Preparation method of carbon fiber / bismaleimide resin material as well as product and application of carbon fiber / bismaleimide resin material

Abstract

The invention discloses a preparation method of a carbon fiber / bismaleimide resin material as well as a product and application of the carbon fiber / bismaleimide resin material, and belongs to the technical field of composite materials. The preparation method comprises the following steps: preparing oxidized carbon fibers, preparing amino functionalized MXene, preparing diene functionalized MXene, preparing diene functionalized MXene grafted carbon fibers, and preparing the carbon fiber / bismaleimide resin composite material. The carbon fibers are subjected to surface grafting modification, and MXene and Diels-Alder bonds are introduced to the interface of the composite material, so that the interface strength of the composite material can be enhanced, meanwhile, the interface damage self-repairing function of the composite material is given, the mechanical property of the composite material can be remarkably improved, and the service life of the composite material is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, and particularly relates to a method for preparing carbon fiber / bismaleimide resin material, its products, and applications. Background Technology

[0002] Carbon fiber reinforced resin matrix composites, with their superior specific strength, specific modulus, and flexible designability, have become indispensable core materials in key fields such as aerospace, high-end equipment, and transportation. Their performance directly affects the reliability and service life of end products. However, the overall macroscopic properties of these composites are largely limited by the interfacial bonding effectiveness between carbon fibers and the resin matrix. The inherent characteristics of high chemical inertness and low surface energy of carbon fiber surfaces result in generally weak interfacial bond strength between them and the resin matrix, easily forming an interfacial transition layer with weak mechanical properties.

[0003] Under complex alternating loads and harsh service environments (such as temperature fluctuations and media erosion), microcracks are prone to initiation in the interfacial region. These microcracks propagate rapidly and trigger macroscopic delamination failure, ultimately leading to a sharp decline in the mechanical properties of the composite material and severely shortening the service life of the structural components. Therefore, how to simultaneously achieve interfacial strengthening and self-repair of interfacial damage has become a core technical challenge for improving the reliability of carbon fiber reinforced resin matrix composites and extending their service life.

[0004] To address the challenge of self-healing in composite materials, academia and industry have conducted extensive research. Among these efforts, self-healing systems based on reversible Diels-Alder bonds have shown significant application potential due to their mild reaction conditions, high reversibility, and controllability. This system achieves autonomous healing of microcracks by introducing furan and maleimide functional groups into the material and triggering a reversible bond breaking and rebonding reaction through thermal stimulation. However, in-depth research has revealed inherent defects in traditional self-healing systems that rely solely on Diels-Alder bonds. To ensure effective self-healing performance, Diels-Alder reaction units need to be integrated into flexible or dynamic molecular network structures. This typically requires introducing flexible segments or reducing the matrix crosslinking density, inevitably sacrificing the rigidity, strength, and thermal stability of the composite material.

[0005] The inherent contradiction between self-healing functionality and mechanical properties makes traditional Diels-Alder self-healing composites unable to meet the stringent high-performance requirements of primary load-bearing structural components, severely limiting their widespread application in core fields. Therefore, developing a new technology that can endow composite materials with efficient interfacial self-healing capabilities while avoiding mechanical property loss and even further improving the mechanical properties of the composite material itself and its interfaces has become a critical bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a method for preparing carbon fiber / bismaleimide resin materials, along with their products and applications. This method introduces MXene and Diels-Alder bonds into the composite material interface through surface grafting modification of carbon fibers, thereby enhancing the interfacial strength of the composite material and endowing it with self-healing capabilities for interfacial damage.

[0007] To achieve the above objectives, the present invention provides the following technical solution: One objective of this invention is to provide a method for preparing carbon fiber / bismaleimide resin material, comprising the following steps: Carbon fibers are oxidized to obtain oxidized carbon fibers; The silane coupling agent was dispersed in anhydrous ethanol and the pH was adjusted to acidic. An aqueous solution of MXene was added, and a first ultrasonic reaction was carried out. After cooling to room temperature, amino-functionalized MXene was obtained by centrifugation, washing, and drying. The amino-functionalized MXene was added to N,N'-dimethylformamide and ultrasonically dispersed evenly. Then, a carboxyl-containing diene and catalyst 1 were added, the mixture was heated to react, cooled to room temperature, and the diene-functionalized MXene was obtained after centrifugation, washing, and drying. The diene-functionalized MXene was pre-dispersed in N,N'-dimethylformamide, and then carbon oxidized carbon fiber and catalyst 2 were added. A second ultrasonic reaction was carried out, and after drying, diene-functionalized MXene grafted carbon fiber was obtained. Bismaleimide resin and diallyl bisphenol A were mixed, and then the diene-functionalized MXene grafted carbon fibers were added. After curing, carbon fiber / bismaleimide resin material was obtained.

