1264.1.4.3 Triglycerides 1274.1.4.4 Mixed Organic Residues 1274.2 Biobased Materials 1284.2.1 Biobased Monomers 1284.2.2 Synthesis Methods 1294.2.2.1 L-3,4-Dihydroxyphenylalanine 1354.2.2.2 2-Pyrone-4,6-dicarboxylic acid 1364.3 Biobased Materials Suitable for Adhesives 1374.3.1 Additives 1374.3.2 Wood Adhesives 1384.3.3 Lignin-Based Adhesives 1394.3.4 Biorefinery Process of Kash 1394.3.5 Lignin-Phenol Adhesives 1404.3.5.1 Enzymatic Hydrolysis of Lignin 1414.3.5.2 Biorefinery Residues 1424.3.5.3 Phenol Replacement by Lignins 1424.3.6 Lignin-Epoxy Adhesives 1434.3.7 Lignosulfonates 1454.3.8 Tannins 1454.3.9 Protein-Based Adhesives 1464.4 Synthesis Methods for Biobased Adhesives 1474.4.1 Methylolated Wood-Derived Bio-Oil 1474.4.2 Biosynthesis of Lignin 1484.4.3 Soy-Based Adhesives 1494.4.4 Bisphenol A-Glycidyl Methacrylate Replacement 1494.5 Modification of Lignin for Better Performance 1504.5.1 Functionalization with Aromatic Compounds 1524.5.1.1 Functionalization of Lignin 1534.5.1.2 Phenolation of Lignin 1544.5.2 Organosolv Lignin-Based Materials 1554.6 Pressure-Sensitive Adhesives 1554.6.1 Lignin as Filler 1564.6.2 Biobased Acrylic Compounds 1564.6.3 UV-Tunable Pressure-Sensitive Adhesives 1574.7 Summary 158References 1585 Natural Aldehyde-Based Thermosetting Resins 167Manfred Dunky5.1 Introduction 1675.2 Aliphatic Aldehydes 1685.2.1 Acetaldehyde 1685.2.2 Glyoxal 1695.2.2.1 Glyoxalation of Lignin 1715.2.2.2 Glyoxylic Acid and Glyoxal 1765.2.2.3 Glyoxal and Glutaraldehyde 1765.2.2.4 Glyoxal and 5-Hydroxymethylfurfural (5-HMF) 1775.2.3 Dimethoxy-Ethanal (Dimethoxy-Acetaldehyde, DME) 1775.2.4 Propanal (Propionaldehyde) 1785.2.5 Butyraldehyde 1785.2.6 Isobutyraldehyde (Isobutanal) 1795.2.7 Succinaldehyde (Butandial) 1795.2.8 Glutar(di)aldehyde (GA) (Pentandial) 1805.3 Aldehydes Based on Cyclic Structures 1805.3.1 Furfural (Furfurylaldehyde) 1805.3.2 Furfuryl Alcohol (FA) 1845.3.3 5-Hydroxymethylfurfural (5-HMF) (see also Chapters 1 and 17) 1855.3.4 2,5-Diformylfuran (2,5-Furan-Dicarbaldehyde) 1925.3.5 Aromatic Aldehyde Precursors 1935.3.6 Polymers with Pendent Aldehyde Groups 1945.4 Summary 195List of Abbreviations 195References 1986 Natural Crosslinkers for Naturally-Based Adhesives 207Manfred Dunky6.1 Introduction 2076.2 Crosslinking Reactions 2086.2.1 Proteins 2086.2.2 Tannins 2116.2.3 Carbohydrates 2146.2.4 Lignins 2176.3 Aliphatic Aldehydes as Crosslinkers 2196.3.1 Formaldehyde 2196.3.2 Higher Aldehydes 2216.3.3 Glyoxal 2216.3.4 Glutaraldehyde 2236.3.5 Higher Aliphatic Aldehydes 2266.4 Cyclic and Aromatic Aldehydes as Crosslinkers 2266.4.1 Furfural 2266.4.2 5-Hydroxymethylfurfural (5-HMF) 2286.4.3 Non-Volatile Aldehydes from Carbohydrates 2306.5 Crosslinkers Prepared from Biomass 2316.5.1 Furfuryl Alcohol 2316.5.2 Extracts as Crosslinkers 2346.5.3 Glycerol Diglycidyl Ether (GDE), Glycerol Polyglycidyl Ether (GPE), and Ethylene Glycol Diglycidyl Ether (EGDE) 2346.5.4 Triglycidylamine (TGA) 2366.5.5 Diethylene-Triamine (DETA) 2376.5.6 Citric Acid 2376.6 Synthetic Crosslinkers 2406.6.1 Polyamidoamine–Epichlorohydrin (PAE) Resins 2406.6.2 Epoxy Resins 2416.6.3 Polyethylenimine (PEI) 2426.6.4 Polyamidoamine (PADA) 243List of Abbreviations 243References 2457 Curing and Adhesive Bond Strength Development in Naturally-Based Adhesives 255Milan Šernek and Jure Žigon7.1 Introduction 2557.2 Curing Monitoring Techniques 2567.2.1 Gel Time Test 2567.2.2 Differential Scanning Calorimetry (DSC) 2577.2.3 Thermogravimetric