A method for the preparation of electrically conductive poly(propylene) -graft-polyacrylic acid/polyaniline (PP-g-PAA/PANI) composite films was developed. The synthesis was mainly performed by two steps, i.e., the surface graft copolymerization of PP films with acrylic acid induced by ultraviolet (UV) and then chemical oxidative polymerization of aniline. The influence of experimental conditions on graft percentage of PANI on PP-g-PAA films was systematically investigated. It was found that when the polymerization on the surface of PP-g-PAA films was performed in aqueous HCl medium, the optimum aniline concentration was 0.1 M at pH 1. Additionally, UV visible spectroscopy and attenuated total reflectance Fourier transform infrared spectroscopy were used to characterize and analyze the interaction between PAA and aniline, the formation mechanism and the surface structure of the PP-g-PAA/PANI films. The morphologies of the PP-g-PAA/PANI composite films were also detected by scanning electron microscope. The conductivity and the thickness of the composite films with 2 wt.% PANI were about 10(-2) S/cm and 0.6 mu m, respectively. (c) 2004 Elsevier B.V. All rights reserved.