TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polyarylether copolymer has the structure of formula (-((T-A-T-B1)x-)-((T-A-T-D)y)-) (A) with a random or block arrangement in the polymer microstructure. The polyarylether copolymer is a random copolymer, and/or block copolymer, preferably sulfonated polyaryletherketone, or a sulfonated polyarylethersulfone bonded to a polyarylethersulfone, or a sulfonated polyaryletherketone bonded to a polyarylethersulfone, or a polyaryletherketone chain. The polyarylether backbone is optionally sulfonated. The polyarylether copolymer has: a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 2-4.5, where Mn is 25000-200000; an ion exchange capacity of 0.1-4 milliequivalents per gram of dry polyarylether copolymer; a proton conductivity of 0.01-1 siemens per centimeter at 80 degrees Celsius and a relative humidity of 100 percent; and a water uptake of 30-200% at 100 degrees C. The polyarylether backbone comprises a polyethersulfone, a polyaryletherketone or their copolymers or derivatives. The sulfonated oligomeric group comprises a sulfonated polyaryletherketone, or a sulfonated polyarylethersulfone, or their copolymers or derivatives. The length of the sulfonated oligomeric group is determined by the repeating unit of its monomer, where the repeating units of the monomer are 1-25. (I) has the structure of formula (II) or (III).T, T1a = O or S;A = phenyl or pyridine (both optionally substituted), biphenyl group of formula (a), 1-20C aliphatic diradical, 3-40C aromatic diradical, 4-20C cycloaliphatic diradical, 3-40C heterocycle diradical;Y1, Y1a = direct bond, O, S, (CH2)r, (CF2)r, C(CH3)2, and/or C(CF3)2;R1-R4 = 1-10C alkyl, 3-12C cycloalkyl, 6-14C aryl, allyl, alkenyl, alkoxy, halo, CN, NO2, or perfluorinated alkyl such as CF3;r = 1-5;a = 0-4;B1 = benzenesulfonic acid groups of formula (a1), (a2) or (a3), such as benzonitrile sulfonyl group of formula (a4);Z, Z1, Z2, Z3 = direct bond, CO, SO2, 1-20C aliphatic diradical, 3-40C aromatic diradical, or 4-20C cycloaliphatic diradical;R2 = 1-10C alkyl, 3-12C cycloalkyl, 6-14C aryl, allyl, alkenyl, alkoxy, halo, nitro, perfluorinated alkyl such as CF3, or CN;m = 0-4;b = 0-3;X = OM;M = H, metal cation, nonmetallic inorganic cation, and/or organic cation;X = biphenyl group of formula (a5);Z3 = bond, CO, SO2, 1-20C aliphatic diradical, 3-40C aromatic diradical, or 4-20C cycloaliphatic diradical;R5 = 1-10C alkyl, 3-10C cycloalkyl, 6-14C aryl, allyl, alkenyl, alkoxy, halo, nitro, perfluorinated alkyl, such as CF3, or CN;e = 0-3;T = O and/or S;p, r = 1-5;E = amine-containing aromatic diradical, aliphatic diradical or cycloaliphatic diradical, where the nitrogen is bound as a sulfonamide to the polymer backbone, preferably cyclohexylamine moiety, pyrrolidine moiety or phenylamine moiety (all optionally substituted);D = substituted phenyl groups of formula (a6), (a7) or (a8);R4 = 1-10C alkyl, 3-10C cycloalkyl, 6-14C aryl, allyl, alkenyl, alkoxy, halo, nitro, perfluorinated alkyl, such as CF3, or CN;d, n = 0-4;Z1a = direct bond, CO, SO2, 1-20C aliphatic diradical, 3-40C aromatic diradical, or 4-20C cycloaliphatic diradical; andx, y = 0-500.In formula (II) and (III):Z1a, Z1, Z2 = bond, CO, SO2, 1-20C aliphatic diradical, 3-40C aromatic diradical, or 4-20C cycloaliphatic diradical;X = OM or (a5); andM = H, a metal cation, a non-metallic inorganic cation, and/or an organic cation.Preferred Method: The method further comprises: forming the polyarylether copolymer, and controlling ratio of Mw to Mn of 2-4.5 and controlling Mn of 25000-200000. EXAMPLE - No suitable example given.