The Study of 2, 4-Diamino-6-methly-1, 3, 5-triazine on the Corrosion Inhibition of Mild Steel in The Hydrochloric Acid Medium: Integrated Theoretical and Experimental Investigations

Abstract

The aim of this study is the investigation of adsorption and corrosion behaviors of 2,4-Diamino-6-methly-1,3,5-triazine (2-DMT) on mild steel (MS) in 0.5 M HCI solution using many experimental and theoretical studies such as potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), adsorption isotherm, potential of zero charge (PZC), scanning electron (SEM), atomic force microscopies (AFM) and quantum chemical calculations. The results showed that 2-DMT has an outstanding anti-corrosion performance of 94.6% at an optimum concentration of 10 mM and the MS surface, which was exposed to the inhibited solution at 298 K, does not contain pits, cracks or deformations. Values of icorr are found to be 0.51, 0.22, 0.098, 0.072 and 0.039 mA cm-2 for blank solution and each concentration of 2-DMT. Hydrogen volumes are 90 and 4.6 mL cm-2 for blank solution and the existence of 10.0 mM 2-DMT, respectively. The observed adsorption is much more consistent with Langmuir. The high performance is explained by the effective adsorbing of organic matter to the MS surface. HOMO, LUMO energies and the energy gap (∆E) are -7.1980, -1.9959 and 5.2021 eV, respectively. Accordingly, it is suggested that this organic compound can be used in the industrial acid cleaning procedure.