Development of a new high-efficient corrosion inhibitor based on gemini imidazoline

Conventional imidazoline corrosion inhibitors are widely used for corrosion prevention, but their corrosion inhibition effect is not good. And furthermore, they are used at a high concentration and the formed inhibition film is poor in persistency. In this paper, therefore, a new type of high-efficient and environment-friendly corrosion inhibitor, i.e., gemini imidazoline corrosion inhibitor was developed. It is composed of two hydrocarbon chains and two headgroups which are linked by a rigid spacer. Its CO₂ corrosion inhibition performance was analyzed by using electrochemical linear polarization test, and the persistency of its inhibition film was evaluated by means of corrosion weight loss test. Test results show that gemini imidazoline corrosion inhibitor is more effective at a low concentration. The mixture of gemini imidazoline with fatty acid is better in film persistency and less in emulsifying tendency than conventional inhibitors. Compared with conventional imidazoline, gemini imidazoline is much higher in surface activity and several times lower in critical micelle concentration. Hence, the new type of gemini imidazoline corrosion inhibitor and its mixture are not only more effective in corrosion inhibition at a low concentration, but also more friendly to the environment.