Effect of Alkaline Treatment to Wettability and Flexural Properties of Kenaf Nonwoven Fibre Mat Reinforced Epoxy Composites Produced by Resin Transfer Moulding

Abstract

This paper focuses on the study of the effect of chemical treatments of fibres by alkalization on the flexural and impact properties of epoxy matrix composites reinforced by kenaf fibre (KF) produced via resin transfer moulding (RTM) technique. The reinforcement consists of KF nonwoven fiber mat fabricated using needle punching method. Prior to punching process, KF are subjected to alkali treatments with Sodium hydroxide (NaOH) at 3, 6 and 9% for a period of 3h at room temperature. The composites were reinforced with kenaf nonwoven mat at 40% by volume. Effect of alkaline treatment concentration to wettability of KF towards epoxy resins are measured by means of contact angle and surface energy analysis. Influences of alkaline treatment on the flexural properties are studied to determine the optimum conditions of alkaline treatment. As concentration of NaOH in alkaline treatment increased, the experimental results show that the flexural properties of composites increases. For 6% NaOH treatment, the flexural strength and flexural modulus improved by 7.88 MPa to 81.38 Mpa and from 4.79 GPa to 5.41GPa compared to untreated fibre composites. However, as the concentration of NaOH increase to 9%, the bending properties reduced significantly.