主链含有非共轭结构的聚芴类蓝光聚合物的合成与性能研究

Synthesis and Characterization of Blue-light Emitting Polyfluorenes Containing Non-conjugated Structure in Backbone

通过Suzuki偶合反应合成出了主链中含有非共轭烷氧基组分(-O-CH2-CH2-CH2-CH2-O-)的聚芴类衍生物聚-2,7-(9,9-二辛基芴)-co-4,4'-丁氧基二苯(PFP)和聚-2,7-(9,9-二辛基芴)-co-4,4'-丁氧基二苯-co-N-苯基-4,4'-二苯胺(PFTP11)并通过相同的条件合成出主链由芴和三苯胺交替相连的聚合物聚-2,7-(9,9-二辛基芴)-co-N-苯基-4,4'-二苯胺(PFTPA)作为参比材料.通过1HNMR和FT-IR分析对这些聚合物的化学结构进行了表征.这三种聚合物在常用的有机溶剂中具有很好的溶解性,可通过溶液加工的方式制备聚合物薄膜.这些聚合物均具有较高的热分解温度(>400℃),聚合物PFP具有较高的玻璃化转变温度(～130℃)而PFTP11和PFTPA则未出现明显的玻璃化转变过程.通过对聚合物的吸收特性进行测试得知它们具有较大的光学带宽(2.89～3.29eV).所有聚合物在固体薄膜状态下均发射出蓝色荧光,PFP,PFTP11和PFTPA的最大PL发射分别位于425,437和440nm.通过对其电化学性能进行测试可知由于三苯胺基团的引入聚合物的HOMO能级明显提高,这意味着聚合物的空穴传输能力得到了有效的改善.

Polyfluorene derivatives with non-conjugated alkoxy segment （-O-CH2-CH2-CH2-CH2-O-） in backbone, poly（9,9-dioctyl-2,7-fluorene-co-4,4＇-butoxydiphenyl） （PFP） and poly（9,9-dioctyl-2,7-fluorene- co-4,4＇-butoxydiphenyl-co-N-phenyl-4,4＇-diphenylamine） （PFTPll）, were synthesized by Suzuki coupling reaction and the control polymer with alternating fluorene and triphenylamine groups as main chain, poly（9,9-dioctyl-2,7-fluorene-co-N-phenyl-4,4＇-diphenylamine） （PFTPA）, was prepared under the same polymerization condition. The chemical structures of above-mentioned polymers were verified by ^1H NMR and FT-IR analyses. These polymers showed good solubility in common organic solvents, and the solid films of them can be facilely obtained by solution processing. All of these polymers possess high thermal stability, with thermal decomposition temperature above 400 ℃. PFP possesses relatively high Tg temperature （at around 130 ℃）, but for PFTP11 and PFTPA there was no obvious glass transition process observed. UV-Vis investigation of these polymers indicates the wide bandgaps of them （2.89-3.29 eV）. The films of PFP, PFTP11 and PFTPA emitted blue light, with the maximum PL emission at 425,437 and 440 nm, respectively. The investigation of the electrochemical properties of these polymers reveals that the HOMO levels of PFTP11 and PFTPA were significantly higher than that of PFP due to the introduction of triphenylamine group, suggesting the improvement of hole-transport capability of them.