Corrosion Inhibition Mechanism of Benzimidazole and Its Derivatives on Mild Steel: Quantitative Structure and Property Relationship Study

A theoretical method named as quantitative structure and property relationship (QSPR) was used to investigate corrosion inhibition efficiency of benzimidazole and its derivatives on mild steel in 1 M hydrochloric acid. Some electronic, spatial and thermodynamic properties were selected as descriptors to build relationships between inhibition efficiency and micro-structure information. These descriptors include frontier molecular orbits (LUMO and HOMO), molecular surface area and molecular volume, molecular flexibility, etc. The relationships between descriptors and inhibition efficiency were described by several equations, respectively. Furthermore, an overall equation was built up to describe accurately the relationship between inhibition efficiency and most of the descriptors. These equations were proven to be successful in explaining the corrosion inhibition mechanism of benzimidazole and its derivatives.