Textile Chemistry, 2nd Edition
By Thomas Bechtold and Tung Pham
Contents:
Preface of second edition XIII
1 Textiles 1
1.1 Introduction 1
1.2 Spinning 1
1.3 Linear density – yarn count 3
1.4 Fabric formation 4
1.5 Textile chemical aspects in spinning and fabric formation 5
1.5.1 Spin finish 6
1.5.2 Sizing 8
1.5.3 Embroidery 10
1.5.4 Printing/coating 10
1.5.5 Garment production/assembly/joining 11
1.5.6 Technical textiles 11
References 12
2 Textile fibres 17
2.1 Fibre production 17
2.2 Fibre formation 20
2.2.1 Polymer-dependent fibre properties 20
2.3 Molecular mass/degree of polymerisation 24
2.4 Important fibres and their chemistry 26
2.4.1 Cellulose fibres 26
2.4.2 Structure of cotton/flax/hemp fibres 27
2.5 Relevant aspects of cellulose chemistry (chemical reactions,
derivatisation and chemical stability) 32
2.6 Chemical reactions 35
2.6.1 Derivatisation 35
2.6.2 Hydrolysis 35
2.6.3 Oxidation 36
2.6.4 Esterification 37
2.6.5 Etherification 38
2.6.6 Complex formation 39
2.6.7 The secondary structure of cellulose 40
2.6.8 Methods of structural characterisation 41
2.7 Regenerated cellulose fibres 42
2.7.1 Dissolution of cellulose 42
2.7.2 The viscose process 43
2.7.3 Lyocell fibres – the NMMO process 46
2.7.4 Ionic liquids and other cellulose solvents 49
2.7.5 Cupro fibres – the cuprammonium process 49
2.7.6 Cellulose diacetate and triacetate 50
2.8 Protein fibres 51
2.8.1 General aspects of protein fibres 51
2.8.2 Protein structure – basic properties 52
2.8.3 Wool 55
2.8.4 Silk 57
2.8.5 Casein fibres 58
2.9 Synthetic fibres 59
2.9.1 General 59
2.9.2 Polyamide 60
2.9.3 Aminocarboxylic acid-based PAs 61
2.9.4 Diamine–dicarboxylic acid-based PAs 63
2.9.5 PES fibres 65
2.9.6 Polylactic acid and polyhydroxybutyrate 69
2.9.7 Polyurethanes/elastomer fibres 71
2.9.8 Polyolefin fibres, PE and PP 74
2.9.9 Polyacrylonitrile fibres 78
2.9.10 High-performance fibres 80
References 83
3 Structure of textile fibres 91
3.1 General aspects 91
3.2 Crystallinity versus amorphous regions 91
3.3 Constitution of a polymer 92
3.4 High-performance fibres 94
3.5 Molecular weight distribution 95
3.6 Consequences of polydispersity 96
3.7 Configuration 97
3.8 Conformation 100
3.8.1 Conformational statistics 101
3.9 Polymer assemblies 101
3.10 The thermodynamic non-equilibrium state of polymers 103
3.11 Models of fibre structure 104
3.12 Consequences of polymer order in a fibre 107
3.12.1 Moisture/adsorption/swelling 108
References 110
4 Basic interactions between fibre polymers and sorptives 113
4.1 General 113
4.2 Dipoles 113
4.3 Polarisability 115
4.4 Molecular interactions 117
4.4.1 Ion–ion interactions 117
4.4.2 Van der Waals forces 119
4.4.3 Hydrogen bonds 120
4.4.4 Hydrophobic interactions 121
4.4.5 π-electron interactions 122
4.5 The polymer–solvent boundary layer 123
4.6 Zeta potential 126
4.7 Donnan equilibrium 131
References 133
5 Thermodynamics and kinetics in fibre chemistry 137
5.1 Moisture sorption 137
5.2 Moisture sorption isotherms 138
5.2.1 Water activity 139
5.3 Sorption kinetics for adsorption from the gas phase 144
5.4 Sorption from the liquid phase 148
5.4.1 General considerations 148
5.4.2 The Nernst isotherm 149
5.4.3 The Freundlich isotherm 150
5.4.4 Langmuir adsorption isotherm 152
