NOVELTY - Blend and a blend membrane comprises low-molecular hydroxymethylene-oligo-phosphoric acid (I) and a polymer.    USE - The membrane is useful: for producing energy in electro-chemical method; as a component of fuel cells membrane (hydrogen- or direct methanol-fuel cell) at -20 to 180 degrees C; in electro-chemical cells; in secondary batteries; in electrolysis cells; and in membrane separated process and gas separation, pervaporation, perstraction, reverse osmosis, electrodialysis and diffusion dialysis (claimed).    ADVANTAGE - The blend exhibits high strength of phosphoric acid group, high concentration of phosphoric acid group. The blend suppresses the condensation of the phosphoric acid group. The blend ensures maximum proton conductivity under reduced humidification and at up to 180 degrees C.    DETAILED DESCRIPTION - Blend and a blend membrane comprises low-molecular hydroxymethylene-oligo-phosphoric acid of formula (R-C(PO3H2)x(OH)y) (I) and a polymer.    R = organic group or polymer containing a cation exchanger groups or a non-ionic precursor of SO2X, POX2, COX, basic group including primary, secondary or tertiary amino group, imidazole group, pyridine group, pyrazole group and/or OH-group;    X = hal, OH, OMe, NR1R2, OR1;    Me = any metal cation or transition metal cation, including ZrO2+ or TiO2+, or ammonium cation;    R1, R2 = H or aryl- or alkyl residue;    x = 2; and    y = 1.    INDEPENDENT CLAIMS are included for:    (1) a polymer modified with (I) that is obtained by reacting polymer, the carboxylic acid group or carboxylic acid halide group-COHal, with phosphite compound or by reacting polymer aldehyde with phosphoric acid ester under amine catalyst, under the oxidation of the intermediate hydroxyphosphoric acid with manganese dioxide or one of the other oxidizing agent;    (2) preparing an ionic cross-linked blends from 1-hydroxymethylene-1,1-bisphosphonic acid (II) containing a pyridine group and a sulfonated aryl main chain polymer, comprising dissolving the sulfonated aryl main chain polymer in the salt form in a dipolar-aprotic solvent including dimethyl sulfoxide (DMSO) to 1-20% solution, dissolving a basic group containing (II) in the sodium ion (Na+)-form in DMSO to 1-20% solution, combining both the solution, discharging the combined solution on a glass plate to a thin film, removing the solvent at 50-150 degrees C and optionally under pressure of 800-10 mbar by evaporation, removing the polymer film from the glass plate in the presence of water, subsequently treating the developed polymer: (a) in 0.1-50% of base (alkaline lye such as sodium hydroxide, potassium hydroxide, lithium hydroxide etc., alkaline-earth lye like barium hydroxide, calcium hydroxide, aqueous ammonia or aqueous primary, secondary or tertiary amines or quaternary ammonium salts) at temperatures of 0-100o?C for 1-480 hours, (b) in 0.1-90% of mineral acid (hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid) at 0-100 degrees C for 2-480 hours, (c) in de-mineralized water at 0-100 degrees C for 2 seconds to 480 hours; (d) in 0.1-10 molar zirconium oxychloride solution at 0-100 degrees C for 2-480 hours, (e) in de-mineralized water at 0-100 degrees C for 2 seconds to 480 hours, (f) in 0.1-90% of phosphoric acid at 0-100 degrees C for 2-480 hours, (g) in de-mineralized water at 0-100 degrees C for 2 seconds to 480 hours;    (3) preparing a covalent cross-linked blend from an aryl-1-hydroxymethylene-1,1-bisphosphonic acid and a polymer containing hydroxyl-group, comprising dissolving the polymer in a dipolar aprotic or in a protic solvent e.g. DMSO, dissolving the low-molecular aryl-1,1-hydroxymethylene-1,1-bisphosphonic acid in the same solvent, either in proton-form or in Na+-form, providing the cross-linker e.g. glutaraldehyde, for dissolving the low-molecular 1-hydroxymethylene-1,1-bisphosphonic acid, combining both the solutions, discharging the combined solution on a glass plate to a thin film, removing the solvent at 50-150 degrees C and optionally at low pressure of 800-10 mbar by evaporation, removing the polymer film from the glass plate in the presence of water, subsequently treating the polymer film in (a)-(g);    (4) preparing a polymer with (II) from carboxylated polymers, comprising converting the carboxylic acid groups of carboxylated polymers with thionyl-chloride to carboxylic acid chloride groups, dissolving the polymer acid chloride in an ether solvent, e.g. tetrahydrofuran or a diethyl-ether, to 0.1-5% solution, pouring the obtained solution in a silylated, dried 2000 ml glass bulbs under argon, and cooling down under argon at 0 to -78 degrees C, subsequently injecting tris(trimethylsilyl)phosphite (per milliequivalent acid chloride 1 millimole tris(trimethylsilyl)phosphite) over a septum under intensive stirring, stirring for 1 minutes to 2 hours, optionally warming at -10 degrees C, hydrolyzing the siliylester by addition of methanol, concentrating the reaction solution to 1/10 of the original volume by removing tetrahydrofuran, precipitating the polymer in 1-molar hydrochloric acid, filtering out the polymer precipitate, collecting the polymer precipitate in water, dialyzing the aqueous washing mixture of the polymers through dialysis tube, evaporating the water of the dialysate, and finally drying the polymer over tetra-phosphorus decaoxide up to a constant weight under vacuum oil pump; and    (5) a polymer or membrane obtained from the process.    Hal = F, Cl, Br or I.