A method for preparing a high-temperature resistant hollow heat-insulating fiber fabric

Abstract

This invention relates to the field of fabric production technology, specifically to a method for preparing a high-temperature resistant hollow heat-insulating fiber fabric. The method includes: preparing a spinning solution with polyacrylonitrile as the shell and a styrene-acrylonitrile copolymer containing a heat-insulating agent as the core layer; forming core-shell fibers through coaxial electrospinning, followed by oxidation and carbonization treatment to decompose the core layer, obtaining hollow carbon fibers filled with a heat-insulating agent; treating the fibers with a flame-retardant finishing solution, then spinning and knitting them into fabric, followed by finishing processes such as napping and pelletizing to obtain the final fabric; wherein the heat-insulating agent is prepared by a sol-gel method using zirconium oxynitrate, yttrium nitrate, spherical hollow graphene, and nano-titanium carbide, exhibiting highly efficient heat-blocking properties; the high-temperature resistant hollow heat-insulating fiber fabric prepared by this invention not only possesses lightweight and soft characteristics and good wearing comfort, but also has excellent high-temperature resistance, heat insulation, and flame-retardant properties, effectively ensuring the quality of the fiber fabric.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of fabric production, in particular to a preparation method of high-temperature-resistant hollow heat-insulating fiber fabric. BACKGROUND

[0002] High-temperature-resistant and heat-insulating performance of protective clothing is required in high-temperature operation fields such as fire fighting, metallurgy, welding and aerospace. Traditional heat-insulating materials such as asbestos have been eliminated due to carcinogenicity, and some new inorganic fibers or aramid fibers have good heat resistance, but their heat-insulating performance often depends on the thickness of the materials, resulting in heavy clothing and affecting operation flexibility.

[0003] Electrospinning technology can prepare micro-nano scale fibers, and coaxial electrospinning can prepare fibers with a core-shell structure. If a pyrolyzable component is used as the core layer, a hollow structure can be formed after carbonization, which can effectively reduce the solid heat conduction of the material and improve the heat-insulating performance. However, the single hollow structure has limited blocking effect on heat radiation, and the flame-retardant performance and wearing comfort (such as softness) of the fiber itself are relatively insufficient, and further improvement or improvement is still needed.

[0004] Based on the above, the application provides a preparation method of high-temperature-resistant hollow heat-insulating fiber fabric to solve the above technical problems. SUMMARY

[0005] The high-temperature-resistant hollow heat-insulating fiber fabric prepared by the application not only has the characteristics of light weight and softness, and good wearing comfort, but also has excellent high-temperature-resistant performance, heat-insulating performance and flame-retardant performance, effectively ensuring the quality and quality of the fiber fabric.

[0006] To achieve the above purpose, the application provides the following technical scheme:

[0007] A preparation method of high-temperature-resistant hollow heat-insulating fiber fabric, comprising the following steps:

[0008] Step one, polyacrylonitrile is added to an organic solvent in a dosage of 6-12 wt%, to prepare a shell layer spinning solution; styrene-acrylonitrile copolymer is added to an organic solvent to prepare a copolymer solution, and a heat-insulating agent with a mass of 10-20% of the copolymer solution is added to the copolymer solution, and the mixture is uniformly dispersed to obtain a core layer spinning solution; the mass concentration of the copolymer solution is 10-20% of the mass concentration of the shell layer spinning solution;

[0009] Step two, coaxial electrospinning process is used to prepare a composite fiber with a core-shell structure from the shell layer spinning solution and the core layer spinning solution, and the composite fiber is subjected to oxidation and carbonization treatment to obtain a hollow carbon fiber;

[0010] Step three, the hollow carbon fiber is immersed in the flame-retardant finishing liquid for 10-15 min, taken out, dried and made into yarn, the obtained hollow carbon fiber yarn is knitted into a base fabric, and the base fabric is made into a high-temperature-resistant thermal insulation fabric after being subjected to high-temperature setting, raising, raising, cutting, shaking and setting in sequence.

