利用陰離子聚合法以聚吩導電高分子巨起始劑合成聚吩-聚乙烯吡啶嵌段共聚高分子

Abstract

本研究是利用陰離子聚合的方式合成一硬桿-柔曲之嵌段式共聚物(block-copolymer)，並聚合不同比例之嵌段式共聚物，其中硬桿鏈段為聚三己烷基噻吩（P3HT），柔曲鏈段為聚二乙烯吡啶（P2VP）。為了達到這個研究目的，我們先利用格林納置換法合成導電高分子P3HT，再利用陰離子起始劑(TMEDA/s-BuLi)將P3HT尾端鋰化後，加入2-vinylpyridine進行陰離子聚合，形成P2VP-P3HT-P2VP三嵌段共聚物(triblock copolymer)。 合成所得的共聚物分別用凝膠滲透層析儀(GPC)、紫外-可見光光譜(UV-vis)、熱裂解分析(TGA)以及穿透式電子顯微鏡(TEM)來鑑定。從凝膠滲透層析儀的結果我們看到分子量由6.0㎏/mol增加到12.2㎏/mol，在紫外-可見光光譜分析我們可以發現，與純的P3HT相互比較，共聚物有藍移的現象，接著利用穿透式電子顯微鏡觀察其自組裝結構排列情形，可以發現當P3HT比例小時呈現球狀結構。 另外我們也相同的方法嘗試合成不同種類與比例的嵌段式共聚物，改變加入的單體為tert-butyl methacrylate合成PtBMA-P3HT-PtBMA，以期能做更多的分析與應用。

This thesis describes a new method to synthesize rod-coil block copolymers consisting of poly (3-hexyl thiophene) (P3HT) as rigid-rod conducting polymer and poly (2-vinyl pyridine) as flexible coil. Regioregular hydrogen-terminated poly (3-hexyl thiophene)s of well-defined molecular weight were synthesized by using Grignard metathesis of 2,5-dibromo-3-hexyl thiophene monomer followed by the conversion of poly (3-hexyl thiophene) terminal groups to hydrogen. The hydrogen-terminated poly (3-hexyl thiophene)s thus synthesized are metalized with a replacement of end-group hydrogen with lithium by treating a mixture of sec-butyl lithium/N,N,N’,N’-tetramethyl-1,2-ethylenediamine (SBLi/TMEDA) in 1:1 molar ratio in THF. The lithiated poly (3-hexyl thiophene) are found to be an effective macroinitiator for living anionic polymerization of 2-vinyl pyridine (2VP) monomer. The hydrogen-terminated poly (3-hexyl thiophene)s thus synthesized are dissolved in THF and deprotonated by treating the solution with a mixture of sec-butyl lithium/N,N,N’,N’-tetramethyl-1,2-ethylenediamine (SBLi/TMEDA) in 1:1 molar ratio in THF at -40