The role of molecular parameters of PP in the sensitivity to specific nucleation

Abstract

The efficiency of β-nucleating agent (NU 100) in commercial isotactic polypropylenes (PP) differing in melt flow indexes (MFI) was analyzed. Polymorphic composition of neat PP and PP containing 0.01 and 0.03 wt.% of NU 100 was analyzed using wide-angle X-ray scattering and differential scanning calorimetry. Morphology was observed by polarized-light microscopy. MFI influenced the β-phase formation only with 0.01 wt.% of NU 100: The step change of β-phase content between PP with MFI 1 and 12 was observed. A significant effect of final temperature of heating on β-phase formation in the samples was detected. PP containing 0.03 wt.% of NU 100 crystallized into β-phase.