Semiconductive polymers were obtained by soaking nylon-6/6,9 particles in concentrated CuCl(2)(.)2H(2)O aqueous solutions, followed by reduction of the treated particles with sodium borohydride aqueous solutions. The reduced nylon-6/6,9/CuCl2 particles were compression molded at a relatively low temperature (160degreesC). The bulk volume resistivity obtained is at an intermediate level, similar to10(5) ohm-cm. The compounds generated by reduction of the nylon-6/6,9/CuCl2 particles were determined to consist of metallic copper by means of energy-dispersive X-ray micro-analysis. The metallic copper is responsible for the electrical conductivity of the bulk samples. Samples stored at the ambient atmosphere gradually absorb oxygen and moisture, resulting in a decrease in the conductivity. The morphology of nylon-6/6,9/CuCl2 samples before and after reduction was studied by a scanning electron microscope and transmission electron microscope. A two-level hierarchy structure, submicrometer and nano-sized, of copper particles was observed, forming the conducting copper networks. Molded samples of reduced nylon-6/CuCl2 and nylon-6,6/CuCl2 particles, prepared by the same procedure as that of nylon-6/6,9/CuCl2 particles, were insulating, whereas a reduced nylon-6/CuCl2 film was moderately conductive. (C) 2004 Wiley Periodicals, Inc.