The temperature dependence of proton NMR spectra and spin-lattice relaxation in the rotating frame has been studied for Pb(CF3SO3)(2) PEO(n), where PEO is poly(ethylene oxide) (MW = 4 x 10(6)), and n = 3-40. The dynamic properties of the crystalline PEO are not affected when salt is dissolved into the polymer. The chain mobility is, however, highly reduced in the amorphous regions and the mobility is in the same range as in crystalline PEO at room temperature. F-19 NMR studies, spectra, and spin-lattice relaxation in the laboratory frame, suggest a correlation between the anion mobility and the polymer chain mobility, even though the interactions are weak.