Ground tire rubber (GTR) films and GTR particles were surface-functionalized by glycidyl methacrylate and methacrylic acid through photoinitiated grafting. The grafting yield of GTR films was determined by Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). For the calibration of the FTIR-ATR data, X-ray photoelectron spectroscopy was used. The presence of epoxy and carboxyl groups on the GTR surface was demonstrated by contact-angle measurements. (C) 2003 Wiley Periodicals, Inc.