预测树脂基体材料性能与固化度关系的GIM模型

通过分析固化度对环氧树脂体系的自由度和结合能的影响，对GIM （Group interaction modelling）方法进行了拓展，研究了树脂材料性能随固化度的变化规律。以EPON862/DETDA体系为例，对拓展GIM方法进行了验证。研究结果表明，拓展GIM方法不仅可以准确预测完全交联EPON862/DETDA的材料性能，而且能预测非完全固化体系的玻璃化转变温度、体积收缩率、热膨胀系数及弹性模量随固化度的变化规律，以上结果均与实验和分子动力学模拟结果吻合较好。此拓展GIM方法可与固化反应动力学联合，为模拟环氧树脂在固化反应过程中产生的残余应力和变形提供准确的材料性能输入参数。 

GIM method for predicting the relation between material properties and conversion of epoxy resin

An extended GIM (group interaction modelling) method was developed by considering the influence of conversion on the cohesive energy and the degrees of freedom of epoxy resin system, which can predict the relation between conversion and material properties of epoxy resin. The epoxy resin composed of epoxy EPON862 and curing agent DETDA was used as an example for validation of the extended GIM method. It is found that the extended GIM method not only accurately predicts the material properties of fully cured EPON862/DETDA system, including glass transition temperature, volume shrinkage, coefficient of thermal expansion and elastic modulus, but also well captures the trend of these material properties changing with the conversion throughout curing process. And good agreement is found by comparing predicted results with that obtained from the molecular dynamics (MD) simulation and experiments. As combined with curing kinetics, this extended GIM method is capable of providing accurate material properties as the input parameters for modelling the shrinkage strain and residual stress throughout the curing process of epoxy resin.