Corrosion Inhibition of 3, 4-Bis(4-Hydroxy-3-Methoxybenzylideneamino)Benzoic Acid for 45# Steel

3, 4-Bis(4-hydroxy-3-methoxybenzylideneamino) benzoic acid (V-dba) was synthesized. Melting point test and UV-Vis spectrum, as well as FT-IR spectrum measurements were carried out to analyze the structure of the synthetic compound. The V-dba self-assembled films on steel electrode were investigated using electrochemical impedance spectroscopy (EIS) and polarization curve testing methods. Results showed that the compound was the target compound. Changing the concentrations and assembly times had an impact on the inhibition efficiency for steel corrosion. In the concentration of 0.360 mmol·L-1 V-dba-ethanol solution, the measurements were carried out in changing the self-assembly times. When the time was up to 12 h, the corrosion inhibition efficiency reached the maximum value of 92.0%. Under the condition of 12 h self-assembly time, tests of changing the concentration of the V-dba-ethanol solution were performed. The test results show that the corrosion inhibition efficiency increased with the increase of V-dba concentration.