Green synthesis of novel carbohydrate polymer chitosan oligosaccharide grafted on D-glucose derivative as bio-based corrosion inhibitor

A novel chitosan oligosaccharide macromolecule carrying a glucose moiety (COS-g-Glu) has been synthesized and used as a non-toxic, durable, and biodegradable inhibitor of mild steel corrosion in acidic medium (1.0 M HCl). This macromolecule was synthesized by grafting a glucose moiety on Chitosan, and characterized by FT-IR, H-1 and C-13 NMR. The add corrosion inhibiting effect of this biodegradable macromolecule is obtained by experimental electrochemical characterization (EIS and PDP), surface [Scanning Electron Spectroscopy (SEM), Energy Dispersive Spectroscopy (EDS), infrared (FT-IR), and Atomic Force Microscopy (AFM)]. Corrosive acidic solutions were identified by UV-visible spectroscopy (UV-vis) and by ICP-OES spectrometry. Electrochemical tests show that the inhibition efficiency increases with increasing concentration of the inhibitor and reaches an optimum value of 97% at 10(-3) M. The thermodynamic parameters, and steel surface characterization methods confirmed the adsorption of COS-g-Glu. The results obtained from the DFT, and MD calculations correlate with the results obtained experimentally. Published by Elsevier B.V.

Automated summary

A novel chitosan oligosaccharide macromolecule carrying a glucose moiety (COS-g-Glu) has been synthesized and proven effective as a non-toxic, durable, and biodegradable inhibitor of mild steel corrosion in acidic medium. Experimental results demonstrate that the corrosion inhibition efficiency of this macromolecule increases with the concentration of the inhibitor, reaching an optimum value of 97% at 10(-3) M.