COMPATIBILITY OF BINARY BLENDS OF POLYPROPYLENE WITH ETHYLENE-ALPHA-OLEFIN COPOLYMER

The compatibility for binary blends of isotactic polypropylene with ru bbery ethylene-a-olefin copolymers having various alpha-olefin content s was investigated by means of differential scanning calorimetry, X-ra y analysis, transmission electron microscopy, and dynamic mechanical a nalysis. It was found that ''alpha-olefin rich'' in ethylene-1-butene copolymers and in ethylene-1-hexene copolymers were miscible with amor phous polypropylene chains, when the alpha-olefin content is above 50 mol %. On the other hand, the blends with ''ethylene rich'' (above 50 mol % of the ethylene content) in ethylene-1-butene copolymers and eth ylene-1-hexene copolymers showed a microheterogeneous morphology. (C) 1996 John Wiley & Sons, Inc.