Microwave-Assisted Preparation of 2-(Benzylthio)imidazole and 2-(Benzylthio)benzimidazole and its Comparative Corrosion Inhibiting Performance with 2-Mercaptoimidazole and 2-Mercaptobenzimidazole

In this paper, the anticorrosive performance of four inhibitive organic heterocyclic compounds [2-Mercaptoimidazole (2MI), 2Mercaptobenzimidazole (2MBI), 2-(Benzylthio)imidazole (2BZMI) and 2-(Benzylthio)benzimidazole (2BZMBI)] were investigated using pipeline steel in hydrochloric acid media (1M HCl) and compared using electrochemical impedance spectroscopy, EIS. The last two organic compounds were obtained through non-conventional synthesis using microwaves. As the inhibitors concentration increased from 5-200 ppm, Z’re also increased continuously, thereby suggesting inhibitor adsorption onto the metal surface. Also, all the organic inhibitors studied showed acceptable corrosion inhibiting efficiency, IE, of about 9496% after adding 30 ppm to the acid system. Furthermore, at this concentration the better protection efficiency was attained for the inhibitor 2BZMBI. The four inhibitive organic compounds were classified as mixed inhibitors, in accordance with the corrosion mixed potential theory.