Applied Coatings: Chemistry, Formulation, and Performance

APPLIED COATINGS An integrated collection of case studies providing a concise guide for professionals working with coatings materials in academia and industry In Applied Coatings: Chemistry, Formulation, and Performance, distinguished scientist Dr. Weih Q. Lee delivers an illuminating collection of case studies designed to connect various elements of applied coatings technology. Going beyond generic discussions, the author describes the fundamental chemistry, formulations, and properties of applied coating materials – including the structural and functional components of structure-property relationships – as well as the foundations of applied cure kinetics and the rheology of epoxy coatings. Each chapter is self-contained, comprehensive, and can be read individually, while the book remains technically and editorially integrated. Core themes include structure-performance relationships, formulation index driven experiment design, and consolidated thermal analysis. Readers will also find: A thorough introduction to epoxies and epoxy curing agents, including oxetanes, vinyl esters, glycidyl methacrylate (GMA), isocyanate and silicone crosslinkers, cationic catalysts, acrylate and phenol accelerators, and specialty derivatives Attentive descriptions of epoxy curing chemistry, including epoxy-phenolic, -polyamide, -active ester, and acid- or base-catalyzed systems in a broader scope Comprehensive explorations of cure kinetics and rheology, including model-free kinetics (MFK), the nth-order model covering Kissinger plots and the Borchardt—Daniels (BD) approach, the autocatalytic model, executive quantification via curve fitting of DSC (differential scanning calorimetry) exotherms, the rheology of non-reactive fluids, and the viscoelasticity of reactive coatings Practical discussions of C1S thick-film surface coatings, C2S structural lamination, liquid and powder epoxies, and phenolic coatings, including fluorene monomers, heterocyclic resins, and polymerizable derivatives Complete treatments of coating characterization, microencapsulation, epoxy hybrids and non-epoxy platforms, adhesion of applied coatings, and adhesion promotion, including reactive and functional silicones Perfect for formulation and research and development scientists and engineers at any technical level, Applied Coatings will also benefit research professors and students studying coatings, adhesives, composites, electronic materials, and more.

Table of Contents:
Preface xi Abbreviations, Symbols, and Units xiii Introduction xxix Part I Materials and Chemistry 1 1 Epoxy Resins, Monomers, and Derivatives 3 1.1 BPA-Based Epoxies (or DGEBAs) 3 1.2 BPF-Based (or DGEBF) and Novolac Epoxies 5 1.3 Modified Epoxies 7 1.4 Poly-functional or Matrix Epoxies 10 1.5 Specialty Epoxies 12 1.6 Aliphatic and UV-Curable Epoxies 14 1.7 Oxetanes 15 1.8 Epoxy Derivatives 16 1.9 BPA-Free Epoxies 17 1.10 Bio-Based Epoxies 18 1.11 Epoxy Diluents and Flexibilizers 19 1.12 Epoxy Vitrimers 19 Debrief A Hydrophobicity 20 Debrief B MWs, EEWs, and functionality (f) 20 Debrief C Synthesis of SERs from LERs 21 Debrief D Oxazolidinones, oxazolidones, oxazolidines, bisoxazolidines, and bis-oxazolines 22 Recaps and Highlights 23 References 25 2 Epoxy Curing Agents 29 2.1 Crosslinkers or Hardeners 29 2.1.1 Primary and secondary amines 29 2.1.2 Phenolics and polyphenols 36 2.1.3 Active esters 41 2.1.4 Mannich bases 42 2.1.5 Anhydrides and carboxylic acids 42 2.1.6 Polysulfides or mercaptans 44 2.1.7 Isocyanates 45 2.1.8 Silicones 47 2.2 Catalysts and Accelerators 48 2.2.1 Catalysts 48 2.2.1.1 Anionic catalysts: tertiary (3∘) amines and imidazoles 48 2.2.1.2 Cationic catalysts 50 2.2.2 