A series of styrene-phenyl vinyl sulfoxide diblock copolymers was prepared using the ’living’ anionic polymerization technique. The thermally labile phenyl vinyl sulfoxides undergo an elimination process to yield acetylene moieties at 150-degrees-C. The weight and volume of the iodine-doped conducting fractions were adjusted by changing the length of the styrene block. A sigmoidal composition-dependent conductivity and a maximum in the dielectric constant measurement near the threshold composition suggested a ’percolation-like’ conducting process. In addition to electrical measurement, the block copolymers were also characterized by infra-red spectroscopy, thermal analysis, H-1 n.m.r., and size exclusion chromatography.