Dielectric spectroscopy of blends of polyvinylalcohol and polypyrrole

Polymeric blends composed of conducting polypyrrole chains dispersed in a matrix of polyvinylalcohol containing ferric chloride represent a class of materials whose electrical behavior is intermediary between those of insulating and conducting polymers. To investigate the transport and polarization characteristics of these films we examine in this work their dielectric relaxation spectrum in the frequency domain. A relaxation in frequency identified in the resistance-reactance diagram is followed as a function of the relative concentration of the two polymers, as different types of dopants are used to promote the conducting behavior of polypyrrole. We also analyze the change in the relative dc and ac contributions to the total conductivity of the samples as the amount of incorporated polypyrrole is increased. (C) 2003 American Institute of Physics.