Kinetics of 4,4 '-diaminodiphenylmethane curing of bisphenol-S epoxy resin

The kinetics of the cure reaction for a system of bisphenol-S epoxy resin ( BPSER), with 4,4'-diaminodiphenylmethane (DDM) as a curing agent, were stud ied by means of differential scanning calorimetry (DSC). Analysis of DSC da ta indicated that an autocatalytic behavior showed in the first stages of t he cure, with the model proposed by Kamal, which includes two rate constant s, k(1) and k(2), and two reaction orders, m and n. Rate constants k(1) and k(2) were observed to be greater when curing temperature increased. The ov er-all reaction order, m + n, is in the range of 2.5 similar to 3. The acti vation energies for k(1) and k(2) were 55 kJ/mol and 57 kJ/mol, respectivel y. Diffusion control is incorporated to describe the cure in the latter sta ges. (C) 1999 John Wiley & Sons, Inc.