Effect of temperature on poly(ethylene oxide) chains in aqueous solution. A viscometric, 1H NMR and Raman spectroscopic study

Abstract

A combination of viscometry, Raman scattering and 1H NMR measurements has been used to study the effect of temperature changes on the properties of solutions of poly(ethylene oxide) in H2O or D2O. The viscosity data show that the overall dimensions of the polymer chains decrease with increasing temperature, while the Raman spectra indicate a simultaneous decrease in chain helicity. Polymer 1H NMR spin–lattice relaxation times in D2O are consistent with a mechanism in which small segments of the chain reorient at a rate controlled by the solvent viscosity up to a temperature of ca. 80 °C.