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

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Hemp fiber microstructure and use of fungal defibration to obtain fibers for composite materials Anders Thygesen *1,2 , Geoffrey Daniel 3 , Hans Lilholt 1 , Anne Belinda Thomsen 4 1 Risø National Laboratory, Materials Research Department, P.O. Box 49, DK-4000 Roskilde, Denmark. 2 The Royal Veterinary and Agricultural University, Danish Centre for Forest, Landscape and Planning, Højbakkegårds Allé 1, DK-2630 Tåstrup, Denmark 3 Swedish University of Agricultural Sciences, WURC, P.O. Box 7008, SE-75007 Uppsala, Sweden. 4 Risø National Laboratory, Biosystems Department, P.O. Box 49, DK-4000 Roskilde, Denmark. *Corresponding Author: Anders Thygesen: Fax: +45 46775758 Academic degrees, professional titles and e-mail addresses: M.Sc., Ph.D student Anders Thygesen, E-mail: anders.thygesen@risoe.dk Dr., Professor Geoffrey Daniel , E-mail: geoff.daniel@trv.slu.se M.Sc., Ph.D, Senior scientist Hans Lilholt, E-mail: hans.lilholt@risoe.dk M.Sc., Ph.D, Senior scientist Anne Belinda Thomsen, E-mail: anne.belinda.thomsen@risoe.dk Journal: Journal of Natural Fibres, In press. 90 Risø-PhD-11
ABSTRACT Characterization of hemp fibers was carried out to investigate the mild defibration with Phlebia radiata Cel 26, a fungus which selectively degraded the epidermis and the lignified middle lamellae. Thin fiber bundles could thereby be produced. The single fiber S2 layer consisted of 1-5 μm thick concentric layers constructed of ca. 100 nm thick lamellae. The microfibril angle showed values of 0-10° for the main part of S2 and 70- 90° for S1. The low S2 microfibril angle resulted in fiber bundles with high tensile strength (960 MPa) decreasing to 850 MPa after defibration due to degradation of non cellulosic components. Key words: Cannabis sativa L., bast fibers, cell wall structure, microfibril angle, electron microscopy, histochemistry, Phlebia radiata Cel 26. ACKNOWLEDGEMENTS This work forms part of the project "High performance hemp fibers and improved fiber network for composites" supported by the Danish Research Agency of the Ministry of Science, the EU COST action E20 and the Wood Ultrastructure Research Center (WURC), Sweden. The support to Ph. D. student Anders Thygesen from WURC is gratefully acknowledged. Senior scientist Poul Flengmark (Danish Institute of Agricultural Sciences) is acknowledged for growing the hemp, Mrs. Ann-Sofie Hansen (WURC) for setting up the fungal cultivations, M. Sc. Frants T. Madsen (The Royal Veterinary and Agricultural University) for instruction in fiber bundle testing and Mr. Henning K. Frederiksen (Risø National Laboratory) for help in composite fabrication. Dr. Claus Felby (The Royal Veterinary and Agricultural University) is acknowledged as supervisor for Anders Thygesen. Risø-PhD-11 91
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Risø-PhD-11(EN) Properties of hemp
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Contents Preface 6 1 Resumé 7 2 Li
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PhD thesis: Properties of hemp fibr
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1 Resumé Karakterisering af hampef
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2.4 Oral presentations Anders Thyge
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4 Introduction Hemp (Cannabis sativ
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4.2 The outline of the thesis The f
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The only fertilizer used was 360/48
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Temperature [ o C] 35 30 25 20 15 1
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A B Figure 7. A: Model of transvers
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Figure 8. Lignin (a), pectin (b) an
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Figure 11. Microfibril angles (MFA)
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Teleman, 1997). The crystal structu
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to the computing effort and the sub
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Figure 15. The structure of hemicel
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fibre mats, which are made by air-d
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Figure 18. From fibre filament to a
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A B C D Figure 20. Chemical structu
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water vapour and air are removed fr
Page 39 and 40: 7 Defibration methods Defibration m
Page 41 and 42: Table 5. Fibre yield and cellulose
Page 43 and 44: a b c Composition [% w/w] 100 Compo
Page 45 and 46: 8 Fibre strength in hemp The streng
Page 47 and 48: 8.2 Effect of pre-treatment of hemp
Page 49 and 50: E-modulus [GPa] 90 80 70 60 50 40 3
Page 51 and 52: Second mode: Failure is controlled
Page 53 and 54: structure, which made much higher f
Page 55 and 56: Table 7. Porosity factors determine
Page 57 and 58: Thereby, the effective fibre streng
Page 59 and 60: a b Composite tensile strength σcu
Page 61 and 62: Table 9. Mechanical properties in a
Page 63 and 64: a σ c/ρ c [10 3 m 2 /s 2 ] b Ec/
Page 65 and 66: Fibre strength σ f [MPa] Fibre sti
Page 67 and 68: 11 References Andersen TL, Lilholt
Page 69 and 70: Kaar WE, Cool LG, Merriman MM, Brin
Page 71 and 72: Stowell EZ, Liu TS, 1961. On the Me
Page 73 and 74: Appendix A: Comprehensive composite
Page 75 and 76: The porosity constants can now be d
Page 77 and 78: Appendix D: Density and mechanical
Page 79 and 80: Paper I Changes in chemical composi
Page 81 and 82: Risø-PhD-11 81
Page 89: Paper II Hemp fiber microstructure
Page 93 and 94: METHODS AND TECHNIQUES Treatment of
Page 95 and 96: 2000) and their orientation gave th
Page 97 and 98: By TEM microscopy, the single fiber
Page 99 and 100: Table 1. Chemical composition of th
Page 101 and 102: Table 2. Tensile strength (σ) and
Page 103 and 104: Morvan, C., Jauneau, A., Flaman, A.
Page 119 and 120: Paper IV Comparison of composites m
Page 121 and 122: ABSTRACT Aligned epoxy-matrix compo
Page 123 and 124: the calculation of volume fractions
Page 125 and 126: solution (pH 4) for 4 h at 85°C. L
Page 127 and 128: E ⎛ dσ c ⎞ = ⎜ ⎟ ⎝ dε
Page 129 and 130: Table 2. Chemical composition, stru
Page 131 and 132: transverse section of the small hem
Page 133 and 134: Long fibres that pass through the e
Page 135 and 136: Figure 6. Effect of composite fabri
Page 137 and 138: DISCUSSION The defibration of hemp
Page 139 and 140: This investigation showed that the
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Bos, H.L., Molenveld, K., Teunissen
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Thygesen, A., 2006. Properties of h
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Risø-PhD-11 145
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Risø’s research is aimed at solv
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