Block copolymers of alpha,omega-diamine polydimethylsiloxane (DA center dot PDMS) and polypyrrole have been produced by the polymerization of pyrrole with the redox system of ceric salt/DA center dot PDMS. The properties of the copolymers may be regulated by the ratio of DA center dot PDMS/Pyrrole/Ce-4(NH4)(2)(NO3)(6). The copolymers with lower conductivities are soluble in solvents such as DMF and acetone but higher conductive copolymers are insoluble. A block copolymer with unusually high conductivity (4000 S/cm) was produced under one specific polymerization condition. The chemical structure and the surface morphology of the copolymer particles seem to be important for high conductivity. (c) 2006 Elsevier Ltd. All rights reserved.