scholarly journals Synthesis and Thermal Characteristic of Liquid Crystalline Polyoxetane Containing Trans-Stilbene Side Group

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 185
Author(s):  
Li-Chuan Wu ◽  
Cheng-Chih Chen ◽  
Chih-Hung Lin
Keyword(s):  
Liquid Crystalline ◽  
Thermal Characteristic ◽  
Side Group ◽  
Spacer Length ◽  
Smectic A ◽  
Trans Stilbene ◽  
Mesogenic Unit ◽  
Cationic Ring Opening Polymerization ◽  
Mesomorphic Properties ◽  
Alkyl Length

A series of fourteen liquid crystalline monomers and polyoxetanes containing trans-biphenyl side group have been successfully synthesized. The thermal and mesomorphic properties of monomers (1M~14M) and polymers (1P~14P) are measured using DSC, POM, and X-ray. All of the series monomers present enantiotropic smectic H and smectic G phase and the series polymers show enantiotropic smectic A phase which three polymers contained exhibit smectic E. Polyoxetanes have been used as a cationic ring-opening polymerization of oxetane monomers bearing a pendant trans-stilbene mesogenic unit including different spacer length and terminal alkyl length.

Syhthesis and Mesomorphic Properties of Side-Chain Liquid-Crystalline Polysiloxanes Exhibiting Spherulite Texture of Polymeric Smectic A Phase

2011 ◽  
Vol 26 (4) ◽  
pp. 437-442
Author(s):  
李颖 LI Ying ◽  
张广成 ZHANG Guang-cheng ◽  
刘斌 LIU Bin ◽  
蒋莹 JIANG Ying ◽  
孙伟民 SUN Wei-min
Keyword(s):  
Liquid Crystalline ◽  
Side Chain ◽  
Smectic A ◽  
Smectic A Phase ◽  
Mesomorphic Properties

scholarly journals Effect of Flexible Chain on Mesomorphic Properties of Alkyloxy Substituted 4-Chloroazobenzene Liquid Crystals

2021 ◽  
Vol 33 (5) ◽  
pp. 1159-1164
Author(s):  
Kamruzzaman ◽  
Roushown Ali ◽  
Rabiul Karim ◽  
Samiul Islam Chowdhury ◽  
Tariqul Hasan
Keyword(s):  
Liquid Crystals ◽  
Optical Microscope ◽  
Scanning Calorimetry ◽  
Flexible Chain ◽  
Spacer Length ◽  
Smectic A ◽  
Alkyl Bromides ◽  
Dsc Analyses ◽  
Azobenzene Derivatives ◽  
Mesomorphic Properties

Three rod-shaped alkyloxy substituted 4-chloroazobenzene liquid crystals, 1-(4-chlorophenyl)-2-[4- (alkyloxy)phenyl]diazene (hexayl, octyl and nonyl as flexible oxyalkyl chain) have been synthesized by diazotization of p-chloroaniline with phenol and subsequently performed etherification reaction with different alkyl bromides. The structures of the substituted 4-chloroazobenzene liquid crystals have been characterized by spectroscopic methods. The mesomorphic properties of the liquid crystals were examined by polarizing optical microscope (POM) and differential scanning calorimetry (DSC). All the oxyalkyl homologues of chloro substituted azobenzene showed enantiotropic smectic A (SmA) mesophase, which was understood clearly by the texture of the compounds employing polarizing optical microscope (POM) analysis. During heating scan in DSC analyses melting points, SmA-isotropic temperature and enthalphy changes associated with SmA-isotropic transition showed a remarkable impact on the spacer length of 4-chloro azobenzene derivatives.

Antibacterial Activity and Mesophase Identification of Azomethnine and Azo derivatives

2021 ◽  
Vol 25 (11) ◽  
pp. 119-131
Author(s):  
Shavi Thakur ◽  
H.N. Patel
Keyword(s):  
Homologous Series ◽  
Liquid Crystalline ◽  
Present Series ◽  
Spectroscopic Methods ◽  
Smectic A ◽  
Polarizability Effect ◽  
Benzene Rings ◽  
Azo Derivatives ◽  
Derivatives Of ◽  
Mesomorphic Properties

