A pitch-based carbon fiber composite material, a method for preparing the same, and an application thereof

Abstract

This invention relates to a pitch-based carbon fiber composite material, its preparation method, and its application. The composite material comprises a resin matrix, carbon nanofiber membranes (2), and pitch-based carbon fiber layers (1). Multiple layers of the carbon nanofiber membranes (2) and pitch-based carbon fiber layers (1) are stacked alternately. The resin matrix coats the multiple layers of carbon nanofiber membranes (2) and pitch-based carbon fiber layers (1) and fills the gaps between each layer. Adjacent carbon nanofiber membranes (2) and pitch-based carbon fiber layers (1) are filled with resin matrix. Compared to existing technologies, this invention uses highly thermally conductive mesophase pitch-based carbon fibers as reinforcing fibers and inserts inorganic thermally conductive nanoparticle-doped carbon nanofiber membranes between the reinforcing resin matrix composite layers to prepare a highly thermally conductive composite material.

Description

Technical Field

[0001] This invention relates to the field of composite materials, and in particular to a pitch-based carbon fiber composite material, its preparation method, and its application. Background Technology

[0002] Traditional carbon fiber reinforced resin (CFRP) composites have low thermal conductivity, making it difficult to dissipate heat generated during use and affecting their applications. Currently, four methods exist to improve the thermal conductivity of CFRP composites: CFs surface modification, CFs orientation treatment, addition of thermally conductive fillers, and construction of three-dimensional continuous thermally conductive channels. Among these, adding high thermal conductivity fillers to the resin matrix is ​​currently the most commonly used method to improve the thermal conductivity of CFRP composites.

[0003] Chinese patent CN115286823A discloses a high thermal conductivity and electromagnetic shielding polyimide-based co-carbonized carbon fiber composite material and its preparation method. The method involves co-spinning polyimide felt with two-dimensional nanofillers such as graphene, followed by three-dimensional needle punching, roll-to-roll two-dimensional nanofiller impregnation, co-carbonization, and graphitization processes to obtain a co-carbonized carbon fiber reinforcement. This is then impregnated with a high-performance resin, resulting in a composite material with excellent thermal conductivity, ultra-high electromagnetic shielding performance, and superior mechanical properties. Chinese patent CN112552648A discloses a three-dimensional ordered and controllable carbon fiber thermally conductive composite material and its preparation method. This method involves non-covalent modification of carbon fibers, maintaining their inherent properties while reducing the contact thermal resistance between carbon fibers and the interfacial thermal resistance between carbon fibers and the polymer matrix, thus improving the interfacial bonding force between the carbon fibers and the polymer matrix. Simultaneously, an ice-template method is used to create a three-dimensional ordered skeleton, controlling the orientation of the carbon fibers to provide pathways for phonon transmission, thereby improving the thermal conductivity of the composite material with a low carbon fiber load. Chinese patent CN111393795A discloses a three-dimensional thermally conductive and insulating epoxy resin composite material and its preparation method. By constructing a three-dimensional thermally conductive network, the final epoxy composite material exhibits excellent thermal conductivity and electrical insulation properties. Chinese patent CN110228248A discloses a high thermal conductivity anisotropic polymer-based composite material and its preparation method. A thermally conductive filler dispersion solution is drawn into a syringe and subjected to high-voltage electrostatic sputtering. Through electrostatic force and hydrogen bonding, the filler adheres to polymer nanofibers, forming a network structure with mutually contacting, oriented fillers. After lamination, the composite material is obtained through cold compression and hot pressing.

[0004] The above patents all improve the thermal conductivity of CFRP composites by adding high thermal conductivity fillers to the resin matrix. However, in addition to poor thermal conductivity, the composites obtained by this method are prone to delamination damage. Adding high thermal conductivity fillers such as graphene and carbon nanotubes to the resin matrix can effectively improve the thermal conductivity of the composite material. However, adding fillers will reduce the toughness of the composite material and easily cause delamination damage. At the same time, the viscosity of the matrix resin increases after adding thermally conductive fillers, making it difficult to fully impregnate the carbon fibers, which will affect the molding process and mechanical properties of the composite material.

