Corrosion inhibition behavior of new synthesized nonionic surfactants based on amino acid on carbon steel in acid media

Three structurally different amino acids (Leucine, phenyl alanine and methionine) were reacted with oleic acid and polyethylene glycol (600) to give three nonionic surfactants (S-1, S-2 and S-3). The chemical structures of the prepared surfactants were confirmed by FT-IR and H-1, (CNMR)-C-13. The surface parameters were calculated by surface tension measurements. The inhibition efficiencies of the prepared inhibitors on carbon steel in 1 M HCl were studied using polarization, and electrochemical impedance spectroscopy. Correlation between the quantum chemical calculations and inhibition efficiency was discussed. From the obtained results, the inhibitor based on L-phenyl alanine has high efficiency (94.14% at 1 x 10(-3) mol L-1) more than the other inhibitors. (C) 2016 Elsevier B.V. All rights reserved.