Properties of hemp fibre polymer composites -An optimisation of ...

Contents
Preface 6
1 Resumé 7
2 List of publications 8
2.1 Published papers 8
2.2 Submitted papers 8
2.3 Posters 8
2.4 Oral presentations 9
2.5 Supplementary publications 9
3 My contribution to the papers 10
4 Introduction 11
4.1 The aim of the thesis 12
4.2 The outline of the thesis 13
5 The hemp plant 14
5.1 Hemp cultivars and growth 14
5.1.1 Cultivation including the experiments at Danish Institute of Agricultural
Sciences 14
5.1.2 Fibre and seed yield 15
5.1.3 Climate in the growth period in 2001 16
5.2 Structure of hemp fibres 18
5.2.1 Structure on the plant stem level (0.002-10 MM) 18
5.2.2 Structure on the fibre bundle level (1-100 μM) 19
5.2.3 Structure on the cell wall level (0.05-20 μM) 20
5.3 Chemical composition of hemp fibres 23
5.3.1 Cellulose and crystallinity 24
5.3.2 Hemicellulose 28
5.3.3 Lignin 29
5.3.4 Pectin 29
6 From hemp plant to composites 30
6.1 From plant stem to fibre assemblies 30
6.1.1 Defibration 31
6.1.2 Yarn production 32
6.2 From fibre assemblies to composite materials 33
6.2.1 Fibre part 33
6.2.2 Matrix part 34
6.2.3 Composite processing 35
6.2.4 Composite preparation in this study 37
7 Defibration methods 39
7.1 Combined physical and chemical treatments 39
7.2 Biotechnological treatments 41
7.3 The treatment procedures effect on cellulose crystallinity 44
8 Fibre strength in hemp 45
8.1 Effect of hemp cultivar and the Weibull distribution 45
Risø-PhD-11 3