Evaluating four synthesized Schiff bases as corrosion inhibitors on the carbon steel in 1 M hydrochloric acid

Abstract

The corrosion inhibition efficiency of 2-((pyridin-2-ylimino)methyl)phenol (S1), 2-((hexadecylimino)methyl)phenol (S2), 2-((4-hydroxyphenylimino)methyl)phenol (S3), and 1-(4-(2-hydroxybenzylideneamino)phenyl)ethanone (S4) for carbon steel in 1M HCl has been studied. Weight loss, polarization and electrochemical impedance spectroscopy experiments showed that the Schiff base (S2) is the best used inhibitor. Results of electrochemical impedance and Tafel polarization measurements consistently showed that, both compounds are good inhibitors. Polarization curves indicated that the studied Schiff bases acted as mixed (cathodic/anodic) inhibitors. The differences in the corrosion inhibition efficiency between four studied Schiff bases are correlated with their chemical structures.