Experimental Study of a Schiff Base as Corrosion Inhibitor for Mild Steel in 1M HCl

In this paper, salicylaldehyde ethylenediamine Schiff base (SESB) was prepared by reaction of salicylaldehyde and ethylenediamine at 60℃ for 4 h. The structure of SESB was characterized by hydrogen magnetic resonance spectroscopy. The corrosion inhibition effect of SESB on mild steel in 1mol L-1HCl was studied by weight loss method and electrochemical method. The results showed that the corrosion inhibition effect of SESB on mild steel at 1mol L-1 HCl was negatively correlated with the test temperature at 25℃ to 45℃, and positively correlated with the concentration of SESB at 0mmol L-1 to 5mmol L-1. The results showed that the maximum corrosion inhibition efficiency of SESB at 25℃, 30℃, 35℃, 40℃ and 45℃ were 70.73%, 58.42%, 54.68%, 37.73% and 25.12%, respectively. The results of electrochemical impedance test and electrochemical polarization test show that SESB can not only inhibit the anode metal dissolution of mild steel in 1mol L-1 HCl, but also inhibit the cathode hydrogen precipitation, which is a mixed corrosion inhibitor.