苯并嗪改性环氧酸酐体系的固化机理及动力学

摘要

An epoxy/anhydride system was modified by aromatic diamine-based benzoxazine. The curing mechanism of the system was analyzed with Fourier transform infrared spectroscopy(FT-IR)and differential scanning calorimetry (DSC). The blend system exhibited two curing reactions in the curing process. Epoxy resin first cured with sufficient anhydride catalyzed by imidazole at 100℃, and cured completely at 150℃ for 2 h. Benzoxazine underwent ring-opening polymerization at 180℃. The curing kinetics of modified resin system was studied with non-isothermal DSC at different heating rates. The average activation energies of two reactions were calculated utilizing the Flynn-Wall-Ozawa method to be 65.27 kJ·mol-1 and 92.8 kJ·mol-1, respectively. Both curing reactions were found to be autocatalytic processes by the Friedman method, and the predicted curves from the autocatalytic model fitted well with those of experiments.%利用一种二胺型苯并嗪改性环氧酸酐体系。通过FT-IR和DSC分析了改性体系的固化机理。结果表明：共混树脂体系在固化时存在两个反应，首先是环氧树脂与足量的酸酐在咪唑作用下在100℃先开始固化，并在150℃固化2 h后固化完全，之后苯并嗪在180℃发生开环聚合。用非等温DSC法研究了该共混体系的固化动力学。采用 Flynn-Wall-Ozawa 方法求出了共混体系在固化时两个固化反应的活化能，分别为65.27 kJ·mol-1和92.8 kJ·mol-1，并利用Friedman方法判断了两个反应都是自催化反应，计算得到自催化模型曲线与实验曲线能较好地吻合。