Abstract: The melt reactive blending and dynamic mechanical properties of HIPS/PP blendsin the presence of dicumyl peroxide(DCP) were studied.The results show that the degradation of PS was the main process in HIPS/DCP mixture while the cross-linking and graftingare the predominate in the PB phases.PP was degraded when it was "dxed with DCP inmolten state.However, the grafting of PP onto HIPS was a main process in HIPS/PP/DCPblends.The characteristic of molecular motion in HIPS/PP/DCP blends is significantly different from that in HIPS/PP blends.The glass transition temperature of PS phase was decreased and that of PB and PP phases were increased.The melt reaction mixing of HIPS/PPblends led to the in-situ compatibilization.

Key words: high impact polystyrene, polypropylene, reactive compatibilization, dynamic mechanical property