Zhang Bao-Yan, Meng Fan-Bao, Li Qian-Yue, Tian Mei
The Research Centre for Molecular Science and Engineering, Northeastern University, Shenyang, 110004, People's Republic of China.
Langmuir. 2007 May 22;23(11):6385-90. doi: 10.1021/la070179s. Epub 2007 Apr 24.
A series of liquid-crystalline polysiloxanes synthesized by cholest-5-en-3-ol (3beta)-10-undecenoate and 4'-octanoyloxy-biphenyl-4-yl 4-allyloxy-3-sulfo-benzoate were prepared in a one-step reaction with sulfonic acid group contents ranging between 0 and 2.73 wt %. All the polymers displayed smectic mesophases with a large temperature range for the mesophases. With an increase of sulfonic acid containing mesogens in the polymers, the temperature of the glass transition did not change greatly, while the temperature of the clear point decreased. The hydrogen-bonding mesogen aggregates in the domains disturb the liquid-crystalline molecular mobility and orientation, leading to a decrease in temperature from the mesophase to the isotropic transition. Unlike the polymers containing lower sulfonic acid mesogens, some polymers showed a dendritic texture of the SmB* phase, indicating that the sulfonic mesogens enhanced the rigid moieties of the supermolecular structure of the liquid-crystalline phases. All the polymers displayed sharp and strong peaks at low angles around 2theta approximately 2.6 degrees and broad peaks at wide angles around 2theta approximately 17 degrees in X-ray measurements. The intensity of the strong peak at low angles in the X-ray profiles decreased with an increase of sulfonic acid mesogens in the polymer systems.
通过胆甾 - 5 - 烯 - 3 - 醇（3β）-10 - 十一碳烯酸酯和4'-辛酰氧基 - 联苯 - 4 - 基4 - 烯丙氧基 - 3 - 磺酸苯甲酸酯合成了一系列液晶聚硅氧烷，它们是在一步反应中制备的，磺酸基团含量在0至2.73 wt％之间。所有聚合物均呈现近晶相，且中间相温度范围较大。随着聚合物中含磺酸介晶基团的增加，玻璃化转变温度变化不大，而清亮点温度降低。畴内的氢键介晶聚集体扰乱了液晶分子的迁移率和取向，导致从中间相到各向同性转变的温度降低。与含较低磺酸介晶基团的聚合物不同，一些聚合物呈现出SmB*相的树枝状织构，这表明磺酸介晶增强了液晶相超分子结构的刚性部分。在X射线测量中，所有聚合物在约2θ为2.6°左右的低角度处显示出尖锐且强烈的峰，在约2θ为17°左右的宽角度处显示出宽峰。随着聚合物体系中磺酸介晶基团的增加，X射线图谱中低角度处强峰的强度降低。