[0008] This invention achieves two core advantages through a stepwise modification strategy: preparation of oxidized carbon fiber → preparation of amino-functionalized MXene → preparation of diene-functionalized MXene → preparation of grafted carbon fiber → resin composite curing. First, MXene is directionally introduced at the interface between the carbon fiber and the resin matrix. Utilizing MXene's high specific surface area and excellent mechanical properties, the interfacial bonding strength is significantly improved, solving the problem of insufficient interfacial bonding caused by the inertness of traditional carbon fiber surfaces. Second, furan functional groups are introduced through diene functionalization modification, forming Diels-Alder thermally reversible covalent bonds with bismaleimide resin. This endows the material with self-healing capabilities for interfacial damage, breaking through the bottleneck of traditional self-healing systems where "functionality and mechanical properties cannot be simultaneously achieved," ultimately realizing a synergistic effect of improved mechanical properties and extended service life of the composite material.

[0009] Further, the specific steps of the oxidation treatment include: removing the slurry on the surface of the carbon fiber with acetone, then acidifying it in a mixed acid at 60-100℃ for 4-8 hours, washing it until neutral and drying it to obtain oxidized carbon fiber; wherein the mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:(1-1.5).

[0010] This invention clarifies the specific parameters for carbon fiber oxidation treatment, and its beneficial effects are as follows: acetone cleaning can efficiently remove sizing agents from the carbon fiber surface, eliminating the sizing agents' obstruction of interfacial bonding; mixed acid acidification treatment can introduce a large number of oxygen-containing functional groups (such as hydroxyl and carboxyl groups) on the carbon fiber surface, while moderately roughening the surface, providing sufficient reaction sites for subsequent grafting of diene functionalized MXene; precise control of the mixed acid ratio and treatment conditions can avoid the loss of bulk strength caused by excessive oxidation of carbon fibers, achieving a balance between surface activity enhancement and bulk performance retention.

[0011] Furthermore, the silane coupling agent is selected from 3-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane.

[0012] The silane coupling agent selected in this invention has high reactivity and can efficiently bind to the hydroxyl groups on the surface of MXene to achieve amino functionalization.

[0013] Furthermore, the MXene is selected from Ti3C2T. X Ti2CTx or Ti3CNT X .

[0014] The MXene selected in this invention can meet the needs of composite material interface strengthening, and its excellent mechanical and thermal stability properties empower the interface.

[0015] Furthermore, the acid used to adjust the pH is acetic acid, hydrochloric acid, propionic acid, formic acid or oxalic acid, with a pH of 4-5; the mass ratio of the silane coupling agent to MXene is (1-4):1.

[0016] This invention limits the pH and specific raw material dosage, which can control the hydrolysis rate of the silane coupling agent and ensure that the silane coupling agent is uniformly grafted onto the MXene surface.

[0017] Furthermore, the specific operational steps of the first ultrasonic reaction include: reacting at 40-60℃ for 4-8 hours under ultrasonic conditions.

[0018] This invention specifies the ultrasonic treatment conditions, which can promote reaction uniformity, improve MXene functionalization efficiency, and lay the structural foundation for subsequent diene grafting.

[0019] Furthermore, the carboxyl-containing diene is selected from furanoic acid, 2-furanoacetic acid, or 3-(2-furan)propionic acid.

[0020] The carboxyl-containing diene type selected in this invention can achieve stable grafting of furan functional groups through amidation reaction between the carboxyl group and the amino group of amino-functionalized MXene, providing precise sites for the Diels-Alder reaction.

[0021] Further, the catalyst 1 is selected from dicyclohexylcarbodiimide, 2-(7-benzotriazole oxide)-N,N,N',N'-tetramethylurea hexafluorophosphate or O-benzotriazole-N,N,N',N'-tetramethylurea tetrafluoroboric acid.

[0022] The catalyst type 1 selected in this invention can efficiently catalyze the amidation reaction, reduce the activation energy of the reaction, and improve the functionalization conversion rate.

[0023] Further, the mass ratio of MXene, carboxyl-containing diene and catalyst 1 is 1:(1-1.5):(1-1.5); the specific operation steps of the heating reaction include: reacting at 120-140℃ for 4-8 hours under a nitrogen atmosphere.

[0024] The present invention limits the dosage ratio and heating reaction conditions to ensure that the reaction proceeds fully and avoids the residue of unreacted functional groups. At the same time, the nitrogen atmosphere can prevent MXene oxidation and functional group degradation, thus ensuring the structural stability of diene-functionalized MXene.

[0025] Further, the mass ratio of the diene-functionalized MXene, oxidized carbon fiber, and catalyst 2 is 1:(0.5-1):(0.5-1). Catalyst 2 is selected from dicyclohexylcarbodiimide, 2-(7-benzotriazole oxide)-N,N,N',N'-tetramethylurea hexafluorophosphate, or O-benzotriazole-N,N,N',N'-tetramethylurea tetrafluoroboric acid.

