MONOLAYER AND BILAYER CONDUCTING POLYMER COATINGS FOR CORROSION PROTECTION OF COPPER IN 0.5 M H_2SO_4 SOLUTIONS

摘要

In this study, monolayer poly (N, N' dimethylaniline) (PNDMA), polyaniline (PANI), and bilayer PNDMA/PANI, PANI/PNDMA coatings have been electropolymerization on copper by potentiodynamic and galvanostatic synthesis techniques from aqueous solutions 0.1 M N,N' dimethylaniline, 0.1M aniline, 0.05 M sodium dodecyl sulphate (SDS) and 0.3 M oxalic acid. In order to include dodecylsulphate ions as dopant in the N, N' dimethylaniline, SDS was also added to the polymerization solution of N, N' dimethylaniline. Characterization of monolayer and bilayer polymer coatings was carried out by cyclic voltammetry, Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) techniques. Corrosion behaviour of PNDMA-SDS/PANI coated copper was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques in 0.5M H_2SO_4 solutions. The results of the corrosion tests showed that PNDMA-SDS/PANI coatings ensure good corrosion protection of copper in aggressive media. Bilayer coatings revealed better corrosion inhibition efficiencies than monolayer coatings.