β-Enaminoesters as Novel Corrosion Inhibitors for Carbon Steel in Acidic Medium

In this work, two β-enaminoesters, EN1 and EN2, were synthesized, characterized and their anticorrosion effects on American Iron and Steel Institute (AISI) 1020 carbon steel in 0.5 mol L-1 HCl were investigated using gravimetric and electrochemical methods. The results revealed that both compounds inhibit corrosion. Good correlations were observed between results obtained for gravimetric and electrochemical methods. EN1 exhibited highest efficiency of 98% after 24 h of immersion in HCl solution. The adsorption of compounds on steel surface followed the modified Langmuir adsorption isotherm. Surface morphology of carbon steel was examined using scanning electron microscopy showing that the metal surface was protected by EN1 as inhibitor of corrosion.