摘要
采用傅立叶变换红外光谱仪 (FTIR)法“原位”跟踪了二胺扩链剂 2 ,4 / 2 ,6 二氨基 3,5 二甲硫基甲苯 (DMTDA)与异氰酸酯扩链反应的过程。实验结果表明 ,本体聚合反应中 ,在反应初期低转化率时 ,反应规律表现为良好的二级动力学关系 ,给出了反应初期的动力学常数。反应后期高转化率时 ,反应速率常数受温度影响较大。当温度较低时 ,反应受扩散控制影响 ,NCO和NH2 反应的二级反应动力学速率常数逐渐变小 ;温度较高时 ,反应速率常数变大 ;DMTDA的本体聚合反应时活化能Ea 为 2 6 .3kJ/mol。 10 0℃下DMTDA的反应初期的速率常数为 3.7× 10 - 3kg/mol·s ,其活性是MOCA的 3.7倍。
The kinetic studies for the curing reaction of PUU extended by aromatic diamine DMTDA were studied by using In-Situ quantitative FTIR. It showed that the reactions followed 2nd-order kinetics at low conversion. Under the condition of high conversion, the 2nd-order rate constants at low temperature decreased with increasing reaction extent, due to the influence of diffusion control, however, they increased with increasing reaction extent at high temperature. The E_a of the bulk reaction of NCO with NH_2 is 26.3 kJ/mol. The rate constants at the low conversion for DMTDA was 3.7×10^(-3) kg/mol·s, and its reactivity was about 3.7 times that of the MOCA, and the comparision of the relative reactivity for common diamine extender was given.
出处
《聚氨酯工业》
2004年第3期18-21,共4页
Polyurethane Industry
基金
石油大学国家重点实验室开放基金 (2 0 0 3- 0 4 )
教育部留学归国基金 (2 0 0 3- 4 0 6 )
