Abstract: The present invention relates to membrane electrode units (MEU) for high temperature fuel cells having an improved stability and a process for their manufacture.

Abstract: A process for producing thermally surface postcrosslinked water-absorbing polymer particles, wherein the water-absorbing polymer particles are coated before, during or after the thermal surface postcrosslinking with at least one complex consisting of a polyvalent metal salt and a 2-hydroxycarboxamide.

Abstract: Proton-conducting polymer electrolyte membrane based on a polyazole salt of an inorganic or organic acid which is doped with an acid as electrolyte, wherein the polyazole salt of the organic or inorganic acid has a lower solubility in the acid used as electrolyte than the polyazole salt of the acid used as electrolyte, a process for producing the inventive proton-conducting polymer electrolyte membrane, a membrane-electrode assembly comprising at least two electrochemically active electrodes which are separated by a polymer electrolyte membrane, wherein the polymer electrolyte membrane is a proton-conducting polymer electrolyte membrane according to the invention, and a fuel cell comprising at least one membrane-electrode assembly according to the invention.

Abstract: A process for preparing mechanically stabilized polyazoles, comprising the following steps: I) treating at least one polyazole having at least one amino group in a repeat unit with a solution comprising (i) at least one strong acid and (ii) at least one stabilizing reagent, the total content of stabilizing reagents in the solution being in the range from 0.01 to 30% by weight, II) performing the stabilization reaction directly and/or in a subsequent processing step by heating to a temperature greater than 25° C., the stabilizing reagent used being at least one polyvinyl alcohol. The polyazoles thus obtainable are notable especially for a high conductivity and a very good mechanical stability. They are therefore especially suitable for applications in fuel cells.

Abstract: A method for the production of a mechanically stabilized polyazole polymer membrane or film having the following steps: a) providing a membrane or film containing i.) a polyazole with at least one amino group in a repeating unit except the ones obtained by reacting aromatic and/or heteroaromatic diaminocarboxylic acids, ii.) at least one strong acid and iii.) at least one stabilizing reagent, the total content of stabilizing reagents in the membrane or film being within the range of from 0.01 to 30% by weight, b) performing the stabilization reaction in the membrane, immediately or in a subsequent processing step of the membrane, c) optionally doping the membrane obtained in accordance with step b) with a strong acid or concentrating the present strong acid by removal of present water, wherein the stabilizing reagent contains at least one oxazine-based compound and wherein the polyazole polymer has at least 1.8 dl/g intrinsic viscosity.

Abstract: The present invention relates to membrane electrode units (MEU) for high temperature fuel cells having an improved stability and a process for their manufacture.

Abstract: The present invention relates to a novel proton-conducting polymer membrane based on polyazole polymers which, owing to their outstanding chemical and thermal properties, can be used widely and are suitable in particular as polymer electrolyte membrane (PEM) for producing membrane electrode assemblies or so-called PEM fuel cells.

Abstract: The present invention relates to a novel proton-conducting polymer membrane based on polyazole polymers which, owing to their outstanding chemical and thermal properties, can be used widely and are suitable in particular as polymer electrolyte membrane (PEM) for producing membrane electrode assemblies or so-called PEM fuel cells.

Abstract: Composition in the form of a solution and/or dispersion, comprising: at least one polyazole with an intrinsic viscosity, measured in at least 96% by weight sulfuric acid, in the range from 3.0 to 8.0 g/dl, and orthophosphoric acid (H3PO4) and/or polyphosphoric acid, wherein the polyazole content, based on the total weight of the composition, is in the range from 0.5% by weight to 30.0% by weight, the H3PO4 and/or polyphosphoric acid content, based on the total weight of the composition, is in the range from 30.0% by weight to 99.5% by weight, the H3PO4 and/or polyphosphoric acid concentration, calculated as P2O5 (by acidimetric means), based on the total amount of H3PO4 and/or polyphosphoric acid and/or water, is in the range from 70.5% to 75.45%. Additionally protected are particularly advantageous processes for preparation and for use of the inventive composition.

Abstract: A process for preparing a polyazole with an inherent viscosity, measured in at least 96% sulfuric acid at 25° C., greater than 2.9 dl/g, comprising the steps of i) mixing one or more aromatic tetraamino compounds with one or more aromatic carboxylic acids or esters thereof which comprise at least two acid groups per carboxylic acid monomer, or mixing one or more aromatic and/or heteroaromatic diaminocarboxylic acids, in polyphosphoric acid to form a solution and/or dispersion ii) heating the mixture from step i) under inert gas to temperatures in the range from 120° C. to 350° C. to form the polyazole, wherein in step ii), a mixture having a concentration of polyphosphoric acid, calculated as P2O5 (by acidimetric means), based on the total amount of H3PO4, polyphosphoric acid and water in the mixture, greater than 78.

Abstract: A process for producing thermally surface postcrosslinked water-absorbing polymer particles, wherein the water-absorbing polymer particles are coated before, during or after the thermal surface postcrosslinking with at least one complex consisting of a polyvalent metal salt and a 2-hydroxycarboxamide.

Abstract: The invention relates to a process for preparing mechanically stabilized polyazole polymers. The process includes the steps of: a) producing a film comprising polyazoles with at least one amino group in a repeat unit, b) treating the film from step a) with a solution comprising (i) at least one acid and (ii) at least one stabilizing reagent, and c) performing the stabilization reaction in the membrane obtained in step directly or in a subsequent membrane processing step by heating to a temperature greater than 60° C. The stabilizing reagent contains at least one compound which has at least one aldehyde group and at least one hydroxyl group; or at least one hemiacetal group; or at least one acetal group. These polyazole polymer membranes have a high conductivity and a good mechanical stability and are suitable for applications in fuel cells.

