Title: An Azoester-containing Photoresponsive Linear Liquid Crystal Polymer with Good Mesophase Stability

Author: Shuqiang Han, Yingying Chen, Bo Xu, Jia Wei*, Yanlei Yu

Journal: Chinese J. Polym. Sci., 2020, 38, 806–813 (Cover Page)

Abstract:

Photoresponsive linear liquid crystal polymers (LLCPs) are attractive because of the excellent stimuli-responsibility and the good processability. In this study, a new photoresponsive LLCP containing azoester (PC11AE6) with good mesophase stability was synthesized by ring-opening metathesis polymerization. By introducing photoresponsive azoester mesogenic unit, which has high rigidity and a large length-diameter ratio, the resultant polymer possesses abroad mesophase temperature interval (isotropic temperature = 180 °C). A study on mesophase by 2D-wide angle X-ray diffraction indicated that the mesogens were orientated spontaneously into smectic A phase after annealing. The orientated films and fibres exhibited macroscopic, rapid and reversible deformations under light irradiation as a result of the photoisomerization of azoester as confirmed by UV-Vis absorption spectrophotometry. We anticipate that this work provides a strategy for preparing LLCP with a broad mesophase temperature range, which is positive for potential applications.

Fulltext Link: https://link.springer.com/article/10.1007%2Fs10118-020-2383-0

In this study, a new photoresponsive LLCP containing azoester (PC11AE6) was synthesized by ring-opening metathesis polymerization. By introducing photoresponsive azoester mesogenic unit, which has high rigidity and a large length-diameter ratio, the resultant polymer possesses a broad mesophase temperature interval (isotropic temperature = 180 °C). Due to the spontaneous orientation ability of polymer, PC11AE6 films and fibres possessed anisotropic structures with smectic A phase at room temperature and smectic C phase at elevated temperatures. Meanwhile, with out-of-plane orientation of mesogens, the PC11AE6 films bent away from the UV source and unbent completely under visible light irradiation.