Polyaniline Top Coat Modified on Nickel-Plated Mild Steel: AC Impedance Analyzer

• Published in: Polymer-plastics technology and engineering Vol. 45; no. 2; pp. 285 - 291
• Main Author: Ozyllmaz, A T
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01-01-2006; Taylor & Francis
• Subjects: AC impedance spectroscopy; Applied sciences; Corrosion; Exact sciences and technology; Forms of application and semi-finished materials; Metallic coatings; Metals. Metallurgy; Nickel plating; Nonmetallic coatings; Polyaniline; Polymer industry, paints, wood; Production techniques; Sheets and films; Surface treatment; Technology of polymers; Corrosion protective layer; Mild steel; Coating material; Salt corrosion; Metallizing; Experimental study; Property processing relationship; Polyaniline; Mechanism; Conducting polymers; Corrosion resistance; Corrosion; Nickel plating; Preparation; Oxidative polymerization; Porosity; Aniline polymer; AC impedance spectroscopy
• ISSN: 0360-2559; 1525-6111
• DOI: 10.1080/03602550500373881

Polyaniline (PANI) was synthesized from 0.1 M aniline containing neutral medium such as sodium oxalate. The synthesis was achieved on 1-µm Ni-plated mild steel (MS/Ni) by using cyclic voltammetry technique. The corrosion performances of PANI coating with and without MS/Ni electrodes were evaluated by using AC impedance spectroscopy (EIS) and anodic polarization curves in 3.5% NaCl solution. It was found that Ni plating showed an important barrier property on MS. This case decreased drastically in longer periods, and the porosity values increased in chloride ions medium, which has small ion diameter. In the presence of PANI top coat, the porosity values remained almost constant against the attack of corrosive products for extended periods. It indicated that PANI coating could provide a significant protection property to MS/Ni, by catalyzing the formation of a stable nickel oxide layers with time. The catalytic behavior of polymer film also contributed to improvement of barrier property of PANI coating due to transformation to the reduced structure.