SHEAR VISCOSITIES OF BINARY-LIQUID MIXTURES - 2-PYRROLIDONE WITH 1-ALKANOLS

Excess viscosities, excess volumes, and free energies of activation for viscous flow of the binary mixtures 2-pyrrolldone + methanol, + ethanol, + 1-propanol, + 1-butanol, and + 1-pentanol were calculated at five different temperatures from density and viscosity measurements. The results obtained suggest that the breaking of the self-associations existing in the pure liquids is partly balanced by the heteroassociations formed among the molecules of the binary mixtures. These heteroassociations decrease with decreasing temperature and increasing chain length of the alcohol. The small excess volumes calculated denote weak interactions, in accordance with the different shape and size of the mixing molecules.