[0005] Therefore, improving the resistance to delamination damage has always been a research hotspot. Currently, the main methods for improving the delamination damage of composite materials include matrix resin reinforcement, Z-axis reinforcement technology, and interlaminar reinforcement. Among them, interlaminar reinforcement has the advantages of not affecting the composite material molding process and not damaging carbon fibers. The reinforcement is mainly divided into three types: organic / inorganic particles, resin films, and resin fibers.

[0006] Chinese patent CN112476846A discloses a high thermal conductivity carbon fiber prepreg and its preparation method, which prepares a carbon fiber prepreg loaded with a nanofiber membrane by double hot-pressing and impregnating the fiber yarn bundles in a staggered arrangement. Chinese patent CN101007443A discloses a method for preparing nanofiber-toughened carbon fiber resin-based composite materials. This patent utilizes the good electrical conductivity of carbon fiber, using a carbon fiber / resin matrix preform as a receiver for electrospinning, directly spinning nanofibers onto the preform, and conveniently laying nanofibers between the layers of the carbon fiber resin-based composite material through layering. Chinese patent CN102794952A discloses a method for preparing a simultaneously reinforced and toughened composite material with highly oriented hybrid nanofibers. This method utilizes a hybrid nanofiber membrane with highly oriented MWNTs to simultaneously reinforce and toughen CFRP composite materials, truly solving the problem of reinforcing and toughening carbon fiber composite materials from the perspective of interlayer reinforcement and toughening.

[0007] The three interlayer reinforcement methods—resin particles, films, and fibers—all involve adding thermoplastic resins between the composite layers to improve interlayer toughness. However, resins have low heat transfer efficiency and poor thermal conductivity, and their addition increases the interlayer thermal resistance, leading to a decrease in the composite's thermal conductivity. Furthermore, thermoplastic resins have lower modulus and heat resistance than thermosetting matrix resins; therefore, adding thermoplastic resins between layers also reduces the composite's rigidity and heat resistance. Summary of the Invention

[0008] The purpose of this invention is to provide a pitch-based carbon fiber composite material, its preparation method, and its application. This invention uses highly thermally conductive mesophase pitch-based carbon fiber as the reinforcing fiber, and inserts an inorganic thermally conductive nanoparticle-doped carbon nanofiber membrane into the interlayer of the reinforcing resin-based composite material to prepare a highly thermally conductive composite material.

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] A pitch-based carbon fiber composite material includes a resin matrix, carbon nanofiber membranes, and pitch-based carbon fiber layers, wherein multiple layers of the carbon nanofiber membranes and pitch-based carbon fiber layers are stacked alternately in sequence, the resin matrix covers multiple layers of carbon nanofiber membranes and pitch-based carbon fiber layers and fills the gaps within each layer of carbon nanofiber membranes and pitch-based carbon fiber layers, and the resin matrix fills the gaps between adjacent carbon nanofiber membranes and pitch-based carbon fiber layers.

[0011] Furthermore, each of the pitch-based carbon fiber layers consists of unidirectionally arranged continuous carbon fibers.

[0012] Furthermore, the thickness of each pitch-based carbon fiber layer is 0.1-0.25 mm.

[0013] Furthermore, the thickness of each carbon nanofiber membrane layer is 0.01-0.1 mm.

[0014] This invention also provides a method for preparing pitch-based carbon fiber composite materials, the specific steps of which are as follows:

[0015] (1) Dissolve nanoparticles and polyacrylonitrile in an organic solvent to prepare a nanofiber spinning solution;

[0016] (2) The nanofiber spinning solution obtained in step (1) is used to prepare a carbon nanofiber membrane precursor by electrospinning technology;

[0017] (3) The carbon nanofiber membrane precursor obtained in step (2) is subjected to pre-oxidation and high-temperature carbonization heat treatment to obtain carbon nanofiber membrane.

