A dsc kinetic study on the effect of filler concentration on crosslinking of diglycidylether of bisphenol-A with 4,4'-diaminodiphenyl methane

The kinetics of formation of epoxy resin composites was studied using an epoxy matrix of diglycidylether of bisphenol-A (DGEBA) and 4,4'-diaminodiphenylmethane (DDM) as curing agent in the presence of quartz flour as filler. The curing reactions of these systems were kinetically followed by differential scanning calorimetry (d.s.c.) at different scanning rates. The activation energies of the curing reactions were obtained using non-isothermal methods: the single scanning rate method of Barrett as well as the multiple scanning rate methods of Kissinger, Osawa and half-width. The crosslinking process is characterized by an average activation energy of 54.2-62.7 kJ mol(-1) despite different methods or filler concentrations being used to obtain it. The reaction rate for the systems with filler concentrations higher than 10 wt% showed a considerable decreasing at higher temperatures at conversions higher than 50%. (C) 1997 Elsevier Science Ltd.