A NEW APLLICATION OF N,N’-BIS[(BENZIMIDAZOL-1-YL)ETHYL]-4-METHYLBENZENESULFONAMIDE AS CORROSION INHIBITOR FOR MILD STEEL

Abstract

Corrosion is one of the main problems in the industry that is associated to significant economic losses, such as loss or contamination of the product, reduction in efficiency, and increase of maintenance. This study had synthesised the compound from N-heterocyclic carbene (NHC) groups, namely N,N’-Bis[(benzimidazol-1-yl)ethyl]-4-methylbenzenesulfonamide (bis-benzimidazole). Its performance as a corrosion inhibitor of mild steel in acidic medium (1 M HCl and 1 M H2SO4) was measured at different temperature, time, inhibitor concentration, and salinity of water. The structure of bis-benzimidazole was confirmed using attenuated total reflection-Fourier transform infrared (ATR-FTIR), ultraviolet-visible (UV-Vis), and nuclear magnetic resonance (NMR) spectroscopies. The bis-benzimidazole (0.01 M) was successfully used as corrosion inhibitor in 8 h reaction time at room temperature with 100% and 92.51% inhibition efficiency in 1 M HCl and 1 M H2SO4, respectively. This showed that the bis-benzimidazole would adsorb chemically on mild steel surface, forming a protective layer that interfaces with the electrochemical reactions involved in the corrosion process.

Keywords

• acidic medium
• corrosion inhibitor
• mild steel
• n-heterocyclic carbene