Preparation process of impact-resistant carbon fiber foam composite material

Abstract

The invention discloses a preparation process of an impact-resistant carbon fiber foam composite material, and belongs to the field of foam composite materials. The preparation process comprises the following steps: pretreating Chinese alpine rush to obtain a carbon precursor, mixing the carbon precursor, a coupling agent and absolute ethyl alcohol to carry out a first impregnation reaction, adding modified carbon fibers and a first catalyst to carry out a second impregnation reaction after the reaction is finished to obtain a precursor, and carrying out pyrolytic reaction on the precursor to obtain the impact-resistant carbon fiber foam composite material. The porosity is increased by introducing Mg-MOF, the pore distribution is optimized by a cross-linked network of the connecting agent and cellulose, so that the pore distribution is more uniform, and the optimized pore structure not only improves the energy absorption capacity of the composite material, but also reduces stress concentration; the interface bonding strength of the fiber and a matrix is remarkably enhanced through mutual cooperation of multiple effects, so that impact energy can be more uniformly distributed in the whole material, and the impact resistance is improved.

Description

Technical Field

[0001] The present invention relates to the field of foam composite materials, and particularly to a preparation process of an impact-resistant carbon fiber foam composite material. Background Art

[0002] As a lightweight and high-strength multifunctional material, carbon fiber foam composite materials have received extensive attention in the engineering field in recent years. Its unique pore structure can not only effectively absorb and disperse impact energy, but also exhibit excellent thermal shock stability in high-temperature environments. However, traditional preparation methods often make it difficult to simultaneously achieve high impact resistance and an optimized pore structure, resulting in many challenges in the practical application of the materials.

[0003] Although the impact resistance of carbon fiber foam composite materials has been significantly improved compared with traditional carbon fiber composite materials, the existing technologies still have the following problems: First, the energy absorption mechanism is single. At present, the impact resistance of carbon fiber foam composite materials mainly relies on the plastic deformation of the foam structure and pore collapse to absorb energy, but under high-speed impact conditions, the energy absorption efficiency of this mechanism will significantly decrease. Second, the interfacial bonding strength is low. The interfacial bonding strength between carbon fibers and the foam matrix is insufficient, and delamination failure is likely to occur during the impact process, reducing the overall performance of the material. In addition, the fiber arrangement and foam structure of traditional carbon fiber foam composite materials usually have obvious directionality, resulting in significant differences in the impact resistance of the material in different directions, which limits its reliability in practical applications.

[0004] Porosity is a key structural parameter of carbon fiber foam composite materials, directly affecting the impact resistance, mechanical properties and lightweight effect of the materials. However, the existing technologies have the following problems in porosity control: First, the porosity distribution is uneven. Traditional preparation methods are difficult to precisely control the porosity distribution of the foam structure, resulting in local high-density or low-density regions inside the material, which may cause stress concentration and accelerate material failure. Second, it is difficult to regulate the pore shape and size. Existing technologies usually have difficulty in precisely regulating the pore shape and size, resulting in a large randomness of the pore structure and unable to fully exert the energy absorption potential of the foam structure. In addition, it is difficult to balance high porosity and high strength. Increasing the porosity can enhance the energy absorption capacity of the material, but at the same time will reduce the overall strength and stiffness of the material. The existing technologies have obvious deficiencies in this balance. Chinese invention patent CN105924207B discloses a preparation method of silicon carbide foam ceramics, with a simple process and a short preparation period, and can adjust the porosity of silicon carbide foam ceramics within a certain range, but this application does not involve the impact resistance of silicon carbide foam ceramics.

[0005] Therefore, in order to overcome the deficiencies of the prior art in terms of impact resistance performance and porosity control, the present invention provides a preparation process for an impact-resistant carbon fiber foam composite material. Summary of the Invention

[0006] To solve the problems existing in the prior art, the present invention provides a preparation process for an impact-resistant carbon fiber foam composite material. Specifically, the technical solution of the present invention includes the following: A preparation process for an impact-resistant carbon fiber foam composite material, the preparation process comprising the following steps: The Chinese alpine rush is pretreated to obtain a carbon precursor. The carbon precursor, a coupling agent, and absolute ethanol are mixed for a first impregnation reaction. After the reaction ends, modified carbon fibers and a first catalyst are added for a second impregnation reaction to obtain a precursor, and the precursor is pyrolyzed to obtain the impact-resistant carbon fiber foam composite material.

[0007] Further, the preparation method of the coupling agent includes the following steps: Dicyandiamide, methylhydrodichlorosilane, and a second catalyst are dispersed in n-hexane, and a stirring reaction is carried out in an inert gas protection environment to obtain the coupling agent.