[0011] Further, the preparation method of the thermal insulation agent is as follows: zirconium oxynitrate is put into a 3-5wt% poloxamer 407 aqueous solution at a dosage of 2-5wt%, yttrium nitrate with a mass of 6-10% of the zirconium oxynitrate, 10-15% spherical hollow graphene, 3-5% nano-titanium carbide with a particle size of 20-30nm are added, and then the mixture is uniformly mixed, the pH value is adjusted to 4-4.5 by acetic acid, then 0.3-0.8% of the zirconium oxynitrate of methyl ethylene oxide is added, and the pH value of the reaction system is neutralized at 50-70℃ by stirring, the obtained gelatinous product is continuously reacted at 65-75℃ for 6-15h, and then the product is freeze-dried and crushed.

[0012] Further, the preparation method of the spherical hollow graphene is as follows: sucrose, polyethylene glycol, ferric chloride and deionized water are added into a reactor at a mass ratio of 1:3-6:0.2-0.5:20-50, and the obtained mixture is reacted at 150-200℃ for 6-10h, after the reaction is completed, the reaction liquid is filtered, the filter cake is microwave-heated at 350-500℃ for 5-10min, and then taken out after cooling and sintered at high temperature under the protection of nitrogen, and then cooled to room temperature after sintering, the obtained solid powder is soaked in 1-1.5mol / L hydrochloric acid solution for 8-12h, and then washed with water and dried to obtain the product.

[0013] Further, the configuration temperature of the shell spinning solution and the copolymer solution is 50-80℃, and the organic solvent is N,N-dimethylformamide.

[0014] Further, the thermal insulation agent is dispersed by ultrasonic at a frequency of 20-30kHz for 2-4h after being added into the copolymer solution.

[0015] Further, the spinning speed of the shell spinning solution and the core spinning solution is 0.5-1.5mL / h, the spinning voltage is set to 15-25kV, and the distance from the spinneret to the collector is set to 15-25cm.

[0016] Further, the oxidation treatment method of the composite fiber is as follows: the temperature is increased to 200-300℃ at a temperature increasing rate of 5-10℃ / min, and the composite fiber is treated at this temperature for 1-3h.

[0017] Further, the carbonization treatment method of the composite fiber is: under the protection of nitrogen, the temperature is increased to 600-800 DEG C at a temperature increasing speed of 5-20 DEG C / min, and the composite fiber is treated at this temperature for 2-4h.

[0018] Further, the spinning stream obtained when the coaxial electrospinning is performed enters a coagulation bath, a preheating bath, a washing tank and a drawing bath in sequence, and then the composite fiber is prepared after oiling, drying, crimping, steam heat setting, oiling and drying treatment;

[0019] Wherein, the steam pressure during the steam heat setting is 0.2-0.3 MPa, and the setting time is 20-30 min.

[0020] The coagulation bath is a 30-40wt% N,N-dimethylformamide aqueous solution, and the temperature is 20-25 DEG C.

[0021] The specific composition of the preheating bath is 5-10wt% N,N-dimethylformamide, 2-3wt% sodium dodecyl benzene sulfonate, and the balance is water; the temperature is 60-65 DEG C.

[0022] The water temperature of the washing tank is 50-65 DEG C.

[0023] The drawing bath is a 2-3wt% sodium dodecyl benzene sulfonate aqueous solution, and the temperature is 95-98 DEG C; the drawing multiple is 5-7 times.

[0024] Further, the preparation method of the flame-retardant finishing liquid is: acrylic acid is added into deionized water at a dosage ratio of 0.8-1.2mol / L, then dimethyl vinyl phosphonate is added at a molar amount of 0.3-0.5 times of the acrylic acid, the mixture is uniformly mixed at 80 DEG C, and then the obtained mixture and 0.2-0.5% of ammonium persulfate with a mass of 0.2-0.5% of the total mass of the acrylic acid and the dimethyl vinyl phosphonate are added into deionized water with a volume of 1-2 times of the mixture at 80 DEG C, and the reaction is carried out for 3-5h, and then the mixture is naturally cooled to room temperature, and the flame-retardant finishing liquid is obtained.

