A novel method for preparing electrically conductive polypropylene-graft-polyacrylic acid/polyaniline (PP-g-PAA/PANI) composite films was developed. 1,4-Phenylenediamine (PDA) was introduced on the surface of PP-g-PAA film, and then, chemical oxidative polymerization of aniline on PP-g-PAA/PDA film was carried out to prepare PP-g-PAA/PANI electrically conductive composite films. After each step of reaction, the PP film surface was characterized by attenuated total reflectance Fourier transform infrared spectroscopy. Static water contact angles of the PP, PP-g-PAA, and PP-g-PAA/PANI films were measured, and the results revealed that graft reactions took place as expected. The morphology of the PP-g-PAA film and the PP-g-PAA/PANI composite film were observed by atomic force microscopy. The conductivity and the thickness of the PP-g-PAA/PANI composite films with 1.5 wt % PANI were around 0.21 S/cm and 0.4 mu m, respectively. The PANI on the PP-g-PAA/PANI film was reactivated and chain growing occurred to further improve the molecular weight of PANI. (c) 2006 Wiley Periodicals, Inc.