TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Processes: Alternately, the side chain sulfonated polyaryletherketone is prepared by mixing methylene chloride as solvent and polyaryletherketone with dimethoxy naphthyl in ice bath, dropping solution containing methylene chloride and boron tribromide, maintaining at normal temperature for 8-12 hours, reflowing for 5-6 hours, filtering, washing for 3-5 times, drying in oven. The side chain sulfonated polyaryletherketone is also prepared by adding 1,5,4-fluorobenzene formoxyl-2,6-dimethoxy naphthalene, 4,4'-difluorobenzophenone and bisphenol monomer in three-holed bottle, mixing potassium carbonate (1.05-1.10 weight parts) as salt forming agent, N-methylpyrrolidone, dimethyl sulfoxide, dimethyl acetamide or sulfolane as solvent and toluene as dehydrant, dehydrating at 130-140 degrees C for 3-4 hours, heating at 170-190 degrees C for 4-8 hours, pouring reaction mixture into water, crushing, boiling, filtering using distilled water for 5-6 times, and drying in oven. Similarly, side chain sulfonated polyaryletherketone is prepared by mixing 300-350 ml of chloroform as solvent, 2,6-dimethoxy naphthalene and 4-fluorobenzoyl chloride, adding anhydrous aluminum trichloride, anhydrous ferric oxide or anhydrous zinc chloride, reacting at 0-4 degrees C for 16-48 hours, pouring resulting dark purple solution to 0.5-1 mol/L of solution of dilute hydrochloric acid for 2-3 hours, washing using water for 3-6 times, collecting oily liquid, adding hexamethylene, and recrystallizing resulting mixture using mixed solvent of N,N-dimethyl formamide and water in volume ratio of 10-20:1. The side chain sulfonated polyaryletherketone (2-3 g) is dissolved in 10-20 ml of dimethyl acetamide, poured into watch glass having diameter of 10-20 cm, baked at 60-80 degrees C for 24-36 hours in oven, to obtain film. Preferred Composition: The mol ratio of boron tribromide and dimethoxy naphthyl is 2-2.5:1. The concentration of solution is 10-20 mass%. The content of 1,5,4-fluorobenzene formoxyl-2,6-dimethoxy naphthalene is x weight parts. The content of 4,4'-difluorobenzophenone is (1-x) weight parts. The mol ratio of 2,6-dimethoxy naphthalene, 4-fluorobenzoyl chloride and anhydrous aluminum trichloride is 1:2.5-3:2.5-3.5. The mol ratio of 2,6-dimethoxy naphthalene, 4-fluorobenzoyl chloride, anhydrous ferric oxide or anhydrous zinc chloride is 1:2.5:0.1-0.15. The content of 2,6-dimethoxy naphthalene is 0.1 mol. The sultone is 1,3 propyl sultone or 1,4-butyl sultone.