Electrochemical and thermodynamical investigation of schiff's bases of glycine and aldehydes on corrosion inhibition behavior of mild steel in 1M hydrochloric acid medium

Abstract

Three Schiff's bases (SBs) namely 2-(2-hydroxybenzylidene amino) acetic acid (HBAA), 2-(4-(dimethylamino) benzylidene amino) acetic acid (DMBA), and 2-(2-hydroxy-4-methyxybenzylidene amino) acetic acid (HMBA) were synthesized and their effects on the electrochemical behavior of mild steel in 1 M HCl was investigated using gravimetric measurements, Tafel extrapolation technique, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) methods. Tafel polarization measurements revealed that these Schiff's bases act as mixed-type inhibitors. Among the studied SBs, HMBA exhibited the best inhibition efficiency of 95% at 400 ppm concentration. Some thermodynamic parameters were also determined to investigate the mechanism of adsorption. The results obtained from weight loss and electrochemical methods are in good agreement.