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通过脂肪柔性间隔基交替连接制备两种类型主链热致性聚酯液晶

Preparation of main-chain thermotropic polyesters with two types of mesogens connected alternatively by aliphatic spacers

中文摘要英文摘要

以对苯二甲酸-(双-4-酰氯苯酯)(TOBC)、4,4'-双羟烷氧基联苯(n-BP, n = 2, 4, 6)为原料,通过缩聚反应制备了一系列主链型热致性聚酯液晶聚合物(PBTn, n = 2, 4, 6)。对各中间体和PBTn的化学结构进行了FTIR、NMR和元素分析表征。以DSC、热台偏光显微镜(POM)、小角X-ray散射(SAXS)、广角X-ray衍射和热重分析等手段,对 PBTn 的溶解度、液晶织态结构和热学行为进行了系统表征。结果表明,PBTn 的性质与其主链中亚甲基的长度紧密相关,随着亚甲基的长度增加,PBTn 的溶解性得到改善,液晶转变峰变宽,液晶转变点温度降低,热稳定性提高。PBTn 系列中只有PBT4和PBT6显示近晶相的织态结构。

homologous series of main-chain thermotropic polyesters (PBTn, n = 2, 4, 6) containing biphenyl and triad aromatic ester mesogenic units interconnected by n-methylene spacers in the main chain were prepared from terephthaloyl bis(4-oxybenzoyl chloride) (TOBC) and 4,4'-bis(w-hydroxyalkyloxy)biphenyls (n-BP, n = 2, 4, 6) by solution polycondensation. The chemical structures of the monomers and PBTn were characterized by spectroscopic techniques and elemental analysis. The solubility, supermolecular structures, thermal and liquid crystalline properties of PBTn were investigated by differential scanning calorimetry (DSC), polarizing microscopy (PLM), small-angle X-ray scattering (SAXS), thermogravimetric analyses (TGA) and wide-angle X-ray diffraction (WAXD), and they were found to be closely dependent on the length of the methylene spacers. The increasing methylene units led to improved solubility, broader liquid crystalline range, reduced mesophase-isotropic transition point, higher thermal stability and decreasing crystallinity. The decomposition temperatures (5% mass loss) of the polymers were above 380 oC in nitrogen atmosphere and only PBT4 and PBT6 exhibited smectic mesophases as well as high viscosity in the mesophase.

郭卿、黄燕、张保龙、张育英

材料科学高分子化合物工业合成树脂工业、塑料工业

高分子化学(高聚物)液晶聚合物热致性聚酯柔性间隔基

Macromolecule Chemitry (Polymer)Liquid-crystalline polymersthermotropic polyestersFlexible spacers

郭卿,黄燕,张保龙,张育英.通过脂肪柔性间隔基交替连接制备两种类型主链热致性聚酯液晶[EB/OL].(2011-01-14)[2025-08-23].http://www.paper.edu.cn/releasepaper/content/201101-732.点此复制

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