Water absorption and its effect on mechanical properties of sisal composite

Apart from many applications of natural fibres reinforced polymer composites, still they are not being used in outdoor applications because of their higher water absorption thereby degradation in mechanical properties. The purpose of this study is to analyze the water absorption behaviour and its effect on tensile, flexural and impact properties of sisal composites. Water absorption characteristic parameters such as sorption, diffusion and permeability coefficient were also investigated. The composites were prepared by hand lay-up method followed by a constant loading with varying fibres lengths (i.e. 5, 10, 15 and 20 mm). In addition to this, fibres content was kept constant (i.e. 20 wt. %) in each composite. The results showed a significant effect of water absorption and fibres lengths on the mechanical properties of sisal composites. Mechanical properties were found to increase up to a certain fibres length (15 mm) and then decreased. On the other hand, mechanical properties of sisal composites were reduced after water absorption. There were (10–18)%, (10–21)% and (16–30)% deduction in tensile strength, flexural strength and impact strength respectively in sisal composites because of water absorption.