A novel hyperbranched poly（phenylene oxide） （HPPO） with phenolic terminal groups was prepared from 4-bromo-4＇,4＂-dihydroxytriphenylmethane as AB2 monomer in dimethylsulfoxide （DMSO） via a modified Ullmann reac...A novel hyperbranched poly（phenylene oxide） （HPPO） with phenolic terminal groups was prepared from 4-bromo-4＇,4＂-dihydroxytriphenylmethane as AB2 monomer in dimethylsulfoxide （DMSO） via a modified Ullmann reaction. The molecular weight and polydispersity （PD） of the resulting polymers increased with increasing reaction time. In the presence of core molecules （bisphenol A and 1,3,5-trihydroxybenzene）, which have the similar molecular backbones to the reactive monomer, the molecular weight could be controlled by varying the core-to-monomer ratio. Incorporation of a very small amount of core molecules could lead to a higher molecular weight as compared with that without the addition of core molecules. However, when the core content reached certain extent, the molecular weight would decrease with the further increase in the core content. A new similar behavior of control over the PD was also obtained. The resulting polymers were characterized by ^1H-NMR, ^13C-NMR, FT-IR, and GPC.展开更多
Water\|soluble hyperbranched copoly(ester\|amine)s with various degree of branching (DB) were prepared \%via\% the "A\-2+B\-2+BB′\-2" approach. Due to the faster reaction between A and B functional groups, ...Water\|soluble hyperbranched copoly(ester\|amine)s with various degree of branching (DB) were prepared \%via\% the "A\-2+B\-2+BB′\-2" approach. Due to the faster reaction between A and B functional groups, the intermediate containing one A group and two B′ groups was generated\% in situ\%. Further self\|polyaddition of the AB′\-2 intermediate gave hyperbranched polymer. In this communication, A\-2 is ethylene diacrylate (EDA), B\-2 is piperazine (PZ), and BB′\-2 is 1\|(2\|aminoethyl)piperazine (AP). The combination of mass spectrum and \%in situ\% FTIR determined the reaction mechanism and propagating paths predicted. DB of the resulting branched poly(ester\|amine)s decreases with increasing the feed ratio of PZ to AP. In the same molecular weight, the inherent viscosity of the polymers presented here increases with decreasing DB. The simplicity of the reaction process, the controllability of the architecture, and the commercially availability of the raw materials would make this approach attractive in the large scale manufacture and application of hyperbranched polymer materials.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No. 50473042)the Beijing Natural Science Foundation (No. 2042017).
文摘A novel hyperbranched poly（phenylene oxide） （HPPO） with phenolic terminal groups was prepared from 4-bromo-4＇,4＂-dihydroxytriphenylmethane as AB2 monomer in dimethylsulfoxide （DMSO） via a modified Ullmann reaction. The molecular weight and polydispersity （PD） of the resulting polymers increased with increasing reaction time. In the presence of core molecules （bisphenol A and 1,3,5-trihydroxybenzene）, which have the similar molecular backbones to the reactive monomer, the molecular weight could be controlled by varying the core-to-monomer ratio. Incorporation of a very small amount of core molecules could lead to a higher molecular weight as compared with that without the addition of core molecules. However, when the core content reached certain extent, the molecular weight would decrease with the further increase in the core content. A new similar behavior of control over the PD was also obtained. The resulting polymers were characterized by ^1H-NMR, ^13C-NMR, FT-IR, and GPC.
文摘Water\|soluble hyperbranched copoly(ester\|amine)s with various degree of branching (DB) were prepared \%via\% the "A\-2+B\-2+BB′\-2" approach. Due to the faster reaction between A and B functional groups, the intermediate containing one A group and two B′ groups was generated\% in situ\%. Further self\|polyaddition of the AB′\-2 intermediate gave hyperbranched polymer. In this communication, A\-2 is ethylene diacrylate (EDA), B\-2 is piperazine (PZ), and BB′\-2 is 1\|(2\|aminoethyl)piperazine (AP). The combination of mass spectrum and \%in situ\% FTIR determined the reaction mechanism and propagating paths predicted. DB of the resulting branched poly(ester\|amine)s decreases with increasing the feed ratio of PZ to AP. In the same molecular weight, the inherent viscosity of the polymers presented here increases with decreasing DB. The simplicity of the reaction process, the controllability of the architecture, and the commercially availability of the raw materials would make this approach attractive in the large scale manufacture and application of hyperbranched polymer materials.
