DYNAMIC PROPERTIES OF AQUEOUS-SOLUTIONS OF ETHYLENE-GLYCOL OLIGOMERS AS MEASURED BY THE PULSED GRADIENT SPIN-ECHO NMR TECHNIQUE AT 25-DEGREES-C

Self-diffusion coefficients for binary systems containing water and an oligomer of ethylene glycol [HO-(CH2CH2-O)(n)H, n = 1-5], have been m easured at 25 degrees C in the whole concentration range by the pulsed gradient spin-echo NMR technique. Upon adding oligomer to pure water, both the oligomer and water self-diffusion coefficients decrease unti l a certain composition is reached, after which they remain approximat ely constant. This evidence is interpreted in terms of molecular inter actions, especially hydrogen-bond formation. A relation between mutual and self-diffusion coefficients for these systems is found and commen ted upon.