DIELECTRIC-CONSTANTS OF ACETONITRILE, GAMMA-BUTYROLACTONE, PROPYLENE CARBONATE, AND 1,2-DIMETHOXYETHANE AS A FUNCTION OF PRESSURE AND TEMPERATURE

The dielectric constants epsilon of 1,2-dimethoxyethane, acetonitrile, gamma-butyrolactone, and propylene carbonate were determined from cap acitance measurements extrapolated to infinite frequency; In epsilon a re reported as a function of pressure up to 80 MPa at 15, 25, 35, 45 d egrees C and as a function of temperature in the range 10 to 500C at 0 .10133 MPa. The variation of In epsilon with temperature or pressure c an be expressed by a second order polynomial expression. The isotherma l compressibilities beta of the solvents were determined at 25 degrees C from sound velocities, densities, and heat capacities. A simple cor relation can be established between partial derivative ln epsilon/part ial derivative P and beta for most aprotic solvent.