Synthesis, characterization, theoretical, and experimental evaluation of novel imidazolone - based compounds as eco-friendly corrosion inhibitors for mild steel

This study investigates the corrosion inhibition properties of two newly synthesized namely (E)-2-(2-benzylidenehydrazineyl)-5,5-diphenyl-3,5-dihydro-4H-imidazol-4-one denoted Ph-DDI and (E)-2-(2-(4-methylbenzylidene)hydrazineyl)-5,5-diphenyl-3,5-dihydro-4H-imidazol-4-one denoted CH3Ph-DDI, on mild steel (MS) in a 1 M HCl solution. These compounds demonstrated high inhibition efficiencies of 98.3 % and 98.7 %, respectively. Structural characterization was performed using FT-IR, 1H NMR, 13C NMR, and HRMS-ESI. Theoretical evaluations indicated high reactivity and potent inhibition capacity. Electrochemical tests confirmed a concentration-dependent inhibition effectiveness up to 328 K. Adsorption studies suggested that the compounds displace water molecules to form an adsorbed protective layer. Microscopy analysis provided insights into the corrosion inhibition mechanisms, confirming the formation of protective layers and iron/inhibitor complexes. Further molecular structure analysis using Monte Carlo (MC) simulations and density functional theory (DFT) calculations elucidated the structural features contributing to the compounds' effective corrosion inhibition properties.