Evolution of electrical properties of some conductive polymer composite textiles with organic solvent vapours diffusion

The sensitivity of several conductive polymer composites (CPC) to solvent vapours has been studied. Electrical properties of three CPC poly(amide12-b-tetramethylene oxide)-carbon black (PE-BAX-CB), poly(propylene)-carbon black (PP-CB) and poly(ethylene-co-ethyl acrylate)-carbon black (EEA-CB) were investigated in the presence of four organic solvent vapours, chloroform, toluene, methanol and ethanol. The experiments show that it is possible to use extruded CPC textiles to combine acceptable conductivity for heating and satisfying response for vapour detection. Moreover, the investigation of the mechanisms involved during the solvent vapours diffusion into the CPC, shows that not only the response of the systems DeltaR/R-0 can be used for vapour detection but also the shape of the curves, i.e., the diffusion mode characterised by DeltaR/R-max versus roott curves slope and onset. The diffusion curve shape analysis together with the use of CPC of different chemical nature and structure (comonomer content and crystallinity) is expected to decrease the number of CPC necessary for vapour detection. (C) 2003 Elsevier B.V. All rights reserved.