Morphology of shear-induced textures in a thermotropic liquid crystal copolyester—relationship between banded and tight textures
Morphology of shear-induced textures in a thermotropic liquid crystal copolyester—relationship between banded and tight textures
复制标题
热致液晶共聚酯中剪切诱导织构的形态——带状织构和致密织构之间的关系
DOI：
10.1016/0032-3861(90)90277-6
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发表时间：
1990
期刊：
影响因子：
4.6
通讯作者：
A. Windle
中科院分区：
文献类型：
--
作者：
S. Bedford;A. Windle
热致液晶聚合物的属性之一是它们在熔融状态下容易流动。流动过程强烈影响所得的微观结构，因此显微镜可以提供理解这些材料特性的关键。所谓的带状和紧密的光学织构是两种最常见的流动诱导微观结构，发生在模塑制品和挤出纤维中。本文讨论的形态与这些纹理观察到的剪切膜的随机取向。扫描电子显微镜和X射线衍射表明，尽管它们的光学外观非常不同，但它们的形态是非常密切相关的。在这两种情况下，观察到良好的分子取向相对于层平行于剪切平面内的分子采用蜿蜒的轨迹。在带状织构中，分子在层内遵循更有序的路径，并且存在更高程度的层间配准。
One of the attributes of thermotropic liquid crystal polymers is the ease with which they flow in the molten state. The flow processes strongly affect the resulting microstructure so that microscopy can provide a key in understanding the properties of these materials. The so-called banded and tight optical textures are two of the most commonly encountered flow-induced microstructures, occurring in mouldings and extruded fibres. This paper discusses the morphology associated with these textures as observed in sheared films of a random copolyester. Scanning electron microscopy and X-ray diffraction indicated that, despite their very different optical appearance, their morphologies are quite closely related. In both cases good molecular orientation is observed with respect to layers parallel to the shear plane within which the molecules adopt sinuous trajectories. In the banded texture the molecules follow a more ordered path within the layers and there is a higher degree of inter-layer register.