侧基含磷共聚酯的热降解动力学及热稳定性

采用不同的升温速率,用Kissinger法研究了聚酯(PET)和侧基含磷共聚酯(FR-PET)在氮气气氛中热降解动力学,采用时-温等效原理对其热稳定性进行了深入研究,等温热失重法和Kissinger法将寿命方程及动力学参数联系起来,确定了它们之间的关系。结果表明,阻燃剂的引入降低了PET整个热降解过程的平均活化能,并改变了反应级数,但使PET的热稳定性有所提高。两种方法所确定的寿命方程较为接近,Kissinger法更为简便、迅速,为材料寿命的预测提供了捷径。

The Thermal Degradation Kinetics and Thermal Stability of Copolyester Containing Phosphorus Linked Pendant Groups

By using of TG and DTG,the thermal stability and thermal degradation kinetics of poly(ethylene terephthalate)(PET) and flame retardant copolyester(FR-PET) containing phosphorus linked pendant groups were investigated under highly purity N2 at different heating rates between 10 and 40 ℃/min.The relation between kinetics parameters and life equations was discussed according to isothermal thermogravimetric curves.The parameters of the thermal degradation kinetics of PET and FR-PET were obtained by Kissinger equation.The results clearly demonstrate that the incorporation of phosphorus-containing unit slightly improves thermal stability of PET,and decreases the average activation energy of PET.The activation energy for PET and FR-PET is 224 kJ/mol,213 kJ/mol,the reaction orders are 1.5,1.05,respectively.The life equations determined by the isothermal thermogravimetric technique and Kissinger method are very close.In comparison with two methods,Kissinger method is more excellent than isothermal thermogravimetric technique,which implies that it is a useful means for practical application in lifetime assessment.