Excess molar volumes and viscosities of binary liquid mixtures of (polyether plus ester) systems at 298.15, 308.15, and 318.15 K

Excess molar volumes, V-m(E) and viscosities (eta) for the binary liquid mi xtures of ((polyether + methyl) acetate (C3H6O2), ethyl acetate (C4H8O2), a nd propyl acetate (C5H10O2)) have been measured as a function of compositio n at the temperatures of 298.15, 308.15, and 318.15 K and atmospheric press ure over the full range of composition. The polyethers were 2,5,8-trioxanon ane, and 2,5,8,1 1-tetraoxadodecane, From these results deviations of the v iscosity, ar from a mole fraction average, and excess free energies of acti vation of viscous flow, DeltaG*(E) have been calculated. The results for V- m(E), Delta eta, and DeltaG*(E) are discussed in terms of the molecular int eractions between the components of the mixtures. Furthermore, activation e nthalpies (DeltaH*) and entropies (DeltaS*) of viscous flow have been evalu ated and their variation with concentration is discussed. (C) 2001 Elsevier Science B.V. All rights reserved.