Graft polymerization of methacrylic acid (MAA) onto polytetrafluoroethylene (PTFE), initiated by the mixed solution of alkyllithium/hexamethylphosphoramide (HMPA) at low temperature, was studied. Using electron spin resonance (ESR), nuclear magnetic resonance, X-ray photoelectron and vibrational (infrared) spectroscopies, the chemical structure of the grafted poly(methacrylic acid) (PMAA) onto the PTFE (PTFE-g-PMAA) was investigated. The grafted PMAA was found to be located deeper than 2.5 nm from the surface of the PTFE. The molecular motion of the PTFE-g-PMAA was also studied by means of the temperature-dependent ESR spectra of the spin-labeled PTFE-g-PMAA. The results suggested that the molecular motion of the grafted PMAA chain was mainly controlled by that of the principal PTFE chain, and the evaluated activation energy was lower for the grafted PMAA chain (e.g., 6.5 kJ/mol at temperature range below 295 K) than that for the PMAA homopolymer (13.2 kJ/mol). (C) 2004 Wiley Periodicals, Inc.