Polyether-ether-ketone aerogel fiber and preparation method thereof

Abstract

The invention relates to a polyether-ether-ketone aerogel fiber and a preparation method thereof, and belongs to the technical field of aerogel fibers. The preparation method of the polyether-ether-ketone aerogel fiber comprises the following steps: firstly, preparing soluble polyether-ether-ketone-1, 3-dithiolane from a crystalline polyether-ether-ketone material, then dissolving the soluble polyether-ether-ketone-1, 3-dithiolane and polyvinylpyrrolidone in a polar solvent, stirring to obtain a spinning solution, and finally, preparing the polyether-ether-ketone aerogel fiber. Performing vacuum defoaming on the spinning solution, extruding the spinning solution into a coagulating bath, and finally performing solvent replacement and vacuum freeze drying to obtain the polyether-ether-ketone aerogel fiber. The preparation method is simple in process and continuous in subsequent process, and is expected to realize large-scale production; the prepared aerogel fiber has a typical three-dimensional network structure, relatively low linear density, relatively high strength, good toughness and good spinnability, and the porous structure of the aerogel fiber provides possibility for subsequent filling or adsorption of a phase change material so as to be applied to the thermal insulation fields of textile, special clothing and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of aerogel fibers, and in particular relates to polyetheretherketone aerogel fibers and a preparation method thereof. Background Art

[0002] Aerogel refers to a nanoscale porous solid material formed by using a sol-gel method and a certain drying method to replace the liquid phase in the gel with gas. It has the advantages of low density, high porosity, and large specific surface area. Therefore, it is widely used in thermal insulation, catalytic loading, adsorption and filtration.

[0003] Aerogel fibers not only have the excellent properties of aerogels, but also have the flexibility and good mechanical properties of fibers. Existing aerogel fibers are mostly aramid aerogel fibers, polyimide aerogel fibers, cellulose aerogel fibers and various inorganic aerogel fibers, but the mechanical properties of such aerogel fibers are still at a relatively weak level. The improvement of the mechanical properties of aerogel fibers requires subsequent processing and modification, and the complex preparation process also makes the production of aerogel fibers face huge challenges.

[0004] For example, patent CN116905120A discloses a method for preparing a polyimide composite aerogel fiber, which adds a hydrolyzed silica aerogel precursor solution to a polyamic acid salt solution to prepare a composite spinning solution, and then performs solvent replacement and freeze drying in sequence after wet spinning to obtain the polyimide aerogel fiber. In this patent, the chemical imidization of polyamic acid is directly carried out in a coagulation bath, so that the reaction conditions are mild, the reaction process is controllable, and it is suitable for large-scale production.

[0005] Patent CN115073803B discloses a method for preparing high-toughness aramid aerogel fibers. In this method, the aerogel fibers are not treated by traditional freeze-drying or supercritical drying. Instead, aerogel fibers with high porosity, nanoscale pore size and extremely high fracture toughness are prepared by drying at normal pressure, which not only improves production efficiency but also reduces production costs.

[0006] Patent CN117127281A discloses a method for preparing bacterial cellulose / polyurethane composite aerogel fibers. The introduction of thermoplastic polyurethane in the above preparation method protects the aerogel skeleton to a certain extent and effectively enhances the mechanical strength of the aerogel fibers. The three-dimensional network skeleton and porous structure of the composite aerogel fibers make the aerogel fibers have excellent mechanical properties and good thermal insulation properties.

[0007] Polyaryletherketone materials are widely used in various fields due to their excellent mechanical properties, temperature resistance, acid and alkali resistance, etc. However, the solvent resistance and high processing temperature of polyaryletherketone materials have brought many difficulties to the preparation and production of polyaryletherketone aerogel fibers. Summary of the invention

[0008] In view of this, the object of the present invention is to provide a polyetheretherketone aerogel fiber and a preparation method thereof, wherein the polyetheretherketone aerogel fiber not only has the advantages of low density and high porosity of aerogel, but also has the flexibility and weavability of fiber.

[0009] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are as follows.

[0010] In a first aspect, the present invention provides a method for preparing polyetheretherketone aerogel fiber, comprising the following steps:

[0011] (1) dissolving soluble polyetheretherketone-1,3-dithiolane and polyvinylpyrrolidone in a polar solvent and dispersing them uniformly to obtain a spinning solution;

[0012] (2) after degassing the spinning solution, extruding and spinning into a coagulation bath, and collecting by winding to obtain polyetheretherketone-1,3-dithiolane wet gel fiber;

[0013] (3) placing the polyetheretherketone-1,3-dithiolane wet gel fiber in a displacement bath for several solvent displacements, and freezing the fiber to obtain polyetheretherketone-1,3-dithiolane fiber;

[0014] (4) Drying the polyetheretherketone-1,3-dithiolane fiber to obtain polyetheretherketone aerogel fiber.

