Supermolecular structure of polyolefin blends

Phase composition and structural heterogeneity of fibers made of polyolefin mixtures, polyethylene: polypropylene, polyethylene: poly(4-methyl pentene-1), and polypropylene: poly(4-methyl pentene-1), were studied by WAXS and SAXS. It was discovered that the heterogeneity of the polymer blends was higher than the additive heterogeneity of the components. In some cases, e.g., in polyethylene: poly(4-methyl pentene-1) and polypropylene: poly(4-methyl pentene-1) blends, the high heterogeneity was due to additional dispersion of the admixed polymer, whereas in other cases (e.g., in polyethylene: polypropylene blends) it could be explained by the formation of microvoids, which were about 0.5% of the polymer volume