Theoretical and experimental studies of the corrosion behavior of some thiazole derivatives toward mild steel in sulfuric acid media

The corrosion behavior of iron in diluted aqueous sulfuric acid medium has been studied in the presence and absence of 6-ethoxybenzo[d]thiazol-2-amine (EBT), 5-bromothiazol-2-amine (BTA) and 4,5-dimethylthiazol-2-amine (DTA). Potentiodynamic measurements showed the shift of corrosion potential towards a more negative potential indicating that these compounds mostly act as cathodic inhibitors due to their adsorption on the iron surface. The adsorbed film of these molecules hinders the transport of metal ions from the metal to the solution and also retards hydrogen evolution reaction by acting as a physical barrier. The molecules were also studied by density functional theory (DFT), using the B3LYP functional in order to determine the relationship between molecular structure and the corrosion inhibition efficiencies.