Poly(o-anisidine) and poly(o-anisidine-co-aniline) polymers synthesized on the ZnFeNi alloy coated steel surface

Abstract

ZnFeNi alloy was synthesized on the carbon steel surface in a sulfate bath using the galvanostatic method at a constant current of 1.5 mA for 300 seconds. Poly(o-anisidine) homopolymer and poly(o-anisidine-co-aniline) copolymer were synthesized on the ZnFeNi coated electrode surface. Poly(o-anisidine) homopolymer was synthesized in 0.05 M o-anisidine+0.2 M sodium oxalate medium, and poly(o-anisidine-co-aniline) copolymer was synthesized in 0.05 M o-anisidine+0.05 M aniline+0.2 M sodium oxalate medium. Electrochemical synthesis was carried out by cyclic voltammetry technique. The synthesized materials were characterized by electrochemical impedance spectroscopy, linear sweep voltammetry, open circuit potential-time and anodic polarization curves. Open circuit potential-time curves showed that polymer coatings had higher open circuit potential. By linear sweep voltammetry measurements, it was determined that ZnFeNi alloys were present at the base of the polymer layers after polymer synthesis. It was understood from the anodic polarization curves that the polymer coated electrodes had lower current values ​​than the uncoated ZnFeNi coated electrode, and the poly(o-anisidine) coated electrode had lower current values ​​than the poly(o-anisidine-co-aniline) coated electrode. From electrochemical impedance spectroscopy measurements, it was determined that the polarization resistance of polymer-coated electrodes was higher than the polymer-free electrode during long periods of waiting in 3.5% corrosive solution. Among the polymer-coated electrodes, it was understood that the homopolymer poly(o-anisidine) showed better corrosion performance than the poly(o-anisidine-co-aniline) copolymer.