Small angle scattering study of the structure of isotactic polypropylene-hydrogenated oligo(cyclopentadiene) blends

Blends of isotactic polypropylene (iPP) and hydrogenated oligo cyclopentadiene (HOCP) have been studied by means of small angle X-ray scattering in the temperature range 70-160 degrees C. The structure of blends containing less than 25% HOCP is very similar to the one of plain iPP, i.e. lamellae whose thickness increases by increasing the temperature. Blends containing more than 25% HOCP are characterized by two kinds of lamellae formed by layers of iPP and amorphous material rich in iPP and in HOCP, respectively. The crystallizable iPP present in both phases crystallizes from the melt, in analogy to what happens in HDPE/HOCP blends and in agreement with the values of the crystallinity referred to the crystallizable polymer, that is almost constant with composition for both blends.