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

Proton NMR has been used to reveal the effect of adding LiCF3SO3 on bo th the structure and dynamics of poly(ethylene oxide) melts. A range o f molecular weights from unentangled to entangled chains was examined at different salt concentrations. The transverse relaxation was interp reted using recent theoretical models due to Brereton. Short chains we re 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 meas ure the entanglement density, which was shown to be independent of sal t concentration. The main conclusion of this paper is that the salt on ly affects the viscosity experienced by the chain without forming cros s-links.