Abstract: | The curing behavior of epoxy resins was analyzed based on a simple kinetic model. We simulated the curing kinetics and found that it fits the experimental data well for both diglycidylether of bisphenol A–4,4′‐methylene dianiline and diglycidylether of bisphenol A–carboxyl‐terminated butadiene acrylonitrile–4,4′‐methylene dianiline systems. The kinetic results showed the curing of epoxy resins involves different reactive process and reaction stages, and the value of activation energy is dependent on the degree of conversion. By analyzing the effect of vitrification, at low curing temperature, we found the curing reaction at the later stage was practically diffusion‐controlled for unmodified resin, and the rubber component did not markedly decrease Tg at the early stage of reaction as would be expected. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2401–2408, 1999 |