Cas and water transport properties of epoxy-amine networks: Influence of crosslink density

The gas and water transport properties were studied on seven epoxy-amine ne tworks that differ by their di/mono epoxy composition and their cure cycle. The characteristic parameters of transport M-infinity and D were determine d in each case, and they show that the solubility and diffusion coefficient s are influenced by their composition. The solubility increases with the ex tend of cure and with the decrease of dangling chains, and in both cases th e evolution of the diffusivity is inverse. The variations of the solubility and diffusivity have been discussed as a function of two parameters: polar groups and unrelaxed holes of the glassy networks. (C) 2001 John Wiley & S ons, Inc.