SUPERMOLECULAR STRUCTURE OF POLYOLEFIN BL ENDS

Phase composition and structural heterogeneity of fibers made of polyo lefin mixtures, polyethylene : polypropylene, polyethylene : poly(4-me thyl pentene), and polypropylene: poly(4-methyl pentene), were studied by WAXS and SAXS. It was discovered that the heterogeneity of the pol ymer blends was higher than the additive heterogeneity of the componen ts. In some cases, e.g., in polyethylene : poly(4-methyl pentene) and polypropylene : poly(4-methyl pentene) blends, the high heterogeneity was due to additional dispersion of the admixed polymer, whereas in ot her cases (e.g., in polyethelene : polypropylene blends) it could be e xplained by the formation of microvoids, which made about 0.5% of the polymer volume. Dispersion was accompanied by amorphization of the par ticles as confirmed by a decrease in the total and partial crystallini ties evidenced by X-ray diffraction analysis.