Isothermal cold crystallization kinetics of polylactide/nucleating agents

The isothermal cold crystallization kinetics of polylactide (PLA)/nucleating agents (CaCP3, TiO2, and BaSO4, content from 0.5-2.0 wt %) was investigated by differential scanning calorimetry in the temperature range of 120-124 degrees C. With blending nucleating agents, the crystallinity of PLA had a maximum crystallinity of 14.9%. Crystallization rate decreased with increasing crystallization temperature in the researched content range. The crystallization rate followed the Avrami equation with the exponent n around 4.5. From Lauritzen-Hoffman equation, the nucleation parameter K-g was estimated. And from the value of K-g, regime 11 crystallization behavior can be concluded. Then the lateral and fold surface free energy were calculated from K-g. (c) 2007 Wiley Periodicals, Inc.