Ethoxylated fatty acids as inhibitors for the corrosion of zinc in acid media

The inhibition effect of ethoxylated fatty acids were used as inhibitors for the corrosion of zinc metal in 1.0 M hydrochloric and 1.0 M sulfuric acid solutions at various temperatures ranging from 25 to 55 °C is investigated by weight loss measurement and electrochemical methods. The protection efficiency depends upon the type and concentration of the inhibitor and the nature of the acid medium. In both acid solutions the protection efficiencies of the inhibitors decrease with the increase in temperature. The inhibition was assumed to occur via the adsorption of the fatty acid molecules on the metal surface. The thermodynamic functions of dissolution and adsorption processes were calculated and discussed.