[0015] Preferably, in step (1), the preparation method of the soluble polyetheretherketone-1,3-dithiolane is: under the protection of an inert atmosphere, dissolving the crystalline polyetheretherketone in a solvent to which an auxiliary agent is added, then adding boron trifluoride etherate and 1,2-ethanedithiol, reacting at room temperature for 24-48 hours, discharging the product in anhydrous ethanol or anhydrous methanol, and crushing, washing and drying to obtain the soluble polyetheretherketone-1,3-dithiolane;

[0016] More preferably, the inert atmosphere is nitrogen;

[0017] More preferably, the crystalline polyetheretherketone has the following structural formula:

[0018]

[0019] Where n is a positive integer, 10≤n≤200;

[0020] More preferably, the concentration of the crystalline polyetheretherketone in the solvent to which the auxiliary agent is added is 0.05 g / ml-0.5 g / ml, the molar ratio of the carbonyl content of the crystalline polyetheretherketone to 1,2-ethanedithiol is 1:2-1:5, and the molar ratio of the boron trifluoride ether to 1,2-ethanedithiol is 1:3-1:1;

[0021] More preferably, the auxiliary agent is trifluoroacetic acid or trifluorobenzoic acid, the solvent is dichloromethane or chloroform, and the volume ratio of the auxiliary agent to the solvent is 1:10-1:5.

[0022] Preferably, in step (1), the polar solvent comprises a mixture of one or more of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide, and tetrahydrofuran in any proportion.

[0023] Preferably, in step (1), in the spinning solution, the mass fraction of soluble polyetheretherketone-1,3-dithiolane is 5%-30%, and the mass fraction of polyvinylpyrrolidone is 3%-5%.

[0024] Preferably, in step (1), the mixture is dispersed uniformly by stirring for 3-12 hours at a stirring speed of 500-1000 rpm;

[0025] More preferably, the stirring time is 6 h and the stirring speed is 1000 rpm.

[0026] Preferably, in step (2), the extrusion spinning method is wet spinning, and the degassing is vacuum degassing;

[0027] More preferably, the spinning solution after vacuum degassing is injected into the coagulation bath through a syringe and an injection pump to obtain polyetheretherketone-1,3-dithiolane wet gel fiber, the injection speed is 4-10 ml / h, and the diameter of the syringe needle is 0.41 mm-0.84 mm.

[0028] Preferably, in step (2), the coagulation bath is a mixture of one or more of the polar solvent, anhydrous ethanol, water, acetone, and methanol in step (1) in any proportion.

[0029] More preferably, the coagulation bath is an ethanol aqueous solution with a volume fraction of 10%-50%.

[0030] Preferably, in step (3), the displacement bath is a mixture of one or more of water, anhydrous ethanol, and methanol in any proportion;

[0031] More preferably, the displacement bath is an ethanol aqueous solution with a volume fraction of 10%-50%.

[0032] Preferably, in step (3), the solvent replacement time is 24-72 hours, and the replacement bath is replaced every 3-6 hours.

[0033] Preferably, in step (3), the freezing treatment is: placing in a -25°C to -40°C low-temperature refrigerator for 6-8 hours or in -196°C liquid nitrogen for 1-3 hours.

[0034] Preferably, in step (4), the drying is vacuum freeze drying, supercritical drying or atmospheric pressure drying;

[0035] More preferably, the drying is vacuum freeze drying, the vacuum degree is 0 Pa, the freeze drying temperature is -50°C to -70°C, and the drying time is 24-72h.

[0036] In a second aspect, the present invention provides polyetheretherketone aerogel fibers prepared by the above-mentioned method for preparing polyetheretherketone aerogel fibers.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The preparation method of the polyetheretherketone aerogel fiber provided by the invention has simple process and continuous subsequent process, and is expected to achieve large-scale production.

[0039] The aerogel fiber prepared by the present invention has a typical three-dimensional network structure, low linear density, high strength and good toughness, and good spinnability. Its porous structure provides the possibility for subsequent filling or adsorption of phase change materials for application in thermal insulation fields such as textiles and special clothing. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 The following are the SEM image (left) and digital image (right) of the knotted polyetheretherketone aerogel fibers in Example 1 of the present invention;

[0042] Figure 2 The cross-sectional morphology SEM image (left) and the local magnified SEM image (right) of the polyetheretherketone aerogel fiber in Example 3 of the present invention;

[0043] Figure 3 1 is a stress-strain diagram (left) of the tensile test of the polyetheretherketone aerogel fiber in Example 3 of the present invention and an optical image of a weight carrying 100 g (right);

[0044] Figure 4 This is a digital picture of a fabric woven from polyetheretherketone aerogel fibers in Example 1 of the present invention. DETAILED DESCRIPTION

[0045] In order to further understand the present invention, preferred embodiments of the present invention are described below, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the requirements of the present invention.

