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Smotrov M. P., Umetchikov V. A., Danilina V. V., Cherkasov D. G. Phase Equilibria and Component Solubility in the Binary System Water + Dipropylamine. Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology, 2018, vol. 18, iss. 4, pp. 378-382. DOI: https://doi.org/10.18500/1816-9775-2018-18-4-378-382


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544.344.2:544.344.012-013-016:544.344.015.32-33
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Russian

Phase Equilibria and Component Solubility in the Binary System Water + Dipropylamine

Abstract

Dipropylamine is one of the promising antisolvents for extractive salt crystallization, but its solubility in water and phase equilibria in its aqueous solutions over a wide temperature range has not been studied in detail until now. The review of the literature shows that the water-dipropylamine system is classified as a self-separating system with a lower critical solution temperature (LCST). We used the visual-polythermal method in a –25–90°C range to study phase equilibria in the binary system water-dipropylamine and to plot the phase diagram of the system. A detailed study of phase states has revealed that the separation below –1.9°C takes place in overcooled mixtures of water and dipropylamine, i.e. it is nonequilibrium. On the part of the binodal curve that is in the metastable region, the coordinates of the lower critical solution temperature were evaluated by the phase volume ratio method: LCST = –4.7°С, 27.2 wt.% of dipropylamine. It was established for the first time that a non-invariant monotectic equilibrium takes place in the system at –1.9°C, whose solid phase is ice crystals. It was found for the first time that water and dipropylamine form the compound 2(C3H7)2NH·H2O congruent melting at –15.6°C. At –20.4°C, the system has a eutectic equilibrium, whose solid phases are ice and the chemical compound 2(C3H7)2NH·H2O.

References

1. Hobson R. W., Hartman R. J., Kanning E. W. A Solubility Study of Di-n-propylamine // J. Am. Chem. Soc. 1941. Vol. 63. P. 2094‒2095.

2. Stephenson R. M. Mutual Solubility of Water and Aliphatic Amines // J. Chem. Eng. Data. 1993. Vol. 38. P. 625‒629.

3. Степанова Э. И., Кухаренок И. С., Куражева А. В., Харисов М. А. Исследование фазового равновесия жидкость–жидкость в системе пропанол–вода–дин-пропиламин при 30°C // Журн. прикл. химии. 1988. Т. 61. С. 1180‒1181.

4. Nagata I., Meyer T., Gmehling J. Correlation of binary liquid-liquid equilibrium data over a wide temperature range using UNIQUAC and extended UNIQUAC models // Fluid Phase Equilibria. 1991. Vol. 65. P. 19‒39.

5. Góral M., Shaw D. G., Maczynski A., Wisniewska-Gocłowska B., Oracz P. IUPAC-NIST Solubility Data Series. 96. Amines with Water. Part 1. C4–C6 Aliphatic Amines // J. of Phys. and Chem. Ref. Data. 2012. Vol. 41, № 4. P. 043106 (40 p.).

6. Химическая энциклопедия : в 5 т. / гл. ред. И. Л. Кнунянц. М. : Сов. энцикл., 1988–1998.

7. Аносов В. Я., Озерова М. И., Фиалков Ю. Я. Основы физико-химического анализа. М. : Наука, 1976. 504 с.

8. Трейбал Р. Жидкостная экстракция : пер. с англ. / под ред. С. З. Кагана. М. : Химия, 1966. 724 с.

9. Алексеев В. Ф. О взаимной растворимости жидкостей // Горн. журн. 1879. Т. 4, № 10. С. 83‒114.

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