Isobaric heat capacity of the binary liquid (water + 1,2–propanediol) mixtures at high-temperatures and high-pressures

摘要: Abstract Isobaric heat capacity, C P , of binary aqueous 1,2 − propanediol solutions have been measured over the temperature range from room 298.15 K to 473.15 K at pressures up 30 MPa using differential scanning calorimeter (DSC, ITS-400). The measurements were performed for three concentrations 0.0731, 0.1914, and 0.4153 mol fraction 1,2 − propanediol. expanded uncertainty capacity ( ), pressure (P), (T), concentration (x) 95% confidence level with a coverage factor k = 2 is estimated be 2.4%, 0.05%, 15 mK, 0.0001, respectively. T x data used calculate excess molar capacities Pm E ) mixture. second derivatives specific volume or curvature Vm-T isobars calculated dependence along isotherms as ∂ 2 V m / Px = - 1 Tx . Some unusual behaviour in low (below 0.2 mol fraction, dilute mixture) each isotherms-isobars was found.