[0046] The preparation method of the polyetheretherketone aerogel fiber of the present invention comprises the following steps:

[0047] (1) dissolving soluble polyetheretherketone-1,3-dithiolane and polyvinylpyrrolidone in a polar solvent and stirring the mixture to obtain a spinning solution;

[0048] (2) vacuum degassing the spinning solution, extruding and spinning into a coagulation bath, and collecting by winding to obtain polyetheretherketone-1,3-dithiolane wet gel fiber;

[0049] (3) placing the polyetheretherketone-1,3-dithiolane wet gel fiber in a displacement bath for several solvent displacements, and freezing the fiber to obtain polyetheretherketone-1,3-dithiolane fiber;

[0050] (4) Drying the polyetheretherketone-1,3-dithiolane fiber to obtain polyetheretherketone aerogel fiber.

[0051] Preferably, in step (1), the preparation method of soluble polyetheretherketone-1,3-dithiolane is: under nitrogen protection, dissolving crystalline polyetheretherketone in a solvent to which an auxiliary agent is added, then adding boron trifluoride etherate and 1,2-ethanedithiol, reacting at room temperature for 24-48 hours, discharging the product in anhydrous ethanol or anhydrous methanol, crushing, washing and drying to obtain soluble polyetheretherketone-1,3-dithiolane; wherein the structural formula of the crystalline polyetheretherketone is as follows:

[0052]

[0053] Where n is a positive integer, 10≤n≤200;

[0054] The concentration of crystalline polyetheretherketone in the solvent to which the auxiliary agent is added is 0.05 g / ml-0.5 g / ml, the molar ratio of the carbonyl content of crystalline polyetheretherketone to 1,2-ethanedithiol is 1:2-1:5, and the molar ratio of boron trifluoride ether to 1,2-ethanedithiol is 1:3-1:1; the auxiliary agent is trifluoroacetic acid or trifluorobenzoic acid, the solvent is dichloromethane or chloroform, and the volume ratio of the auxiliary agent to the solvent is 1:10-1:5.

[0055] Preferably, in step (1), the polar solvent is a mixture of one or more of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide, and tetrahydrofuran in any proportion. However, it should be noted that there is no particular limitation on the selection of the polar solvent, as long as it can play a dissolving role.

[0056] Preferably, in step (1), in the spinning solution, the mass fraction of soluble polyetheretherketone-1,3-dithiolane is 5%-30%, and the mass fraction of polyvinylpyrrolidone is 3%-5%.

[0057] Preferably, in step (1), the dissolution of the soluble polyetheretherketone-1,3-dithiolane is achieved by stirring at room temperature, the stirring time is 6 hours, and the stirring speed is 500-1000 rpm. However, it should be noted that other methods that can achieve the dissolution and uniform dispersion of the soluble polyetheretherketone-1,3-dithiolane are also applicable to the present invention, such as ultrasound.

[0058] Preferably, in step (2), the extrusion spinning method is wet spinning, that is, the spinning solution after vacuum degassing is injected into a syringe, which is then injected into a coagulation bath by a syringe via a microinjection pump, and the spinning parameters are adjusted to achieve wet spinning. However, it should be noted that vacuum degassing is to maintain the continuity of the wet spinning process, and other degassing means are also applicable to the present invention, such as ultrasound. The preferred spinning parameters for wet spinning are: the spinning solution injection speed is 4-10 ml / h, the syringe needle diameter is 0.41 mm-0.84 mm, and the syringe needle is inserted 2 cm below the coagulation bath interface, which is selected according to actual conditions.

[0059] Preferably, in step (2), the coagulation bath is a mixture of one or more of the polar solvent, anhydrous ethanol, water, acetone, methanol and the like in step (1) in any proportion. More preferably, the coagulation bath is an aqueous solution of ethanol, and the volume fraction of ethanol is 10%-50%.

[0060] Preferably, in step (3), the displacement bath is a mixture of one or more of water, anhydrous ethanol, and methanol in any proportion, and more preferably the displacement bath is an aqueous solution of ethanol, and the volume fraction of ethanol is 10%-50%. The solvent replacement time is 24-72 hours, and the displacement bath is replaced every 3-6 hours.

