POLYIMIDE COPOLYMERS AND MEMBRANES, METHODS FOR MANUFACTURE AND USE THEREOF, AS WELL AS SYSTEMS AND METHODS FOR PURIFYING GASEOUS HELIUM Russian patent published in 2025 - IPC C08G73/10 B01D71/64 

FIELD: chemistry.

SUBSTANCE: present invention relates to a polyimide random copolymer, a method for production thereof, a membrane made from said polyimide copolymer, a method of producing a membrane, as well as a system for purifying gaseous helium and a method for purifying gaseous helium. Polyimide random copolymer is a compound of formula: , in which m and n are integer from 10 to 2000; X is a structure of formula: , in which R⁵ and R⁶ in each case independently represent H, optionally substituted C1-C4-alkyl group or optionally substituted C6-C10-aryl group; Y represents a structure selected from a group consisting of formula , in which R⁷ and R⁸ in each case independently represent H, an optionally substituted C1-C4-alkyl group or an optionally substituted C6-C10-aryl group, and ipticene-based structures; Z and Z' in each case are independently selected from a group consisting of an ipticene-based structure and an optionally substituted formula: .

EFFECT: membranes, in particular hollow fiber membranes made from the polyimide copolymer according to the present invention, have excellent permeability properties and/or selectivity with respect to gases, in particular with respect to helium and/or hydrogen; besides, obtained polyimide random copolymer exhibits other useful properties, including such as thermal stability, mechanical stability, chemical resistance, as well as membrane-forming properties.

20 cl, 9 dwg, 12 tbl, 6 ex