Morphology and electrical conductivity in polyaniline/polyolefin blends

The effects of processing and molecular composition on the morphology and electrical conductivity of melt pressed polyaniline (PANI)/polyolefin blends have been investigated. In all systems, the morphology was found to consist of two distinct phases, a conducting network of PANI embedded within the thermoplastic host. Low field conductivities ranging from 10^-14 to 10^-4 S/cm could be accessed, through a suitable choice of PANI content and processing conditions. To 200 V/mm, the conductivity of the material was found to increase exponentially with applied field, thereafter remaining close to constant until the onset of breakdown. On further analysis, the applied field E dependence of conduction current i prior to breakdown was found to obey a relationship of the form i=A sinh(bE), as reported in the literature for insulators in the so-called low-field regime. Despite the dramatic variations in electrical properties that result from incorporation of the conducting polymer, the low strain mechanical properties were not degraded to any great degree