Hollow silicon carbide ceramic fiber and preparation method and application thereof

Abstract

The application relates to a hollow silicon carbide ceramic fiber and a preparation method and application thereof, and the preparation method of the hollow silicon carbide ceramic fiber is as follows: organic silicon resin is melt-spun in an inert atmosphere; heat crosslinking and solidification treatment is carried out at a predetermined temperature; heat decomposition is carried out in the inert atmosphere at a predetermined temperature rising speed until the temperature is raised to a predetermined temperature; sintering treatment is carried out in the inert atmosphere at a predetermined temperature rising speed until the temperature is raised to a predetermined temperature, a silicon carbide-carbon ceramic composite fiber with carbon-rich core is generated; oxidation and decarburization treatment is carried out at a predetermined temperature rising speed until the temperature is raised to a predetermined temperature, free carbon in the fiber is removed, and a hollow-structure silicon carbide ceramic fiber is generated. The application has low cost and simple process, the prepared hollow silicon carbide ceramic fiber has good mechanical properties, and compared with the dense silicon carbide fiber in the prior art, the application is suitable for the fields of high-temperature heat insulation materials and catalytic adsorption materials.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fiber materials, and particularly relates to a hollow silicon carbide ceramic fiber and a preparation method and application thereof. BACKGROUND

[0002] Silicon carbide fibers have the advantages of high temperature resistance, oxidation resistance, corrosion resistance, good mechanical properties, and good compatibility with metal, ceramic, polymer and other composite material matrices, and are ideal reinforcing materials, and have wide application prospects in the fields of aerospace and nuclear industry.

[0003] In addition to the above advantages, the hollow silicon carbide ceramic fiber also has a special hollow structure, and can be used for high-temperature thermal insulation materials and catalytic adsorption materials. At present, the methods for preparing the hollow silicon carbide ceramic fiber include the following: using polycarbosilane as a raw material to prepare a polymer mixed fiber through precursor blending, and then heat treating the polymer mixed fiber at a high temperature to prepare the hollow fiber (such as patent CN 109023590 B); using a strong oxidizing agent or halogenation reaction to crosslink the polycarbosilane fiber, and then sintering to prepare the hollow fiber (such as CN 110117842 B and CN 108456949 B); and customizing a fiber spinning nozzle to control the morphology of the polycarbosilane fiber to prepare the hollow silicon carbide fiber (such as CN 2700346 Y). However, the above methods have the problems of high cost, high and complex preparation process requirements.

[0004] In view of the above, it is urgent to provide a low-cost and simple-process hollow silicon carbide ceramic fiber and a preparation method and application thereof. SUMMARY

[0005] The purpose of the present application is to provide a low-cost and simple-process hollow silicon carbide ceramic fiber and a preparation method and application thereof.

[0006] The above purpose is achieved by the following technical solution: a preparation method of a hollow silicon carbide ceramic fiber, comprising the following steps:

[0007] S1, melt spinning: melt an organic silicon resin in an inert atmosphere to spin a polymer fiber;

[0008] S2, crosslinking and curing: heat crosslinking and curing treatment is performed on the polymer fiber at a predetermined temperature to obtain a non-melting fiber;

[0009] S3, thermal decomposition: the non-melting fiber is subjected to thermal decomposition in an inert atmosphere at a predetermined heating rate to a predetermined temperature to generate an inorganic ceramic fiber;

[0010] S4, sintering: sintering the inorganic ceramic fiber in an inert atmosphere at a predetermined temperature at a predetermined heating rate to generate a silicon carbide-carbon ceramic composite fiber with a carbon-rich core;

[0011] S5, decarburization: oxidatively decarburizing the silicon carbide-carbon ceramic composite fiber at a predetermined temperature at a predetermined heating rate to generate a hollow-structured silicon carbide ceramic fiber.

