Carbon fiber composite material and preparation method thereof

Abstract

The invention relates to the technical field of preparation of carbon fiber composite materials, in particular to a carbon fiber composite material and a preparation method thereof. Comprising the following steps: S1, dipping a carbon fiber felt into a mixed solution of epoxy resin, a curing agent and absolute ethyl alcohol; s2, functional carbon fibers are evenly spread on an electrostatic flocking table top, and the carbon fiber felt obtained in the step S1 is placed above the electrostatic flocking table to be subjected to electrostatic flocking; s3, the carbon fiber felt and the carbon fiber cloth which are subjected to electrostatic flocking in the step S2 are sequentially laid layer by layer, and cold pressing is carried out; and S4, the carbon fiber felt-carbon fiber cloth composite layer obtained in the step S3 is mixed with epoxy resin and a curing agent through a vacuum bag pressing forming technology, and curing is conducted. The carbon fiber composite material prepared by the invention has efficient heat-conducting property and mechanical property, and can overcome the problems of the traditional carbon fiber felt.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon fiber composite material preparation, and particularly relates to a carbon fiber composite material and a preparation method thereof. BACKGROUND

[0002] Carbon fiber composite materials play a crucial role in reducing the weight of aerospace structures, significantly improving flight performance and fuel efficiency due to their high strength, low density, and high modulus. However, with the rapid progress of emerging technologies such as 5G communication and high-performance electronic devices, the heat dissipation problem has become a key factor restricting its further development. Therefore, traditional carbon fiber composite materials urgently need to improve their thermal conductivity while maintaining their original excellent mechanical properties.

[0003] Generally, the thermal conductivity of carbon fiber composite materials is usually enhanced by two main methods: by functionalizing the surface of carbon fibers or by incorporating thermally conductive materials into the resin. However, the use of highly corrosive chemicals or high-energy impacts in carbon fiber surface treatment often damages its ordered crystal structure, leading to a significant decrease in its mechanical properties, severely limiting the application of this method. Excessive use of fillers greatly reduces the flowability of the resin during infusion, making the molding process more complex.

[0004] Carbon fibers are mainly bonded to each other by epoxy resin, and there is a lack of three-dimensional structure between layers, so the carbon fiber composite laminate is mainly limited by the thermal conductivity of the interlaminar resin. Using three-dimensional preformed carbon fiber felt as a thermal transfer framework within the resin can achieve excellent thermal conductivity even with very low filler content without disrupting the molding process. However, the incorporation of carbon fiber felt alone fails to significantly improve the performance of carbon fiber composite materials.

[0005] To overcome this limitation, the present application uses an electrostatic flocking method to plant a layer of thermally conductive filler on the surface of the carbon fiber felt. The size and shape characteristics of the short carbon fibers and fillers are used to promote effective stress distribution, significantly improving the mechanical properties of the composite material and extending the phonon conduction path, thereby achieving a comprehensive improvement in the thermal conductivity and mechanics of carbon fiber composite materials. SUMMARY

