Interface enhanced carbon fiber composite material with high temperature damage monitoring function and preparation method and application thereof

Abstract

This invention discloses an interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, its preparation method, and its application. This invention directly induces in-situ nucleation and growth of organic ligands on the carbon fiber surface. By using different solvents and controlling the addition method and proportion of different solvents, explosive homogeneous nucleation is avoided, ensuring heterogeneous growth and orderly arrangement of hydrogen-bonded organic frameworks on the carbon fiber surface. This improves the high-temperature damage monitoring sensitivity and interface properties of the carbon fiber composite material.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, and in particular relates to interface-reinforced carbon fiber composite materials with high-temperature damage monitoring function, their preparation methods and applications. Background Technology

[0002] The demand for carbon fiber composites in high-temperature environments is increasing daily. When subjected to dynamic or static overloads in long-term thermo-oxidative environments, they are prone to microscopic damage such as fiber breakage or interfacial debonding. In addition to the increasing heat resistance requirements of the resin matrix itself, the temperature resistance level of the interface has a significant impact on the overall heat resistance of the composite material. Therefore, improving the high-temperature stability of the composite material interface and the sensitivity of damage monitoring at high temperatures is crucial.

[0003] Existing technologies utilize aromatic fused-ring molecules with fluorescence effects via π π-noncovalent interactions dominate the deposition on the carbon fiber surface, constructing a molecular assembly interface phase with high-temperature resistance and fluorescence properties without affecting the fiber's bulk properties. However, this method has the following problems: on the one hand, due to the strong π-noncovalent interactions... The tendency of π-packing in aromatic fused-ring molecules leads to fluorescence self-quenching in the solid or aggregated state, resulting in a significant decrease in fluorescence quantum yield and limiting their sensitivity in damage monitoring. Furthermore, when the temperature rises above 200℃, π-packing... π stacking is easily weakened by the intensification of molecular thermal motion, leading to the destruction of the interfacial layer structure and a significant decrease in fluorescence intensity. At high temperatures, the interfacial bonding and damage monitoring sensitivity of composite materials cannot achieve the desired effect.

[0004] Therefore, there is an urgent need to develop a carbon fiber composite material with high sensitivity for high-temperature damage monitoring, high interfacial bonding strength, and excellent high-temperature stability. Summary of the Invention

[0005] To address at least some of the technical problems in the prior art, this invention provides an interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, its preparation method, and its applications. Specifically, this invention includes the following:

[0006] A first aspect of the present invention provides a method for preparing an interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, comprising the following steps: (1) React aromatic rigid scaffolds and hydrogen bond synthons in a high-boiling-point organic solvent at a microwave power of 300-900 W for 5-15 min to obtain organic ligands; (2) Mix the first solvent and the organic ligand to obtain a first solution, impregnate the unsized carbon fiber with the first solution for 10-30 min, inject the second solvent in several batches and keep it at 50-80℃ for 0.5-4 h after each injection, and evaporate it at 80-120℃ for 12-72 h to obtain carbon fiber modified with hydrogen bonded organic framework, wherein the second solvent is injected 2-4 times; (3) The hydrogen-bonded organic framework modified carbon fiber is combined with a high-temperature resistant resin system and cured to obtain the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function.

[0007] In some embodiments, according to the method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, in step (1), the molar ratio of the aromatic rigid scaffold and the hydrogen bond synthon is 1:(10-20).

[0008] In some embodiments, according to the method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, in step (1), the aromatic rigid scaffolding comprises 1, 4, 5, 8 The hydrogen-bonded synthon comprises at least one of naphthalenetetracarboxylic dianhydride, 1,6,7,8-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, and biphenyltetracarboxylic dianhydride, wherein the hydrogen-bonded synthon comprises at least one of diaminotriazine, 5-aminoisophthalic acid, and 1,3,5-tris(4-aminophenyl)benzene, and the high-boiling organic solvent comprises at least one of propionic acid, ethylene glycol, and N-methylpyrrolidone.

[0009] In some embodiments, according to the method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, in step (2), the volume ratio of the cumulative injected amount of the first solvent to the second solvent is 1:(1-4).

