NMR-STUDY OF POLY(ETHYLENE OXIDE) COMPLEXES WITH LICF3SO3

Proton NMR has been used to reveal the effect of adding LiCF3SO3 on both the structure and dynamics of poly(ethylene oxide) melts. A range of molecular weights from unentangled to entangled chains was examined at different salt concentrations. The transverse relaxation was interpreted using recent theoretical models due to Brereton. Short chains were shown to undergo Rouse dynamics with salt merely altering the local monomer friction coefficient and not influencing the structure of the melt. From the higher molecular weight chains it was possible to measure the entanglement density, which was shown to be independent of salt concentration. The main conclusion of this paper is that the salt only affects the viscosity experienced by the chain without forming cross-links.