Abstract: In order to develop a type of thermoplastic materials used for automobile rear door panels, a polypropylene (PP)-based composite was prepared via melt blending by using POE as an impact modifier and talcum powders as an inorganic filler. Effects of stain speed and test temperature on tensile strength and effect of talcum content on mechanical properties and linear expansion coefficient were investigated extensively. The results indicated that tensile strength of the composites increased with an increase of strain rate, but the elongation at break showed an increase at first and then tended to decrease. On the other hand, the tensile strength decreased with increasing test temperature. With increasing content of talcum powders the flexural modulus increased, the impact strength decreased, and linear expansion coefficients also decreased. The optimum content of talcum powders in this material was determined as 20 wt % when being used for automobile rear door panels.

Key words: thermoplastic polyolefin, talcum powder, mechanical property, linear expansion coefficient