异氰酸酯功能单体的封闭与解封闭

BLOCKING AND DEBLOCKING OF ISOCYANATE FUNCTIONALIZED MONOMER

用己内酰胺作封闭剂,研究了(3-异氰酸酯基-4-甲基)苯氨基甲酸-2-丙烯酯(TAI)功能单体的封闭和解封闭。用化学滴定法和傅里叶变换红外光谱表征封闭反应前后异氰酸酯基的变化情况,采用热失重分析确定封闭产物的解封闭温度。结果表明,封闭的最佳条件为:反应温度80℃,n(封闭剂):n(单体)=1.1:1,反应时间4～5 h,封闭率可达97%。解封闭反应起始温度为160℃,异氰酸酯解封闭速率最快时所对应的温度为200℃。

Allyl （3-isocyanate-4-tolyl） carbamate （TAI） was blocked by s-caprolactam. Chemical tion and FTIR were employed to characterize the isocyanate group content before and after bloc titraking. Thermal gravity analysis was used to determine the deblocking temperature of the blocked product. The results showed that the optimum blocking temperature and time is 80 ℃ and 4 - 5 h, respectively. The optimum mole ratio of e-caprolactam to TAI is 1.1 ： 1. The debl9cking temperature for initial and maximum rate is 160 ℃ and 200 ℃, respectively.