ELECTRICALLY CONDUCTIVE SEMIINTERPENETRATING POLYMER NETWORKS OF POLY(3-OCTYLTHIOPHENE)

Electrically conducting, semiinterpenetrating polymer networks (semi-IPNs) were synthesized from soluble poly(3-octylthiophene), styrene monomer, and a cross-linking agent. By controlling the level of cross-linking of the polystyrene component, it was possible to create semi-IPNs with highly dispersed microdomains of the conjugated polymer. For example, semi-IPN samples containing 20% poly(3-octylthiophene) (P3OT) and 10% divinylbenzene (DVB) exhibited very finely dispersed P3OT domains on the order of 1000 angstrom. This particular cross-linking level also produced semi-IPNs with a very low percolation threshold (ca. 3 vol % P3OT). The conductivity stability of FeCl3-doped samples containing 20 % P3OT and cross-linked with 10 % DVB was found to be considerably enhanced, thereby supporting the hypothesis that improved stability in these materials may be achieved by restricting their chain mobility.