Thermal Decomposition Kinetics of Poly(L-lactic acid) after HeatTreatment

Thermal decomposition behavior of Poly(L-lactic acid) (PLLA) and PLLA composites after different heat treatment were investigated using thermogravimetric analysis. Firstly, the thermal decomposition results of neat PLLA showed that the decomposition of PLLA was a first-order kinetic reaction, and thermal decomposition kinetics indicated that the heat treatment significantly affected activation energy of thermal decomposition of PLLA. The measurement results also exhibited that the onset decomposition temperature of PLLA treated below 115 oC was lower than that of the pristine PLLA. Then, the effect of additive CaCO 3 on the thermal decomposition behavior of PLLA was evaluated. The addition of CaCO 3 could significantly improve the crystallization performance of PLLA, but the CaCO 3 did not change the decomposition trend of PLLA, and the thermal decomposition behavior of PLLA/CaCO 3 composites after isothermal heat treatment was similar to that of PLLA. However, the thermal decomposition activation energy of PLLA/CaCO 3 is lower than that of PLLA.