Hyperbranched aryl polycarbonates derived from A2B monomers versus AB2 monomers
Hyperbranched aryl polycarbonates derived from A2B monomers versus AB2 monomers
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DOI：
10.1002/pola.10167
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发表时间：
2002-04-01
影响因子：
--
通讯作者：
Wooley, KL
中科院分区：
文献类型：
--
作者：
Bolton, DH;Wooley, KL
Hyperbranched aryl polycarbonates were prepared via the polymerizations of A(2)B and AB(2) monomers, which involved the condensation of chloroformate (A) functionalities with tert-butyldimethylsilyl-protected phenols (B), facilitated by reactions with silver fluoride. The polymerization of the A(2)B monomer gave hyperbranched polycarbonates bearing fluoroformate chain ends, which were hydrolyzed to phenolic chain-end moieties and further elaborated to tert-butyldimethylsilyl ether groups. The polymerization of the AB2 monomer gave tert-butyldimethylsilyl ether-terminated hyperbranched polycarbonates. The polymerizations were conducted at 23-70 degreesC in 20% acetonitrile/tetrahydrofuran in the presence of a stoichiometric excess of silver fluoride for 20-40 h to afford hyperbranched polycarbonates with weight-average molecular weights exceeding 100,000 Da and polydispersity indices of typically 2-3. The degrees of branching were determined by a reductive degradation procedure followed by high-performance liquid chromatography. Alternatively, the degrees of branching were measurable by solution-state H-1 NMR analyses and agreed with the statistical 50% branching expected for the polymerization of AB and AB2 monomers not experiencing constructive or destructive electronic effects on the reactivity of the multiple functional groups. (C) 2002 Wiley Periodicals, Inc.
