Corrosion protection of galvanized iron by polyaniline containing wash primer coating

Wash primer treatment of galvanized iron (GI) structure is widely used before painting in order to improve adhesion. Traditional wash primer contains zinc tetroxy chromate. Due to hazardous nature of chromate, alternate compounds for chromate replacements have been identified. In recent years polyaniline containing coating has been found to protect GI. In this study, a wash primer based on polyaniline has been formulated and its corrosion protection ability of GI has been compared with that of traditional chromate based wash primer by salt spray and EIS test. It has been found that the polyaniline based wash primer is able to protect GI and its corrosion protection performance is similar to chromate based wash primer coating.