In-situ production of electrically conductive fibres in polyaniline-SBS blends

Blending of electro-conductive monofilaments with more traditional insulating materials is a promising approach for the production of composites for applications in static dissipative packaging and in industrial textiles. Accordingly, we report on a favourable method for manufacturing these kinds of material which involves generating the fibres in-situ, that is, during the actual forming process. Electrically conductive polyaniline (PANI) was thermally blended with polystyrene-polybutadiene-polystyrene (SBS) at different weight compositions. The resultant blends were capillary extruded in order to induce a drawing process in the dispersed phase (PANI) of the blend and hence, the in-situ formation of PANI fibres within the above mentioned polymeric matrix. Microscopic analysis on the extrudates revealed that PANI was deformed during the process to produce elongated structures, i.e. ellipsoids or even short fibres, in the blends. Electrical measurements were performed and it was found that blending SBS with no more than 20 weight percent of PANI could produce an electrically conductive composite with a good level of conductivity. The relationship between the volume conductivity and content of PANI in the PANI-SBS blends, was found to be characteristic of a percolation system, with a threshold as low as 5 weight percent of PANI. (C) 2000 Kluwer Academic Publishers.