[0008] Further, the preparation method of the modified carbon fibers includes the following steps: The chopped carbon fibers are successively subjected to desizing treatment and oxidation treatment to obtain oxidized carbon fibers. Magnesium nitrate hexahydrate and 2-aminoterephthalic acid are mixed with a mixed solvent for a reaction to obtain a mixture, and the oxidized carbon fibers are dispersed in the mixture for a solvothermal reaction to obtain the modified carbon fibers.

[0009] Further, the weight ratio of the dicyandiamide, methylhydrodichlorosilane, and the second catalyst is 45-60:20-25:10-15.

[0010] Further, the second catalyst is triethylamine.

[0011] Further, the stirring reaction includes a reaction temperature of 5-15 °C and a reaction time of 3-4 h.

[0012] Further, the desizing treatment is ultrasonic treatment in acetone for 10-20 min, followed by heat preservation at 80-85 °C for 8-10 h.

[0013] Further, the oxidation treatment is heat preservation in 65% concentrated nitric acid at 60-70 °C for 2-3 h.

[0014] Further, the weight ratio of the magnesium nitrate hexahydrate and 2-aminoterephthalic acid is 10-15:2-3.

[0015] Further, the mixed solvent is prepared from N,N-dimethylformamide, absolute ethanol, and deionized water according to a volume ratio of 15:1:1.

[0016] Further, the weight ratio of magnesium nitrate hexahydrate to oxidized carbon fiber is 10-15:5-8.

[0017] Further, the thermal reaction includes a reaction temperature of 120-125°C and a reaction time of 20-24 h.

[0018] Further, the weight ratio of the carbon precursor, the linker, and the modified carbon fiber is 10-15:15-30:1-2.

[0019] Further, the first impregnation reaction includes a reaction temperature of 60-70°C and a reaction time of 12-24 h.

[0020] Further, the weight ratio of the modified carbon fiber to the first catalyst is 1-2:0.15-0.25.

[0021] Further, the first catalyst is scandium trifluoromethanesulfonate.

[0022] Further, the second impregnation reaction includes a reaction temperature of 25-30°C and a reaction time of 4-6 h.

[0023] Further, the inert gas is nitrogen.

[0024] Further, the pyrolysis reaction includes a reaction temperature of 1000-1500°C and a reaction time of 3-4 h.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In the present invention, dicyandiamide is grafted onto methylhydrodichlorosilane through an ammonolysis reaction to obtain a linker. Oxidized carbon fiber is obtained by subjecting chopped carbon fiber to desizing and oxidation treatments. Using 2-aminoterephthalic acid as an organic ligand and Mg in magnesium nitrate hexahydrate 2+ as an open metal site, Mg-MOF is synthesized on the surface of the oxidized carbon fiber to obtain modified carbon fiber; using the product of heat-treated Chinese alpine rush - the carbon precursor as the carbon skeleton, the amino group and the silicon-hydrogen bond in the linker cooperate with the hydrogen bond to form a stable three-dimensional crosslinked network with cellulose in Chinese alpine rush. The amino group in the modified carbon fiber undergoes a transamination reaction with C=N in the linker to connect the modified carbon fiber to the three-dimensional crosslinked network, and an impact-resistant carbon fiber foam composite material is prepared through a pyrolysis reaction.

[0026] (2) In the present invention, dicyandiamide is grafted onto methylhydrodichlorosilane through an ammonolysis reaction to form a linker with amino groups and silicon-hydrogen bonds. These functional groups form hydrogen bonds with the hydroxyl groups in Chinese alpine rush cellulose, constructing a stable three-dimensional crosslinked network. The amino groups in the modified carbon fiber undergo a transamination reaction with C=N in the linker, firmly connecting the modified carbon fiber to the three-dimensional crosslinked network. The introduction of Mg-MOF increases the porosity, while the crosslinked network of the linker and cellulose optimizes the pore distribution, making it more uniform. This optimized pore structure not only improves the energy absorption capacity of the composite material but also reduces stress concentration. The above-mentioned multiple effects synergistically enhance the interfacial bonding strength between the fiber and the matrix, enabling the impact energy to be more evenly distributed throughout the composite material, thereby improving the impact resistance performance.

[0027] (3) The porous structure of Mg-MOF increases the porosity and pore connectivity of the carbon fiber foam composite material, thereby reducing the concentration of thermal stress and enhancing the thermal shock stability of the composite material. The connection of the modified carbon fiber enhances the interfacial bonding strength between the fiber and the matrix, enabling the material to better resist interfacial delamination caused by thermal stress during the thermal shock process. In addition, the pyrolysis reaction not only removes organic impurities but also further optimizes the pore structure of the composite material through high-temperature treatment, enabling it to exhibit excellent thermal shock stability in a high-temperature environment. This multi-faceted synergistic effect enables the composite material to better disperse stress and reduce stress concentration during the thermal shock process, thereby significantly enhancing its thermal shock resistance performance.

