Impact of polar groups concentration and free volume on water sorption in model epoxy free films and coatings

Two epoxy networks based on DGEBA resin and an amine hardener (TETA or DAMP) are tested. Thanks to a controlled curing protocol, two controlled macromolecular architectures are obtained. The network microstructure differs only in the crosslink density and the polar group number. Then, the free films are hygrothermally aged. Network microstructure impacts the solubility and the Arrhenius parameters associated to the water diffusion process. It appears that is principally governed by water-polar group interaction mechanisms.