The Structure and Properties of Impact Copolymer Polypropylene

The structure and mechanical properties of four impact copolymer polypropylenes with different ethylene content made by circular tube reactor have been characterized by IR,GPC,SEM,DSC,DMA(Dynamical mechanical analysis),Tension,Izod Impact Tester etc.DMA curves revealed the presence of two Tg peaks in all samples indicating the amorphous phases of ethylene-propylene rubbers and PP.As ethylene content increase,Izod impact strength(at 23 ℃ and-20 ℃) increases while the tensile stress、Young′s modulus、flexural strength、Flexural modulus 、Heat deformation temperature、brittle temperature and Rockwell Hardness decreases.Fine and uniform dispersion were observed by SEM,ethylene-propylene rubbers of four impact copolymer polypropylenes are uniformly dispersed with average particle size ranged from about 0.48 to around 0.61 micrometers.The crystallinity、ΔHm、ΔHc of four impact copolymer polypropylenes as measured with differential scanning calorimery decrease with increasing ethylene content.