Electrohydrodynamic synthesis of polypyrrole coated polyurethane colloidal dispersions using the electrocatalyst Tiron

Nitrate doped polypyrrole (PPy) was coated onto polyurethane (PU) colloids using electrohydrodynamic processing. Optimal yields for formation of the PPy/NO3/PU colloids were obtained using a polymerisation potential of 0.60 V, a flow rate of 40 ml min−1, and a PU concentration of 4% w/v. Synthesis of PPy/Tiron/PU colloids was accomplished using similar conditions to those used to prepare PPy/NO3/PU colloids. However, the reaction proceeded at a considerably faster rate (due to the fact that Tiron is an effective electrocatalyst for PPy formation), giving a comparable yield of colloid in a shorter time. The UV–vis spectra of films cast from PPy/Tiron/PU colloids were more typical of conducting PPy than films obtained from PPy/NO3/PU colloids.