MESOMORPHISM IN SEGMENTED-CHAIN POLYMERS CONTAINING FLEXIBLE SUBSTITUENTS IN THE RIGID MOIETY
MESOMORPHISM IN SEGMENTED-CHAIN POLYMERS CONTAINING FLEXIBLE SUBSTITUENTS IN THE RIGID MOIETY
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DOI：
10.1021/ma00122a014
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发表时间：
1995-08-28
期刊：
影响因子：
5.5
通讯作者：
IANNELLI, P
中科院分区：
文献类型：
--
作者：
CARUSO, U;PRAGLIOLA, S;IANNELLI, P
报道了一组具有中等链柔度和高柔性侧取代基的聚合物的合成及其相行为。分子式为(-p- c6h4 - ooc -p- c6h3 (R)- coo -p- c6h4 -O(CH2)(n)O-)(x), R = -O(CH2)(m-1)CH3 (m = 5-8), n = 2,4。横向取代基的存在，加上一些链的柔韧性，导致相对较低的熔融温度（低于类似的190摄氏度，退火样品），允许向列液晶行为以热向性，对映性的方式显示。室温退火纤维样品的x射线衍射数据表明，沿纤维轴的结构周期性基本上对应于其最延伸构象的单体单元的长度。这同样适用于未退火的纤维。;然而，在这种情况下，沿纤维轴和跨纤维轴的链状排列的规律性被极大地扰乱，因此固体状态最好被归类为中间相。
The synthesis and the phase behavior of a set of polymers characterized by having moderate chain flexibility and highly flexible lateral substituents are reported. The polymers have general formula (-p-C6H4-OOC-p-C6H3(R)-COO-p-C6H4-O(CH2)(n)O-)(x) with R = -O(CH2)(m-1)CH3 (m = 5-8) and n = 2, 4. The presence of the lateral substituents, together with some chain flexibility, leads to comparatively low melting temperatures (lower than similar to 190 degrees C, for annealed samples) allowing a nematic liquid-crystalline behavior to show up in a thermotropic, enantiotropic way. X-ray diffraction data collected for annealed fibrous samples at room temperature indicate that the structural periodicity along the fiber axis substantially corresponds to the length of the monomer unit in its most extended conformation. The same holds for fibers not annealed. In;this case, however, the regularity of the chain packing both along and across the fiber axis is drastically disturbed such that the solid state should better be classified as a mesophase.