Studies on corrosion resistant properties of sacrificial primed IPN coating systems in comparison with epoxy–PU systems

The continuous development in the field of protective coatings and the search for newer materials with improved properties have led to the emergence of interpenetrating polymer networks (IPNs) as binders for high performance organic coatings for corrosion protection. In this study, one such ambient curing IPN polymer alloy poly(epoxy–urethane–acrylate) developed specially for use in protective coatings has been studied. Undercoat and a topcoat based on the alloy have been formulated and coated over zinc ethyl silicate primed steel surfaces. Similar formulations based on an epoxy polyamide undercoat and a PU topcoat has been formulated and coated over zinc ethyl silicate primed steel surfaces. Both the systems were evaluated for their physical and corrosion resistant properties by subjecting them to accelerated laboratory tests and field test at a corrosive location. The results are reported and conclusions drawn in this paper.