INSITU INTERNAL-REFLECTION FTIR STUDIES ON POLYMERIZATION OF POLYPHENYLENE

Electrochemical polymerization, involving simultaneous doping of polyphenylene was studied with the in situ internal reflection FTIR spectroscopic technique. The main purpose of this work was to study the structure of the polymer grown under different electrochemical circumstances. Galvanostatic and potentiostatic polymerization was used to grow polyphenylene on a Ge substrate. FTIR spectra were recorded during polymerization of films with the final thicknesses of 0.5-5 mum. Only the inner layer of the film, the interface working electrode/polymer film, was studied. From the series of spectra taken, vibrations from doping anions as well as from the corresponding cations of the electrolyte salt could be detected. Vibrations from the polymer indicated a complex structure consisting of crosslinked short chains and oligomers in which the phenyl rings are ortho, meta and para substituted. The current densities used for polymerization was found to have no influence on the coupling of phenyl rings.