BULK properties of A liquid phase mixture {ETHYLENE GLYCOL+TERT-BUTANOL} in the temperature range 278.15-348.15 K and pressures of 0.1-100 MPa. II. MOLAR ISOTHERMAL COMPRESSIBILITY, MOLAR ISOBARIC EXPANSIBILITY, thermal pressure coefficient, aNd internal pressure
G. I. Egorov, D. M. Makarov
G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo
Keywords: ethylene glycol, tert-butanol, high pressure, molar isothermal compressibility, molar isobaric expansibility, thermal pressure coefficient, internal pressure
Abstract
Based on the experimental data, the molar isothermal compressibilities, molar isobaric expansibilities, thermal pressure coefficients, internal pressures of a liquid phase mixture {ethylene glycol (1) + tert-butanol (2)} are calculated for a wide spectrum of compositions in the range of pressures of 0.1-100 MPa and temperatures of 278.15-323.15 K. Shown that the dependences of molar isothermal compressibilities KT,m , molar isobaric expansibilities EP,m , and isochoric thermal pressure coefficients b on the mole fraction of tert-butanol in the mixture are characterized by the absence of extrema typical of aqueous systems. The manifestation of negative partial expansibility and negative partial expansibility of ethylene glycol in the mixture is found. The thermal pressure coefficients decrease with an increase in the mole fraction of tert- butanol at all pressures and temperatures. A rise in the pressure increases the thermal pressure coefficient, while a rise in the temperature decreases its value due to a decrease of free space in the mixture. An increase in the concentration of tert- butanol leads to an increase in the negative temperature coefficient of internal pressure ΔPint/ΔT, which indicates a weakening of intermolecular interaction at these compositions.
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