The electrochemical synthesis of polypyrrole at a copper electrode: corrosion protection properties

Pyrrole was successfully electropolymerized at a copper electrode in a near neutral sodium oxalate solution to generate a homogeneous and adherent polypyrrole film. The growth of these films was facilitated by the initial oxidation of the copper electrode in the oxalate solution to generate a copper oxalate pseudo-passive layer. This layer was sufficiently protective to inhibit further dissolution of the copper electrode and sufficiently conductive to enable the electropolymerization of pyrrole at the interface, and the generation of an adherent polypyrrole film. These films remained stable and conducting for periods exceeding eight days and exhibited significant corrosion protection properties in acidified and neutral 0.1 mol dm(-3) NaCl solutions even on polarization to high anodic potentials. (C) 2002 Elsevier Science Ltd. All rights reserved.