Electrochemical Evaluation of Anticorrosive Performance of Organic Acid Doped Polyaniline Based Coatings

In this work we examine the performance of the organic acid doped polyaniline to impart protection against corrosion when it is used as additive of long oil alkyd based red oxide primer paint. For this purpose, polyaniline doped with tartaric acid, oxalic acid and citric acid were characterized through FTIR and SEM studies. Cyclic voltammetry studies showed that doped polyaniline shown the electrochemical activity of the paints. Accelerated corrosion experiments (salt water chamber) revealed a significant improvement in the performance of the paint formulation which contained the aliphatic organic acid doped polyaniline coatings. These results were verified by evaluation of the electrical resistance and capacitance measurements of the films using electrochemical impedance spectroscopy. The results of this study reinforce the anticorrosive properties of long oil alkyd based red oxide primer paint through the formation of a protective layer of oxides using coatings which contain tartaric acid doped polyaniline.