Dielectric response and dc conductivity in polyvinylbutyral: An analysis in the complex conductivity plane

Dielectric measurements have been carried out on thin films of polyvinylbut yral in the frequency range from 10 to 10(5) Hz at room temperature. The re sponse was analyzed in terms of a graphical representation in the complex c onductivity plane. Using this representation, a value of the contribution o f dc conductivity on the order of 1.05 x 10(-10) S/m was estimated. This va lue was of the same order as that obtained by complementary current-voltage measurements. The similarity between these two values is an indication tha t in our samples. the contribution to the dc and ac conductivities stems fr om conduction mechanisms of different origins, which confirms that in polar polymers these two contributions can be experimentally separated. since th e dipoles do not contribute to the conduction current. The same behavior wa s observed at different temperatures. These results allow us to conclude th at the representation of dielectric data in the conductivity complex plane provides an alternative to estimating the contribution of a dc conductivity from the dielectric response, without the experimental complication of mea surements at extremely low frequencies.