Pristine polymers, trans-polyacetylene

Pristine polyacetylene is a typical organic semiconductor irrespective of its cis-trans content. The room-temperature conductivity measured by a conventional two-probe method and the energy gap determined by equation 19 are 1 x 10 S cm and 0.56 eV for 92.5% trans-polymQv, and 4 x 10" Scm and 0.93 eV for 80.0% cw-polymer, respectively In equation 19 (T is the electrical conductivity at T and ACg is the energy gap... 

The advantages of the Durham route are (1) contaminating catalyst residues can be removed because the precursor polymers are soluble and can be purified by dissolution and reprecipitation and (2) the precursors can be cast as films or drawn and oriented prior to conversion to the all-trans form of polyacetylene. This allows a degree of control over the morphology of the final product which in the pristine state appears to be fibrous and disordered. Because conductivity increases by alignment of the polymer chains, stretching the film or fiber assists this process and this can be performed using the prepolymer. 

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