Synthesis and Performances Analysis of Imidazoline Quaternary Ammonium Salts Containing Thioureido Group

Three different kinds of imidazoline quaternary ammonium salts were synthesized with the use of valeric acid, decanoic acid, oleic acid, diethylenetriamine, benzyl chloride and thiourea as raw materials. The corrosion inhibition performances on carbon steel in HCl solution were measured via static weight loss method and polarization curve method. Partition coefficients in water and oil were measured, from which thermodynamic parameters of G0→w、ΔS0→w and ΔH0→w were obtained. Temperature effect on the mass transfer between water and oil were examined.Corrosion inhibitor protection is an effective solution to oil field corrosion problems in the acidification process [1]. Most organic inhibitor molecules contain lone pair electrons and rich π-electron such as O, N, S, P atoms or polar groups [2]. Imidazoline compounds contain N nuclei and unsaturated double bond of the larger electronegativity and it has a strong adsorption in the steel surface. Because it has good thermal stability, low toxicity and no irritating odor [3,4], it is considered to be excellent corrosion inhibitors in acidic solution.