Wollastonite and talc reinforced polypropylene hybrid composites: Mechanical, morphological and thermal properties

Abstract

This study focused on evaluating the mechanical, thermal, and morphological properties of polypropylene (PP) hybrid composites containing two different inorganic mineral fillers, namely wollastonite (WO) and talc. The composites were prepared by melt mixing process using a twin screw extruder and an injection molding machine. All composites contained a constant filler loading at 20 wt% with varying WO/talc weight ratios (20/0, 15/5, 10/10, 5/15, and 0/20). Melt flow index (MFI), mechanical properties (impact strength and tensile properties), heat distortion temperature (HDT) fractured surface morphology, and thermal behaviors of the resulting composites were investigated. The results revealed an enhancement in the MFI, HDT, impact strength, Young’s modulus, crystallization temperature, melting temperature, and degree of crystallinity with a decline in the elongation at break and a small increase in the tensile strength of the composites compared to those of the pure PP. These were according to the lubricating effect (increased flowability), reinforcing effects (increased mechanical properties), barrier properties (increased HDT and melting temperature), and nucleating effect (increased crystallization temperature and crystallinity) of the fillers.