Seo Kyutae, Kang Hyo
BK-21 Four Graduate Program, Department of Chemical Engineering, Dong-A University, 37 Nakdong-Daero 550 Beon-gil, Saha-gu, Busan 604-714, Korea.
Polymers (Basel). 2021 Feb 27;13(5):736. doi: 10.3390/polym13050736.
We synthesized a series of polystyrene derivatives that were modified with precursors of liquid crystal (LC) molecules, such as 4-ethyloxyphenol (homopolymer PEOP and copolymer PEOP#; # = 20, 40, 60, and 80, where # indicates the molar fraction of 4-ethyloxyphenoxymethyl in the side chain), 4--butyloxyphenol (PBOP), 4--hexyloxyphenol (PHOP), and 4--octyloxyphenol (POOP), via polymer modification reaction to investigate the orientation of LC molecules on polymer films, exhibiting part of the LC molecular structure. LC molecules showed a stable and uniform vertical orientation in LC cells fabricated with polymers that have 4-ethyloxyphenoxymethyl in the range of 40-100 mol%. In addition, similar results were obtained in LC cells fabricated with homopolymers of PEOP, PBOP, PHOP, and POOP. The vertical orientation of LC molecules in LC cells fabricated with polymer films correlated to the surface energy of polymer films. For example, vertical LC orientation was observed when the total surface energies of the polymer films were lower than approximately 43.2 mJ/m. Good alignment stabilities were observed at 150 °C and 20 J/cm of ultraviolet irradiation for LC cells fabricated with PEOP film.
我们通过聚合物改性反应合成了一系列用液晶（LC）分子前体改性的聚苯乙烯衍生物，如4-乙氧基苯酚（均聚物PEOP和共聚物PEOP#；# = 20、40、60和80，其中#表示侧链中4-乙氧基苯氧基甲基的摩尔分数）、4-丁氧基苯酚（PBOP）、4-己氧基苯酚（PHOP）和4-辛氧基苯酚（POOP），以研究聚合物薄膜上液晶分子的取向，这些聚合物展现了部分液晶分子结构。在用40 - 100摩尔%范围内含有4-乙氧基苯氧基甲基的聚合物制备的液晶盒中，液晶分子呈现出稳定且均匀的垂直取向。此外，在用PEOP、PBOP、PHOP和POOP的均聚物制备的液晶盒中也获得了类似结果。用聚合物薄膜制备的液晶盒中液晶分子的垂直取向与聚合物薄膜的表面能相关。例如，当聚合物薄膜的总表面能低于约43.2 mJ/m²时，观察到液晶垂直取向。在用PEOP薄膜制备的液晶盒中于150°C和20 J/cm²的紫外线照射下观察到了良好的取向稳定性。
