DETERMINATION OF THE ACTIVATION-ENERGIES FOR ALPHA-TRANSITION AND BETA-TRANSITION OF A SYSTEM CONTAINING A DIGLYCIDYL ETHER OF BISPHENOL-A (DGEBA) AND 1,3-BISAMINOMETHYLCYCLO-HEXANE (1,3-BAC)

Using dynamic mechanical analysis (DMA) we have studied the variation with the frequency of the dynamic mechanical properties (storage modul us, E'; loss modulus, E'' and loss tangent or tan delta) for a system containing a diglycidyl ether of bisphenol A (DGEBA) and 1,3-bisamino- methylcyclohexane (1,3-BAC). These properties were measured both in th e glass transition and beta transition regions. An increase in frequen cy caused a shift of tan 8 peak positions in both regions toward highe r temperature. Finally, we report the activation energies of a DGEBA/1 ,3-BAC epoxy system for alpha and beta transitions.