Non‐isothermal crystallization kinetics and spherulitic morphology of nucleated poly(lactic acid): effect of dilithium cis‐4‐cyclohexene‐1,2‐dicarboxylate as a novel and efficient nucleating agent

The effect of dilithium cis‐4‐cyclohexene‐1,2‐dicarboxylate (CHDA‐Li) as a novel and efficient nucleating agent on the crystallization behaviors and spherulitic morphology of poly(lactic acid) (PLA) as well as non‐isothermal crystallization kinetics of the nucleated PLA was studied by means of differential scanning calorimetry and polarized light microscopy. The results show that CHDA‐Li serves as a good nucleating agent to accelerate the crystallization rate of PLA. The nucleation ability of CHDA‐Li is superior to octamethylenedicarboxylic dibenzoylhydrazide. With the incorporation of CHDA‐Li, the number of the spherulites increases, and the size decreases significantly. The non‐isothermal crystallization kinetics of the nucleated PLA can be well described by Jeziorny's and Mo's models. The activation energies (ΔE) of non‐isothermal crystallization were calculated by Kissinger's and Friedman's methods. The crystallization rate of PLA/0.5 wt% CHDA‐Li sample is faster than that of PLA/0.2 wt% CHDA‐Li sample, while the ΔE of the former is lower than that of the latter. Copyright © 2015 John Wiley & Sons, Ltd.