[0006] The present application aims to provide a carbon fiber composite material and a preparation method thereof to solve the problems raised in the background.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A preparation method of a carbon fiber composite material, comprising the following steps: S1, dip the carbon fiber felt into the mixed solution of epoxy resin, curing agent and anhydrous ethanol for 5-10 min, and put the dipped carbon fiber felt into an oven at 60-70℃ for drying for 10-12 min; S2, evenly spread the functionalized carbon fiber on the electrostatic flocking table, place the carbon fiber felt obtained in step S1 above the electrostatic flocking table, and perform electrostatic flocking, wherein a magnetic field is arranged outside the carbon fiber felt during electrostatic flocking, and the direction of the magnetic field is perpendicular to the plane of the carbon fiber felt; S3, sequentially lay the carbon fiber felt and carbon fiber cloth completed electrostatic flocking in step S2, and press in a flat curing machine at a pressure of 4-6 MPa at 25-30℃ for 30-40 min to obtain a carbon fiber felt-carbon fiber cloth composite layer; S4, mix the carbon fiber felt-carbon fiber cloth composite layer obtained in step S3 with epoxy resin and curing agent by vacuum bag pressing process, and cure at 60-70℃ for 7-9 h to obtain a carbon fiber composite material; The preparation method of the functionalized carbon fiber in step S2 comprises the following steps: S101, add ferric chloride hexahydrate, 1,6-hexanediamine and sodium acetate to the dispersion solution of MXene, stir well, then hydrothermal reaction at 180-210℃ for 7-9 h, then separate by filtration, and then freeze-dry the filtered product to obtain a nano-Fe3O4-MXene composite material; S102, disperse the nano-Fe3O4-MXene composite material obtained in step S101 in an ethanol aqueous solution, add acetic acid to adjust the pH to 4-5, then add γ-aminopropyltriethoxysilane, and react at 60-70℃ for 1-2 h, then separate by filtration, and then dry the filtered product at 60-70℃ to constant weight to obtain a modified nano-Fe3O4-MXene composite material; S103, put the carbon fiber into 10-12 mol / L hydrochloric acid, heat to 60-80℃, and continuously react for 3-5 h, then separate by filtration, and then dry the filtered product at 90-100℃ to constant weight to obtain a modified carbon fiber; S104, disperse the modified nano-Fe3O4-MXene composite material obtained in step S102 in N,N-dimethylformamide, then add the modified carbon fiber obtained in step S103, and react at 90-100℃ for 4 h, then separate by filtration, and then dry the filtered product at 90-100℃ to constant weight to obtain a functionalized carbon fiber.

[0008] Further, the mass ratio between the epoxy resin, the curing agent and the anhydrous ethanol in the step S1 is 3:1:4; the mass ratio between the epoxy resin and the curing agent in the step S4 is 3:1.

[0009] Further, the model of the epoxy resin in the step S1 and the step S4 is E-51, and the curing agent in the step S1 and the step S4 is modified polyether amine.

[0010] Further, the carbon fiber felt in the step S2 is located at 1cm above the electrostatic flocking table, the electrostatic voltage on the surface of the carbon fiber felt is 14-16kV, and the magnetic induction intensity on the surface of the carbon fiber felt is 0.3-0.6T.

[0011] Further, the MXene dispersion liquid in the step S101 is a mixed solution of MXene, deionized water and anhydrous ethanol, and the mass ratio between the ferric chloride hexahydrate, 1,6-hexanediamine, sodium acetate, MXene, deionized water and anhydrous ethanol is 1:(3-4):(3-4):(2-6):(800-1200):(200-400).

[0012] Further, the mass ratio between the nano-magnetic four-oxide three-iron-MXene composite material, gamma-aminopropyl triethoxysilane, anhydrous ethanol and deionized water in the step S102 is 1:4:900:100.

[0013] Further, the mass ratio between the carbon fiber and hydrochloric acid in the step S103 is 1:30.

[0014] Further, the mass ratio between the modified nano-magnetic four-oxide three-iron-MXene composite material, modified carbon fiber and N,N-dimethylformamide in the step S104 is 1:(12-15):(800-1000).

[0015] A carbon fiber composite material is prepared by the preparation method of the carbon fiber composite material.

[0016] Compared with the prior art, the present application has the beneficial effects that: 1. The carbon fiber felt containing functionalized carbon fibers is introduced between the carbon fibers, the continuous heat conduction path in the thickness direction of the carbon fiber composite material is formed by using the axial heat conduction characteristics of the vertically arranged functionalized carbon fibers, and the synergistic heat conduction effect with the functionalized carbon fibers inside the carbon fiber felt is generated, which not only effectively improves the heat conduction performance of the resin area, but also effectively avoids the problem that the fillers are easy to agglomerate in the epoxy resin. 2. A layer of MXene is wrapped on the pitch-based carbon fiber powder, the interfacial thermal resistance between the carbon fiber felt and the resin is reduced, the heat conduction performance of the interlayer resin-rich area is effectively enhanced, and the interfacial bonding performance is enhanced. 3. In this invention, functionalized carbon fibers are introduced onto the surface of carbon fiber felt through electrostatic flocking and bonded to the surface of carbon fiber felt with epoxy resin. At the same time, nano-iron oxide is incorporated into the MXene material and a magnetic field is applied to work synergistically, so that the axial direction of the functionalized carbon fibers tends to extend in the direction of the magnetic field, preventing the functionalized carbon fibers from collapsing. The vertical carbon fibers further improve the overall thermal conductivity of the carbon fiber composite material. Meanwhile, the combination of nano-iron oxide and MXene can improve the overall electromagnetic shielding capability of the material. 4. The preparation method of the high radial thermal conductivity and high mechanical properties carbon fiber composite material of the present invention is simple and easy to operate, and at the same time improves the thermal conductivity and mechanical properties of carbon fiber composite material, and has good application prospects. Attached Figure Description

