Effect of glass fibre hybridization on the water absorption and thickness of alkali treated kenaf-epoxy composites

Abstract

Abstract Natural and synthetic fibre reinforced hybrid polymer composites have attracted significant attention due to their combined benefits of biodegradability and strength. Kenaf fibres have the potential to replace synthetic fibres in polymer composites due to their excellent mechanical properties. However, their use for high strength and water resistance applications are not found suitable due to their hydrophilic nature. The main aim of this study is to reduce the water absorption capacity of kenaf fibre composites through alkali treatment and glass fibre hybridization. The continuous fibre, alkali treated, unidirectional kenaf-glass–epoxy hybrid composites (K untreated, K Treated, G/K/G, G/K/G/K/G, G) were prepared by the hand lay-up method and their water absorption and thickness swelling behaviour studied. Thereafter the diffusion properties like diffusion coefficient (Dc), corrected diffusion coefficient (Dcc), sorption coefficient (Sc) and permeability coefficient (Pc) of above composites were also calculated. The results show that alkali treated hybrid composites with stacking sequence G/K/G/K/G exhibited the lowest water absorption and thickness swelling capacity in comparison to kenaf fibre composites. The alkali treated kenaf fibre composites reduced the water absorption and thickness swelling capacity by 23% and 13% respectively compared to untreated kenaf fibre composites while the glass fibre hybridization further reduced the water uptake and thickness swelling by 35% and 32% respectively as compared to alkali treated kenaf fibre composites.