[0028] (4) The present invention uses Chinese alpine rush as the raw material, which has a low cost. At the same time, it reduces the burning or stacking of agricultural waste and reduces environmental pollution. Specific Embodiments

[0029] The technical solutions of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0030] Unless otherwise specified, the raw materials and reagents used in the present invention below are all commercially available products or can be prepared by known methods.

[0031] Preparation Example 1: Preparation of the linker, including the following steps: 45 parts by weight of dicyandiamide, 20 parts by weight of methylhydrodichlorosilane, and 10 parts by weight of triethylamine are dispersed in 500 parts by weight of n-hexane, and stirred and reacted at 5°C for 3 h in a nitrogen protection environment. After the reaction, the linker is obtained by filtration and rotary evaporation.

[0032] Preparation Example 2: Preparation of the coupling agent, including the following steps: 50 parts by weight of dicyandiamide, 21 parts by weight of methyldichlorosilane, and 12 parts by weight of triethylamine are dispersed in 500 parts by weight of n-hexane, and stirred and reacted at 8 °C for 3.2 h in a nitrogen protection environment. After the reaction, the coupling agent is obtained by filtration and rotary evaporation.

[0033] Preparation Example 3: Preparation of the coupling agent, including the following steps: 55 parts by weight of dicyandiamide, 23 parts by weight of methyldichlorosilane, and 13 parts by weight of triethylamine are dispersed in 500 parts by weight of n-hexane, and stirred and reacted at 10 °C for 3.7 h in a nitrogen protection environment. After the reaction, the coupling agent is obtained by filtration and rotary evaporation.

[0034] Preparation Example 4: Preparation of the coupling agent, including the following steps: 60 parts by weight of dicyandiamide, 25 parts by weight of methyldichlorosilane, and 15 parts by weight of triethylamine are dispersed in 500 parts by weight of n-hexane, and stirred and reacted at 15 °C for 4 h in a nitrogen protection environment. After the reaction, the coupling agent is obtained by filtration and rotary evaporation.

[0035] Preparation Example 5: Preparation of the coupling agent, including the following steps: 60 parts by weight of 1,2-propanediamine, 25 parts by weight of methyldichlorosilane, and 15 parts by weight of triethylamine are dispersed in 500 parts by weight of n-hexane, and stirred and reacted at 15 °C for 4 h in a nitrogen protection environment. After the reaction, the coupling agent is obtained by filtration and rotary evaporation.

[0036] Preparation Example 6: Preparation of the coupling agent, including the following steps: 60 parts by weight of dicyandiamide and 15 parts by weight of triethylamine are dispersed in 500 parts by weight of n-hexane, and stirred and reacted at 15 °C for 4 h in a nitrogen protection environment. After the reaction, the coupling agent is obtained by filtration and rotary evaporation.

[0037] Preparation Example 7: Preparation of the modified carbon fiber, including the following steps: The chopped carbon fiber is dispersed in acetone and ultrasonically treated for 10 min, then subjected to desizing treatment at 80 °C for 8 h. After the heat preservation, it is dried for 24 h in an environment of 60 °C to obtain desized carbon fiber; the desized carbon fiber is dispersed in concentrated nitric acid with a concentration of 65%, and subjected to oxidation treatment at 60 °C for 2 h. After the heat preservation, it is rinsed several times with distilled water to remove the residual acid on the surface, and dried for 24 h in an environment of 60 °C to obtain oxidized carbon fiber; 10 parts by weight of magnesium nitrate hexahydrate and 2 parts by weight of 2-aminoterephthalic acid are dispersed in 300 parts by weight of a mixed solvent (VN,N-二甲基甲酰胺 : V 无水乙醇 : V 去离子水 = 15:1:1), a mixture is obtained. 5 parts by weight of oxidized carbon fiber is dispersed in the above mixture, and the mixture is kept at 120 °C for 20 h for solvothermal reaction. After the reaction is completed, it is washed and dried to obtain modified carbon fiber.