[0017] Figure 1 This is a process flow diagram for preparing carbon fiber composite materials according to the present invention; Figure 2 This is a process flow diagram for preparing functionalized carbon fibers in this invention; Figure 3 This is a scanning electron microscope image of the cross-section of the carbon fiber felt in Example 1 of this invention; Figure 4 This is a scanning electron microscope image of the cross-section of the carbon fiber felt in Comparative Example 1 of this invention; Figure 5 This is a scanning electron microscope image of the cross-section of the carbon fiber felt in Comparative Example 2 of this invention; Figure 6 This is a scanning electron microscope image of the interface of the carbon fiber composite material in Example 1 of this invention; Figure 7 This is a structural diagram of the apparatus for the vacuum bag pressing process in step S4 of the present invention. Detailed Implementation

[0018] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1 to 7 The present invention provides: Example 1 A method for preparing a carbon fiber composite material includes the following steps: S1, dip the carbon fiber felt into a mixed solution of epoxy resin, curing agent and anhydrous ethanol with a mass ratio of 3:1:4 for 8 min, and then place the dipped carbon fiber felt into an oven at 65℃ for drying for 11 min; S2, evenly spread 3.5g of functionalized carbon fiber on the electrostatic flocking table, place the carbon fiber felt obtained in step S1 above the electrostatic flocking table at a distance of 1cm, and perform electrostatic flocking, wherein a magnetic field is arranged outside the carbon fiber felt during the electrostatic flocking, the direction of the magnetic field is perpendicular to the plane of the carbon fiber felt, the electrostatic voltage on the surface of the carbon fiber felt is 15kV, and the magnetic induction intensity on the surface of the carbon fiber felt is 0.4T; S3, sequentially layer the carbon fiber felt and the carbon fiber cloth after electrostatic flocking in step S2, and press in a flat vulcanizing machine at a pressure of 5MPa for 35 min at 28℃ to obtain a carbon fiber felt-carbon fiber cloth composite layer; S4, form the carbon fiber felt-carbon fiber cloth composite layer obtained in step S3 into a carbon fiber composite material by a vacuum bag pressing process with a mixture of epoxy resin and curing agent with a mass ratio of 3:1, and then cure at 65℃ for 8h; The preparation method of the functionalized carbon fiber in step S2 includes the following steps: S101, add 0.1g of iron chloride hexahydrate, 0.35g of 1,6-hexanediamine and 0.35g of sodium acetate to a dispersion solution of MXene, and stir well, wherein the dispersion solution of MXene is a mixed solution of MXene, deionized water and anhydrous ethanol, and the amounts of MXene, deionized water and anhydrous ethanol are 0.5g, 100g and 25g respectively, then hydrothermal reaction is carried out at 190℃ for 8h, then the product is separated by filtration, the filtered product is washed with sufficient anhydrous ethanol, and then freeze-dried to obtain a nano-Fe3O4-MXene composite material; S102, disperse 0.4g of the nano-Fe3O4-MXene composite material obtained in step S101 in an ethanol aqueous solution, wherein the amounts of anhydrous ethanol and deionized water in the ethanol aqueous solution are 360g and 40g respectively, add acetic acid to adjust the pH to 4.5, then add 1.6g of γ-aminopropyltriethoxysilane, and react at 65℃ for 1.5h, then separate by filtration, wash the filtered product with sufficient anhydrous ethanol, and then dry at 65℃ to a constant weight to obtain a modified nano-Fe3O4-MXene composite material; S103, place 5g of carbon fiber into 150g of hydrochloric acid with a concentration of 11mol / L, heat to 70℃, and continuously react for 4h, then separate by filtration, wash the filtered product with deionized water, and then dry at 95℃ to a constant weight to obtain modified carbon fiber; S104, 0.3 g of the modified nano-magnetite-MXene composite obtained in step S102 is dispersed in 270 g of N,N-dimethylformamide, then 4.2 g of the modified carbon fiber obtained in step S103 is added, and the mixture is reacted at 95°C for 4 h, then filtered and separated, and the filtered product is washed with sufficient ethanol water solution with a mass ratio of 1:1 and dried at 95°C to constant weight to obtain the functionalized carbon fiber.