[0061] Preferably, the freezing treatment is one of the following methods:

[0062] Place in liquid nitrogen for freezing treatment, the liquid nitrogen temperature is -196°C, the treatment time is 1-3 hours, and the preferred treatment time is 1 hour;

[0063] The product is placed in a low-temperature refrigerator for freezing treatment, the temperature of the low-temperature refrigerator is -25°C to -40°C, and the freezing time is 6h-8h; the more preferred freezing time is 6h.

[0064] Preferably, in step (4), the treatment method is vacuum freeze drying, the vacuum degree is 0Pa, the freeze drying temperature is -50°C to -70°C, and the drying time is 24-72h. The more preferred drying time is 48h. However, it should be noted that there is no special restriction on the subsequent treatment method, which mainly removes excess solvent on the basis of ensuring the three-dimensional network structure of aerogel fibers. Supercritical drying, normal pressure drying, etc. can also be selected.

[0065] The polyetheretherketone aerogel fiber of the present invention is prepared by the above method. While having the advantages of low density, high porosity, large specific surface area, etc. of aerogel, it also gives it a certain flexibility, so that it has great development space in the thermal insulation fields such as textiles and special clothing.

[0066] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with embodiments.

[0067] In the following examples, various processes and methods not described in detail are conventional methods known in the art. The materials, reagents, devices, instruments, equipment, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources. The structural formula of the polyetheretherketone used in the examples is as follows:

[0068]

[0069] Where n is a positive integer, 10≤n≤200;

[0070] Example 1

[0071] A method for preparing polyetheretherketone aerogel fiber, the steps are as follows:

[0072] Pour polyetheretherketone (28.8g, n=100) into 480ml dichloromethane in batches under nitrogen protection and magnetic stirring, add 60ml trifluoroacetic acid after uniform dispersion, and add 1,2-ethanedithiol (10.96ml, 0.25mol) and boron trifluoride ether (31.56ml, 0.25mol) to the solution in sequence after polyetheretherketone is fully dissolved to form a yellow viscous solution, react at room temperature for 24h and then discharge into 3000ml anhydrous ethanol. The obtained white solid is mechanically crushed and washed with anhydrous ethanol, and dried at 80℃ vacuum environment for 8h to obtain white solid polyetheretherketone-1,3-dithiolane.

[0073] At room temperature, 2 g of polyetheretherketone-1,3-dithiolane and 0.5 g of polyvinylpyrrolidone were dissolved in 17.5 g of N-methylpyrrolidone and stirred at room temperature for 6 hours. The obtained solution was vacuum degassed for 2 hours to obtain a spinning solution.

[0074] The spinning solution is extruded into a coagulation bath by using a syringe and a microinjection pump, the injection speed is 8 ml / h, the coagulation bath is an ethanol aqueous solution, the volume fraction of ethanol in the ethanol aqueous solution is 50%, and polyetheretherketone-1,3-dithiolane wet gel fiber is obtained; wherein the inner diameter of the needle of the syringe is 0.84 mm.

[0075] The polyetheretherketone-1,3-dithiolane wet gel fiber was subjected to a 24-hour solvent replacement treatment. The solvent replacement was carried out in an ethanol aqueous solution (ethanol volume fraction was 50%), and the solvent was changed every 6 hours, for a total of 4 solvent replacements. Then, the fiber was frozen in a low-temperature refrigerator at -25°C for 6 hours to obtain polyetheretherketone-1,3-dithiolane fiber.

[0076] The polyetheretherketone-1,3-dithiolane fiber was freeze-dried to obtain polyetheretherketone aerogel fiber, wherein the freeze-drying temperature was -50°C, the vacuum degree was 0Pa, and the freeze-drying was 48 hours. After testing, the obtained polyetheretherketone aerogel fiber had a tensile strength of 5.58MPa, an elongation at break of 21.73%, an elastic modulus of 61.90MPa, and a linear density of 16.7tex.

[0077] Example 2

[0078] A method for preparing polyetheretherketone aerogel fiber, the steps are as follows:

[0079] Pour polyetheretherketone (28.8g, n=100) into 480ml dichloromethane in batches under nitrogen protection and magnetic stirring, add 60ml trifluoroacetic acid after uniform dispersion, and add 1,2-ethanedithiol (10.96ml, 0.25mol) and boron trifluoride ether (31.56ml, 0.25mol) to the solution in sequence after polyetheretherketone is fully dissolved to form a yellow viscous solution, react at room temperature for 24h and then discharge into 3000ml anhydrous ethanol. The obtained white solid is mechanically crushed and washed with anhydrous ethanol, and dried at 80℃ vacuum environment for 8h to obtain white solid polyetheretherketone-1,3-dithiolane.

