TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The alkaline condition includes using potassium carbonate or sodium carbonate in an organic solvent system.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of the aromatic diamine monomer involves under the protection of nitrogen, adding 2,2'-bis(3-bromo-4-fluorophenyl) sulfone and 3,5-di(trifluoromethyl)phenyl boric acid in mol ratio of 1:2.0 to 2.3 to a three-mouth flask, then adding tetrakis(triphenylphosphine) palladium, sodium carbonate, toluene and water, stirring at room temperature uniformly, heating to reflux state, reacting for 8 to 16 hours, drying toluene, filtering the crude product, drying and re-crystallizing to obtain the intermediate 2,2'-bis(3-(3,5-di-(trifluoromethyl)phenyl)-4-phenyl sulfone, under the protection of nitrogen, adding the intermediate 2,2'-bis(3-(3,5-di(trifluoromethyl)phenyl)-4-phenyl sulfone and aminophenol in mol ratio of 1:2.0 to 2.2, under the alkaline condition reacting at 110-140 degrees C for 8 to 12 hours, finishing the reaction, pouring reactant into ice water bath, separating out large amount of solid powder, filtering crude product, drying, further separating by using silica gel column chromatography and purifying to form diamine monomers (I) and (II). The silica gel column chromatography separation and purification is conducted using solvent containing mixed solvent of chloroform and petroleum ether, where the volume ratio of the mixed solution of chloroform and petroleum ether is 3 to 5:1. Preferred Components: The aminophenol is selected from 4-aminophenol or 3-aminophenol. The amount of tetrakis (triphenyl phosphine) palladium is 0.2-0.4 times the amount of 2,2'-bis(3-bromo-4-fluorophenyl)sulfone. The amount of sodium carbonate is 6 times the amount of 2,2'-bis(3-bromo-4-fluorophenyl) sulfone. The amount of toluene is 1.1-1.3 times that of acetylacetic ether amount. The organic solvent is selected from N,N-dimethyl formamide, N,N-dimethyl acetamide or N-methyl pyrrolidone.