[0020] Example 2 A method for preparing a carbon fiber composite material, comprising the following steps: S1, the carbon fiber felt is immersed in a mixed solution of epoxy resin, curing agent and anhydrous ethanol with a mass ratio of 3:1:4 for 5 min, and the immersed carbon fiber felt is placed in an oven at 60°C and dried for 10 min; S2, 3.5 g of the functionalized carbon fiber is evenly spread on the electrostatic flocking table, and the carbon fiber felt obtained in step S1 is placed 1 cm above the electrostatic flocking table, electrostatic flocking is carried out, and a magnetic field is arranged outside the carbon fiber felt during electrostatic flocking, the direction of the magnetic field is perpendicular to the plane of the carbon fiber felt, the electrostatic voltage on the surface of the carbon fiber felt is 14 kV, and the magnetic induction intensity on the surface of the carbon fiber felt is 0.3 T; S3, the carbon fiber felt and the carbon fiber cloth subjected to electrostatic flocking in step S2 are sequentially layered, and are pressed in a flat plate curing machine at 25°C and a pressure of 4 MPa for 30 min to obtain a carbon fiber felt-carbon fiber cloth composite layer; S4, the carbon fiber felt-carbon fiber cloth composite layer obtained in step S3 is formed by vacuum bag pressing process with a mixture of epoxy resin and curing agent with a mass ratio of 3:1, and is cured at 60°C for 7 h to obtain a carbon fiber composite material; The method for preparing the functionalized carbon fiber in step S2 comprises the following steps: S101, 0.3 g of ferric chloride hexahydrate, 0.9 g of 1,6-hexanediamine and 0.9 g of sodium acetate are added to a dispersion of MXene, the dispersion of MXene being a mixed solution of MXene, deionized water and anhydrous ethanol, and the amounts of MXene, deionized water and anhydrous ethanol are 0.6 g, 240 g and 60 g respectively, then the mixture is hydrothermally reacted at 180°C for 7 h, then filtered and separated, the filtered product is washed with sufficient anhydrous ethanol, and then freeze-dried to obtain a nano-magnetite-MXene composite material; S102, 0.4 g of the nanometer four-iron oxide-MXene composite material obtained in step S101 is dispersed in an ethanol aqueous solution, the amounts of anhydrous ethanol and deionized water in the ethanol aqueous solution are 360 g and 40 g respectively, acetic acid is added dropwise to adjust the pH to 4, then 1.6 g of gamma-aminopropyl triethoxysilane is added, and the reaction is carried out at 60 DEG C for 1 h, after which the product is separated by filtration, the filtered product is washed with sufficient anhydrous ethanol, and then dried at 60 DEG C to constant weight to obtain a modified nanometer four-iron oxide-MXene composite material; S103, 5 g of carbon fiber is placed into 150 g of hydrochloric acid with a concentration of 10 mol / L, heated to 60 DEG C, and continuously reacted for 3 h, after which the product is separated by filtration, the filtered product is washed with deionized water, and then dried at 90 DEG C to constant weight to obtain a modified carbon fiber; S104, 0.33 g of the modified nanometer four-iron oxide-MXene composite material obtained in step S102 is dispersed in 267 g of N,N-dimethylformamide, then 4 g of the modified carbon fiber obtained in step S103 is added, and the reaction is carried out at 90 DEG C for 4 h, after which the product is separated by filtration, the filtered product is washed with sufficient ethanol aqueous solution with a mass ratio of 1:1, and then dried at 90 DEG C to constant weight to obtain a functionalized carbon fiber.