[0038] Preparation Example 8: Preparation of modified carbon fiber, including the following steps: The chopped carbon fiber is dispersed in acetone and ultrasonically treated for 12 min, then kept at 81 °C for 8.5 h for desizing treatment. After the heat preservation is completed, it is dried in an environment at 65 °C for 24 h to obtain desized carbon fiber; the desized carbon fiber is dispersed in concentrated nitric acid with a concentration of 65%, and kept at 62 °C for 3 h for oxidation treatment. After the heat preservation is completed, it is rinsed several times with distilled water to remove the residual acid on the surface, and dried in an environment at 63 °C for 24 h to obtain oxidized carbon fiber; 12 parts by weight of magnesium nitrate hexahydrate and 2.3 parts by weight of 2-aminoterephthalic acid are dispersed in 300 parts by weight of a mixed solvent (V N,N-二甲基甲酰胺 : V 无水乙醇 : V 去离子水 = 15:1:1), a mixture is obtained. 6 parts by weight of oxidized carbon fiber is dispersed in the above mixture, and the mixture is kept at 121 °C for 22 h for solvothermal reaction. After the reaction is completed, it is washed and dried to obtain modified carbon fiber.

[0039] Preparation Example 9: Preparation of modified carbon fiber, including the following steps: The chopped carbon fiber is dispersed in acetone and ultrasonically treated for 15 min, then kept at 83 °C for 9 h for desizing treatment. After the heat preservation is completed, it is dried in an environment at 70 °C for 24 h to obtain desized carbon fiber; the desized carbon fiber is dispersed in concentrated nitric acid with a concentration of 65%, and kept at 66 °C for 4 h for oxidation treatment. After the heat preservation is completed, it is rinsed several times with distilled water to remove the residual acid on the surface, and dried in an environment at 67 °C for 24 h to obtain oxidized carbon fiber; 13 parts by weight of magnesium nitrate hexahydrate and 2.5 parts by weight of 2-aminoterephthalic acid are dispersed in 300 parts by weight of a mixed solvent (V N,N-二甲基甲酰胺 : V 无水乙醇 : V 去离子水 = 15:1:1), a mixture is obtained. 57 parts by weight of oxidized carbon fiber is dispersed in the above mixture, and the mixture is kept at 123 °C for 23 h for solvothermal reaction. After the reaction is completed, it is washed and dried to obtain modified carbon fiber.

[0040] Preparation Example 10: Preparation of modified carbon fiber, including the following steps: The chopped carbon fibers were dispersed in acetone and ultrasonically treated for 20 min, then kept at 85 °C for 10 h for desizing treatment. After the heat preservation ended, they were dried at 80 °C for 24 h to obtain desized carbon fibers; the desized carbon fibers were dispersed in concentrated nitric acid with a concentration of 65%, and kept at 70 °C for 6 h for oxidation treatment. After the heat preservation ended, they were rinsed several times with distilled water to remove the residual acid on the surface, and dried at 70 °C for 24 h to obtain oxidized carbon fibers; 15 parts by weight of magnesium nitrate hexahydrate and 3 parts by weight of 2-aminoterephthalic acid were dispersed in 300 parts by weight of a mixed solvent (V N,N-二甲基甲酰胺 :V 无水乙醇 :V 去离子水 =15:1:1) to obtain a mixture. 8 parts by weight of the oxidized carbon fibers were dispersed in the above mixture and kept at 125 °C for 24 h for a solvothermal reaction. After the reaction ended, they were washed and dried to obtain modified carbon fibers.

[0041] Preparation Example 11: Preparation of modified carbon fibers, including the following steps: The chopped carbon fibers were dispersed in acetone and ultrasonically treated for 20 min, then kept at 85 °C for 10 h for desizing treatment. After the heat preservation ended, they were dried at 80 °C for 24 h to obtain desized carbon fibers; the desized carbon fibers were dispersed in concentrated nitric acid with a concentration of 65%, and kept at 70 °C for 6 h for oxidation treatment. After the heat preservation ended, they were rinsed several times with distilled water to remove the residual acid on the surface, and dried at 70 °C for 24 h to obtain oxidized carbon fibers; 15 parts by weight of magnesium nitrate hexahydrate and 3 parts by weight of terephthalic acid were dispersed in 300 parts by weight of a mixed solvent (V N,N-二甲基甲酰胺 :V 无水乙醇 :V 去离子水 =15:1:1) to obtain a mixture. 8 parts by weight of the oxidized carbon fibers were dispersed in the above mixture and kept at 125 °C for 24 h for a solvothermal reaction. After the reaction ended, they were washed and dried to obtain modified carbon fibers.

