ISOTHERMAL CURE OF AN EPOXY CYCLOALIPHATIC AMINE SYSTEM - VITRIFICATION AND GELATION/

Times to gelation and times to vitrification during isothermal curing for the epoxy system diglycidyl ether of bisphenol A and 1,3-bisaminom ethylcyclohexane were measured at different curing temperatures betwee n 50 and 100 degrees C. Gelation occurs around 56% conversion. Vitrifi cation was determined from data curves of glass transition temperature , T-g, versus curing time obtained from DSC experiments. The minimum a nd maximum T,determined for this epoxy system were T-g0 = -37 degrees C and T-g infinity = 150 degrees C. Values of activation energy of the epoxy/amine cure reaction of 58kJ/mol and 49.5kJ/mol were obtained fr om T-g versus time shift factors and gel time measurements respectivel y. The isothermal time-temperature-transformation diagram has been est ablished.