Electrosynthesis, Characterization and Corrosion Inhibition Study of DBSA-Doped Polyaniline Coating on 310 Stainless Steel

The synthesis of polyaniline doped with dodecylbenzene sulphonic acid (Pani-DBSA) coatings on 310 stainless steel (310 SS) surfaces has been investigated by using the galvanostatic method. The synthesized coatings were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), UV-Visible absorption spectrometry and Scanning Electron Microscopy (SEM). The anticorrosion performances of Pani-DBSA coatings were investigated in 5% NaCl solution by the potentiodynamic polarization technique and Electrochemical Impedance Spectroscopy (EIS). The corrosion rate of Pani-DBSA coated 310 SS was found ∼30 times lower than bare 310 SS and potential corrosion increased from -0.84 V versus Ag/AgCl for uncoated 310 SS to -0.71 V versus Ag/AgCl for Pani-DBSA coated 310 SS electrodes. Electrochemical measurements indicate that Pani-DBSA coated have good inhibiting properties with a mean efficiency of ~96% at 5 mA cm-2 current density applied to 310 SS corrosion in chloride media. The results of this study clearly ascertain that the Pani-DBSA has an outstanding potential to protect 310 SS against corrosion in a chloride environment.