Research on hydroxyethyl ammonium O,O′-diphenyl dithiophosphate: Synthesis, characterization, surface activity and corrosion inhibition performance

Hydroxyethyl ammonium O,O′-diphenyl dithiophosphate (HADD) acting as a surfactant and corrosion inhibitor was successfully synthesized and characterized by FT-IR, ¹H NMR and single crystal X-ray diffraction. Meanwhile, the inhibition effect of HADD on Q235 steel (Q235s) corrosion in H₂SO₄ solution was studied by weight loss and potentiodynamic polarization measurements. HADD turned out to be an effective corrosion inhibitor and the inhibition efficiency increased with HADD concentration increasing, and significantly decreased with increasing both temperature and H₂SO₄ concentration. Potentiodynamic polarization measurements indicated that HADD was a mixed-type inhibitor.