Corrosion Inhibition and Adsorption Properties of Mild Steel in 1 M Hydrochloric Acid Medium by Expired Ambroxol Drug

The inhibitive action of an examined expired Ambroxol (AB) drug on the corrosion of mild steel in 1 M hydrochloric acid medium has been studied by both weight loss and electrochemical techniques. The weight loss techniques result was discussed. The inhibition efficiency increases with increasing the concentration of the AB inhibitor. Electrochemical studies data support that examined expired AB drug is an efficient inhibitor for mild steel in 1 M hydrochloric acid medium. The adsorption of the examined drug obeys Langmuir’s and Temkin adsorption isotherm. Polarization studies indicate that this inhibitor acts as a mixed mode of inhibition. The various thermodynamic parameters were calculated and discussed. The protective film formed on the surface was confirmed by FTIR, SEM and EDS. The quantum-chemical calculation also supports the inhibitive effect of the inhibitors. The data collected from the studied techniques are in good agreement to confirm the ability of using expired Ambroxol (AB) drug as corrosion inhibitor for mild steel in 1 M hydrochloric acid medium.