Influences of isotactic poly(4-methylpentene-1) on the crystallization and morphology of the β-nucleated isotactic polypropylene

The β-nucleated isotactic polypropylene (β-iPP)/isotactic poly(4-methylpentene-1) (TPX) composites were prepared using a β-nucleating agent (TMB-5). The crystallization behavior and polymorphic morphology of β-iPP with various concentration of TPX were investigated by differential scanning calorimetry, wide-angle X-ray diffraction, and scanning electronic microscopy. The results showed that the addition of TPX increases the content and the spherulite sizes of β-phase but decreases the crystallization temperature and reduces the crystallization energy barriers as well. For melting behavior, it was found that the β-phase content of samples greatly depend on the cooling rate applied and the appearance of TPX.