[0010] In some embodiments, according to the method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, in step (2), the mass of the hydrogen-bonded organic framework modified layer is 1-2 wt% of the carbon fiber.

[0011] In some embodiments, according to the method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, the first solvent includes at least one of N,N-dimethylacetamide, N-methylpyrrolidone and N,N-dimethylformamide, and the second solvent includes at least one of 1,2,4-trichlorobenzene, 1,2-dichlorobenzene, 1,4-dioxane and xylene.

[0012] In some embodiments, according to the method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, the carbon fiber includes at least one of high-strength intermediate-modulus carbon fiber, high-strength high-modulus carbon fiber, and high-strength high-modulus high-toughness carbon fiber.

[0013] In some embodiments, according to the method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, the high-temperature resistant resin system includes a high-temperature resistant epoxy resin and a curing agent.

[0014] In some embodiments, according to the method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention, the epoxy resin includes at least one of glycidyl amine, epoxidized olefins and alicyclic epoxy resins, and the curing agent includes at least one of aromatic amines, alicyclic polyamines and acid anhydrides.

[0015] In a second aspect, the present invention provides an interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, which is obtained by the preparation method described in the present invention.

[0016] A third aspect of the present invention provides the application of the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention in high-temperature resistant composite materials.

[0017] The beneficial effects of this invention include: (1) This invention directly induces in-situ nucleation and growth of organic ligands on the carbon fiber surface. By using different solvents for treatment and controlling the addition method and ratio of different solvents, explosive homogeneous nucleation is avoided, ensuring that the hydrogen bonded organic framework grows heterogeneously and is arranged in an orderly manner on the carbon fiber surface, forming a crystalline hydrogen bonded organic framework with hydrogen bond network as the backbone and π-π stacking synergistic stability.

[0018] (2) This invention utilizes hydrogen-bonded organic framework to modify carbon fibers, which increases the surface activity and roughness of carbon fibers, enhances the chemical bonding and mechanical interlocking between carbon fibers and resin, facilitates uniform stress transfer, and significantly improves the interfacial bonding strength and high-temperature stability of carbon fiber epoxy composite materials.

[0019] (3) This invention prepares carbon fiber composite materials by combining hydrogen-bonded organic framework modified carbon fibers with epoxy resin. Due to the excellent thermal stability of the hydrogen-bonded organic framework, its hydrogen bond network can still maintain high bond energy at temperatures exceeding 200°C, undergoing only controllable structural evolution (including hydrogen bond network rearrangement, partial breakage, framework shrinkage or expansion, etc.) without causing significant damage to the interface layer structure. When the composite material is subjected to shear load at high temperature, the fluorescence signal of the interface layer in the damaged area is significantly weakened or disappears due to local breakage of the hydrogen bond network. The damaged area can be clearly identified by confocal laser scanning microscopy. Attached Figure Description

[0020] Figure 1 The infrared spectra of carbon fibers from embodiments of the present invention and Comparative Example 1 are shown.

[0021] Figure 2 The surface morphology of the hydrogen-bonded organic framework modified carbon fiber according to an embodiment of the present invention is shown at 25°C.

[0022] Figure 3 The surface morphology of the carbon fiber of Comparative Example 2 of the present invention at 25°C is shown.

[0023] Figure 4 The surface morphology of the hydrogen-bonded organic framework modified carbon fiber according to an embodiment of the present invention is shown at 220°C.

[0024] Figure 5 The interfacial shear strength of the composite materials of the embodiments and comparative examples of the present invention at 25°C and 220°C is shown.

[0025] Figure 6 The interfacial shear strength retention rates of the composite materials of the embodiments and comparative examples of the present invention at 220°C are shown.

[0026] Figure 7 A laser confocal micrograph of carbon fiber at 220°C, according to an embodiment of the present invention, is shown.

[0027] Figure 8 The image shown is a laser confocal micrograph of the carbon fiber of Comparative Example 1 of the present invention at 220°C.

[0028] Figure 9 The image shown is a laser confocal micrograph of the carbon fiber of Comparative Example 3 of the present invention at 220°C.

[0029] Figure 10 Image A shows a laser confocal micrograph of the composite material of the present invention before micro-debonding at 220°C, and image B shows a laser confocal micrograph of the composite material of the present invention after micro-debonding at 220°C.

