A study of conducting organic charge transfer complexes and their incorporation into insulating polymers.

Polymers have long been regarded as excellent electrical insulators. Over the past two decades, polymers that have good electrical (and thermal) conductivity have gained considerable interest. They fall into two broad categories, composites of electrically conducting materials with insulating polymers, and polymers that have been chemically treated (doped) rendering them conductive by charge transfer within the polymer structure. Both forms of material possess disadvantages, low percolation thresholds and poor mechanical properties. The early doped polymers tended to be environmentally unstable, while composites tend to have poor mechanical properties.An extensive review of conducting polymers is presented, covering filled polymers and theories proposed for their electrical conduction. Elastomeric and polymeric ionene polymers, polymer/TCNQ materials, and reticulate doped polymers are reviewed.The practical study undertaken here concerned the production of conducting polymer composites by reticulately doping insulating polymers with organic, solvent soluble, charge transfer complexes of bis-pyridinium and trimethyl sulphonium iodide, 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) salts.The TCNQ salts were synthesised and characterised using elemental analysis, uv/vis spectrophotometry, variable magnetic susceptibility, electrical conductivity, and powder X-Ray diffraction. The salts were solvent blended with appropriate insulating polymers and cast to form the conducting reticulate film polymers. A study of the resulting charge transfer complex morphology was made.