The Contribution of Oligomerization Reaction Chemistry to the Thermomechanical Properties of Surface-Aligned Liquid Crystalline Elastomers
The Contribution of Oligomerization Reaction Chemistry to the Thermomechanical Properties of Surface-Aligned Liquid Crystalline Elastomers
复制标题
低聚反应化学对表面取向液晶弹性体热机械性能的贡献
DOI：
10.1021/acs.macromol.2c02371
复制
发表时间：
2023
期刊：
影响因子：
5.5
通讯作者：
White, Timothy J.
中科院分区：
文献类型：
--
作者：
Hebner, Tayler S.;McCracken, Joselle M.;Bowman, Christopher N.;White, Timothy J.
液晶弹性体（LCE）是刺激响应性材料，当宏观上对齐时，其经历大的定向变形，该变形通过聚合物网络内的秩序的破坏而放大。最近，表面强制排列已被用来制备LCE的空间变化的方向，使复杂的3-D形状变换的实现。表面强制配向是有利的，因为它允许LCE内的双折射指向矢的高分辨率、非线性图案化。当使用表面配向来增强LCE内的取向时，通常使用多个两步反应方案，主要是氮杂-迈克尔低聚或硫醇-迈克尔低聚，其中每个加成反应随后是残余丙烯酸酯封端的低聚物的光聚合。在此，通过每种聚合技术用不同的胺或硫醇浓度制备LCE。LCE的机械性能，热机械响应，反应动力学和对齐进行了表征和评估。该检查强调了在用于形成低聚物的反应中交联之间的分子量在确定LCE的刺激响应的幅度中的重要性。
Liquid crystalline elastomers (LCEs) are stimulus-responsive materials that, when macroscopically aligned, undergo large, directional deformation amplified by the disruption of order within a polymer network. Recently, surface-enforced alignment has been used to prepare LCEs with spatial variation in the director orientation that enables the realization of complex 3-D shape transformation. Surface-enforced alignment is advantageous because it allows for high-resolution, nonlinear patterning of the nematic director within an LCE. When using surface alignment to enforce orientation within LCEs, multiple two-step reaction schemes have been commonly used, primarily aza-Michael oligomerization or thiol-Michael oligomerization with each addition reaction followed by photopolymerization of the residual acrylate-terminated oligomers. Here, LCEs were prepared by each polymerization technique with varied amine or thiol concentrations. The mechanical properties, thermomechanical response, reaction kinetics, and alignment were characterized and assessed for LCEs. This examination emphasizes the importance of the molecular weight between crosslinks over the reaction used to form the oligomer in determining the magnitude of the stimulus response of LCEs.
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影响因子：
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作者：
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通讯作者：
White, Timothy J.