A Novel Corrosion Inhibition of Dodecylamine Ethyl Sulfonate on Titanium in Hydrochloric Acid Medium

To develop an effective corrosion inhibitor for titanium (Ti) alloys under acidizing conditions, dodecylamine was reacted with sodium 2-chloroethyl sulfonate to synthesize dodecylamine ethyl sulfonate (DAS), a sulfonic acid group containing compound. In this work, the corrosion inhibition performance of DAS was systematically evaluated in 20% hydrochloric acid solution at 90°C, simulating the highly aggressive environment of industrial acidizing operations. Weight-loss and electrochemical measurements confirmed that DAS exhibits excellent protective capability, achieving an inhibition efficiency of 92.8% at 5000 mg/L. Compared with conventional inhibitors such as mannich bases, quaternary ammonium salts, and imidazoline derivatives, DAS maintains both high efficiency and thermal stability for titanium alloys in hot HCl. This highlights the innovation of DAS as one of the few inhibitors capable of effectively protecting titanium alloys in concentrated hydrochloric acid at elevated temperatures. The findings not only broaden the application scope of surfactant-based inhibitors but also provide practical insights for corrosion control in demanding acidizing environments.