原位与离位FTIR法研究环氧树脂固化动力学

摘要

采用原位及离位傅里叶变换红外光谱(FTIR)法研究了固化剂为4,4'-二氨基二苯砜(DDS)的环氧树脂(E51)体系的固化动力学.结果表明,固化反应开始时,环氧基转化率在较短时间内达到较高水平；随时间的延长,环氧基转化率逐渐变慢.根据动力学方程求得反应级数为1.999,得出该反应是二级反应.比较原位法与离位法固化曲线得出,原位法在时间轴上是准确的,离位法在温度轴上是准确的.依据求得的反应活化能和反应常数确立了该固化体系的固化时间、温度及环氧基转化率的关系方程,得出该体系的最佳固化条件为170℃、7h.%The curing kinetics processes of epoxy resin (E51) systems with curing agents of DDS were researched by in-situ and ex-situ FTIR methods. The results demonstrate that the conversion rate of epoxy group is rapidly increased in the initial curing reaction, the conversion and reaction rate are decreased gradually with the time increasing. The reaction order is computed as 1. 999 by dynamic equations, and it is second order reaction. The comparison between in-situ and exsitu method shows that the in-situ FTIR is better in time and the ex-situ FTIR is better in temperature for studying the epoxy resin curing dynamics. The relation equation between curing time, temperature and conversion rate of epoxy group is established by the activation energy and reaction constant, and the best curing condition is 170℃ and 7 hours for this epoxy resin system.