Main-chain azo polyaramides with high thermal stability and liquid crystal properties
| Autor: | Lijie Dong, Chuanxi Xiong, Yanjiao You, Zhengguang Sun, Youan Lei, Junlong Yao |
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| Rok vydání: | 2008 |
| Předmět: |
Condensation polymer
Materials science Polymers and Plastics Organic Chemistry Photochemistry Crystal Photochromism chemistry.chemical_compound Azobenzene chemistry Lyotropic liquid crystal Liquid crystal Materials Chemistry Physical chemistry Thermal stability Fourier transform infrared spectroscopy |
| Zdroj: | Journal of Polymer Research. 16:455-460 |
| ISSN: | 1572-8935 1022-9760 |
| DOI: | 10.1007/s10965-008-9248-5 |
| Popis: | Two novel main-chain aromatic polyamides containing azobenzene were synthesized by polycondensation of trans-azobenzene-4,4′-dicarbonyl chloride with various aromatic diamines under low temperature. Their molecular structures were identified to be symmetric and regular by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and elemental analysis. Polymers exhibited not only high thermal stability, but also lyotropic liquid crystal (LC) phases in N,N-dimethylacetamide solution which is due to hydrogen bonding and an ordered rigid structure. The crystal behaviours of the polymers were studied with X-ray diffraction analysis, and the photochromism was investigated with an ultraviolet–visible spectrophotometer with 365 nm ultraviolet irradiation. An abnormal change of the crystal behavior and thermal stability of polymer was found to be related with molecular structure containing ether linkage. The azo polyaramides can be applied in fields of optical techniques and potential photochromics fibres spinning in wide temperature ranges |
| Databáze: | OpenAIRE |
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