以具有高荧光量子效率的二(4-羟基苯乙烯基)苯(PV)为A2发光单体,以四官能度的对甲基苯磺酸季戊四醇酯为B4支化单体,采用A2+B4的路线,合成了一类新型的具有三维结构的部分共轭型超支化电致发光聚合物;为了改善聚合物中载流子的平衡注入能力,又分别在分子的骨架和外围引入具有良好电子传输功能的嗯二唑(OXD)基团;利用核磁共振、DSC、紫外-可见分光光度计、荧光光谱仪等分析测试手段对单体及聚合物进行了结构与性能表征。结果表明:具有超支化结构的聚合物热稳定性明显改善;嗯二唑基团的引入有利于提高聚合物的玻璃化温度;将嗯二唑基团引入到分子中后,其紫外吸收光谱和荧光光谱均出现蓝移现象,降低了电子注入势垒。
Using 4, 4'-(p-phenylenedi-1, 2-ethenediyl)-diphenol (PV) as an A2 emitting monomer, and pentaerythritol p-toluenesulfonate as a B4 branching monomer, a series of partially conjugated electroluminescent hyperbranched polymers HPD and HP111, with genuine three-dimensional architecture, were synthesized by adopting an A2 + B4 polymerization route. To balance the electron-and hole-injection and improve the fluorescence quantum efficiency, moieties bearing electron-deficient oxadiazole (OXD) were introduced either in the exterior or in the interior of the polymers. The influence of varying the dosage of monomers and reaction temperature on the properties of the polymers was studied. The results demonstrated that introduction of OXD is helpful in terms of increasing the glass transition temperature (Tg) of the polymers. The photophysical properties of polymers bearing OXD moieties were modified to different extents.