[0012] The present application uses inexpensive silicone resin as a precursor to convert ceramic fibers, and the silicone resin is melted in an inert atmosphere to form polymer fibrils of a predetermined diameter through predetermined process conditions; the polymer is heat-crosslinked and cured at a predetermined temperature to form a three-dimensional Si-O-Si network (crosslinking degree > 85%) through condensation of side hydroxyl groups, and then the non-melting fiber is heat-decomposed in an inert atmosphere at a predetermined heating rate to a predetermined temperature, and the relevant groups are cracked and volatilized, leaving an amorphous SiOC ceramic skeleton, to generate an inorganic ceramic fiber; and then sintering treatment is performed in an inert atmosphere at a predetermined heating rate to a predetermined temperature, a carbothermal reduction reaction occurs, free carbon migrates to the core to form a carbon-rich region, and a predetermined size of β-SiC grains grow on the shell, and finally decarburization is performed, the core carbon is selectively oxidized at a predetermined temperature to form a hollow structure, the shell retains intact β-SiC crystals, and a high-crystalline silicon carbide ceramic fiber with a hollow structure is generated.

[0013] The present application uses organic silicon resin as a precursor, and through control of the spinning, non-melting, inorganic, high-temperature sintering and high-temperature post-treatment processes, a silicon carbide ceramic fiber with high crystallinity and hollow morphology is prepared, and the production cost is much lower than that of the commonly used polycarbosilane and modified precursor in the prior art. The non-melting of the polymer fibrils is completed by heat crosslinking, and then a high-crystalline silicon carbide hollow ceramic fiber is prepared by high-temperature heat treatment. The mechanical properties of the obtained ceramic fiber are good, and compared with the existing electron beam irradiation non-melting technology, the present application has the characteristics of simple process, easy operation and low manufacturing cost.

[0014] As a preferred further technical solution, the sintering conditions in step S4 are as follows: high-temperature sintering of the inorganic ceramic fiber in an inert atmosphere at 1500 ℃-1900 ℃ at a heating rate of 0.5 ℃ / min-10 ℃ / min for 1 h-3 h to obtain a silicon carbide-carbon ceramic composite fiber with a carbon-rich core, wherein the silicon carbide phase is β-SiC crystals. Sintering treatment under this condition drives the growth of β-SiC grains, the grain size is controllable, and abnormal grain growth is avoided; the fiber surface is dense and there is no structure collapse, high crystallinity is achieved while ensuring a carbon-rich core.

[0015] As preferred, a further technical solution is that the decarburization condition in step S5 is: heating to 700-1000℃ at a heating rate of 0.5-10 ℃ / min in dry air, and the holding time is 0-3 h. By setting in this way, the high-temperature oxidative decarburization treatment under this condition can remove the free carbon inside the fiber and ensure that the fiber structure does not collapse, realize precise regulation of the hollow structure, match the decarburization temperature with the carbon diffusion rate, ensure the hollow rate of the hollow structure, and the fiber wall thickness is uniform.

[0016] As preferred, a further technical solution is that the melt spinning condition in step S1 is: heating at 150-200℃ for 0.5-1 h in an inert atmosphere, and melt spinning is carried out at a spinning speed of 100-900 r / min under a pressure of 0.1-1 MPa. The spinning pressure of 0.1-1 MPa controls the melt rheological property, and the spinning speed of 100-900 r / min regulates the fiber diameter. According to this condition, continuous fibers can be obtained, the product diameter uniformity can be realized, and continuous spinning can be ensured to avoid broken filaments or filaments, and at the same time, the obtained fiber diameter is uniform and the surface is smooth.

[0017] As preferred, a further technical solution is that the cross-linking and curing condition in step S2 is: the treatment temperature is 90-250℃, and the treatment time is 2-10 h. According to this condition, the original fiber will not melt and filamentize under the subsequent thermal decomposition and high-temperature sintering conditions, and the structural integrity is ensured.

[0018] As preferred, a further technical solution is that the thermal decomposition condition in step S3 is: heating to 800-1300℃ at a heating rate of 0.5-10 ℃ / min in an inert atmosphere, and the holding time is 0-3 h. According to this condition, the thermal decomposition treatment can ensure that the fiber surface is smooth, there is no structure collapse phenomenon, and certain mechanical properties are maintained.

[0019] As preferred, a further technical solution is that the organic silicon resin is an organic silicon polymer with Si-O bond as the main chain and groups including methyl and phenyl as side groups.

[0020] The organic silicon resin (such as methyl phenyl silicon resin, etc.) with methyl (-CH3) and phenyl (-C6H5) groups as side groups is selected. The methyl provides a high carbon residue rate (free carbon generated after cracking), and the phenyl enhances the thermal stability. The methyl is cracked to generate free carbon (core carbon phase source), and the phenyl inhibits high-temperature melting. By selecting this precursor, the technical problem of uneven composition caused by high-temperature disproportionation of polycarbosilane Si-C bond can be avoided.

