Isotactic Polypropylene/hydrogenated oligo(cyclopentadiene) blends: influence of annealing on crystal and phase structure.

The influence of annealing on phase structure and morphology of isothermally crystallized samples of isotactic polypropylene/hydrogenated oligocyclopentadiene (iPP/HOCP) blends was investigated by using wide- and small-angle X-ray scattering methods and differential scanning calorimetry. The two components are melt-compatible; moreover during crystallization of iPP the molecules of HOCP are mainly ejected in interlamellar regions where they form a homogeneous phase with uncrystallized iPP molecules or part of them. It was found that the presence of such molecules in interlamellar regions determines a loss of thickening tendency of crystalline lamellae following the annealing. The amount of this effect is dependent on composition and undercooling.