Ionic conductivity and dielectric relaxation in poly[(phenyl glycidyl ether)-co-formaldehyde]

Ionic conductivity data and structural relaxation times for poly(phenyl glycidyl ether)-co-formaldehyde (PPGE) are compared for the supercooled liquid under a wide range of temperatures and pressures. Conformance to the fractional Debye–Stokes–Einstein (fDSE) relation was observed under all conditions. The fDSE exponent, = 0.81, provides an estimate of the relative magnitude of the activation volumes for conductivity and dielectric relaxation. The smaller activation volume for the former suggests less free volume is necessary to accommodate ion diffusion in the PPGE than that required for dielectric relaxation. We also fit the combined temperature and pressure dependences of both the conductivity and relaxation times to the Avramov equation.