Evaluation of Corrosion Protection Performance of New Polymer Composite Coatings on Carbon Steel in Acid Medium by Electrodeposition Methods

Abstract

In this research, electrodeposition procedure was utilized for the synthesis of a new composite polymer: N-methylpyrrole–Triton–X100/N, N,N-diethylaniline (NMPY-TRX100/NNDEA) used as a coating on carbon steel type OL 37 electrode for corrosion protection. The surfactant Triton–X100, a dopant ion utilized throughout the process of electropolymerization, had a significant impact on the corrosion protection of this composite by impeding the penetration of corrosive ions. PNMPY-TRX100/PNNDEA coatings were successfully realized on the OL37 substrate by a galvanostatic method of synthesis using the solutions 0.1 M NNDEA, 0.1 M MPY, 0.03 M TRX-100, and 0.3 M H2C2O4, at varied current densities (3 mA/cm2, 5 mA/cm2 and 8 mA/cm2) in different molar ratios (1:1, 1:5, 3:2 and 5:1). The deposition was performed for 20 and 30 min. The polymeric composite coatings were characterized electrochemically, spectroscopically, and morphologically by cyclic voltammetry, Fourier transform infrared spectroscopy, and scanning electron microscopy methods. Corrosion protection performance of PNMPY-TRX100/PNNDEA-coated OL 37 was examined through potentiostatic and potentiodynamic polarization, open circuit potential measurements, and electrochemical impedance spectroscopy procedures in 0.5 M H2SO4 media. The corrosion rate of PNPMPY-TRX100/PNNDEA-coated OL 37 was denoted to be around nine times less than that of an uncoated electrode. The corrosion protection yield of the coating was more than 90%. The best effectiveness was realized for PNMPY-TRX-100/PNNDEA by electrodeposition at 5 mA/cm2 current density applied in molar ratios of 5:1 and 3:2, and at 8 mA/cm2 current densities applied in molar ratio 5:1. The outcomes of the corrosion experiments revealed that PNMPY-TRX-100/PNNDEA coatings provide a good anticorrosion protection of OL 37 in corrosive solutions.