Inhibition Behavior of Chito-Oligosaccharide Schiff Base Derivatives for Mild Steel in 3.5% NaCl Solution

摘要

Two new corrosion inhibitors of chito-oligosaccharide schiff base (CSB) and carboxymethyl chito- oligosaccharide schiff base (CM-CSB) were investigated by means of weight loss, potentiodynamicpolarization and electrochemical impedance spectroscopy (EIS) measurements in 3.5% NaCl solutionat different concentrations. The surface corrosion morphology of specimens was examined by scanningelectron microscopy (SEM) and the inhibition mechanism was analyzed by adsorption isotherm fittingand quantum chemical calculation. The results showed that for CSB the inhibition efficiency increasedat first, then decreased and reached the maximum at 200mg/L and acted as a mixed type inhibitor; theCM-CSB had excellent inhibition performance and behaved as a cathode-based mixed corrosioninhibitor. The adsorption of CM-CSB obeys the Langmuir isotherm.