Improved polyaniline coatings by in situ electropolymerization.

This paper is concerned with the in situ electropolymerization onto metal electrodes which is attracting increasing interest because of the wide range of possible applications revealed by the appropriate choice of monomers and electrolysis conditions. When the technique is aimed at the anticorrosion protection of a metal, coatings with high cohesion and strong adhesion to the substrate are required. These properties mainly confront penetration by water, oxygen and ions, and later polymer detachment due to underskin corrosion. In this respect the polyaniline and sulfur-bridged polyaniline coatings previously described were inadequate and therefore provided little protection. In the present note the authors describe how the use of monomers containing thermally curable groups may secure cohesion, whereas satisfactory adhesion may be achieved by adding nonionic surfactants of Triton type to the electrolytic solutions.