摘要:
Polycarbonate having increased end-cap levels is made by adding an end-capping agent to the polycarbonate, preferably after the polycarbonate has reached a number-average molecular weight of about 2,000 to 15,000 Dalton. The end-capping agent has the formula: wherein R1 is a phenyl, phenoxy, benzyl, or benzyloxy and R2 is selected from the group consisting of C1-C30 alkyl, C1-C30 alkoxy, C6-C30 aryl, C6-C30 aryloxy, C7-C30 aralkyl, and C7-C30 aralkyloxy.
摘要:
Reactive monomers containing the trifluorovinyloxy group may be copolymerized to form polymers useful as membranes, especially polymer electrolyte membranes for fuel cells. The monomers have the formula ((CF2CFO(R1)p)nArX2 wherein Ar is a trivalent, tetravalent or pentavalent, substituted or unsubstituted, aromatic or heteroaromatic, monocyclic or polycyclic group having from 5 to 50 carbon atoms; X is OH, SH, NR2aR2b, F or Br; p is 0 or 1; n is 1, 2 or 3; R1 is substituted or unsubstituted phenyl and R2a and R2b are independently H, C1-C8 alkyl or C1-C8 perfluoroalkyl.
摘要翻译:含有三氟乙烯基氧基的反应性单体可以共聚以形成可用作膜的聚合物,特别是用于燃料电池的聚合物电解质膜。 这些单体具有式((CF 2)CFO(R 1))N 2 Ar 2 其中Ar是具有5至50个碳原子的三价,四价或五价,取代或未取代的芳族或杂芳族单环或多环基团; X是OH,SH,NR 2a R F或Br; p为0或1; n为1,2或3; R 1为取代或未取代的苯基且R 2a为H 2 O >和R 2b独立地为H,C 1 -C 8烷基或C 1 -C 3 - 8 u>全氟烷基。
摘要:
The above deficiencies in the art are alleviated by, in an embodiment, a method of preparing a carboxylic acid end-capped oligomer comprising melt reacting a dicarboxylic acid, a dihydroxy compound, a hydroxy end-capped soft block compound, a diaryl carbonate, and a catalyst, wherein the molar ratio of dihydroxy end-capped soft block compound to dihydroxy compound is 1:4 to 1:40, the molar ratio of dicarboxylic acid to the combined molar amounts of dihydroxy compound and hydroxy end-capped soft block compound is 1.01:1 to 2:1, and the molar ratio of diaryl carbonate to the combined molar amounts of dihydroxy compound and hydroxy end-capped soft block compound is 1.5:1 to 3:1. A carboxylic acid end-capped oligomer prepared by the above method is also disclosed. A thermosetting composition comprising the carboxylic acid end-capped oligomer, and an article comprising the thermosetting composition, are also disclosed.
摘要:
Sulfonated block copolymers that may be used as membranes for fuel cells include sulfonated polyaryletherketone blocks and lightly sulfonated polyethersulfone blocks. The sulfonated polyaryletherketone blocks include structural units of formula and the lightly sulfonated polyethersulfone blocks include structural units of formula wherein R1, R2, R3, R4, R5 and R6 are independently C1-C10 alkyl, C3-C12 cycloalkyl, C6-C14 aryl, allyl, alkenyl, alkoxy, halo, or cyano; Z, Z1 and Z2 are independently a direct bond or O, S, (CH2)r, (CF2)r, C(CH3)2, C(CF3)2, or a combination thereof; M is H, a metal cation, a non-metallic inorganic cation, an organic cation or a mixture thereof; a and e are independently 0 or an integer from 1 to 3; b, c, d, and f are independently 0 or an integer from 1 to 4; m, n and p are independently 0 or 1; and r is an integer from 1 to 5.
摘要:
Copolyetherimides compositions having high glass transition temperatures and outstanding ductility are presented. The copolyetherimides having Mw of at least 40,000 comprising isomeric bis(phthalimide) structural units within a relatively narrow range of isomer proportions exhibited Tgs of at least 240° C. and outstanding Notched Izod values. The copolyetherimides comprise oxydianiline residues and structural units of the formulas (I) and (II) (III). The copolyetherimides are characterized by a mole percentage of structural units derived from 4,4′-biphenol in a range from about 55% to about 85% of all bisphenol-derived structural units present in the copolyetherimide composition; a mole percentage of structural units derived from bisphenol A in a range from about 45% to about 15% of all bisphenol-derived structural units present in the copolyetherimide composition; and a total mole percentage of structural units derived from bisphenol A or 4,4′-biphenol of at least 95% of all bisphenol-derived structural units present in the copolyetherimide composition.
摘要:
The present invention provides carboxy-terminated oligomeric polyester compositions useful in the preparation of “weatherable” polymeric materials, for example weatherable copolyestercarbonates. In one aspect the present invention provides an oligomeric polyester composition comprising structural units derived from at least one diacid, at least one diaryl carbonate and at least one diol. The structural units derived from the diacid are present in a molar excess of from about 10% to about 40% based on a ratio of moles of diacid-derived structural units to moles of diol-derived structural units present in the oligomeric polyester composition. The oligomeric polyester composition is further characterized by the presence of atleast some phenoxy end groups.
摘要:
Nanocomposite compositions comprising organoclays and telechelic polyesters that contain sulfonate end groups were prepared that resulted in improved physical and mechanical properties.
摘要:
Novel polyethersulfone compositions have been discovered which incorporate structural subunits derived from sulfonated bis(halophenyl)sulfones, dihydroxy terphenyls, and/or bis(hydroxyphenyl)pyridines. The sulfonated polyethersulfones show promise as materials for use in polymer electrolyte membranes (PEMs) in fuel cells owing to their high proton conductivities (0.02-0.07 S/cm at 20° C. and 100 percent humidity). In addition, a novel unsulfonated thermoplastic polyethersulfone comprising structural subunits derived from a non-sulfonated bis(halophenyl)sulfone bis4-fluorophenyl)sulfone and 4,4′-dihydroxyphenyl-2,6-pyridine (CAS No. 171820-16-9) is disclosed.
摘要:
Efficient and cost-effective methods for producing hydroxyl-terminated arylates are disclosed. These arylates are useful in forming block polyarylate-polycarbonate copolymers.