Abstract

Poly(indole-5-carboxylic acid) (PICA) has been synthesized by electrochemical polymerization technique from different concentration of poly(indole-5-carboxylic acid) using lithium per chloride as oxidation agent at different scan rate. The as-synthesized PICA was characterized using Fourier transform infrared spectroscopy (FT-IR) and Proton nuclear magnetic resonance spectroscopy (¹H-NMR). Thermal analysis of the PICA was performed by Thermo gravimetric analysis (TGA). The corrosion protection performance of low nickel stainless steel (LN SS) specimens coated with 0.1 M concentration of PICA was investigated in 0.5 M H₂SO₄ medium using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) methods. The morphological properties of the polymer were characterized by scanning electron microscopy (SEM). The as-synthesized PICA has been used in order to achieve adherent, as well as environmentally preferential good anti-corrosive coating. Electrochemical corrosion tests and surface analysis results evidently showed that PICA coating served as a stable mass matrix on LN SS against corrosion. It was also revealed that the coating of PICA at 0.1V scan rate with 0.1M indole-5-carboxylic acid exhibited the best corrosion resistance among all concentrations.

Keywords

LNSS, Indole-5-carboxylic acid, Corrosion protection, Electrochemical study