New Liquid-Crystalline Elastomers: 1. Synthesis, Structure, and Phase Behavior of a Series of Mesogenic Crosslinking Agents Containing Reactive Bifunctional Groups
摘要:
The synthesis of eight mesogenic crosslinking agents (1c-8c) containing reactive bifunctional groups is described. The chemical structures were characterized by Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectra. The mesomorphism was investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The compounds 1c, 2c, 3c, 5c, 6c, and 8c showed an enantiotropic nematic phase. In addition, 5c exhibited a smectic A (SmA) phase on cooling; 4c exhibited a smectic C (SmC) phase, a SmA phase, and a nematic phase and a monotropic a smectic B (SmB) phase on cooling. 7c revealed an SmA phase and a nematic phase and a monotropic SmC phase on cooling.
由于具有更好的功能性,液晶嵌段共聚物(LCBCP)有望用于开发功能性材料。利用氢化硅烷化过程中炔基和乙烯基之间反应性随温度变化的优势,报告了一系列具有嵌段共聚物模块功能性的LCBCP,它们通过独立和选择性地连接含炔基的偶氮苯部分(LC 1)和Si-H (LC 2)端子连接到设计良好的聚(苯乙烯)-嵌段-聚丁二烯(PS- b - PBs)和聚(4-乙烯基苯基二甲基硅烷)-嵌段-聚丁二烯(PVPDMS- b)中‐PBs)由活性阴离子聚合(LAP)产生。通过模块化功能化的原则,它表明,单官能化的(PVPDMS-摹-LC 1) - b -PB和PS- b - (PB- g ^ -LC 2)不仅保持独立,但也有双向合作贡献-官能化(PVPDMS-克-LC 1) - b - (PB-克-LC 2)的介晶性能和微相分离,这从差示扫描量热法(DSC)和偏振光学形态(POM)可以明显看出,并通过粉末X射线衍