Experimental, DFT and molecular dynamics simulation on the inhibition performance of the DGDCBA epoxy polymer against the corrosion of the E24 carbon steel in 1.0 M HCl solution

Abstract The inhibition performances of the epoxy polymer S, S′-diglycidyl O, O′- dicarbonodithioate of bisphenol A (DGDCBA) on the corrosion of the E24 carbon steel in 1.0 M HCl in the absence and in the presence of different concentrations (10 −3 to 10 −6  M of DGDCBA). Then, the results obtained by using gravimetric measurements and electrochemical methods show that the tested DGDCBA epoxy polymer is a very effective inhibitor to the inhibition of corrosion. Furthermore, the inhibition efficiency of the epoxy polymer increases with increasing concentration and reaches a maximum value of 91%, 98% and 96% for the concentration of 10 −3  M of the DGDCBA for gravimetric and electrochemical measurements (stationary and transient methods), respectively. Moreover, this polymer has characteristics which facilitate their adsorption on the surface of the metal substrate, in particular the existence of aromatic rings and heteroatoms (O and S). In addition, we proceeded to compute quantum chemical descriptors using the density functional theory (DFT) method with 6–31 G (d,p) basis sets. Finally, the molecular dynamics simulation confirms the results obtained by the DFT and the experimental data.