Density of water - 2-pyrrolidone mixture a new vibrating tube densimeter from (278.15–323.15) K and up to 70 MPa

Volumetric Properties of Binary Liquid Mixtures of Water with N-Methylpyrrolidone at (278.15–323.15) K and up to 70 MPa

“…This made it possible to calculate the volumetric characteristics at an infinite dilution of NMP in water for the studied state parameters, which had not previously been studied for this system. The paper also compares the volumetric characteristics of aqueous mixtures of NMP and pyrrolidone, which we previously studied under the same state parameters . This work continues our early studies of the volumetric properties of aqueous solutions of amides with various types of intermolecular interactions depending on the composition, temperature, and pressure. − …”

“…The concentration dependence of V m E shows a maximum reduction in the volume of the mixture in the region of x 2 equal to 0.4. The minimum value of V m E at 298.15 K and atmospheric pressure equal to −1.0 × 10 –6 m 3 mol –1 is more negative than V m E for the water–2-pyrrolidone mixture (−0.57 × 10 –6 m 3 mol –1 ) . This indicates that the -CH 3 substitution at the ring nitrogen atom leads to a significant weakening of the self-association of NMP in water.…”

“…Figure shows V 2 E , ∞ as a function of pressure at various temperatures. Also shown in this figure are values of V 2 E , ∞ for 2-pyrrolidone in water at 323.15 K, which were calculated from the data of our earlier work . The transfer of NMP molecules from their own environment to an environment of water molecules at atmospheric pressure results in a significant reduction in volume that is almost independent of temperature.…”

“…The cell temperature was measured using a built-in platinum resistance thermometer with a DMA 4500 display. The details about the experimental setup and the operating method that was used in our laboratory have been described in previous work . The calibration was performed by using water and toluene following the procedure described in a previous article .…”

“…The details about the experimental setup and the operating method that was used in our laboratory have been described in previous work . The calibration was performed by using water and toluene following the procedure described in a previous article . The IAPWS-95 formulation was used to calculate the density of water.…”