Average Deviations in Electrical Conductivity of Poly aniline-Poly (ethylene- co-Vinyl Acetate) Composites as a Novel Characterisation Method

Abstract

It is well known that a slight deviation of experimental conditions during preparation and during conductivity measurements of films, such as conditions of drying, temperature, moisture, etc., may affect the fundamental property of both conducting polymers and their composites, namely their conductivity, resulting in approximate conductivity values and variations in conductivity. In this paper the problem of variations of the conductivity of poly(aniline) - poly(ethylene-co-vinyl acetate) (PANI-EVA) composites was investigated. Three average conductivities (σ̅1, σ̅2, σ̅t) were determined and various average deviations (Δ̅σ1, Δ̅σ2, Δ̅σ1,2, Δ̅σt, G) were also estimated. Changes during the storage of PANI-EVA composites were studied by using both the average conductivities and the average deviations from conductivity. As a result of structural changes in the composites the electrical conductivity of the films increased, i.e. the conductive pathways became more exact, after four months storage of the composites. It was clearly shown that the existence of variations in conductivity is a characteristic feature of PANI- EVA composites studied and describes their evolution. The new method can be helpful and applicable to the structural characterization of other conductive polymer composites as well.