Corrosion Protection Efficacy of the Electrodeposit of Poly (N-Methyl Pyrrole-Tween20/3-Methylthiophene) Coatings on Carbon Steel in Acid Medium

Abstract

In this study, poly(N-methylpyrrole-Tween20/3-methylthiophene) coatings were electrodeposited on carbon steel type OLC 45 by electrochemical techniques in oxalic acid solution. Surfactant Tween 20 as a dopant ion employed during electropolymerization can have an important influence on the corrosion protection of this coating by obstructing the penetration of aggressive sulfate ions. The new composite coatings have been analyzed electrochemically, spectroscopically and morphologically by cyclic voltammetry, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) methods. Corrosion protection consideration of PNMPY-TW20/P3MT-coated OLC 45 has been analyzed by potentiostatic and potentiodynamic polarization, open circuit potential and electrochemical impedance spectroscopy (EIS) measurements in 0.5 M H2SO4 medium. The corrosion rate of PNMPY-TW20/P3MT-coated OLC 45 has been indicated to be ~10 times reduced compared to uncoated OL 45, and the corrosion protection efficiency of the coating is above 90%. The greatest efficacy is achieved by PNMPY-TW20/P3MT composite by electrodeposition at 5 mA/cm2 and 3 mA/cm2 current densities applied and at 1200 mV potential applied in 5:1 and 3:5 molar ratios. The PNMPY-TW20/P3MT coating realized by the galvanostatic method exhibited a non-damaging surveying after 96 h of immersion in the aggressive medium, further verifying its excellent protection capacity. The consequences of the corrosion experiments clearly divulged that PNMPY-TW20/P3MT coatings ensure a very good anticorrosion protection of OLC 45 in aggressive medium.

Recent Progress of Polymeric Corrosion Inhibitor: Structure and Application

“…Thiophene can also be copolymerized with other monomers to improve the anti-corrosion property. For example, Branzoi et al [60] investigated the anti-corrosive properties of poly(N-methylpyrrole-Tween20/3-methylthiophene) coatings on carbon steel type OLC 45 in 0.5 M H 2 SO 4 medium. The surfactant Tween 20 was a dopant used in the electropolymerization process, which could improve the anti-corrosive properties by hindering the corrosive sulfate ion penetration.…”

Anticorrosion Protection of New Composite Coating for Cobalt-Based Alloy in Hydrochloric Acid Solution Obtained by Electrodeposition Methods

“…Hence, it is assumed that the integration of hydrophobic functional groups increases the protective capacity of polymers. Dopants incorporated into polymers provide control over the electrodeposition practice and the attributes of the achieved polymeric composites [47][48][49][50][51][52][53][54]. The application of dopant ions in electrochemical polymerization can have an important effect on the number-selective ion exchange of polymers.…”

“…In previous works, we studied the protection performance of different composite polymer films obtained from different conducting polymers (polyaniline, polypyrrole, and polythiophene and their derivatives: PPY-AOT/PNEA, PNNDMA/PPY-SDS, PNMPY-TW20/P3MT, PNMPY-1SSD/P2MT, and PNMPY-TRX-100/PNNDEA) under the influence of different dopants (surfactants with large hydrocarbonate chains such as AOT, SDS TRX100, TW20, 1-SSD, and SDBS) made using different electrochemical methods (potentiostatic, galvanostatic, and cyclic voltammetry procedures) on different substrates (OL 37, OLC45, OL50, copper, and brass alloy) in different corrosive environments where the results were remarkable: every time, the composite polymer films had an efficiency of over 90%, and the corrosion rate was 9-10 times lower than that of an uncoated substrate [10,14,20,38,40,50]. By exploring the efficaciousness of composite coatings, this research aims to ensure a possible method to diminish corrosion and enhance the lifetimes of metals and their alloy constituents.…”