ELASTIC-MODULI AND ACTIVATION-ENERGIES FOR AN EPOXY M-XDA SYSTEM BY DMA AND DSC/

The influence of the resin/diamine ratio on the properties of the syst em diglycidyl ether of bisphenol A (BADGE n=0/m-xylylenediamine) (m-XD A) was studied. Variation of this ratio resulted in significant effect s on the cure kinetics and final dynamic mechanical properties of the product material. The study was made in terms of storage modulus (E'), loss modulus (E '') and molecular mass between cross-links (M-c) at d ifferent ratios. Two geometries (cylindrical and rectangular) were con sidered. The influence of temperature was studied through the activati on energy (E-a), which depends on the epoxy/amine ratio and the geomet ry of the samples. Glass transition temperatures (T-g) and glass trans ition temperatures for thermosets with null degree of conversion (T-go ) were determined by DSC. T-g decreases when amounts of curing agent g reatly in excess of the stoichiometric compositon were used.