- Polymer electrolyte and process for producing the same
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A polymer electrolyte having, in a main chain, a structural unit represented by the following formula (1):-[Ar1-(SO2-N-(X+)-SO2-Ar2)m-SO2-N-(X+)-SO2-Ar1-O]- wherein Ar1 and Ar2 independently represent a divalent aromatic groups, m represents an integer of 0 to 3, and X+ represents an ion selected from hydrogen ion, an alkali metal ion and ammonium ion, which is excellent in proton conductivity, thermal resistance and strength. The polymer electrolyte is soluble in solvents and has excellent film forming property and recycling efficiency.
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- Sulfonation and sulfation on reaction of 1,4-dihydroxybenzene and its methyl ethers in concentrated sulfuric acid
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The homogeneous reactions of 1,4-dihydroxybenzene (1), its monomethyl (2) and dimethyl ether (3) and 2-3-sulfonic acid in 68-105percent H2SO4 at 25 deg C have been studied and isomer distributions and rate coefficients for the various subsequent sulfonations, as well as the equilibrium data for the sulfation (-OH -OSO3H), are reported.For 2, the ratio of 2- to 3-sulfonation decreases upon increasing the sulfuric acid concentration from 68-98.5percent H2SO4, due to a gradual change-over in the effective sulfonating entity from H3SO4(1+) to H2S2O7.For 1-2-sulfonic acid (1-2-S), 2-2-S and 2-3-S, the ratios of 5- to 6-sulfonation are all ca. 25:75, whereas 3-2-S only yields the 5-sulfonic acid.Demethylation of the sulfonic acids of 2 and 3 in = 98.5percent H2SO4 is of minor importance, but plays a major role in 105,0 percent H2SO4, the eventual products being the bis(hydrogen sulfate)s 10 and 15, the tricyclic bis(sulfate sulfonate anhydride) 11 and the bicyclic hydrogen sulfate 16.Mechanisms for the sulfodemethylation and for the cyclization of the 2-sulfophenyl hydrogen sulfate moiety to the 1,3,2,4-benzodioxadithiin 2,2,4,4-tetraoxide system are proposed.
- Cerfontain, Hans,Koeberg-Telder, Ankie
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p. 583 - 591
(2007/10/02)
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