Structural, dielectric, and rheological characterization of thermotropic liquid crystalline copolyesters based on 4-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, terephthalic acid, and isophthalic acid

1991 ◽  
Vol 24 (11) ◽  
pp. 3413-3422 ◽  
Author(s):  
Douglass S. Kalika ◽  
Do Y. Yoon ◽  
Pio Iannelli ◽  
William Parrish
Keyword(s):  
Terephthalic Acid ◽  
Liquid Crystalline ◽  
Isophthalic Acid ◽  
Hydroxybenzoic Acid ◽  
Rheological Characterization

scholarly journals Characterization of New H-Bonded Liquid Crystalline Complexes Based on Iminophenyl Nicotinate

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 499 ◽  
Author(s):  
Rua B. Alnoman ◽  
Mohamed Hagar ◽  
Hoda A. Ahmed ◽  
Khulood A. Abu Al-Ola ◽  
Magdi M. Naoum ◽  
...  
Keyword(s):  
Terephthalic Acid ◽  
Density Functional ◽  
Liquid Crystalline ◽  
Uv Spectroscopy ◽  
Isophthalic Acid ◽  
Geometrical Parameters ◽  
Scanning Calorimetry ◽  
Acid Complex ◽  
Smectic A

Two new 1:2 supramolecular H-bonded liquid crystalline complexes (SMHBCs) were prepared through double H-bond interactions between either isophthalic acid (A) or terephthalic acid (B) and a nicotinate Schiff base (I6). The formed complexes were thermally investigated by differential scanning calorimetry (DSC), and their phases were identified by polarized optical microscopy (POM) and UV-spectroscopy. The formation of 1:2 hydrogen-bonded complexes was confirmed through their Fermi-bands observed by FT-IR spectroscopy. The first system (I6/A) was found to possess enantiotropic smectic A and nematic mesophases. Induced broad range of smectic A phase was observed in I6/A complex which is not shown by their individual components. The second complex system (I6/B) was purely nematogenic. Density functional theory (DFT) calculations were applied to predict their geometrical parameters. Theoretical studies revealed that the isophthalic complex adopted the W-shape; while the U-shape was adopted by the terephthalic acid complex (I6/B). The linear geometry of the complex based on the isophthalic acid enhanced the mesomorphic behavior observed by the terephthalic complex; I6/B. Actually; the orientation of the two carboxylic groups was shown to highly affect the softness of the derived complex. On the other hand; the mapping orientation of the charge distribution can be used to explain the mesophase behavior. The photophysical characterization of isophthalic complex (I6/A) is also discussed

Polymorphism in a liquid crystalline polyester based on 4,4'-biphenol, terephthalic acid, and p-hydroxybenzoic acid (1:1:2)

1988 ◽  
Vol 21 (7) ◽  
pp. 2155-2160 ◽  
Author(s):  
N. D. Field ◽  
R. Baldwin ◽  
R. Layton ◽  
P. Frayer ◽  
F. Scardiglia
Keyword(s):  
Terephthalic Acid ◽  
Liquid Crystalline ◽  
Hydroxybenzoic Acid ◽  
Liquid Crystalline Polyester

scholarly journals Liquid Crystalline Properties of the Copolyesters Prepared from Resorcinol, p-Hydroxybenzoic Acid, and Terephthalic Acid

1989 ◽  
Vol 21 (8) ◽  
pp. 615-622 ◽  
Author(s):  
Jung-Il Jin ◽  
Suck-Hyun Lee ◽  
Ho-Jin Park ◽  
Il-Joong Kim
Keyword(s):  
Terephthalic Acid ◽  
Liquid Crystalline ◽  
Hydroxybenzoic Acid
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