Viscosity effect on epoxy–diamine/metal interphases

Used as adhesives, epoxy systems can originate, under specific conditions, thick interphases with metallic substrates. Indeed, by interaction with the metallic surface, the amine can be modified. So the adhesive nature changes by diffusion of this modified amine in the bonded joint . In this work, the effect of epoxy viscosity and curing process on the interphase formation is studied. Calorimetric and rheometric tests have been performed, which confirm the amine modification and emphasise the coexistence of two different networks in the adhesive. Also, the importance of the curing cycle in the interphases formation is shown.