Diffusion control on the cure kinetics of DGEBA with ethylenediamines

The cure kinetics of DGEBA with aliphatic diamines was studied on the diffusion-controlled region. Two different diamines (ethylenediamine (EDA) and N-(methyl)ethylenediamine (MEDA)) were selected, to achieve different cross-linked networks. Additionally, reaction of DGEBA with butylamine was followed to compare non-cross-linked systems with the above mentioned ones. Curing temperatures were between 20 and 60 °C. Concentrations of epoxy and primary amine functionality were both followed by near FTIR, and Tg was analyzed by DSC. An autocatalytic model was applied. Diffusion control kinetic in cross-linked polymers was analyzed in terms of free volume decrease. In that region, a model based on a WLF equation provides a good fit to the experimental data.