本文選題：苯并菲側(cè)鏈型液晶高分子 + 空間效應(yīng)　； 參考：《湘潭大學(xué)》2017年碩士論文

【摘要】：近年來(lái),苯并菲側(cè)鏈型液晶高分子(Tp SCLCPs)的液晶機(jī)理受到了廣泛的關(guān)注,越來(lái)越多的研究表明Tp SCLCPs的相行為有著獨(dú)特的液晶機(jī)理。但是,科研工作者較少研究苯并菲的空間效應(yīng)對(duì)側(cè)鏈型高分子相行為的影響。對(duì)此,該文通過(guò)增長(zhǎng)苯并菲的烷烴尾鏈長(zhǎng)度,以此增加苯并菲盤(pán)狀側(cè)基的固有空間體積(本身分子結(jié)構(gòu)所具有的體積)。本文從主鏈類(lèi)型和間隔基長(zhǎng)度這兩個(gè)方面來(lái)調(diào)控苯并菲盤(pán)狀側(cè)基對(duì)主鏈空間效應(yīng)的強(qiáng)弱,通過(guò)DSC,POM,1D/2D WAXD和SAXS全面考察側(cè)基空間效應(yīng)的強(qiáng)弱對(duì)Tp SCLCPs相行為和相結(jié)構(gòu)的影響。主要的研究如下:1.設(shè)計(jì)并合成了一系列不同主鏈結(jié)構(gòu)的無(wú)柔性間隔基長(zhǎng)烷烴尾鏈Tp SCLCPs。通過(guò)1H NMR和質(zhì)譜確定單體的化學(xué)結(jié)構(gòu)。通過(guò)DSC、POM、1D/2D WAXD和SAXS對(duì)其相行為和相結(jié)構(gòu)進(jìn)行一系列的表征。其研究結(jié)果表明,不同主鏈結(jié)構(gòu)對(duì)液晶高分子的相行為有著重要的影響。由于側(cè)基強(qiáng)大的空間效應(yīng)以及主鏈與苯并菲側(cè)基之間的耦合作用,所有聚合物都能形成由主鏈和側(cè)基一起構(gòu)筑的柱狀結(jié)構(gòu),但是他們的柱狀的排列方式會(huì)隨主鏈的變化而變化,當(dāng)主鏈為聚苯乙烯醚類(lèi)(POTP)以及聚降冰片類(lèi)時(shí)(PNVTP),聚合物表現(xiàn)為六方柱狀相。以聚甲基丙烯酸酯類(lèi)(PMMTP)和聚丙烯酸酯(PMTP)為主鏈的聚合物形成柱狀向列相。以聚苯乙烯酯類(lèi)(PSTP)為主鏈時(shí)形成四方柱狀相。此外,清亮點(diǎn)(Ti)的溫度也會(huì)隨著主鏈的變化而變化,通過(guò)觀察,發(fā)現(xiàn)PMMTP的超過(guò)300℃。2.設(shè)計(jì)并合成一系列不同間隔基長(zhǎng)度的長(zhǎng)烷烴尾鏈Tp SCLCPs,簡(jiǎn)稱為P-m-TP(m為其間隔基亞甲基的個(gè)數(shù),m=2、3、4、6和8)。通過(guò)1H NMR和質(zhì)譜確定單體的化學(xué)結(jié)構(gòu)。通過(guò)DSC,POM,1D WAXD和SAXS對(duì)其相行為和相結(jié)構(gòu)進(jìn)行表征。實(shí)驗(yàn)結(jié)果表明:側(cè)基空間效應(yīng),去偶合效應(yīng)和π-π堆積效應(yīng)的強(qiáng)弱依賴于間隔基長(zhǎng)度的變化。當(dāng)間隔基為2和4時(shí),聚合物在高溫形成由主鏈和側(cè)基一起構(gòu)筑的柱狀向列相,在低溫形成四方柱狀相;當(dāng)間隔基為3時(shí),在整個(gè)液晶溫度范圍內(nèi),聚合物只能形成柱狀向列相。且對(duì)于這些聚合物,它們的Ti均大于300℃,表現(xiàn)出甲殼型液晶高分子的特性。這些結(jié)果表明,即使間隔基較長(zhǎng),側(cè)基空間效應(yīng)依然誘導(dǎo)主鏈和側(cè)基一起形成柱狀結(jié)構(gòu)。當(dāng)間隔基m=6和8時(shí),聚合物形成由側(cè)基苯并菲堆積的六方柱狀相,其Ti分別為108℃和84℃,表現(xiàn)出普通的側(cè)鏈型液晶高分子的性質(zhì)。這些結(jié)果表明,去耦合作用和Tp的π-π堆積作用強(qiáng)于空間效應(yīng),聚合物形成由Tp堆積的柱狀相。
[Abstract]:In recent years, the liquid crystal mechanism of benzphenanthrene side-chain liquid crystal polymers (TP SCLCPs) has been paid more and more attention. More and more studies show that the phase behavior of TP SCLCPs has a unique liquid crystal mechanism. However, researchers seldom studied the effect of the spatial effect of benzophenanthrene on the behavior of side chain polymer phase. In this paper, by increasing the length of the alkane tail chain of benzphenanthrene, the intrinsic space volume (the volume of its molecular structure) of the disk-like side group of benzophenanthrene is increased. In this paper, the main chain type and spacer length are used to regulate the spatial effect of the disklike side group on the main chain. The effects of the side base spatial effect on the phase behavior and phase structure of TP SCLCPs are investigated by DSCP POMN 1D / 2D WAXD and SAXS. The main research is as follows: 1. A series of flexible spacer tail chain (TP SCLCPs) with different main chain structures have been designed and synthesized. The chemical structure of the monomer was determined by 1H NMR and mass spectrometry. The phase behavior and phase structure were characterized by DSC-POMN 1D / 2D WAXD and SAXS. The results show that the phase behavior of liquid crystal polymers is affected by different main chain structures. Due to the strong spatial effect of the side group and the coupling between the main chain and the benzofen side group, all polymers can form columnar structures constructed by the main chain and the side group, but their columnar arrangement will change with the change of the main chain. When the main chain is polystyrene ether (POTP) and polynorborneol (PNVTP), the polymer exhibits hexagonal column phase. Poly (methacrylate) (PMMTP) and polyacrylate (PMTP) were used to form columnar nematic phase. The tetragonal columnar phase was formed when polystyrene esters (PSTP) were used as main chain. In addition, the temperature of the clear bright spot (Ti) also changes with the change of the main chain. Through observation, it is found that the PMMTP is more than 300 鈩，

本文編號(hào)：2074111