[0030] Figure 11 Laser confocal micrograph of the composite material of Comparative Example 3 before micro-debonding at 220°C. Detailed Implementation

[0031] 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.

[0032] 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 the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0033] 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 to which this invention pertains. 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.

[0034] Preparation method One aspect of the present invention provides a method for preparing an interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, comprising steps (1)-(3), which are described in detail below.

[0035] Step (1) of the present invention is a step of preparing organic ligands, which includes reacting aromatic rigid scaffolds and hydrogen bond synthons in a high-boiling organic solvent at a microwave power of 300-900 W (e.g., 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900 W) for 5-15 min (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 min) to obtain organic ligands.

[0036] To synthesize suitable organic ligands for assembling hydrogen-bonded organic frameworks, thereby improving the high-temperature damage monitoring sensitivity and interfacial properties of carbon fiber composites, the molar ratio of aromatic rigid scaffolding to hydrogen-bonded synthons can be controlled within a suitable range. In this invention, the molar ratio of the aromatic rigid scaffolding to hydrogen-bonded synthons is 1:(10-20), for example, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, or 1:20. In a preferred embodiment, the molar ratio of the aromatic rigid scaffolding to hydrogen-bonded synthons is 1:10. In another preferred embodiment, the molar ratio of the aromatic rigid scaffolding to hydrogen-bonded synthons is 1:15. In yet another preferred embodiment, the molar ratio of the aromatic rigid scaffolding to hydrogen-bonded synthons is 1:20.

[0037] In this invention, the aromatic rigid scaffolding, hydrogen bond synthons, and high-boiling-point organic solvents are not particularly limited, and examples of the aromatic rigid scaffolding include, but are not limited to, 1, 4, 5, and 8. Examples of the hydrogen-bonded synthons include, but are not limited to, diaminotriazine, 5-aminoisophthalic acid, and 1,3,5-tris(4-aminophenyl)benzene. Examples of the high-boiling-point organic solvents include, but are not limited to, propionic acid, ethylene glycol, and N-methylpyrrolidone. In a preferred embodiment, the aromatic rigid scaffolding is 1,4,5,8... The aromatic rigid scaffold is 1,6,7,8-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride, the hydrogen bond synthon is 5-aminoisophthalic acid, and the high-boiling organic solvent is ethylene glycol. In yet another preferred embodiment, the aromatic rigid scaffold is 3,4,9,10-perylenetetracarboxylic dianhydride, the hydrogen bond synthon is 1,3,5-tris(4-aminophenyl)benzene, and the high-boiling organic solvent is N-methylpyrrolidone.

[0038] Step (2) of this invention is a step of preparing hydrogen-bonded organic framework modified carbon fibers, which includes mixing a first solvent and the organic ligand to obtain a first solution, impregnating unsized carbon fibers with the first solution for 10-30 min (e.g., 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 min), injecting a second solvent in portions, and maintaining the temperature at 50-80℃ (e.g., 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80℃) for 0.5-4 h (e.g., 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4 h) after each injection. Carbon fibers with surface hydrogen-bonded organic frameworks are obtained by evaporation at 80-120℃ (e.g., 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120℃) for 12-72 h (e.g., 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72 h), wherein the second solvent is injected 2-4 times (e.g., 2, 3, 4 times). Among them, the hydrogen-bonded organic framework is formed by the in-situ self-assembly and growth of organic ligands through hydrogen bonding and π-π interactions.

[0039] To improve the sensitivity of high-temperature damage monitoring and enhance the interfacial properties of carbon fiber composites, the volume ratio of the cumulative injected amounts of the first solvent and the second solvent can be controlled within a suitable range. In this invention, the volume ratio of the cumulative injected amounts of the first solvent and the second solvent is 1:(1-4), preferably 1:(2-4), for example 1:2, 1:2.5, 1:3, 1:3.5, or 1:4. In one preferred embodiment, the volume ratio of the cumulative injected amounts of the first solvent and the second solvent is 1:2. In another preferred embodiment, the volume ratio of the cumulative injected amounts of the first solvent and the second solvent is 1:3. In yet another preferred embodiment, the volume ratio of the cumulative injected amounts of the first solvent and the second solvent is 1:4.

