Cure Kinetics of the Hydroxyl-Epoxide Reaction in DGEBA Epoxy Hardened with Diethanolamine

The curing of a diglycidyl ether of bisphenol-A Epoxy (Epon 828) with diethanolamine (DEA) involves a fast amine-epoxide reaction followed by a slower hydroxyl-epoxide reaction. At curing temperatures below 70$^{\circ}$C, the time scales of these two reactions are well separated. This permits the study of the hydroxyl addition as an ``isolated'' reaction. The reaction is strongly auto-catalyzed and is well fit to a modified form of the Kamal equation. Here we study the temperature dependence of the Kamal parameters with modulated differential scanning calorimetry and infrared spectroscopy.