Isothermal and non-isothermal crystallization kinetics of polypropylene/exfoliated graphite nanocomposites

The crystallization behavior of polypropylene/exfoliated graphite nanocomposites prepared by melt compounding was analyzed using differential scanning calorimetry (DSC). Isothermal and non-isothermal experiments were used to evaluate the influence of exfoliated graphite (EG) content on the crystallization process of polypropylene (PP) from the molten state. The presence of exfoliated graphene layers in the polypropylene matrix modified was observed by transmission electron microscopy (TEM). The addition of exfoliated graphite dramatically modified the non-isothermal crystallization behavior of the PP matrix, increasing the crystallization temperature, crystallization rate, and degree of crystallinity. The Avrami analysis was applied under isothermal conditions and the model showed that graphite acted as a nucleating agent reducing the barrier to nucleation and modifying the crystallite structures of PP.