[0021] Preferably, the inert atmosphere is nitrogen or argon with a purity of 99.99%. In this way, oxidation deterioration is prevented, premature consumption of carbon is avoided, and the inhibition of SiC lattice growth by oxygen impurities is reduced, thereby ensuring the crystallization quality.

[0022] To achieve the above object, the application further provides a hollow silicon carbide ceramic fiber, which is prepared by the preparation method of any of the above hollow silicon carbide ceramic fibers. The hollow silicon carbide ceramic fiber prepared by the application has good mechanical properties, and is more suitable for high-temperature thermal insulation materials and catalytic adsorption materials than the dense silicon carbide fiber in the prior art.

[0023] To achieve the above object, the application further provides an application of the hollow silicon carbide ceramic fiber, which is applied to the field of high-temperature thermal insulation materials and catalytic adsorption materials.

[0024] Compared with the prior art, the application has the following technical advantages:

[0025] 1. Low cost: The inexpensive organic silicon resin is used as a precursor to convert and prepare ceramic fibers, and the production cost is much lower than that of polycarbosilane and modified precursors;

[0026] 2. Accurate structure control: By controlling the spinning, infusibility, inorganicization, high-temperature sintering and high-temperature post-processing process, and through carbon phase migration and selective decarburization, high crystallization and controllable hollow morphology are realized;

[0027] 3. Process compatibility: No special equipment (such as expensive electronic irradiation devices) is needed throughout the process, which is easy to implement, has the characteristics of simple process, convenient operation and low manufacturing cost, and is suitable for industrial production;

[0028] 4. The hollow silicon carbide ceramic fiber prepared has good mechanical properties, and is more suitable for high-temperature thermal insulation materials and catalytic adsorption materials than the dense silicon carbide fiber in the prior art.

[0029] The application utilizes the molecular structure characteristics of organic silicon resin, and solves the industry pain points of high cost and complex process by an innovative process chain of melt spinning, crosslinking, pyrolysis, sintering and selective decarburization. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application. The embodiments of the application illustrated in the drawings, and their description thereto, are presented to explain the application and are not intended to limit the application unduly.

[0031] Figure 1 A scanning electron microscope image of the hollow silicon carbide ceramic fiber prepared in Example 1 of the application;

[0032] Figure 2 The image shows the XRD pattern of the hollow silicon carbide ceramic fiber prepared in Example 1 of this invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0035] Unless otherwise specified, all medicines / reagents used are commercially available.

[0036] Example 1

[0037] The preparation of highly crystalline silicon carbide hollow ceramic fibers includes the following steps in this embodiment:

[0038] (1) 5 g of solid silicone resin (Si-O bond as the main chain, with methyl and phenyl organosilicon polymers on the side groups) was placed in the spinning drum of a melt spinning device, high-purity nitrogen gas was introduced, the air in the spinning drum was replaced at 60 °C, heated to 190 °C, kept at the temperature for 0.5 h, and melt spun at a take-up speed of 600 r / min under a pressure of 0.5 MPa to obtain polymer fibrils;

[0039] (2) The polymer fiber was placed in a quartz tube furnace, heated to 120°C, and kept at that temperature for 3 hours to obtain non-melting fiber;

[0040] (3) Place the non-melting fiber in a quartz tube furnace, evacuate it, and introduce high-purity nitrogen to replace the air in the quartz tube furnace three times. Heat it to 1100 ℃ at a heating rate of 50 ℃ / h and keep it at this temperature for 1 h to obtain inorganic ceramic fiber.

[0041] (4) The inorganic ceramic fiber was placed in a graphite furnace, the vacuum was drawn, and high-purity nitrogen was introduced to replace the air in the graphite furnace three times. The temperature was raised to 1900 ℃ at a rate of 60 ℃ / h, and the temperature was kept at this temperature for 1 h to obtain silicon carbide-carbon ceramic composite fiber.

[0042] (5) The silicon carbide-carbon ceramic composite fiber was placed in a muffle furnace and heated to 800°C at a heating rate of 5°C / min. The temperature was then maintained at this temperature for 1 h to obtain silicon carbide ceramic fiber with a highly crystalline hollow structure.

