Application of multilayered particles formed by poly(3,4-ethylenedioxythiophene) and poly(N-methylpyrrole) as anti-corrosive additives of conventional organic coatings

Multilayered systems containing 3 or 5 layers of poly(3,4-ethylenedioxythiophene) and poly(N-methylpyrrole) have been prepared using a layer-by-layer electrodeposition technique. These multilayered systems have been found to present very high electroactivities suggesting that their performance as anti-corrosive additive of conventional organic coatings (paints) could be even better than that of single-component conducting polymers. The performance of the prepared multilayered systems as anti-corrosive additives of epoxy paints has been checked. For this purpose, accelerated corrosion tests were performed using an aggressive solution medium. Analysis of the corroded area indicates that the addition of a low concentration (0.2% w/w) of these multilayered systems to the paint formulation enhances significantly the corrosion protection imparted by the coating.