Optimization of Anticorrosive PANi and PPy Synthesis Conditions on ZnNiMo Coated Copper Electrode Surface with Box Behnken Design

The surface of the copper metal was successfully coated with a certain thickness of zinc-nickel-molybdenum (ZnNiMo) alloy by applying the chronopotentiometry technique. Then PANi and PPy homopolymer films were synthesized on the ZnNiMo coated Cu surface (Cu/ZnNiMo) in an aqueous sodium oxalate solution containing molybdate ion at certain concentrations. PANi and PPy film synthesis conditions were modelled by RSM applying Box-Behnken design by using three factors as molybdate ion concentration, monomer concentration and scan rate. Thus, the optimal synthesis conditions of PANi and PPy films on the Cu/ZnNiMo electrode were determined by evaluating anticorrosion performances. It has been determined that the relationship between the corrosion resistance of PANI and PPy films and the studied parameters can be modeled with quadratic and 2FI equations, respectively. The surface diagrams obtained for PPy were very interesting in that they showed that the change in any of the operating parameters reversed the change of the response depending on the other parameters. The anticorrosion properties of PANi and PPy homopolymer films that synthesized at their optimal conditions on Cu/ZnNiMo electrode surface were investigated by the E-ocp-time curves, anodic polarization plots and AC impedance spectroscopy measurement, in 3.5% NaCl solution. PPy and PANi homopolymer films provided significant physical barrier property to Cu/ZnNiMo electrode. Besides, PANi film on Cu/ZnNiMo electrode surface exhibited significantly high more protection behavior in 3.5% NaCl solution than that of PPy.