中文摘要：

通过热重分析研究了D，L-聚乳酸（PDLLA）在N2气氛中，不同升温速率条件下的热降解过程及其动力学行为。结果表明，PDLLA的主热降解过程为一级反应，当温度超过250℃即发生明显降解，同时分别利用Ozawa—Flynn—Wall、Friedman和Freeman—Carroll方法对其动力学参数进行了测定，得到PDLLA的热降解活化能值为97．78kJ／mol。

英文摘要：

At different heating rates, the thermal degradation process and kinetics of D, L-polylactic acid was studied in N2 through TG and DTG. Results showed that the main thermal degradation process is a first-order reaction and obvious decomposition will occur above 250℃. The parameters of thermal degradation kinetics of the D, L-polylactic acid have been obtained by Ozawa-Flynn-Wall, Friedman and Freeman-Car- roll methods and the reaction energies of D. L-polvlactic acid is 97.78kJ/mol.