Effect of Temperature on Adsorption Behavior and Corrosion Inhibition Performance of Imidazoline-Type Inhibitor

Abstract In the present study, the effect of temperature on the adsorption/desorption kinetics and thermodynamics of diethylenetriamine talloil fatty acid imidazoline (DETA/TOFA imidazoline) is studied on a gold coated crystal using a quartz crystal microbalance (QCM) in a CO2 saturated 1wt% NaCl aqueous solution. Concurrently, the corrosion inhibition performance of imidazoline on API 5L X65 steel was also investigated at different temperatures using linear polarization resistance (LPR). QCM results show that the adsorption of imidazoline-type inhibitor generally follows the Langmuir adsorption process and the desorption of inhibitor is favored with increasing temperature. While both adsorption and desorption rate constants increase with temperature, the effect on desorption was found to be more pronounced. Inhibition test results generally agree well with those obtained in the adsorption study and the loss of corrosion inhibition efficiency observed at higher temperature is attributed to a greater rate of desorption of the inhibitor.