【摘要】：嵌段共聚物作為高分子研究領域的常青樹,因其特異的性能而被廣泛研究。聚乙烯基咔唑(PVK)是一種重要的聚合物半導體材料,具有良好的空穴傳輸能力,被廣泛應用于光電子領域。將乙烯基咔唑(NVK)與其他功能分子共聚,構建PVK嵌段共聚物,將會賦予PVK新的性能和應用。本論文采用可逆加成-斷裂鏈轉移(RAFT)自由基聚合方法,以聚乙二醇(PEG)大分子RAFT試劑為鏈轉移劑,NVK分別與2-(5-甲氧基-8-羥基喹啉)甲基丙烯酸乙酯(HQHEMA)和N-(2'-甲基丙烯酸乙酯基)-4-(N'-甲基哌嗪基)-1,8-萘酰亞胺(MMPN)共聚,獲得一系列兩親性嵌段共聚物:PEG-b-PVK-co-PHQHEMA、PEG-b-PVK-co-Alq3和PEG-b-PVK-co-PMMPN。用傅里葉變換紅外(FT-IR)光譜、核磁共振氫(1H NMR)譜、高溫凝膠色譜(GPC)、紫外-可見光(UV-Vis)吸收光譜、光致發(fā)光(PL)譜和熱重分析(TGA)對聚合物的結構和性能進行了表征。(1)合成兩種聚合單體:HQHEMA、MMPN。合成出小分子RAFT試劑:S-正十二烷基-S'-(α,α'-二甲基-丙烯酸)-三硫代碳酸酯(DDAT)和大分子RAFT試劑PEG-DDAT。用1H NMR與FT-IR譜確認了化合物的化學結構。(2)通過調控聚合溫度、投料比和加料方式,優(yōu)化NVK聚合條件。在PEG-DDAT調控下,將NVK與HQHEMA共聚,合成出一系列雙親嵌段共聚物:PEG-b-PVK-co-PHQHEMA。用1HNMR和FT-IR 譜對PEG-b-PVK-co-PHQHEMA的結構進行表征。GPC結果表明獲得的嵌段共聚物的分子量分布系數(shù)低于1.3,表明該RAFT聚合方法可有效地控制聚合物的分子量分布。通過1HNMR譜分析計算出共聚結構單元在共聚物中摩爾分數(shù),并對理論分子量、GPC測得的分子量以及通過1HNMR計算的分子量進行了分析。(3)利用制備的嵌段共聚物PEG-b-PVK-co-PHQHEMA與二喹啉合鋁(Pr-i-O-Alq2)螯合形成共聚物PEG-b-PVK-co-Alq3。該共聚物的紅外光譜發(fā)現(xiàn)鋁氧鍵的存在,其強度隨著HQHEMA結構單元含量的增加而增強。TGA結果表明該共聚物的熱分解溫度超過330℃。由于共聚物在二氯甲烷(DCM)和乙醇中溶解性的差異,在兩種溶劑中呈現(xiàn)出不同鏈構象,共聚物表現(xiàn)出不同的發(fā)光性質。(4)采用RAFT自由基聚合方法將NVK與MMPN共聚,制備出共聚物PEG-b-PVK-co-PMMPN。用1HNMR、GPC和FT-IR譜表征共聚物的化學結構并獲得MMPN和NVK結構單元在共聚物中的平均組成。由于PVK與萘酰亞胺之間共振能量轉移,320nm光激發(fā)時,萘酰亞胺的熒光強度增加。探討pH值和金屬離子對PEG-b-PVK-co-PMMPN的發(fā)光性能影響,發(fā)現(xiàn)共聚物在四氫呋喃溶液中對Cu2+有選擇性識別。由于共聚物在水中聚集,PVK與萘酰亞胺之間共振能量轉移效率增加,萘酰亞胺的熒光強度顯著增加,然而共聚物失去對金屬離子的識別。
[Abstract]:Block copolymers are widely studied because of their specific properties as evergreen trees in polymer research field. Poly (vinyl carbazole) (PVK) is an important polymer semiconductor material with good hole transport ability and has been widely used in the field of optoelectronics. The copolymerization of vinyl carbazole (NVK) with other functional molecules to construct PVK block copolymers will give PVK new properties and applications. In this paper, the reversible addition-fragmentation chain transfer (RAFT) radical polymerization method was used, and polyethylene glycol (PEG) macromolecule RAFT reagent was used as chain transfer agent. NVK was copolymerized with 2-(5-methoxy-8-hydroxyquinoline) ethyl methacrylate (HQHEMA) and N-(2-methoxy-ethyl acrylate)-4-(Na-methylpiperazinyl)-1,8-naphthalimide (MMPN), respectively, with 2-(5-methoxy-8-hydroxyquinoline) ethyl methacrylate. Preparation of a series of amphiphilic block copolymers: PEG-b-PVK-co-PHQHEMA,PEG-b-PVK-co-Alq3 and PEG-b-PVK-co-PMMPN. Fourier transform infrared (FT-IR) spectra, nuclear magnetic resonance hydrogen (1H NMR) spectra and high temperature gel chromatography (GPC),) ultraviolet-visible light (UV-Vis) absorption spectra were used. The structure and properties of the polymers were characterized by photoluminescence (PL) spectroscopy and thermogravimetric analysis (TGA). (1) two kinds of polymerized monomers: HQHEMA,MMPN. were synthesized. The small molecule RAFT reagent: s-dodecyl-SS-(偽, 偽'- dimethyl-acrylic acid)-trithiocarbamate (DDAT) and macromolecule RAFT reagent PEG-DDAT. were synthesized. The chemical structure of the compound was confirmed by 1H NMR and FT-IR spectra. (2) the conditions of NVK polymerization were optimized by adjusting the polymerization temperature, feed ratio and feeding mode. A series of amphiphilic block copolymers (PEG-b-PVK-co-PHQHEMA.) were synthesized by copolymerization of NVK with HQHEMA under the control of PEG-DDAT. The structure of PEG-b-PVK-co-PHQHEMA was characterized by 1HNMR and FT-IR spectra. GPC results showed that the molecular weight distribution coefficient of the block copolymer was lower than 1.3, which indicated that the RAFT polymerization method could effectively control the molecular weight distribution of the polymer. The molar fraction of the copolymer structure unit in the copolymer was calculated by 1HNMR spectrum analysis, and the molecular weight of the copolymer was calculated. The molecular weight measured by GPC and calculated by 1HNMR were analyzed. (3) the block copolymer PEG-b-PVK-co-PHQHEMA was chelated with diquinoline aluminum (Pr-i-O-Alq2) to form the copolymer PEG-. B / PVK / Alq3. The IR spectra of the copolymer show that the Al-O bond exists and the strength of the copolymer increases with the increase of the content of HQHEMA structural units. The results show that the thermal decomposition temperature of the copolymer is more than 330 鈩，

本文編號：2445349