Wu Yishuo, Shang Guangyang, Ma Cong, Shi Yingjie, Song Zhexu, Wang Peixiang, Gao Yanzi, Wang Qian, Yu Meina, Xiao Jiumei, Zou Cheng
Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China.
Strategic Business Unit of Chlor-Alkali, Sinochem Group, Beijing 100031, China.
Polymers (Basel). 2024 Aug 29;16(17):2446. doi: 10.3390/polym16172446.
Stepwise photopolymerization is a miraculous strategy modulating the polymer skeleton and electro-optical properties of light modulators based on liquid crystal/polymer composites. However, owing to the indistinct polymerization mechanism and curing condition discrepancy, the required polymer structures and electro-optical properties are hard to be controlled precisely. Herein, a novel polymer-stabilized liquid crystal film based on acrylate/epoxy resin is proposed, fabricated and the relationships between preparation process, polymer content, polymer morphology and electro-optical properties are studied. The in-situ photopolymerization of acrylate/epoxy resin liquid crystalline polymer is fulfilled using cation photo-initiator UV 6976. The distinct photopolymerization speed between acrylate and epoxy resin benefits the polymer morphology control, and with accurate containment of the polymerization process and polymer composition, the superior electro-optical properties at a higher polymer content are acquired. The polymer morphology and electro-optical properties are influenced by the polymer content and mass ratio between acrylate and epoxy resin. The best electro-optical properties among samples are attained by controlling the mass ratio between acrylate and epoxy resin to 1:1, integrating higher densities of scattering centers and lower anchoring effect. With higher polymer content, the strategy of increasing the mass ratio of E6M benefits the improvement of E-O properties for alleviating polymer density. This work provides insights to stepwise polymerization of liquid crystalline monomers and offers a fancy strategy for the preparation of novel liquid crystal dimming films.
逐步光聚合是一种神奇的策略，可调节基于液晶/聚合物复合材料的光调制器的聚合物骨架和电光性能。然而，由于聚合机理不明确以及固化条件存在差异，所需的聚合物结构和电光性能难以精确控制。在此，我们提出并制备了一种基于丙烯酸酯/环氧树脂的新型聚合物稳定液晶薄膜，并研究了制备工艺、聚合物含量、聚合物形态与电光性能之间的关系。使用阳离子光引发剂UV 6976实现了丙烯酸酯/环氧树脂液晶聚合物的原位光聚合。丙烯酸酯和环氧树脂之间明显不同的光聚合速度有利于聚合物形态的控制，并且通过精确控制聚合过程和聚合物组成，在较高聚合物含量下可获得优异的电光性能。聚合物形态和电光性能受聚合物含量以及丙烯酸酯与环氧树脂之间的质量比影响。通过将丙烯酸酯与环氧树脂的质量比控制为1:1，整合更高密度的散射中心和更低的锚定效应，可在样品中获得最佳的电光性能。随着聚合物含量的增加，增加E6M质量比的策略有利于改善电光性能以减轻聚合物密度。这项工作为液晶单体的逐步聚合提供了见解，并为制备新型液晶调光膜提供了一种新奇的策略。
