A high-performance liquid crystal polyarylate fiber material and preparation method thereof

Abstract

The present invention provides a high-performance liquid crystal polyarylate fiber material and a preparation method thereof, comprising the steps of preparing a modified material, obtaining the liquid crystal polyarylate fiber material, and preparing a fiber composite film. During these steps, a functional inorganic material is introduced to enhance the performance of the liquid crystal polyarylate fiber. This method is simple, safe, and environmentally friendly. The functional inorganic material is evenly distributed on the liquid crystal polyarylate microfibers and is not easily detached, resulting in high-performance liquid crystal polyarylate fibers, which can be applied more widely.

Description

Technical Field

[0001] The present invention belongs to the technical field of high molecular polymers and relates to a high-performance liquid crystal polyarylate fiber material and a preparation method thereof. Background Art

[0002] With the advancement of miniaturization and high-frequency electronic products, electromagnetic radiation emitted by electronic components during operation is becoming increasingly serious. This not only affects the performance of nearby precision devices but also threatens human health. Traditional metal electromagnetic shielding materials are widely used, but they face challenges such as poor corrosion resistance, high density, and low electromagnetic wave absorption. Polymer materials are gaining increasing attention due to their lightweight, easy processing, and excellent corrosion resistance. However, most polymers are poor conductors. Therefore, incorporating fillers with high electrical and thermal conductivity into the polymer matrix is ​​considered one of the most feasible and effective approaches. Liquid crystal polyarylates (LCPPs) are polymers that can form a liquid crystal state under certain conditions. They exhibit excellent thermal stability, chemical resistance, and superior mechanical properties. These exceptional properties stem from the unique structure of the mesogenic unit within the LCPP molecules, which can induce the ordering of the liquid crystal phase in the melt. Furthermore, MXene is a novel two-dimensional material that offers numerous advantages over other two-dimensional materials, including high specific surface area, superior electrical conductivity, a chemically active surface, and strong electromagnetic wave absorption. However, limited research has focused on using MXene as a filler to enhance the performance of LCPPs.

[0003] High-performance liquid crystal polyarylate fiber materials are made by mechanically shearing liquid crystal polyarylate fibers into micron-sized microfibers, dispersing them in acetic acid, adding an aminocaproic acid solution, and thoroughly mixing them with a MXene solution. The resulting composite film, formed by uniformly mixing MXene and liquid crystal polyarylate, exhibits excellent photothermal conversion performance, high electrical conductivity, and good electromagnetic interference shielding effectiveness. This high-performance liquid crystal polyarylate fiber material has not been reported previously. Summary of the Invention

[0004] The present invention aims to provide a high-performance liquid crystal polyarylate fiber material. Micron-sized liquid crystal polyarylate microfibers are obtained by mechanical shearing and crushing, and then uniformly mixed with MXene in an acetic acid solution, filtered, and hot-pressed into a film with a thickness comparable to that of A4 paper. The composite film has excellent light-to-heat conversion performance, high electrical conductivity, and electromagnetic shielding performance.

[0005] In order to achieve the above object, the present invention provides a preparation method of a high-performance liquid crystal polyarylate fiber material:

[0006] (1) Ti3AlC2 powder was slowly added to a mixed solution containing lithium fluoride and hydrochloric acid while stirring continuously. After etching, the mixture was repeatedly washed with deionized water and centrifuged to obtain MXene.

[0007] (2) placing the liquid crystal polyarylate chopped fibers into a mechanical crusher, adding deionized water, and mechanically shearing and crushing the fibers to obtain a liquid crystal polyarylate microfiber aqueous dispersion, which is then filtered and dried for later use;

[0008] (3) The liquid crystal polyarylate microfibers prepared in step (2) were added to a beaker containing acetic acid, and then uniformly dispersed using a digital high-speed disperser homogenizer. The aminocaproic acid solution was added, and after continuous stirring, the MXene solution was slowly added dropwise. The suspension was filtered to form a film, dried, and hot-pressed.

[0009] Preferably, the mass ratio of the Ti3AlC2 powder to lithium fluoride in step (1) is (0.6-0.7): 1, 1 g of lithium fluoride corresponds to 12-13 mL of 9 mol / mL hydrochloric acid solution, and the mixture is stirred at 200-400 rpm at 30-40 ° C for 24-48 hours. After etching, the mixture is repeatedly washed with deionized water to a pH value of 6.0-7.0, and then centrifuged at 3000-4000 rpm for 20-40 minutes to obtain MXene.

[0010] Preferably, the liquid crystal polyarylate chopped fibers in step (2) have a length of 2 to 4 cm and a diameter of 30 to 40 μm, 10 g of the chopped fibers correspond to 2 to 4 L of deionized water, the mechanical shearing and crushing time is 1 to 2 hours, and the obtained microfiber diameter range is 0.5 to 3 μm. The obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50 to 70° C. and dried for 4 to 6 hours.

