The component distribution

cpmpatibility and crystallization behavior of the polyolefin blends of isotactic polypropylene (IPP)

high density polyethylene (HDPE) and ethylene-pro-pylene-diene terpolymer (EPDM) were investigated by means of differential scanning calori-metry (DSC)

13C-nuclear magnetic resonance (13C-NMR)

scanning electron microscopy (SEM) and wide-angle X-ray diffraction (WAXD). EPDM with high ethylene content was more compatible with PE component than PP component in the blends and its molecular seg-ments mostly distributed in PE component. The ternary blend containing 15% of EPDM had hest best compatibility

exhibiting a interconnecting structure of domains of crystals in the SEM micrograph. The overall crystallinity (Xc) decreased with increasing EPDM content

which was ascribed to the facts that the crystallinity of PE component (XCE) decreased significan-tly and that of PP component (XGP) was almost unchanged. The results were explained on the basis of the difference in compatibility of EPDM with PE and PP as well as the different cry-stallization behavior of semicrystalline components in the course of cooling.