Effects of electrochemical process parameters on the synthesis and properties of polypyrrole coatings on steel

Polypyrrole coatings have been successfully formed on low carbon steel by aqueous electrochemical process. The effects of electrochemical process parameters such as pH of the reaction medium, applied current density and initial monomer and electrolyte concentrations on the formation process of polypyrrole coatings were systematically investigated. The composition and morphology of the coatings were studied by FT-IR, elemental analysis and scanning electron microscopy (SEM). Our results show that passivation of the steel, electropolymerization of pyrrole, the morphology and properties of the coatings were all dependent on the electrochemical process parameters. By proper choice of the electrochemical process parameters, the passivation of the steel could be established within a short time and smooth, uniform, strongly adherent coatings could be formed on the steel substrate.