[0026] This invention regulates the mass ratio of diene-functionalized MXene, oxidized carbon fibers, and catalyst 2, enabling precise control of the MXene grafting density on the carbon fiber surface. This avoids agglomeration due to excessive grafting or insufficient interfacial reinforcement due to insufficient grafting. Reusing catalyst 1, the same type as in the previous step, ensures a consistent grafting reaction mechanism, improving process compatibility and product stability.

[0027] Furthermore, the specific steps of the second ultrasonic reaction include: reacting at 80-100℃ for 4-6 hours under ultrasonic conditions.

[0028] This invention utilizes the dispersing and reaction-promoting effects of ultrasound to uniformly graft MXene onto the surface of oxidized carbon fibers, forming a "carbon fiber-MXene" composite reinforcing phase, which further improves the mechanical properties of the interfacial transition layer.

[0029] Furthermore, the mass ratio of the bismaleimide resin to diallyl bisphenol A is 1:1.

[0030] This ratio achieves a precise balance between the rigidity and toughness of the resin system. Bismaleimide resin provides excellent thermal stability and rigidity, while diallyl bisphenol A, as a crosslinking agent and toughening agent, can improve the brittleness of the resin. The synergistic effect of the two can not only form a stable composite structure with diene-functionalized MXene grafted carbon fibers, but also provide a suitable molecular environment for the formation and reversible recombination of Diels-Alder bonds, avoiding the performance shortcomings caused by a single resin system.

[0031] Furthermore, the specific steps of the curing process include: pre-curing at 180-210℃ for 2-4 hours, and then curing at 230-250℃ for 2-4 hours.

[0032] This invention clarifies the two-step process parameters for curing. Pre-curing allows the resin system to slowly cross-link, gradually expelling air bubbles and low-molecular-weight volatiles, thus avoiding internal defects caused by rapid curing. Post-curing promotes complete cross-linking of the resin, forming a dense and stable three-dimensional network structure. Simultaneously, it ensures sufficient reaction between the diene and maleimide functional groups to form Diels-Alder bonds, optimizing the mechanical properties (such as tensile strength and flexural strength) and thermal stability of the composite material. The combination of curing temperature and time in the two steps matches the interfacial bonding rhythm of carbon fiber, MXene, and resin, improving the overall structural consistency of the composite material.

[0033] The second objective of this invention is to provide a carbon fiber / bismaleimide resin material, which is prepared by the above-described method.

[0034] The material prepared by this invention exhibits significantly improved interfacial strength, addressing the weakness of interfacial bonding in traditional carbon fiber / bismaleimide composites. Furthermore, this material possesses highly efficient self-healing capabilities, achieving an initial repair efficiency of 92.2% and maintaining a high repair efficiency of 88.5% even after five repairs. Mechanical properties and thermal stability are synergistically improved, avoiding the rigidity and strength losses caused by the introduction of flexible segments in traditional self-healing materials. The structure is stable and resistant to microcracks under complex alternating loads and harsh service environments (temperature fluctuations, media erosion, etc.), resulting in a significantly extended service life.

[0035] The third objective of this invention is to provide a method for repairing the interface of the above-mentioned carbon fiber / bismaleimide resin material, comprising the following steps: heating the damaged carbon fiber / bismaleimide resin material at 110-130°C for 1-3 hours, and then heating it at 60-70°C for 1-3 hours.

[0036] This invention defines a method for interfacial repair of materials. The repair conditions are mild: heating at 110-130℃ can efficiently trigger the breakage of Diels-Alder bonds, and heating at 60-70℃ promotes bond recombination, avoiding damage to the material's intrinsic properties caused by high temperatures. The repair process is simple and fast (total repair time for a single repair is 2-6 hours), requiring no complex equipment and reducing repair costs. The repair mechanism has strong reversibility, enabling multiple damage-repair cycles at the interface, solving the problem of difficult repair of interfacial damage in traditional composite materials, and further extending the service life of the material.

[0037] The fourth objective of this invention is to provide applications of carbon fiber / bismaleimide resin materials in the aerospace, high-end equipment, or transportation fields.

[0038] This invention clarifies the application areas of the material, and its beneficial effects are highly compatible with the stringent requirements of the application scenarios: ① In the aerospace field, the material's high specific strength, high interfacial strength, and self-healing function can improve the reliability of aircraft structural components and reduce the risk of failure in high-altitude and high-temperature environments; ② In the high-end equipment field, it can meet the stringent requirements of core components for mechanical performance and long service life, reducing maintenance frequency and costs; ③ In the transportation field, it can improve the fatigue resistance and durability of vehicle and rail transit structural components, adapting to complex road conditions and environmental erosion; ④ The material's performance advantages fill the gap in the demand for high-performance + self-healing composite materials in high-end fields, promoting the large-scale application of composite materials in key areas.

