Electrosynthesis of Poly(ortho-phenetidine) Coatings on Steel and Investigation of Their Corrosion Protection Properties

Abstract

Poly(ortho-phenetidine) coatings on 304 stainless steel (304 SS) surface have been synthesized by using the galvanostatic technique. The electrosynthesized coatings were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), UV-visible absorption spectrometry and Scanning Electron Microscopy (SEM). The anticorrosion performances of poly(ortho-phenetidine) coatings were examined in 0.1 M HCl medium by the electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technique. The corrosion rate of poly(ortho-phenetidine)-coated 304 SS was found ∼10 times lower than bare 304 SS and corrosion potential increased from –0.29 V for uncoated 304 SS to –0.19 V versus Ag/AgCl (3 M KCl) for poly(ortho-phenetidine)-coated 304 SS electrode. Electrochemical measurements indicate that poly(ortho-phenetidine) coating has good inhibiting properties with an efficiency of ~93% at 1.5 mA cm –2 applied current density in acidic corrosive media. The results of this study obviously ascertain that the poly(ortho-phenetidine) has an outstanding potential toprotect 304 SS against corrosion in an acidic environment.