Experimental and theoretical studies on the corrosion properties of some conducting polymer coatings

In this study, the effects of poly(N-ethylaniline) (PNEA) monolayer coating and PPY/PNEA and PNEA/PPY bilayer coatings, which were formed on the low carbon steel (LCS) surface by electropolymerization in 0.1 M monomer + 0.3 M oxalic acid medium, on the corrosion of the LCS in 1 M H₂SO₄ medium have been investigated. LCS electrodes, which were coated with each of these conductive polymer layers, were held in 1 M H₂SO₄ medium for various time periods, in order to obtain current potential curves, and with the help of these curves, the corrosion parameters have been determined. Experimental findings show that the LCS coated with polymer layers prevent the corrosion of bare LCS in 1 M H₂SO₄ medium and bilayer PPY/PNEA and PNEA/PPY coatings are better than monolayer PNEA coating. In order to elucidate the interaction between the coatings and the metal, theoretical calculations have been done using AM1 semiempirical method. The calculated data have been found to support experimental findings.