Tetrahydropyrimido-Triazepine derivatives as anti-corrosion additives for acid corrosion: Chemical, electrochemical, surface and theoretical studies

The inhibition efficiency (IE) of 4-hydroxy-8-isocyano-9-phenyl-3-(p tolyl)-1,2-dihydropyrimido[2,1-c] [1,2,4] triazepine-5,7-dione (TRC-H) and 9-(4-chlorophenyl)-4-hydroxy-8-isocyano-3-(p-tolyl)-1,2-dihydropyrimido [2,1-c] [1,2,4]triazepine-5,7-dione (TRC-Cl) on the mild steel (MS) corrosion in 1 M HCl acid was studied by weight loss, electrochemical (EIS and PDP) techniques, DFT, molecular dynamic (MD) simulations, radial distribution function (RDF) and mean square displacement (MSD). TRC-H and TRC-Cl effect on the surface of MS has even been accentuated by scanning electron microscopy (SEM) and UV-visible. The adsorption on the steel is made according to the Langmuir model. Molecular dynamics simulation (MD) and Density Functional calculations were done to discussing their agreement with previously experimented results.