[0011] Preferably, 100 mg of the liquid crystal polyarylate microfibers described in step (3) is added to a beaker containing 15 to 30 mL of acetic acid, the speed of the digital high-speed disperser homogenizer is 4 to 5 kr / min, 2 to 3 mL of 20 mg / mL aminocaproic acid solution is added, and the mixture is stirred at a speed of 200 to 400 rpm for 24 to 48 hours. During the stirring process, 10 to 15 mg / mL of MXene solution is slowly added dropwise, and the suspension is filtered to form a film. The vacuum oven drying temperature is 40 to 50 ° C, the drying time is 3 to 4 hours, the hot pressing temperature is 25 ° C, 220 ° C, 240 ° C, 260 ° C and 280 ° C, and the hot pressing pressure is 5 to 10 MPa.

[0012] Compared with the prior art, the present invention has the following positive beneficial effects:

[0013] (1) The present invention provides a method for preparing a high-performance liquid crystal polyarylate fiber material. The preparation process is simple. Liquid crystal polyarylate fibers are mechanically sheared and crushed to obtain liquid crystal polyarylate microfibers. No chemical reagents are added to the process, and only deionized water is used. The processing is safe and environmentally friendly. The mixing process of the liquid crystal polyarylate microfibers and MXene does not require the participation of toxic reagents or solvents, and does not emit toxic gases or liquids. Only acetic acid is used as the solvent, and the acetic acid after filtration can be reused, which is environmentally friendly.

[0014] (2) The present invention provides a method for preparing a high-performance liquid crystal polyarylate fiber material. The uniform mixing of MXene and liquid crystal polyarylate microfibers is achieved thanks to the action of aminocaproic acid. After continuous stirring, the MXene flakes are evenly distributed on the surface of the liquid crystal polyarylate microfibers, so that the composite film has good photothermal conversion performance, electrical conductivity and electromagnetic shielding effectiveness.

[0015] (3) The present invention provides a method for preparing a high-performance liquid crystal polyarylate fiber material. The composite film formed by MXene and liquid crystal polyarylate microfibers has a thickness equivalent to that of A4 paper after hot pressing. Its internal structure is more compact and has better hydrophobicity, which can prevent the composite film from reducing its shielding performance due to water absorption, thereby forming a more excellent environmental stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 (a) is a macroscopic photograph of liquid crystal polyarylate microfibers. Figure 1 (b) Macroscopic photograph of liquid crystal polyarylate microfibers dispersed in deionized water and acetic acid solution.

[0017] Figure 2 (a) is the SEM morphology of liquid crystal polyarylate fiber. Figure 2 (b) is the SEM morphology of liquid crystal polyarylate microfibers.

[0018] Figure 3 (a) is a macroscopic photograph of pure liquid crystal polyarylate microfiber membrane. Figure 3 (b) is a macroscopic photograph of the MXene / liquid crystal polyarylate microfiber composite membrane. Figure 3 (c) Macroscopic photograph of pure liquid crystal polyarylate microfiber membrane after hot pressing at 25°C and 10 MPa. Figure 3 (d) Macroscopic photograph of the MXene / liquid crystal polyarylate microfiber composite film after hot pressing at 260°C and 10 MPa.

[0019] Figure 4 (a) is the EMI SE of MXene / liquid crystal polyarylate microfiber composite membrane, Figure 4 (b) Shielding efficiency of MXene / liquid crystal polyarylate microfiber composite film.

[0020] Figure 5The electrical conductivity of the MXene / liquid crystal polyarylate microfiber composite membrane after hot pressing at 25°C and 10 MPa.

[0021] Figure 6 The electrical conductivity of the MXene / liquid crystal polyarylate microfiber composite membrane after hot pressing at 260°C and 10 MPa.

[0022] Comparative Example 1

[0023] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0024] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0025] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of deionized water. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 1.8 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 25°C and a pressure of 10 MPa.

[0026] Comparative Example 2

[0027] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0028] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0029] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of deionized water. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 4.3 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 25°C and a pressure of 10 MPa.

[0030] Comparative Example 3

[0031] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0032] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0033] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of deionized water. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 10 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 25°C and a pressure of 10 MPa.

[0034] Example 1

[0035] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0036] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0037] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 1.8 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 25°C and a pressure of 10 MPa.

[0038] Example 2

[0039] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0040] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0041] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 4.3 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 25°C and a pressure of 10 MPa.

[0042] Example 3

[0043] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0044] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0045] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 10 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 25°C and a pressure of 10 MPa.

[0046] Example 4

[0047] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0048] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0049] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 1.8 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 240°C and a pressure of 10 MPa.

[0050] Example 5

[0051] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0052] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0053] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 4.3 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 240°C and a pressure of 10 MPa.

[0054] Example 6

[0055] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0056] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0057] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 10 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 240°C and a pressure of 10 MPa.

[0058] Example 7

[0059] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0060] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0061] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 1.8 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 260°C and a pressure of 10 MPa.

[0062] Example 8

[0063] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0064] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0065] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 4.3 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 260°C and a pressure of 10 MPa.