[0040] To improve the high-temperature damage monitoring sensitivity and interfacial properties of carbon fiber composites, the mass of the hydrogen-bonded organic framework (HBO) modified layer on the carbon fiber surface can be controlled within a suitable range. In this invention, the mass of the HBO modified layer is 1-2 wt% of the carbon fiber, for example, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, or 2 wt%. In a preferred embodiment, the mass of the HBO modified layer is 1 wt% of the carbon fiber. In another preferred embodiment, the mass of the HBO modified layer is 1.5 wt% of the carbon fiber. In yet another preferred embodiment, the mass of the HBO modified layer is 2 wt% of the carbon fiber.

[0041] In this invention, the carbon fiber, the first solvent, and the second solvent are not particularly limited. Examples of the carbon fiber include, but are not limited to, high-strength intermediate-modulus carbon fiber, high-strength high-modulus carbon fiber, and high-strength high-modulus high-toughness carbon fiber. Examples of the first solvent include, but are not limited to, N,N-dimethylacetamide, N-methylpyrrolidone, and N,N-dimethylformamide. Examples of the second solvent include, but are not limited to, 1,2,4-trichlorobenzene, 1,2-dichlorobenzene, 1,4-dioxane, and xylene. In a preferred embodiment, the carbon fiber is T800H, the first solvent is N,N-dimethylacetamide, and the second solvent is 1,2,4-trichlorobenzene. In another preferred embodiment, the carbon fiber is M40J, the first solvent is N-methylpyrrolidone, and the second solvent is 1,2-dichlorobenzene. In yet another preferred embodiment, the carbon fiber is M40X, the first solvent is N,N-dimethylformamide, and the second solvent is 1,4-dioxane.

[0042] Step (3) of this invention is a step of obtaining an interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, which includes compounding the hydrogen-bonded organic framework modified carbon fiber with a high-temperature resistant resin system and curing it to obtain the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function. The curing method and apparatus are not particularly limited and can be any methods and apparatus known in the art.

[0043] In this invention, the high-temperature resistant resin system includes a high-temperature resistant epoxy resin and a curing agent. The epoxy resin and curing agent are not particularly limited; examples of the epoxy resin include, but are not limited to, glycidyl amine, epoxidized olefin, and alicyclic epoxy resins; the curing agent includes, but is not limited to, aromatic amines, alicyclic polyamines, and acid anhydrides. In a preferred embodiment, the epoxy resin is a glycidyl amine type epoxy resin, and the curing agent is an aromatic amine curing agent. In another preferred embodiment, the epoxy resin is an epoxidized olefin epoxy resin, and the curing agent is an alicyclic polyamine curing agent. In yet another preferred embodiment, the epoxy resin is an alicyclic epoxy resin, and the curing agent is an acid anhydride curing agent.

[0044] It is understood that, in each step of the preparation method of the present invention, those skilled in the art may perform conventional purification operations such as washing, filtering, and drying on the product as needed, which is also within the scope of protection of the present invention.

[0045] This invention has conducted in-depth research to simultaneously improve the high-temperature damage monitoring sensitivity and interfacial properties of carbon fiber composites. The results show that by first impregnating organic ligands with a first solution to pre-adsorb ligand molecules onto the carbon fiber surface, and then injecting a second solvent in stages to gradually increase the volume of the second solvent in the system, it is possible to induce heterogeneous nucleation of hydrogen-bonded organic frameworks on the carbon fiber surface. Subsequently, isothermal evaporation is used to allow the hydrogen-bonded organic frameworks to further grow on the carbon fiber surface to form a crystalline layer, thereby obtaining a carbon fiber composite material with simultaneously improved high-temperature damage monitoring sensitivity and interfacial properties.

[0046] The method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function of the present invention can sometimes be referred to as "a method for simultaneously improving the high-temperature damage monitoring sensitivity and interface properties of carbon fiber composite material".

