Correlation between dielectric relaxation and d.c. electrical conduction in polypyrrole family of polymers

Abstract

The dielectric constant ɛ′ (ω) of polypyrrole, poly(N-methyl pyrrole) and their copolymer, poly(N-methyl pyrrole-pyrrole), has been measured in the frequency range 100 Hz–100 kHz and in the temperature range 77–350 K. The d.c. conductivity has also been measured in the temperature range 77–350 K. The static dielectric constant (ɛ0) and relaxation frequency (R have been estimated from the dielectric constant data. The estimation of site spacing (d) suggests that the charge carrier localization is about per 4–8 pyrrole rings. An attempt has been made to establish a correlation between dielectric relaxation and d.c. electrical conduction in these systems and it has been found that both originate from the same hopping process.