【摘要】 针对热致液晶聚芳酯(TLCPAR)初生纤维结构不稳定、强度不高的问题,对其进行热处理以提高纤维分子质量,进而提高纤维的强度。将处于松弛状态的TLCPAR纤维置于热处理箱中,在不同的热处理温度和时间下进行热处理。借助广角X射线衍射仪、纱线强伸度仪测试与分析纤维的结晶度、晶粒尺寸、晶区取向以及纤维力学性能的变化。结果表明:热处理后TLCPAR纤维的(110)晶面和(211)晶面的晶粒尺寸显著增加,230℃热处理48 h后纤维的结晶度增加了37.1%,取向度仅下降2%,说明TLCPAR纤维中大分子链的堆砌更有序、更紧密;热处理后结构变化使TLCPAR纤维断裂强度增加了86.8%,弹性模量增加了20.9%。更多还原

【Abstract】 In view of the unstable structure and low strength of thermotropic liquid crystalline polyarylate(TLCPAR) as-spun fiber, the heat treatment was carried out to increase the molecular weight and therefore improve the strength of the fiber. The TLCPAR as-spun fiber with relaxed state was treated under the conditions of different heat treatment temperatures and time in nitrogen gas flow. The wide angle X-ray diffraction was adopted to analyze the crystallinity, crystalline size and orientation and the mechanical properties were tested by yarn strength tester. The results show that after heat treatment, the crystalline size of the(110) and(211) planes of the TLCPAR fiber has a significant increase. After being subjected to the heat treatment of 230 ℃ for 48 h, the crystallinity of the fiber increases by 37.1%, and the crystalline orientation decreases only 2%. It is shown that the molecular chains are stacked more orderly and closely after heat treatment. The change in structure of TLCPAR fiber results in an increase of 86.8% in strength and 20.9% in elastic modulus.更多还原