β-Cyclodextrin Modified Natural Chitosan as a Green Inhibitor for Carbon Steel in Acid Solutions

Inhibition of carbon steel corrosion in 0.5 M hydrochloric acid solutions by β-cyclodextrin modified natural chitosan was investigated by weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The results indicated that the inhibition efficiency increased with the inhibitor concentration at 298 K. The experimental results revealed that β-CD–chitosan (β-cyclodextrin modified chitosan) was a mixed inhibitor with a maximum achievable inhibition efficiency of 96.02%. Adsorption of β-CD–chitosan was found to follow the Langmuir adsorption isotherm which involved both physisorption and chemisorption. The results of SEM and EDS studies further confirmed the inhibition action of polymer.