"N,N-Bis(phosphonomethyl) Glycine, Zn 2+ and Tartrate" -A New Ternary Inhibitor Formulation for Corrosion Control of Carbon Steel

Abstract

Abstract Studies on inhibition of corrosion of carbon steel in aqueous environment using N,N -Bis(phosphonomethyl) glycine (BPM G), zinc ions and tartrate are presented. The investigations revealed that tartrate acts as an excellent synergist in corrosion inhibition. Optimu m concentrations of all the three co mponents of the ternary formu lation are established by gravimetric studies. Potentiodynamic polarization studies indicate that the new ternary system is a mixed inhib itor. Results of the impedance studies show that a protective film is formed on the metal surface in presence of the inhibitor formu lation. Analysis of the protective film us ing X-ray photoelectron spectroscopy (XPS) and reflect ion absorption Fourier transform infrared (FTIR) spectroscopy infer the presence of Zn(OH) 2 , o xides and hydroxides of iron and the inhibitor mo lecules in the surface film probably in the form of a co mplex, [Zn(II)-BPM G-tartrate]. A plausible mechanism o f corrosion inhibit ion is proposed