Аннотация:It was found that the matrix polymerization of aniline in the presence of sPPO leads to formation of interpolyelectrolyte PANI:sPPO complexes in which polyaniline is in emeraldine state. The presence of sPPO matrix as well as its concentration has a significant influence on the induction period of aniline polymerization and on the yield of PANI. The polymerization mechanism is proposed. Depending on the initial sPPO to aniline molar ratio either soluble (non-stoichiometric) or precipitated (stoichiometric) complexes can be obtained as polymerization products.