[0080] At room temperature, 3 g of polyetheretherketone-1,3-dithiolane and 0.5 g of polyvinylpyrrolidone were dissolved in 16.5 g of N-methylpyrrolidone and stirred at room temperature for 6 hours. The obtained solution was vacuum degassed for 2 hours to obtain a spinning solution.

[0081] The spinning solution is extruded into a coagulation bath by using a syringe and a microinjection pump, the injection speed is 8 ml / h, the coagulation bath is an ethanol aqueous solution, the volume fraction of ethanol in the ethanol aqueous solution is 50%, and polyetheretherketone-1,3-dithiolane wet gel fiber is obtained; wherein the inner diameter of the needle of the syringe is 0.84 mm.

[0082] The polyetheretherketone-1,3-dithiolane wet gel fiber was subjected to a 24-hour solvent replacement treatment. The solvent replacement was carried out in an ethanol aqueous solution (ethanol volume fraction was 50%), and the solvent was changed every 6 hours, for a total of 4 solvent replacements. Then, the fiber was frozen in a low-temperature refrigerator at -25°C for 6 hours to obtain polyetheretherketone-1,3-dithiolane fiber.

[0083] The polyetheretherketone-1,3-dithiolane fiber was freeze-dried to obtain polyetheretherketone aerogel fiber, wherein the freeze-drying temperature was -50°C, the vacuum degree was 0Pa, and the freeze-drying was 48 hours. After testing, the obtained polyetheretherketone aerogel fiber had a tensile strength of 5.81MPa, an elongation at break of 23.54%, an elastic modulus of 69.35MPa, and a linear density of 17.3tex.

[0084] Example 3

[0085] A method for preparing polyetheretherketone aerogel fiber, the steps are as follows:

[0086] Pour polyetheretherketone (28.8g, n=100) into 480ml dichloromethane in batches under nitrogen protection and magnetic stirring, add 60ml trifluoroacetic acid after uniform dispersion, and add 1,2-ethanedithiol (10.96ml, 0.25mol) and boron trifluoride ether (31.56ml, 0.25mol) to the solution in sequence after polyetheretherketone is fully dissolved to form a yellow viscous solution, react at room temperature for 24h and then discharge into 3000ml anhydrous ethanol. The obtained white solid is mechanically crushed and washed with anhydrous ethanol, and dried at 80℃ vacuum environment for 8h to obtain white solid polyetheretherketone-1,3-dithiolane.

[0087] At room temperature, 4 g of polyetheretherketone-1,3-dithiolane and 0.5 g of polyvinylpyrrolidone were dissolved in 15.5 g of N-methylpyrrolidone and stirred at room temperature for 6 hours. The obtained solution was vacuum degassed for 2 hours to obtain a spinning solution.

[0088] The spinning solution is extruded into a coagulation bath by using a syringe and a microinjection pump, the injection speed is 8 ml / h, the coagulation bath is an ethanol aqueous solution, the volume fraction of ethanol in the ethanol aqueous solution is 50%, and polyetheretherketone-1,3-dithiolane wet gel fiber is obtained; wherein the inner diameter of the needle of the syringe is 0.84 mm.

[0089] The polyetheretherketone-1,3-dithiolane wet gel fiber was subjected to a 24-hour solvent replacement treatment. The solvent replacement was carried out in an ethanol aqueous solution (ethanol volume fraction was 50%), and the solvent was changed every 6 hours, for a total of 4 solvent replacements. Then, the fiber was frozen in a low-temperature refrigerator at -25°C for 6 hours to obtain polyetheretherketone-1,3-dithiolane fiber.

[0090] The polyetheretherketone-1,3-dithiolane fiber was freeze-dried to obtain polyetheretherketone aerogel fiber, wherein the freeze-drying temperature was -50°C, the vacuum degree was 0Pa, and the freeze-drying was 48 hours. After testing, the obtained polyetheretherketone aerogel fiber had a tensile strength of 6.15MPa, an elongation at break of 25.81%, an elastic modulus of 76.11MPa, and a linear density of 18.6tex.