[0066] Example 9

[0067] 0.3 g of Ti3AlC2 powder was slowly added to a mixed solution containing 0.48 g of lithium fluoride and 6 mL of 9 mol / mL hydrochloric acid, and stirred at 300 rpm at 35 ° C for 36 hours. After etching, it was repeatedly washed with deionized water to pH = 6.0-7.0, shaken by the robotic arm for 1 hour, ultrasonicated for 15 minutes, and then centrifuged at 3500 rpm for 30 minutes to obtain a MXene solution.

[0068] Use a cutter to cut the liquid crystal polyarylate fiber into 2 cm short fibers with a diameter of 30-40 μm, put them into a mechanical crusher, add 3 L of deionized water, and mechanically shear and crush for 1 hour. After physical disassembly, the obtained liquid crystal polyarylate microfiber aqueous dispersion is filtered and placed in a vacuum oven at 50°C to dry for 5 hours.

[0069] 100 mg of liquid crystal polyarylate microfibers were added to a beaker containing 20 mL of acetic acid. The liquid crystal polyarylate microfibers were broken up using a digital high-speed disperser homogenizer at a speed of 5 kr / min. Then 2.5 mL of 20 mg / mL aminocaproic acid solution was added and stirred at 300 rpm for 48 hours. During the stirring process, 10 mL of 10 mg / mL MXene solution was slowly added dropwise. The suspension was filtered to form a membrane and placed in a vacuum oven at 50°C for 4 hours. The MXene / liquid crystal polyarylate microfiber composite membrane was pressed into a thickness equivalent to A4 paper using a flat vulcanizer at 260°C and a pressure of 10 MPa.

[0070] Therefore, compared with the control example, replacing deionized water with acetic acid solution as the solvent effectively solved the uniformity problem of the MXene / liquid crystal polyarylate composite film. Because water is used as a solvent, there is no interaction force between MXene and liquid crystal polyarylate microfibers. The size of MXene is 3 to 5 μm. During the filtration process, the MXene flakes will be filtered off first, which will greatly affect the performance of the composite film. Using acetic acid as a solvent, under acidic conditions, coupled with the effect of aminocaproic acid, MXene can be evenly dispersed on the surface of liquid crystal polyarylate microfibers. After filtration and hot pressing, the formed MXene / liquid crystal polyarylate composite film has excellent photothermal conversion performance, high conductivity and good electromagnetic interference shielding effectiveness.

[0071] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

[0072] Table 1 Parameters and experimental results of control example and each example

[0073]

Claims

1. A method for preparing a high-performance liquid crystal polyarylate fiber material, characterized in that: The steps are as follows: (1) Ti3AlC2 powder was slowly added to a mixed solution containing lithium fluoride and hydrochloric acid, and stirred continuously. After etching, the mixture was repeatedly washed with deionized water and centrifuged to obtain MXene. (2) Putting the liquid crystal polyarylate chopped fibers into a mechanical crusher, pouring deionized water into it, and mechanically shearing and crushing it to obtain a liquid crystal polyarylate microfiber aqueous dispersion, which is then filtered and dried for later use; (3) The liquid crystal polyarylate microfibers prepared in step (2) are added to a beaker containing acetic acid, and then uniformly dispersed using a digital high-speed disperser homogenizer, and aminocaproic acid solution is added. After continuous stirring, the MXene solution is slowly added dropwise, and the suspension is filtered to form a membrane, dried, and hot-pressed.

2. The method for preparing a high-performance liquid crystal polyarylate fiber material according to claim 1, characterized in that: The mass ratio of Ti3AlC2 powder to lithium fluoride in step (1) is (0.6~0.7): 1, 1g of lithium fluoride corresponds to 12~13mL of 9mol / mL hydrochloric acid solution, stirred at 200-400rpm at 30~40℃ for 24~48h. After etching, it is repeatedly washed with deionized water to a pH value of 6.0~7.0, and then centrifuged at 3000~4000rpm for 20~40min to obtain MXene.

3. The method for preparing a high-performance liquid crystal polyarylate fiber material according to claim 1, characterized in that: The liquid crystal polyarylate chopped fibers described in step (2) have a length of 2-4 cm and a diameter of 30-40 μm. 10 g of chopped fibers correspond to 2-4 L of deionized water. The mechanical shearing and crushing time is 1 h-2 h, and the obtained microfibers have a diameter range of 0.5-3 μm.

4. The method for preparing a high-performance liquid crystal polyarylate fiber material according to claim 1, characterized in that: 100 mg of liquid crystal polyarylate microfibers described in step (3) are added to a beaker containing 15-30 mL of acetic acid. The speed of the digital high-speed dispersing homogenizer is 4-5 kr / min. 2-3 mL of 20 mg / mL aminocaproic acid solution is added and stirred at a speed of 200-400 rpm for 24-48 h. During the stirring process, 10-15 mg / mL of MXene solution is slowly added dropwise. The suspension is filtered to form a film. The vacuum oven drying temperature is 40-50 ° C, the drying time is 3-4 h, the hot pressing temperature is 25 ° C, 220 ° C, 240 ° C, 260 ° C and 280 ° C, and the hot pressing pressure is 5-10 MPa.

5. A high performance liquid crystal polyarylate fiber, characterized in that : The high-performance liquid crystal polyarylate fiber is prepared by the preparation method according to any one of claims 1 to 4.

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