Progress in Adhesion and Adhesives, Volume 6

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-Skłodowska University, Lublin, Poland. He is the editor of more than 140 books dealing with adhesion measurement, adhesion of polymeric coatings, polymer surfaces, adhesive joints, adhesion promoters, thin films, polyimides, surface modification surface cleaning, and surfactants. Dr. Mittal is also the Founding Editor of the journal Reviews of Adhesion and Adhesives.

• Preface xxi1 Hot-Melt Adhesives: Fundamentals, Formulations, and Applications: A Critical Review 1Swaroop Gharde, Gaurav Sharma and Balasubramanian Kandasubramanian1.1 Introduction to Hot-Melt Adhesives (HMAs) 21.2 Formulation of Hot-Melt Adhesives 41.2.1 Theories or Mechanisms of Adhesion 41.2.1.1 Mechanical Interlocking Theory 41.2.1.2 Electrostatic Theory 51.2.1.3 Diffusion Theory 51.2.1.4 Physical Adsorption or Wetting Theory 51.2.1.5 Chemical Bonding 51.2.2 Intermolecular Forces between Adhesives and Adherend 51.2.3 Thermodynamic Model of Adhesion 61.2.4 Bonded Joints 71.2.5 Surface Preparation for HMA Application 81.2.5.1 Solvent Degreasing 91.2.5.2 Chemically-Active Surface 91.3 Fundamental Aspects of Adhesive Behavior of HMAs 101.3.1 Mechanical and Physical Behaviors 101.3.2 Blending Behavior and the Effects of Other Ingredients 111.3.3 Polymeric Behavior 121.4 Preparation of HMAs Using Various Polymers 121.4.1 HMAs by Grafting Acrylic and Crotonic Acids on Metallocene Ethylene-Octene Polymers 121.4.1.1 Solution Grafting 131.4.1.2 Melt Grafting 141.4.1.3 Preparation of HMAs 141.4.2 Cross-Linked Polyurethane Hot-Melt Adhesives (PUR-HMAs) 141.4.3 Soybean Protein Isolate and Polycaprolactone Based HMAs (SPIP-HMAs) 151.5 Mechanical Analysis of Hot-Melt Adhesives 161.5.1 Fracture Mechanics of HMAs 161.5.1.1 Fracture Energy Measurement 181.5.2 Stress-Strain, and Frequency-Temperature Sweep Tests for Viscoelasticity 181.6 Industrial Applications of Hot-Melt Adhesives 201.6.1 Medical Applications 201.6.2 Electronic Applications 211.6.3 Anticorrosion Applications 211.6.4 Food Packaging Applications 211.6.5 Textile Applications 221.7 Current Challenges and Future Scope of HMAs 221.8 Summary 23Acknowledgment 24References 242 Optimization of Adhesively Bonded Spar-Wingskin Joints of Laminated FRP Composites Subjected to Pull-Off Load: A Critical Review 29S. Rakshe, S. V. Nimje and S. K. Panigrahi2.1 Introduction 292.2 Finite Element Analysis of SWJ 312.2.1 Geometry and Configuration 312.2.2 Finite Element Modeling 322.2.3 Validation and Convergence Study 332.3 Taguchi Method of Optimization 342.3.1 Optimization of Material and Lamination Scheme 352.3.2 Geometrical Parameter 362.4 Results and Discussion 382.4.1 Material and Lamination Scheme 382.4.1.1 Analysis of Variance (ANOVA) 392.4.2 Geometrical Parameter 412.4.2.1 Analysis of Variance (ANOVA) 422.5 Conclusions 44References 453 Contact Angle Hysteresis – Advantages and Disadvantages: A Critical Review 47Andrew Terhemen Tyowua and Stephen Gbaoron Yiase3.1 Introduction 473.2 Contact Angle and Hysteresis Measurement 493.2.1 Theoretical Treatment of Static Contact Angles 513.2.2 Modeling of Dynamic Contact Angles 533.2.3 Modelling Contact Angle Hysteresis 573.3 Advantages of Contact Angle Hysteresis 593.4 