侧链接枝低聚对亚苯基亚乙烯基聚芴衍生物的合成及其电致发光性能

采用Wittig-Horner反应,将少量端基为磷脂的黄光发射客体低聚对亚苯基亚乙烯基链段(MOPV)接枝到含有醛基单体的蓝光发射主体材料聚芴的侧链上,合成了一种新型的接枝聚芴衍生物PF-g-MOPV.这种接枝聚合物具有很好的热稳定性,可溶于常用的有机溶剂.以接枝共聚物PF-g-MOPV为发光层的单层器件发射出黄绿光,色坐标为(0.30,0.57),最大发光亮度达到1550cm/m2,这说明蓝光聚芴主链向侧链MOPV进行了有效地能量转移.

SYNTHESIS AND ELECTROLUMINESCENT PROPERTIES OF A POLYFLUORENE GRAFTED OLIGO(PHENYLENEVINYLENE DERIVATIVE WITH TWO TRIPHENYLAMINE SIDE GROUP)

A polyfluorene derivative containing a monomer with bis-aldehyde functional group was synthesized according to Suzuki coupling reaction. Then,a small amount of oligo ( phenylenevinylene with two triphenylamine side group) ( MOPV) with bis-phosphonate functional groups was grafted to the polyfluorene derivative with bis-aldehyde functional groups by using Wittig-Horner method. The structures,thermal,optical and electrochemical properties of MOPV,pre-grafted polymer P1 and the grafted polymer PF-g-MOPV were characterized by 1H-NMR,GPC,DSC,TGA,UV-Vis,photoluminescence ( PL ) spectroscopy and cyclic voltammetry (CV),respectively. The grafted polymer exhibited better thermal properties than the pre-grafted polymer P1. The grafted polymer exihibited two PL emission bands ascribed to polyfluorene and MOPV segments,which indicated that Frster energy transfer from polyfluorene host to MOPV guest was efficient. This is the main mechanism in the PL process. To investigate the electroluminescent ( EL) characteristics of the grafted polymer,a single-layer PLEDs device with a configuration of indium tin oxide ( ITO ) /poly-(ethylenedioxythiophene):poly(styrenesulfonic acid) ( PEDOT∶ PSS) /polymer/Ca/Al was fabricated. The grafted polymer emitted yellowish-green light with the international commission on illumination ( CIE ) coordinates of (0. 30,0. 57 ) and the maximum brightness of 1550 cd /m2. The MOPV segments serve as effective sites for charge trapping,which can trap both electron and hole from the polyfluorene backbone. Charge trapping rather than Frster energy transfer is the main mechanism in the EL process.