Abstract: In this paper, various behavior of homo-polypropylene and co-polypropylene were studied, including thermo-oxidant aging, stress white, post shrinkage after different treatment conditions, and dyeing. After thermo-oxidant aging, the impact strength of homo-polypropylene decreased remarkably, however, that of co-polypropylene increased up to 200 % at first, and then decreased slowly. The resistance to stress whitening of homo-polypropylene was better than that of co-polypropylene; After heat treatment and boiled in water, the post shrinkage of polypropylene with high crystallinity was lower than that of polypropylene with low crystallinity. When the blackness of polypropylene was larger, the hue was more bluish.

Key words: homo polypropylene, thermo-oxidant aging, stress white, post shrinkage, dyeing, co-polypropylene