Synthesis of a siloxane polymer with pyrrole end groups has been described. Electrochemical block polymerization of pyrrole through these end groups has been achieved. Characterization of the electrolytic products has been performed by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetry analysis (TGA) analyses and FT-IR studies. The effects of different dopant ions, namely, p-toluene sulfonic acid (PTSA) and tetrabutylammonium tetrafluoroborate (TBAFB), in electropolymerization and conductivities of the corresponding block copolymers have been investigated. (C) 1998 Elsevier Science S.A. All rights reserved.