Effect of urethanes on base-catalyzed epoxy reaction

The effect of carbamate (urethane) groups on the curing reaction of an epoxy catalyzed by tertiary amine was studied by infrared (IR) and differential scanning calorimetry (DSC) analysis. It was found that the aromatic-connected carbamate (Ar-carbamate) accelerated the consumption rate of epoxy in the epoxy/tertiary amine/Ar-carbamate reaction system, where the tertiary amine and Ar-carbamate was found to form an active complex with stoichiometric ratio in the curing reaction. However, under the introduction of aliphatic-connected carbamate (Al-carbamate) into the reaction system, no complex formed with the tertiary amine during the reaction and therefore no acceleration in the reaction rate was observed.