利用鏈接組合式化學合成聚噻吩系之共聚合物研究

Abstract

本篇論文中，我們將多臂鏈星狀高分子與導電性高分子的末端基進行改質，並利用click chemistry 將兩者結合成為核殼型共聚合導電性高分子。首先，利用有機金屬錯合物偶合反應來聚合出線性的聚3-己烷基噻吩(P3HT)，並透過一個三鍵的抑制劑來終止反應，使得P3HT 末端帶有三鍵之結構。接著分別合成出三、六、十二臂鏈的起始劑，利用原子自由基轉移聚合法(atom transfer radical polymerization,ATRP) 來合成聚丙烯酸甲酯(PMA) ， 再以 trimethylsilylazide 將末端基改質成為N3。最後透過click reaction 將多臂鏈星狀PMA 與P3HT 結合，形成核殼型共聚合導電性高分子。我們透過紅外線光譜儀(FT-IR)、核磁共振光譜儀(1H & 13C NMR)、凝膠滲透層析儀(GPC)以及基質輔助雷射脫附游離飛行時間質譜儀(MALDI-TOF)來鑑定其分子結構與分子量。 此核殼型共聚合導電性高分子對於氯仿的溶解度很好，紫外線-可見光吸收光譜(UV-vis)中最大吸收峰為450nm，而光激螢光光譜(PL)而最大放光波長為575nm。由UV-vis 與PL 圖譜的比較我們發現核殼型共聚合導電性高分子仍具有與純導電性高分子相同之光學性質。

A novel route for preparing poly(3-hexylthiophene)-based core shell like copolymer via click chemistry approach has been developed. First, regioregular ethynyl group ended poly(3-hexylthiophene)s (P3HT) were synthsized using a ethynyl-terminated Grignard reagent. Then, multifunctional initiators for atom transfer radical polymerization (ATRP) were prepared by reacting molecules containing three, six, or twelve hydroxyl groups with 2-bromoisobutyryl bromides to yield the corresponding 2-bromoisobutyrates moiety. The starburst poly(methyl acrylate)s (PMA) were produced by using these initiators in a controlled manner by ATRP, and the ω-bromo ends of these star polymers were subsequently modified to generate the same number of azide functional groups in the presence of trimethylsilylazide (TMS-N3). Finally, the PMA core and P3HT shell were combined to form core shell like diblock copolymers by click reaction. Chemical structure and molecular weight characteristics of these copolymers were studied by IR、1H & 13C NMR、GPC and MALDI-TOF techniques. The core shell like diblock copolymers were well soluted in chloroform. The UV-visible absorption spectra (UV-vis) showed the λmax=450nm, and the photoluminescence spectra (PL) showed the light emission wavelength were about 575nm. By comparing the UV-vis and PL spectra, the optical properties of these copolymers are the same as pure P3HT.