Surface modified carbon fibre reinforced PA6 and its blend-based composites

Abstract

Polyamide 6 (PA6) matrix-based composite system are widely used in automotive sector. PA6 can be directly used as matrix material, but for avoiding the moisture intake by PA6, Polypropylene (PP) has been used as a secondary polymer and PP grafted with maleic anhydride (PP-g-MA) has been used as compatibilizer. The use of carbon fibre as reinforcement increases the strength and stiffness of the composite. Laminate composites have been studied for automotive and wind turbine blade application. But, commercially injection moulding is used for making automobile components. In that case, short carbon fibre (SCF) can be used as reinforcement. In this study, the effect of surface treatment of SCF on mechanical properties of PA6 and its blend-based composites has been studied. Two types of modification have been compared viz., sizing and coupling agent. To investigate the effect of sizing and coupling agent, commercially available SCF was desized by thermal etching and then modified with suitable amount of epoxy and silane as sizing and coupling agent, respectively, and its effect on PA6 and modified PA6 matrix was studied. Mechanical properties and thermal properties of the composites were studied using tensile testing and DSC analysis. It was found that epoxy-based sizing is suitable for PA6 and silane-based coupling agent is suitable for blend-based PA6 matrix.