[0042] Preparation Example 12: Preparation of modified carbon fibers, including the following steps: The chopped carbon fibers were dispersed in acetone and ultrasonically treated for 20 min, then kept at 85 °C for 10 h for desizing treatment. After the heat preservation ended, they were dried at 80 °C for 24 h to obtain desized carbon fibers; the desized carbon fibers were dispersed in concentrated nitric acid with a concentration of 65%, and kept at 70 °C for 6 h for oxidation treatment. After the heat preservation ended, they were rinsed several times with distilled water to remove the residual acid on the surface, and dried at 70 °C for 24 h to obtain oxidized carbon fibers; 15 parts by weight of manganese chloride tetrahydrate and 3 parts by weight of 2-aminoterephthalic acid were dispersed in 300 parts by weight of a mixed solvent (V N,N-二甲基甲酰胺 :V 无水乙醇 :V 去离子水A mixture was obtained in a ratio of 15:1:1). 8 parts by weight of oxidized carbon fiber were dispersed in the above mixture, and the mixture was kept at 125 °C for 24 h for a solvothermal reaction. After the reaction, the modified carbon fiber was obtained by washing and drying.

[0043] Example 1: Preparation of an impact-resistant carbon fiber foam composite, comprising the following steps: The dried Chinese alpine rush was cut into 1 cm lengths, heated to 250 °C at a heating rate of 10 °C / min in a nitrogen protection environment and kept for 1 h. After the holding, it was alternately washed 3 times with absolute ethanol and deionized water, and dried at 60 °C for 8 h to obtain a carbon precursor; 10 parts by weight of the carbon precursor and 15 parts by weight of the binder prepared in Preparation Example 1 were dispersed in 100 parts by weight of absolute ethanol, and stirred at 60 °C for 12 h for a first impregnation reaction. After the reaction, 1 part by weight of the modified carbon fiber prepared in Preparation Example 7 and 0.15 part by weight of scandium trifluoromethanesulfonate were added, and stirred at 25 °C for 4 h for a second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it was dried at 90 °C for 6 h to obtain a precursor; the obtained precursor was heated to 1000 °C at a heating rate of 5 °C / min in a nitrogen protection environment and kept for 3 h for pyrolysis. After the reaction, it was cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 8 °C / min and then naturally cooled to obtain the impact-resistant carbon fiber foam composite.

[0044] Example 2: Preparation of an impact-resistant carbon fiber foam composite, comprising the following steps: The dried Chinese alpine rush was cut into 1 cm lengths, heated to 280 °C at a heating rate of 12 °C / min in a nitrogen protection environment and kept for 1.3 h. After the holding, it was alternately washed 3 times with absolute ethanol and deionized water, and dried at 62 °C for 9 h to obtain a carbon precursor; 12 parts by weight of the carbon precursor and 20 parts by weight of the binder prepared in Preparation Example 2 were dispersed in 100 parts by weight of absolute ethanol, and stirred at 62 °C for 15 h for a first impregnation reaction. After the reaction, 1.2 parts by weight of the modified carbon fiber prepared in Preparation Example 8 and 0.19 part by weight of scandium trifluoromethanesulfonate were added, and stirred at 26 °C for 4.5 h for a second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it was dried at 92 °C for 6.5 h to obtain a precursor; the obtained precursor was heated to 1200 °C at a heating rate of 5 °C / min in a nitrogen protection environment and kept for 3.5 h for pyrolysis. After the reaction, it was cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 8.5 °C / min and then naturally cooled to obtain the impact-resistant carbon fiber foam composite.

