Mechanical Properties of Epoxy-coated Sodium Hydroxide and Silane Treated Kenaf /Recycled Polyethylene Terephthalate (RPET) Composites: Effect of Chemical Treatment

Low thermal degradation of natural fibres at high temperatures (above 200 degrees C) and poor fibre/matrix interfacial adhesion leading to poor mechanical performance are some of the problems associated with natural fibres as reinforcement in engineering thermoplastic composites. The present research is aimed at addressing the aforementioned problem by incorporating chemically (alkali/silane) treated and epoxy resin coated kenaf fibres into recycled thermoplastic polyethylene terephthalate (RPET) at a processing temperature of 240 degrees C. The thermal, mechanical and morphology of the treated, untreated-coated and uncoated kenaf fibre/PET composites were studied. The results showed that epoxy-coated and chemical-treated kenaf fibres generally improved the thermal stability as well as the mechanical properties of the composite samples compared to untreated-uncoated kenaf composites. However, coated kenaf with epoxy resin were most effective in improving the thermal and mechanical properties of kenaf/RPET composite compared to sodium hydroxide and silane treatments. The best result was obtained for epoxy-coated kenaf followed by sodium hydroxide treated and silane treated kenaf composites. The uncoated-untreated kenaf composites showed inferior mechanical properties due to poor interfacial bonding and fibre decomposition.