Thermal Properties of Liquid-Crystalline Diols and Corresponding Bis-Urethanes with Mesogenic Groups of Various Structures in Side Chains
摘要:
The liquid-crystalline diols with mesogenic groups of different structures were synthetized and their temperature behavior and existence of mesophases were determined. These compounds were also reacted with phenylisocyanate to form bis-urethanes at the ratio of reactive groups [OH]/[NCO] = 1/1. The changes of phase transition temperatures due to the change of H-O-H to H-N-H interactions have been investigated. Generally, the introduction of a phenylurethane group into the molecule suppresses the occurence of mesophases; in the case of simple mesogens the mesophases disappear completely. Stiff substituents bound to mesogen as end groups (such as the phenyl group, alkoxy group, etc.) stabilize the mesophases to such a degree that the negative influence of urethane group is compensated and the LC properties are recovered.
Thermotropic and lyotropic behavior of novel amphiphilic liquid crystals having hydrophilic poly(ethyleneimine) units
作者:Seiji Ujiie、Yumi Yano
DOI:10.1039/a907765k
日期:——
Novel ionic amphotropic liquid crystals, in which a hydrophilic poly(ethyleneimine) chain with hydroxy side-groups was attached to an azobenzene mesogenic core through an alkylene chain, showed a thermotropic smectic A mesophase and lyotropic smectic A and C mesophases.
新型离子型两性液晶,其中具有羟基侧基的亲水性聚(乙烯亚胺)链通过亚烷基链连接到偶氮苯介晶核,显示出热致近晶 A 中间相和易溶近晶 A 和 C 中间相。
Phase Transitions of Side Chain Liquid Crystal Polyamines
作者:Yumi Yano、Seiji Ujiie、Akira Mori
DOI:10.1080/10587250108025302
日期:2001.7.1
Synthesis and liquid crystalline properties of a disc-shaped molecule with azobenzene at the periphery
triphenylene-based novel liquid crystal was synthesised whose peripheral cores are six rod-like azobenzene moieties linked through alkyl chains. A disc-shaped molecule 2,3,6,7,10,11-hexakis-[4-(4-nitrophenylazo)phenoxy}hexyloxy]triphenylene was prepared by using a ferric chloride oxidative trimerisation of 1,2-bis-[4-(4-nitrophenylazo)phenoxy}hexyloxy]benzene. Differential scanning calorimetry and polarising optical microscopy analysis revealed the existence of a nematic mesophase. (c) 2005 Elsevier Ltd. All rights reserved.
Liquid Crystalline Properties and Orientational Structure of Binary Systems Built from Poly(Vinylalcohol) and Amphiphilic Compound