Densities, ultrasonic speeds, excess and partial molar properties of binary mixtures of 2-pyrrolidone with isomeric propanediols at temperatures from 303.15 K to 323.15 K

Abstract

The densities, ρ and speeds of sound, u of the binary mixtures of 2-pyrrolidone with 1,2-propanediol and 1,3-propanediol, including those of pure liquids, have been measured over the entire range of composition at temperatures, (303.15–323.15) K and atmospheric pressure. Using the experimental data, excess molar volumes, VmE, excess isentropic compressibility, κsE, excess speeds of sound, uE and excess molar isentropic compressibility, Ks,mE were calculated. The partial molar volumes, V¯m,1 and V¯m,2, partial molar isentropic compressibilities, K¯s,m,1 and K¯s,m,2, excess partial molar volumes, V¯m,1E and V¯m,2E and excess partial molar isentropic compressibilities, K¯s,m,1E and K¯s,m,2E over whole composition range; partial molar volumes, V¯m,1° and V¯m,2°, partial molar isentropic compressibilities, K¯s,m,1° and K¯s,m,2°, excess partial molar volumes, V¯m,1°E and V¯m,2°E and excess partial molar isentropic compressibilities, K¯s,m,1°E and K¯s,m,2°E of the components at infinite dilution have also been calculated. The results have been discussed in terms of intermolecular interactions prevailing in these mixtures. The results indicated that the interactions in these systems follow the order: 1,2-propanediol>1,3-propanediol. The speeds of sound of these mixtures have been analysed by using scaled particle theory and the results are compared with experimental findings.