Industrial polypyrrole electrodeposition on zinc-electroplated steel

Polypyrrole films were electrodeposited on zincated surfaces in a one-step process from aqueous solutions of sodium salicylate and pyrrole. This elect rolyte passivates the substrate and makes it possible to obtain strongly ad herent PPy films with controlled thickness by electrolysis at constant curr ent. With a view to industrial application for rapid polymerization on comm on metals, an aqueous solution of 2 M sodium salicylate and 0.5 M pyrrole a t pH 5 and room temperature provides optimum conditions. Laboratory studies and deposition with a pilot cell show that 2 mum of polymer can be deposit ed in 1 s with a current density of 70 A dm(-2).