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首页> 外文期刊>Journal of Applied Polymer Science >Synthesis and melt spinning of fully aromatic thermotropic liquid crystalline copolyesters containing m-hydroxybenzoic acid units
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Synthesis and melt spinning of fully aromatic thermotropic liquid crystalline copolyesters containing m-hydroxybenzoic acid units

机译：含间羟基苯甲酸单元的全芳族热致液晶共聚酯的合成和熔融纺丝

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摘要

Fibers of fully aromatic thermotropic copolyesters based on p-acetoxybenzoic acid (p-ABA), hydroquinone diacetate (HQDA), terephthalic acid (TPA), and m-acetoxybenzoic acid (m-ABA) were prepared by a high-temperature melt-spinning technique. Two types of the copolyesters were prepared by a high-temperature melt polycondensation reaction using 33 mol % of kink (m-ABA) and 67 mol % linear monomer units (p-ABA, TPA, HQDA), and characterized by differential scanning calorimetry (DSC), polarized optical microscopy, wide-angle X-ray diffraction (WAXD), and intrinsic viscosity measurements. The mechanical properties and the morphology of the fibers were also determined by tensile tester, WAXD, and scanning electron microscopy (SEM). The copolyesters exhibited phase-separated nematic liquid crystalline morphology within a broad temperature range in an isotropic matrix. DSC analysis of the copolyesters revealed broad endotherms associated with the nematic phases. The melting and spinning temperatures were in a processable region. Fibers exhibit well-developed fibrillar structure parallel to the fiber axis. The highly oriented morphology of the fibrils is slightly dependent on the type of the linear monomer. The strength and modulus values determined for the fibers that contain equal molar composition of the linear p-ABA, HQDA/TPA units are comparable to other reported rigid systems containing fully aromatic species. (C) 2002 Wiley Periodicals, Inc. [References: 30]
机译：通过高温熔融纺丝制备基于对乙酰氧基苯甲酸（p-ABA），对苯二酚氢二乙酸酯（HQDA），对苯二甲酸（TPA）和间乙酰氧基苯甲酸（m-ABA）的全芳族热致共聚酯纤维。技术。使用33 mol％的扭结（m-ABA）和67 mol％的线性单体单元（p-ABA，TPA，HQDA）通过高温熔融缩聚反应制备两种共聚酯，并通过差示扫描量热法（ DSC），偏振光学显微镜，广角X射线衍射（WAXD）和特性粘度测量。纤维的机械性能和形态也通过拉伸测试仪，WAXD和扫描电子显微镜（SEM）确定。共聚酯在各向同性基体中的宽温度范围内显示出相分离的向列型液晶形态。对共聚酯的DSC分析显示与向列相相关的宽的吸热。熔融和纺丝温度处于可加工区域。纤维具有平行于纤维轴的发达的原纤维结构。原纤维的高度取向形态在某种程度上取决于线性单体的类型。对于包含线性摩尔比相同的线性p-ABA，HQDA / TPA单元的纤维确定的强度和模量值可与其他报道的包含完全芳族物质的刚性系统相媲美。 （C）2002 Wiley Periodicals，Inc. [参考：30]

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