Performance of potassium titanate whisker reinforced polyamide-6 composites

Composites of polyamide-6 reinforced with potassium titanate whiskers were prepared in a twin-screw extruder, followed by injection moulding. The whiskers were surface treated with tetrabutyl orthotitanate prior to blending. The tensile, impact, morphology and thermal properties of the injection moulded composites were investigated. Static tensile measurements showed that the tensile strength and modulus of the composites increased with increasing whiskers content. However, Izod impact tests indicated that the composites showed a decrease in the impact strength initially with whiskers content up to 25 wt%; thereafter they showed a slight increase when the whiskers content reached 35 wt%. Scanning electron microscopic observations revealed that the whiskers within the composites were oriented uniformly along the melt flow direction. Finally, thermogravimetric analysis showed that the heat resistance of the composites tended to increase with increasing whiskers content. The results were analysed and discussed in terms of established models of the behaviour of short-fibre reinforced composites.