ELECTROPOLYMERIZATION OF PYRROLE ON COPPER AND HIS EVALUATION AS INHIBITOR IN THE PROCESSES OF CORROSION

Abstract

In this work, the electrochemical synthesis of the polypyrrole (Ppy) on passivated copper in different media for the study of the anticorrosive properties. These media: 0,3 mol L^-1 oxalic acid, phosphate buffer at a concentration of 0,10 mol L^-1 dihydrogen phosphate and 0,10 mol L^-1 hydrogen phosphate and 0,25 mol L^-1 sodium acetate covering a pH range of 1, 4 and 8 respectively. The electropolymerization process of pyrrole occurs in the potentials corresponding to the formation of Ppy, resulting in the adherence of a black material on them (Polypyrrole), characterized by Raman spectroscopy, a technique that informs us of the characteristic peaks of this material in our polymer, the main ones being obtained at 1540 cm^-1 corresponding to the vibration of the carbon-carbon double bond in the polymer chain and the one corresponding to the Ppy+ at 1310 cm^-1. Finally the studies of the anticorrosive activity by Tafel slopes results in an optimum value of 0,004 mm/year of corrosion rate for polypyrrole film electrodeposited by 40 cycles in oxalic acid against the corrosion rate of metallic copper of 0,907 mm/year.