PP／EPR in situ blends were prepared by the sequential polymerization technique using a Ziegler-Natta catalyst MgCl2

TiCl4／BMF(BMF is 9

9-bis(methoxymethyl)fluorine as an internal donor)．The content of ethylene unit in blends was adjusted by modifying the time of ethylene—propylene copolymerization．The structure and morphology characters of the blends obtained were investigated by nuclear magnetic resonance(NMR)

gel permeation chromatography(GPC)

dynamic mechanical analysis(DMA)

differential scanning calorimetry(DSC)

scanning electron microscopy(SEM)and polarized light microscopy(PLM)．The results suggested that PP/EPR is a complex multiphase mixture including PP

EPR and EP block copolymer The presence of EP block copolymer greatly improved the compatibility between the PP matrix and the EPR dispersed phase in the muhiphase system．The compatibility between the PP matrix and the EPR dispeersed phase in the muhiphase system．The change of the ethylene unit content in PP／EPR remarkably influenced the crystalline morphology of PP with increasing the content of ethylent unit in the blend

the PP spherulites became smaller and irregular．