Analysis (TGA) 2587.2.4 Dielectric Analysis (DEA) 2597.3 Bond Strength Development Monitoring Techniques 2607.3.1 Dynamic Mechanical Analysis (DMA) 2607.3.2 Thermomechanical Analysis (TMA) 2617.3.3 Automated Bonding Evaluation System (ABES) 2627.3.4 Tensile-Shear Strength 2637.4 Curing Mechanisms in Naturally-Based Adhesives 2637.4.1 Tannin-Based Adhesives 2637.4.2 Lignin-Based Adhesives 2657.4.3 Soy-Based Adhesives 2677.4.4 Sucrose-Based Adhesives 2697.4.5 Starch-Based Adhesives 2707.4.6 Liquefied Wood (LW)-Based Adhesives 2717.5 Summary 272Acknowledgements 273List of Abbreviations 273References 2748 Mimicking Nature: Bio-Inspired Adhesives 279Manfred Dunky8.1 Introduction 2798.2 Improvement of Adhesive Performance 2828.3 Underwater Adhesives (Wet Application Adhesives) 2868.4 Detechable Bonding and Self-Healing Polymers 2898.5 Medical Applications 2928.6 Summary 294List of Abbreviations 294References 295Part 2: Classes of Biobased Adhesives 3059 Protein Adhesives – Composition, Structure and Performance 307Charles R. Frihart9.1 Introduction 3079.2 Composition of Proteins 3089.3 Types, Sources, Processing, and Properties of Proteins 3099.3.1 Collagen (Animal) 3099.3.2 Globular (Plant) 3119.3.3 Globular (Milk) 3159.3.4 Globular (Egg) 3169.3.5 Globular (Blood) 3179.3.6 Other Protein Sources 3179.4 Conclusion (Future of Protein Adhesives) and Summary 317List of Abbreviations 318References 31910 Carbohydrates (Polysaccharides) as Adhesives 325Lee Seng Hua and Lum Wei Chen10.1 Introduction 32510.2 Cellulose Derivatives 32610.3 Starch-Based Adhesives 33010.4 Dextrin 33110.5 Natural Gums 33310.6 Chitosan 33510.7 Summary and Prospects 339Acknowledgements 340List of Abbreviations 340References 34111 Natural Polymer-Based Adhesives 345A.A. Shybi, Siby Varghese, Hanna J. Maria and Sabu Thomas11.1 Introduction 34511.2 Natural Rubber (NR)-Based Adhesives 34611.2.1 Introduction to NR-Based Adhesives 34611.2.2 NR-Based Wood Adhesives 35011.2.3 NR-Based Pressure-Sensitive Adhesives 35211.2.4 NR-Based Adhesives in Leather, Rubber, Textile and Metal Bonding Applications 35311.3 Poly(lactic acid) (PLA)-Based Wood Adhesives 35411.3.1 Introduction to PLA-Based Adhesives 35411.3.2 PLA-Based Wood Adhesives 35511.3.3 PLA-Based Hot-Melt Adhesives 35611.3.4 PLA-Based Adhesives for Metal Bonding 35711.4 Chitosan-Based Adhesives 35711.4.1 Introduction to Chitosan-Based Adhesives 35711.4.2 Chitosan-Based Wood Adhesives 35811.5 Summary 359List of Abbreviations 360References 36112 Epoxy Adhesives from Natural Materials 367Charles R. Frihart12.1 Introduction and Morphology 36712.2 Basic Properties of Epoxies 36912.3 Epoxy Synthesis 37012.4 Epoxy Curing 37312.4.1 One-Component Epoxies 37512.4.2 Two-Component Epoxies 37612.5 Aromatic Epoxies 37612.5.1 Aromatic Bis-Phenol Epoxies 37612.5.2 Aromatic Novolac Epoxies 37712.5.3 Biobased Aromatic Epoxies from Polyphenols, Tannins, Cardanol, and Lignin 37812.5.4 Aromatic Epoxies from Lignin and Woody Biomass 37812.6 Aliphatic Epoxies 37912.6.1 Aliphatic Epoxies from Vegetable Oils 38012.6.2 Aliphatic Epoxies from Sugars 38112.6.3 Aliphatic Epoxies from Terpenoids 38212.6.4 Other Aliphatic Epoxies 38212.7 Hardeners 38312.7.1 Amines 38312.7.1.1 Aliphatic Amines 38312.7.1.2 Biobased Aliphatic Amines 38412.7.1.3 Aromatic Amines 38512.7.2 Anhydrides of Organic Acids 38612.8 Other Curing Mechanisms 38612.9 Other Additives 38612.9.1 Tougheners 38612.9.2 Modifiers 38712.10 Status of Biobased Epoxy