Synthesis and characterization of high molecular weight, highly soluble polypyrrole in organic solvents

Polypyrrole with high solubility (Ppy-DEHS, solubility; 3 similar to 11wt%) in organic solvents (NMP DMSO, DMF, m-cresol, THF, acetic acid, chloroform , dichloromethane, benzene etc.) was chemically synthesized using di(2-ethy lhexyl) sulfosuccinate sodium salt (NaDEHS) as a doping agent. The weight a verage molecular weight (Mw) of Ppy-DEHS appeared to be 62,296 which corres ponds to 303 pyrrole rings in polymer chain. Homogeneous solutions prepared from the various solvents showed different absorption behaviors in the nea r IR region depending on the polarity of the solvent. Electrical conductivi ties (sigma (dc)) of Ppy-DEHS films cast from the various organic solvents were in the range of 10(-4) to 12 S/cm at room temperature. Ppy-DEHS films cast from NMP were stretch-oriented up to 2.5 times (L/Lo=2.5) and their co nductivities reached up to 60 S/cm. The improved solubility in various orga nic solvents was explained with the effect of the non-polar alkyl chain and polar sulfosuccinate group.