5.4.5 Special aspects of sorption isotherms 154
References 160
6 Kinetics of textile chemical processes 165
6.1 Elementary steps in polyester dyeing 165
6.2 Step A – dissolution of dispersed dye 165
6.3 Infinite and finite dyeing kinetics 167
6.4 Step B – hydraulic transport in the dyebath 168
6.5 Step C – diffusion through the boundary layer of the fibre 169
6.6 Step D – dyestuff sorption in the fibre 170
6.7 Levelling 171
6.8 Follow-up reactions – kinetics in reactive dyeing 172
6.9 Preceding and following reactions – vat dyeing 174
6.10 Aggregation 175
References 176
7 Basics of colour development 179
7.1 The phenomenon of colour – how to approach? 179
7.2 Physical aspects of colour development 179
7.3 Additive and subtractive colour 183
7.4 Development of colour 184
7.5 Colour variations independent of molecular structure 190
7.6 Fluorescence and phosphorescence 191
7.7 Textile chemical relevance 193
References 196
8 General principles of dyes 201
8.1 The molecular structure of dyes 201
8.2 The azo chromophore 201
8.2.1 Mono-, di- and polyazo dyes 201
8.2.2 The diazotisation 202
8.2.3 The coupling component 204
8.3 Anthraquinone chromophores 207
8.4 Indigoid chromophores 210
8.5 Cationic dyes 210
8.6 Polymethine dyes 211
8.7 Phthalocyanine dyes – Aza[18]annulenes 212
8.8 Sulphur-based chromophores 213
8.9 Metal complexes 214
8.10 Formazan dyes 215
8.11 Fluorescent brighteners/fluorescent whitening agents 216
8.12 Photodegradation of dyes 216
8.13 Photodegradation of dye classes 218
References 222
9 Colour measurement 225
9.1 The perception of colour 225
9.2 The standard observer 228
9.3 Colour specification through the CIELAB system 230
9.4 Metamerism 231
9.5 Tristimulus values 232
9.6 Colour coordinates 234
9.7 Measurement of reflectance curves 238
9.8 Determination of whiteness, yellowness 240
9.9 Colour strength – the Kubelka–Munk function 241
9.10 Prediction of dyeing recipes 244
9.11 Gloss/lustre 245
References 246
10 Dye chemistry 249
10.1 Overview 249
10.2 Disperse dyes 249
10.2.1 Dyeing processes with disperse dyes 249
10.2.2 Reductive cleaning 253
10.3 Direct dyes 254
10.4 Reactive dyes 256
10.4.1 Chemistry of reactive dyes 256
10.4.2 Important dyeing techniques 264
10.5 Vat dyes 268
10.5.1 Oxidation/soaping 274
10.6 Indigo 278
10.6.1 Synthesis of indigo 278
10.6.2 Application of indigo 279
10.6.3 Chemistry of indigo reduction 282
10.6.4 Garment wash – fading 286
10.7 Sulphur dyes 287
10.8 Acid dyes and metal complex dyes 291
10.9 Naphthol dyes 294
10.10 Cationic dyes/basic dyes 295
10.11 Natural colourants 297
10.11.1 General aspects 297
10.11.2 Major classes of natural colourants 298
10.11.3 Tannin-based dyes 305
10.12 Pigment dyes 307
10.13 Textile printing 308
10.13.1 General aspects of printing 308
10.13.2 Screen printing 312
10.13.3 Ink-jet printing 313
10.13.4 Special printing techniques 315
References 316
11 Pre-treatment 323
11.1 Sizing 323
11.2 Desizing 326
11.3 Alkaline extraction 327
11.4 Prewashing of textiles from synthetic fibres 328
11.5 Setting of synthetic fibres 328
11.6 Alkalisation (causticising, mercerisation) 329
11.7 Alkalisation of polyester fibres 331
11.8 Bleaching 332
11.8.1 General aspects 332
11.8.2 Peroxide compounds 332