[0025] Compared with the prior art, the beneficial effects of the present application are:

[0026] 1. The present application uses sucrose, polyethylene glycol, ferric chloride and other raw materials to prepare spherical hollow graphene, then adds yttrium nitrate and nano titanium carbide into the poloxamer 407 aqueous solution containing zirconyl nitrate, and after chemical reaction, a heat insulating agent with an average particle size of 156-182 nm and an average pore size of 18-32 nm is prepared. The heat insulating agent takes porous zirconia aerogel as the main structure, and spherical hollow graphene and nano titanium carbide are uniformly dispersed in the inside. The zirconia aerogel has the characteristics of light weight and excellent heat barrier function, and the hollow cavity structure of the spherical hollow graphene can effectively block heat conduction, and the nano titanium carbide has excellent reflection effect on heat radiation. Under the synergistic effect of the spherical hollow graphene and the nano titanium carbide, the heat flows at a very low speed in the porous channels of the zirconia aerogel under the cooperation of the double effects of reflection and blocking, and when the heat flows in the zirconia aerogel, the internal through holes and blind hole structures cooperate with each other to produce a strong labyrinth effect, further slowing down the flow rate of heat in the heat insulating agent, which effectively ensures the heat barrier performance of the heat insulating agent.

[0027] 2. The present application uses the coaxial electrospinning process to prepare hollow carbon fibers with a diameter of 1-5 μm and a shell thickness of 47-272 nm, and fills the heat insulating additives in the inside. Under the synergistic cooperation of the special structure of the heat insulating agent and the hollow structure of the carbon fiber, the solid heat conduction of the fiber is greatly reduced, forming a micron-scale heat barrier, effectively improving the high temperature resistance of the prepared fiber fabric. At the same time, the heat insulating agent, the hollow carbon fiber and the flame retardant in the flame retardant finishing liquid synergize with each other, further improving the flame retardant performance of the prepared fiber fabric.

[0028] 3. After the hollow carbon fiber is made into yarn and knitted into fabric, a layer of fluffy and dense short nap is formed on the surface of the fabric through the finishing processes such as raising, raising and shaking. This layer of nap can effectively capture a large amount of stationary air, forming a thick air heat insulation layer on the surface of the fabric, which can further block the transmission of external heat, improving the heat insulation performance and thermal insulation performance of the fiber fabric. At the same time, the fiber fabric is also more light and soft, effectively improving the wearing comfort and operation flexibility. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is the real picture of the high-temperature-resistant hollow heat-insulating fiber fabric prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0031] Embodiment 1

[0032] A preparation method of a high-temperature-resistant hollow heat-insulating fiber fabric, comprising the following steps:

[0033] Step one, polyacrylonitrile is added into an organic solvent in a dosage of 6wt%, to prepare a shell layer spinning solution; styrene-acrylonitrile copolymer is added into an organic solvent to prepare a copolymer solution, and 10wt% of heat insulating agent is added into the copolymer solution, and the heat insulating agent is uniformly dispersed to obtain a core layer spinning solution; the mass concentration of the copolymer solution is 10% of the mass concentration of the shell layer spinning solution;

[0034] The configuration temperature of the shell layer spinning solution and the copolymer solution is 60℃, and the organic solvent is N,N-dimethylformamide;

[0035] After the heat insulating agent is added into the copolymer solution, ultrasonic dispersion is performed at a frequency of 20kHz for 4h;

[0036] The spinning speed of the shell layer spinning solution and the core layer spinning solution is 0.5mL / h, the spinning voltage is set to 15kV, and the distance from the spinneret to the collector is set to 15cm;

