Non-isothermal melt crystallization kinetics for poly(trimethylene terephthalate)/poly(butylene terephthalate) blends

Various macrokinetic models, namely the Avrami, Ozawa, and Ziabicki models, were applied to describe the non-isothermal melt crystallization process of poly(trimethylene terephthalate) (PTT), poly(butylene terephthalate) (PBT), and their blends. Both the Avrami and the Ozawa models were found to describe the experimental data fairly well. Among the blend compositions studied, Ziabicki’s kinetic crystallizability parameter was found to decrease with increasing PTT content. The effective energy barrier for non-isothermal crystallization process of these blends, analyzed based on the differential iso-conversional method of Friedman, was found to be an increasing function of the relative degree of melt conversion. Within the relative degree of melt conversion range of less than ca. 0.5, the effective energy barrier was found to increase with increasing PTT content.