Insight on the corrosion inhibition of nanocomposite chitosan/boron nitride integrated epoxy coating system against mild steel

Abstract

Research in the field of organic and inorganic corrosion inhibitors has become prominent in recent years whereas its applicability is limited owing to the toxicity, non-biodegradability, low inhibition efficiency, etc. Polymer nanocomposites have high mechanical strength, stiffness, toughness, and thermal stability. They act as barriers against moisture and gases which enhance their applicability to various fields. The present study focuses on the synthesis of nanocomposite of chitosan/boron nitride (CS-BN) by sol-gel process and incorporated into epoxy matrix. The composite is then characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). XRD results show that nano hexagonal boron nitrides are finely scattered in the chitosan matrix. The thermal stability of the CS-BN composite was studied with TGA. The study depicts that boron nitride increases the thermal stability of chitosan. The corrosion protection features of biocompatible chitosan/boron nitride nanocomposite on mild steel (MS) substrate in 1 mol/L HCl solution were monitored by potentiodynamic polarization studies (Tafel), electrochemical impedance spectroscopy (EIS), and linear polarization studies (LPS). X-ray photoelectron spectroscopy (XPS) analysis was adopted to propose the mechanism of corrosion and also used to compare the corrosion inhibition behavior of BN in composite on MS surface.