聚氨酯改性有机硅热分解反应动力学的研究

A STUDY ON THERMAL DEGRADATION REACTION KINETICS FOR POLYSILICONE MODIFIED WITH POLYURETHANE

以聚氨酯 (PUR)改性有机硅 ,用 TGA研究了改性体系的热分解行为 ,计算出了降解反应的反应级数、活化能及频率因子等动力学参数。结果表明 ,改性体系的热分解分两个明显不同的过程进行 ,两个过程有不同的动力学参数 ,并且改性体在它们中的失重比与体系中 PUR和有机硅的质量比也不相同。文中还分析探讨了改性体系的热分解反应机理 ,推断表明 ,较低温度下的热分解机理为受相界面控制的收缩圆柱体。

Thermal degradation of polysilicone modified with polyurethane(PUR) was investigated, and active energy( E ), reaction order( n ) and frequency factor( A ) were obtained by TGA. It is shown that there are two different degradation process for polysilicone PUR system. They have different kinetic parameter respectly and the ratio of loss of mass in two process is different from mass ratio between PUR and polysilicone in the PUR polysilicone system. It was also deduced that thermal degradation reaction mechanism is contracting cylinder controled by phase border.