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Stability, including thermal stability, conductivity stability in air and after thermal treatment (100 -200°C), of the polyaniline (PANI) films synthesized by a doping-dedoping-redoping method was investigated. It was found that thermogravimetric analysis (TGA) curves undergo three steps: loss of water or solvent, dedoping and decomposition, and those depend on the counterions. Compared with PANI films doped with camphor sulfonic acid (CSA) in m-cresol, the thermal stability of the doped PANI films is improved by the new method, and thermal stability in the order of PANI-H 3 PO 4 Ͼ PANI-p-TSA Ͼ PANI-H 2 SO 4 Ͼ PANI-HCl, PANI-HClO 4 Ͼ PANI-CSA was observed. The conductivity of the doped PANI films at room temperature was reduced after thermal treatment, and it is dependent of the counterions. It was found that the conductivity stability of PANI-p-TSA and PANI-CSA is the best below 200°C. When the doped PANI films were placed in air, their conductivity decrease slowly with time due to deproton, and also depends on the counterions.

Polypyrrole (PPy) was successfully prepared by chemical oxidation in various anionic surfactant solvents and an interesting regulation of the molar ratio of the oxidant and the monomer was firstly discovered which was closely related to the conductivity of the PPy when the molar ratio of the anionic surfactant to the monomer was 0.3. The value of conductivity reached its maximum when the molar ratio of the oxidant and the monomer was 1.1. A series of testing results including scanning electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Four‐Point Probes Resistivity Measurement System showed that the morphology and conducting characteristic of obtained PPy were greatly influenced by the anionic surfactant. The doping level and the degree of the structural order of counterions in the polymer chains influence the conductivity of the obtained doped PPy. POLYM. ENG. SCI., 53:2465–2469, 2013. © 2013 Society of Plastics Engineers