快速拉挤用环氧树脂固化动力学及动态力学性能研究

Study on curing kinetics and dynamic mechanical properties of epoxy resin for rapid pultrusion

采用双酚A型和双酚F型缩水甘油醚,以甲基六氢苯酐为固化剂制备了耐热性好、强度高、适用期长的拉挤用增韧改性环氧树脂。由非等温差示扫描量热法(DSC)和动态热机械法(DMA)研究了树脂的固化反应及动态力学性能。利用Kissinger、Ozawa、Flynn-Wall--Ozawa法计算得到了反应活化能平均值为71.715 kJ/mol。采用多种机理函数进行拟合并筛选得到了固化过程最佳反应机理;由Sestak-Berggren自催化反应模型确定了相应的动力学参数(m=0.46,n=1.17,lnA=0.626),理论曲线与实验数据吻合良好。由DMA建立了CHILE(T_(g))模型,可预测不同固化度下树脂模量与温度的关系,为拉挤工艺确定及复合材料质量控制提供有效理论指导和依据。

A type of toughened epoxy resin with good heat resistance,high strength and long application period was prepared for pultrusion by using bisphenol-A and bisphenol-F epoxy resins as raw materials and methylhexahydrophthalic anhydride as curing agent,and its curing reaction and dynamic mechanical properties were studied through non-isothermal scanning calorimetry and dynamic mechanical analysis(DMA).The mean activation energy of the curing reaction was calculated to be 71.715 kJ/mol by using the Kissinger′s,Ozawa′s,and Flynn-Wall-Ozawa′s methods.The optimal reaction mechanism of the curing process was obtained through the fitting with several mechanism functions.The kinetic parameters,m,n,and lnA,were determined to be 0.46,1.17,and 0.626,respectively,by using the Sestak-Berggren autocatalytic reaction model.The theoretical curves were in good agreement with the experimental data.The calculated theoretical curves were in good agreement with the experimental data.The CHILE(T_(g))model established through DMA could well predict the relationship between the resin modulus and temperature under different curing degrees.This provides effective theoretical guidance and evidence for the determination of pultrusion process and quality control of composite materials.