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Physical–chemical data on the liquid–solid phase transitions in the binary systems trans-perfluorodecalin (trans-PFD)–cis-perfluorodecalin (cis-PFD), trans-PFD–perfluorobutylcyclohexane (BCH), and cis-PFD–BCH are obtained. All three systems are characterized by the presence of a temperature extremum on the fusibility curve. For the trans-PFD–BCH system, the liquidus line can be described by the equation for simple eutectic systems with the assumed activity coefficient = 1, which indicates that the behavior of the system is close to ideal. The process of bulk crystallization is considered using the example of a cis‑PFD–BCH mixture. It is demonstrated that from cis-PFD–BCH mixtures with an initial content xcis-PFD = 0.7348 and 0.6447 mol. fr., cis-PFD can be isolated with a purity of more than 0.99 mol. fr. in three crystallization cycles. [ABSTRACT FROM AUTHOR]

New physicochemical data for trans-perfluorodecalin (trans-PDF) and cis-perfluorodecalin (cis-PFD) are presented. Based on the differential scanning calorimetry, the temperature and heat of the solid−liquid phase transition are determined. The coefficients of Antoine's equation are calculated based on the experimental temperature–pressure dependence data. This article also presents data on the rheological properties («zero» shear viscosity and apparent activation energy for the viscous flow) of the studied compounds. The dependencies of refractive index and excess volume (density) on temperature are studied. Gas chromatography–mass spectrometry data and FTIR, 13C NMR, and 19F NMR spectra are provided. The dependencies are given for the perfluoro(butylcyclohexane) (BCH)–trans-PFD, BCH–cis-PFD, and trans-PFD–cis-PFD binary systems and BCH–trans-PFD–cis-PFD ternary system: refractive index and density (liquid molar volume and excess molar volume) of composition and temperature. The dependences of the excess molar volume on the composition and temperature of the mixtures are correlated with Redlich-Kister and Kohler equations. [ABSTRACT FROM AUTHOR]

The process of perfluoro(7-methylbicyclo[4.3.0]nonane) (MBCN) purification from an industrial mixture of decalin or naphthalene fluorination products is considered. According to experimental data, distillation separation allows us to concentrate MBCN to a fraction with the target-component content of more than 0.950 wt. fr., after which the process efficiency begins to decrease quickly; upon reaching a concentration of 0.975 wt. fr., separation practically breaks down (the value of the separation coefficient → 1). The process of purification of MBCN by the method of heteroazeotropic distillation using acetone (Aс) as a separating agent is proposed, the process being realized on a batch semi-industrial distillation column. The method makes it possible to intensify significantly the final stage of purification and to increase the MBCN content from 0.950 to more than 0.998 wt. fr., the mass fraction of the enriched fraction sampling comprises more than 0.85 of the load and the product yield being above 88%. The values of the separation coefficients between the distillate and the bottom product and the coefficients of enrichment for the target and impurity components are given; for the MBСN–Aс binary system, data on the liquid–liquid phase equilibrium and heteroazeotrope characteristics are determined. [ABSTRACT FROM AUTHOR]

The process of crystallization separation of an industrial mixture of perfluorinated cycloalkanes was considered. The content of target products, cis- and trans-isomers of perfluorodecalin (PFD), in all initial fractions of the investigated samples of the reaction mixture was at least 70 wt.%. Based on the experimental data, the dependences of the crystallization (partition) coefficients between the solid and mother liquor ( D s / l ), the enrichment factor (ηs), and the separation factor (Fs) on the ratio of trans-PFD to cis-PFD, the ratio of mother liquor to solid, and crystallization temperature in the range −50–15 °C were obtained. It was shown that the values D s / l and ηs depended significantly on the concentration of trans-PFD in the initial solution, and that the value of Fs decreased as the process temperature rose. [ABSTRACT FROM AUTHOR]

The purification of perfluoro(7-methylbicyclo[4.3.0]nonane) industrial fractions with a component content above 0.950 in mass fraction is not effective and requires the use of special separation methods. According to experimental data, the separation factor of the initial mixture during distillation with no additional substances is close to 1. At the same time, the addition of acetone (Ac) makes it possible to significantly intensify the process. Ac allowed for obtaining MBCN with a purity higher than 0.998 in mass fraction in one separation cycle, and the degree of recovery was more than 0.85 by weight. The paper presents data on the distribution of components (target product, identified and unidentified impurities of electrochemical fluorination of decalin) between the distillate and bottom product fractions, separation factor, liquid–liquid phase equilibrium in the MBCN-Ac system, and characteristics of the MBCN-Ac heteroazeotrope. [ABSTRACT FROM AUTHOR]

The purification of perfluoro(7-methylbicyclo[4.3.0]nonane) industrial fractions with a component content above 0.950 in mass fraction is not effective and requires the use of special separation methods. According to experimental data, the separation factor of the initial mixture during distillation with no additional substances is close to 1. At the same time, the addition of acetone (Ac) makes it possible to significantly intensify the process. Ac allowed for obtaining MBCN with a purity higher than 0.998 in mass fraction in one separation cycle, and the degree of recovery was more than 0.85 by weight. The paper presents data on the distribution of components (target product, identified and unidentified impurities of electrochemical fluorination of decalin) between the distillate and bottom product fractions, separation factor, liquid–liquid phase equilibrium in the MBCN-Ac system, and characteristics of the MBCN-Ac heteroazeotrope.

The process of crystallization separation of an industrial mixture of perfluorinated cycloalkanes was considered. The content of target products, cis- and trans-isomers of perfluorodecalin (PFD), in all initial fractions of the investigated samples of the reaction mixture was at least 70 wt.%. Based on the experimental data, the dependences of the crystallization (partition) coefficients between the solid and mother liquor (Ds/l), the enrichment factor (ηs), and the separation factor (Fs) on the ratio of trans-PFD to cis-PFD, the ratio of mother liquor to solid, and crystallization temperature in the range −50–15 °C were obtained. It was shown that the values Ds/l and ηs depended significantly on the concentration of trans-PFD in the initial solution, and that the value of Fs decreased as the process temperature rose.