Synthesis and Properties of CJ Mannich Base as a Corrosion Inhibitor

Mannich base is a kind of important corrosion inhibitors. CJ Mannich base inhibitor was synthesized with cinnamyl aldehyde, cyclohexanone and hydrazine hydrate as raw materials. The optimum synthesis conditions were obtained by orthogonal test. The corrosion inhibition mechanism of CJ Mannich base as acidizing corrosion inhibitor was analyzed by polarization curves and EIS. The results showed that the optimum synthesis conditions were as follows: molar ratio of cinnamyl aldehyde to hydrazine hydrate was 3∶1, molar ratio of cyclohexanone to hydrazine hydrate was 1∶1, the temperature was 45 ℃, pH value was 4, the synthetic time was 8 hours. The results of static weight-loss showed that the corrosion rate of N80 steel plate in 15% HCl solution was 0.299 1 g/(m2·h), when the dosage of inhibitor added was 1.0%, which was lower than the first grade standard of SY/T 5405-1996, and the inhibitor had good heat-resistance and aicd-tolerance. The adsorption behavior of CJ Mannich base corrosion inhibitor on the surface of steel conforms to Langmuir adsorption isotherm. Electrochemical test showed the inhibitor of CJ Mannich base belonged to a mainly anodic-controlling composite corrosion inhibitor.