Effect of the doping medium on blends of polyurethane and polyaniline

Flexible and free-standing films from blends of polyurethane, based on cast or oil, and polyaniline were obtained with various compositions by casting. Significant increase on conductivity followed by a considerable decrease o n doping time was obtained by doping the films in N,N-dimethylformamide (DM F) solution with p-toluene sulphonic acid (TSA) or HCl instead of the conve ntional doping in aqueous solution. This doping efficiency is proposed to b e due to an improved swelling of the blend structure caused by the solvent. The electrical conductivity increases significantly upon polyaniline conte nt increase reaching 10(-2) S/cm for a polyaniline content of about 10% (w/ w).