Electrochemical investigations on the performance of newly synthesized azomethine polyester on rebar corrosion

Novel azomethine-based polyester is synthesized and the structure of the products is confirmed by 1H NMR, FT-IR, and XRD. The as synthesized polymer is employed as inhibitor against the corrosion of rebar in artificially simulated concrete pore solution with chloride contamination (blank) by means of Tafel polarization and electrochemical impedance measurements. First time in literature, azomethine polyester is employed as inhibitor for rebar corrosion. Polarization studies exhibited the maximum inhibition efficiency of 98% at 1000 ppm concentration. Electrochemical studies revealed the mixed-type nature of the inhibitors. The adsorption behavior of as synthesized polymeric inhibitor obeys Langmuir adsorption model. Mechanisms reveal the entire molecule is expected to adsorb on to the metal surface with near flat orientation and tend to arrange themselves parallel to each other covering the entire metal surface, hence, preventing the ingress of aggressive species to the metal surface. Further, SEM and atomic force microscope have proven the presence of adsorptive layer on the rebar under the simulated atmosphere.