POLYIMIDE-POLYBENZOXAZOLE COPOLYMER, METHOD OF PRODUCING SAID COPOLYMER AND GAS-SEPARATION MEMBRANE CONTAINING SAID COPOLYMER Russian patent published in 2012 - IPC C08G61/12 C08G73/10 C08G73/22 B01D71/64 B01D53/22 

FIELD: chemistry.

SUBSTANCE: present invention relates to a polyimide-polybenzoxazole copolymer, a method of producing said copolymer and a gas-separation membrane containing said copolymer. The polyimide-polybenzoxazole copolymer is a compound of formula: , where values of radicals Ar₁, Ar₂, Ar₃, Ar'₂, Ar'₃, Q, m and n are given in the claim. The method of producing the polyimide-polybenzoxazole copolymer involves heat treatment of a polyimide-polyhydroxyimide copolymer at 150-500°C for a period ranging from 5 minutes to 12 hours. Said copolymer exhibits excellent gas-permeability and gas-selectivity and is therefore suitable for use in gas-separation membranes of different forms, such as films, fibres or hollow fibres.

EFFECT: obtained gas-separation membranes can withstand aggressive conditions such as prolonged use, acidic conditions and high moisture owing to a hard polymer backbone chain present in the copolymer.

38 cl, 4 tbl, 14 dwg, 7 ex