Compatibility of iPP/HOCP binary blends by OM, DSC, DMTA and C-13 nuclear magnetic resonance

The study of miscibility of the isotactic polypropylene (iPP)/hydrogenated oligo(cyclopentadiene) (HOCP) blends was performed by using OM, DSC, DMTA and C-13 NMR techniques. The proton spin-lattice relaxation time in the rotating frame by using C-13 spectra cross-polarization/magic-angle spinning (CP/MAS) of iPP, HOCP and their blends were determined These blends showed phase separation. Two amorphous phases were observed: one rich in the high molecular weight component (iPP) and another one rich in the low molecular weight component (HOCP). This behaviour was similar to one observed for HDPE/HOCP blends. The results indicated that compression moulded samples of iPP/HOCP blends formed a partially miscible system, while in literature it was found that extruded isotropic films of this blend displayed as a miscible system. The iPP-HOCP interaction is influenced by the composition, the crystallization process, the solidification time and the specimen preparation.