Puyao Guo, Gi-Eun Kim*, Chang-Jae Yu*, Jae-Hoon Kim*,#, Kwang-Un Jeong**, and E-Joon Choi#,†
Department of Polymer Science and Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 39177, Korea
*Department of Electronic Engineering, Hanyang University, Seoul 04763, Korea
**Department of Polymer-Nano Science and Engineering, Jeonbuk National University, Jeonju 54896, Korea
금오공과대학교 고분자공학과, *한양대학교 전자공학과, **전북대학교 고분자나노공학과
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A series of phosphorescent mesogenic copolymers with various feed ratios of iridium-coordinating monomer as a side group have been prepared. Structure and composition of copolymers were confirmed by Fourier-transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. Molecular weight of copolymers was determined to be in the range of 7 to 73 kDa by GPC measurement. UV-Vis absorption and photo- and electroluminescence properties of copolymers were investigated. As a result, copolymer IrCP-1 containing 1 mol% iridium-coordinating comonomer showed the highest luminance and current density. Copolymer IrCP-3 with 5 mol% iridium-coordinating comonomer exhibited a satisfactory dichroic ratio of 1.47.
인광성 메소제닉 공중합체의 이색성을 평가하기 위하여 이리듐이 배위된 치환체를 곁사슬에 갖는 폴리플루오렌 공중합체를 합성하였다. 이때 벤조치아디아졸, 디옥틸플루오렌 및 이리듐착물-치환 플루오렌의 조성비를 1, 2, 5, 8, 11, 25 및 37.5 mol%로 변화시켰다. 합성한 공중합체의 구조 및 조성을 Fourier-transform infrared (FTIR) 및 proton nuclear magnetic resonance (1H NMR) 분광분석법으로 조사하였다. 또한 공중합체의 UV-Vis 흡수, 광발광 및 전기발광 특성을 조사하였다. 공중합체의 분자량은 GPC 측정에 의해 7 내지 73 kDa 범위로 결정되었다. 결과적으로 배향된 이리듐착물-치환 플루오렌 구조를 1 mol% 및 5 mol%로 갖는 공중합체를 각각 적용한 전기발광 소자가 각각 가장 높은 휘도 및 가장 뚜렷한 이색성비(1.47)를 나타내었다.
Keywords: liquid crystalline polymer, polarized light, fluorescence, phosphorescent, electroluminescence.
2023; 47(4): 519-527
Published online Jul 25, 2023
Department of Polymer Science and Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 39177, Korea