type of alkyl halide 1 iodo pentane as before the reaction was conducted in a molar excess of the alkyl halide and allowed to proceed for 24 hours in a dry box once again a rubbery film was obtained another n type reduced polyacetylene film was prepared as described above and this time reacted with a branched alkyl halide 2 bromo pentane again the reaction was conducted in a molar excess of alkyl halide and allowed to continue for 24 hours in a dry box the reaction again yielded a rubbery film another polyacetylene film was prepared in accordance with the method described above in example 1 and was again reduced with sodium naphthalenide to render it a n type conductor in this example an 8 carbon chain alkyl halide 1 bromo octane was employed to graft octyl functional groups onto the radical anion sites of the polyacetylene as before the reaction was conducted in a molar excess of the alkyl halide and the resulting film was again deformable and swellable each of the films obtained in examples 1 5 were doped by exposing the substituted polymer to a vapour stream of iodine carried in deoxygenated and dried argon the doped polymers were subsequently subjected to a dynamic vacuum 10 5 torr for 24 hours to remove adsorbed iodine conductivity measurements were.