TECHNOLOGY FOCUS - POLYMERS - Preferred Properties: The cell resistance of the fuel cell at 90degreesC is 0.02-0.25 OMEGA cm2, preferably 0.05-0.2 OMEGA cm2. The value of cell resistance at 20degreesC differs from the cell resistance value at 90degreesC of an amount not higher than 70%, preferably not higher than 50%, with respect to the value of cell resistance at 90degreesC. The amount of drafting of the side chain is 10-250%, preferably 40-230%. The fuel cell is a direct methanol fuel cell or a hydrogen fuel cell.Preferred Polymers: The polyolefin is selected from polyethylene, polypropylene, polyvinylchloride, ethylene-propylene copolymers (EPR) or ethylene-propylene-diene terpolymers (EPDM), ethylene vinyl acetate copolymer (EVA), ethylene butylacrylate copolymer (EBA), polyvinylidenedichloride, polyvinylfluoride (PVF), polyvinylidenedifluoride (PVDF), vinylidene fluoride tetrafluoroethylene copolymer (PVDF-TFE), polyvinylidene-hexafluoropropylene copolymer, chlorotrifluoroethylene-ethylene copolymer, chlorotrifluoroethylene-propylene copolymer, polychloroethylene, ethylene-tetrafluoroethylene copolymer (ETFE), propylene-tetrafluoroethylene copolymer, propylene-hexafluoropropylene copolymer, ethylene-hexafluoropropylene copolymer, preferably polyethylene and low density polyethylene (LDPE).Preferred Method: The side chains are selected from hydrocarbon polymer chain, which contains proton functional groups or optionally modified to provide proton conductive functional groups. The proton conductive functional groups are selected from sulfonic acid group and phosphoric acid group, preferably sulfonic acid groups. The side chains are obtained by graft polymerization of unsaturated hydrocarbon monomers, which are optionally halogenated.Preferred Monomer: The unsaturated hydrocarbon monomer are selected from styrene, chloroalkylstyrene, alpha-methylstyrene, alpha,beta-dimethylstyrene, alpha,beta,beta-trimethylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, alpha-fluorostyrene, trifluorostyrene, p-chloromethylstyrene, acrylic acid, methacrylic acid, vinylalkyl sulfonic acid, divinylbenzene, triallylcyanurate, vinylpyridine, and their copolymers, preferably styrene or alpha-methyl styrene.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Catalyst: The hydroperoxy groups decomposition catalyst used in the grafting step during production of polymer electrolyte membrane, is selected from ferrous sulfate, ferrous ammonium sulfate, cobalt (II) chloride, chromium (III) chloride, copper chloride, preferably ferrous sulfate.Preferred Agent: The grafted side chains are optionally provided with proton conductive functional groups using sulfonating or phosphorating agent. The sulfonating agent is selected from chlorosulfonic acid, fluorosulfonic acid or sulfuric acid. The phosphorating agent is selected from chlorophosphoric acid or fluorophosphoric acid.