Imidazole Derivatives as Corrosion Inhibitors for Zinc in Hydrochloric Acid

The efficiency of various imidazole derivatives as zinc corrosion inhibitors in hydrochloric acid (HCl) was investigated using electrochemical and gravimetric methods. A difference in efficiency (z) was observed with the introduction of different substituents into a imidazole skeleton. It was established that substituents which increased the electron density at the reaction center improved the corrosion inhibiting properties of the heterocyclic compound. A linear correlation between reaction kinetic data and the sum of the polar substituent constants was obtained.