Disadvantages of Contact Angle Hysteresis 593.5 Summary 613.6 Acknowledgements 62References 624 Test Methods for Fibre/Matrix Adhesion in Cellulose Fibre-Reinforced Thermoplastic Composite Materials: A Critical Review 69J. Müssig and N. Graupner4.1 Introduction 704.2 Terms and Definitions 704.2.1 Fibres 714.2.2 Fibre Bundle 714.2.3 Equivalent Diameter 724.2.4 Critical Length 724.2.5 Aspect Ratio and Critical Aspect Ratio 724.2.6 Single Element versus Collective 734.2.7 Interface and Interphase 754.2.8 Adhesion and Adherence 754.2.9 Practical & Theoretical Fibre/Matrix Adhesion 754.3 Test Methods for Fibre/Matrix Adhesion 764.3.1 Overview 764.3.2 Single Fibre/Single Fibre Bundle Tests 774.3.2.1 Pull-Out Test 774.3.2.2 Microbond Test 884.3.3 Test Procedures for Fibre/Matrix Adhesion 914.3.3.1 Pull-Out Test 924.3.3.2 Microbond Test 934.3.3.3 Evaluation of Characteristic Values from Pull-Out and Microbond Tests 944.3.3.4 Fragmentation Test 984.4 Comparison of IFSS Data 1034.5 Influence of Fibre Treatment on the IFSS 1074.6 Summary 118Acknowledgements 119References 1195 Bioadhesives in Biomedical Applications: A Critical Review 131Aishee Dey, Proma Bhattacharya and Sudarsan Neogi5.1 Introduction 1315.2 Theories of Bioadhesion 1325.2.1 Factors Affecting Bioadhesion 1345.3 Different Polymers Used as Bioadhesives 1345.3.1 Collagen-Based Bioadhesives 1355.3.2 Chitosan-Based Bioadhesives 1375.3.3 Albumin-Based Bioadhesives 1385.3.4 Dextran-Based Bioadhesives 1395.3.5 Gelatin-Based Bioadhesives 1405.3.6 Poly(ethylene glycol)-Based Bioadhesives 1425.3.7 Poly(acrylic acid)-Based Bioadhesives 1425.3.8 Poly(lactic-co-glycolic acid) (PLGA)-Based Bioadhesives 1455.4 Summary 147References 1486 Mucoadhesive Pellets for Drug Delivery Applications: A Critical Review 155Inderbir Singh, Gayatri Devi, Bibhuti Ranjan Barik, Anju Sharma and Loveleen Kaur6.1 Introduction 1556.2 Mucoadhesive Polymers 1576.3 Pellets 1596.3.1 Preparation and Evaluation of Pellets 1606.3.2 Mucoadhesive Pellets for Drug Delivery Applications 1616.4 Summary and Prospects 166Conflict of Interest 166References 1667 Bio-Inspired Icephobic Coatings for Aircraft Icing Mitigation: A Critical Review 171Liqun Ma, Zichen Zhang, Linyue Gao, Yang Liu and Hui Hu7.1 Introduction 1727.2 The State-of-the-Art Icephobic Coatings/Surfaces 1747.2.1 Lotus-Leaf-Inspired Superhydrophobic Surfaces (SHS) with Micro-/Nano-Scale Surface Textures 1767.2.2 Pitcher-Plant-Inspired Slippery Liquid-Infused Porous Surfaces (SLIPS) 1777.3 Impact Icing Process Pertinent to Aircraft Inflight Icing Phenomena 1797.4 Preparation of Typical SHS and SLIPS Coatings/Surfaces 1817.5 Measurements of Ice Adhesion Strengths on Different Icephobic Coatings/Surfaces 1827.6 Icing Tunnel Testing to Evaluate the Icephobic Coatings/Surfaces for Impact Icing Mitigation 1847.7 Characterization of Rain Erosion Effects on the Icephobic Coatings 1897.8 Summary and Conclusions 196Acknowledgments 198References 1988 Wood Adhesives Based on Natural Resources: A Critical Review Part I. Protein-Based Adhesives 203Manfred DunkyList of Abbreviations 2038.1 Overview and Challenges for Wood Adhesives Based on Natural Resources 2058.1.1 Definition of Wood Adhesives Based on Natural Resources 2058.1.2 Motivation to Use Wood Adhesives Based