Electrochemical synthesis and corrosion inhibition performance of poly-5-aminoindole on stainless steel

Poly-5-aminoindole (P5AIn) was coated by potentiodynamic methods onto type-304 stainless steel (SS) using a 0.3 M oxalic acid solution containing 0.05 M 5-aminoindole (5AIn) monomer. The corrosion protection ability of the polymer coating was studied using open circuit potential (Eocp)-time measurements, polarization curves, and electrochemical impedance spectroscopy (EIS) after the electrodes had been immersed in a 3.5% NaCl solution as the corrosive media. We used scanning electron microscopy (SEM) to examine the electrode surface characteristics. The results indicated that the polymer film adhered to the stainless steel surface and inhibited the SS corrosion for the 96-h immersion period.