Application of different macrokinetic models to the isothermal crystallization of PP/talc blends

The crystallization kinetics of neat polypropylene (PP) and of PP composites containing 2, 5, 10 and 30 wt% of talc was studied. Various kinetic equations, namely the Avrami, Velisaris-Seferis, Dietz, Khanna, Malkin models, have been applied to describe the kinetics of crystallization from the melt state under isothermal conditions. The results suggested that experimental data of the Avrami's exponent, "n", is approximately 2, meaning that the crystallization of PP alone and of its composites with talc is a two-dimensional growth process. Experimental data of PP alone can be best described by the Avrami, Velisaris-Seferis, Dietz and Malkin models; whereas the models that in the case of composites better correlate their behavior are those of Velisaris-Seferis, followed by Avrami's. (C) 2003 Elsevier Ltd. All rights reserved.