Studies on thermo-acoustic parameters of poly(ethylene glycol)- 400 at different temperatures

The ultrasonic velocity and density have been measured at different temperatures between 299 and 363 K for the pure liquid sample, poly(ethylene glycol) with average molecular mass 400 g mol −1 (PEG 400). From these, isentropic compressibility (β), intermolecular free length ( L f ), acoustic impedance ( Z ), molar volume ( V m ), Schaff’s available volume V a ( s ), molar sound velocity ( R a ), and molar compressibility ( W ) have been evaluated. The variations of these parameters with the temperature of the sample have been studied. Data so obtained are employed to compute other thermodynamic parameters. Variations in various parameters with respect to temperature are discussed in the light of the results obtained.