Abstract
The aim of this study is to throw new light on the influence of moisture on the mechanical properties of hemp fibres. Indeed, the behaviour of plant-based fibres strongly depends on their humidity. Although this topic has been relatively well treated for the case of wood, the literature on fibre stemming from annual plants is unfortunately poor. This purpose is, however, of great importance, particularly in view of the production of high-performance composites. The influence of environmental conditions on the static and dynamic tensile moduli and the strength of elementary fibres are investigated using a versatile experimental setup. Novel equipment was also designed to measure the rotation of a fibre about its axis when it was subjected to static loading and moisture variations. Water sorption is shown to have a significant influence on the apparent tensile stiffness, strength and fracture mode of such fibres, and is also shown to act like an activator of the stiffening phenomena under cyclic loading. A remarkable increase in the fibre stiffness of up to 250% is measured. Significant longitudinal elongation, reaching a value in excess of 2%, is associated with this increase in stiffness. The absorption and desorption of moisture also lead to substantial rotation of the fibre about its axis. Water sorption certainly involves a modification of the adhesion between cellulose microfibrils and the amorphous matrix. Under cyclic loading, the cellulose microfibrils could be able to creep into the relaxed amorphous matrix, leading to their re-arrangement, with more parallel orientations with respect to the fibre axis.
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References
Davies GC, Bruce DM (1998) Text Res J 68(9):623
Symington MC, Banks WM, West OD, Pethrick RA (2009) J Comp Mater 43(9):1083
Baley C, Morvan C, Grohens Y (2005) Macromol Symp 222:195
van Voorn B, Smit HHG, Sinke RJ, de Klerk B (2001) Composites: Part A 32:1271
Stamboulis A, Baillie CA, Peijs T (2001) Composites: Part A 32:1105
Astley OM, Donald AM (2001) Biomacromolecules 2:672
KhM Mannan, Robbany Z (1996) Polymer 37(20):4639
Lee JM, Pawlak LJ, Heitmann JA (2010) Mater Charac 61(1):507
Lee JM, Pawlak LJ, Heitmann JA (2007) Mater Sci Eng A 445–446:632
Pejic BM, Kostic MM, Skundric PD, Praskalo JZ (2008) Bioresour Technol 99:7152
Watt IC, Kabir M (1975) Text Res J 45(1):42
Saikia D, Bora MN (2003) Indian J Pure Appl Phys 41(6):484
Bourmaud A, Morvan C, Baley C (2010) Ind Crop Prod 32:662
Placet V, Passard J, Perré P (2008) J Mater Sci 43:3210. doi:10.1007/s10853-008-2546-9
Assor C, Placet V, Chabbert B, Habrant A, Lapierre C, Pollet B, Perré P (2009) J Agric Food Chem 57(15):6830
Thygesen A (2006) Properties of hemp fibre polymer composites: an optimisation of fibre properties using novel defibration methods and fibre characterisation. PhD thesis, The Royal Agricultural and Veterinary University of Denmark, p 146
Duval A, Bourmaud A, Augier L, Baley C (2011) Mater Lett 65:797
Baley C (2002) Composites: Part A 33:939
Charlet K, Eve S, Jernot JP, Gomina M, Bréard J (2009) Procedia Eng 1:233
Charlet K, Baley C, Morvan C, Jernot JP, Gomina M, Bréard J (2007) Comp Part A 38:1912
Nilsson T, Gustafsson PJ (2007) Composites: Part A 38:1722
Placet V (2009) Composites: Part A 40:1111
Hearle JWS (1963) J Appl Polym Sci 7:1207
Placet V, Bouali A, Perré P (2011) Matériaux Tech. doi:10.1051/mattech/2011120
Obataya E, Norimoto M, Gril J (1998) Polymer 39(14):3059
Placet V, Trivaudey F, Cisse O, Guicheret-Retel V, Boubakar ML (2012) Composites: Part A 43:275
Silva FA, Chawla N, Toledo Filho RD (2008) Comp Sci Tech 68:3438
Kompella MK, Lambros J (2002) Polym Test 21:523
Mc Laughlin EC, Tait RA (1980) J Mater Sci 15:89. doi:10.1007/BF00552431
Virk AS, Hall W, Summerscales J (2010) Comp Sci Tech 70:995
Virk AS, Hall W, Summerscales J (2009) Composites: Part A 40:1764
Joffe R, Andersons J, Wallström L (2003) Composites: Part A 34:603
Silva FA, Chawla N, Toledo Filho RD (2009) Mat Sci Eng A 516:90
Placet V, Bouali A, Garcin C, Cote JM, Perré P (2011) Suivi par DRX des réarrangements microstructuraux induits par sollicitations mécaniques dans les fibres végétales tirées du chanvre. 20th CFM, Besançon
Matinschitz KJ, Boesecke P, Garvey CJ, Gindl W, Keckes J (2008) J Mater Sci 43:350. doi:10.1007/s10853-006-1237-7
Kölln K, Grotkopp I, Burghammer M, Roth SV, Funari SS, Dommach M, Müller M (2005) J Synchrotron Radiat 12:739
Astley OM, Donald AM (2003) J Mater Sci 38:165. doi:10.1023/A:1021186421194
Placet V (2010) Tensile behaviour of natural fibres. Effect of loading rate, temperature and humidity on the “accommodation” phenomena. 14th ICEM, Poitiers, France
K. Charlet (2008) Contribution à l’étude de composites unidirectionnels renforcés par des fibres de lin: relation entre la microstructure de la fibre et ses propriétés mécaniques. PhD thesis, University of Caen, France
Bergfjord C, Holst B (2010) Ultramicroscopy 110:1192
Acknowledgements
The authors would like to thank Jean-Marc Côte and Camille Garcin from the FEMTO-ST for their assistance with some of the experiments, and Patrick Perré from the Ecole Centrale de Paris (Laboratoire de Génie des Procédés et Matériaux—Material Processes Engineering Laboratory) for their very fruitful and helpful discussions. We also thank Christine Millot for her technical contribution to the SEM characterisation of elementary fibres.
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Placet, V., Cisse, O. & Boubakar, M.L. Influence of environmental relative humidity on the tensile and rotational behaviour of hemp fibres. J Mater Sci 47, 3435–3446 (2012). https://doi.org/10.1007/s10853-011-6191-3
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DOI: https://doi.org/10.1007/s10853-011-6191-3