SYNTHESIS AND PERFORMANCE EVALUATION OF A BIS-SCHIFF BASE AMINO ACID CORROSION INHIBITOR

This study synthesized a bis-Schiff base amino acid corrosion inhibitor (CBS) via the condensation reaction between cysteine and glutaraldehyde. The synthesis of CBS was confirmed by Fourier-transform infrared spectroscopy (FTIR). The corrosion inhibition behavior of CBS on Q235 steel in 1 M HCl solution was systematically investigated through weight loss measurements, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and thermodynamic analysis. Weight loss results demonstrated that CBS effectively suppressed the dissolution of Q235 steel in 1 M HCl. At 303 K and a concentration of 150 mg/L, CBS achieved a corrosion inhibition efficiency of up to 94.83%. Polarization curves revealed that both anodic and cathodic branches shifted toward lower current densities upon CBS addition, classifying it as a mixed-type inhibitor. Thermodynamic analysis indicated that the adsorption of CBS on Q235 steel followed the Langmuir isotherm model, predominantly governed by chemisorption.