动态扭振法对HTPB/TDI体系固化过程的研究

Curing Behaviors of HTPB/TDI System via Dynamic Torsional Vibration Method

采用动态扭振法研究HTPB/TDI体系的固化过程,获得体系在80,90,100,110℃下时扭矩随固化时间变化关系,发现HTPB/TDI的固化过程分为3个阶段:第1个阶段为液态到凝胶点阶段;第2阶段为凝胶点到高弹态阶段;第3阶段为硬化点到固化终点阶段.根据Flory凝胶化理论计算得到HTPB/TDI体系在TPB催化时固化反应活化能为1.58kJ/mol,与傅里叶变温红外法根据Arrhenius公式求得的41.98kJ/mol基本一致.通过ATR漫反射红外对HTPB/TDI胶片进行氢键分析,证实的确发生动态扭振法所得到的固化第3阶段.

A dynamic torsional vibration method was applied to on-line monitor the curing behaviour of hydroxyl-terminated polybutadiene/toluene diisocyanate(HTPB/TDI)system at different temperature.According to the diagram of torque change with time,the curing process was divided into three phases:the first phase was the period from liquid stage to the gel point;the second phase was the period from the gel point to the hardening point;the third phase was the period from the hardening point to the curing end-point.During the third stage the internal chemical cross-linking basically completed while the physical cross-linking point still forming.Therefore,the value of torque was growing slowly till the curing end-point.According to the Flory gelation theory,the calculated △Ea of HTPB/TDI system is41.58kJ/mol,almost the same result calculated with the FT-IR method.FT-TR method can only reflect the first and the second period of the curing process.And the dynamic torsional vibration method can monitor full-range of the curing process.The infrared diffuse reflectance spectroscopy of HTPB/TDI system validates the dynamic torsional vibration method.