The Use of Conducting Polyaniline as Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

Sulfonated chitosan (S-CTS) doped polyaniline (PANI) was synthesized by “template-free” method successfully, and it is reported as corrosion inhibitor for the first time. The corrosion inhibition property of PANI was demonstrated for mild steel in acidic environment using weight loss test, Tafel polarization, electrochemical impedance spectroscopy (EIS), scanning electronic microscope (SEM) and adsorption isotherm. The results revealed S-CTS doped PANI had excellent corrosion inhibition for mild steel in 0.5 M hydrochloric acid media and its inhibitive efficiency was more than 92.3% even with a low concentration of 40 mg/L.