11.8.3 Halogen-based oxidants 335
11.9 Singing 337
11.10 Carbonisation 337
11.11 Reductive bleach 338
11.12 Wool anti-felt treatment 339
11.13 Cationisation 341
11.14 Degumming of silk 341
11.15 Production of microfibres 342
References 342
12 Finishing 347
12.1 General aspects 347
12.2 Easy-care/durable press finishing 347
12.3 Softening 351
12.4 Hand building finishes 353
12.5 Water-repellent finishes 354
12.6 Flame retardant finishes 356
12.7 Antistatic finishes 361
12.8 Improvement of colour fastness 366
12.9 Improving the light fastness 367
12.10 UV protection 368
12.11 Antimicrobial finishing 371
12.12 Insect-resistant finishes – Mite protection 374
12.13 Enzymatic finishing – biofinishing 375
12.14 Denim finishing 376
12.15 Finishes that influence thermal regulation 379
12.16 Sorption of fragrances and functional substances 380
12.17 Plasma chemistry in textile treatment/modification 381
12.17.1 Introduction 381
12.17.2 Effect of plasma treatment on fibre and textile surfaces 382
12.17.3 Free radical formation 383
12.17.4 Etching/cleaning 383
12.17.5 Surface activation and functionalisation 384
12.17.6 Surface coating by plasma-induced polymerisation 384
12.17.7 Industrial plasma technologies and applications on textiles 385
References 386
13 Technical approaches in dyestuff/chemical application 391
13.1 General aspects 391
13.2 Batchwise operation 392
13.3 Yarn dyeing apparatus 392
13.4 Overflow dyeing machines/jet dyeing machines 394
13.5 Continuous pretreatment 395
13.6 Continuous dyeing processes – cold-pad-batch dyeing 400
13.7 Continuous dyeing processes – pad-dry/pad steam plants 402
13.8 Drying, fixation and finishing 406
13.9 Minimum pick-up applications 407
13.10 Coating and laminating 408
References 409
14 Surfactants, detergents and laundry 415
14.1 Surfactants 415
14.2 Classification of surfactants 415
14.3 Solubility of surfactants 416
14.4 Contact angle 418
14.5 Cloud point 421
14.6 Surfactant adhesion at interfaces 421
14.7 The role of multivalent ions 423
14.8 Detergent ingredients 423
14.9 Washing and environment 430
References 430
15 Environmental aspects of textiles 433
15.1 Waste water 433
15.2 General wastewater treatment 434
15.3 Processing steps and relevant aspects of wastewater treatment 435
15.3.1 General 435
15.3.2 Wool processing 436
15.3.3 Sizing/desizing 436
15.3.4 Scouring, bleaching, pre-washing 438
15.3.5 Mercerisation/causticising 439
15.3.6 Dyeing processes 440
15.3.7 Printing 442
15.3.8 Finishing 442
15.4 End-of-pipe technologies 443
15.4.1 Neutralisation 443
15.4.2 Filtration techniques 443
15.4.3 Flocculation and sedimentation 444
15.4.4 Oxidative processes 445
15.4.5 Adsorption 445
15.4.6 Biological (aerobic, anaerobic) treatment 445
15.5 Recycling and disposal 446
15.6 Approaches and challenges 447
References 447
16 Circularity, recycling and disposal 453
16.1 The EU concept of circularity 453
16.2 Terms and definitions used for assessment of products and
processes 455
16.3 Important steps in a circular concept 456
16.4 Composition of textile material 456
16.5 Design for recycling 457
16.6 Facilitating steps 457
16.7 Mechanical recycling 458
16.8 Thermal recycling 460
16.9 Chemical recycling 464
16.10 Consumer use 469
References 470
Index 473