[0021] Example 3 A method for preparing a carbon fiber composite material, comprising the following steps: S1, carbon fiber felt is immersed in a mixed solution of epoxy resin, curing agent and anhydrous ethanol with a mass ratio of 3:1:4 for 10 min, and the immersed carbon fiber felt is placed in an oven at 70 DEG C for drying for 12 min; S2, the functionalized carbon fiber is evenly spread on the electrostatic flocking table, the carbon fiber felt obtained in step S1 is placed 1 cm above the electrostatic flocking table, electrostatic flocking is carried out, and a magnetic field is arranged outside the carbon fiber felt during the electrostatic flocking, the direction of the magnetic field is perpendicular to the plane of the carbon fiber felt, the electrostatic voltage on the surface of the carbon fiber felt is 16 kV, and the magnetic induction intensity on the surface of the carbon fiber felt is 0.6 T; S3, the carbon fiber felt and the carbon fiber cloth which have completed electrostatic flocking in step S2 are sequentially layered, and are pressed in a flat plate vulcanizing machine at a pressure of 6 MPa for 40 min at 30 DEG C to obtain a carbon fiber felt-carbon fiber cloth composite layer; S4, the carbon fiber felt-carbon fiber cloth composite layer obtained in step S3 is formed by a vacuum bag pressing process with a mixture of epoxy resin and curing agent with a mass ratio of 3:1, and is cured at 70 DEG C for 9 h to obtain a carbon fiber composite material; The method for preparing the functionalized carbon fiber in step S2 comprises the following steps: S101, 0.1 g of ferric chloride hexahydrate, 0.4 g of 1,6 hexanediamine and 0.4 g of sodium acetate are added to a dispersion liquid of MXene, the dispersion liquid of MXene is a mixed solution of MXene, deionized water and anhydrous ethanol, and the dosages of MXene, deionized water and anhydrous ethanol are 0.6 g, 120 g and 40 g respectively, then hydrothermal reaction is carried out at 210℃ for 9 h, after that, filtration separation is carried out, the filtration product is cleaned by sufficient anhydrous ethanol, and then freeze-drying is carried out to obtain a nano magnetite-MXene composite material; S102, 0.4 g of the nano magnetite-MXene composite material obtained in step S101 is dispersed into an ethanol aqueous solution, the dosages of anhydrous ethanol and deionized water in the ethanol aqueous solution are 360 g and 40 g respectively, acetic acid is added dropwise to adjust the pH to 5, then 1.6 g of γ-aminopropyl triethoxysilane is added, reaction is carried out at 70℃ for 2 h, after that, filtration separation is carried out, the filtration product is cleaned by sufficient anhydrous ethanol, and then drying is carried out at 70℃ to a constant weight to obtain a modified nano magnetite-MXene composite material; S103, 5 g of carbon fiber is put into 150 g of hydrochloric acid with a concentration of 12 mol / L, heated to 80℃, and continuously reacted for 5 h, after that, filtration separation is carried out, the filtration product is cleaned by deionized water, and then drying is carried out at 100℃ to a constant weight to obtain a modified carbon fiber; S104, 0.27 g of the modified nano magnetite-MXene composite material obtained in step S102 is dispersed into 267 g of N,N-dimethylformamide, after that, 4 g of the modified carbon fiber obtained in step S103 is added, reaction is carried out at 100℃ for 4 h, after that, filtration separation is carried out, the filtration product is cleaned by sufficient ethanol aqueous solution with a mass ratio of 1:1, and then drying is carried out at 100℃ to a constant weight to obtain a functionalized carbon fiber.