[0047] In this invention, "high-temperature damage monitoring" refers to the process of identifying, locating, or characterizing damage generated inside or on the surface of carbon fiber composite materials at an ambient temperature of not less than 200°C. The sensitivity of high-temperature damage monitoring refers to the ease and discernibility of detecting damage to carbon fiber composite materials under the aforementioned high-temperature conditions. The sensitivity can be comprehensively judged by factors such as the low-damage nature of the detection method and the significance of the damage signal. For example, the less additional damage the method causes to the material itself, the higher the sensitivity. When using fluorescence detection, the more obvious the changes in fluorescence intensity, color, or distribution pattern between the damaged area and the normal area, the easier it is to observe or identify, thus indicating high monitoring sensitivity.

[0048] carbon fiber composite materials This invention provides an interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, which is obtained by the preparation method described in this invention.

[0049] This invention utilizes organic ligands to self-assemble into a crystalline ordered framework structure through complementary hydrogen bond sites. By leveraging the ability of the hydrogen-bonded organic framework to undergo structural evolution such as hydrogen bond network rearrangement / partial breakage, framework contraction / expansion under external stimuli such as temperature, it achieves simultaneous improvement in high-temperature damage monitoring sensitivity and the interfacial properties of carbon fiber composite materials.

[0050] The carbon fiber composite material of the present invention has a highly sensitive high-temperature damage monitoring function, exhibiting interfacial shear strengths of not less than 95.15 MPa and 56.23 MPa at 25°C and 220°C, respectively, with an interfacial shear strength retention rate of not less than 59.1% at 220°C. The high-temperature damage monitoring function and the detection of interfacial shear strength can be performed using methods and apparatus known in the art, and are not particularly limited thereto.

[0051] application One aspect of the present invention provides the application of the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to the present invention in high-temperature resistant composite materials. Examples of applications of the high-temperature resistant composite material include, but are not limited to, aerospace structural components (e.g., but not limited to wings, rudders, diagonal beams, front and rear beams, etc.), sports equipment (e.g., but not limited to tennis rackets, golf clubs, bicycle frames, etc.), electronic devices (e.g., but not limited to mobile phone casings, shielding covers, antenna structural components, etc.), and transportation vehicle structural components (e.g., but not limited to automobile bodies, train chassis, drive shafts, wheel hubs, interior parts, etc.).

[0052] Example 1 The following illustrates the preparation method and performance testing of interface-reinforced carbon fiber composites with high-temperature damage monitoring function.

[0053] 1. Preparation method (1) 1, 4, 5, 8 Naphthalenetetracarboxylic dianhydride and diaminotriazine were mixed at a molar ratio of 1:10 and reacted in propionic acid solvent at a microwave power of 300 W for 15 min. After washing, filtration and drying, the organic ligand powder was obtained.

[0054] (2) Unsized high-strength intermediate-modulus carbon fibers (T800H) were immersed in an N,N-dimethylacetamide solution containing the above-mentioned organic ligands for 10 min to pre-adsorb the ligand molecules onto the carbon fiber surface. 1,2,4-trichlorobenzene was injected in stages, gradually increasing the volume of 1,2,4-trichlorobenzene in the system. After each injection, the system was maintained at 50°C for 4 h to induce heterogeneous nucleation of the hydrogen-bonded organic framework on the carbon fiber surface. Finally, the system was evaporated at 80°C for 72 h to further grow the hydrogen-bonded organic framework on the carbon fiber surface to form a crystalline layer. The carbon fibers were then dried to obtain hydrogen-bonded organic framework-modified carbon fibers. The number of injection stages was 2, the volume ratio of 1,2,4-trichlorobenzene to the second solvent was 1:2, and the mass fraction of the hydrogen-bonded organic framework-modified layer was 1 wt% of the carbon fiber. (3) The above carbon fiber monofilaments are combined with a glycidylamine type epoxy resin / aromatic amine curing agent system and cured by heating to obtain an interface-reinforced monofilament composite material that can be monitored for high-temperature damage.

[0055] 2. Performance Testing Resin microdroplets with diameters ranging from 40 to 60 μm were selected and subjected to micro-debonding tests at test temperatures of 25℃ and 220℃ respectively, using a microscope. The interfacial shear strengths of the monofilament composites were measured to be 104.56 MPa and 63.22 MPa, respectively, and the interfacial shear strength retention rate at 220℃ was 60.6%.