[0018] (4) The carbon nanofiber membrane obtained in step (3) is alternately laid with pitch-based carbon fiber prepreg and hot-pressed to form a carbon nanofiber membrane layer, and the pitch-based carbon fiber prepreg forms a pitch-based carbon fiber layer and a resin matrix. After the resin matrix encapsulates multiple carbon nanofiber membrane layers and pitch-based carbon fiber layers, a pitch-based carbon fiber composite material is obtained.

[0019] Further, in step (1), the mass ratio of the nanoparticles, polyacrylonitrile, and organic solvent is 1:1 to 2:17 to 18.

[0020] Further, in step (1), the nanoparticles are selected from any one of graphene, boron nitride, aluminum nitride, silicon carbide, aluminum oxide, zinc oxide, fullerene, or carbon nanotubes.

[0021] Further, in step (1), the organic solvent is selected from any one or more of NMP, DMSO, DMAC, and DMF.

[0022] Further, in step (2), the electrospinning temperature is 20-30℃, the relative humidity is 23-30%, the winding speed (used to control the thickness) is 1-60mm / min, and the voltage is 25-80kV.

[0023] Further, in step (3), the temperature range of the pre-oxidation process is 200-300℃, and the process of the pre-oxidation process is as follows: after holding at 200-210℃ for 15-25 minutes, the temperature is increased to the set temperature of 280-300℃ at a heating rate of 2-4℃ / min, and then held for 0.5-1.5 hours.

[0024] Furthermore, in step (3), the maximum temperature range of the high-temperature carbonization treatment is 850-1000℃.

[0025] Further, in step (3), the process of the high-temperature carbonization treatment is as follows: first, the temperature is increased from room temperature (24°C) to 200°C at a heating rate of 10°C / min, then the temperature is increased from 200°C to 600°C at a heating rate of 2°C / min, and finally the temperature is increased from 600°C to 950°C at a heating rate of 5°C / min, and then the furnace is naturally cooled.

[0026] Further, in step (4), the preparation method of the pitch-based carbon fiber prepreg is as follows: the pitch-based carbon fiber prepreg is made by impregnating the resin matrix in pitch-based carbon fiber.

[0027] Furthermore, the resin matrix is ​​an epoxy resin;

[0028] The pitch-based carbon fiber is selected from mesophase pitch-based carbon fiber or isotropic pitch-based carbon fiber.

[0029] Furthermore, in step (4), the pitch-based carbon fiber prepreg is a composite material made of pitch-based carbon fiber, resin matrix, release paper and other materials, processed by coating, hot pressing, cooling, film covering and winding processes.

[0030] Furthermore, in step (4), the method of alternately laying the carbon nanofiber membrane and pitch-based carbon fiber prepreg is as follows:

[0031] S1. Lay a layer of polyimide film flat on the stainless steel plate;

[0032] S2. Place a stainless steel mold (vacuum mold) on the polyimide film;

[0033] S3. The pitch-based carbon fiber prepreg and carbon nanofiber membrane are alternately placed in a stainless steel mold, with the bottom and top layers being pitch-based carbon fiber prepreg.

[0034] S4. Place the positive mold in to obtain the assembled mold;

[0035] S5. The assembled mold is placed into a flat vulcanizing machine for hot pressing and molding. After demolding, asphalt-based carbon fiber composite material is obtained.

[0036] Further, in step (4), the hot pressing process is as follows:

[0037] After placing the mold, heat the material from room temperature (24℃) to 100℃ and hot-press it at 2.5MPa for 30 minutes; then press it to 5MPa and hold it for 1 hour; heat the material to 120℃ and hot-press it at 20MPa for 1 hour; then heat the material to 150℃ and hot-press it at 20MPa for 1 hour; then heat the material to 180℃ and hot-press it at 20MPa for 2 hours; finally, turn off the heating and allow it to cool naturally while maintaining the pressure at 15MPa. After cooling to room temperature, remove the mold and demold.

