COMPARISON OF POLYPYRROLE, POLY(3,4-DIMETHYLPYRROLE) AND POLY(3-METHOXY-4-METHYLPYRROLE)

As-grown polypyrrole (PPy), poly(3,4-dimethylpyrrole) (DMPPy) and poly (3-methoxy-4-methylpyrrole) (MMPPy) films doped with p-toluenesulfonat e were characterized. The FT-IR spectra of thick films originate by se lective scattering and should be interpreted as due to a molecular sol id and not to functional group frequencies. Electronic absorption spec tra agree with the polaron-bipolaron absorption model, although for MM PPy strong differences between the energy gap of neutral and doped pol ymers should be taken into account to fulfil the model. DMPPy shows an electrical conductivity dependence of the type sigma=A exp(B/T-1/4), in, higher range of temperatures than PPy and MMPPy.