on Natural Resources 2078.1.3 Combined Use of Synthetic and Naturally-Based Wood Adhesives 2088.1.4 Review Articles on Wood Adhesives Based on Natural Resources 2098.1.5 Motivation for this Review Article in Four Parts in the Journal “Reviews of Adhesion and Adhesives” 2118.1.6 Overview on Wood Adhesives Based on Natural Resources 2128.1.7 Requirements, Limitations, and Opportunities for Wood Adhesives Based on Natural Resources 2148.1.8 Synthetic and Natural Crosslinkers 2148.1.9 Future of Wood Adhesives Based on Natural Resources 2198.2 Protein-Based Adhesives 2228.2.1 Introduction 2228.2.1.1 Chemical Structure of Proteins 2238.2.1.2 Proteinaceous Feedstock 2248.2.1.3 Wood Bonding with Proteins 2248.2.2 Plant-Based Proteins 2288.2.2.1 Overview on Plant-Based Protein Sources and Types 2288.2.2.2 Soy Proteins 2288.2.2.3 Soy Protein as Wood Adhesive 2398.2.2.4 Thermal Treatment of Soy Proteins 2438.2.3 Animal-Based Proteins 2468.2.3.1 Types and Sources of Animal-Based Proteins 2468.2.3.2 Mussels (Marine) Proteins 2468.2.3.3 Slaughterhouse Waste as Source of Proteins 2578.2.3.4 Proteins from Specified Risk Materials (SRMs) 2608.2.4 Properties of Protein-Based Adhesives 2618.2.5 Denaturation and Modification of Proteins 2618.2.5.1 Modification of Proteins 2658.2.5.2 Crosslinking of Proteins 2658.2.6 Proteins in Combination with Other Natural Adhesives and Natural Crosslinkers 2868.2.7 Proteins in Combination with Synthetic Adhesive Resins and Crosslinkers 2868.2.8 Application of Protein-Based Wood Adhesives 2868.3 Summary 316General Literature (Overview and Review Articles) for Wood Adhesives Based on Natural Resources 316Protein-Based Adhesives 317Plant Proteins (including Soy) 318Animal Proteins and Other Sources 318References 3189 Wood Adhesives Based on Natural Resources: A Critical Review Part II. Carbohydrate-Based Adhesives 337Manfred DunkyList of Abbreviations 3379.1 Types and Sources of Carbohydrates Used as Wood Adhesives 3389.2 Modification of Starch for Possible Use as Wood Adhesive 3489.3 Citric Acid as Naturally-Based Modifier and Co-Reactant 3489.4 Combination and Crosslinking of Carbohydrates with Natural and Synthetic Components 3489.5 Degradation and Repolymerization of Carbohydrates 3489.6 Summary 373General Literature (Overview and Review Articles) for Carbohydrate-Based Adhesives 373References 37310 Wood Adhesives Based on Natural Resources: A Critical Review Part III. Tannin- and Lignin-Based Adhesives 383Manfred DunkyList of Abbreviations 38410.1 Introduction 38510.2 Tannin-Based Adhesives 38510.2.1 Chemistry of Condensed Tannins 38610.2.2 Types of Condensed Tannins 39010.2.3 Extraction, Purification, and Modification Methods for Tannins 39010.2.4 Hardening and Crosslinking of Tannins 40010.2.5 Hardening of Tannins by Hexamethylenetetramine (Hexamine) 41810.2.6 Autocondensation of Tannins 41910.2.7 Combination of Tannins with Natural Components 42110.2.8 Combination of Tannins with Synthetic Components and Crosslinkers 42110.3 Lignin-Based Adhesives 42110.3.1 Chemistry and Structure of Lignin 43010.3.2 Lignin as Adhesive 43210.3.3 Analysis of Molecular Structure 43710.3.4 Modification of Lignin 43710.3.5 Lignin as Sole Adhesive and Chemical Activation of the Wood Surface 45210.3.6 Laccase Induced