Synthesis, characterization and biocompatibility studies of oligosiloxane modified polythiophenes

This paper describes the preparation and characterization of homopolymers of 3-oligo(dimethylsiloxane)thiophene macromonomers, V-VIII, and copolymers with 3-methylthiophene. The thiophene macromonomers were prepared by hydrosilylation reaction between co-(Si-H)-oligo(dimethylsiloxane), I-IV, and 3-propenylthiophene using a platinum-divinyltetramethyldisiloxane complex as the catalyst. The products were characterized by H-1, C-13, Si-29 NMR and IR spectroscopy; DSC (differential scanning calorimetry) and GPC studies. Two distinct glass transition temperatures are observed for poly[VIII], a T-g at -79 degreesC corresponds to the soft oligo(dimethylsiloxane) phase and the T-g at 190 degreesC corresponds to the hard thiophene backbone. Homopolymers of V and VI, and copolymers may be doped with 12 to generate electronic conductive material, a copolymer of poly[V]-co-poly[3-methylthiophene] (50/50, w/w) has an electronic conductivity value of 5 x 10(-5) S/cm. at 25 degreesC. The polymers are tractable and may be molded into thin films; a number of the polymers are soluble in organic solvents. Polythiophene modified with oligosilioxanes are biocompatibile; the polymers minimally interfere with the growth of HeLa cells. (C) 2003 Elsevier Science Ltd. All rights reserved.