Adhesives 38712.11 Summary 388List of Abbreviations 389References 38913 Naturally-Based Polyurethane Bioadhesives 395A. Pizzi13.1 Introduction 39513.2 Biopolyols-Isocyanate Polyurethanes 39613.3 Non-Isocyanate Polyurethanes (NIPUs) 39913.4 NIPUs as Adhesives 40213.5 Summary 408References 40814 Nanocellulose-Modified Wood Adhesives 415Stefan Veigel, Stefan Pinkl and Wolfgang Gindl-Altmutter14.1 Introduction 41514.2 Nanocellulose as Additive for Conventional and Biobased Wood Adhesives 41614.3 Nanocellulose-Derived Wood Adhesives 42014.4 Prospects 42114.5 Summary 421Note 422List of Abbreviations 422References 42315 Debondable, Recyclable and/or Biodegradable Naturally-Based Adhesives 427Natanel Jarach and Hanna Dodiuk15.1 Introduction 42715.2 Debondable Adhesives 42815.2.1 Types of Debonding Adhesives 42815.2.2 Reversible Covalent Bonds Containing Adhesives 42915.3 Biobased Debondable and Recyclable Adhesives 43115.3.1 Biodegradable Adhesives 43115.3.2 Biobased Reversible Covalent Bonds Containing Adhesives 43815.4 Summary 453List of Abbreviations 453References 45416 Fungal Mycelia as Bioadhesives 463Wenjing Sun, Mehdi Tajvidi and Christopher G. Hunt16.1 Introduction 46316.2 Basics of Fungal Mycelia 46416.2.1 Fungal Species 46416.2.2 Fungal Cell Wall 46416.2.3 Effects of Fungal Mycelia on Lignocellulosic Substrates 46516.3 Production Procedure 46516.4 Adhesive Performance 46716.4.1 As-Grown Foams 46716.4.2 Hot-Pressed Panels 47016.4.3 Engineered Living Materials 47016.5 Improvement Strategies 47016.5.1 Incorporating Natural Fibers 47116.5.2 Infusing Bio-Resin 47116.5.3 Incorporating Natural Reinforcement Particles 47116.6 Prospects 47116.7 Summary 471Acknowledgements 472List of Abbreviations 472References 47217 5-Hydroxymethylfurfural-Based Adhesives: Challenges and Opportunities 477Wilfried Sailer-Kronlachner, Catherine Rosenfeld, Johannes Konnerth and Hendrikus van Herwijnen17.1 Introduction 47717.2 5-Hydroxymethylfurfural as Biobased Platform Chemical 47917.2.1 Potential as Chemical Building Block 47917.2.2 Challenges in the Implementation of an Industrial 5-HMF Production 48017.3 5-HMF-Based Adhesive Systems 48317.3.1 Wood Adhesives 48417.3.2 Non-Wood Applications of 5-HMF-Based Adhesives 48717.3.3 Examples of Adhesives Produced from 5-HMF Derivatives 48817.4 Prospects 49017.5 Summary 491Acknowledgements 491List of Abbreviations 492References 49218 Adhesive Precursors from Tree-Derived Naval Stores 499Charles R. Frihart18.1 Introduction 49918.2 Sources and Structures 50018.2.1 Rosins 50018.2.2 Fatty Acids 50218.2.3 Terpenes 50318.3 Pressure-Sensitive Adhesives 50318.4 Chemistry and Products 50518.4.1 Rosins 50518.4.2 Modification of the Carboxylic Acid 50618.4.3 Modification of the Olefinic Portion 50818.4.4 Ink Pigment Binders 50918.4.5 Tall Oil Fatty Acids 51018.4.6 Terpenes 51218.5 Summary 513List of Abbreviations 513References 513Part 3: Applications of Biobased Adhesives 51719 Naturally-Based Adhesives for Wood and Wood-Based Panels 519Manfred Dunky19.1 Introduction 51919.2 Protein-Based Wood Adhesives 52119.2.1 Wood Bonding with Proteins 52219.2.2 Plant-Based Proteins (for Soy Proteins see Section 19.2.3) 52419.2.3 Soy Proteins 52519.2.4 Animal-Based Proteins 52819.2.5 Denaturation and Modification of Proteins 53119.2.6 Crosslinking of Proteins 53419.3 Wood Adhesives Based on Carbohydrates 53519.3.1 Types and Sources of Carbohydrates for Use as Wood Adhesives 53519.3.2 Modification of Starch for