Abstract: A process for preparing mechanically stabilized polyazoles, comprising the following steps: I) treating at least one polyazole having at least one amino group in a repeat unit with a solution comprising (i) at least one strong acid and (ii) at least one stabilizing reagent, the total content of stabilizing reagents in the solution being in the range from 0.01 to 30% by weight, II) performing the stabilization reaction directly and/or in a subsequent processing step by heating to a temperature greater than 25° C., the stabilizing reagent used being at least one polyvinyl alcohol. The polyazoles thus obtainable are notable especially for a high conductivity and a very good mechanical stability. They are therefore especially suitable for applications in fuel cells.

Abstract: The invention relates to a process for preparing mechanically stabilized polyazole polymers. The process includes the steps of: a) producing a film comprising polyazoles with at least one amino group in a repeat unit, b) treating the film from step a) with a solution comprising (i) at least one acid and (ii) at least one stabilizing reagent, and c) performing the stabilization reaction in the membrane obtained in step directly or in a subsequent membrane processing step by heating to a temperature greater than 60° C. The stabilizing reagent contains at least one compound which has at least one aldehyde group and at least one hydroxyl group; or at least one hemiacetal group; or at least one acetal group. These polyazole polymer membranes have a high conductivity and a good mechanical stability and are suitable for applications in fuel cells.

Abstract: A method for the production of mechanically stabilized polyazole polymers, comprising the following steps: a) providing a membrane comprising i.) polyazoles with at least one amino group in a repeating unit except the ones obtainable by reacting aromatic and/or heteroaromatic diaminocarboxylic acids, ii.) at least one strong acid and iii.) at least one stabilizing reagent, the total content of stabilizing reagents in the membrane being within the range of from 0.01 to 30% by weight, b) performing the stabilization reaction in the membrane, immediately or in a subsequent processing step of the membrane, c) if appropriate, additionally doping the membrane obtained in accordance with step b) with a strong acid or concentrating the present strong acid further by removal of present water, wherein the stabilizing agent comprises at least one oxazine-based compound. The polyazole polymer membranes thus obtainable are in particular characterized by a high conductivity and a very good mechanical stability.

Abstract: The invention relates to a membrane electrode assembly which comprises two gas diffusion layers, each contacted with a catalyst layer, which are separated by a polymer-electrolyte membrane. Said polymer electrolyte membrane has an inner area which is contacted with a catalyst layer, and an outer area which is not provided on the surface of a gas diffusion layer. The inventive assembly is characterized in that the thickness of all components of the outer area is 50 to 100%, based on the thickness of all components of the inner area. The thickness of the outer area decreases over a period of 5 hours by not more than 5% at a temperature of 80° C. and a pressure of 5 N/mm2. The decrease in thickness is determined after a first compression step which takes place over a period of 1 minute at a pressure of 5 N/mm2.

Abstract: A process for preparing a polyazole with an inherent viscosity, measured in at least 96% sulfuric acid at 25° C., greater than 2.9 dl/g, comprising the steps of i) mixing one or more aromatic tetraamino compounds with one or more aromatic carboxylic acids or esters thereof which comprise at least two acid groups per carboxylic acid monomer, or mixing one or more aromatic and/or heteroaromatic diaminocarboxylic acids, in polyphosphoric acid to form a solution and/or dispersion ii) heating the mixture from step i) under inert gas to temperatures in the range from 120° C. to 350° C. to form the polyazole, wherein in step ii), a mixture having a concentration of polyphosphoric acid, calculated as P2O5 (by acidimetric means), based on the total amount of H3PO4, polyphosphoric acid and water in the mixture, greater than 78.

Abstract: Composition in the form of a solution and/or dispersion, comprising: at least one polyazole with an intrinsic viscosity, measured in at least 96% by weight sulfuric acid, in the range from 3.0 to 8.0 g/dl, and orthophosphoric acid (H3PO4) and/or polyphosphoric acid, wherein the polyazole content, based on the total weight of the composition, is in the range from 0.5% by weight to 30.0% by weight, the H3PO4 and/or polyphosphoric acid content, based on the total weight of the composition, is in the range from 30.0% by weight to 99.5% by weight, the H3PO4 and/or polyphosphoric acid concentration, calculated as P2O5 (by acidimetric means), based on the total amount of H3PO4 and/or polyphosphoric acid and/or water, is in the range from 70.5% to 75.45%. Additionally protected are particularly advantageous processes for preparation and for use of the inventive composition.

Abstract: An aromatic polyether sulfone block copolymer comprises hydrophilic segments which have sulfonic acid groups and hydrophobic segments which have no sulfonic acid groups, wherein the proportion by weight of hydrophilic segments is from 0.02 to 0.35.

Abstract: A process for preparing mechanically stabilized polyazoles, comprising the following steps: I) treating at least one polyazole having at least one amino group in a repeat unit with a solution comprising (i) at least one strong acid and (ii) at least one stabilizing reagent, the total content of stabilizing reagents in the solution being in the range from 0.01 to 30% by weight, II) performing the stabilization reaction directly and/or in a subsequent processing step by heating to a temperature greater than 25° C., using at least one high-functionality polyether as the stabilizing reagent. The polyazoles thus obtainable are notable especially for a high conductivity and a very good mechanical stability. They are therefore especially suitable for applications in fuel cells.