Electropolymerization of pyrrole and N-methylpyrrole on mild steel surface

A. Ashrafi, M. A. Golozar, S. Mallakpour

Electropolymerization of pyrrole and N-methylpyrrole on mild steel surface

Iranian Polymer Journal Vol.12, No.6, pp.485-490, 2003.

A B S T R A C T

Electrochemical polymerization of various ratios of pyrrole and N-methylpyrrole
monomers were performed in aqueous toluene-4-sulphinic acid sodium salt
(T4SNa) electrolyte, using galvanostatic method. The pH of electrolyte was adjusted
by p-toluene sulphonic acid (PTSA). In order to prevent corrosion of mild steel substrates
during coating deposition, all samples were pretreated in 0.5 M oxalic acid solution,
employing galvanostatic method. This would passivate the steel substrate and facilitate
the coating process as well. Corrosion resistance of coated substrates was investigated
in 1 M NaCl solution using Tafel polarization technique. In addition, by using scanning
electron microscopy (SEM), morphological characterization of coatings produced,
was investigated. The ratio of 1 to 1 (pyrrole/N-methylpyrrole) could play an important
role on corrosion properties of the resulting coated mild steel.