Please use this identifier to cite or link to this item:
https://doi.org/10.1080/02678290410001709266
Title: | Molecular design of liquid crystalline poly(ester-amide)s with perfluoroalkyl spacers | Authors: | Teoh, M.M. Chung, T.-S. Cheng, S.-X. Lin, T.T. Pramoda, K.P. |
Issue Date: | Jun-2004 | Citation: | Teoh, M.M., Chung, T.-S., Cheng, S.-X., Lin, T.T., Pramoda, K.P. (2004-06). Molecular design of liquid crystalline poly(ester-amide)s with perfluoroalkyl spacers. Liquid Crystals 31 (6) : 871-881. ScholarBank@NUS Repository. https://doi.org/10.1080/02678290410001709266 | Abstract: | We have introduced a series of perfluoroalkyl dicarboxylic acids with different lengths of fluorinated aliphatic segments into the 2,6-acetoxynaphthoic acid (ANA) and acetoxy acetanilide (AAA) systems; and their effects on the evolution of liquid crystal texture and liquid crystallinity have been investigated. The perfluoroalkyl dicarboxylic acids are tetrafluorosuccinic acid (TFSA, n = 2), hexafluoroglutaric acid (HFGA, n = 3), perfluorosuberic acid (PFSUA, n = 6) and perfluorosebacic acid (PFSEA, n = 8). Computational results based on the 'RIS' Metropolis Monte Carlo method indicate that the ANA/AAA/perfluoroalkyl system may form thermotropic liquid crystalline polymers (LCPs) because the calculated persistence ratios are greater than 6.42. Computational results also predict that the systems containing even-numbered perfluoroalkyl acids have greater persistence length and molar stiffness than that containing odd-numbered acids. Experiments were carried out using the in situ thin film polymerization technique under a polarizing optical microscope. We observed that systems containing short aliphatic units (n = 2, 3) tend to remain in the LC phase, while systems containing a long aliphatic spacer (n = 8) tend to crystallize during the late stage of the polycondensation reaction. The liquid crystal domain formed in the early stage has a disclination strength S of + 1. Ternary phase diagrams were plotted to show the relationship among monomer structure, composition, anisotropic and crystalline phases. FTIR results confirm the formation of LCPs. | Source Title: | Liquid Crystals | URI: | http://scholarbank.nus.edu.sg/handle/10635/89468 | ISSN: | 02678292 | DOI: | 10.1080/02678290410001709266 |
Appears in Collections: | Staff Publications |
Show full item record
Files in This Item:
There are no files associated with this item.
SCOPUSTM
Citations
3
checked on Jan 18, 2021
WEB OF SCIENCETM
Citations
3
checked on Jan 18, 2021
Page view(s)
70
checked on Jan 18, 2021
Google ScholarTM
Check
Altmetric
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.