聚己内酯热分解机制及其热分解产物

Thermal Degradation Mechanism and Pyrolysis of thePolycaprolactone

精制后的聚己内酯用三氯甲烷为溶剂制成溶剂膜。以调制式热重分析（TGA）为聚己内酯热裂解的研究方法,并使用核磁共振（NMR）和傅里叶变换红外光谱（FTIR）分析其热裂解后所得的产物。TGA的结果表明,聚己内酯的热裂解过程分为两步,第一步的分解温度为205~295℃,失重率为7.0%;第二步分解温度为311~374℃,失重率为88%,结果同时得到了聚己内酯热分解的活化能、指前因子和速率比等热分解动力学常数,分别为第一步80kJ/mol,5min-1和0.3,第二步分别为146kJ/mol,11min-1和0.47。裂解后的产物经过NMR和FTIR分析,发现不但有高分子的聚己内酯,也有呋喃、取代环丙烷以及不饱和的羧酸等小分子化合物产生。

The Polycaprolactone（PCL） cast film was made using purified PCL,the purified CHCl3 acted as solvent.The specimen was investigated by using modulated thermogravimetry analysis,the structure of low molecular compounds were determined by NMR and FTIR.It can be found from results of modulated TGA that the PCL pyrolysis had two steps,the decomposition temperature and the weight loss rate in the first step were 205~295℃ and 7.0% respectively,while in the second were 311~374℃ and 88%.At the same time the Ea,Z and ln[rate ratio] be got,in the first step the results were respectively 80kJ/mol,5min-1 and 0.3,as in the second were 146kJ/mol,11min-1 and 0.47.And the result of the NMR and FTIR suggested that during the pyrolysis process,not only be get macromoleclar PCL,but also the furan,cyclopropanes displaced unsaturation carboxylic acid were produced.