Contents
Society of Dyers and Colourists xi
Preface xiii
1 Fundamental Aspects of Textile Fibres 1
1.1 Textiles 1
1.1.1 Yarn 2
1.1.2 Fabric 4
1.1.3 Textile Markets 6
1.2 Textile Fibres 6
1.2.1 Textile Fibre Classification 7
1.2.2 Textile Usage 9
1.2.3 The History and Development of Textile Fibres 9
1.2.4 Textile Polymers 12
1.2.5 Textile Fibre Morphology and Fine Structure 16
1.3 General Physical and Mechanical Characteristics of Textile Fibres 27
1.3.1 Length 27
1.3.2 Fineness 27
1.3.3 Twist 32
1.3.4 Fibre Specific Surface Area, Sm or Sv 33
1.3.5 Cross-Sectional Shape 33
1.4 Properties of Textile Fibres 35
1.4.1 Mechanical Properties 35
1.4.2 Thermal Properties 37
1.4.3 Optical Properties 48
References 51
2 Dyes 65
Introduction 65
2.1 Dyes 65
2.1.1 Historical Aspects 66
2.1.2 Classification of Colorants 71
2.1.3 Colour and Constitution 75
2.1.4 Commercial Dye Forms 75
2.1.5 Commercial Dye Names 76
2.1.6 Global Dye Consumption 76
References 76
3 The Role of Water in Aqueous Dyeing 81
Introduction 81
3.1 Water Structure 82
3.2 Water Availability and Global Consumption 84
3.2.1 Water Footprint 85
3.3 Water Use in Dyeing 86
3.3.1 Water Used in Cotton Production 86
3.3.2 Water Used in Fibre Processing 87
3.3.3 Water Used in Dyeing 87
3.4 Water and Textile Fibres 91
3.4.1 Hydrophilicity and Hydrophobicity 93
3.4.2 Moisture Sorption 94
3.4.3 The Porous Nature of Fibres 103
3.4.4 Wetting and Wicking 105
3.4.5 Swelling 109
3.4.6 Water Plasticisation 110
3.5 Water and Dyes 116
3.5.1 Solvation 117
3.5.2 Dye Solubility 120
3.5.3 Dye Aggregation in Solution 123
3.5.4 Dye Aggregation in the Fibre 129
3.5.5 Aqueous Dye Dispersions 129
3.6 pH and pK 134
3.6.1 Water Ionisation (Ionic Product of Water) 134
3.6.2 The pH Scale 135
3.6.3 pKa and pKb 136
3.6.4 Buffer Systems and the Henderson–Hasselbalch Equation 136
References 137
4 Fundamentals of Dyeing 153
Introduction 153
4.1 Dye–Fibre Systems 154
4.2 Fundamental Principles of Dyeing 156
4.2.1 Dye–Fibre Substantivity 156
4.2.2 Driving Force for Dyeing 157
4.2.3 Dye Exhaustion 157
4.2.4 Rate of Dyeing 158
4.2.5 Depth of Shade 159
4.2.6 Liquor Ratio 159
4.2.7 Dye Fixation 160
4.2.8 Wash-Off 161
4.2.9 Fastness 162
4.2.10 Dyeing Auxiliaries 163
References 164
5 Dye–Fibre Interactions 167
Introduction 167
5.1 Intermolecular Interactions (or Forces) between Atoms and Molecules 167
5.1.1 Covalent Bonds 169
5.1.2 Ion–Ion Interactions (aka Charge–Charge, Coulomb, Electrostatic Interactions) 169
5.1.3 Ion–Dipole Interactions (aka Charge–Dipole, Monopole–Dipole) 169
5.1.4 Van der Waals Interactions (aka van der Waals Forces) 170
5.1.5 Hydrogen Bonds 172
5.1.6 Hydrophobic Effect and Hydrophobic Interactions 172
5.1.7 Total (Attractive and Repulsive) Intermolecular Potentials 173
5.1.8 Aromatic Interactions (aka π-Interactions, π-Effects) 173
5.2 Intermolecular Interactions (or Forces) between Macromolecules and Surfaces 176
5.2.1 Dispersion Interactions 176
5.2.2 Electrostatic Forces 178
5.3 Intermolecular Forces in the Context of Textile Fibres and Dyes 190
5.3.1 Intermolecular Forces in Textile Polymers 190
5.3.2 Intermolecular Forces between Dyes and Fibres 191
5.4 Solubility Parameter 192
5.4.1 Hildebrand Solubility Parameter 193
5.4.2 Hansen Solubility Parameters 193
5.4.3 Solubility Parameters and Dye–Fibre Substantivity 194
5.4.4 Carriers 194
5.5 Fibre Modification to Enhance Dye–Fibre Substantivity 195
