Corrosion Inhibition of Zinc in HCI Solution by Several Pyrazole Derivatives

Abstract

The corrosion inhibition of zinc in HCI solutions by several pyrazole derivatives-namely, 3(5) amino, 5(3) phenylpyrazole; 3(5) amino, 5(3) [4'-methylphenyl] pyrazole; 3(5) amino, 5(3) [4'-methoxyphenyl] pyrazole; and 3(5) amino, [4'-chlorophenyl] pyrazole-was studied by capacitance and polarization measurements. Their efficiencies are 77%, 85%, 87.8%, and 89%, respectively. They act as anodic inhibitors through their adsorption on the electrode surface by their active centers without a significant change in the mechanism of the anodic dissolution process. The adsorption process of the additives was observed to obey Temkin isotherm.