Effect of Graphene Nano-fillers on Mechanical and Thermal Properties of Polypropylene (PP)/Pineapple Leaf Fibre (PALF) Composites

Abstract

Polypropylene (PP) is a popular commodity plastic due to having relatively good mechanical properties and processability. However, further modification of PP is needed in order to compete with engineering polymers. In this study, pineapple leaf fibre (PALF) and graphene are being incorporated to enhance properties without increasing the cost significantly. The PP composites were prepared with different graphene content (0.5, 1.0 and 2.0 phr) using melt blending method followed by injection moulding and the neat PP and PP/PALF act as control. The main focus of this study was to investigate the effect of adding both fillers on mechanical strength and thermal properties of PP. Tensile test, impact test and thermal gravimetric analysis (TGA) were carried out to study the properties of PP composites. Results showed that tensile strength (MPa) and Young’s Modulus of PP increased by addition of PALF but decreased of elongation at break. The addition of graphene (0.5, 1.0 and 2.0 phr) on PP/PALF composite increased the Young’s Modulus and tensile strength but it decreased the percentage of elongation at break. From Impact test, the use of PALF had increased the impact strength of PP. The use of graphene on PP/PALF composite had also increased the impact strength. In general, higher content of graphene (2.0 phr) decreased the mechanical properties of PP/PALF composite. From TGA test, the maximum decomposition of PP occurred within temperature 475 to 480°C. The addition of PALF and graphene gave no significant changes to thermal properties of PP.