水溶性封闭异氰酸酯单体的解封动力学

Deblocking Kinetics of Water-Solubility Blocked Isophorone Diisocyanate

采用热失重分析(TGA)法研究了水溶性封闭型异佛尔酮二异氰酸酯(IPDI)的热分解过程,利用傅里叶变换红外光谱法(FTIR)考察了谱图中40与140℃两种温度下的异氰酸酯特征峰.TGA与FTIR的结果表明失重阶段即对应封闭异氰酸酯的解封闭反应.用Friedman-Reich-Levi(FRL)和Flynn-Wall-Ozawa(FWO)两种动力学模型研究了解封反应的表观活化能E,所得平均表观活化能分别为125.0和124.5kJ·mol-1.采用双等双步法对解封过程进行表观机理函数判断,结果符合Jander方程,反应机理为三维扩散,结合FWO方程确定了反应级数n和指前因子对数lnA的范围.

The thermal decomposition process of water-solublity blocked isophorone diisocyanate（IPDI） was studied using thermal gravimetric analysis（TGA）.The characteristic peaks of isocyanante groups at 40 and 140 ℃ were observed by Fourier transform infrared spectroscopy（FTIR）.Results from TGA and FTIR showed that the degradation stage was a deblocking reaction of the blocked adduct.The Friedman-Reich-Levi（FRL） and Flynn-Wall-Ozawa（FWO） models were employed to investigate the apparent activation energies which were 125.0 and 124.5 kJ·mol-1,respectively.Based on the double equal-double step method,the reaction was analyzed by the apparent mechanism of the process of deblocking according to the Jander equation,which indicated that the reactive mechanism was a three-dimensional diffusion.The reaction order（n） and the logarithm of pre-exponential factor（lnA） were also determined using the FWO equation.