Activation of Lignin 45210.3.7 Pre-Methylolation of Lignin 46910.3.8 Incorporation of Lignin into PF Resins 48110.3.9 Reactions of Lignin With Various Aldehydes and Other Naturally-Based Components 48110.3.10 Reaction of Lignin With Synthetic Components and Crosslinkers 48110.4 Summary 481General Literature (Overview and Review Articles) for Tannin and Lignin 499References 50111 Adhesion in Biocomposites: A Critical Review 531Siji K. Mary, Merin Sara Thomas, Rekha Rose Koshy, Prasanth K.S. Pillai, Laly A. Pothan and SabuThomas11.1 Introduction 53111.2 Biocomposite Processing Methods 53311.3 Factors Enhancing Adhesion Property in Biocomposites 53611.3.1 Effect of Chemical Modification 53711.3.2 Effect of Enzymatic Modification 53911.3.3 Effect of Physical Modification 53911.4 Physical and Chemical Characterization 54211.5 Adhesion in Polymer Biocomposites with Specific Applications 54511.5.1 Biomedical Applications 54611.5.2 Dye Adsorption and Removal 54711.5.3 Automotive Applications 54811.6 Summary 549References 54912 Vacuum UV Surface Photo-Oxidation of Polymeric and Other Materials for Improving Adhesion: A Critical Review 559Gerald A. Takacs, Massoud J. Miri and Timothy Kovach12.1 Introduction 55912.2 Vacuum UV Photo-Oxidation Process 56112.2.1 VUV Background 56112.2.2 VUV Radiation 56112.2.2.1 Emission from Excited Atoms 56112.2.2.2 Emission from High Pressure Rare Gas Plasmas 56312.2.2.3 Emission from Rare-Gas Halides and Halogen Dimers 56412.2.3 VUV Optical Filters 56412.2.4 Penetration Depths of VUV Radiation in Polymers 56512.2.5 Analytical Methods for Surface Analysis 56512.2.6 VUV Photochemistry of Oxygen 56512.2.7 Reaction of O Atoms and Ozone with a Polymer Surface 56612.3 Adhesion to VUV Surface Photo-Oxidized Polymers 56712.3.1 Fluoropolymers 56712.3.2 Nafion® 56812.3.3 Polyimides 56912.3.4 Metal-Containing Polymers 56912.3.5 Polyethylene (PE) 57012.3.6 Polystyrene 57112.3.7 Other Polymers 57112.3.7.1 Polypropylene (PP) 57112.3.7.2 Poly(ethylene terephthalate) (PET) 57112.3.7.3 Poly(ethylene 2,6-naphthalate) (PEN) 57112.3.7.4 Cyclo-Olefin Polymers 57212.3.7.5 Polybenzimidazole (PBI) 57212.4 Applications of VUV Surface Photo-Oxidation to Other Materials 57312.4.1 Carbon Nanotubes and Diamond 57312.4.2 Metal Oxides 57412.5 Prospects 57512.5.1 Sustainable Polymers 57512.6 Summary 576References 57613 Bio- and Water-Based Reversible Covalent Bonds Containing Polymers (Vitrimers) and Their Relevance to Adhesives – A Critical Review 587Natanel Jarach, Racheli Zuckerman, Naum Naveh, Hanna Dodiuk and Samuel KenigList of Abbreviations 58713.1 Introduction 58813.1.1 RCBPs Classification 58913.1.2 Reversible Bonds 59013.1.2.1 General Reversible Covalent Bonds 59013.1.2.2 Dynamic Reversible Covalent Bonds 59013.1.3 RCBPs Applications 59113.1.3.1 Recyclability 59113.1.3.2 Self-Healing Materials 59213.1.3.3 Shape-Memory Materials 59213.1.3.4 Smart Composites 59313.1.3.5 Adhesives 59313.1.3.6 Dynamic Hydrogels and Biomedical Materials 59413.2 Bio-Based RCBPs 59513.2.1 Bio-Based Polymers 59513.2.1.1 Classification of Bio-Based Polymers 59613.2.1.2 Common Synthetic Bio-Based Polymers 59613.2.2 Bio-Based RCBPs 59913.2.2.1 Bio-Based DA RCBPs 60013.2.2.2 Bio-Based Acylhydrazone-Containing RCBPs 60113.2.2.3 Bio-Based Imine (Schiff-Base)-Containing RCBPs 60113.2.2.4 Bio-Based β-Hydroxy Ester Containing RCBPs 60413.2.2.5 Bio-Based Disulfide-Containing RCBPs 60613.3 Water-Based RCBPs 60713.3.1 Solvents in Polymer Industry 60713.3.1.1 Organic and Inorganic Solvents Used in RCBPs Synthesis 60813.3.1.2 Water-Based Polymers 60813.3.2 Water-Based RCBPs 60913.3.2.1 Acylhydrazone-Containing Water-Based RCBPs 60913.3.2.2 Schiff-Base-Containing Water-Based RCBPs 60913.4 Summary 61113.5 Authors Contributions 61113.6 Funding 61113.7 Conflict of Interest 611References 61214 Superhydrophobic Surfaces by Microtexturing: A Critical Review 621Anustup Chakraborty, Alan T. Mulroney and Mool C. Gupta14.1 Introduction 62214.1.1 Background 62214.1.2 State-of-the-Art 62614.1.2.1 Microtexture Geometry 62714.1.2.2 Ice Adhesion 62714.1.2.3 Optical Transparency 62814.1.2.4 Anti-Condensation Surfaces 62814.2 Fabrication of Microtextured Surfaces 62814.2.1 Surface Materials 62814.2.2 Methods of Fabrication of Superhydrophobic Surfaces 63014.2.2.1 Plasma Treatment 63014.2.2.2 Laser Ablation 63114.2.2.3 Chemical Etching 63214.3 Properties of Microtextured Surfaces 63414.3.1 Antifogging 63414.3.2 Antibacterial 63414.3.3 Antireflection 63414.3.4 Self-Cleaning 63614.3.5 Effect of Temperature on Surface Properties 63614.4 Applications 63914.4.1 Anti-Icing 63914.4.2 Drag Reduction 64014.4.3 Anti-Corrosion 64114.4.4 Solar Cells 64114.4.5 Water-Repellent Textiles 64114.5 Future Outlook 643Acknowledgments 644References 64415 Structural Acrylic Adhesives: A Critical Review 651D.A. Aronovich and L.B. Boinovich15.1 Introduction 65115.2 Compositions and Chemistries 65315.2.1 Base Monomer 65415.2.2 Thickeners and Elastomeric Components 65615.2.3 Adhesive Additives 66315.2.4 Initiators 66515.2.5 Aerobically Curable Systems 67015.2.6 Fillers 67115.3 Physico-Mechanical Properties of SAAs 67315.4 Adhesives for Low Surface Energy Materials 67715.4.1 Initiators Based on Trialkylboranes 67715.4.2 Alternative Types of Boron-Containing Initiators 68615.4.3 Additives Modifying the Curing Stage 68715.4.4 Hybrid SAAs 69015.5 Comparison of the Properties of SAAs and Other Reactive Adhesives 69315.6 Summary and Outlook 698References 69816 Current Progress in Mechanically Durable Water-Repellent Surfaces: A Critical Review 709Philip Brown and Prantik Mazumder16.1 Introduction 70916.2 Fundamentals of Superhydrophobicity and SLIPs 71016.2.1 Intermolecular Forces and Wetting 71016.2.2 Young’s Contact Angle and Surface Chemistry Limitation 71216.2.3 Superhydrophobicity by Texturing 71516.2.4 Hysteresis and Tilt Angle 71716.2.5 Slippery Liquid-Infused Porous Surfaces (SLIPs) 71916.3 Techniques to Achieve Water-Repellent Surfaces 72016.3.1 Superhydrophobic Composite Coatings 72016.3.2 Superhydrophobic Textured Surfaces 72416.3.3 Liquid-Impregnated Surfaces/SLIPs 72816.4 Durability Testing 72916.5 Future Trends 73216.6 Summary 734References 73417 Mussel-Inspired Underwater Adhesives- from Adhesion Mechanisms to Engineering Applications: A Critical Review 739Yanfei Ma, Bozhen Zhang, Imri Frenkel, Zhizhi Zhang, Xiaowei Pei, Feng Zhou and Ximin He17.1 Introduction 74017.2 Adhesion Mechanisms of Mussel and the Catechol Chemistry 74117.2.1 Hydrogen Bonding and Metal Coordination 74217.2.2 Hydrophobic Interaction 