Polymerization of pyrrole and processing of the resulting polypyrrole as blends with plasticised PVC

Polypyrrole was synthesized by chemical oxidation of pyrrole in water conta ining various sulphonic acids like toluene sulphonic acid (TSA), sulphosali cylic acid (SSA), and camphor sulphonic acid (CSA), as well as a combinatio n of each sulphonic acid with sodium dodecyl benzene sulphonate (NaDBS) to investigate the effect of doping on conductivity, yield, and processability of the conducting polymer. Free-standing blend films of polypyrrole and pl asticized polyvinyl chloride (PVC) were obtained by casting an homogeneous suspension of the two polymers in tetrahydrofuran. The maximum conductivity of the blend film is similar to 0.3 S/cm, corresponding to a weight fracti on of 0.16 w/w polypyrrole. The blend film is semiconducting in the range 3 00-10 K. A TG-DTA scan indicates the blend film to be amorphous with a step wise decomposition process similar to pristine PVC. The choice of a dual do pant system during synthesis and the plasticised polymer during subsequent processing were keys to obtaining homogeneous high-quality films. (C) 2001 John Wiley & Sons, Inc.