[0039] Compared with the prior art, the present invention has the following advantages and technical effects: 1) This invention introduces MXene at the interface between carbon fiber and bismaleimide resin matrix through chemical grafting, which can effectively improve the interfacial strength of composite materials. 2) This invention forms thermally reversible covalent bonds at the interface of composite materials through the Diels-Alder reaction. After the interface of the composite materials is damaged, the breaking and recombination of Diels-Alder bonds can be controlled under mild conditions to achieve efficient self-repair of the interface, with an initial repair efficiency of up to 92.2%. 3) This invention can achieve multiple self-repairs of the interface, and the repair efficiency is still as high as 88.5% after five repairs; 4) The repair method of the present invention requires a low temperature, has simple repair conditions, fast repair speed, and low repair cost. Attached Figure Description

[0040] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1Infrared spectra of unmodified carbon fiber (Comparative Example 1) and diene-functionalized MXene-grafted carbon fiber (Example 1); Figure 2 The interfacial shear strength diagrams are for the materials prepared in Examples 1-3 and Comparative Example 1. Figure 3 The diagram shows the interface self-healing efficiency of the materials prepared in Examples 1-3 and Comparative Example 1. Figure 4 The diagram shows the efficiency of the interface self-healing of the material prepared in Example 1 after five cycles. Detailed Implementation

[0041] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0042] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0043] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0044] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0045] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0046] This invention discloses a method for preparing a carbon fiber / bismaleimide resin composite material with high strength and a self-healing interface. The steps include: preparing oxidized carbon fiber, preparing amino-functionalized MXene, preparing diene-functionalized MXene, preparing diene-functionalized MXene grafted onto carbon fiber, and obtaining the carbon fiber / bismaleimide resin composite material. This invention, by surface grafting modification of carbon fiber, introduces MXene and Diels-Alder bonds at the interface of the composite material, which can enhance the interfacial strength of the composite material and endow it with self-healing function for interfacial damage, significantly improving the mechanical properties of the composite material and extending its service life. The specific technical solution is as follows: S1. Preparation of oxidized carbon fiber: The carbon fiber is cleaned with acetone to remove the sizing agent on its surface; then the treated carbon fiber is placed in a mixed acid and acidified at 60-100℃ (e.g., 60℃ or 100℃) for 4-8 hours (e.g., 4 hours, 6 hours or 8 hours), wherein the mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:(1-1.5) (e.g., 1:1 or 1:1.5); after acidification, the carbon fiber is cleaned until neutral and dried to obtain oxidized carbon fiber; S2. Preparation of amino-functionalized MXene: 3-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane is selected as the silane coupling agent and dispersed in anhydrous ethanol; acetic acid, hydrochloric acid, propionic acid, formic acid or oxalic acid (for example, formic acid, acetic acid or hydrochloric acid are selected) are added to adjust the pH of the solution to 4-5 (e.g., pH=4 or pH=5), and then an aqueous solution of Ti3C2TX, Ti2CTx or Ti3CNTX type MXene is added, wherein the mass ratio of silane coupling agent to MXene is (1-4):1 (e.g., 2:1, 3:1 or 4:1); under ultrasonic conditions, the first ultrasonic reaction is carried out at 40-60℃ (e.g., 40℃, 50℃ or 60℃) for 4-8h (e.g., 4h, 6h or 8h). After the reaction is completed, the mixture is cooled to room temperature, centrifuged, washed and dried to obtain amino-functionalized MXene; S3. Preparation of diene-functionalized MXene: The amino-functionalized MXene obtained in step S2 was added to N,N'-dimethylformamide and ultrasonically treated until uniformly dispersed; furanoic acid, 2-furanoacetic acid, or 3-(2-furan)propionic acid were added as carboxyl-containing dienes, and dicyclohexylcarbodiimide, 2-(7-benzotriazole oxide)-N,N,N',N'-tetramethylurea hexafluorophosphate, or O-benzotriazole-N,N,N',N'-tetramethylurea tetrafluoroboric acid were added as... Catalyst 1 is used, wherein the mass ratio of amino-functionalized MXene, carboxyl-containing diene and catalyst 1 is 1:(1-1.5):(1-1.5) (e.g., 1:1.5:1, 1:1:1.5 or 1:1.5:1.5); under a nitrogen atmosphere, the reaction is heated at 120-140℃ (e.g., 120℃, 130℃ or 140℃) for 4-8h (e.g., 4h, 6h or 8h), and after cooling to room temperature, the diene-functionalized MXene is obtained by centrifugation, washing and drying. S4. Preparation of diene-functionalized MXene grafted carbon fibers: The diene-functionalized MXene obtained in step S3 is pre-dispersed in N,N'-dimethylformamide, and the carbon oxide obtained in step S1 and catalyst 2 of the same type as in step S3 are added, wherein the mass ratio of diene-functionalized MXene, carbon oxide and catalyst 2 is 1:(0.5-1):(0.5-1) (e.g. 1:0.5:0.5 or 1:1:1); Under ultrasonic conditions, a second ultrasonic reaction is carried out at 80-100℃ (e.g. 80℃, 90℃, 100℃) for 4-6h (e.g. 4h, 5h or 6h). After the reaction is completed, the carbon fibers are dried to obtain diene-functionalized MXene grafted carbon fibers. S5. Preparation of carbon fiber / bismaleimide resin material: Bismaleimide resin and diallyl bisphenol A are mixed uniformly at a mass ratio of 1:1 to obtain a resin mixture system; the diene functionalized MXene grafted carbon fiber obtained in step S4 is added to the system, and after uniform mixing, it is cured. First, it is pre-cured at 180-210℃ (e.g., 180℃, 190℃ or 200℃) for 2-4 hours (e.g., 3 hours or 4 hours), and then cured at 230-250℃ (e.g., 230℃ or 240℃) for 2-4 hours (e.g., 3 hours or 4 hours) to finally obtain carbon fiber / bismaleimide resin material.

