Electrical and thermal behavior of gamma-phase poly(vinylidene fluoride)/NaY zeolite composites

Abstract

Poly(vinylidene fluoride), PVDF, based composites with increasing NaY zeolite content up to 32 wt.% have been processed by solvent casting and melt crystallization. Depending on the melting temperature of the polymer, the composite crystallizes in the electroactive gamma or non electroactive a-phase of the polymer. The dielectric constant at room temperature reaches values larger that 1000 for the 32 wt.% composite at 1 kHz and it is mainly attributed to restricted ion mobility and interfacial polarization effects due to the zeolite inclusion, leading also to high dielectric losses. For the higher zeolite concentrations the composite d.c. electrical conductivity is characterized by two conducting regimes separated by a concentration independent breaking voltage of 4 V, which is associated to an intrazeolite charge transport.