[0043] The scanning electron microscope image of the hollow silicon carbide ceramic fiber obtained in this embodiment is shown below. Figure 1 As shown, the hollow silicon carbide ceramic fiber, characterized by scanning electron microscopy, exhibits a hollow morphology, composed of silicon carbide grains with a grain size greater than 200 nm. Figure 2 As shown, XRD characterization revealed that the fiber phase was β-SiC, and the oxygen content was less than 1% as determined by an oxygen and nitrogen analyzer.

[0044] Example 2

[0045] (1) 5 g of solid silicone resin (Si-O bond as the main chain, with methyl and phenyl organosilicon polymers on the side groups) was placed in the spinning drum of a melt spinning device, high-purity nitrogen was introduced, the air was replaced at 60 °C, the temperature was raised to 190 °C and kept for 0.5 h, and melt spinning was carried out at a take-up speed of 600 r / min under a pressure of 0.5 MPa to obtain polymer fibrils;

[0046] (2) The polymer fiber was placed in a quartz tube furnace, heated to 150 °C, and kept at that temperature for 1 h to obtain non-melting fiber;

[0047] (3) Place the non-melting fiber in a quartz tube furnace, evacuate, introduce high-purity nitrogen to replace the air three times, heat to 1100 ℃ at a heating rate of 50℃ / h, and keep it at this temperature for 1 h to obtain inorganic ceramic fiber.

[0048] (4) The inorganic ceramic fiber was placed in a graphite furnace, vacuumed, and high-purity nitrogen was introduced to replace the air three times. The temperature was raised to 1900 ℃ at a rate of 60℃ / h and kept at this temperature for 1 h to obtain silicon carbide-carbon ceramic composite fiber.

[0049] (5) Place the silicon carbide-carbon ceramic composite fiber in a muffle furnace and heat it to 800℃ at a heating rate of 5℃ / min. Then keep it at this temperature for 1 h to obtain highly crystalline silicon carbide hollow ceramic fiber.

[0050] The hollow silicon carbide ceramic fiber obtained in this embodiment was characterized by scanning electron microscopy. Its morphology is hollow, composed of silicon carbide grains with a grain size greater than 200 nm. XRD characterization showed the fiber phase to be β-SiC. Oxygen content was measured using an oxygen-nitrogen analyzer and found to be less than 1%. The characterization results are basically the same as those in Embodiment 1, and no additional figures are provided.

[0051] Example 3

[0052] (1) 5 g of solid silicone resin (Si-O bond as the main chain, with methyl and phenyl organosilicon polymers on the side groups) was placed in the spinning drum of a melt spinning device, high-purity nitrogen was introduced, the air was replaced at 60 °C, the temperature was raised to 190 °C and kept for 0.5 h, and melt spinning was carried out at a take-up speed of 600 r / min under a pressure of 0.5 MPa to obtain polymer fibrils;

[0053] (2) The polymer fiber was placed in a quartz tube furnace, heated to 180 °C, and kept at that temperature for 1 h to obtain non-melting fiber;

[0054] (3) Place the non-melting fiber in a quartz tube furnace, evacuate, introduce high-purity nitrogen to replace the air three times, heat to 1100 ℃ at a heating rate of 50℃ / h, and keep it at this temperature for 1 h to obtain inorganic ceramic fiber.

[0055] (4) The inorganic ceramic fiber was placed in a graphite furnace, vacuumed, and high-purity nitrogen was introduced to replace the air three times. The temperature was raised to 1900 ℃ at a rate of 60℃ / h and kept at this temperature for 1 h to obtain silicon carbide-carbon ceramic composite fiber.

[0056] (5) Place the silicon carbide-carbon ceramic composite fiber in a muffle furnace and heat it to 800℃ at a heating rate of 5℃ / min. Then keep it at this temperature for 1 h to obtain highly crystalline silicon carbide hollow ceramic fiber.

[0057] The hollow silicon carbide ceramic fiber obtained in this embodiment was characterized by scanning electron microscopy. Its morphology is hollow, composed of silicon carbide grains with a grain size greater than 200 nm. XRD characterization showed the fiber phase to be β-SiC. Oxygen content was measured using an oxygen-nitrogen analyzer and found to be less than 1%. The characterization results are basically the same as those in Embodiment 1, and no additional figures are provided.

