Park Sanghyeon, Na Yeji, Kim A Young, Kwac Lee Ku, Kim Hong Gun, Chang Jin-Hae
Graduate School of Carbon Convergence Engineering, Jeonju University, Jeonju, 55069, South Korea.
Institute of Carbon Technology, Jeonju University, Jeonju, 55069, South Korea.
Sci Rep. 2022 Jul 30;12(1):13100. doi: 10.1038/s41598-022-17431-5.
A series of thermotropic liquid crystal copolyesters (Co-TLCPs) was prepared by melt polymerization using 2,5-diethoxyterephthalic acid (DTA), 2,7-dihydroxynaphthalene (DHN), and p-hydroxybenzoic acid (HBA) monomers, where the HBA content was varied (0-5 mol). At 3 mol HBA, the Co-TLCPs formed nematic mesophases, while below this concentration, the liquid crystalline phase did not appear. The Co-TLCP sample with 3 mol HBA was subjected to melt spinning and heat-treated under various conditions (temperature and time) to investigate their effect on the thermo-mechanical properties and degree of crystallinity. The objective was to determine the critical heat treatment condition that can maximize the properties of the spun Co-TLCP fibers. The microstructure of the heat-treated fiber was investigated using scanning electron microscopy, and the optimal annealing conditions were confirmed based on the morphology of the fiber, which exhibited a skin-core structure owing to the varying heat and pressure conditions applied during spinning.
通过熔融聚合，使用2,5 - 二乙氧基对苯二甲酸（DTA）、2,7 - 二羟基萘（DHN）和对羟基苯甲酸（HBA）单体制备了一系列热致液晶共聚酯（Co - TLCPs），其中HBA的含量有所变化（0 - 5摩尔）。当HBA含量为3摩尔时，Co - TLCPs形成向列型中间相，而低于此浓度时，液晶相未出现。对含有3摩尔HBA的Co - TLCP样品进行熔融纺丝，并在各种条件（温度和时间）下进行热处理，以研究其对热机械性能和结晶度的影响。目的是确定能够使纺制的Co - TLCP纤维性能最大化的临界热处理条件。使用扫描电子显微镜研究了热处理纤维的微观结构，并根据纤维的形态确认了最佳退火条件，由于纺丝过程中施加的热和压力条件不同，纤维呈现出皮芯结构。
