Adsorption and anticorrosive behavior of aromatic epoxy monomers on carbon steel corrosion in acidic solution: computational studies and sustained experimental studies

Herein, the synthesis, characterization and corrosion inhibition effectiveness of two aromatic epoxy monomers (AEMs) namely, 2-(oxiran-2-yl-methoxy)-<i>N</i>,<i>N</i>-bis(oxiran-2-yl-methyl)aniline (AEM1) and <i>N</i>,<i>N</i>-bis(oxiran-2-ylmethyl)-2-((oxiran-2-ylmethyl) thio)aniline (AEM2), in carbon steel corrosive dissolution in 1 M HCl solution is investigated using computational and experimental techniques. AEM1 and AEM2 were characterized using FT-IR, ¹H NMR and ¹³C NMR spectroscopy techniques. Electrochemical results demonstrated that AEMs act as reasonably good corrosion inhibitors for carbon steel in 1 M HCl medium and their effectiveness followed the sequence: AEM2 (95.4%) > AEM1 (94.3%). A PDP study showed that AEMs act as mixed-type inhibitors with slight anodic predominance. Adsorption of the AEMs obeyed the Langmuir isotherm model. Interactions between AEMs and the metallic surface was further studied using DFT and MD simulations that give several computational parameters such as <i>I</i>, <i>A</i>, <i>E</i> _HOMO, <i>E</i> _LUMO, Δ<i>E</i>, <i>δ</i>, <i>χ</i>, <i>ρ</i>, <i>σ</i>, <i>η</i>, Δ<i>N</i> and <i>E</i> _ads. The experimental and computational results were in good agreement and well complimented each other.