Inhibition of Mild Steel Corrosion by New Epoxy Resin in 1 M HCl: Synthesis, Characterization, Experimental Study and Theoretical Approach

Herein, in this potential work, we investigate the novelty epoxy resin namely diglycidyl ether bismercapto bisphenyl sulfone difunctional epoxide resin (DER) as an excellent corrosion inhibitor for mild steel area in 1 M HCl environment. This epoxy resin was obtained by condensation reaction between 4,4-dichlorodiphenyl sulfone and mercaptoethanol. FTIR, 1H NMR and 13C NMR were used to confirm the structure of DER synthetized. Anticorrosive properties were evaluated including X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and electrochemical measurements. Theoretical computations (DFT) and molecular dynamics simulations were employed to examine the reactivity and interaction between the DER and the Fe surface. In additional, at a DER concentration of 10^–3 M, potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) curves revealed that DER functioned as a barrier against MS surface corrosion, with inhibitory effectiveness of 97.2 and 96.9%, respectively. In addition, it was found that, in agreement with the Langmuir adsorption isotherm, DER adsorption was a chemisorption process. The development of a protective barrier through the electrode region of interest caused significant changes in the surface morphology of the MS electrode, as demonstrated by SEM and EDS analysis.