The chemical copolymerization of aniline and 2,5-dibromoaniline or 2,6-dibromoaniline by oxidation with K2Cr2O7 in H2SO4/acetonitrile media has been carried out. Copolymer composition can be effectively controlled varying the monomer feed ratio. When substituted aniline fraction is increased in the copolymer, the electrical conductivity (sigma) decreases; this effect is more important when 2,6-dibromoaniline is used. Thus, the conductivity can be controlled in a broad range, from 1.2 to 10(-6)-10(-11) S.cm(-1) depending on the substituted aniline and the feed ratio. The relations between copolymer compositions and comonomer feed molar ratios shows that the aniline is slightly more reactive than dibromoanilines during the copolymerization process. All the copolymers were shown to be more processable than polyaniline. (C) 2003 Kluwer Academic Publishers.