[0038] Furthermore, the present invention also provides an application of pitch-based carbon fiber composite material, which is used in the aerospace, industrial, sports, or electronic fields.

[0039] Furthermore, the asphalt-based carbon fiber composite material is used in the manufacture of satellite components, space optical structural components, drive shafts, vehicle structural components, building materials, sports equipment (fishing rods, bicycle frames, rackets), large-scale integrated circuits, mobile phone cases, large heat sinks, computer cases, or cooling components for high-power lasers.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] This invention improves both the thermal conductivity and mechanical properties of composite materials. The interlaminar region of a composite material is composed only of the matrix resin, resulting in the worst thermal conductivity and mechanical properties within the composite, thus reducing the overall thermal conductivity and mechanical properties. Carbon nanofibers are high-porosity fiber materials with nanoscale effects. After being doped with inorganic thermally conductive nanoparticles such as graphene and carbon nanotubes, they possess high thermal conductivity, high strength, and high modulus. They can be obtained by further carbonizing resin-based nanofibers. Inserting these nanofibers into the interlaminar region of the composite material not only constructs a thermally conductive network, improving the thermal conductivity of the interlaminar region, but also strengthens and stiffens the interlaminar region by utilizing the high strength and high modulus of carbon nanofibers, as well as their fiber bridging and pull-out reinforcement mechanisms, thereby improving the mechanical properties of the interlaminar region. This simultaneously improves both the thermal conductivity and mechanical properties of the composite material.

[0042] Unlike current methods that improve the thermal conductivity of composite materials by adding thermally conductive fillers to the matrix resin, this invention nanofiberizes the thermally conductive filler and precisely targets it in the interlayer region where thermal conductivity is weakest. This reduces interlayer thermal resistance, effectively improving the thermal conductivity of the composite material without affecting the viscosity of the matrix resin or its wetting effect on the carbon fibers. Furthermore, unlike current methods that use thermoplastic resin nanofiber intercalation to toughen composite materials, the thermally conductive particle-doped carbon nanofibers possess high temperature resistance, high strength, and high modulus. When intercalated into the interlayer of the composite material, they improve interlayer heat resistance, strength, and rigidity, thereby enhancing the composite material's heat resistance and compressive strength. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the layered structure of the pitch-based carbon fiber composite material of the present invention.

[0044] The reference numerals are as follows: 1. Pitch-based carbon fiber layer; 2. Carbon nanofiber membrane layer. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0046] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0047] Example 1

[0048] This embodiment provides a method for preparing graphene / polyacrylonitrile nanofiber composite materials, the specific steps of which are as follows:

[0049] (1) Take a beaker and add a certain amount of polyacrylonitrile and organic solvent NMP. After stirring and mixing thoroughly, add nano-particle graphene. The above components are 5wt% graphene, 10wt% polyacrylonitrile, and 85wt% organic solvent NMP.

[0050] (2) Seal the mouth of the beaker after adding the reagent with a plastic film, and make a hole in the center of the plastic film and insert an ultrasonic rod to disperse the graphene; put the beaker into a water cooling device to disperse the heat generated during the ultrasonic process and avoid the evaporation of organic solvents; ultrasonicate for 30 minutes at a frequency of 20KHz and a power of 1200w to obtain a nanofiber spinning solution.

