Inhibition performance of a new series of mono-/diamine-based corrosion inhibitors for HCl solutions

New mono- and diamine compounds were synthesized from dodecylamine and 1,12-dodacanediamine and evaluated as acid corrosion inhibitors for low-carbon steel. The inhibition behavior of these compounds was examined using gravimetric and electrochemical methods (linear polarization and Tafel plot). Weight-loss tests were conducted in IM HCl at 60°C for six hours. To simulate acid stimulation treatments, other weight-loss tests were conducted using typical acid stimulation concentrations of 4.1 and 7.7M HCl at 6O°C for 2 hours. The effects of corrosion inhibitor type, concentration, and acid concentration were investigated. Aromatic and multiple bonds substituents introduced to monoand diamine compounds were found to enhance inhibition performance compared to the starting materials (dodecylamine and 1,12-dodacanediamine). This is attributed to the π-electrons present in aromatic and to polymerization of substituents with multiple bonds. Both dodecylamine derivatives with a triple bond or an aromatic substituent exhibited excellent protection in 4.1M HCl. However, the derivative with a triple bond showed the best protection (98%) at 7.7M HCl. This result is very promising and suggests that this corrosion inhibitor has a good potential to be used in acid stimulation treatments conducted in oil and gas wells.