Synthesis of poly[2-(2-ethylhexyloxy)-5-methoxy-1,4-phenylene vinylene]-block-Poly (2,3-diphenyl-5-octyl-p-phenylene vinylene)(MEH-PPV-block-DPO-PPV) and investigate it's luminescent properties

本研究是利用Wittig-Horner方法製備出含有MEH-PPV與DPO-PPV鏈段的團狀共聚物MEH-PPV-block-DPO-PPV，當兩種高分子鏈段均達飽和共軛鏈長時，可使此diblock copolymer有比純的MEH-PPV及DPO-PPV更好的發光效率；我們另外也用Witiig-Horner合出純的MEH-PPV、及DPO-PPV高分子，並利用NMR氫譜鑑定其結構，DSC、TGA判斷其熱性質。 我們利用控制反應機制與時間成功合成了diblock copolymer 及另外兩種高分子。三種高分子在溶液狀況下，DPO-PPV為藍綠光，MEH-PPV為橘紅光，而MEH-PPV-block-DPO-PPV為黃光，三種的螢光強度均很高。Witiig-Horner反應為醛基與磷基的縮合反應，所以聚合物分子量無法聚得很大。當我們製備為有機發光二極體時，MEH-PPV的起始電壓為3.9V，最大亮度在12.2V時有102 cd/m2時。MEH-PPV-block-DPO-PPV在三種高分子中，擁有最好的效率，其起始電壓3.1V，且在9V時可得最大亮度525 cd/m2。We prepared poly[2-(2-ethylhexyloxy)-5-methoxy-1,4-phenylene vinylene ]-block-poly(2,3-diphenyl-5-octyl-p-phenylene vinylene(MEH-PPV-block- DPO-PPV) with MEH-PPV and DPO-PPV chain segments by Wittig-Horner reaction in this research . When this two polymer chian segments reach the saturation of conjugation length, it make diblock copolymer have better luminescence efficiency than pure MEH-PPV and DPO-PPV.Besides, we also prepared pure MEH-PPV and DPO-PPV for comparison . We used NMR to characterize these three polymer structures and DSC 、TGA to investigate their thermal properties. We synthesized successfully MEH-PPV 、DPO-PPV and their diblock copolymer by controlling the reaction temperature and time.In THF solution, DPO-PPV appeared blue-green,MEH-PPV orange-red and MEH-PPV-block- DPO-PPV yellow.The three polymers all exhibited bright photoluminescence.Wittig-Horner reaction is the condensation reaction of aldehyde and phosphonate ,but can’t synthesize higher molecular weight.Polymer with small molecular weight can’t form smooth film after spin coating instead the film had molecular defects that would affect luminous properties. As we fabricated polymer light emitting diodes(PLED),MEH-PPV has turn-on voltage at 3.9V and the largest luminance of 102 cd/m2 at 12.2V.MEH-PPV-block-DPO-PPV has the best efficiency among three polymers with the turn-on voltage at 3.1V,and has the bright luminance of 525cd/m2 at 9V.中文摘要...................................................... I 英文摘要..................................................... II 目錄........................................................ III 圖索引........................................................ V 第一章 緒論.................................................. 1 1-1 前言................................................... 1 1-2 研究目標............................................... 1 1-3 發光原理............................................... 3 1-3-1 共軛系統.......................................... 3 1-3-2 發光機構.......................................... 3 1-4 文獻回顧.............................................. 4 第二章 實驗.................................................. 8 2-1 試藥.................................................. 8 2-2 合成方法.............................................. 9 2-2.1利用Witti-Horner reaction聚合MEH-PPV............. 9 2-2.2利用Witti-Horner reaction聚合DPO-PPV............. 12 2-2.3利用Witti-Horner reaction來得到DPO-PPV與MEH-PPV的 共聚物........................................... 15 2-3 性質測試............................................. 16 2-3-1 凝膠滲透層析儀................................... 16 2-3-2 核磁共振光譜儀................................... 16 2-3-3 紫外可見光吸收光譜儀............................. 17 2-3-4 螢光光譜儀....................................... 17 2-3-5 熱重分析儀....................................... 17 2-3-6 熱±微差掃瞄卡計................................... 17 2-3-7 雙光子雷射共軛焦顯微鏡........................... 18 2-3-8 高分子電激發光元件............................... 18 第三章 結果與討論........................................... 19 3-1 共聚物含量分析....................................... 19 3-1-1不同溶劑中Wittig反應測試......................... 19 3-1-2聚合物之GPC圖譜分析.............................. 19 3-1-3共聚物含量分析.................................... 20 3-2聚合物之熱性質分析.................................... 