采用热重法研究了聚乳酸在空气中的热分解过程，升温速率分别为5，10，15，20，30 K/min，温度范围为室温～1250 K，并利用TGA曲线分析了聚乳酸的热降解特点。结果表明，热分解反应最剧烈的温度介于550～660 K之间，热分解动力学分析表明，该热分解过程为一级反应。热分解反应的活化能和频率因子可以通过动力学模型加以估算。

Thermogravimetric analysis (TGA) was applied to investigate the thermal decomposition behavior of poly lactic acid in air with heating rates of 5, 10, 15, 20, 30 K/min and from ambient temperature up to 1250 K. The thermal decomposition features were obtained from resultant TGA curves. The results showed the main thermal decomposition was in the temperature range of 550~660 K and it was found to be the first order reaction from kinetic analysis. Activation energy and frequency factor for thermal decomposition can be estimated by using certain kinetic models.