Effects of thermal cycling on physical and tensile properties of injection moulded kenaf/carbon nanotubes/polypropylene hybrid composites

Abstract Polymer as well as polymer composites are inclined to premature due to effect on mechanical and physical properties during service time. In this paper, the effect of thermal cycling (−30 to 80 °C) on the physical and tensile properties of Polypropylene (PP), Kenaf/PP, Kenaf/PP/CNTs and Kenaf/CNTs/MAPP/PP hybrid composites for the injection moulded car battery tray was investigated. Although this study had found no physical changes on the samples in terms of colour or cracking, the samples, however, had experienced warpage and dimensional changes. The dimension of samples containing CNT had increased by 20%, while the PP and PP/Kenaf samples had decreased by 3.5% and 87%, respectively. Although the process of thermal cycling was found to have rapidly decreased the hardness of Pure PP and Kenaf/PP composites, it had, however, gradually increased the hardness of composites with CNT fillers. The tensile strength, Young's modulus and elongation of the composites had also been examined in this research. Furthermore, according to the fractographic investigations using scanning electron microscope, it is perceived that the fracture morphology of the samples is strongly influensed by thermal cycling.