EFFECT OF CURE TEMPERATURE ON THE STRUCTURE AND WATER-ABSORPTION OF EPOXY AMINE THERMOSETS/

Dielectric and rheological measurements are reported on the effect of cure temperature on the water absorption of tris[(2,3-epoxypropoxy)phe nyl] methane cured with a 1:1 stoichiometric ratio of 4,4'-diaminodiph enylsulphone. Analysis of the water absorption characteristics of thes e materials using a combination of dielectric and gravimetric measurem ents has indicated that water molecules can be found in two distinctly different types of environments. There are water molecules which are strongly interacting with polar groups and water molecules clustered t ogether into sub-micro-scale cavities within the matrix structure. Cha nges in the final cure temperature have the effect of changing both th e extent and distribution of the types of water molecules present in t he matrix. Validation of the diffusion coefficients obtained from the dielectric analysis is based on a comparison with gravimetric data and the implications are discussed. Differences observed between these tw o different types of measurement are related to peculiarity in the die lectric method and its extreme sensitivity to interfacial phenomena.