Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Volumetric properties of N-methyl-2-pyrrolidone (NMP) binary mixtures with .gamma.-butyrolactone (GBL) and propylene carbonate (PC) are calculated from the experimental densities and reported in the temperature range from (293.15 to 323.15) K and at atmospheric pressure (0.1 MPa) over the whole composition range. The excess molar volumes have positive values in the whole concentration range in the case of (NMP + PC) binary mixture, with maximum value at equimolar composition, indicating weaker interactions between the components after the mixing. Two extreme VE values are observed in (NMP + GBL) system: maximum at x(NMP) = 0.4 and minimum at x(NMP) = 0.9. Negative VE values in NMP-rich region are the consequence of the better geometrical fit of the molecules. The excess properties of (NMP + GBL) and (NMP + PC) binaries are analyzed using Prigogine Flory Paterson theoretical model. An excellent agreement between experimental and theoretical values at equimolar composition is observed. Apparent molar volumes and thermal expansion coefficients are also calculated. Viscosity measurements of the pure components and NMP binary mixtures with GBL and PC were performed in the temperature range from (298.15 to 323.15) K. Using obtained experimental viscosities several semi-empirical equations and models were tested.