Rheokinetic variations during curing of a tetrafunctional epoxy resin modified with two thermoplastics

The curing kinetics of an epoxy matrix based on tetraglycidyl diamino diphenyl methane polymerized with diamino diphenyl methane and those for its mixtures with poly(methyl methacrylate) and poly(ethersulfone) (PES) at compositions ranging from 0 to 15 wt.% were studied using differential scanning calorimetry in isothermal and dynamical conditions. Rheological properties were also measured to follow curing evolution. Apparent activation energies were calculated from the so obtained gelation times. Thermoplastic addition to the thermosetting resin delayed the polymerization, and above all in the PES case but it does not modify the cure kinetics of the thermosetting matrix. A modified autocatalytic kinetic model which contains the diffusional term was used. Satisfactory results were obtained as conversion curves fitted quite well the experimental data.