[0037] Step two, the shell layer spinning solution and the core layer spinning solution are prepared into a composite fiber with a core-shell structure by using a coaxial electrospinning process, and the composite fiber is treated by oxidation and carbonization to obtain a hollow carbon fiber with a diameter of 1μm and a shell thickness of 50nm;

[0038] The oxidation treatment method of the composite fiber is that the temperature is raised to 200℃ at a temperature raising speed of 5℃ / min, and the composite fiber is treated at this temperature for 3h;

[0039] The carbonization treatment method of the composite fiber is that the temperature is raised to 600℃ at a temperature raising speed of 5℃ / min under the protection of nitrogen, and the composite fiber is treated at this temperature for 4h;

[0040] The spinning stream obtained during the coaxial electrospinning enters a coagulation bath, a preheating bath, a washing tank and a stretching bath in sequence, and then the composite fiber is prepared after oiling, drying, crimping, steam heat setting, oiling and drying treatment.

[0041] The steam pressure during the steam heat setting is 0.2MPa, and the setting time is 30min;

[0042] The coagulation bath is a 30wt% aqueous solution of N,N-dimethylformamide, and the temperature is 20℃;

[0043] The specific composition of the preheating bath is 5wt% N,N-dimethylformamide, 2wt% sodium dodecyl benzene sulfonate, and the balance is water; the temperature is 60℃;

[0044] The water temperature of the water washing tank is 50℃;

[0045] The stretching bath is a 2wt% aqueous solution of sodium dodecyl benzene sulfonate, and the temperature is 95℃; the stretching multiple is 5 times;

[0046] Step three, immerse the hollow carbon fiber into the flame-retardant finishing liquid for 10 minutes, take it out, dry it, and make 32s / 1 hollow carbon fiber yarn, knit the obtained hollow carbon fiber yarn into a base cloth, and make a high-temperature-resistant thermal-insulation fiber fabric after the base cloth is sequentially subjected to high-temperature setting, raising, raising, cutting, shaking, and setting;

[0047] The preparation method of the flame-retardant finishing liquid is as follows: add acrylic acid into deionized water according to the dosage ratio of 0.8mol / L, then add dimethyl vinyl phosphonate with a molar amount of 0.3 times that of the acrylic acid, mix uniformly at 80℃, and then within 2h, add the obtained mixed solution and 0.2% of ammonium persulfate with a mass of 0.2% of the total mass of the acrylic acid and dimethyl vinyl phosphonate into deionized water with the same volume as the mixed solution, and then naturally cool to room temperature after being kept at 80℃ for 3h, thus obtaining the flame-retardant finishing liquid.

[0048] The preparation method of the thermal insulation agent is as follows: put zirconyl nitrate with a mass fraction of 2% into a 3wt% aqueous solution of poloxamer 407, add yttrium nitrate with a mass of 6% of the mass of the zirconyl nitrate, 10% spherical hollow graphene, and 3% nano titanium carbide with a particle size of 20nm, mix uniformly, then adjust the pH to 4 with acetic acid, then add methyl ethylene oxide with a mass of 0.3% of the mass of the zirconyl nitrate, and stir at 50℃ until the pH of the reaction system is neutral, continue to react the obtained gelatinous product at 65℃ for 15h, then freeze-dry and crush the product, thus obtaining a thermal insulation agent with a particle size of 156nm and a pore size of 18nm; the temperature of the freeze-drying is -60℃, and the drying time is 2 days;

[0049] The preparation method of the spherical hollow graphene is as follows: add sucrose, polyethylene glycol, ferric chloride, and deionized water into a reactor according to a mass ratio of 1:3:0.2:20, mix uniformly, then react the obtained mixed components at 150℃ for 10h; after the reaction is completed, filter the reaction solution, microwave heat the filter cake at 350℃ for 10min, take it out after cooling, and perform high-temperature sintering under the protection of nitrogen, then cool to room temperature after sintering is completed, soak the obtained solid powder in a 1mol / L hydrochloric acid solution for 12h, and then perform water washing and drying treatment, thus obtaining the product.

