METHOD FOR PRODUCTION OF ULTRAFILTRATION HEAT-RESISTANT POLYMER MEMBRANE Russian patent published in 2009 - IPC B01D71/64 B01D71/62 

FIELD: technological processes.

SUBSTANCE: invention is related to technology for production of ultrafiltration (UF) heat-resistant polymer membranes, in particular membranes on the basis of compositions of poly-(4,4'-oxydiphenylene)pyromellitimide with cyclised polyacrylonitrile. In method for membrane production, solution of poly-(4,4'-oxydiphenylene)pyromellitimide acid in amide dissolvent is complemented with calculated amount of dry modified polyacrylonitrile. Then glycerin is added as pore forming substance. Modified polyacrylonitrile is prepared with partial chemical cyclisation of linear polyacrylonitrile. Produced forming solution is mixed and degassed. Using draw plate with controlled gap, layer of forming solution is applied onto glass plate. Plate is submerged into water-alcohol setting bath. Formed membrane is transferred to solution of high-boiling technical oil in organic dissolvent, dried and heated up to 250-300°C to achieve complete imidisation of polyamide acid.

EFFECT: invention provides for technologically simple production of UF polymer membranes, which are characterised with water permeability coefficient of Q=(5-300)·10^-6 m/sec atm, rated molecular mass of retention M_L=(10-350)·10³ g/mole, heat resistance of at least 400°C, absence of dissolubility and swelling in all regular organic dissolvents, including amide ones, chemical resistance in aqueous acid mediums, high temperature of durable operation of membranes, which makes 200-300°C.

3 cl, 2 dwg, 2 tbl, 6 ex