[0045] Example 3: Preparation of an impact-resistant carbon fiber foam composite, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 300 °C at a heating rate of 15 °C / min in a nitrogen protection environment, held for 1.8 h, and after the holding is completed, washed alternately with absolute ethanol and deionized water 3 times, and dried at 66 °C for 10 h to obtain a carbon precursor; 14 parts by weight of the carbon precursor and 25 parts by weight of the binder prepared in Preparation Example 3 are dispersed in 100 parts by weight of absolute ethanol, and a first impregnation reaction is carried out by stirring at 67 °C for 20 h. After the reaction is completed, 1.5 parts by weight of the modified carbon fiber prepared in Preparation Example 9 and 0.22 parts by weight of scandium trifluoromethanesulfonate are added, and a second impregnation reaction is carried out by stirring at 28 °C for 5 h. Subsequently, after centrifugal slurring and natural air drying, it is dried at 96 °C for 7 h to obtain a precursor; the obtained precursor is heated to 1400 °C at a heating rate of 5 °C / min in a nitrogen protection environment, held for 3.5 h for pyrolysis. After the reaction is completed, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 9 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0046] Example 4: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 350 °C at a heating rate of 15 °C / min in a nitrogen protection environment, held for 2 h, and after the holding is completed, washed alternately with absolute ethanol and deionized water 3 times, and dried at 70 °C for 12 h to obtain a carbon precursor; 15 parts by weight of the carbon precursor and 30 parts by weight of the binder prepared in Preparation Example 4 are dispersed in 100 parts by weight of absolute ethanol, and a first impregnation reaction is carried out by stirring at 70 °C for 24 h. After the reaction is completed, 2 parts by weight of the modified carbon fiber prepared in Preparation Example 10 and 0.25 parts by weight of scandium trifluoromethanesulfonate are added, and a second impregnation reaction is carried out by stirring at 30 °C for 6 h. Subsequently, after centrifugal slurring and natural air drying, it is dried at 100 °C for 8 h to obtain a precursor; the obtained precursor is heated to 1500 °C at a heating rate of 5 °C / min in a nitrogen protection environment, held for 4 h for pyrolysis. After the reaction is completed, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 10 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0047] Comparative Example 1: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 350 °C at a heating rate of 15 °C / min in a nitrogen protection environment, held for 2 h, and after the holding ends, it is alternately washed 3 times with absolute ethanol and deionized water, and dried at 70 °C for 12 h to obtain a carbon precursor; 15 parts by weight of the carbon precursor and 30 parts by weight of the binder prepared in Preparation Example 5 are dispersed in 100 parts by weight of absolute ethanol, and stirred at 70 °C for 24 h for the first impregnation reaction. After the reaction ends, 2 parts by weight of the modified carbon fiber prepared in Preparation Example 10 and 0.25 parts by weight of scandium trifluoromethanesulfonate are added and stirred at 30 °C for 6 h for the second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it is dried at 100 °C for 8 h to obtain a precursor; the above-obtained precursor is heated to 1500 °C at a heating rate of 5 °C / min in a nitrogen protection environment, held for 4 h for pyrolysis. After the reaction ends, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 10 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0048] Comparative Example 2: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 350 °C at a heating rate of 15 °C / min in a nitrogen protection environment, held for 2 h, and after the holding ends, it is alternately washed 3 times with absolute ethanol and deionized water, and dried at 70 °C for 12 h to obtain a carbon precursor; 15 parts by weight of the carbon precursor and 30 parts by weight of the binder prepared in Preparation Example 6 are dispersed in 100 parts by weight of absolute ethanol, and stirred at 70 °C for 24 h for the first impregnation reaction. After the reaction ends, 2 parts by weight of the modified carbon fiber prepared in Preparation Example 10 and 0.25 parts by weight of scandium trifluoromethanesulfonate are added and stirred at 30 °C for 6 h for the second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it is dried at 100 °C for 8 h to obtain a precursor; the above-obtained precursor is heated to 1500 °C at a heating rate of 5 °C / min in a nitrogen protection environment, held for 4 h for pyrolysis. After the reaction ends, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 10 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0049] Comparative Example 3: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 350 °C at a heating rate of 15 °C / min in a nitrogen protection environment and held for 2 h. After the holding is completed, it is alternately washed 3 times with absolute ethanol and deionized water, and dried at 70 °C for 12 h to obtain a carbon precursor; 15 parts by weight of the carbon precursor and 30 parts by weight of the binder prepared in Preparation Example 4 are dispersed in 100 parts by weight of absolute ethanol, and stirred at 70 °C for 24 h for the first impregnation reaction. After the reaction is completed, 2 parts by weight of the modified carbon fiber prepared in Preparation Example 11 and 0.25 parts by weight of scandium trifluoromethanesulfonate are added and stirred at 30 °C for 6 h for the second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it is dried at 100 °C for 8 h to obtain a precursor; the above-obtained precursor is heated to 1500 °C at a heating rate of 5 °C / min in a nitrogen protection environment and held for 4 h for pyrolysis. After the reaction is completed, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 10 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0050] Comparative Example 4: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 350 °C at a heating rate of 15 °C / min in a nitrogen protection environment and held for 2 h. After the holding is completed, it is alternately washed 3 times with absolute ethanol and deionized water, and dried at 70 °C for 12 h to obtain a carbon precursor; 15 parts by weight of the carbon precursor and 30 parts by weight of the binder prepared in Preparation Example 4 are dispersed in 100 parts by weight of absolute ethanol, and stirred at 70 °C for 24 h for the first impregnation reaction. After the reaction is completed, 2 parts by weight of the modified carbon fiber prepared in Preparation Example 12 and 0.25 parts by weight of scandium trifluoromethanesulfonate are added and stirred at 30 °C for 6 h for the second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it is dried at 100 °C for 8 h to obtain a precursor; the above-obtained precursor is heated to 1500 °C at a heating rate of 5 °C / min in a nitrogen protection environment and held for 4 h for pyrolysis. After the reaction is completed, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 10 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0051] Comparative Example 5: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 350 °C at a heating rate of 15 °C / min in a nitrogen protection environment and held for 2 h. After the holding is completed, it is alternately washed 3 times with absolute ethanol and deionized water, and dried at 70 °C for 12 h to obtain a carbon precursor; 15 parts by weight of the carbon precursor and 30 parts by weight of hexamethyldisilazane are dispersed in 100 parts by weight of absolute ethanol, and stirred at 70 °C for 24 h for the first impregnation reaction. After the reaction is completed, 2 parts by weight of the modified carbon fiber prepared in Preparation Example 12 and 0.25 parts by weight of scandium trifluoromethanesulfonate are added and stirred at 30 °C for 6 h for the second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it is dried at 100 °C for 8 h to obtain a precursor; the above-obtained precursor is heated to 1500 °C at a heating rate of 5 °C / min in a nitrogen protection environment and held for 4 h for pyrolysis. After the reaction is completed, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 10 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0052] Comparative Example 6: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is cut into lengths of 1 cm, heated to 350 °C at a heating rate of 15 °C / min in a nitrogen protection environment and held for 2 h. After the holding is completed, it is alternately washed 3 times with absolute ethanol and deionized water, and dried at 70 °C for 12 h to obtain a carbon precursor; 15 parts by weight of the carbon precursor and 30 parts by weight of the coupling agent prepared in Preparation Example 4 are dispersed in 100 parts by weight of absolute ethanol, and stirred at 70 °C for 24 h for the first impregnation reaction. After the reaction is completed, 2 parts by weight of short-cut carbon fibers and 0.25 parts by weight of scandium trifluoromethanesulfonate are added and stirred at 30 °C for 6 h for the second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, it is dried at 100 °C for 8 h to obtain a precursor; the above-obtained precursor is heated to 1500 °C at a heating rate of 5 °C / min in a nitrogen protection environment and held for 4 h for pyrolysis. After the reaction is completed, it is cooled to 800 °C at a cooling rate of 2 °C / min, and then cooled to 100 °C at a rate of 10 °C / min and then naturally cooled to obtain an impact-resistant carbon fiber foam composite material.