[0047] S6. Interface repair steps for carbon fiber / bismaleimide resin materials: When the interface of the carbon fiber / bismaleimide resin material prepared above is damaged, the damaged material is first heated at 110-130℃ (e.g., 110℃, 120℃ or 130℃) for 1-3 hours (e.g., 1 hour or 3 hours), and then heated at 60-70℃ (e.g., 60℃, 65℃ or 70℃) for 1-3 hours (e.g., 1 hour or 3 hours) to achieve self-repair of the interface damage.

[0048] The carbon fiber / bismaleimide resin material prepared by the above method can be applied in the aerospace, high-end equipment, or transportation fields.

[0049] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0050] All raw materials used in this invention were purchased from the market.

[0051] The technical solution of the present invention will be further illustrated by the following embodiments.

[0052] Example 1 A method for preparing a carbon fiber / bismaleimide resin material, comprising the following steps: S1. Preparation of oxidized carbon fiber: The carbon fiber was cleaned with acetone to remove the sizing agent on its surface; then the treated carbon fiber was placed in a mixed acid and acidified at 100°C for 4 hours. The mixed acid was prepared by mixing concentrated sulfuric acid (concentration of 18 mol / L, the same below) and concentrated nitric acid (concentration of 16 mol / L, the same below) in a volume ratio of 1:1. After acidification, the carbon fiber was cleaned until neutral and dried to obtain oxidized carbon fiber. S2. Preparation of amino-functionalized MXene: 3-aminopropyltriethoxysilane was selected as the silane coupling agent and dispersed in anhydrous ethanol; hydrochloric acid was added to adjust the pH of the solution to 4, and then Ti3C2TX-type MXene aqueous solution was added, wherein the mass ratio of silane coupling agent to MXene was 3:1, and the volume ratio of silane coupling agent to anhydrous ethanol was 1 g:50 mL; under ultrasonic conditions, the first ultrasonic reaction was carried out at 60℃ for 4 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, washed, and dried to obtain amino-functionalized MXene. S3. Preparation of diene-functionalized MXene: The amino-functionalized MXene obtained in step S2 was added to N,N'-dimethylformamide and ultrasonically treated until uniformly dispersed; 2-furanacetic acid was added as a carboxyl-containing diene and dicyclohexylcarbodiimide as catalyst 1, wherein the mass ratio of amino-functionalized MXene, carboxyl-containing diene and catalyst 1 was 1:1.5:1, and the molar ratio of amino-functionalized MXene to N,N'-dimethylformamide was 1 g:80 mL; under a nitrogen atmosphere, the reaction was heated at 140 °C for 4 h, cooled to room temperature, and then centrifuged, washed and dried to obtain diene-functionalized MXene; S4. Preparation of diene-functionalized MXene grafted carbon fibers: The diene-functionalized MXene obtained in step S3 was pre-dispersed in N,N'-dimethylformamide (the ratio of diene-functionalized MXene to N,N'-dimethylformamide was 1 g: 100 mL), and the oxidized carbon fibers obtained in step S1 and catalyst 2 (dicyclohexylcarbodiimide) of the same type as in step S3 were added, wherein the mass ratio of diene-functionalized MXene, oxidized carbon fibers and catalyst 2 was 1:0.5:0.5; under ultrasonic conditions, a second ultrasonic reaction was carried out at 80℃ for 6 h, and after the reaction was completed, the fibers were dried to obtain diene-functionalized MXene grafted carbon fibers. S5. Preparation of carbon fiber / bismaleimide resin material: Bismaleimide resin and diallyl bisphenol A are mixed uniformly at a mass ratio of 1:1 to obtain a resin mixture system; the diene-functionalized MXene grafted carbon fiber obtained in step S4 is added to the system (the mass ratio of diene-functionalized MXene grafted carbon fiber to the resin mixture system is 10:8), and after uniform mixing, it is cured. It is first pre-cured at 200℃ for 3 hours, and then cured at 240℃ for 3 hours to finally obtain the carbon fiber / bismaleimide resin material.

