POLYIMIDE MEMBRANES FROM POLYMERISATION SOLUTIONS Russian patent published in 2015 - IPC B01D71/64 B01D67/00 C08G73/10 

FIELD: chemistry.

SUBSTANCE: invention relates to polyimide membranes which can be either flat membranes or membranes made of hollow fibres. The polyimide membranes can be porous membranes in the form of micro-, ultra- or nanofiltration membranes or nonporous membranes used to separate gases. A method of producing polyimide membranes includes steps of producing a polyimide via polycondensation of an aromatic dianhydride of tetracarboxylic acid with an aromatic diisocyanate in an aprotic dipolar solvent, preparing a polyimide-containing moulding solution and producing a polyimide membrane from the moulding solution, wherein the polyimide is not separated between the first two steps in the form of a solid substance and is not dissolved again, and wherein the membrane is made using a phase inversion technique.

EFFECT: invention enables to obtain membranes having good mechanical properties, pressure resistance during operation and selectivity to different gases.

15 cl, 3 dwg, 5 tbl, 22 ex