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Article

Thermophysical Properties of Materials
2022. V. 60. № 4. P. 485–491
Lazarev S.I., Golovin Yu.M., Kovalev S.V., Konovalov D.N., Kotenev S.I.
Thermal, X-ray diffraction, and kinetic characteristics of filtration films in the study of ethereal substances
Annotation
This paper presents the results of the evolution of the structure of filtration films of the MFFC-3 and PP-190 types in the process of purification of ethereal substances. It has been established by thermogravimetry that a decrease in the mass of samples of working films for MFPC-3 by 22%, and for PP-190 by 18%, which is a at temperatures of 130265C, is due to the destruction of the polymer molecules of the drainage layer as a result of transmembrane pressure and diffusion of ethereal substances. For a pure MFFC-3 membrane sample, a single thermal effect is recorded at the peak melting temperature Tmax=247С, typical for lavsan with melting enthalpy ΔH=40 kJ/kg, and for the working sample at Tmax=249C with ΔH=19 kJ/kg. For a clean sample of the pre-filter PP-190, a single thermal effect is recorded at the peak melting temperature Tmax=160C with ΔH=68 kJ/kg, and for the working sample at Tmax=157C with ΔH=67 kJ/kg. The bulk crystallinity of the MFFC-3 and PP-190 films of the working samples decreased by 52 and 33%, respectively, in relation to the initial ones, according to the data of differential scanning calorimetry. X-ray diffraction data indicate changes in the microstructure of films of working samples in the intergranular amorphous phase as a result of deformation of lamellar crystallites, while the X-ray degree of crystallinity of the MFPC-3 film decreased by 12%, and that of PP-190 by 9%. On the dependence curves of the hydrodynamic permeability of MFFC-3 and PP-190 filtration films on time at different transmembrane pressures, four characteristic periods are noted, where gel clots are formed on the MFFC-3 membrane, which significantly affect the process of baromembrane separation and the PP-190 pre-filter becomes clogged.
Article reference:
Lazarev S.I., Golovin Yu.M., Kovalev S.V., Konovalov D.N., Kotenev S.I. Thermal, X-ray diffraction, and kinetic characteristics of filtration films in the study of ethereal substances, High Temp., 2022. V. 60. № 4. P. 485