Improvement of Corrosion Resistance of Copper by Polypyrrole Film

BTA and silica showed synergistic enhancement of corrosion resistance and conductivity of PPy film. The composite PPy film showed excellent durability in salt spray test. The conductive polypyrrole (PPy) composite film was electrodeposited on copper with BTA or/and silica by cyclic voltammetry in salicylate solution. The corrosion resistance and conductivity of the composite films were evaluated by polarization curves, open circuit potential (OCP) measurements and electrochemical impedance spectroscopy in 5wt% NaCl solution.

Enhanced corrosion resistance and conductivity

It was found that the single doping of benzotriazole (BTA) or silica in PPy films only slightly improved the corrosion resistance, but the Co-doping of BTA and silica in PPy films could significantly improve the corrosion resistance and conductivity of the composite films. Salt spray test (SST) showed that the ternary composite film had the best corrosion resistance and durability, which was attributed to the synergistic effect of silica physical barrier and the active protection of BTA inhibitors.