5.5.1 Mercerisation 195
5.5.2 Plasma 197
5.5.3 Pre-treatment with Cationic Compounds 199
5.5.4 Nucleophilic Dyes on Modified Substrates 200
References 200
6 Dyeing Theory 209
Introduction 209
6.1 Background 210
6.2 Dyeing Systems at Equilibrium (the Thermodynamics of Dyeing) 211
6.2.1 Adsorption 213
6.2.2 Standard Affinity, Standard Heat and Standard Entropy of Dyeing 216
6.3 Kinetics of Dyeing 221
6.3.1 Diffusion 222
6.3.2 Steady-State and Non-Steady-State Diffusion 223
6.3.3 Fick’s Laws of Diffusion 223
6.3.4 Experimental Methods for Determining Diffusion Coefficient 224
6.3.5 Approximate Solutions to Diffusion Equations 228
6.3.6 Characterisation of the Rate of Dyeing 228
6.3.7 Apparent Diffusion Coefficient 229
6.3.8 Boundary Layers in Diffusion 231
6.3.9 Effect of Temperature on Dye Diffusion 233
6.3.10 Influence of Fibre Structure on Diffusion 235
6.3.11 Influence of Dye Structure on Diffusion 237
References 241
7 Cellulosic Fibres 249
Introduction 249
7.1 Cotton 249
7.2 Viscose Fibres 250
7.2.1 Skin–Core Structure 251
7.3 Lyocell Fibres 252
7.4 CA and CTA Fibres 254
7.5 Cellulose Chemistry and Molecular Structure 256
7.5.1 Crystal Forms 257
7.6 Cellulosic Fibre Fine Structure 260
7.7 Hydroxyl Groups in Cellulosic Fibres 261
7.7.1 Accessibility 261
7.8 Water/Cellulose Interactions 263
7.8.1 Moisture Sorption 263
7.8.2 Free and Bound Water 265
7.8.3 Pore Structure 266
7.8.4 Swelling 267
7.8.5 Bleaching of Cotton and Other Cellulosic Fibres 270
7.8.6 Plasticisation 270
7.9 Dye Classes Used on Cellulosic Fibres 272
7.10 The Role of Electrolyte in Cellulosic Fibre Dyeing 273
7.10.1 Nature of the Charged Cellulosic Fibre 274
7.10.2 Zeta Potential of Cellulosic Fibres 274
7.10.3 The Amount of Electrolyte Required to ‘Neutralise’ the Negative Surface Charge 279
7.10.4 Effect of Electrolyte on Dye Aggregation and Dye Solubility 280
7.11 Direct Dyes 281
7.11.1 Classification of Direct Dyes 282
7.11.2 Thermodynamics of Dyeing 283
7.11.3 Kinetics of Dyeing 297
7.11.4 Aftertreatment 301
7.12 Sulphur Dyes 302
7.12.1 Fundamentals of the Chemistry and Application of Sulphur Dyes for Cellulosic Fibres 303
7.12.2 Dye Application 304
7.13 Vat Dyes 305
7.13.1 Fundamentals of the Chemistry and Application of Vat Dyes for Cellulosic Fibres 306
7.13.2 Reduction 308
7.13.3 Adsorption of the Leuco Derivative (Dyeing) 312
7.13.4 Kinetics of Leuco Vat Application 317
7.13.5 Oxidation of the Adsorbed Dye 318
7.13.6 Soaping 319
7.14 Reactive Dyes 319
7.14.1 Fundamentals of the Chemistry and Application of Reactive Dyes for Cellulosic Fibres 320
7.14.2 Mechanism of Dyeing 325
7.14.3 Wash-Off 334
7.14.4 Aftertreatment 337
7.15 Azoic Colorants 337
7.15.1 Naphtholation 338
7.15.2 Development 338
7.15.3 Wash-Off 339
7.16 Disperse Dyes 340
References 340
8 Polyester Fibres 359
Introduction 359
8.1 PES Fibres 359
8.1.1 Fibre Production and Properties 360
8.1.2 Physical Structure 361
8.1.3 Oligomers 363
8.1.4 Sheath/Core Structure 365
8.1.5 Transitions (Relaxations) 365
8.1.6 PES/Water Interactions 366
8.1.7 Dyeing of PES Fibres 367
8.2 PLA Fibres 403
8.2.1 Polymer Synthesis 404
8.2.2 PLA Biodegradability 405
8.2.3 Fibres 405
References 413
9 Polyamide Fibres 427
Introduction 427
9.1 Aliphatic Polyamide Fibres 427
9.1.1 Nomenclature and Types of Polyamides 427
9.1.2 PA 6 and PA 66 429
9.1.3 Physical Structure 430
