Control of Cross-Linking Polymerization Kinetics and Polymer Aggregated Structure in Polymer-Stabilized Liquid Crystalline Blue Phases
Control of Cross-Linking Polymerization Kinetics and Polymer Aggregated Structure in Polymer-Stabilized Liquid Crystalline Blue Phases
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DOI：
10.1021/ma802464w
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发表时间：
2009-03-24
期刊：
影响因子：
5.5
通讯作者：
Kikuchi, Hirotsugu
中科院分区：
文献类型：
--
作者：
Iwata, Takashi;Suzuki, Ken;Kikuchi, Hirotsugu
基于动态力学分析，研究了丙烯酸酯和甲基丙烯酸酯单体在液晶蓝相中的交联共聚反应动力学，制备了聚合物稳定的蓝色相。虽然甲基丙烯酸酯单体的聚合速率一般远低于丙烯酸酯单体的聚合速率，但我们发现，当丙烯酸酯和甲基丙烯酸酯单体通过交联剂进行共聚时，甲基丙烯酸酯交联剂促进了交联共聚，而丙烯酸酯交联剂抑制了交联共聚。单官能团单体/双官能团单体的共聚反应速率大小顺序为：单丙烯酸酯(Ma)/二甲基丙烯酸酯(DMA)>MA/双丙烯酸酯(Da)>单甲基丙烯酸酯(MMA)/DMA>MMA/da。用同步辐射小角X射线散射法研究了聚合物稳定的蓝相中聚合物网络的聚集结构，发现了与蓝相的错位晶格相对应的规则的聚合物结构，表明聚合物优先偏聚在错核中。聚合物网络的规整度与共聚速率的大小顺序相反。在聚合物稳定的蓝色相中，聚合动力学、机械弹性常数和聚合物聚集结构之间具有很好的相关性，这为控制聚合物稳定的蓝色相的结构和性能提供了新的策略。
Kinetics of cross-linking copolymerization of acrylate- and methacrylate-monomers in a liquid crystal blue phase to prepare the polymer-stabilized blue phase were investigated based on dynamic mechanical analysis. Although the polymerization rate of methacrylate-monomers is generally much lower than that of acrylate-ones, we found that a methacrylate cross-linker enhanced the cross-linking copolymerization and an acrylate one suppressed it when acrylate- and methacrylate-monomers were copolymerized with cross-linking. The order of copolymerization rate of monofunctional monomer/difunctional one was monoacrylate (mA)/dimethacrylate (dMA), mA/diacrylate (dA), monomethacrylate (mMA)/dMA, and mMA/dA. The synchrotron small-angle X-ray scattering measurements were carried out to evaluate the aggregated structure of polymer networks in the polymer-stabilized blue phase and found the regular polymer structure corresponding to the disclination lattice of the blue phase, indicating that the polymers were segregated preferentially in the disclination cores. The degree of the regularity of polymer networks was opposite order of copolymerization rate. We obtained a good correlation among the polymerization kinetics, the mechanical elastic constant and the polymer aggregation structure in the polymer-stabilized blue phases, leading to a novel strategy to control the structure and the performance of the polymer-stabilized blue phases.