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.