Abstract:

The tensile and impact properties of polypropylene （PP）/recycled PP（RPP） blends were investigated in terms for the application requirement for automobiles， and their aging properties were also evaluated under the aging condition in a 100 °C hot air for 1 000 h. There was little effect on the tensile strength and impact strength of the blends at weight fractions of RPP less than 20 wt%. The tensile strength and impact strength of the blends decreased with an increase in the content of RPP， when the properties of pristine PP were superior to those of RPP. The blends exhibited a decrease in tensile strength and impact strength at first and then presented an increase trend when their properties were superior to those of RPP. However， the blends presented minimal tensile strength and impact strength at a PP/recycled PP weight ratio of 50∶50. The tensile strength and impact strength presented an upward trend after aging at 100 °C for 1 000 h，especially for the impact strength.

Key words: polypropylene, recycled material, mechanical property, aging