DYNAMIC-MECHANICAL BEHAVIOR OF ELECTROCHEMICALLY SYNTHESIZED POLYPYRROLE FILMS

Dynamical mechanical spectrometry experiments were performed on polypy rrole films to provide some information on the microstructure through the analysis of the molecular motions in the material. Various polypyr roles doped with different aromatic anions (benzene sulfonate, p-tolue ne sulfonate, 2-naphthalene sulfonate and anthraquinone-2 sulfonate) h ave been analysed in the - 150 to 250 degrees C temperature range. Two mechanical relaxations have been detected. A low-temperature relaxati on, located at about -60 degrees C at 1 Hz for all the analysed films, is due to the motion of water molecules sorbed in the polymer. The se cond relaxation is located at a higher temperature between 118 and 214 degrees C according to the nature of the dopant. It could result from polymer backbone motions. It has been related to the polypyrrole glas s transition.