Influence of composition on the morphology, crystallization and melting behavior of isotactic polypropylene/isotactic poly(1-butene) blends

The crystallization and thermal behavior of blends of isotactic polypropylene (iPP) and isotactic poly(1-butene) (iPB) have been studied by differential scanning calorimetry and optical microscopy. The overall crystallization rate, the spherulite growth rate and the equilibrium melting temperature of iPP are decreased by the addition of iPB. The melting point depression of the iPP phase has been analyzed according to the Flory-Huggins theory and a negative interaction parameter has been found. These results are consistent with the miscibility of iPP and iPB in amorphous state.