[0051] (3) Carbon nanofiber membrane precursors were prepared by electrospinning the nanofiber spinning solution;

[0052] Electrospinning is performed using an electrospinning machine (needle-free equipment). The specific operating procedure is as follows: Install and adjust the collecting substrate (adhere the substrate to a paper roll, such as tearable adhesive tape), maintaining uniform tension; mark the required positions on the substrate and adjust the height of the collecting electrodes; install the liquid carrier tank and metal inserts, adjust the tension and position of the electrode wires, and place the high-voltage protection cover; pour the nanofiber spinning solution into the liquid carrier tank, close the equipment door, set the moving speed of the liquid carrier tank, turn on the power switch, gradually increase the voltage, and set a suitable substrate speed; the electrospinning temperature is 24℃, the relative humidity is 27%, the winding speed is 20mm / min, and the voltage is 60kV.

[0053] (4) Place the carbon nanofiber membrane precursor in an electric heating drying oven and dry it at 70°C for 12 hours for later use; then cut the dried carbon nanofiber membrane precursor into appropriate sizes, place it in a graphite jar, and put it in a vacuum tube high-temperature sintering furnace for pre-oxidation treatment. Raise the temperature of the high-temperature sintering furnace from room temperature to 200°C and hold it for 20 minutes, then raise the temperature to the set temperature of 280°C at a rate of 3°C / min and hold it for 1 hour for pre-oxidation.

[0054] (5) The pre-oxidized carbon nanofiber membrane precursor is placed in a high-temperature furnace for carbonization. The heating process is as follows: first, the temperature is increased from room temperature (24℃) to 200℃ at a heating rate of 10℃ / min, then from 200℃ to 600℃ at a heating rate of 2℃ / min, and finally from 600℃ to 950℃ at a heating rate of 5℃ / min. After that, the furnace is naturally cooled to obtain the carbon nanofiber membrane.

[0055] (6) Carbon nanofiber membranes and pitch-based carbon fiber prepregs were alternately placed into a stainless steel mold for hot pressing. The hot pressing process was as follows: the temperature was raised from room temperature (24℃) to 100℃ and hot-pressed at 2.5MPa for 30 minutes, then the pressure was increased to 5MPa and held for 1 hour, the temperature was raised to 120℃ and hot-pressed at 20MPa for 1 hour, then the temperature was raised to 150℃ and hot-pressed at 20MPa for 1 hour, and finally the temperature was raised to 180℃ and hot-pressed at 20MPa for 2 hours. After the process was completed, the heating was turned off and the material was allowed to cool naturally while maintaining the pressure at 15MPa. After cooling to room temperature, the material was removed from the mold to obtain a graphene / polyacrylonitrile nanofiber composite material.

[0056] In the graphene / polyacrylonitrile nanofiber composite material, the carbon nanofiber membrane layer 2 has 23 layers, the pitch-based carbon fiber layer 1 has 24 layers, the pitch-based carbon fiber layer 1 has 60 columns of carbon fibers, and the width of each column of carbon fiber bundle is 3 mm.

[0057] This embodiment prepares a high-strength, high-thermal-conductivity composite material by inserting an inorganic thermally conductive nanoparticle (graphene)-doped carbon nanofiber membrane between the layers of its reinforced resin-based composite material.

[0058] Example 2

[0059] This embodiment provides a method for preparing a carbon nanotube / polyacrylonitrile nanofiber composite material. Except that the nanoparticles in step (1) are carbon nanotubes, the rest are the same as the steps in Example 1.

[0060] In the carbon nanotube / polyacrylonitrile nanofiber composite material, the carbon nanofiber membrane layer 2 has 17 layers, the pitch-based carbon fiber layer 1 has 18 layers, the pitch-based carbon fiber layer 1 has 60 columns of carbon fibers, and the width of each column of carbon fiber bundle is 3 mm.

[0061] Example 3

[0062] This embodiment provides a method for preparing boron nitride / polyacrylonitrile nanofiber composite material. Except that the nanoparticles in step (1) are boron nitride, the rest are the same as the steps in Example 1.