[0091] Example 4

[0092] A method for preparing polyetheretherketone aerogel fiber, the steps are as follows:

[0093] Pour polyetheretherketone (28.8g, n=100) into 480ml dichloromethane in batches under nitrogen protection and magnetic stirring, add 60ml trifluoroacetic acid after uniform dispersion, and add 1,2-ethanedithiol (10.96ml, 0.25mol) and boron trifluoride ether (31.56ml, 0.25mol) to the solution in sequence after polyetheretherketone is fully dissolved to form a yellow viscous solution, react at room temperature for 24h and then discharge into 3000ml anhydrous ethanol. The obtained white solid is mechanically crushed and washed with anhydrous ethanol, and dried at 80℃ vacuum environment for 8h to obtain white solid polyetheretherketone-1,3-dithiolane.

[0094] At room temperature, 4 g of polyetheretherketone-1,3-dithiolane and 0.5 g of polyvinylpyrrolidone were dissolved in 15.5 g of N-methylpyrrolidone and stirred at room temperature for 6 hours. The obtained solution was vacuum degassed for 2 hours to obtain a spinning solution.

[0095] The spinning solution is extruded into a coagulation bath using a syringe and a microinjection pump, the injection speed is 8 ml / h, the coagulation bath is an ethanol aqueous solution, the volume fraction of ethanol in the ethanol aqueous solution is 50%, and polyetheretherketone-1,3-dithiolane wet gel fiber is obtained; wherein the inner diameter of the needle of the syringe is 0.62 mm.

[0096] The polyetheretherketone-1,3-dithiolane wet gel fiber was subjected to a 24-hour solvent replacement treatment. The solvent replacement was carried out in an ethanol aqueous solution (ethanol volume fraction was 50%), and the solvent was changed every 6 hours, for a total of 4 solvent replacements. Then, the fiber was frozen in a low-temperature refrigerator at -25°C for 6 hours to obtain polyetheretherketone-1,3-dithiolane fiber.

[0097] The polyetheretherketone-1,3-dithiolane fiber was freeze-dried to obtain polyetheretherketone aerogel fiber, wherein the freeze-drying temperature was -50°C, the vacuum degree was 0Pa, and the freeze-drying was 48 hours. After testing, the obtained polyetheretherketone aerogel fiber had a tensile strength of 6.02MPa, an elongation at break of 24.98%, an elastic modulus of 71.25MPa, and a linear density of 17.9tex.

[0098] Example 5

[0099] A method for preparing polyetheretherketone aerogel fiber, the steps are as follows:

[0100] Pour polyetheretherketone (28.8g, n=100) into 480ml dichloromethane in batches under nitrogen protection and magnetic stirring, add 60ml trifluoroacetic acid after uniform dispersion, and add 1,2-ethanedithiol (10.96ml, 0.25mol) and boron trifluoride ether (31.56ml, 0.25mol) to the solution in sequence after polyetheretherketone is fully dissolved to form a yellow viscous solution, react at room temperature for 24h and then discharge into 3000ml anhydrous ethanol. The obtained white solid is mechanically crushed and washed with anhydrous ethanol, and dried at 80℃ vacuum environment for 8h to obtain white solid polyetheretherketone-1,3-dithiolane.

[0101] At room temperature, 4 g of polyetheretherketone-1,3-dithiolane and 0.5 g of polyvinylpyrrolidone were dissolved in 15.5 g of N-methylpyrrolidone and stirred at room temperature for 6 hours. The obtained solution was vacuum degassed for 2 hours to obtain a spinning solution.

[0102] The spinning solution is extruded into a coagulation bath by using a syringe and a microinjection pump, the injection speed is 8 ml / h, the coagulation bath is an ethanol aqueous solution, the volume fraction of ethanol in the ethanol aqueous solution is 50%, and polyetheretherketone-1,3-dithiolane wet gel fiber is obtained; wherein the inner diameter of the needle of the syringe is 0.51 mm.

[0103] The polyetheretherketone-1,3-dithiolane wet gel fiber was subjected to a 24-hour solvent replacement treatment. The solvent replacement was carried out in an ethanol aqueous solution (ethanol volume fraction was 50%), and the solvent was changed every 6 hours, for a total of 4 solvent replacements. Then, the fiber was frozen in a low-temperature refrigerator at -25°C for 6 hours to obtain polyetheretherketone-1,3-dithiolane fiber.

[0104] The polyetheretherketone-1,3-dithiolane fiber was freeze-dried to obtain polyetheretherketone aerogel fiber, wherein the freeze-drying temperature was -50°C, the vacuum degree was 0Pa, and the freeze-drying was 48 hours. After testing, the obtained polyetheretherketone aerogel fiber had a tensile strength of 5.75MPa, an elongation at break of 22.99%, an elastic modulus of 68.76MPa, and a linear density of 16.8tex.

