PROTON NMR-STUDY OF ROUSE DYNAMICS AND IDEAL GLASS-TRANSITION TEMPERATURE OF POLY(ETHYLENE OXIDE) LICF3SO3 COMPLEXES

A range of low-molecular-weight linear poly(ethylene oxide) chains wit h LiCF3SO3 have been examined via the transverse proton NMR relaxation . From the measured relaxation functions it is shown that the chains o bey Rouse dynamics. This analysis gives the molecular weight of a Rous e statistical subunit and the fundamental Rouse relaxation time. It wa s found that varying the temperature and salt concentration had no eff ect on the size of a Rouse statistical segment and therefore none on t he conformation of the chains. The temperature dependence of the funda mental Rouse relaxation time was found to be well modeled by the Vogel -Tamman-Fulcher equation. The NMR-measured correlation times were then successfully used to predict the glass transition temperature as meas ured by DSC. The main conclusion of this paper is that under the addit ion of salt the ideal glass transition temperature T-0 is found to rem ain constant or indeed to slightly decrease.