In this article, the effect of alkali treatment (with 5 wt. % sodium hydroxide solution for 30 min) on the compressive, in-plane shear, impact properties and vibration characteristics of flax- and linen-fabric reinforced epoxy composites was investigated. Test results show that alkali treatment enhanced the compressive strength and compressive modulus, in-plane shear strength and shear modulus, and specific impact strength of both flax- and linen-epoxy composites. However, after the treatment, the impact strength and damping ratio of the flax and linen composites decreased. The reduction in impact strength and damping ratio is believed to be attributed to the improved fibre/matrix interfacial adhesion, as analysed by scanning electron microscope.
SinghaAThakurV. Mechanical properties of natural fibre reinforced polymer composites. Bull Mater Sci2008; 31: 791–799.
2.
Herrera-FrancoPValadez-GonzalezA. A study of the mechanical properties of short natural-fiber reinforced composites. Composites Part B2005; 36: 597–608.
LiuQStuartTHughesM. Structural biocomposites from flax – part II: the use of PEG and PVA as interfacial compatibilising agents. Composites Part A2007; 38: 1403–1413.
5.
CarusMScholzL. Targets for bio-based composites and natural fibres. Biowerkstoff Report. ISSN 1867-1217, ed 8, March 2011, p.24.
6.
KuHWangHPattarachaiyakoopN. A review on the tensile properties of natural fibre reinforced polymer composites. Composites Part B2011; 42: 856–873.
7.
RomhányGKarger-KocsisJCzigányT. Tensile fracture and failure behavior of technical flax fibres. J App Polym Sci2003; 90: 3638–3645.
8.
BosH-LMolenveldKTeunissenW. Compressive behaviour of unidirectional flax fibre reinforced composites. J Mater Sci2004; 39: 2159–2168.
9.
Van de WeyenbergIIvensJDe CosterA. Influence of processing and chemical treatment of flax fibres on their composites. Compos Sci Technol2003; 63: 1241–1246.
AssararMScidaDEl MahiA. Influence of water ageing on mechanical properties and damage events of two reinforced composite materials: Flax–fibres and glass–fibres. Mater Des2011; 32: 788–795.
12.
Van VuureA-WKoF-KBeeversC. Net-shape knitting for complex composite preforms. Textile Res J2003; 73: 1–10.
13.
LiuQHughesM. The fracture behaviour and toughness of woven flax fibre reinforced epoxy composites. Composites Part A2008; 39: 1644–1652.
YanLBChouwNYuanXW. Improving the mechancial properties of natural fibre fabric reinforced epoxy composites by alkali treatment. J Reinf Plast Compos2012; 36: 425–437.
16.
ASTM. Standard test mothods for density and specific gravity of plastics by displacement. ASTM D792. Philadelphia, PA: ASTM, 2008.
17.
ASTM. Standard test mothods for void content of reinforced plastics. ASTM D2734. Philadelphia, PA: ASTM, 2009.
18.
Heslehurst RB. Composite structures engineering design vs. fabrication requirements. In: ACUN-5 International Composites Conference. Developments in Composites: Advanced, Infrastructure, Natural and Nano-composites. Sydney, Australia, 11–14 July, 2006. Sydney, Australia: UNSW.
19.
ASTM. Standard test mothods for compressive properties of polymer matrix composite materials with unsupported gage section by shear loading. ASTM D3410. Philadelphia, PA: ASTM, 2008.
20.
ASTM. Standard test methods for in-plane shear response of polymer matrix composite materials by tensile test of a ±45° laminate. ASTM D3518. Philadelphia, PA: ASTM, 2007.
21.
ASTM. Standard test methods for determining the izod pendulum impact resistance of plastics. ASTM D256. Philadelphia, PA: ASTM, 2010.
22.
Gibson RF, Hwang SJ and Kwak H. Micromechanical modeling of damping in composites including interphase effects. In: Proceedings of the 36th International Society for the Advancement of Material and Process Engineering Symposium. San Diego, USA, 15–18 April, 1991, pp. 592–606.