[0056] The single-filament composite material before and after the high-temperature micro-debonding test at 220℃ was excited at a wavelength of 480 nm under a laser confocal microscope. It was found that the fluorescence disappeared in the damaged area of ​​the composite material after the high-temperature micro-debonding test at 220℃.

[0057] Example 2 The following illustrates the preparation method and performance testing of interface-reinforced carbon fiber composites with high-temperature damage monitoring function.

[0058] 1. Preparation method (1) 1,6,7,8-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride and 5-aminoisophthalic acid were mixed at a molar ratio of 1:15 and reacted in ethylene glycol solvent at a microwave power of 600 W for 10 min. After washing and filtration, the organic ligand powder was obtained by drying.

[0059] (2) Unsized high-strength, high-modulus carbon fibers (M40J) were immersed in an N-methylpyrrolidone solution containing the aforementioned organic ligands for 20 min to pre-adsorb the ligand molecules onto the carbon fiber surface. 1,2-Dichlorobenzene was injected in stages, gradually increasing the volume of 1,2-dichlorobenzene in the system. After each injection, the system was maintained at 60°C for 2 h to induce heterogeneous nucleation of the hydrogen-bonded organic framework on the carbon fiber surface. Finally, the system was evaporated at 100°C for 36 h to further grow the hydrogen-bonded organic framework on the carbon fiber surface, forming a crystalline layer. The carbon fibers were then dried to obtain hydrogen-bonded organic framework-modified carbon fibers. The number of injection stages was three, the volume ratio of N-methylpyrrolidone to 1,2-dichlorobenzene was 1:3, and the mass fraction of the hydrogen-bonded organic framework-modified layer was 1.5 wt% of the carbon fiber. (3) The above carbon fiber monofilaments are combined with an epoxy resin / alicyclic polyamine curing agent system of epoxidized olefins and cured by heating to obtain an interface-reinforced monofilament composite material that can be monitored for high-temperature damage.

[0060] 2. Performance Testing Resin microdroplets with diameters ranging from 40 to 60 μm were selected and subjected to micro-debonding tests at test temperatures of 25℃ and 220℃ respectively, using a microscope. The interfacial shear strengths of the monofilament composites were measured to be 95.15 MPa and 56.23 MPa, respectively, with an interfacial shear strength retention rate of 59.1% at 220℃.

[0061] The single-filament composite material before and after the high-temperature micro-debonding test at 220℃ was excited at a wavelength of 561 nm under a laser confocal microscope. It was found that the fluorescence disappeared in the damaged area of ​​the composite material after the high-temperature micro-debonding test at 220℃.

[0062] Example 3 The following illustrates the preparation method and performance testing of interface-reinforced carbon fiber composites with high-temperature damage monitoring function.

[0063] 1. Preparation method (1) 3,4,9,10-perylenetetracarboxylic dianhydride and 1,3,5-tris(4-aminophenyl)benzene were mixed at a molar ratio of 1:20 and reacted in N-methylpyrrolidone solvent at a microwave power of 900 W for 5 min. After washing and filtration, the organic ligand powder was obtained by drying.

[0064] (2) Unsized high-strength, high-modulus, and high-toughness carbon fibers (M40X) were immersed in an N,N-dimethylformamide solution containing the aforementioned organic ligands for 30 min to pre-adsorb the ligand molecules onto the carbon fiber surface. 1,4-dioxane was injected in stages to gradually increase the volume of 1,4-dioxane in the system. After each injection, the system was maintained at 80°C for 0.5 h to induce heterogeneous nucleation of the hydrogen-bonded organic framework on the carbon fiber surface. Finally, the system was evaporated at 120°C for 12 h to further grow the hydrogen-bonded organic framework on the carbon fiber surface to form a crystalline layer. The carbon fibers were then dried to obtain hydrogen-bonded organic framework-modified carbon fibers. The number of injection stages was four, the volume ratio of N,N-dimethylformamide to 1,4-dioxane was 1:4, and the mass fraction of the hydrogen-bonded organic framework-modified layer was 2 wt% of the carbon fiber. (3) The above carbon fiber monofilaments are combined with an alicyclic epoxy resin / anhydride curing agent system and cured by heating to obtain an interface-reinforced monofilament composite material that can be monitored for high-temperature damage.