74317.2.3 Cation/Anion/π-π Interactions 74317.2.4 The Flexibility of the Molecular Chain 74417.3 Catechol-Functionalized Adhesive Materials 74417.3.1 Permanent/High-Strength Adhesives 74517.3.2 Temporary/Smart Adhesives 74817.3.2.1 pH-Responsive Adhesives 74817.3.2.2 Electrically Responsive Adhesives 75017.3.2.3 Thermally Responsive Adhesives 75017.3.2.4 Photo-Responsive Adhesives 75017.3.3 Applications 75117.4 Summary and Outlook 753References 75418 Wood Adhesives Based on Natural Resources: A Critical Review Part IV. Special Topics 761Manfred DunkyList of Abbreviations 76218.1 Liquified Wood 76518.2 Pyrolysis of Wood 76918.3 Replacement of Formaldehyde in Resins 77218.4 Unsaturated Oil Adhesives 79118.5 Natural Polymers 79318.5.1 Poly(lactic acid) (PLA) 79318.5.2 Natural Rubber 79518.6 Poly(hydroxyalkanoate)s (PHAs) 79618.7 Thermoplastic Adhesives Based on Natural Resources 79718.7.1 Polyurethanes (PURs) 79818.7.2 Polyamides (PAs) 80618.7.3 Epoxies 80818.8 Cellulose Nanocrystals (CNCs) and Cellulose Nanofibrils (CNFs) 80818.8.1 Cellulose Nanofibrils (CNFs) as Sole Adhesives 81018.8.2 Cellulose Nanofibrils as Components of Adhesives 81218.9 Cashew Nut Shell Liquid (CNSL) 81218.10 Summary 819General Literature (Overview and Review Articles) for Wood Adhesives Based on Natural Resources 820References 82019 Cold Atmospheric Pressure Plasma Technology for Modifying Polymers to Enhance Adhesion: A Critical Review 841Hom Bahadur Baniya, Rajesh Prakash Guragain and Deepak Prasad Subedi19.1 Introduction 84219.2 Atmospheric Pressure Plasma Discharge 84419.2.1 Corona Discharge 84419.2.2 Dielectric Barrier Discharge (DBD) 84519.2.3 Cold Atmospheric Pressure Plasma Jet (CAPPJ) 84519.2.4 Polymer Surface Modification by CAPPJ 84519.3 Experimental Setup for the Generation of Cold Atmospheric Pressure Plasma Jet 84619.4 Methods and Materials for Surface Modification of Polymers 84719.5 Direct Method for the Determination of Temperature of Cold Atmospheric Pressure Plasma Jet (CAPPJ) 84819.6 Results and Discussion 84819.6.1 Temperature Determination of Cold Atmospheric Pressure Plasma Jet (CAPPJ) 84819.6.2 Electrical Characterization of the CAPPJ 84919.6.2.1 Power Balance Method 84919.6.2.2 Current Density Method 85019.6.2.3 Determination of Energy Dissipation in the Cold Plasma Discharge per Cycle by the Lissajous Figure Method 85119.6.3 Optical Characterization of CAPPJ 85219.6.3.1 Line Intensity Ratio Method 85219.6.3.2 Stark Broadening Method 85619.6.3.3 Boltzmann Plot Method 85819.6.3.4 Determination of the Rotational Temperature 85919.6.3.5 Determination of the Vibrational Temperature 86019.7 Surface Characterization/Adhesion Property of Polymers 86219.7.1 Contact Angle Measurements and Surface Free Energy Determination 86219.7.1.1 Poly (ethylene terephthalate) (PET) 86219.7.1.2 Polypropylene (PP) 86419.7.1.3 Polyamide (PA) 86719.7.1.4 Polycarbonate (PC) 86919.7.2 FTIR Analysis 87119.7.2.1 Fourier Transform Infrared (FTIR) Analysis of PET 87119.7.2.2 Fourier Transform Infrared (FTIR) Analysis of PP 87219.7.3 SEM Analysis 87219.7.3.1 SEM Images of the Control and APPJ Treated PET 87219.7.3.2 SEM Images of the Control and APPJ Treated PP 87219.8 Summary 873Acknowledgements 874Data Availability 874Conflict of Interest 874References 874