MEMBRANE FOR SEPARATION OF METHANE-CONTAINING GAS MIXTURE AND METHOD OF ITS PRODUCTION Russian patent published in 2019 - IPC B01D67/00 B01D71/32 C08F214/26 C08F234/02 C08F34/00 

FIELD: chemistry.

SUBSTANCE: invention relates to synthesis of a perfluorinated polymer of polyperfluoro(2-methyl-2-ethyl-1,3-dioxole) to create a gas-separation membrane based thereon. Membrane for separation of methane-containing mixture of gases contains polyperfluoro(2-methyl-2-ethyl-1,3-dioxole) as polymer. Method of producing a membrane comprises obtaining a perfluorodioxole-based polymer, dissolving the obtained polymer in a fluorine-containing solvent, watering the formed solution onto a substrate, evaporating the solvent and separating the obtained membrane from the substrate. Polymer of polyperfluoro(2-methyl-2-ethyl-1,3-dioxol) is obtained by polymerisation of perfluoro(2-methyl-2-ethyl-1,3-dioxole) at pressure of 800–1200 MPa and temperature of 50–60 °C. Solvent used is a fluorine-containing aromatic solvent. Dissolution of the obtained polymer is carried out until concentration of solution is 3–5 wt. %. Polymer is obtained without using radical polymerisation initiators. Obtained membrane can be used for separation of methane-containing mixture of gases. Invention enables to obtain a membrane which exceeds foreign analogues by selectivity (1.15 times higher than selectivity for a pair of He/CH₄ for Teflon AF2400 - prototype at simplicity and efficiency of its production) and, at the same time, membrane permeability is kept practically at the same level.

EFFECT: polymer synthesis without using radical polymerisation initiators eliminates the need for complex purification of the polymerisation product, which simplifies and reduces the cost of obtaining a membrane.

2 cl, 5 dwg, 3 tbl, 4 ex