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

The curing kinetics of an epoxy matrix based on tetraglycidyl diamino diphe nyl methane polymerized with diamino diphenyl methane and those fur its mix tures with poly(methyl methacrylate) and poly(ethersulfone) (PES) at compos itions ranging from 0 to 15 wt.% were studied using differential scanning c alorimetry in isothermal and dynamical conditions. Rheological properties w ere 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 mat rix. A modified autocatalytic kinetic model which contains the diffusional term was used. Satisfactory results were obtained as conversion curves fitt ed quite well the experimental data. (C) 2001 Elsevier Science Ltd, All rig hts reserved.