Thermal properties and phase structure of PP plus oligopinene blends

Blends of polypropylene (PP) and beta -oligopinene, a synthetic low molar m ass resin, were prepared by melt mixing in a Haake Rheocord at 473 K, 30 rp m during 600 s. The influence of the terpenic resin on the thermal properti es, phase structure and crystallization of PP was evaluated. The DSC result s indicated the presence of phase separation. The SEM analysis shows that t he oligopinene was extracted along the whole surface and it was observed en tities as cut cylinder atributted to low molar mass PP. The isothermal crys tallization of blends was conducted at 396, 398 and 403 K. The mixtures did not show phase separation in molten, during crystallization and after soli dification. The spherulite radial growth rate of PP decreased and was depen dent on the temperature and composition. The results indicated that the sys tem is an immiscible blend with at least three phases: a fine dispersion of the oligopinene in the amorphous PP, some boundary solubility of PP in oli gopinene and a crystalline PP.