Electrochemical investigation and surface interaction of thiophene based Chitosan Schiff base on mild steel surface in 1 M HCl

Abstract

Environment friendly Chitosan Thiophene carboxaldehyde Schiff base, a biopolymer derivative was synthesized to examine the inhibitive action of mild steel corrosion in 1 M Hydrochloric acid. Chitosan Thiophene carboxaldehyde Schiff base was prepared by the modification of Chitosan with thiophene carboxaldehyde through condensation reaction. The effect of Chitosan Schiff base as corrosion inhibitor was investigated using electrochemical impedance spectroscopy at higher temperature differentials of 313–343 K. Chitosan Schiff base showed enhanced corrosion resistance in all the studied temperature range by the forming protective film on the metal surface. The preliminary information about the complex formation in the solution phase, protective layer formation on the metal surface was investigated by Atomic absorption spectroscopy and Ultraviolet spectroscopic studies. The surface interaction between inhibitor molecules and mild steel surface was examined by Fourier Transform Infrared Spectroscopy, scanning electron microscopy and Contact angle measurements. The adsorption of inhibitor layer on the metal was monitored by cyclic voltammetry studies. Quantum chemical results support the possibility of surface interaction between inhibitor and empty orbitals of metal surface.