等温DSC法研究RFI用环氧树脂固化动力学

Curing kinetics of epoxy resin for RFI process using isothermal DSC

为了预测固化反应的进程,采用STA 449C型差示扫描量热仪,用等温DSC法研究了室温下成膜、中温固化的RFI工艺用(E-44/E-21(6/4,质量比))/GA-327=100/40(质量比)环氧树脂体系在80、90、100、110、120℃下的固化过程,通过Matlab数据拟合良好性统计法得到了n级固化模型、自催化模型及复合模型方程中的各个参数值。根据R2和离差平方和SSE确定了适合的动力学模型。研究表明:该树脂体系的固化反应具有自催化和扩散控制的特征,低温下受扩散控制的影响更大;该体系的固化反应动力学符合自催化反应动力学模型,其表观活化能Ea为56.7 kJ/mol,指前因子A为1.18×107s-1,固化反应的反应级数m、n分别为0.529和1.561。

To predict the curing behavior theoretically, the isothermal differential scanning calorimetry （DSC） method was used to investigate the curing process of a hybrid epoxy resin system for resin film infusion （RFI） at 80, 90, 100, 110 and 120℃, respectively. The curing system is composed of hybrid epoxy resin of E-44/E-21（6/4, mass ratio） with GA-327（GA-327/resin= 40//100, mass ratio） as curing agent, and a uniform film can be formed at room temperature and cured at 70-80℃. The corresponding parameters of the n-order curing model, the autocatalytic model and the Kamal model were determined by fitting the experimental data using Matlab software, respectively. According to the values of R^2 and the sum of square due to error （SSE） of the fitted data, a suitable curing reaction kinetic model was determined. It was found that the curing reaction of the hybrid epoxy resin system was of autocatalyzed and diffusion controlled characteristics, and the effect of the diffusion was much evident at a lower temperature. The data fitting results also indicate that the autocatalytic reaction kinetic model can be used to describe the cure kinetics of the curing system. The apparent activation energy Ea of the curing reactions is 56.7 kJ/ mol and the pre-exponential factor A of the system is l. 18× 10^7 s^-1. The cure reaction order m and n are 0. 529 and 1. 561, respectively.