A STUDY ON THE ELECTROCHEMICAL POLYMERIZATION OF POLYPARAPHENYLENE USING BENZENE AND BIPHENYL AS STARTING MATERIAL

Polymer films of poly-p-phenylene (PPP) were electrochemically synthesized using both monomer (benzene) and dimer (biphenyl) as starting material in Li- or tetrabutylammonium-tetrafluoroborate or tetrabutylammonium-percholate (0.1 M) in different solvents. Polymerization was performed either potentiostatically or galvanostatically using both anodic and cathodic polarization of the working electrode in a three-electrode one-compartment cell. ITO-glass, Pt, GC and Au were used as electrode material. Electrochemical properties of the PPP-films were studied by cyclic voltammetry and characterized by ir-spectrometric analysis. The thickness of the films were estimated from the charge consumed during polymerization. The role of different parameters in the electrosynthesis of the PPP-films was studied and the electrochemical behaviour of the films thus obtained was compared with each other. Using biphenyl as starting material the film was formed easier due to its lower oxidation potential. Ir-spectrometric analysis showed that the product with both starting materials consists of both para- and ortho-linked monomer units. It was also possible to grow PPP-films by cathodic polymerization.