Cure kinetics of epoxy resin and aromatic diamines

The kinetics of curing reaction of a diglycidyl ether of a bisphenol-A based epoxy (DGEBA) with 4,4'-diaminostillbene (DAS) and 4,4'-diaminoazobenzene (DAAB) as curing agents are studied by differential scanning calorimetery (DSC) using the isothermal technique. The experimental data show that the cure reaction is autocatalytic in nature, and all kinetic parameters of the curing reaction are determined using a semiempirical equation. The reaction of DGEBA with DAS is faster than that with DAAB under the same conditions and the activation energies of both systems are higher than those reported for other aromatic diamines. With increasing isothermal temperature and concentration of curing agents the rate constants are increased by the increasing of probability collisions between epoxide and primary amine groups while the activation energies remain constant. (C) 2004 Wiley Periodicals, Inc.