Dielectric relaxation and Poole-Frenkel conduction in poly(vinyl chloride) blends with bisphenol A/Egyptian corncob resin

The dielectric constant (epsilon') dielectric loss index (epsilon ''), direct-current conductivity, and current-voltage (I-V) characteristics of pure poly(vinyl chloride) (PVC) and blends of PVC and bisphenol A/Egyptian corncobs (BCC) were investigated at different temperatures. The relaxation processes for PVC and its blends revealed that PVC and BCC had an incompatible phase. PVC blends with 5 wt % BCC exhibited a peculiar I-V behavior. Both epsilon' and epsilon '' were used to study miscibility and phase behavior in blends of PVC. The activation energies of all PVC samples were calculated. At higher voltages, the conduction mechanism could be identified as the Poole-Frenkel type. In addition, the ionic groups of BCC could enhance the PVC conductivity. (C) 2008 Wiley Periodicals, Inc.