Synthesis and characterization of thienyl- and terthienyl-group-bearing methacrylic polymers as precursors for grafting reactions of thiophene side-chains

Acrylic and methacrylic monomers bearing pyrrolyl, thienyl and terthienyl g roups, were synthesized and copolymerized with various amounts of butyl acr ylate and butyl methacrylate. In the resulting copolymers the heterocycle s ide-groups behaved as initiators in the oxidative polymerization of thiophe ne, allowing the polythiophene chains to grow from the side-groups and lead ing therefore to graft copolymers. These last were collected mostly as inso luble fractions after extraction with chloroform. Processible polymers with polythiophene side-chains were obtained when in the precursor polymer the heterocycle side-group content was very low. The presence in the graft copo lymers of a significant number of stiff polythiophene side-chains was respo nsible for the rise in Tg values in comparison with the precursor polymers. The average number of grafted thiophene units, evaluated in the range 2-7. 5, did not relate directly to measured conductivity values that were in the range 5.9 x 10(-5)-6.2 x 10(-2) Scm(-1). (C) 1999 Society of Chemical Indu stry.