Abstract: PP was grafted with N-phenyl maleimide(N-PMI) and diphenylmethyene bismaleimide (BMI) in order to enhance its polarity. Infrared spectrum (FTIR) confirmed the grafting. The contacting angle of DI water on samples changed from 109 o for neat PP to 97 o for 2 phr N-PMI grafted and to 99 o for 1 phr BMI grafted. At processing temperature, the phthalimide(PTI) could be dissolved into grafted PP to enhance its flow ability, and at reduced temperature, PTI was phase separated and thus to improve the heat distortion temperature and impact strength. With 2 phr N-PMI, 1 phr BMI, and 1 phr PTI, the melt flowing rate of the resultant system was 2 times higher than that of neat PP while the heat distortion temperature increased 12 ℃, impact strength and flexural strength increased 20 % and 10 % , respectively.

Key words: melting graft, modification, melt fluidity, polypropylene, maleimide, phthalimide