A Novel Trimeric Quaternary Ammonium Salt and Its Inhibitive Effect on Iron Corrosion in Hydrochloric Acid Medium

A novel trimeric quaternary ammonium inhibitor, citric triesters of tri (dodecyldimethyl-2-hydroxypropane) ammonium chloride (CTTAC), was synthesized. Its inhibitive effect was investigated by static mass-loss and steady-state polarization curve methods, taking iron immersion in 1 M hydrochloric acid for example. The related values of mass-loss and steady-state polarization curve methods enhanced with the added CTTAC concentration increasing. When the added concentration was close to the critical micelle concentration, those values reached the optimum. The inhibitor appeared to be adsorbed on the metal/liquid interface through the general adsorption mode following Langmuir adsorption isotherm model. According to the relationship between inhibition efficiency and the concentration of the CTTAC, a modified Langmuir adsorption isotherm model was established and the adsorption coefficient K, Delta G(0), Delta H-0, and Delta S-0 for the CTTAC on the iron surface adsorption at different temperatures were obtained. All the experimental data indicated that the CTTAC had an excellent inhibition efficiency.