[0053] Comparative Example 7: Preparation of an impact-resistant carbon fiber foam composite material, comprising the following steps: The dry eulaliopsis binata is pulverized and sieved through a 80-mesh sieve to obtain eulaliopsis binata powder, and 30 parts by weight of the eulaliopsis binata powder is dispersed in 100 parts by weight of a mixed solvent (V 甲苯 :V 乙醇=2: 1) React at 80 °C for 8 h. After the reaction, obtain pretreated longan grass powder through suction filtration, washing, and drying; Disperse 20 parts by weight of the pretreated longan grass powder in 600 parts by weight of a mixed solution composed of sodium hydroxide and hydrogen peroxide (where the concentration of sodium hydroxide is 6% and the concentration of hydrogen peroxide is 0.7%). After ultrasonic treatment at 25 °C for 15 min, stir and react at 90 °C for 3 h. After the reaction, obtain alkali-treated longan grass through suction filtration, washing, and drying; Disperse the obtained alkali-treated longan grass in an acetic acid solution with a pH of 6.5 and stir and react at 70 °C for 4 h. After the reaction, obtain longan grass cellulose through suction filtration, washing, and drying; Disperse 15 parts by weight of longan grass cellulose and 30 parts by weight of the coupling agent prepared in Preparation Example 4 in 100 parts by weight of absolute ethanol, stir at 70 °C for 24 h for the first impregnation reaction. After the reaction, add 2 parts by weight of the modified carbon fiber prepared in Preparation Example 10 and 0.25 parts by weight of scandium trifluoromethanesulfonate, stir and react at 30 °C for 6 h for the second impregnation reaction. Subsequently, after centrifugal slurring and natural air drying, dry at 100 °C for 8 h to obtain a precursor; The obtained precursor is pyrolyzed in a nitrogen protection environment at a heating rate of 5 °C / min to 1500 °C and held for 4 h. After the reaction, cool to 800 °C at a cooling rate of 2 °C / min, and then cool to 100 °C at a rate of 10 °C / min and then cool naturally to obtain an impact-resistant carbon fiber foam composite material.

[0054] Comparative Example 8: Preparation of an impact-resistant carbon fiber foam composite material, including the following steps: 2 parts by weight of carbon fiber, 50 parts by weight of silicon carbide fine powder, 3 parts by weight of silicon dioxide fine powder, and 20 parts by weight of deionized water are ball-milled in a vacuum for 3 h to obtain a ceramic slurry. Immerse the polyurethane foam in the above ceramic slurry under vacuum conditions. After immersion, perform centrifugal slurring and natural air drying, and then dry at 100 °C for 8 h to obtain a precursor; The obtained precursor is pyrolyzed in a nitrogen protection environment at a heating rate of 5 °C / min to 1500 °C and held for 4 h. After the reaction, cool to 800 °C at a cooling rate of 2 °C / min, and then cool to 100 °C at a rate of 10 °C / min and then cool naturally to obtain an impact-resistant carbon fiber foam composite material.

