ABSORPTION-SPECTRA OF THERMALLY AGED POLY ANILINE FILMS

The absorption spectra of polyaniline thin films have been measured as a function of heating temperature. Two absorption peaks were observed at 600 nm (quinoid structure) and 300 nm (benzenoid). A blue shift of the 600 nm peak took place with increasing temperature. While the 300 nm peak remained unchanged below 190-degrees-C, a blue shift was obse rved in the temperature range from 190-degrees-C to 306-degrees-C, whe re the intensity of the quinoid absorption relative to that of the ben zenoid decreased. The UV-visible and infrared spectroscopies implied t he crosslinking reactions assisted by oxygen.