Corrosion protection of steel by electropolymerized lignins

Electropolymerization of water soluble lignin derivatives (lignosulfonates) on steel surface is reported. It was noticed from both an appearance of anodic current of lignin oxidation and a subsequent considerable decrease in current at high anodic potentials, and confirmed by the knowledge of lignin oxidative polymerization. Ionic strength affects a potential of lignin oxidation: an increase of KCl concentration ten times (from 0.1 to 1 M) causes a decrease in oxidation potential for 1 V. Lignosulfonate electropolymerization is resulted in corrosion protection of carbon steel, which was more effective compared to the standard commercially available corrosion inhibitor COREXIT SXT-1003.