Emulsion polymerization pathway for preparation of organically soluble polyaniline sulfate

In this work, aniline was polymerized directly to polyaniline sulfate salt without using protic acid. Polyaniline sulfate salt was prepared by an emulsion polymerization pathway using surfactants such as anionic surfactant (sodium lauryl sulfate), cationic surfactant (cetyltrimethylammonium bromide) and non-ionic surfactant (polyethylene glycol octadecyl ether). Anionic/cationic surfactants yield polyaniline sulfate salt in organic phase and non-ionic surfactant yields polyaniline sulfate in powder form. The dopant, i.e. sulfate ion, in polyaniline sulfate salt was generated from ammonium persulfate which was used to oxidize aniline. Ammonium persulfate acts both as an oxidizing agent and as a doping agent in the polymerization process of aniline to polyaniline sulfate salt. The spectral and electrical properties of the polyaniline salt synthesized by the emulsion polymerization pathway are compared with those of the polyaniline salt prepared by an aqueous polymerization pathway using sulfuric acid as protic acid.