[0053] When the interface of the carbon fiber / bismaleimide resin material prepared above is damaged, the damaged material can be heated at 120°C for 1 hour and then at 65°C for 1 hour to achieve self-repair of the interface damage.

[0054] Example 2 A method for preparing a carbon fiber / bismaleimide resin material, comprising the following steps: S1. Preparation of oxidized carbon fiber: The carbon fiber is cleaned with acetone to remove the sizing agent on its surface; then the treated carbon fiber is placed in a mixed acid and acidified at 100°C for 4 hours, wherein the mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:1.5; after acidification, the carbon fiber is cleaned until neutral and dried to obtain oxidized carbon fiber. S2. Preparation of amino-functionalized MXene: 3-aminopropyltrimethoxysilane was selected as the silane coupling agent and dispersed in anhydrous ethanol; acetic acid was added to adjust the pH of the solution to 5, and then Ti2CTx type MXene aqueous solution was added, wherein the mass ratio of silane coupling agent to MXene was 4:1, and the volume ratio of silane coupling agent to anhydrous ethanol was 1g:50mL; under ultrasonic conditions, the first ultrasonic reaction was carried out at 50℃ for 6h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, washed, and dried to obtain amino-functionalized MXene. S3. Preparation of diene-functionalized MXene: The amino-functionalized MXene obtained in step S2 was added to N,N'-dimethylformamide and ultrasonically treated until uniformly dispersed; furanyl carboxylic acid was added as a carboxyl-containing diene, and 2-(7-benzotriazole oxide)-N,N,N',N'-tetramethylurea hexafluorophosphate was added as catalyst 1, wherein the mass ratio of amino-functionalized MXene, carboxyl-containing diene and catalyst 1 was 1:1:1.5, and the molar ratio of amino-functionalized MXene to N,N'-dimethylformamide was 1 g:80 mL; under a nitrogen atmosphere, the reaction was heated at 120 °C for 6 h, cooled to room temperature, and then centrifuged, washed and dried to obtain diene-functionalized MXene; S4. Preparation of diene-functionalized MXene grafted carbon fibers: The diene-functionalized MXene obtained in step S3 was pre-dispersed in N,N'-dimethylformamide (the ratio of diene-functionalized MXene to N,N'-dimethylformamide was 1 g: 100 mL), and the carbon oxide obtained in step S1 and catalyst 2 (2-(7-benzotriazole oxide)-N,N,N',N'-tetramethylurea hexafluorophosphate) of the same type as in step S3 were added, wherein the mass ratio of diene-functionalized MXene, carbon oxide and catalyst 2 was 1:1:1; under ultrasonic conditions, a second ultrasonic reaction was carried out at 100℃ for 4 h, and after the reaction was completed, the carbon fibers were dried to obtain diene-functionalized MXene grafted carbon fibers. S5. Preparation of carbon fiber / bismaleimide resin material: Bismaleimide resin and diallyl bisphenol A are mixed uniformly at a mass ratio of 1:1 to obtain a resin mixture system; the diene-functionalized MXene grafted carbon fiber obtained in step S4 is added to the system (the mass ratio of diene-functionalized MXene grafted carbon fiber to the resin mixture system is 10:8), and after uniform mixing, it is cured. It is first pre-cured at 180℃ for 4 hours, and then cured at 230℃ for 4 hours to finally obtain the carbon fiber / bismaleimide resin material.

[0055] When the interface of the carbon fiber / bismaleimide resin material prepared above is damaged, the damaged material can be heated at 110°C for 3 hours and then at 60°C for 3 hours to achieve self-repair of the interface damage.

