CRYSTALLIZATION, MELTING BEHAVIOR, AND MORPHOLOGY OF BPP HDPE BLEND/

The crystallization, melting behavior, and morphology of a low ethylen e content block propylene-ethylene copolymer (BPP) and a high-density polyethylene (HDPE) blend were studied. It was found that the Existenc e of ethylene-propylene rubber (EPR) in BPP has more influence on the crystallization of HDPE than on that of PP. This leads to the decreasi ng of the melting temperature of the HDPE component in the blends. It is suggested that the EPR component in BPP shifted to the HDPE compone nt during the blending process. The crystallinity of the HDPE phase in the blends decreased with increasing BPP content. The morphology of t hese blends was studied by polarized light microscopy (PLM) and SEM. F or a BPP-rich blend, it was observed that the HDPE phase formed partic les dispersed in the PP matrix. The amorphous EPR chains may penetrate into HDPE particles to form a transition layer. (C) 1998 John Wiley & Sons, Inc.