[0058] Example 4

[0059] (1) 5 g of solid silicone resin (Si-O bond as the main chain, with methyl and phenyl organosilicon polymers on the side groups) was placed in the spinning drum of a melt spinning device, high-purity nitrogen was introduced, the air was replaced at 60 °C, heated to 200 °C, kept at the temperature for 0.5 h, and melt spun at a take-up speed of 300 r / min under a pressure of 1 MPa to obtain polymer fibrils;

[0060] (2) The polymer fiber was placed in a quartz tube furnace, heated to 90 °C, and kept at that temperature for 10 h to obtain non-melting fiber;

[0061] (3) Place the non-melting fiber in a quartz tube furnace, evacuate, introduce high-purity nitrogen to replace the air three times, heat to 800 ℃ at a heating rate of 30℃ / h, and keep it at this temperature for 3h to obtain inorganic ceramic fiber.

[0062] (4) The inorganic ceramic fiber was placed in a graphite furnace, vacuumed, and high-purity nitrogen was introduced to replace the air three times. The temperature was raised to 1500 ℃ at a rate of 60℃ / h and kept at this temperature for 3 h to obtain silicon carbide-carbon ceramic composite fiber.

[0063] (5) Place the silicon carbide-carbon ceramic composite fiber in a muffle furnace and heat it to 700℃ at a heating rate of 10℃ / min. Then, keep it at this temperature for 3 hours to obtain highly crystalline silicon carbide hollow ceramic fiber.

[0064] The hollow silicon carbide ceramic fiber obtained in this embodiment was characterized by scanning electron microscopy. Its morphology is hollow, composed of silicon carbide grains with a grain size greater than 200 nm. XRD characterization showed the fiber phase to be β-SiC. Oxygen content was measured using an oxygen-nitrogen analyzer and found to be less than 1%. The characterization results are basically the same as those in Embodiment 1, and no additional figures are provided.

[0065] Example 5

[0066] (1) 5 g of solid silicone resin (Si-O bond as the main chain, with methyl and phenyl organosilicon polymers on the side groups) was placed in the spinning drum of a melt spinning device, high-purity nitrogen was introduced, the air was replaced at 60 °C, the temperature was raised to 200 °C and kept for 0.5 h, and melt spinning was carried out at a take-up speed of 900 r / min under a pressure of 0.1 MPa to obtain polymer fibrils;

[0067] (2) The polymer fiber was placed in a quartz tube furnace, heated to 250 °C, and kept at that temperature for 2 h to obtain non-melting fiber;

[0068] (3) Place the non-melting fiber in a quartz tube furnace, evacuate, introduce high-purity nitrogen to replace the air three times, heat to 1100 ℃ at a heating rate of 600℃ / h, and keep it at this temperature for 1 h to obtain inorganic ceramic fiber.

[0069] (4) The inorganic ceramic fiber was placed in a graphite furnace, vacuumed, and high-purity nitrogen was introduced to replace the air three times. The temperature was raised to 1900 ℃ at a rate of 30℃ / h and kept at this temperature for 1 h to obtain silicon carbide-carbon ceramic composite fiber.

[0070] (5) Place the silicon carbide-carbon ceramic composite fiber in a muffle furnace and heat it to 1000 ℃ at a heating rate of 10 ℃ / min. Then, keep it at this temperature for 1 h to obtain highly crystalline silicon carbide hollow ceramic fiber.

[0071] The hollow silicon carbide ceramic fiber obtained in this embodiment was characterized by scanning electron microscopy. Its morphology is hollow, composed of silicon carbide grains with a grain size greater than 200 nm. XRD characterization showed the fiber phase to be β-SiC. Oxygen content was measured using an oxygen-nitrogen analyzer and found to be less than 5%. The characterization results are basically the same as those in Embodiment 1, and no additional figures are provided.

[0072] Example 6

[0073] (1) 5 g of solid silicone resin (Si-O bond as the main chain, with methyl and phenyl organosilicon polymers on the side groups) was placed in the spinning drum of a melt spinning device, high-purity nitrogen was introduced, the air was replaced at 60 °C, the temperature was raised to 150 °C and kept for 0.5 h, and melt spinning was carried out at a take-up speed of 100 r / min under a pressure of 0.5 MPa to obtain polymer fibrils;

[0074] (2) The polymer fiber was placed in a quartz tube furnace, heated to 250 °C, and kept at that temperature for 1 h to obtain non-melting fiber;

[0075] (3) Place the non-melting fiber in a quartz tube furnace, evacuate, introduce high-purity nitrogen to replace the air three times, heat to 1100 ℃ at a heating rate of 50℃ / h, and keep it at this temperature for 1 h to obtain inorganic ceramic fiber.

