Isotactic polypropylene/hydrogenated oligo(cyclopentadiene) blends: phase diagram and dynamic-mechanical behaviour of extruded isotropic films

The phase structure and the dynamic-mechanical properties of isotropic films of isotactic polypropylene iPP)/hydrogenated oligocyclopentadiene (HOCP) blends are reported. It is found that the phase diagram presents both the lower critical solution temperature and the upper critical solution temperature. The dynamic-mechanical tests (performed at a frequency of 1 Hz and at a heating rate of 4°C min-1) show that the addition of HOCP > 20 wt% causes an increase of the storage modulus at low temperatures; the curves of storage modulus and loss modulus of the isotropic films containing HOCP > 20 wt% show the transition of the smectic form of iPP to the crystalline ? form