Accelerators and modifiers 52 2.2.2.1 Phenol derivatives 52 2.2.2.2 Acrylates 53 2.3 UV Radiation 53 Debrief A Amine and anhydride crosslinkers 54 Debrief B Aromaticity vs. aliphaticity, and hydrophilicity vs. hydrophobicity 54 Debrief C Reactivity and effectiveness of catalysts 56 Recaps and Highlights 57 References 58 3 Epoxy Curing Reactions 63 3.1 Co- and Homo-Polymerizations 63 3.1.1 Epoxy-amine (and -hydrazide) systems 64 3.1.2 Epoxy-phenolic systems 66 3.1.3 Epoxy-ester systems 67 3.1.4 Epoxy-anhydride systems 69 3.2 Cationic and UV-Curing Systems 70 Debrief A Base-catalyzed crosslinking reactions 73 Debrief B Acid-catalyzed crosslinking reactions 75 Debrief C Carbene insertion reactions 77 Debrief D Additional understanding of ring-opening reactions 78 Recaps and Highlights 79 References 81 Part II Methodologies and Characterization 85 4 Concepts, Utilities, Methods, and Techniques 87 4.1 Liquids versus Powders 87 4.1.1 Solvent-based coatings 88 4.1.2 Waterborne (WB) coatings 91 4.1.3 Electro-coatings (E-coatings) 93 4.1.4 Powder coatings 94 4.1.5 UV-curable coatings 95 Debrief A Liquid applications and end uses 95 Debrief B Powder applications and end uses 101 4.2 The Formulation Index 102 4.3 Surface Coatings versus Structural Laminates 103 Debrief C Surface coatings and end uses 105 Debrief D Structural laminates and end uses 107 4.4 Materials and System Properties of Cured Coatings 108 4.5 Characterization of Uncured Coatings 116 Debrief E Illustrations of applied coating technology 120 Debrief F Reverse engineering 122 Recaps and Highlights 125 Appendices 127 A Hydrogen Energy 127 B Power Module 128 C LED Module (Tj ∼120∘ C) 128 References 129 5 Cure Kinetics and Rheology 135 5.1 Cure Kinetics 135 5.1.1 Gel time model 136 5.1.2 Tg model 137 5.1.3 Model-free kinetics 137 5.1.4 nth-order model 139 5.1.4.1 The Kissinger plot 140 5.1.4.2 Borchardt−Daniels (BD) approach 142 5.1.5 Autocatalytic model 143 5.1.6 Comparisons of model-based kinetics 146 Debrief A Thermal and kinetic parameters and their correlations 148 5.1.7 Application of cure kinetics to processing 152 5.1.8 Implementation of cure kinetics in formulation 154 5.1.8.1 Resins 154 5.1.8.2 Crosslinkers 155 5.1.8.3 Catalysts 156 5.1.8.4 Reactive additives 158 5.1.9 Implementation of cure kinetics in 2K liquid epoxy coatings 160 Debrief B Supplemental cure kinetic equations 161 Debrief C Evaluation of latent catalysts by DSC kinetics 161 Recaps and Highlights (I) 164 5.2 Rheology 165 5.2.1 Rheology of non-reactive fluids 166 Debrief D Major rheological phenomena 176 Debrief E Common rheological materials and their characterization 177 5.2.2 Rheology of reactive systems 179 Debrief F Rheological DMA 184 Recaps and Highlights (II) 185 5.3 Kinetics and Rheology Combined 187 Debrief G DMA-DSC consolidation 191 Recaps and Highlights (III) 193 Acknowledgments 194 References 194 Part III Formulations and Applications 199 6 Formulation Case Studies 201 6.1 Liquid Epoxy Coatings and Adhesives 201 6.1.1 One-component (1K) SB epoxy coatings for laminating 201 6.1.2 Two-component (2K) epoxy coatings for surface lining 203 6.1.3 2K epoxy adhesives as thermal interface materials 205 6.2 Functional Epoxy Powder Coatings 206 6.2.1 Formulation index-oriented formulation optimization 206 6.2.2 Crosslinker-free formulations 210 6.2.3 Bisphenol F-based epoxy resins 218 6.2.4 Aliphatic epoxies and silicone-modified amines 222 6.2.5 Active ester crosslinkers 226 6.2.6 Phenylene bis-oxazoline crosslinkers 230 6.2.7 Fluorene monomers for heat-resistant coatings 233 6.2.8 Cationic catalysts and dual cure 242 6.2.9 Specialty and miscellaneous materials and formulations 251 Debrief A Extremely flexible FBE coatings through SDH and