Corrosion Inhibition of N, N-Dimethyl-(4-Disproportionated Rosin Aminomethyl)-Phenylamine on Carbon Steel in HCl Solution

A reduced Schiff base corrosion inhibitor of N, N-dimethyl-(4-disproportionated rosin aminomethyl)-phenylamine (DDRAP) was synthesized from disproportionated rosin amine, and its inhibition efficiency for the corrosion of A3 steel in HCl solution was investigated by weight-loss measurement and polarization curves. The results of weight loss showed that the corrosion rate and inhibition efficiency for carbon steel were 0.2806 mg·cm-2·h-1 and 97.74 % respectively when the DDRAP concentration was 100 mg·L-1 in HCl solution at 60 ℃. The adsorption of DDRAP on A3 steel in HCl solution obeyed Langmuir isotherm and the obtained standard free energy depended on both physicosorption and chemisorption The influences of temperature and HCl concentration were also studied. Polarization curves reveal that DDRAP is a cathodic corrosion inhibitor.