Effect of imidazoline derivatives on the corrosion inhibition of Q235 steel in HCl medium: experimental and theoretical investigation

Abstract In this work, two new imidazoline derivatives (SMF and SMIF) have been synthesized successfully, and their structure have been confirmed by IR, Raman, and NMR techniques. The corrosion inhibition ability and mechanism in HCl solution were proved by experimental and theoretical methods. The inhibition efficiency of SMIF was 94.69% in weight loss experiment, 95.99% (Tafel), and 95.30% (EIS) in electrochemistry. The corrosion inhibition mechanism is that SMF and SMIF form a stable protective film on the surface of Q235 and hinders charge transfer. EDS, FT-IR, and XPS all proved that SMF and SMIF inhibitors could stably adsorb on Q235 surface and form a protective film. The DFT and MD also proved the corrosion inhibiton mechanism. Experiments and theoretical calculations showed that SMF and SMIF exhibited excellent corrosion inhibition performance in 1 M HCl solution.