BAF amines 253 Debrief B LAT coatings 256 Debrief C Primers, epoxy primers, and epoxy powder primers 267 Debrief D Illustration of first-order reaction (n ≈ 1.0 and m = 0) epoxy formulations 269 Recaps and Highlights 270 Appendices 274 A Comparative Study on Anionic DMS and Cationic BCl3 Amine Complex 274 B Images of Free-Radical Powder Coating-Coated MDF Panels 275 References 276 7 Phenolic Coatings 279 7.1 Phenolic Resins and Derivatives 279 7.1.1 BPA-based phenolic resins 279 7.1.2 Novolac and resole phenolic resins 281 7.1.3 Non-BPA phenolic resins and bio-derivatives 282 7.2 Phenolic-Isocyanate Coatings 287 7.3 Phenolic-BMI Systems 292 7.4 BOXs and BOX-Isocyanate Coatings 295 7.5 BOX-BMI Systems 298 7.6 Quantification of Ph-OHs by UV/Visible 303 Debrief A BMIs and Diels−Alder ring-forming reactions 314 Debrief B UV/visible technique 315 Recaps and Highlights 316 Acknowledgments 317 References 317 Part IV Extended Formulations and Applications 323 8 Microencapsulation 325 8.1 Morphology 325 8.2 Physical Encapsulation 327 8.3 Chemical Encapsulation 329 8.3.1 Core/shell microcapsules via in-situ polymerization 331 8.3.2 Core/shell microcapsules via interfacial polymerization 333 8.4 DOE Example of Microcapsule Formulation and Processing Optimization 335 Debrief A Melamine and amino derivative crosslinkers 340 Debrief B Urea-glyoxal resins and derivatives 344 Debrief C Michael Addition reactions and applications 344 Debrief D Microencapsulation via interfacial polymerization 346 Recaps and Highlights 349 Appendix 350 A Exemplary Carbonless Paper Coatings 350 References 351 9 Hybrids and Non-Epoxy Platforms 355 9.1 Epoxy Hybrids 355 9.1.1 Epoxy-isocyanate systems 355 9.1.2 Epoxy-urethane/urea systems 357 9.1.3 Epoxy-acrylate/BMI systems 357 9.2 Non-Epoxy Systems 364 9.2.1 Polyurethanes and polyols 364 9.2.2 Acrylics and acrylates 367 9.2.3 Polyesters and their monomers 370 9.2.4 Acrylate adhesive case studies 372 9.2.5 Polyurea coating case studies 374 9.2.6 Silicones: silanes, TEOS, PDMS, elastomers 377 9.3 Non-Epoxy Hybrids 389 9.3.1 Phthalonitrile (PN) and BOX-PN hybrids 390 9.3.2 Miscellaneous high-performance polymers 393 Debrief A Silanes, silicates, and PDMSs 394 Debrief B Non-epoxy polymers and hybrids 396 Debrief C Dual UV/thermal curing silicones 399 Recaps and Highlights 400 References 402 Part V Adhesiveness and Adhesion 409 10 Adhesion and Adhesion Promotion 411 10.1 Bulk Adhesives 411 10.1.1 Epoxy structural adhesives 412 10.1.2 Acrylic and PUR structural adhesives 413 10.1.3 One-component (1K) moisture curable PUR and silicone adhesives 415 10.1.4 Anaerobic and instant adhesives 417 10.1.5 Titanate catalysts and formulation tips 419 10.2 Characterization of Adhesives and Adhesion 420 10.2.1 Reactive adhesives 420 10.2.2 Non-reactive adhesives 421 10.2.3 HM adhesives as TIMs: a case study 422 10.3 Substrates and Interfaces 423 10.3.1 Surface energy and surface tension 424 10.3.2 Surface modifications 427 10.3.3 Monomeric and polymeric silanes 428 10.3.4 Other adhesion promoters and adhesive polymers 432 10.4 Adhesion Troubleshooting 437 Debrief A Industrial rheology of adhesives and sealants 438 Debrief B Reactive adhesives 441 Debrief C Organo-functional silanes 442 Debrief D Anticorrosion of coatings on ferrous metals 443 Debrief E Polythiol reactions 446 Recaps and Highlights 447 References 451 11 Closing Remarks 459 Wrap-Ups 459 Outlooks 468 Green and circular 470 Hybrid and smart 471 References 474 Index 479

About the Author :
Weih Q. Lee, PhD, has over 20 years’ experience as a formulation scientist in the coatings industry. The author holds advanced degrees in Bioproducts Engineering and Chemistry from the University of Minnesota Twin Cities Campus.