1844-01-5Relevant articles and documents
Synthesis and sulfonation of poly(aryl ethers) containing triphenyl methane and tetraphenyl methane moieties from isocynate-masked bisphenols
Wang,Meng,Wang,Shang,Li,Hay
, p. 3151 - 3158 (2007/10/03)
Wholly aromatic poly(aryl ethers) containing triphenylmethane and tetraphenylmethane moieties were successfully synthesized by aromatic nucleophilic substituting polycondensation from masked bisphenols and decafluorobiphenyl followed by sulfonation with chlorosulfonic acid. The sulfonation took place only at the para positions on the pendant phenyl rings due to the novel biphenol structures designed. For the synthesized polymers, the sulfonation content can be easily controlled and the water-takeup can be conveniently tailored by changing the amount of sulfonation agent. These sulfonated polymers are soluble in polar organic solvents, such as NMP, dimethylacetamide, dimethyl sulfoxide, dimethylformamide, and ethylene glycol monomethyl ether and can be readily cast into tough and smooth films from solutions. The films exhibited very high water absorption ability and superior mechanical strength. These polymers also showed high glass transition temperatures ranging from 176 to 203°C compared with Nafion. The sulfonated polymers can be potentially used as the proton-exchange membranes for fuel cells.
Polymer electrolyte and process for producing the same
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, (2008/06/13)
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.
Method for preparing aromatic bischloroformate compositions
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, (2008/06/13)
Bischloroformate oligomer compositions are prepared by passing phosgene into a heterogeneous aqueous-organic mixture containing at least one dihydroxyaromatic compound, with simultaneous introduction of a base at a rate to maintain a specific pH range and to produce a specific volume ratio of aqueous to organic phase. By this method, it is possible to employ a minimum amount of phosgene. The reaction may be conducted batchwise or continuously. The bischloroformate composition may be employed for the preparation of cyclic polycarbonate oligomers or linear polycarbonate, and linear polycarbonate formation may be integrated with bischloroformate composition formation in a batch or continuous process.