含空间位阻基团的超支化聚芴的合成、表征及稳定性研究  

SYNTHESIS,CHARACTERIZATION AND THERMAL STABILITY OF HYPERBRANCHED POLYFLUORENES CONTAINING STERICALLY HINDERED GROUPS

作　　者：覃春杨[1] 刘烽[1] 彭波[1] 黄维[2] 韦玮[1] 

机构地区：[1]复旦大学信息科学与工程学院光科学与工程系先进光子学材料与器件国家重点实验室,上海200433 [2]南京邮电大学信息材料与纳米技术研究院,南京210003

出　　处：《高分子学报》2008年第6期537-543,共7页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号60578039、90406021)资助项目

摘　　要：以1,3,5-间三溴苯和三(4-溴苯基)胺为支化核,引入9,10-二溴蒽和2,7-二溴-螺(芴-9,9-氧杂蒽)通过Suzuki反应与芴分别共聚,得到4种不同结构的超支化聚芴蓝光材料,对其结构及光物理性质进行了表征,根据退火前后荧光光谱的变化对其光谱热稳定性进行了研究.实验结果表明,引入超支化结构和高位阻基团,聚芴的荧光发射光谱热稳定性显著提高,绿光区发射现象几乎完全被抑制.Four kinds of sterically hindered groups-based hyperbranched polyfluorene copolymers containing different branching units such as benzene or triphenylamine were designed and synthesized.All the monomers such as 2,7-dibromo-9,9-dioctylfluorene,2,7-dibromospiro（fluorene-9,9′-xanthene）, 9,9-dioctylfluorene-2,7-bis（4,4,5,5-tetramethyl-1,3,2-dioxaborolane） and 9,9-dioctylfluorene-2-boronic acid were prepared according to the literature procedures.Suzuki polycondensation （SPC） with the branching units and linear units was conducted in biphasic system （toluene/aqueous Na2CO3） with Pd（PPh3）4 as a catalyst precursor.The reaction mixture containing monomers was kept stirring at 72℃ under nitrogen for 60 h at the polymerization stage.Then,the end-capped group was added to the reaction mixture together with additional Pd（PPh3）4 in order to reduce the heavy atom effect which quenched fluorescence.The reaction was continued for further 12 h.After cooling to room temperature,some amount of thiourea was added,and then the mixture was vigorously stirred for another 3 h.The mixture was filtrated to remove the catalyst residues and extracted with toluene.After removal most of the solvent,the crude polymer in certain amount of toluene was added dropwise to methanol and the formed precipitate was recovered by filtration.The solid was washed with methanol,water and again with methanol,then followed by Soxhlet extraction with acetone for 48 h to remove oligomer.The yellow powder was collected and dried under vacuum.All the resulting hyperbranched copolymers are soluble in common organic solvents,such as tetrahydrofuran,chloroform and toluene.The structures of the hyperbranched polymers were fully characterized by NMR,GPC,elementary analysis and thermogravimetric analysis.The degrees of branching of the polymers were calculated through the integration of the characteristic signals of the branching units and linear units from the high-resolution NMR spectroscopy.The GPC experimental results showed that the num

关 键 词：超支化 聚芴 空间位阻 聚集态 绿光发射 

分 类 号：O631[理学—高分子化学]