Correlation between experimental and theoretical approaches in the performance of new epoxy resin as an effective corrosion inhibitor for mild steel in acid pickling bath

•Electrochemical test data indicate that PGH is a good inhibitor.•PGH adsorbs on the steel/solution in accordance with the Langmuir model.•-Surface characteristics analysis provided strong evidence for the existence of inhibition film on steel surface.•Theoretical modeling provides deep insights into the inhibition performance of PGH. In this recent work, novelty epoxy resin namely 1,3,4,5,6-pentaglycidyloxy hexan-2-one (PGH) was synthesized characterized and studied as a potential anticorrosive protection for mild steel (MS) in 1 M HCl solution. The corrosion inhibition for MS was examined by “potentiodynamic” polarization (PDP), electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation measurements (EFM), scanning electron microscope coupled with energy dispersive X-ray spectroscopy (MES/EDS) and theoretical approaches (DFT and MD simulation). PGH elaborated was investigated by the Fourier transform infrared (FTIR) spectroscopy. Additionally, the inhibitory efficiencies found at higher concentration (10−3 M of the PGH) are 85.5% (EIS) and 88.6% (PDP), respectively. PDP results indicated that the PGH acted as a mixed-type inhibitor in 1 M HCl medium. SEM/EDS characterization represents a terrific decrease in corrosion of the MS surface within 10−3 M of PGH compared with the 1.0 M HCl pure. DFT calculation provided molecular level insights on the nature and the active centres of the corrosion inhibition efficiency of the PGH elaborated. MD simulation showed that the PGH has the maximum inhibition efficiencies at oxygen atoms.