- Synthesis and sulfonation of poly(aryl ethers) containing triphenyl methane and tetraphenyl methane moieties from isocynate-masked bisphenols
-
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.
- Wang,Meng,Wang,Shang,Li,Hay
-
p. 3151 - 3158
(2007/10/03)
-
- Mechanically linked polyrotaxanes: A stepwise approach
-
A new synthetic approach for the preparation of mechanically linked polyrotaxanes was developed. Two variations of rotaxane monomers were synthesized, based on diphenylmethane and tetraphenylmethane blocking groups. Both rotaxanes bear a protected phenol
- Werts, Michel P.L.,Van Den Boogaard, Maarten,Tsivgoulis, Gerasimos M.,Hadziioannou, George
-
p. 7004 - 7013
(2007/10/03)
-
- Polymer electrolyte and process for producing the same
-
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.
- -
-
-
- Processes for producing aromatic polycarbonate oligomer and aromatic polycarbonate
-
A process for producing continuously an aromatic polycarbonate oligomer by reacting an aromatic dihydroxy compound and an alkali metal base or an alkaline earth metal base with a carbonyl halide compound comprises: (1) feeding continuously to a tank reactor an aromatic dihydroxy compound, water, a molecular weight controlling agent, a polymerization catalyst, a carbonyl halide compound, and an organic solvent, and an alkali metal base or an alkaline earth metal base in an amount of 1.15-1.6 equivalents based on the aromatic dihydroxy compound, (2) carrying out the reaction with a residence time as defined by the following formula, where X is an amount of the polymerization catalyst in terms of mole % based on the amount of mole of the aromatic dihydroxy compound fed per unit time, and Y is a residence time (min.), and (3) continuously withdrawing the reaction mixture from the tank reactor to obtain an aromatic polycarbonate oligomer having a number average molecular weight of 1,000-10,000. An aromatic polycarbonate is produced by polycondensation of the aromatic polycarbonate oligomer.
- -
-
-
- Method for preparing aromatic bischloroformate compositions
-
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.
- -
-
-
- Bischoloroformate preparation method with phosgene removal and monochloroformate conversion
-
Aqueous bischloroformates are prepared by the reaction of a dihydroxyaromatic compound (e.g., bisphenol A) with phosgene in a substantially inert organic liquid (e.g., methylene chloride) and in the presence of an aqueous alkali metal or alkaline earth metal base, at a pH below about 8. After all solid dihydroxyaromatic compound has been consumed, the pH is raised to a higher value in the range of about 7-12, preferably 9-11, and maintained in said range until a major proportion of the unreacted phosgene has been hydrolyzed. At the same time, any monochloroformate in the product may be converted to bischloroformate.
- -
-
-
- Cyclic monocarbonate bishaloformates
-
Cyclic monocarbonate bischloroformates are prepared by the reaction of a carbonyl halide such as phosgene with a bridged substituted resorcinol or hydroquinone such as bis(2,4-dihydroxy-3-methylphenyl)methane or bis(2,5-dihydroxy-3,4,6-trimethylphenyl)methane in the presence of aqueous alkali metal hydroxide. The cyclic monocarbonate bischloroformates may be used for the preparation of linear or cyclic polycarbonates containing cyclic carbonate structural units, which may in turn be converted to crosslinked polycarbonates.
- -
-
-
- Polyetherimide bisphenol compositions
-
Polyetherimide bisphenols and bischloroformates are prepared by the reaction of dianhydrides or certain bisimides with aminophenols or mixtures thereof with diamines. They are useful as intermediates for the preparation of cyclic heterocarbonates, which may in turn be converted to linear copolycarbonates. The bisphenols can also be converted to salts which react with cyclic polycarbonate oligomers to form block copolyetherimidecarbonates.
- -
-
-
