Heptadecyl-tailed mono- and bis-imidazolines: A study of the newly synthesized compounds on the inhibition of mild steel corrosion in a carbon dioxide-saturated saline medium

• Published in: Corrosion science 2012-12, Vol.65, p.104-112
• Main Authors: Jawich, Mohammed W.S., Oweimreen, G.A., Ali, Shaikh A.
• Format: Article
• Language: English
• Subjects: A. Mild steel; Applied sciences; B. Polarization; C. Acid corrosion; C. Interfaces; C. Thermodynamic diagrams; Carbon dioxide; Carbon steels; Corrosion; Corrosion environments; Corrosion inhibitors; Corrosion tests; Exact sciences and technology; Imidazoline; Inhibition; Metals. Metallurgy; Saline
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2012.08.001

The study compares the inhibition of mild steel corrosion in a carbon dioxide-saturated saline medium. [Display omitted] ► New mono- and bis-imidazolines having heptadecyl pendants have been prepared. ► Inhibition of mild steel corrosion by the imidazolines in NaCl–CO2 is compared. ► Imidazolines cover most of the metal surface before reaching their CMCs. ► At a 100ppm concentration at 40°C, the bis-imizdazoline provided a 96% IE. ► Bis-imidazoline gave better protection than the mono-imidazolines. The study compares, for the first time, the corrosion inhibition properties of a diethylenetetramine-derived imidazoline (I), and tetraethylenepentamine-derived imidazoline (II) and bis-imidazoline (III), all having heptadecyl pendants as hydrophobes. The newly synthesized imidazolines show excellent inhibition efficiencies against the corrosion of mild steel in 0.5M sodium chloride solutions saturated with carbon dioxide. The inhibition efficiencies increased with the increasing temperature. At a concentration of 100ppm at 40°C, imidazolines I, II, and III imparted inhibition efficiencies of 84, 95 and 96%, respectively. The imidazolines cover most of the steel surface before their critical molar concentrations are reached.