Influence of cure conditions on barrier properties and interface of epoxy coatings

Epoxy resins are often used as barrier coatings to ship liquid cargoes. To eliminate failures from pinhole defects in a single coating layer, a two-layer coat is used. The curing extent of the first layer before the second layer is applied dictates the coating's solvent barrier performance. The interlayer adhesion depends on the ability of the first layer to react with the second. Consequently the interface of the partially cured layer is of great importance. We will use NR to study spin-cast epoxy resin coatings that have experienced a range of controlled curing conditions against perdeuterated solvents. These experiments will characterise the extent to which solvent can penetrate the partially cured epoxy as well as the detail of the composition profile at the interface. Crucially, NR can also measure solvent accumulation at the interface between layers in a two-layer coating.