Preparation and Characterization of Chitosan Grafted Tannic Acid for Anticorrosion Coating on Bronzeware

Abstract

The protective bronze film was prepared by mixing the reaction product of oligosaccharide (COS) and modified tannic acid (TA) with polyvinyl alcohol and polyethylene glycol. Chloroacetic acid to carboxylate TA was used to generate sodium tannate. N,N’-Dicyclohexylcarbodiumide (DCC)/1-Hydroxybenzotriazole (HOBt) was used as a condensing agent to form an amide bond between carboxylic acid and amine to form COS-TA. The synthesized product was characterized using FT-IR, NMR, and thermal analysis. The surface morphology of the coating made of the synthesized product was observed using an optical microscope and scanning electron microscope. Electrochemical methods were used to determine the stability and corrosion inhibition performance of the coating. FT-IR, NMR, and thermal analysis demonstrated that tannic acid and Chitosan oligosaccharides were successfully condensed. Electrochemical impedance spectroscopy showed that the impedance increased, the corrosion current was significantly reduced, and the coating had a significant anti-corrosion effect.