[0022] Example 4 A preparation method of a carbon fiber composite material, comprising the following steps: S1, carbon fiber felt is immersed in a mixed solution of epoxy resin, curing agent and anhydrous ethanol with a mass ratio of 3:1:4 for 8 min, and the immersed carbon fiber felt is placed in an oven at 60℃ for drying for 12 min; S2, 3.5 g of the functionalized carbon fiber is uniformly spread on an electrostatic flocking table, the carbon fiber felt obtained in step S1 is placed 1 cm above the electrostatic flocking table, electrostatic flocking is carried out, a magnetic field is arranged outside the carbon fiber felt during the electrostatic flocking, the direction of the magnetic field is perpendicular to the plane of the carbon fiber felt, the electrostatic voltage on the surface of the carbon fiber felt is 15 kV, and the magnetic induction intensity on the surface of the carbon fiber felt is 0.4 T; S3, the carbon fiber felt and the carbon fiber cloth completed electrostatic flocking in step S2 are sequentially laminated, and are pressed in a flat plate vulcanizing machine at 28 DEG C for 35 min at a pressure of 4.5 MPa to obtain a carbon fiber felt-carbon fiber cloth composite layer; S4, the carbon fiber felt-carbon fiber cloth composite layer obtained in step S3 is formed by a vacuum bag pressing process with a mixture of epoxy resin and curing agent in a mass ratio of 3:1, and is cured at 65 DEG C for 8.5 h to obtain a carbon fiber composite material; The preparation method of the functionalized carbon fiber in step S2 includes the following steps: S101, 0.2g of ferric chloride hexahydrate, 0.7g of 1,6 hexanediamine and 0.8g of sodium acetate are added to a dispersion solution of MXene, the dispersion solution of MXene is a mixed solution of MXene, deionized water and anhydrous ethanol, and the amounts of MXene, deionized water and anhydrous ethanol are 0.6g, 200g and 60g respectively, then hydrothermal reaction is carried out at 200 DEG C for 8.5h, then filtration separation is carried out, the filtration product is washed with sufficient anhydrous ethanol, and then freeze-drying is carried out to obtain a nano magnetite-MXene composite material; S102, 0.4g of the nano magnetite-MXene composite material obtained in step S101 is dispersed in an ethanol aqueous solution, the amounts of anhydrous ethanol and deionized water in the ethanol aqueous solution are 360g and 40g respectively, acetic acid is added dropwise to adjust the pH to 4, then 1.6g of gamma-aminopropyl triethoxysilane is added, reaction is carried out at 65 DEG C for 1.5h, then filtration separation is carried out, the filtration product is washed with sufficient anhydrous ethanol, and then drying is carried out at 60 DEG C to constant weight to obtain a modified nano magnetite-MXene composite material; S103, 5g of carbon fiber is put into 150g of hydrochloric acid with a concentration of 12mol / L, heated to 65 DEG C, and continuously reacted for 5h, then filtration separation is carried out, the filtration product is washed with deionized water, and then drying is carried out at 90 DEG C to constant weight to obtain modified carbon fiber; S104, 0.3g of the modified nano magnetite-MXene composite material obtained in step S102 is dispersed in 280g of N,N-dimethylformamide, then 4.5g of the modified carbon fiber obtained in step S103 is added, reaction is carried out at 90 DEG C for 4h, then filtration separation is carried out, the filtration product is washed with sufficient ethanol aqueous solution with a mass ratio of 1:1, and then drying is carried out at 100 DEG C to constant weight to obtain functionalized carbon fiber.

[0023] The vacuum bag pressing process in step S4 in the application specifically includes the following steps: Reference Figure 7The carbon fiber felt-carbon fiber cloth composite layer obtained in step S3 is placed on a mold, release cloth and flow guide net are sequentially laid on the carbon fiber felt-carbon fiber cloth composite layer, and finally the carbon fiber felt-carbon fiber cloth composite layer is sealed with a vacuum bag, a gap is left on the left side and a gap is left on the right side, a glue pipe and an air pipe are inserted into the gaps, respectively, a vacuum pump is used to press the epoxy resin and the curing agent into the mold, the vacuum pump is turned off after impregnation is completed, the two side pipes are sealed, and a carbon fiber composite material is obtained after demolding after temperature rising and curing.

[0024] The thickness of the carbon fiber felt used in the application is 0.1 mm, the thickness of the carbon fiber cloth is 0.5 mm, the area of the carbon fiber felt and the carbon fiber cloth is 200 mm*120 mm, and the length of the carbon fiber is 300-400 mu m.