22 3-2-1 TGA測試.......................................... 22 3-2-2 DSC測試.......................................... 23 3-3聚合物之UV-VIS光譜與PL光譜之分析.................... 23 3-3-1 UV-VIS吸收光譜................................... 23 3-3-2放射光譜.......................................... 24 3-4 聚合物之電化學....................................... 26 3-5 雙光子螢光顯微鏡圖................................... 26 3-6 電激發光光譜圖....................................... 27 3-7 L-V-I圖.............................................. 27 第四章 結論................................................. 29 參考文獻..................................................... 30 圖一：幾種常見的共軛高分子................................... 35 圖二：PL與EL發光機制的示意圖................................ 36 圖三：發光二極體元件......................................... 36 圖四：MEH單體合成反應步驟機構圖.............................. 37 圖五：DPO單體合成反應步驟機構圖.............................. 38 圖六：MEH-PPV合成流圖........................................ 39 圖七：DPO-PPV合成流圖........................................ 39 圖八：MEH-PPV-block-DPO-PPV合成流程圖........................ 40 圖九：化合物一氫譜............................................ 41 圖十：化合物二氫譜............................................ 41 圖十一：化合物三氫譜......................................... 42 圖十二：化合物四氫譜......................................... 42 圖十三：化合物五氫譜......................................... 43 圖十四：化合物六氫譜......................................... 43 圖十五：化合物七氫譜......................................... 44 圖十六：化合物八氫譜......................................... 44 圖十七：化合物九氫譜......................................... 45 圖十八：化合物十氫譜......................................... 45 圖十九：化合物十一氫譜....................................... 46 圖二十：化合物十二氫譜....................................... 46 圖二十一：化合物十三氫譜...................................... 47 圖二十二：化合物十四氫譜..................................... 47 圖二十三：化合物十五氫譜..................................... 48 圖二十四：化合物十五的放大氫譜............................... 48 圖二十五：以Wittig反應不同溶劑聚合DPO-PPV的GPC圖譜........ 49 圖二十六：DPO-PPV、MEH-PPV及Block copolymer的GPC圖譜....... 49 圖二十七：Block copolymer與其Oligomers的GPC圖.............. 50 圖二十八：DPO-PPV液態UV吸收光譜............................. 50 圖二十九：共聚物在UV350nm及UV480nm吸收所得GPC圖........... 51 圖三十：MEH-PPV液態UV吸收光譜............................... 51 圖三十一：MEH-PPV與DPO-PPV同濃度下的液態UV吸收光譜........... 52 圖三十二：DPO-PPV、MEH-PPV及Block copolymer的TGA圖譜....... 52 圖三十三：DPO-PPV的DSC圖譜.................................. 53 圖三十四：MEH-PPV的DSC圖譜.................................. 53 圖三十五：Block copolymer的DSC譜............................. 54 圖三十六：DPO-PPV、MEH-PPV及Block copolymer的液態UV吸收光譜. 54 圖三十七：DPO-PPV、MEH-PPV及Block copolymer的固態UV吸收光譜. 55 圖三十八：DPO-PPV、MEH-PPV及Block copolymer在10-4M THF溶液PL放 射光譜............................................. 55 圖三十九：DPO-PPV、MEH-PPV及Block copolymer在10-4M Toluene溶液PL放射光譜......................................... 56 圖四十：DPO-PPV、MEH-PPV及Block copolymer在10-4M Chloroform溶液 PL放射光譜........................................... 56 圖四十一：DPO-PPV在10-4M的不同溶液PL放射光譜.................. 57 圖四十二：MEH-PPV在10-4M的不同溶液PL放射光譜................ 57 圖四十三：Block copolymer在10-4M的不同溶液PL放射光譜......... 58 圖四十四：不同濃度的DPO-PPV液態PL放射光譜................... 58 圖四十五：Normalized後的不同濃度DPO-PPV液態PL放射光譜...... 59 圖四十六：不同濃度的MEH-PPV液態PL放射光譜.................. 59 圖四十七：Normalized後的不同濃度MEH-PPV液態PL放射光譜...... 60 圖四十八：不同濃度的Block copolymer液態PL放射光譜.......... 60 圖四十九：Normalized後的不同濃度Block copolymer液態PL放射光 譜................................................. 61 圖五十：DPO-PPV、MEH-PPV及Block copolymer的固態PL放射光譜... 61 圖五十一：內標準ferrocene/ferrocenium的C V圖............... 62 圖五十二：DPO-PPV、MEH-PPV及Block copolymer的C V圖......... 62圖五十三：雙光子雷射共軛焦顯微鏡圖............................ 63 圖五十四：DPO-PPV的EL光譜圖................................ 63 圖五十五：MEH-PPV的EL光譜圖................................. 64 圖五十六：Block copolymer的EL光譜圖......................... 64 圖五十七：MEH-PPV、DPO-PPV、及Block copolymer的電流對電壓圖.. 65 圖五十八：MEH-PPV、DPO-PPV及MEH-PPV-block-DPO-PPV的亮度對電壓圖................................................. 6