Abstract: Polypropylene(PP) was melt grafted with 1,6hexanediol diacrylate (HDDA) and styrene in order to increase the melt strength. β nucleating agent was added to the reaction system to change the crystalline of PP. The influences of screw speed, dosage of initiator, molar ratio of monomers, and material mass on melt flow rate and melt strength were studied. The structure and properties of modified PP were analyzed using infrared spectroscopy, thermalgravimetric analysis, and Xray diffraction. The melt flow rate and melt strength of grafted PP were 0.70 g/10 min and 10.00 kPa·s, respectively. The heat stability was also improved through the grafting.

Key words: polypropylene, melt strength, β nucleating agent, reacting extrusion, long chain branched