Non-isothermal crystallization kinetics and spherulitic morphology of nucleated poly(lactic acid): Effect of dilithium hexahydrophthalate as a novel nucleating agent

Abstract

The effect of dilithium hexahydrophthalate (HHPA-Li) as a novel and efficient nucleating agent on the non-isothermal crystallization behaviors and spherulitic morphology of poly(lactic acid) (PLA) was studied. Jeziorny’s, Ozawa’s and Mo’s models were employed to describe the non-isothermal crystallization kinetics of the nucleated PLA samples. The activation energies (ΔE) of non-isothermal crystallization were calculated by Friedman formula. The results showed that Jeziorny’s and Mo’s methods well described the non-isothermal crystallization kinetics of the nucleated PLA samples, while Ozawa’s model failed. The crystallization rate of PLA/0.5wt% HHPA-Li sample was faster than that of PLA/0.2wt% HHPA-Li sample, while ΔE of the former was lower than that of the latter. It was also found that the presence of HHPA-Li significantly increased the number and decreased the size of spherulites.