EFFECT OF TEMPERATURE ON POLY(ETHYLENE OXIDE) CHAINS IN AQUEOUS-SOLUTION - A VISCOMETRIC, H-1-NMR AND RAMAN-SPECTROSCOPIC STUDY

A combination of viscometry, Raman scattering and H-1 NMR measurements has been used to study the effect of temperature changes on the prope rties of solutions of poly(ethylene oxide) in H2O or D2O. The viscosit y data show that the overall dimensions of the polymer chains decrease with increasing temperature, while the Raman spectra indicate a simul taneous decrease in chain helicity. Polymer H-1 NMR spin-lattice relax ation times in D2O are consistent with a mechanism in which small segm ents of the chain reorient at a rate controlled by the solvent viscosi ty up to a temperature of ca. 80 degrees C.