[0050] Example 2

[0051] The preparation method of the high-temperature-resistant hollow heat-insulating fiber fabric provided in this embodiment is basically the same as that in Embodiment 1, except that the concentration ratio of the copolymer solution to the shell spinning solution is different from that in Embodiment 1, and the amount of the heat-insulating agent and the preparation method thereof are also different from those in Embodiment 1.

[0052] In this embodiment, the amount of the heat-insulating agent added is 15% of the copolymer solution, and the mass concentration of the copolymer solution is 15% of the mass concentration of the shell spinning solution.

[0053] The preparation method of the heat-insulating agent is as follows: zirconyl nitrate is put into a 4wt% poloxamer 407 aqueous solution at a dosage of 3wt%, yttrium nitrate with a mass of 8% of the zirconyl nitrate, 12% spherical hollow graphene, and 4% nano-titanium carbide with a particle size of 20nm are added, the mixture is uniformly mixed, and then acetic acid is added to adjust the pH to 4.2, then methyl oxirane with a mass of 0.5% of the zirconyl nitrate is added, and the pH of the reaction system is neutralized at 60℃, the obtained gelatinous product is continuously reacted at 70℃ for 10h, and then the product is freeze-dried and crushed, thereby obtaining a heat-insulating agent with a particle size of 173nm and a pore size of 26nm; wherein the temperature for freeze-drying is -55℃, and the drying time is 3 days.

[0054] The preparation method of the spherical hollow graphene is as follows: sucrose, polyethylene glycol, ferric chloride and deionized water are added into a reactor at a mass ratio of 1:5:0.3:40, the obtained mixture is uniformly mixed, and then the mixture is reacted at 180℃ for 8h; after the reaction is completed, the reaction liquid is filtered, the filter cake is subjected to microwave heating at 450℃ for 10min, and then the filter cake is taken out and subjected to high-temperature sintering under the protection of nitrogen, and then the sintered product is cooled to room temperature, and then the obtained solid powder is soaked in a 1.2mol / L hydrochloric acid solution for 10h, and then the product is subjected to water washing and drying treatment.

[0055] Embodiment 3

[0056] The preparation method of the high-temperature-resistant hollow heat-insulating fiber fabric provided in this embodiment is basically the same as that in Embodiment 1, except that the concentration ratio of the copolymer solution to the shell spinning solution is different from that in Embodiment 1, and the amount of the heat-insulating agent and the preparation method thereof are also different from those in Embodiment 1.

[0057] In this embodiment, the amount of the heat-insulating agent added is 20% of the copolymer solution, and the mass concentration of the copolymer solution is 20% of the mass concentration of the shell spinning solution.

[0058] The preparation method of the thermal insulation agent is as follows: zirconium oxynitrate is put into a 5wt% poloxamer 407 aqueous solution at a dosage of 5wt%, yttrium nitrate with a mass of 10% of the zirconium oxynitrate, 15% spherical hollow graphene, and 5% nano titanium carbide with a particle size of 20 nm are added, the mixture is uniformly mixed, acetic acid is used to adjust the pH to 4.5, then 0.8% of the zirconium oxynitrate of methyl oxirane is added, the pH of the reaction system is neutralized at 70°C, the obtained colloidal product is continuously reacted at 75°C for 6h, then the product is freeze-dried and crushed, and the thermal insulation agent with a particle size of 182nm and a pore size of 32nm is obtained; wherein the temperature of freeze-drying is -50°C, and the drying time is 4 days.

