Phase transformations of liquid crystalline side-chain oligomers
Phase transformations of liquid crystalline side-chain oligomers
复制标题
液晶侧链低聚物的相变
DOI：
10.1021/ma00134a053
复制
发表时间：
1984
期刊：
影响因子：
5.5
通讯作者：
H. Finkelmann
中科院分区：
文献类型：
--
作者：
H. Stevens;G. Rehage;H. Finkelmann
合成了液晶（lc）低聚物，以便更详细地了解液晶侧链聚合物从单体到聚合物的相行为变化。低聚物的相变温度被确定为聚合度r的函数。对于 3< r< 10，所有系统都观察到相变温度急剧增加。随着r的增加，向列相的稳定范围比近晶相的稳定范围扩大。类似于低摩尔质量 l 的压力-温度行为。 c’s，这种效应可归因于随着聚合程度的增加，低聚物介晶侧链的堆积逐渐密集。从宏观上可以看出，在相变温度下，比容随 r 减小。
Liquid crystalline (lc) oligomers were synthesized in order to obtain a more detailed un-derstanding of the change of thephase behaviorfrom the monomer to the polymer of lc side-chain polymers. The phase transformation temperatures of oligomers were determined as a function of the degree of polymerization r. For 3< r< 10 a steep increase in phase transformation temperature is observed for all systems. With growing r the stability range of the nematic phase is more extended than the stability range of the smectic phase. In analogy to the pressure-temperature behavior of low molar mass l. c’s, this effect can be attributed to progressively denser packing of the mesogenic side chains of the oligomers with growing degree of po-lymerization. This is macroscopically seen in a decrease of specific volumeat the phase transformation temperature with r.