New imidazole-based dimers as potential inhibitors for mild steel corrosion in acidic media: Electrochemical and DFT evaluation

We report the synthesis and corrosion inhibition performance of two imidazole-based materials, 1,1′-(4-methyl-1,3-phenylene)bis(3-(3-(1H-imidazol-1-yl)propyl)urea) (PIP) and 1,1′-(hexane-1,6-diyl)bis(3-(3-(1 H-imidazol-1-yl)propyl)urea) (HIP) dimers, in 1.0 M HCl. Electrochemical assessments indicated that the synthesized dimers facilitated the formation of a protective layer at the metal-electrolyte interface and, as a result, blocked the active corrosion sites. At a concentration of 100 ppm, PIP behaved as a potential mixed-type anticorrosive material with an overall efficiency of 99%. Density functional theory calculations showed that the aromaticity existing in the PIP backbone plays a major role in facilitating the corrosion-inhibition role.