[0059] The preparation method of the spherical hollow graphene is as follows: sucrose, polyethylene glycol, iron chloride and deionized water are added into a reactor at a mass ratio of 1:6:0.5:50, the obtained mixture is reacted at 200°C for 6h, after the reaction is completed, the reaction liquid is filtered, the filter cake is microwave-heated at 500°C for 5min, then it is taken out after cooling and sintered at high temperature under the protection of nitrogen, after sintering, it is cooled to room temperature, the obtained solid powder is soaked in a 1.5mol / L hydrochloric acid solution for 8h, and then it is washed with water and dried to obtain the product.

[0060] Comparative Example 1: The difference between this comparative example and Example 1 is that no thermal insulation agent is added in the copolymer solution in this comparative example.

[0061] Comparative Example 2: The difference between this comparative example and Example 1 is that the same amount of ordinary graphene with an average particle size of 20nm is used instead of spherical hollow graphene in this comparative example.

[0062] Comparative Example 3: The difference between this comparative example and Example 1 is that the thermal insulation agent added in this comparative example does not contain nano titanium carbide.

[0063] Performance test: the related properties of the high-temperature-resistant hollow thermal insulation fabric samples provided in Examples 1-3 and Comparative Examples 1-3 are tested as follows, and the data obtained by the above tests are recorded in Tables 1 and 2:

[0064] 1. Fabric flame-retardant property: each group of high-temperature-resistant hollow thermal insulation fabric samples is tested according to GB / T 5455-2014 standard;

[0065] 2. Fabric burst strength: each group of high-temperature-resistant hollow thermal insulation fabric samples is tested according to GB / T 7742.1-2005 standard;

[0066] 3. Fabric thermal protective performance value (TPP): each group of high-temperature-resistant hollow thermal insulation fabric samples is tested according to GB / T 38302-2019 standard.

[0067] Table 1 is the flame retardant performance and bursting strength data of each group of fabric samples

[0068]

[0069] Table 2 is the thermal protective performance value of each group of fabrics and the fabric comfort and touch performance

[0070]

[0071] By comparing and analyzing the related data in the table, it can be known that the high-temperature-resistant hollow heat-insulating fiber fabric prepared by the preparation method has excellent high-temperature resistance, heat insulation and flame retardant performance, and effectively ensures the quality and quality of the fiber fabric. Therefore, the preparation method of the high-temperature-resistant hollow heat-insulating fiber fabric provided by the application has a broader market prospect and is more suitable for promotion.

[0072] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0073] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details, nor limit the application to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of the present specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. A method for producing a high-temperature-resistant hollow thermal- insulation fiber fabric, characterized by comprising the steps of: The method comprises the following steps: ​ Step 1: polyacrylonitrile is added into an organic solvent in a proportion of 6-12 wt% to prepare a shell spinning solution; styrene-acrylonitrile copolymer is added into an organic solvent to prepare a copolymer solution, and a heat insulating agent with a mass of 10-20% of the copolymer solution is added into the copolymer solution to prepare a core spinning solution; the mass concentration of the copolymer solution is 10-20% of the mass concentration of the shell spinning solution; Step 2: the shell spinning solution and the core spinning solution are prepared into a composite fiber with a core-shell structure by using a coaxial electrospinning process, and the composite fiber is treated by oxidation and carbonization to obtain a hollow carbon fiber; Step 3: the hollow carbon fiber is immersed in a flame-retardant finishing solution for 10-15 min, taken out, dried and spun into a yarn, the obtained hollow carbon fiber yarn is knitted into a base cloth, and the base cloth is subjected to high-temperature setting, raising, raising, shearing, shaking and setting in sequence to obtain a high-temperature-resistant heat-insulating fabric; The heat insulating agent is prepared by the following method: zirconium oxynitrate is added into a 3-5 wt% poloxamer 407 aqueous solution in a proportion of 2-5 wt%, and yttrium nitrate with a mass of 6-10% of the zirconium oxynitrate, spherical hollow graphene with a mass of 10-15% of the zirconium oxynitrate, and nano-titanium carbide with a mass of 3-5% of the zirconium oxynitrate are added into the solution, the mixture is uniformly mixed, acetic acid is added to adjust the pH of the mixture to 4-4.5, and then methyl ethylene oxide with a mass of 0.3-0.8% of the zirconium oxynitrate is added, the mixture is stirred at 50-70℃ until the pH of the reaction system is neutral, the obtained gelatinous product is continuously reacted at 65-75℃ for 6-15 h, and then the product is subjected to freeze-drying and crushing; The spherical hollow graphene is prepared by the following method: sucrose, polyethylene glycol, ferric chloride and deionized water are added into a reactor in a mass ratio of 1:3-6:0.2-0.5:20-50, the obtained mixture is reacted at 150-200℃ for 6-10 h, the reaction liquid is filtered, the filter cake is subjected to microwave heating at 350-500℃ for 5-10 min, the filter cake is taken out after cooling, and high-temperature sintering is performed on the filter cake under the protection of nitrogen, the sintered product is cooled to room temperature after sintering, the obtained solid powder is soaked in a 1-1.5 mol / L hydrochloric acid solution for 8-12 h, and then the solid powder is subjected to water washing and drying to obtain the spherical hollow graphene.