A new mesogenic homologous series of liquid crystalline azomethnine and azo derivatives of 4ꞌ-nalkoxybenzylidiene- 4-aminoazobenzene has been synthesized and characterized by a combination of elemental analysis and standard spectroscopic methods. In the present series, nematic mesophase commences from n-propyloxy derivative as enantiotropic and persists up to the last member synthesized except in derivative C10. The smectic A (SmA) mesophases commences from n-pentyloxy derivative as enantiotropic and also persists up to ntetradecyloxy synthesized. Imine linkage (-CH═N-) between central and terminal benzene rings helping to understand the polarizability effect as well as nature of mesophase as stability gets reduced due to the presence of nitrogen in the ring. The mesomorphic properties of present series are of great importance to evaluate the effects of central linkage on mesomorphism. The mesomorphic properties of present series were compared with other structurally related mesogenic homologous series to evaluate the effects of central linkage on mesomorphism.

scholarly journals Ferroelectric liquid-crystalline side group polymers Spacer length variation and comparison with the monomers

1993 ◽  
Vol 14 (3) ◽  
pp. 861-869 ◽  
Author(s):  
K. Kühnpast ◽  
J. Springer ◽  
G. Scherowsky ◽  
F. Gießelmann ◽  
P. Zugenmaier
Keyword(s):  
Liquid Crystalline ◽  
Length Variation ◽  
Side Group ◽  
Spacer Length

Self-organization of cholesterol-side-chain liquid crystalline polymers by tailoring the main chain structure and flexible spacer length

2019 ◽  
Vol 43 (14) ◽  
pp. 5429-5440 ◽  
Author(s):  
Xiwen Yang ◽  
Shaonan Chen ◽  
Hang Luo ◽  
Haoran Xu ◽  
Sheng Chen
Keyword(s):  
Liquid Crystalline ◽  
Main Chain ◽  
Chain Structure ◽  
Self Organization ◽  
Side Chain ◽  
Liquid Crystal Polymers ◽  
Spacer Length ◽  
Crystalline Polymers ◽  
Smectic A ◽  
Flexible Spacer

Liquid crystal polymers with cholesterol side-chains formed different smectic A phases under the influence of the main-chain structure and flexible spacer length.

scholarly journals Liquid Crystalline Benzoic Acid Ester MIDA Boronates: Synthesis and Mesomorphic Properties

2020 ◽  
Vol 02 (04) ◽  
pp. 288-299
Author(s):  
Christopher Schilling ◽  
Finn Schulz ◽  
Andreas Köhn ◽  
Sabine Laschat
Keyword(s):  
Benzoic Acid ◽  
Quantum Chemical ◽  
Liquid Crystalline ◽  
X Ray Diffraction ◽  
Boronate Esters ◽  
X Ray ◽  
Smectic A ◽  
Mesomorphic Properties ◽  
Insight Into ◽  
Acid Esters

Two series of N-methyliminodiacetic acid (MIDA) boronates were prepared and their mesomorphic properties were investigated. MIDA-substituted benzoic acid esters were synthesized via the Mitsunobu reaction. The second series of MIDA benzyl ether derivatives was prepared via Williamson etherification and subsequent borylation. Both series exhibit smectic A (SmA) phases. In the case of MIDA boronate esters, a substitution with perfluorinated side chains led to increased transition temperatures and broadening of the SmA phases. The phase geometries of the mesophases were determined by X-ray diffraction. Quantum-chemical calculations provided further insight into the packing model.

Influence of Chiral Maltose on the Mesomorphic Properties of Main-Chain Liquid-Crystalline Polymers

2012 ◽  
Vol 535-537 ◽  
pp. 1218-1221
Author(s):  
Mei Tian ◽  
Lu Lu Guo ◽  
Dan Shu Yao ◽  
Jian She Hu ◽  
Xiao Zhi He ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Main Chain ◽  
Liquid Crystalline Polymers ◽  
Heating Cycle ◽  
Cooling Cycle ◽  
Crystalline Polymers ◽  
Smectic A ◽  
Heating And Cooling ◽  
Nematic Mesophase ◽  
Mesomorphic Properties

A series of main-chain liquid-crystalline polymers containing maltose were synthesized by interfacial condensation reactions of sebacyl chloride, 4,4’-Dihydroxy-2,2’-dimethyl Benzalazine(DDBA), and 1-O-[4´-O-(α-D-glucopyranosyl)-ß-D-glucopyranosyl]-methanol(MM). The effects of MM on characteristics of liquid-crystalline properties were studied. P1- P3 exhibited nematic mesophase on heating and cooling cycle, while P4- P7 exhibited both chiral smectic A and nematic mesophases on heating cycle and nematic mesophase on cooling cycle. P8 did not exhibit any mesophase on heating and cooling cycle. The glass-transition temperature decreased with increasing concentration of MM.

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