[0025] The model of the epoxy resin in steps S1 and S4 in the application is E-51, and the curing agent in steps S1 and S4 is modified polyether amine.

[0026] The preparation method of MXene in the application is as follows: 9 mol / L hydrochloric acid and lithium fluoride are stirred uniformly, then MAX phases are added in batches, the mass ratio of hydrochloric acid, lithium fluoride and MAX phases is 40:2:1, stirring is carried out at 35 DEG C for 24 h, then washing is carried out until neutral, then MXene upper dispersion liquid is obtained after ethanol intercalation, and MXene is obtained after freeze-drying of the dispersion liquid.

[0027] The application comprises the following comparative examples. Comparative example 1 Comparative example 1 and example 1 are different in that step S101 is completely cancelled, MXene is directly added to step S102, the modified nano-magnetic iron oxide-MXene composite material added in step S104 is changed to MXene treated by step S102, the same mass is added, and the remaining steps are completely same as example 1.

[0028] Comparative example 2 Comparative example 2 and example 1 are different in that the magnetic field in step S2 is completely cancelled, and the remaining steps are completely same as example 1.

[0029] Comparative example 3 Comparative example 3 and example 1 are different in that steps S101 and S102 are cancelled, and the modified nano-magnetic iron oxide-MXene composite material added in step S104 is completely cancelled, and the remaining steps are completely same as example 1.

[0030] Comparative example 4 Comparative example 4 and example 1 are different in that step S2 is completely cancelled, and the remaining steps are completely same as example 1.

[0031] Comparative example 5 The difference between Comparative Example 5 and Example 1 is that step S102 is completely cancelled, and the remaining steps are completely the same as Example 1.

[0032] The carbon fiber composites prepared in Examples 1-4 and Comparative Examples 1-5 were tested for performance, the flexural strength test was performed according to ASTM D790, the interlaminar shear strength test was performed according to ASTM D2344, and the thermal conductivity test was performed according to ASTM-E1461, and the test results are shown in Table 1. Table 1: Performance test results of carbon fiber composites prepared in Examples 1-4 and Comparative Examples 1-5 Figure 3 、 Figure 4 and Figure 5 are scanning electron microscope images of carbon fiber mats of Example 1, Comparative Example 1 and Comparative Example 2, respectively, from which it can be clearly seen that the carbon fibers of Example 1 are more vertical relative to Comparative Examples 1 and 2, which is due to the application of a magnetic field during electrostatic flocking, which, under the action of nanometer-sized ferrite, makes the functionalized carbon fibers more vertical on the surface of the carbon fiber mat, which can effectively improve the overall thermal conductivity of the material; In Comparative Example 3, the MXene coating on the surface of the carbon fiber is completely cancelled, which greatly reduces the contact performance with the epoxy resin, and the thermal conductivity and mechanical strength are significantly reduced; In Comparative Example 4, electrostatic flocking is completely cancelled, and the role of carbon fibers is lost, and the thermal conductivity and mechanical strength of the entire carbon fiber composite material are the lowest; In Comparative Example 5, step S102 is cancelled, and the MXene and carbon fibers are adsorbed through positive and negative ions, which, relative to the amide bond connection between MXene and carbon fibers in Example 1, reduces the chemical bonding effect, increases the interfacial thermal resistance between the carbon fiber mat and the resin, and reduces the thermal conductivity.

