Abstract: In this paper, polypropylene/EPR in-situ alloys were prepared with ethylene contents of 0.94 mol%, 1.67 mol% and 3.00 mol%. Isothermal and non-isothermal crystallization behaviors of the samples were investigated using differential scanning calorimetry (DSC). The isothermal crystallization data was well fitted with Avrami equation. The higher the crystallization temperature, the lower the crystallization rate. For the non-isothermal crystallization, the range of crystallization temperature became wider and moved to lower temperature with increasing cooling rate. It was also found that the higher the content of ethylene, the lower the crystallization rate of isothermal crystallization, except the content of ethylene was 3.00 mol %, and the crystallization temperature of non-isothermal crystallization had the same regularity.

Key words: polypropylene, ethylene propylene random copolymer, alloy, isothermal crystallization, non-isothermal crystallization, Avrami equation