Novel conducting polyaniline (PANI)/cyanoresin (Cyan) blends were prepared by the addition of Cyan/dimethylformamide solutions to aniline monomer/dopant solutions and the in situ chemical oxidative polymerization of aniline with ammonium persulfate as an oxidant in aqueous p-toluene sulfonic acid solutions. The PANI/Cyan blends were prepared with various compositions (5:95, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, and 70:30), and blend films of PANI/Cyan were obtained with a casting method. The conductivity of the PANI/Cyan blend films was 10(-7) to 10(-2) S/cm, which was measured by a four-probe technique. The tensile strength of the blend films was maintained with an increasing amount of PANI (up to 50 wt %), and this was attributed to intermolecular interactions such as hydrogen bonding between PANI and Cyan and a reinforcing effect through blending. This hypothesis was corroborated by Fourier transform infrared spectroscopy. Field emission scanning electron microscopy and thermogravimetric analysis were also used to investigate the morphology and thermal properties of the conducting PANI/Cyan blend films, respectively. (c) 2005 Wiley Periodicals, Inc.