Mechanistic kinetic model of an epoxy resin cured with a mixture of amines of different functionalities

The polymerization kinetics of a monoamine (p-toluidine), a diamine (4,4′-diaminodiphenylmethane) or a mixture of both amines reacted with an epoxy prepolymer, diglycidylether of bisphenol A (DGEBA), was analyzed using differential scanning calorimetry. A simple mechanistic model, consisting of an epoxy–hydroxyl complex formation out of equilibrium, including the possibility that amino hydrogens react with free epoxy groups or with the epoxy–hydroxyl complex, and taking into account the possible difference of the reactivity of amino hydrogens, provided a reasonable fitting of the whole set of experimental results with a lonely set of activation energies.