Synergistic Effect of Halides Ions on the Corrosion Inhibition of Abelmoschus esculentus Seed Extract on Mild Steel in H2SO4

The inhibitive effect of Abelmoschus esculentus seed extract on the corrosion of mild steel in sulphuric acid was investigated using gravimetric, potentiodynamic and electrochemical impedance spectroscopy (EIS) techniques. The results obtained showed that Abelmoschus esculentus seed extract could serve as an effective inhibitor for the corrosion of mild steel in sulphuric acid. The percentage inhibition increased with increasing concentration of the extract at room temperature. Maximum inhibition efficiency of 90 % was obtained with 0.5 % v/v concentration. The inhibition efficiencies obtained from impedance and polarization measurements were in good agreement. Poteniodynamic polarization studies clearly revealed that the extract behave as mixed type inhibitor. The inhibition efficiency was significantly affected by the temperature of the medium. The synergism parameters (S) obtained was found to be greater than unity which indicates that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism.