The joint effect of amine and maleimide functional group in aminomaleimide on the curing kinetics and mechanical properties of epoxy resins

A new epoxy curing system, combining amine and maleimide functionality into a single molecule, was introduced to broaden current state of the art as regards epoxy, amine and maleimide systems. Curing agent aminomaleimide was tested in the curing process of several aromatic and aliphatic epoxies. Prepared mixtures in different weight (molar) ratios were investigated by nonisothermal differential scanning calorimetry to study and compare curing kinetics of different epoxies. The apparent activation energy was determined by Kissinger method, while Friedman method accompanied by Malek statistical approach was used in confirming the autocatalytic nature of epoxy curing and additional maleimide polymerization at the excess amount of aminomaleimide. Thermo-mechanical properties were determined by dynamic mechanical analysis and the effect of aminomaleimide curing agent compared to curing agent containing only amino functional groups was evaluated. Aminomaleimide showed improvement in the glass transition temperatures and higher char yields due to the involvement of maleimide moiety in the curing process. In overall, aminomaleimide showed the positive onemolecule joint effect of the amino group, behaving as an accelerator, and maleimide group, a mechanical properties enhancer.