[0076] (4) The inorganic ceramic fiber was placed in a graphite furnace, vacuumed, and high-purity nitrogen was introduced to replace the air three times. The temperature was raised to 1900 ℃ at a rate of 60℃ / h and kept at this temperature for 1 h to obtain silicon carbide-carbon ceramic composite fiber.

[0077] (5) Place the silicon carbide-carbon ceramic composite fiber in a muffle furnace and heat it to 1000℃ at a heating rate of 5℃ / min. Then keep it at this temperature for 1 h to obtain highly crystalline silicon carbide hollow ceramic fiber.

[0078] The hollow silicon carbide ceramic fiber obtained in this embodiment was characterized by scanning electron microscopy. Its morphology is hollow, composed of silicon carbide grains with a grain size greater than 200 nm. XRD characterization showed the fiber phase to be β-SiC. Oxygen content was measured using an oxygen-nitrogen analyzer and found to be less than 5%. The characterization results are basically the same as those in Embodiment 1, and no additional figures are provided.

[0079] For those skilled in the art, various improvements and modifications can be made without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A method for preparing hollow silicon carbide ceramic fibers, characterized in that, Includes the following steps: S1, Melt spinning: The silicone resin is melted in an inert atmosphere and spun to generate polymer fibrils. The silicone resin is a silicone polymer with Si-O bonds as the main chain and side groups including methyl and phenyl groups. S2, Crosslinking and Curing: The polymer fibrils are subjected to thermal crosslinking and curing treatment at a predetermined temperature for 1 h to 10 h to obtain infusible fibers; S3, thermal decomposition: In an inert atmosphere, the non-melting fibers are thermally decomposed at a predetermined temperature by heating at a predetermined heating rate for 1 h to 3 h, generating inorganic ceramic fibers. S4, Sintering: In an inert atmosphere, inorganic ceramic fibers are sintered at high temperature to 1500 ℃~1900 ℃ at a rate of 0.5 ℃ / min ~10 ℃ / min and held for 1 h~3 h. Free carbon migrates to the core to form a carbon-rich region, and β-SiC grains of a predetermined size grow on the outer shell, resulting in silicon carbide-carbon ceramic composite fibers with a carbon-rich core, wherein the silicon carbide phase is β-SiC crystals. S5, Decarburization: In dry air, the silicon carbide-carbon ceramic composite fiber is heated to 700 ℃~1000 ℃ at a heating rate of 0.5 ℃ / min ~10 ℃ / min and held for 1~3 h to perform oxidative decarburization treatment, generating hollow silicon carbide ceramic fiber.

2. The method for preparing hollow silicon carbide ceramic fibers according to claim 1, characterized in that, The melt spinning conditions in step S1 are as follows: in an inert atmosphere, heating at a temperature of 150 ℃ to 200 ℃ for 0.5 h to 1 h, and melt spinning at a take-up speed of 100 r / min to 900 r / min under a pressure of 0.1 MPa to 1 MPa.

3. The method for preparing hollow silicon carbide ceramic fibers according to claim 2, characterized in that, The crosslinking and curing conditions in step S2 are: a processing temperature of 90 ℃ to 250 ℃.

4. The method for preparing hollow silicon carbide ceramic fibers according to claim 3, characterized in that, The thermal decomposition conditions in step S3 are as follows: in an inert atmosphere, the temperature is increased to 800 ℃~1300 ℃ at a heating rate of 0.5 ℃ / min ~ 10 ℃ / min.

5. The method for preparing hollow silicon carbide ceramic fibers according to claim 1, characterized in that, The inert atmosphere is nitrogen or argon with a purity of ≥99.99%.

6. A hollow silicon carbide ceramic fiber, characterized in that, It is prepared by the method for preparing hollow silicon carbide ceramic fibers according to any one of claims 1 to 5.

7. An application of hollow silicon carbide ceramic fiber, characterized in that, The hollow silicon carbide ceramic fiber described in claim 6 is applied to the fields of high-temperature thermal insulation materials and catalytic adsorption materials.

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