[0063] In the boron nitride / polyacrylonitrile nanofiber composite material, the carbon nanofiber membrane layer 2 has 11 layers, the pitch-based carbon fiber layer 1 has 12 layers, the pitch-based carbon fiber layer 1 has 60 columns of carbon fibers, and the width of each column of carbon fiber bundle is 3 mm.

[0064] Comparative Example 1

[0065] This comparative example provides a method for preparing a carbon fiber composite material, wherein no carbon nanofiber membrane is added to the composite material. The specific steps are as follows:

[0066] Multilayer pitch-based carbon fiber prepreg was placed in a stainless steel mold and hot-pressed. The hot-pressing process was as follows: the temperature was raised from room temperature (24℃) to 100℃ and hot-pressed at 2.5 MPa for 30 minutes; the pressure was increased to 5 MPa and held for 1 hour; the temperature was raised to 120℃ and hot-pressed at 20 MPa for 1 hour; the temperature was raised to 150℃ and hot-pressed at 20 MPa for 1 hour; the temperature was raised to 180℃ and hot-pressed at 20 MPa for 2 hours. After the process, the heating was turned off and the material was allowed to cool naturally while maintaining a pressure of 15 MPa. After cooling to room temperature, the material was removed from the mold to obtain the carbon fiber composite material.

[0067] Performance testing

[0068] The performance of the graphene / polyacrylonitrile nanofiber composite material prepared in Example 1, the carbon nanotube / polyacrylonitrile nanofiber composite material prepared in Example 2, the boron nitride / polyacrylonitrile nanofiber composite material prepared in Example 3, and the carbon fiber composite material prepared in Comparative Example 1 were tested respectively. The test results are shown in Table 1.

[0069] Table 1 Performance results of different composite materials

[0070]

[0071] As shown in Table 1, the thermal conductivity of the carbon fiber composite material without the addition of carbon nanofiber membrane in Comparative Example 1 is 230 W / m·K, and the compressive strength is 220 MPa.

[0072] In Example 2, the composite material prepared by using carbon nanotube / polyacrylonitrile nanofiber membrane has a thermal conductivity of 260 W / m·K and a compressive strength of 260 MPa, which represents an increase of 13.0% and 18.2% in thermal conductivity and compressive strength, respectively.

[0073] In Example 1, the composite material prepared by using a graphene / polyacrylonitrile nanofiber membrane had a thermal conductivity of 255 W / m·K and a compressive strength of 248 MPa, which increased by 10.9% and 12.7%, respectively.

[0074] In Example 3, the composite material prepared by using boron nitride / polyacrylonitrile nanofiber membrane had a thermal conductivity of 238 W / m·K and a compressive strength of 245 MPa, which increased by 3.5% and 11.4%, respectively.

[0075] Therefore, adding carbon nanofiber membranes to carbon fiber composites can not only improve the thermal conductivity of the material, but also enhance its mechanical properties.

[0076] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing a pitch-based carbon fiber composite material, characterized in that, The specific steps are as follows: (1) Dissolve inorganic thermally conductive nanoparticles and polyacrylonitrile in an organic solvent to prepare a nanofiber spinning solution; (2) The nanofiber spinning solution obtained in step (1) is used to prepare a carbon nanofiber membrane precursor by electrospinning technology; (3) The carbon nanofiber membrane precursor obtained in step (2) is subjected to pre-oxidation and high-temperature carbonization heat treatment to obtain carbon nanofiber membrane. (4) The carbon nanofiber membrane obtained in step (3) is alternately laid with pitch-based carbon fiber prepreg and hot-pressed to form a carbon nanofiber membrane layer (2), and the pitch-based carbon fiber prepreg forms a pitch-based carbon fiber layer (1) and a resin matrix. The resin matrix encapsulates multiple layers of carbon nanofiber membrane layer (2) and pitch-based carbon fiber layer (1) to obtain a pitch-based carbon fiber composite material. The pitch-based carbon fiber composite material includes a resin matrix, a carbon nanofiber membrane (2) and a pitch-based carbon fiber layer (1). Multiple layers of the carbon nanofiber membrane (2) and the pitch-based carbon fiber layer (1) are stacked alternately in sequence. The resin matrix covers multiple layers of carbon nanofiber membrane (2) and pitch-based carbon fiber layer (1) and fills the gaps in each layer of carbon nanofiber membrane (2) and pitch-based carbon fiber layer (1). The resin matrix fills the gaps between adjacent carbon nanofiber membrane (2) and pitch-based carbon fiber layer (1).

2. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, Each of the pitch-based carbon fiber layers (1) consists of unidirectionally arranged continuous carbon fibers.

3. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, The thickness of each pitch-based carbon fiber layer (1) is 0.1-0.25 mm; The thickness of each carbon nanofiber membrane layer (2) is 0.01-0.1 mm.

4. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, In step (1), the mass ratio of the inorganic thermally conductive nanoparticles, polyacrylonitrile, and organic solvent is 1:1~2:17~18; The inorganic thermally conductive nanoparticles are selected from any one of graphene, boron nitride, aluminum nitride, silicon carbide, aluminum oxide, zinc oxide, fullerene, or carbon nanotubes. The organic solvent is selected from any one or more of NMP, DMSO, DMAC, and DMF.

5. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, In step (2), the electrospinning temperature is 20~30 ℃, the relative humidity is 23-30%, the winding speed is 1-60 mm / min, and the voltage is 25-80 kV.

6. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, In step (3), the temperature range of the pre-oxidation process is 200-300℃, and the process flow of the pre-oxidation process is as follows: after holding at 200~210℃ for 15~25min, the temperature is increased to the set temperature of 280~300℃ at a heating rate of 2~4℃ / min, and held for 0.5~1.5h. The maximum temperature range of the high-temperature carbonization heat treatment is 850-1000 ℃.

7. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, In step (4), the preparation method of the pitch-based carbon fiber prepreg is as follows: pitch-based carbon fiber prepreg is prepared by impregnating a resin matrix in pitch-based carbon fiber; The resin matrix is ​​epoxy resin; The pitch-based carbon fiber is selected from mesophase pitch-based carbon fiber or isotropic pitch-based carbon fiber.

8. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, In step (4), the method of alternately laying carbon nanofiber membrane and pitch-based carbon fiber prepreg is as follows: S1. Lay a layer of polyimide film flat on the stainless steel plate; S2. Place the female mold on the polyimide film; S3. The pitch-based carbon fiber prepreg and carbon nanofiber membrane are alternately placed in a stainless steel mold, with the bottom and top layers being pitch-based carbon fiber prepreg. S4. Place the positive mold in to obtain the assembled mold; S5. The assembled mold is placed into a flat vulcanizing machine for hot pressing and molding. After demolding, asphalt-based carbon fiber composite material is obtained.

9. The method for preparing a pitch-based carbon fiber composite material according to claim 1, characterized in that, In step (4), the hot pressing process is as follows: After placing the mold, heat the material from room temperature (24℃) to 100℃ and hot-press it at 2.5MPa for 30 minutes; then press it to 5MPa and hold it for 1 hour; heat the material to 120℃ and hot-press it at 20MPa for 1 hour; then heat the material to 150℃ and hot-press it at 20MPa for 1 hour; then heat the material to 180℃ and hot-press it at 20MPa for 2 hours; finally, turn off the heating and allow it to cool naturally while maintaining the pressure at 15MPa. After cooling to room temperature, remove the mold and demold.

10. An application of a pitch-based carbon fiber composite material, characterized in that, The pitch-based carbon fiber composite material obtained by any of the preparation methods described in claims 1-9 can be used to prepare satellite components, space optical structural components, drive shafts, vehicle structural components, building materials, sports equipment, large-scale integrated circuits, mobile phone cases, large heat sinks, computer cases, or cooling components for high-power lasers.

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