Undoped polyaniline anticorrosive properties

Abstract

The anticorrosive properties of undoped polyaniline (PAni) casted onto mild- and galvanised steels were studied by a classical methodology used for organic coatings. Pure PAni, as well as, PAni plus an epoxy topcoat were tested in total immersion conditions monitored by electrochemical impedance. The influence of the substrate and the electrolyte composition were discussed. PAni performance was evaluated in terms of underfilm corrosion and adhesion loss in comparison with other coating systems. It was shown that undoped PAni did not have good barrier properties and adhesion to the substrates was very poor. Even with an epoxy topcoat, PAni coated samples had the worst performance in comparison with the other coating systems herein used as reference.