THE COMPONENT DISTRIBUTION, COMPATIBILITY AND CRYSTALLIZATION BEHAVIOR OF IPP/HDPE/EPDM TERNARY BLENDS
iPP/HDPE/EPDM三元共混体系的组分分布、相容性和结晶行为

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.