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

Abstract

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.