Curing mechanism and kinetics of epoxy/anhydride system modified by benzoxazine

doi:10.3969/j.issn.0438-1157.2014.03.023

Abstract

Abstract: 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.

Key words: benzoxazine, epoxy resin, anhydride, curing mechanism, curing kinetics

摘要： 利用一种二胺型苯并(口恶)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(口恶)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。

关键词: 苯并(口恶)嗪, 环氧树脂, 酸酐, 固化机理, 固化反应动力学

CLC Number:

TQ320.2

LIAO Jinbin, JIANG Qibin, ZENG Zhi, LI Hongyan. Curing mechanism and kinetics of epoxy/anhydride system modified by benzoxazine[J]. CIESC Journal, 2014, 65(3): 929-933.

廖进彬, 姜其斌, 曾智, 李鸿岩. 苯并(口恶)嗪改性环氧酸酐体系的固化机理及动力学[J]. 化工学报, 2014, 65(3): 929-933.

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