THE INCORPORATION OF A CORROSION-INHIBITOR (2-BENZOTHIAZOLYLTHIOSUCCINIC ACID) IN POLYOXYPHENYLENE COATINGS PREPARED BY IN-SITU ELECTROPOLYMERIZATION

Polyoxyphenylene coatings have been obtained on mild steel by in situ electropolymerization of phenol/2-allylphenol mixtures in the presence of 2-benzothiazolylthiosuccinic acid (MBTS), a corrosion inhibitor of Fe. MBTS interferes only slightly with the electropolymerization proc ess and is incorporated in the coating at concentrations slightly high er than its concentrations in the electrolytic solutions. Accelerated corrosion tests (a.c. impedance) have shown that a 1.5% MBTS content m arkedly enhances the corrosion resistance properties of coated samples exposed to 3% NaCl solutions. MBTS was also tested as an inhibitor fo r bare mild steel exposed to NaCl solutions of variable concentration; it was found that the inhibitor acts mainly on the anodic process and that its effectiveness degrades as the NaCl concentration increases.