Abstract
This study examines the use of poly(o-toluidine) (POT) coatings for the corrosion protection of type- 304 austenitic stainless steel (SS) in natural seawater. The POT coating was synthesized on the SS substrates from an aqueous solution of H2SO4under galvanostatic conditions using various current densities. The resulting POT coating was uniform, shiny and strongly adherent to the steel substrates. The polymer coating was characterized by UV-visible absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The ability of POT to serve as a corrosion-protective coating for stainless steel was examined by measuring the change in the open-circuit potential (Eocp) overtime, the potentiodynamic polarization, and the results of electrochemical impedance spectroscopy (EIS). The results of this study clearly show that the POT prepared with the lowest current density provides the best protection against corrosion in a natural seawater environment.