Poly(m-aminophenyl acetic acid) was synthesized under different conditions from the respective monomer, using ammonium persulfate as oxidizing agent in both the presence and the absence of CuCl2 in HCl(aq). Moreover, the copolymers between aniline and m-aminophenyl acetic acid were prepared at several feed mol ratios (f(1)) of aniline. Copper was introduced by the Batch method in the homo- and copolymers of different compositions. The polymers were characterized by FTIR and UV-vis spectroscopy, elemental analysis, thermal analysis, and electrical conductivity. The thermal stability and the content of copper increased as the content of aniline was increased in the copolymers. Moreover, the copolymers showed a high thermal stability; at 400degreesC a weight loss < 10% was observed. The electrical conductivity was increased with a higher content of aniline in the copolymers, achieving semiconduction values. (C) 2003 Wiley Periodicals, Inc.