[0056] Example 3 A method for preparing a carbon fiber / bismaleimide resin material, comprising the following steps: S1. Preparation of oxidized carbon fiber: The carbon fiber is cleaned with acetone to remove the sizing agent on its surface; then the treated carbon fiber is placed in a mixed acid and acidified at 60°C for 8 hours, wherein the mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:1; after acidification, the carbon fiber is cleaned until neutral and dried to obtain oxidized carbon fiber. S2. Preparation of amino-functionalized MXene: 3-aminopropyltriethoxysilane was selected as the silane coupling agent and dispersed in anhydrous ethanol; formic acid was added to adjust the pH of the solution to 5, and then Ti3CNTX type MXene aqueous solution was added, wherein the mass ratio of silane coupling agent to MXene was 2:1, and the volume ratio of silane coupling agent to anhydrous ethanol was 1 g:50 mL; under ultrasonic conditions, the first ultrasonic reaction was carried out at 40℃ for 8 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, washed, and dried to obtain amino-functionalized MXene. S3. Preparation of diene-functionalized MXene: The amino-functionalized MXene obtained in step S2 was added to N,N'-dimethylformamide and ultrasonically treated until uniformly dispersed; 3-(2-furan)propionic acid was added as a carboxyl-containing diene, and O-benzotriazole-N,N,N',N'-tetramethylurea tetrafluoroboric acid was added as catalyst 1, wherein the mass ratio of amino-functionalized MXene, carboxyl-containing diene and catalyst 1 was 1:1.5:1.5, and the molar ratio of amino-functionalized MXene and N,N'-dimethylformamide was 1g:80mL; under a nitrogen atmosphere, the reaction was heated at 130℃ for 6h, cooled to room temperature, and then centrifuged, washed and dried to obtain diene-functionalized MXene; S4. Preparation of diene-functionalized MXene grafted carbon fibers: The diene-functionalized MXene obtained in step S3 was pre-dispersed in N,N'-dimethylformamide (the ratio of diene-functionalized MXene to N,N'-dimethylformamide was 1 g: 100 mL), and the carbon oxide obtained in step S1 and catalyst 2 (O-benzotriazole-N,N,N',N'-tetramethylurea tetrafluoroboric acid) of the same type as in step S3 were added, wherein the mass ratio of diene-functionalized MXene, carbon oxide and catalyst 2 was 1:1:1; under ultrasonic conditions, a second ultrasonic reaction was carried out at 90℃ for 5 h, and after the reaction was completed, the carbon fibers were dried to obtain diene-functionalized MXene grafted carbon fibers. S5. Preparation of carbon fiber / bismaleimide resin material: Bismaleimide resin and diallyl bisphenol A are mixed uniformly at a mass ratio of 1:1 to obtain a resin mixture system; the diene-functionalized MXene grafted carbon fiber obtained in step S4 is added to the system (the mass ratio of diene-functionalized MXene grafted carbon fiber to the resin mixture system is 10:8), and after uniform mixing, it is cured. It is first pre-cured at 190℃ for 3 hours, and then cured at 240℃ for 3 hours to finally obtain the carbon fiber / bismaleimide resin material.

[0057] When the interface of the carbon fiber / bismaleimide resin material prepared above is damaged, the damaged material can be heated at 130°C for 1 hour and then at 70°C for 1 hour to achieve self-repair of the interface damage.

[0058] Comparative Example 1 Bismaleimide resin and diallyl bisphenol A were mixed uniformly at a mass ratio of 1:1 to obtain a resin mixture system. Unmodified carbon fibers (the mass ratio of unmodified carbon fibers to the resin mixture system was 10:8) were added to the system, and after uniform mixing, the mixture was cured. It was first pre-cured at 200℃ for 3 hours, and then cured at 240℃ for 3 hours to finally obtain the material.

[0059] When the interface of the above materials is damaged, the damaged material can be heated at 120°C for 1 hour and then at 65°C for 1 hour to achieve self-repair of the interface damage.

[0060] Figure 1 The infrared spectra of unmodified carbon fiber (Comparative Example 1) and diene-functionalized MXene-grafted carbon fiber (Example 1) are shown below. Figure 1 As can be seen from the infrared spectrum, the diene-functionalized MXene-grafted carbon fibers prepared in Example 1 exhibit characteristic absorption peaks of MXene-related functional groups (such as Ti-O and C-Ti bonds) and diene-specific functional groups (furan rings); while Comparative Example 1 did not show the above characteristic peaks. This proves that the present invention successfully introduces MXene and furan groups into the surface of carbon fibers through chemical grafting, and the modification process effectively achieves the target functionalization modification.

[0061] Figure 2 The interfacial shear strength diagrams are for the materials prepared in Examples 1-3 and Comparative Example 1. Figure 2 As can be seen, compared with Comparative Example 1, the interfacial shear strength of the materials prepared in Examples 1-3 is significantly improved. Among them, the interfacial shear strength of Example 1 is 108.3% higher than that of Comparative Example 1, which proves that the interfacial properties of the composite material are significantly improved after the carbon fiber is surface modified.

[0062] Figure 3 The diagram shows the interface self-healing efficiency of the materials prepared in Examples 1-3 and Comparative Example 1. Figure 3 As can be seen, the interfacial self-healing efficiency (initial repair efficiency) of the materials prepared in Examples 1-3 is significantly higher than that of Comparative Example 1. Example 1 exhibits an initial repair efficiency as high as 92.2%, while Comparative Example 1 shows almost no effective self-healing ability or extremely low repair efficiency. This demonstrates that the present invention successfully endows the composite material with efficient interfacial self-healing function by introducing Diels-Alder thermally reversible covalent bonds at the interface. In contrast, the unmodified carbon fiber-resin matrix interface lacks reversible interaction sites and cannot achieve damage repair.