2. The method for preparing a high-temperature resistant hollow heat-insulating fiber fabric according to claim 1, characterized in that, The configuration temperature of the shell spinning solution and the copolymer solution is 50-80℃, and the organic solvent is N,N-dimethylformamide.

3. The method for preparing a high-temperature resistant hollow heat-insulating fiber fabric according to claim 1, characterized in that: The heat insulating agent is ultrasonically dispersed in the copolymer solution for 2-4 h at a frequency of 20-30 kHz.

4. The method for preparing a high-temperature resistant hollow heat-insulating fiber fabric according to claim 1, characterized in that: The spinning speed of the shell spinning solution and the core spinning solution is 0.5-1.5 mL / h, the spinning voltage is set to 15-25 kV, and the distance between the spinneret and the collector is set to 15-25 cm.

5. The method for preparing a high-temperature resistant hollow heat-insulating fiber fabric according to claim 1, characterized in that, The oxidation treatment method of the composite fiber is as follows: the temperature is raised to 200-300℃ at a temperature rising speed of 5-10℃ / min, and the composite fiber is treated at this temperature for 1-3 h.

6. The method for preparing a high-temperature resistant hollow heat-insulating fiber fabric according to claim 1, characterized in that, The carbonization treatment method of the composite fiber is as follows: the temperature is raised to 600-800℃ at a temperature rising speed of 5-20℃ / min under the protection of nitrogen, and the composite fiber is treated at this temperature for 2-4 h.

7. The method for preparing a high-temperature resistant hollow heat-insulating fiber fabric according to claim 1, characterized in that: The spinning fluid obtained in the coaxial electrostatic spinning is sequentially introduced into a coagulating bath, a preheating bath, a washing tank and a drawing bath, and then is subjected to oiling, drying, crimping, steam heat setting, oiling and drying to obtain the composite fiber.

8. The method for preparing a high-temperature resistant hollow heat-insulating fiber fabric according to claim 1, characterized in that, The preparation method of the flame-retardant finishing liquid is as follows: acrylic acid is added into deionized water in a dosage ratio of 0.8-1.2 mol / L, then dimethyl vinyl phosphonate with a molar amount of 0.3-0.5 times that of the acrylic acid is added, the mixture is uniformly mixed at 80 DEG C, and then the obtained mixture and 0.2-0.5% of ammonium persulfate by mass of the total mass of the acrylic acid and the dimethyl vinyl phosphonate are added into deionized water with a volume of 1-2 times that of the mixture within 2-3 hours, and the mixture is kept at 80 DEG C for 3-5 hours, and then is naturally cooled to room temperature to obtain the flame-retardant finishing liquid.

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