In a 0.5 mol•dm－3 sulfuric acid medium, cyclic voltammograms of m-toluidine and its corresponding in situ UV-Vis spectra indicate that the poly(m-toluidine) film was produced on the surface of the electrode. Under the condition of potentiostatic electrolysis, the electropolymerization of m-toluidine on an indium-tin oxide (ITO) conductive glass electrode was studied in detail by in situ UV-Vis spectrometry. It was showed that m-toluidine could be electropolymerized on the ITO electrode only under the condition of higher electrolysis potential and lager concentration of the monomer. At 0.2 mol•dm－3 of m-toluidine, 0.7 V (vs. saturated Ag/AgCl) and 20 mmol•dm－3 of m-toluidine, 0.9 V (vs. saturated Ag/AgCl), in situ UV-Vis spectrometry indicated that the polymerization did not happen whereas the low molecule weight oligomer such as dimers could be produced on the ITO electrode. The obvious induction period was observed when elctropolymerization of m-toluidine was performed in the 200 mmol•dm－3 m-toluidine at 0.8 V (vs. saturated Ag/AgCl). Furthermore, in situ UV-Vis spectra showed that the electrocopolymerization between m-toluidine and p-phenylenediamine was performed. The p-phenylenediamine might react with m-toluidine to yield more active intermediates, which not only promote polymerization but also accelerate polymerization. In addition, through that p-phenylenediamine could be incorporated into copolymer to make the copolymer have a phenazine or phenazine like cyclic structure, which was proved by the FTIR of polymers.

Key words: m-toluidine, p-phenylenediamine, electrocopolymerization, UV-Vis spectrometry, FTIR