9.2 Dyeing of Aliphatic Polyamides 445
9.2.1 Effect of Physical Processing on Dyeing 446
9.2.2 Barré Effects 446
9.2.3 Levelling Agents 447
9.3 Acid Dyes 447
9.3.1 Non-metallised Acid Dyes 448
9.3.2 Pre-metallised Acid Dyes (Aka Metal Complex Dyes) 464
9.3.3 Aftertreatment 465
9.4 Disperse Dyes 467
9.5 Mordant Dyes 467
9.6 Direct Dyes 468
9.7 Reactive Dyes 468
9.7.1 Anionic Reactive Dyes 469
9.7.2 Disperse Reactive Dyes 470
9.8 Sulphur Dyes 470
9.9 Vat Dyes 471
9.10 Azoic Colorants 471
9.11 Microfibres 471
9.12 Semi-Aromatic Polyamides 473
9.13 Aromatic Polyamides 474
9.13.1 Fine Structure 475
9.13.2 Water/Aramid Interactions 476
9.13.3 Dyeing of Aromatic Polyamide Fibres 478
References 479
10 Wool Fibres 491
Introduction 491
10.1 Wool Chemistry and Molecular Structure 491
10.1.1 Proteins and Amino Acids 491
10.1.2 Fibre Morphology 494
10.1.3 Fine Structure 496
10.1.4 Water/Wool Interactions 497
10.1.5 Swelling and Heat of Sorption 498
10.1.6 Sorption of Acids and Alkalis 499
10.1.7 Water Plasticisation 499
10.1.8 Effect of Physical and Chemical Properties on Dyeing 500
10.2 Dyes for Wool 500
10.3 Non-metallised Acid Dyes 501
10.3.1 Thermodynamics of Dyeing 501
10.3.2 Effect of Electrolyte on Dye Adsorption 509
10.3.3 Affinities of Acids and Dye Anions 511
10.3.4 Kinetics of Dyeing 513
10.4 Pre-metallised Acid Dyes (Aka Metal Complex Dyes) 516
10.4.1 1 : 1 Metal Complex Dyes 517
10.4.2 1 : 2 Metal Complex Dyes 518
10.5 Mordant Dyes 519
10.5.1 Mechanism of Chroming 520
10.6 Reactive Dyes 521
10.6.1 Historical Aspects 521
10.6.2 Chemistry and Application of Reactive Dyes 521
10.6.3 Levelling Agents 522
References 524
11 Acrylic (polyacrylonitrile) Fibres 531
Introduction 531
11.1 Fibre Production and Properties 531
11.2 Physical Structure 532
11.2.1 Crystallinity or Pseudocrystallinity 533
11.2.2 Transitions (Relaxations) 533
11.2.3 Theories of Fine Structure 533
11.3 PAN/Water Interactions 535
11.3.1 Water Plasticisation 535
11.4 Dyes for PAN Fibres 536
11.5 Basic Dyes 536
11.5.1 Historical Aspects 536
11.5.2 General Characteristics of Basic Dyes 537
11.5.3 Thermodynamics of Dyeing 538
11.5.4 Kinetics of Dyeing 543
11.5.5 Effect of Electrolytes on Dyeing 545
11.5.6 Effect of pH on Dyeing 547
11.5.7 Effect of Temperature on Dyeing 548
11.5.8 Retarding Agents 550
11.5.9 Dyes in Admixture 550
11.5.10 Carriers 551
11.6 Disperse Dyes 551
11.6.1 Thermodynamics of Dyeing 552
11.6.2 Kinetics of Dyeing 552
References 553
12 Silk Fibres 559
12.1 Fibre Morphology 559
12.2 Silk Chemistry and Molecular Structure 559
12.3 Fine Structure 560
12.4 Silk/Water Interactions 564
12.4.1 Water Plasticisation 564
12.5 Dyes for Silk 565
12.5.1 Acid Dyes 566
12.5.2 Reactive Dyes 567
References 568
13 Non-aqueous Dyeing 571
Introduction 571
13.1 Dyeing from Air (Vapour-Phase Dyeing; Thermofixation) 571
13.1.1 General Introduction 571
13.1.2 Thermodynamics of Dyeing 571
13.1.3 Kinetics of Dyeing 573
13.2 Dyeing from Supercritical Carbon Dioxide 575
13.2.1 General Introduction 575
13.2.2 Properties of Supercritical CO2 Fluids 575
13.2.3 Solubility of Dyes in Supercritical CO2 577
13.2.4 Effect of Supercritical CO2 on Fibres 579
13.2.5 Dyeing from Supercritical CO2 582
13.3 Dyeing from Liquid (Non-aqueous) Solvents 592
13.3.1 PER Dyeing 592
13.3.2 Solvent-Assisted Dyeing 594
References 594
Colorants Index 601
Subject Index 605