Evaluation of ecological organic paint coatings via electrochemical impedance spectroscopy

Abstract

The behaviour of five different water-based anticorrosive paint systems for the corrosion protection of carbon steel surfaces was evaluated by electrochemical impedance spectroscopy (EIS). Epoxy-polyamine, epoxy-amine and epoxy-acrylic resins as primer coats, and acrylic-polyurethane and acrylic paints as top coats, were investigated both in single layer and double-layer applications. The best protection was provided by the epoxy-amine resin, whereas acrylic-polyurethane exhibited the poorest characteristics and signs of corrosion could be observed since the initial moments of immersion onwards. The impedance spectra could be satisfactorily fitted by employing an equivalent circuit which corresponds to a porous barrier film.