Utilization of sulfidated poly (acrylamide-vinyl acetate) as a new corrosion inhibitor for carbon steel in acidic media

Abstract

This paper study the utilization of sulfidated poly (acrylamide-vinyl acetate) (SG), which is previously prepared by the expose of poly (acrylamide-vinyl acetate) copolymer (AG) to H2S gas (15ppm), as a new corrosion inhibitor for carbon steel in acidic media. The corrosion inhibition efficiency of these inhibitors is detected in carbon steel surface in 1M HCl solution by the weight loss and electrochemical techniques. Untreated and treated steel surfaces were examined by scanning electron microscopy (SEM). The obtained results show that the maximum inhibition efficiency (ηp) by SG inhibitor in 1M HCl solution at 500ppm and 303K was 96.71%. Also, the potentiodynamic polarization curves indicated that the investigated inhibitors behave as a mixed type inhibitor. Adsorption of these inhibitors on the carbon steel surface was found to obey Langmuir's adsorption isotherm. Both of the computed quantum chemical properties viz., electron affinity (EA), highest occupied molecular orbital (EHOMO), the lowest unoccupied molecular orbital (ELUMO), energy gap ΔE=EHOMO–ELUMO, dipole moment (μ), logP and ΔN showed good correlation with experimental inhibition efficiency.