Electroactive Sulfonated Polysulfone Polymer as Corrosion Inhibitor for Mild Steel in Acidic Medium

The corrosion of mild steel in HCl medium containing different concentrations of sulfonated polysulfone polymer (SPS) has been evaluated by electrochemical, chemical and theoretical studies. SPS shows around 84% inhibition efficiency at 3000 ppm concentration. Inhibition efficiency increases with increase in temperature from 30 to 60 °C. The adsorption of SPS on mild steel was found to be Langmuir’s adsorption isotherm. The calculated thermodynamic functions were employed to give further insight into the mechanism of inhibition action of SPS. Quantum chemical calculations were supported the results. Dipole moment of SPS was found to be 4.6 D, ΔE (energy difference) was 5.02, and these values suggest the good interaction between inhibitor and mild steel surface. Scanning electron microscopy images confirm the adsorbed inhibitor film on the metal surface. FTIR results validate the interaction of SPS with mild steel surface. © 2017, Springer International Publishing AG.