[0033] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for producing a carbon fiber composite material, characterized by, It comprises the following steps: S1, dip the carbon fiber felt into the mixed solution of epoxy resin, curing agent and anhydrous ethanol for 5-10 min, and put the dipped carbon fiber felt into the oven at 60-70 DEG C for 10-12 min; S2, evenly spread the functionalized carbon fiber on the electrostatic flocking table, place the carbon fiber felt obtained in step S1 above the electrostatic flocking table, and electrostatic flocking is carried out, and a magnetic field is arranged outside the carbon fiber felt during electrostatic flocking, and the direction of the magnetic field is perpendicular to the plane of the carbon fiber felt; S3, the carbon fiber felt and the carbon fiber cloth completed in step S2 are sequentially layered, and are pressed in a flat vulcanizing machine at a pressure of 4-6 MPa at 25-30 DEG C for 30-40 min to obtain a carbon fiber felt-carbon fiber cloth composite layer; S4, the carbon fiber felt-carbon fiber cloth composite layer obtained in step S3 is mixed with epoxy resin and curing agent by vacuum bag pressing process, and is cured at 60-70 DEG C for 7-9 h to obtain a carbon fiber composite material; The preparation method of the functionalized carbon fiber in step S2 comprises the following steps: S101, add ferric chloride hexahydrate, 1,6-hexanediamine and sodium acetate into the dispersion liquid of MXene, stir well, then hydrothermal reaction at 180-210 DEG C for 7-9 h, then filter and separate, the filtered product is washed with sufficient anhydrous ethanol, then freeze-dried to obtain nano-Fe3O4-MXene composite material; S102, disperse the nano-Fe3O4-MXene composite material obtained in step S101 into an ethanol aqueous solution, add acetic acid dropwise to adjust the pH to 4-5, then add gamma-aminopropyltriethoxysilane, and react at 60-70 DEG C for 1-2 h, then filter and separate, and the filtered product is washed with sufficient anhydrous ethanol, then dried at 60-70 DEG C to constant weight to obtain modified nano-Fe3O4-MXene composite material; S103, put the carbon fiber into 10-12 mol / L hydrochloric acid, heat to 60-80 DEG C, and continuously react for 3-5 h, then filter and separate, and the filtered product is washed with deionized water, then dried at 90-100 DEG C to constant weight to obtain modified carbon fiber; S104, disperse the modified nano-Fe3O4-MXene composite material obtained in step S102 into N,N-dimethylformamide, then add the modified carbon fiber obtained in step S103, and react at 90-100 DEG C for 4 h, then filter and separate, and the filtered product is washed with sufficient ethanol aqueous solution with a mass ratio of 1:1, then dried at 90-100 DEG C to constant weight to obtain functionalized carbon fiber.

2. The method for producing a carbon fiber composite material according to claim 1, characterized by, The mass ratio of epoxy resin, curing agent and anhydrous ethanol in step S1 is 3:1:4; the mass ratio of epoxy resin and curing agent in step S4 is 3:

1.

3. The method for producing a carbon fiber composite material according to claim 2, characterized by, The type of epoxy resin in steps S1 and S4 is E-51, and the curing agent in steps S1 and S4 is modified polyether amine.

4. The method for producing a carbon fiber composite material according to claim 1, characterized by, The carbon fiber felt in the step S2 is located 1 cm above the electrostatic flocking table, the electrostatic voltage on the surface of the carbon fiber felt is 14-16 kV, and the magnetic induction intensity on the surface of the carbon fiber felt is 0.3-0.6 T.

5. The method for preparing carbon fiber composite material according to claim 1, characterized in that, The MXene dispersion liquid in the step S101 is a mixed solution of MXene, deionized water and anhydrous ethanol, and the mass ratio between the iron chloride hexahydrate, 1,6-hexanediamine, sodium acetate, MXene, deionized water and anhydrous ethanol is 1:(3-4):(3-4):(2-6):(800-1200):(200-400).

6. The method for producing a carbon fiber composite material according to claim 1, characterized by, The mass ratio between the nanometer ferroferric oxide-MXene composite material, gamma-aminopropyl triethoxysilane, anhydrous ethanol and deionized water in the step S102 is 1:4:900:

100.

7. The method for preparing carbon fiber composite material according to claim 1, characterized in that, The mass ratio between the carbon fiber and hydrochloric acid in the step S103 is 1:

30.

8. The method for preparing carbon fiber composite material according to claim 1, characterized in that, The mass ratio between the modified nanometer ferroferric oxide-MXene composite material, modified carbon fiber and N,N-dimethylformamide in the step S104 is 1:(12-15):(800-1000).

9. A carbon fiber composite material, characterized by, The carbon fiber composite material is prepared by the preparation method of the carbon fiber composite material according to any one of claims 1-8.

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