GAS-TIGHT MODIFIED PERFLUOROSULPHO-CATIONITE MEMBRANE AND METHOD OF PRODUCING SAID MEMBRANE Russian patent published in 2011 - IPC C08J5/22 H01M8/10 C08J3/02 C08L27/12 C08L81/06 C08L29/04 C08K3/10 C08K3/22 C08K3/32 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing gas-permeable membranes which can be used in fuel cells at high operating temperature (100°C and higher, methanol fuel cells, low- and high-pressure water electrolysis cells etc). The membrane is made from a copolymer of tetrafluoroethylene with perfluorosulpho-containing vinyl ether and a tertiary modifying perfluorinated comonomer - perfluoro-2-methylene-4-methyl-1,3-dioxalane or perfluoroalkylvinyl ether containing 1 or 3 carbon atoms in the alkyl, and a polymeric or inorganic modifier. The method of making the membrane involves contacting a perfluorosulpho-cationite membrane with a liquid composition containing an ion-exchange perfluorosulpho-polymer, a polymeric or inorganic modifier and a solvent. The perfluorosulpho-polymer with functional sulpho-groups SO₃M, where M is a hydrogen, ammonium or alkali metal ion, has equivalent mass of 800-900, and is similar on structure to the membrane polymer. Contacting is carried out at 18-80°C. Particles of the modifier are formed on the surface or inside the membrane at 18-120°C.

EFFECT: preserving proton conductivity, preventing cathode polarisation and water flooding, high energy density of fuel cells.

12 cl, 3 tbl, 41 ex