Lee Won Jun, Kwac Lee Ku, Kim Hong Gun, Chang Jin-Hae
Department of Polymer Science and Engineering, Kumoh National Institute of Technology, Gumi, 39177, Korea.
Graduate School of Carbon Convergence Engineering, Jeonju University, Jeonju, 55069, Korea.
Sci Rep. 2021 Jun 2;11(1):11654. doi: 10.1038/s41598-021-91212-4.
Thermotropic liquid crystal copolyester (TLCP) was synthesized using a melt polymerization method, with a molar ratio composition of 2,5-diethoxy terephthalic acid (ETA), hydroquinone (HQ), and p-hydroxybenzoic acid (HBA) of 1:1:3. TLCP exhibited nematic liquid crystalline mesophase and maintained nematic textures under all heat treatment conditions applied. The synthesized TLCP was processed into fibers using a capillary rheometer. The liquid crystalline mesophase, thermo-mechanical properties, and morphology of TLCP fibers obtained under various heat treatment conditions were investigated. The thermo-mechanical properties of the heat-treated fibers were improved compared to those of the as-spun fibers. The best results were obtained for TLCP fibers annealed at 230 °C for 9 h. The heat-treated fibers showed a well-developed microfiber morphology compared to the as-spun fibers. In the spun fibers, a skin-core morphology was observed regardless of the heat treatment conditions, and a well-developed fiber morphology better than the core area was observed in the skin area. The diameter of the fiber heat-treated at 230 °C for 9 h was approximately 60-110 nm.
采用熔融聚合法合成了热致液晶共聚酯（TLCP），其2,5-二乙氧基对苯二甲酸（ETA）、对苯二酚（HQ）和对羟基苯甲酸（HBA）的摩尔比组成为1:1:3。TLCP呈现向列型液晶中间相，并且在所施加的所有热处理条件下均保持向列织构。使用毛细管流变仪将合成的TLCP加工成纤维。研究了在各种热处理条件下获得的TLCP纤维的液晶中间相、热机械性能和形态。与初生纤维相比，热处理纤维的热机械性能得到了改善。对于在230℃下退火9小时的TLCP纤维，获得了最佳结果。与初生纤维相比，热处理纤维呈现出发育良好的微纤维形态。在纺丝纤维中，无论热处理条件如何，均观察到皮芯形态，并且在皮层区域观察到比芯部区域更好的发育良好的纤维形态。在230℃下热处理9小时的纤维直径约为60 - 110纳米。