[0055] Performance test: Impact resistance: Refer to the method of QB / T 1993 - 2012 to detect the impact resistance of the carbon fiber foam composite materials prepared in Examples 1 - 4 and Comparative Examples 1 - 8; Porosity: Refer to the method of GB / T 1966 - 1996 to detect the porosity of the carbon fiber foam composite materials prepared in Examples 1 - 4 and Comparative Examples 1 - 8; Thermal shock stability: The thermal shock stability of the carbon fiber foam composites prepared in Examples 1-4 and Comparative Examples 1-8 was determined by referring to the method of GB / T 30873-2014. The specific results are shown in Table 1.

[0056] It can be seen from the data in Table 1 that the carbon fiber foam composites prepared in Examples 1-4 have good impact strength, porosity and thermal shock stability compared with the carbon fiber foam composites prepared in Comparative Examples 1-8; the above data show that the present invention significantly improves the impact resistance of the carbon fiber foam ceramic composites by using the product after heat treatment of Chinese alpine rush as the carbon skeleton, introducing the binder, synthesizing Mg-MOF and connecting the modified carbon fibers. These operations work synergistically from three aspects of interface bonding, stress dispersion and structural stability, enabling the composite material to exhibit excellent mechanical properties under impact load; the introduction of Mg-MOF increases the porosity, while the cross-linked network of the binder and cellulose optimizes the pore distribution, making the voids of the composite material more uniform. The connection of the modified carbon fibers enhances the interfacial bonding strength between the fibers and the matrix, enabling the material to better resist the interfacial peeling caused by thermal stress during the thermal shock process.

[0057] The above embodiments have detailed the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A preparation process of an impact-resistant carbon fiber foam composite material, characterized in that, The preparation process includes the following steps: The Chinese alpine rush is pretreated to obtain a carbon precursor. The carbon precursor, a linker, and absolute ethanol are mixed to conduct a first impregnation reaction. After the reaction ends, modified carbon fibers and a first catalyst are added to conduct a second impregnation reaction to obtain a precursor, and the precursor is pyrolyzed to obtain the impact-resistant carbon fiber foam composite material.

2. The preparation process of an impact-resistant carbon fiber foam composite material as described in claim 1, characterized in that, The preparation method of the linker includes the following steps: Dicyandiamide, methyldichlorosilane, and a second catalyst are dispersed in n-hexane, and a stirring reaction is conducted in an inert gas protection environment to obtain the linker.

3. The preparation process of an impact-resistant carbon fiber foam composite material as described in claim 1, characterized in that, The preparation method of the modified carbon fibers includes the following steps: The chopped carbon fibers are sequentially subjected to desizing treatment and oxidation treatment to obtain oxidized carbon fibers. Magnesium nitrate hexahydrate and 2-aminoterephthalic acid are mixed with a mixed solvent to react to obtain a mixture. The oxidized carbon fibers are dispersed in the mixture and subjected to a solvothermal reaction to obtain the modified carbon fibers.

4. The preparation process of an impact-resistant carbon fiber foam composite material according to claim 2, wherein, The weight ratio of the dicyandiamide, methyldichlorosilane, and the second catalyst is 45-60:20-25:10-15.

5. The preparation process of an impact-resistant carbon fiber foam composite material as described in claim 2, characterized in that, The second catalyst is triethylamine.

6. The preparation process of an impact-resistant carbon fiber foam composite material as described in claim 3, characterized in that, The weight ratio of the magnesium nitrate hexahydrate and 2-aminoterephthalic acid is 10-15:2-3.

7. The preparation process of an impact-resistant carbon fiber foam composite material according to claim 3, characterized in that, The weight ratio of the magnesium nitrate hexahydrate and the oxidized carbon fibers is 10-15:5-8.

8. The preparation process of an impact-resistant carbon fiber foam composite material as described in claim 1, characterized in that, The weight ratio of the carbon precursor, the linker, and the modified carbon fibers is 10-15:3-5:1-2.

9. The preparation process of an impact-resistant carbon fiber foam composite material as described in claim 1, characterized in that, The weight ratio of the modified carbon fibers and the first catalyst is 1-2:0.15-0.

25.

10. The preparation process of an impact-resistant carbon fiber foam composite material as described in claim 1, characterized in that, The first catalyst is scandium trifluoromethanesulfonate.

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