Possible Use as Wood Adhesive 53719.3.3 Combination and Crosslinking of Carbohydrates with Natural and Synthetic Components 53919.3.4 Degradation and Repolymerization of Carbohydrates 53919.4 Tannin-Based Wood Adhesives 53919.4.1 Types and Chemistry of Condensed Tannins 54019.4.2 Hardening and Crosslinking of Tannins 54219.4.3 Combination of Tannins with Other Components 54619.5 Wood Adhesives Based on Lignin 54719.5.1 Chemistry and Structure of Lignin 54719.5.2 Modification of Lignin 54819.5.3 Lignin as Adhesive 55219.5.4 Lignin as Sole Adhesive 55419.5.5 Reactions of Lignin with Various Aldehydes and Other Naturally-Based Components 55719.6 Summary 558List of Abbreviations 558References 55920 Activation of Wood Surfaces and “Binderless” Wood Composites 579Manfred Dunky20.1 Introduction 57920.2 Self-Adhesion and “Binderless” Boards 58420.2.1 Wood and Non-Wood Components for “Binderless” Boards 58620.2.2 Thermal and Physical Pretreatments of Wood Material and the Wood Surface 58920.2.3 Chemical Treatments of the Wood Surface 59120.2.4 Enzymatic Pretreatment of the Wood Surface 59520.2.5 Degradation and Re-Polymerization of Carbohydrates 59820.2.6 Citric Acid 60120.2.6.1 Sugars and Starch in Combination with Citric Acid 60120.2.6.2 Wood in Combination with Citric Acid 60220.2.7 Hardboards (Wet Fiber Process) 60520.2.8 Wood Welding 60720.3 Summary 611List of Abbreviations 611References 61221 Bonding of Solid Wood-Based Materials for Timber Construction 621Peter Niemz and Manfred Dunky21.1 Introduction 62121.2 Brief Overview of Solid Wood-Based Materials 62221.3 Adhesives Used for Materials in Structural Timber Engineering 62521.3.1 Adhesives for the Production of Glued-Laminated Timber (Surface Bonding) 62521.3.2 Casein Adhesives 62821.4 Factors Influencing the Quality of Adhesively-Bonded Wood 63121.4.1 Short Overview 63121.4.2 Influence of the Wood Substrate (Structure and Wood Species) 63121.4.3 Influence of Adhesives 63621.4.4 Influence of Wood Machining 64321.4.5 Quality Control of Bonded Wood Joints 64421.4.6 Influence of Service Conditions 64421.4.7 Aging of Bonded Wood 64621.5 Trends in the Use of Biobased Adhesives 64921.6 Summary 650List of Abbreviations 651References 65222 Applications and Industrial Implementations of Naturally-Based Adhesives 659Manfred Dunky22.1 Introduction 65922.2 Wood-Based Panels 66022.3 Shoe Fabrication (Footwear Industry) 66422.4 Bonding of Metals 66622.5 Composites in Automotive, Aircraft, and Aeronautical Industries 66722.6 Natural Composites with Matrices Based on Natural Resources 67322.7 Mineral Wool 67922.8 Packaging and Other Applications 67922.9 Biomedical Applications 68022.10 Biodegradability and Recycling 68122.11 Life Cycle Analysis (LCA) 68322.12 Summary 686List of Abbreviations 686References 68823 Bioadhesives for the Advancement of Controlled Drug Delivery and Wearable Bioelectronics 705Monalisha Ghosh Dastidar, Sharmili Roy and Sudarsan Neogi23.1 Introduction 70523.1.1 History of Bioadhesives and their Evolution 70623.1.2 Classification of Bioadhesives 70623.1.2.1 Natural Bioadhesives 70723.1.2.2 Biological and Biocompatible Bioadhesives 70723.1.2.3 Biomimetic and Bioinspired Bioadhesives 70723.1.3 Mechanism of Bioadhesives 70823.2 Bioadhesives in Controlled Drug Delivery 70823.3 Bioadhesives in Bioelectronics 71023.4 Limitations of Bioadhesives for Biomedical Applications 71723.5 Summary and Future Prospects 718List of Abbreviations 719References 720Index 727