Synthesis, Characterization and Inhibition Effect of a New Schiff Base (E)-3-(((2-amino-4-methylphenyl)imino)methyl) naphthalen-2-ol on the Corrosion of Carbon Steel X48 in acidic medium

Abstract

In the present investigation a new Schiff base named (E)-3-(((2-amino-4-methylphenyl)imino) methyl)naphthalen-2-ol (L) was synthesized, characterized, and tested as a corrosion inhibitor for Carbon steel X48 in two medium 1 M HCl and 0.5 M H2SO4, the corrosion efficiency coefficient was evaluated using weight loss method, Tafel polarization and electrochemical impedance spectroscopy. The experimental results suggest that this compound is an efficient corrosion inhibitor in both acidic media, and the inhibition efficiency increases with the increase of inhibitor concentration. Inhibitor adsorption on the Carbon steel X48 surface follows Langmuir isotherm. Thermodynamic parameters such as Ea, ΔH0a, ΔS0a, ΔH°ads, ΔS°ads, ΔG°ads were obtained from Tafel polarization at different temperatures (25–55 °C). This confirms that the adsorption of the inhibitor on the surface is carried out by an intermediate adsorption between physisorption and chemisorption in both acids. The Correlation between theoretical results of the Density Functional Theory (DFT) and experimental results is discussed