一种含三苯胺链段的PPV类交替共聚物的合成、表征及性能

合成了三苯胺二醛和1-甲氧基-4-辛氧基-2,5-二甲苯双(三苯基氯化)两种单体,通过Wittig反应制得了共轭聚合物,对共轭聚合物进行了表征和性能测试.这类共轭聚合物的氯仿溶液和膜在紫外光激发下能发出强的蓝绿光,与小分子三苯胺衍生物(TPD)相比,具有相对较高的热稳定性和良好的成膜性.电化学分析表明聚合物具有很好的空穴传输能力.同时对共轭聚合物的光致发光和电致发光性能进行了研究,结果表明,此聚合物与同类聚对亚苯基亚乙烯基(PPV)型聚合物相比具有较低的驱动电压和较高的发光亮度,是一种潜在的有机高分子电致发光材料.

SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF A PPV CONJUGATED POLYMER CONTAINING TRIPHENYLAMINE SEGMENT

Diformaltriphenylamine and 1-methoxy-4-octoxyl-2,5-xylenebis(triphenyl phosphonium chloride) were synthesized,and their copolymer(TPA-MOPPV) was obtained through a Wittig polycondensation.The structures of the monomer and copolymer were characterized by FT-IR,UV-Vis,()~1H-NMR and fluorescence spectrum.The optical properties and thermal behavior were discussed in detail.A strong blue-greenish light,with 503 nm maximum wavelength,was observed for the copolymer in 0.01 g/L CHCl_3 solution.Furthermore,concentrations on photoluminescence property of the polymer was investigated.The results showed that the maximum excitation wavelength was approximately 440 nm when the concentration of the copolymer was under 0.01 g/L,but the maximum excitation wavelength exceeded 492 nm after the concentration was above 0.01 g/L.The copolymer is readily soluble in common organic solvents at room temperature,so it could be easy to prepare electroluminescent device by spin-coat technology.The electrochemical studies suggested the hole injection and hole transport properties could be improved because of introducing the triphenylamine units.Its electroluminescence properties were investigated,a polymer light emitting diode with the TPA_MOPPV as the active layer (ITO/PEDOT:PSS/TPA-MOPPV/Ba/Al) showed greenish yellow emission with luminance over 369 cd/m~2 at 6 V and the low turn-on voltage(3.2 V),the maximum external quantum efficiency was 0.14%.DSC analysis showed that T_g of the polymer was(23 K) higher than that of triphenylamine derivatives TPD,and the results of TG indicated that the decomposition temperature of TPA-MOPPV was 208℃ and the polymer did not displays apparent weight loss until 360℃.In a word,the polymer exhibits strong fluorescence,relatively high thermal stability,good film-forming capability,high luminance,good hole-transporting property,being a good candidate of electroluminescent material.