Thermally Induced Pitch Gradients in Side-Chain Cholesteric Liquid Crystalline Polymers

2011 ◽  
Vol 311-313 ◽  
pp. 1323-1326
Author(s):  
Jiu Mei Xiao ◽  
Li Long Yu ◽  
Dong Yu Zhao ◽  
Wan Li He ◽  
Hui Cao ◽  
...  

It is reported that a pitch gradient is formed in a side chain cholesteric liquid crystalline polymer (ChLCP) through a novel method. Heating up the ChLCP within the temperature range of the cholesteric (Ch) phase leads to the first availability of its planar texture. Then, the ChLCP film with the planar texture is cooled down to its glassy (G) state in line with the temperature difference between the upper and the bottom substrates. The SEM image indicates clearly a pitch gradient perpendicular to the substrates, and the results of transmission spectra show that the reflective bandwidth of the ChLCP film with the pitch gradient is greatly broadened.

2014 ◽  
Vol 131 (19) ◽  
pp. n/a-n/a
Author(s):  
Wen-Zhi Zhao ◽  
Yue-Hua Cong ◽  
Bao-Yan Zhang ◽  
Wei-Min Gu

2011 ◽  
Vol 181-182 ◽  
pp. 197-200
Author(s):  
Yu Lei Zhao ◽  
Wei Min Zhang ◽  
Ji Lei Li ◽  
Fan Fan Yu ◽  
Jia Ling Pu

A new type of able liquid crystalline polymer with a coumarin-containing mesogenic side group that could be photo-crosslinked was synthesized in this paper. The structure of the intermediates, monomers and polymers were characterized with FTIR and 1HNMR measurement. DSC, TG, and hot stage polarized optical microscopy were employed to study the phase transition temperature, mesophase texture, and thermal stability of the liquid crystalline polymers. The results indicated that both the monomer and polymer exhibited liquid-crystalline features over a wide temperature range.


RSC Advances ◽  
2015 ◽  
Vol 5 (118) ◽  
pp. 97187-97194 ◽  
Author(s):  
He-lou Xie ◽  
Bin Ni ◽  
Quan Liu ◽  
Jun Wang ◽  
Shuang Yang ◽  
...  

A series of combined main-chain/side-chain liquid crystalline polymers based on the “jacketing” effect, with different alkyl spacer lengths (n = 2–10), have been successfully synthesized and their self-organization behavior has been investigated.


Author(s):  
Linda C. Sawyer

Recent liquid crystalline polymer (LCP) research has sought to define structure-property relationships of these complex new materials. The two major types of LCPs, thermotropic and lyotropic LCPs, both exhibit effects of process history on the microstructure frozen into the solid state. The high mechanical anisotropy of the molecules favors formation of complex structures. Microscopy has been used to develop an understanding of these microstructures and to describe them in a fundamental structural model. Preparation methods used include microtomy, etching, fracture and sonication for study by optical and electron microscopy techniques, which have been described for polymers. The model accounts for the macrostructures and microstructures observed in highly oriented fibers and films.Rod-like liquid crystalline polymers produce oriented materials because they have extended chain structures in the solid state. These polymers have found application as high modulus fibers and films with unique properties due to the formation of ordered solutions (lyotropic) or melts (thermotropic) which transform easily into highly oriented, extended chain structures in the solid state.


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