Synthesis and Characterization of a Combined Main-Chain/Side-Chain Liquid-Crystalline Polymer Exhibiting Both Thermotropic and Lyotropic Characteristics and Its Lyotropic Phase Behavior
作者:Ming Zhou、Chang Dae Han
DOI:10.1021/ma050656i
日期:2005.11.1
nematic mesophase, and PSHQ4−7CNCOOH exhibits boththermotropic and lyotropic characteristics. The thermotropic characteristics of PSHQ4−7CNCOOH have been investigated using differential scanning calorimetry (DSC), fiber and powder patterns of wide-angle X-ray diffraction (WAXD), and polarized optical microscopy (POM). It has been found that in the thermotropic state PSHQ4−7CNCOOH has a glass transition
Aromatic poly(ether ester)s derived from a naturally occurring building block nipagin and linear aliphatic α,ω-diols
作者:Keling Hu、Dongping Zhao、Guolin Wu、Jianbiao Ma
DOI:10.1039/c7ra01810j
日期:——
Nipagin, the methyl ester of p-hydroxybenzoic acid, which is present naturally in campanulaceae and ericaceous plants, was used to prepare poly(etherester)s. In this study, two nipagin-based aromatic dimethyl esters were synthesized via one-step simple nucleophilic substitutions with methyl chloroacetate and 1,4-dibromobutane, respectively. Subsequently, two series of poly(etherester)s, PN1-ωs and PN2-ωs
尼泊金,的甲酯p -羟基苯甲酸,其为天然存在于桔梗和杜鹃科的植物,被用来制备聚(醚酯)。在这项研究中,分别通过氯乙酸甲酯和1,4-二溴丁烷的一步简单亲核取代反应合成了两种基于尼泊金的芳族二甲基酯。随后,在优化反应条件后,使用线性脂族α,ω-二醇(n = 2、3、4、6、10、12)合成了两个系列的聚醚酯PN1-ωs和PN2-ωs,如进料比,反应催化剂,时间和温度。合成的聚(醚酯)具有重均分子量(M ws)的范围是9300–32 100 g mol -1,并且分散度(D)值在1.5和1.8之间。1 H NMR,13 C NMR和FTIR光谱用于表征其化学结构。通过热重分析(TGA)和差示扫描量热法(DSC)研究热性能。结果表明,基于尼泊金的聚醚酯具有优异的热稳定性,初始分解温度高于350°C,并具有两步降解机理。玻璃化转变温度(T g),熔融和结晶温度(T m,T c)),相应的熔融和结晶焓(ΔH