STRUCTURE AND PROPERTIES OF POLYOLEFIN BLENDS

Blends of ethylene-propylene-diene rubber (EPDM) and low density polye thylene (PE(1d)) or isotactic polypropylene (iPP) crosslinked by dicum yl peroxide (DCP) have been prepared. Their morphology, reactivity of the components and crystallinity have been studied. The blends are mic roheterogeneous. Both plastomers, but particularly iPP, decrease the c rosslinking efficiency of EPDM by DCP. It was found that they also inf luence the mechanical properties of the blends. The effect of iPP is f ar more pronounced than that of PE(1d), because of an increase in crys talline phase content. iPP particles play a role as nuclei for propyle ne monomer units in EPDM, whereas PE(1d) particles are solvated by the elastomer-matrix.