[0063] Figure 4 The diagram shows the efficiency of the interface self-healing of the material prepared in Example 1 after five cycles. Figure 4As can be seen, after five interface damage-repair cycles, the self-healing efficiency of the material in Example 1 remained at a high level of 88.5%, with a small decrease in repair efficiency. This indicates that the Diels-Alder self-healing system constructed in this invention has good reversibility and stability, enabling multiple efficient interface repairs. It overcomes the limitation of some self-healing materials experiencing significant performance degradation after a single repair, thus extending the service life of the material.

[0064] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for producing a carbon fiber / bismaleimide resin material, characterized by, The method comprises the following steps: oxidizing carbon fibers to obtain oxidized carbon fibers; dispersing a silane coupling agent into anhydrous ethanol and adjusting the pH to be acidic, adding an aqueous MXene solution, performing a first ultrasonic reaction, cooling to room temperature, and obtaining amino-functionalized MXene after centrifugation, washing, and drying; adding the amino-functionalized MXene into N,N'-dimethylformamide, uniformly dispersing under ultrasonic, then adding a carboxyl-containing diene and a catalyst 1, heating and reacting, cooling to room temperature, and obtaining diene-functionalized MXene after centrifugation, washing, and drying; pre-dispersing the diene-functionalized MXene in N,N'-dimethylformamide, then adding the oxidized carbon fibers and a catalyst 2, performing a second ultrasonic reaction, and obtaining diene-functionalized MXene grafted carbon fibers after drying; mixing a bismaleimide resin and a diallyl bisphenol A, then adding the diene-functionalized MXene grafted carbon fibers, and performing curing treatment to obtain a carbon fiber / bismaleimide resin material.

2. The production method according to claim 1, characterized by, The specific operation steps of the oxidation treatment include: removing the sizing agent on the surface of the carbon fibers using acetone, then performing acidification treatment in mixed acid at 60-100 DEG C for 4-8 h, washing to neutral, and drying to obtain the oxidized carbon fibers; wherein the mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1: (1-1.5).

3. The preparation method according to claim 1, characterized in that, The silane coupling agent is selected from 3-aminopropyl triethoxysilane or 3-aminopropyl trimethoxysilane; and / or, The MXene is selected from Ti3C2T X , Ti2CTx, or Ti3CNT X ; and / or, The acid used for adjusting the pH is acetic acid, hydrochloric acid, propionic acid, formic acid, or oxalic acid, and the pH is 4-5; and / or, The mass ratio of the silane coupling agent to the MXene is (1-4): 1; and / or, The specific operation steps of the first ultrasonic reaction include: reacting at 40-60 DEG C for 4-8 h under ultrasonic conditions.

4. The method of claim 1, wherein, The carboxyl-containing diene is selected from furan carboxylic acid, 2-furanacetic acid, or 3-(2-furan) propionic acid; and / or, The catalyst 1 is selected from dicyclohexyl carbodiimide, 2-(7-oxobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate, or O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroborate; and / or, The mass ratio of the MXene, the carboxyl-containing diene, and the catalyst 1 is 1: (1-1.5): (1-1.5); and / or, The specific operation steps of the heating reaction include: reacting at 120-140 DEG C for 4-8 h under a nitrogen atmosphere.

5. The preparation method according to claim 1, characterized in that, The mass ratio of the diene-functionalized MXene, the oxidized carbon fibers, and the catalyst 2 is 1: (0.5-1): (0.5-1); and / or, The catalyst 2 is selected from dicyclohexyl carbodiimide, 2-(7-oxobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate, or O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroborate; and / or, The specific operation steps of the second ultrasonic reaction include: reacting at 80-100 DEG C for 4-6 h under ultrasonic conditions.

6. The method of claim 1, wherein, The mass ratio of the bismaleimide resin to the diallyl bisphenol A is 1:

1.

7. The preparation method according to claim 1, characterized in that, The specific operation steps of the curing treatment include: pre-curing at 180-210°C for 2-4h, and then curing at 230-250°C for 2-4h.

8. A carbon fiber / bismaleimide resin material, characterized by, which is prepared by the method of any one of claims 1-7.

9. A method of interfacial repair of carbon fiber / bismaleimide resin materials as claimed in claim 8, characterized by, comprising the steps of: heating the damaged carbon fiber / bismaleimide resin material at 110-130°C for 1-3h, and then heating at 60-70°C for 1-3h.

10. Use of the carbon fiber / bismaleimide resin material according to claim 8 in the field of aerospace, high-end equipment or transportation.

Images