Cure kinetics of a nadic methyl anhydride cured tertiary epoxy mixture

Abstract

Cure kinetics of a methyl nadic anhydride cured tertiary epoxy (i.e., Diglycidyl ether of bisphenol A, a tetrafunctional epoxy and a fluorine-containing diepoxy), which is potential matrix for a polyimide fiber reinforced composites, were studied using dynamic and isothermal differential scanning calorimeter scans. Results showed that addition of the tetrafunctional epoxy and fluorine-containing diepoxy has negligible effects on the underlying cure mechanisms. Variation of glass transition temperature with extent of cure can be fitted using DiBenedetto equation. The Kamal model coupled with an empirical diffusion factor can adequately model the isothermal cure data. The Kamal model can model the reaction data well before vitrification. However, after vitrification, obvious deviation from Kamal model was observed, which have to be corrected using a diffusion factor. The apparent activation energy obtained from the Kamal model using isothermal data, agrees with that from the advanced isoconversional method, which utilizes the dynamic cure data.