Inverse emulsion polymerization for high molecular weight and electrically conducting polyanilines

The polyanilines were synthesized via an inverse emulsion polymerization path at 0 °C or room temperature using ammonium peroxydisulfate (APS) as oxidant and dodecylbenzene sulfonic acid (DBSA) as surfactant and dopant simultaneously for the resulting polyanilines. The influence of polymerization temperature, organic continuous phase type (xylene or hexane) and APS/aniline molar ratio on the polyaniline properties was investigated. Polyaniline–DBSA precipitates prepared at 0 °C showed high conductivity in the range of 1.0–4.0 S/cm. Polyanilines in emeraldine base form prepared at 0 °C and APS/aniline molar ratio of 0.4 had high intrinsic viscosities of 191 and 202 ml/g using xylene and hexane as the organic continuous phase of emulsion system, respectively. The polyaniline–DBSA precipitates obtained from the polymerization system using xylene as the organic continuous phase possessed nice fibrillar morphology.