A New Acidizing Corrosion Inhibitor of Schiff Base and Its Corrosion Inhibition Performance

A new acidizing corrosion inhibitor ACR-1 of Schiff base was prepared from the materials of aniline and aromatic aldehydes by Schiff reaction. The effects of concentration of hydrochloric acid, corrosion temperature and concentration on the inhibitor to the inhibition efficiency of ACR-1 were studied by static weight loss method. The adsorption model of ACR-1 on the steel surface was dicussed. The electrochemical corrosion mechanism of the inhibitor was explored by electrochemical method. The experiment results showed that the corrosion rate of N80 was 1.6733 g·m-2·h-1 in the 15% hydrochloric acid solution with addition of 1.0% ACR-1 when the corrosion temperature was 90 ℃, the corrosion time was 4 h, meeting the first-class index of Oil Industry Standard SY/T 5405-1996 (3~4 g·m-2·h-1). The study of isothermal adsorption shows that the ACR-1 molecular can spontaneously be adsorbed on the surface of N80 steel and this adsorption process obeys Langmuir monomolecular adsorption model. The results of electrochemical method indicate that the ACR-1 is a mixed inhibitor mainly to inhibit the anodic reaction, which belongs to the “geometric covering effect”, and can form a clear protective layer on N80 surface and inhibit effectively the corrosion in acid solutions.