Abstract
Expired declophen(2-(2, 6-dichloranilino) phenylacetic acid) ampoules were evaluated as non-toxic corrosion inhibitors for mild steel in 1 M HCl solutions, by chemical and electrochemical techniques, at different concentrations and temperature. The corrosion inhibition efficiency increased with increase in inhibitor concentration, but decreased with increase in temperature. Potentiodynamic polarization studies indicate that expired Declophen drugs acts as a mixed type inhibitor. The outcomes show that inhibition takes place by adsorption of the inhibitor on metal surface without altering the mechanism of corrosion process. The adsorption of Declophen takes place according to Langmuir's adsorption isotherm. Thermodynamic parameters were calculated and discoursed. The data collected from the studied techniques are in good agreement to confirm the ability of using expired Declophen ampoules as corrosion inhibitors for steel in hydrochloric acid corrosive medium.