[0105] Example 6

[0106] A method for preparing polyetheretherketone aerogel fiber, the steps are as follows:

[0107] Pour polyetheretherketone (28.8g, n=100) into 480ml dichloromethane in batches under nitrogen protection and magnetic stirring, add 60ml trifluoroacetic acid after uniform dispersion, and add 1,2-ethanedithiol (10.96ml, 0.25mol) and boron trifluoride ether (31.56ml, 0.25mol) to the solution in sequence after polyetheretherketone is fully dissolved to form a yellow viscous solution, react at room temperature for 24h and then discharge into 3000ml anhydrous ethanol. The obtained white solid is mechanically crushed and washed with anhydrous ethanol, and dried at 80℃ vacuum environment for 8h to obtain white solid polyetheretherketone-1,3-dithiolane.

[0108] At room temperature, 4 g of polyetheretherketone-1,3-dithiolane and 0.5 g of polyvinylpyrrolidone were dissolved in 15.5 g of N-methylpyrrolidone and stirred at room temperature for 6 hours. The obtained solution was vacuum degassed for 2 hours to obtain a spinning solution.

[0109] The spinning solution is extruded into a coagulation bath by using a syringe and a microinjection pump, the injection speed is 8 ml / h, the coagulation bath is an ethanol aqueous solution, the volume fraction of ethanol in the ethanol aqueous solution is 50%, and polyetheretherketone-1,3-dithiolane wet gel fiber is obtained; wherein the inner diameter of the needle of the syringe is 0.41 mm.

[0110] The polyetheretherketone-1,3-dithiolane wet gel fiber was subjected to a 24-hour solvent replacement treatment. The solvent replacement was carried out in an ethanol aqueous solution (ethanol volume fraction was 50%), and the solvent was changed every 6 hours, for a total of 4 solvent replacements. Then, the fiber was frozen in a low-temperature refrigerator at -25°C for 6 hours to obtain polyetheretherketone-1,3-dithiolane fiber.

[0111] The polyetheretherketone-1,3-dithiolane fiber was freeze-dried to obtain polyetheretherketone aerogel fiber, wherein the freeze-drying temperature was -50°C, the vacuum degree was 0Pa, and the freeze-drying was 48 hours. After testing, the obtained polyetheretherketone aerogel fiber had a tensile strength of 5.49MPa, an elongation at break of 21.65%, an elastic modulus of 60.77MPa, and a linear density of 16.3tex.

[0112] The polyetheretherketone aerogel fibers prepared in Examples 1-3 were examined by electron microscopy, and the results were as follows: Figure 1As shown in the middle left figure, it can be clearly observed that the fiber morphology of the prepared aerogel fiber does not change significantly after knotting, there is no breakage, the shape is regular and complete, and the optical image of the prepared aerogel fiber is observed, as shown in FIG. Figure 1 As shown in the right figure, no damage is observed on the surface of the aerogel fiber, indicating that the polyetheretherketone aerogel fiber prepared by the method of the present invention has good flexibility.

[0113] The fractured cross section of the polyetheretherketone aerogel fiber prepared in Example 3 was examined by electron microscopy, and the structure was as follows: Figure 2 As shown, from Figure 2 In the left figure, it can be observed that the prepared polyetheretherketone aerogel fiber has a porous structure and large finger-like pores can be observed. This is caused by the excessively fast exchange rate between the aerogel fiber spinning solution and the coagulation bath. However, there are also a large number of porous structures on the surface of the finger-like pores, and the pore diameter is about 1 μm. Figure 2 In the right figure, it can be observed that there are a large number of regular porous structures inside the prepared polyetheretherketone aerogel fiber, and the pore diameter is approximately about 1μm. This three-dimensional porous structure inside gives the polyetheretherketone aerogel fiber the advantages of low density and high porosity, and also provides conditions for the subsequent adsorption of phase change materials by the polyetheretherketone aerogel fiber to achieve thermal management.

[0114] The polyetheretherketone aerogel fiber prepared in Example 3 was subjected to stress and strain testing. The testing structure is as follows: Figure 3 As shown in the left figure, Figure 3 The left figure shows that the prepared polyetheretherketone aerogel fiber has certain mechanical properties. Figure 3 From the optical image on the right, it can be observed that the prepared polyetheretherketone aerogel fiber can withstand a weight of 100g, which also shows that the aerogel fiber has a certain mechanical strength.

[0115] The polyetheretherketone aerogel fiber prepared in Example 1 was woven and its optical image was observed. Figure 4 As shown, from Figure 4 It can be observed that the prepared polyetheretherketone aerogel fiber can be woven into fabric, and the fiber structure remains intact and regular, and no damage is found in the fiber. The prepared aerogel fiber has certain weavability.

[0116] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the embodiments. For those skilled in the art, different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for preparing polyetheretherketone aerogel fiber, characterized in that: The following steps are involved: (1) dissolving soluble polyetheretherketone-1,3-dithiolane and polyvinylpyrrolidone in a polar solvent and dispersing them uniformly to obtain a spinning solution; (2) after degassing the spinning solution, extruding and spinning into a coagulation bath, and collecting by winding to obtain polyetheretherketone-1,3-dithiolane wet gel fiber; (3) placing the polyetheretherketone-1,3-dithiolane wet gel fiber in a displacement bath for several solvent displacements, and freezing the fiber to obtain polyetheretherketone-1,3-dithiolane fiber; (4) Drying the polyetheretherketone-1,3-dithiolane fiber to obtain polyetheretherketone aerogel fiber.

2. The method for preparing polyetheretherketone aerogel fiber according to claim 1, characterized in that: In step (1), the preparation method of the soluble polyetheretherketone-1,3-dithiolane is as follows: under the protection of an inert atmosphere, dissolving the crystalline polyetheretherketone in a solvent to which an auxiliary agent is added, then adding boron trifluoride etherate and 1,2-ethanedithiol, reacting at room temperature for 24-48 hours, discharging the product in anhydrous ethanol or anhydrous methanol, and crushing, washing and drying the product to obtain the soluble polyetheretherketone-1,3-dithiolane; The inert atmosphere is nitrogen; The structural formula of the crystalline polyetheretherketone is as follows: Where n is a positive integer, 10≤n≤200; The concentration of the crystalline polyetheretherketone in the solvent to which the auxiliary agent is added is 0.05 g / ml-0.5 g / ml, the molar ratio of the carbonyl content of the crystalline polyetheretherketone to 1,2-ethanedithiol is 1:2-1:5, and the molar ratio of boron trifluoride ether to 1,2-ethanedithiol is 1:3-1:1; The auxiliary agent is trifluoroacetic acid or trifluorobenzoic acid, the solvent is dichloromethane or chloroform, and the volume ratio of the auxiliary agent to the solvent is 1:10-1:

5.

3. The method for preparing polyetheretherketone aerogel fiber according to claim 1, characterized in that: In step (1), The polar solvent includes a mixture of one or more of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide, and tetrahydrofuran in any proportion; In the spinning solution, the mass fraction of soluble polyetheretherketone-1,3-dithiolane is 5%-30%, and the mass fraction of polyvinylpyrrolidone is 3%-5%; The mixture was dispersed uniformly by stirring for 6 hours at a speed of 500-1000 rpm.

4. The method for preparing polyetheretherketone aerogel fiber according to claim 1, characterized in that: In step (2), The extrusion spinning method is wet spinning; The coagulation bath is a mixture of one or more of the polar solvent, anhydrous ethanol, water, acetone, and methanol in step (1) in any proportion; The degassing is vacuum degassing.

5. The method for preparing polyetheretherketone aerogel fiber according to claim 4, characterized in that: The spinning solution after vacuum degassing is injected into the coagulation bath through a syringe and a syringe pump to obtain polyetheretherketone-1,3-dithiolane wet gel fiber, the injection speed is 4-10 ml / h, and the diameter of the syringe needle is 0.41 mm-0.84 mm; The coagulation bath is an ethanol aqueous solution with a volume fraction of 10%-50%.

6. The method for preparing polyetheretherketone aerogel fiber according to claim 1, characterized in that: In step (3), The displacement bath is a mixture of one or more of water, anhydrous ethanol and methanol in any proportion; The solvent replacement time is 24-72 hours, and the replacement bath is replaced every 3-6 hours; The freezing treatment is: placing in a -25°C to -40°C low-temperature refrigerator for 6-8 hours or placing in -196°C liquid nitrogen for 1-3 hours.

7. The method for preparing polyetheretherketone aerogel fiber according to claim 6, characterized in that: The displacement bath is an ethanol aqueous solution with a volume fraction of 10%-50%.

8. The method for preparing polyetheretherketone aerogel fiber according to claim 1, characterized in that: In step (4), the drying is vacuum freeze drying, supercritical drying or normal pressure drying.

9. The method for preparing polyetheretherketone aerogel fiber according to claim 8, characterized in that: The drying is vacuum freeze drying, the vacuum degree is 0Pa, the freeze drying temperature is -50°C to -70°C, and the drying time is 24-72h.

10. Polyetheretherketone aerogel fiber prepared according to the method for preparing polyetheretherketone aerogel fiber according to any one of claims 1 to 9.

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