[0065] 2. Performance Testing Resin microdroplets with diameters ranging from 40 to 60 μm were selected and subjected to micro-debonding tests at test temperatures of 25℃ and 220℃ respectively, using a microscope. The interfacial shear strengths of the monofilament composites were measured to be 118.77 MPa and 71.21 MPa, respectively, with an interfacial shear strength retention rate of 60.0% at 220℃.

[0066] The single-filament composite material before and after the high-temperature micro-debonding test at 220℃ was excited at a wavelength of 633 nm under a laser confocal microscope. It was found that the fluorescence disappeared in the damaged area of ​​the composite material after the high-temperature micro-debonding test at 220℃.

[0067] Comparative Example 1 The following shows the preparation method and performance testing of carbon fiber composite materials.

[0068] 1. Preparation method Unsized high-strength, high-modulus, high-toughness carbon fiber (M40X) monofilaments were combined with an alicyclic epoxy resin / anhydride curing agent system and cured by heating to obtain unmodified monofilament composite materials.

[0069] 2. Performance Testing At a test temperature of 220℃, resin microdroplets with a diameter range of 40-60 μm were selected by microscopic observation and subjected to micro-debonding test at a loading rate of 0.1 mm / min. The interfacial shear strength of the monofilament composite material was measured to be 62.73 MPa and 26.87 MPa, respectively, and the interfacial shear strength retention rate at 220℃ was 42.8%.

[0070] The single-filament composite material was excited at a wavelength of 633 nm before and after the micro-debonding test at 220℃ using a laser confocal microscope. It was found that the composite material showed no fluorescence before and after the micro-debonding test at 220℃.

[0071] Comparative Example 2 The following shows the preparation method and performance testing of carbon fiber composite materials.

[0072] 1. Preparation method (1) 1,6,7,8-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride and 5-aminoisophthalic acid were mixed at a molar ratio of 1:15 and reacted in ethylene glycol solvent at a microwave power of 600 W for 10 min. After washing and filtration, the organic ligand powder was obtained by drying.

[0073] (2) Unsized high-strength, high-modulus carbon fibers (M40J) were immersed in an N-methylpyrrolidone solution containing the aforementioned organic ligands for 20 min to pre-adsorb the ligand molecules onto the carbon fiber surface; 1,2-dichlorobenzene was injected in a single injection, and the system was maintained at 60°C for 6 h; finally, the system was evaporated at 100°C for 36 h and dried to obtain hydrogen-bonded organic framework modified carbon fibers. The volume ratio of N-methylpyrrolidone to 1,2-dichlorobenzene was 1:3, and the mass fraction of the hydrogen-bonded organic framework modified layer was 1.5 wt% of the carbon fibers. (3) The above carbon fiber monofilaments are combined with an epoxy resin / alicyclic polyamine curing agent system of epoxidized olefins and cured by heating to obtain a monofilament composite material that can be monitored for high temperature damage and has interface reinforcement.

[0074] 2. Performance Testing Resin microdroplets with diameters ranging from 40 to 60 μm were selected and subjected to micro-debonding tests at test temperatures of 25℃ and 220℃ respectively, using a microscope. The interfacial shear strengths of the monofilament composites were measured to be 80.27 MPa and 40.38 MPa, respectively, with an interfacial shear strength retention rate of 50.3% at 220℃.

[0075] Excitation of the single-filament composite material before and after the high-temperature micro-debonding test at 220℃ using a laser confocal microscope at a wavelength of 561 nm could not determine the disappearance of fluorescence in the damaged area of ​​the composite material after the high-temperature micro-debonding test at 220℃.

[0076] Comparative Example 3 The following shows the preparation method and performance testing of carbon fiber composite materials.

[0077] 1. Preparation method (1) A mixture of 3,4,9,10-perylenetetracarboxylic dianhydride, 1,8-octanediamine, and triethylamine was dissolved in N,N-dimethylformamide in a molar ratio of 2:4:1, subjected to ultrasonic treatment, and refluxed at 100°C for 12 hours under a nitrogen atmosphere. After cooling to room temperature, the powder was filtered, washed, and dried to obtain a dark red solid powder.

[0078] (2) The above solid powder was dispersed in chloroform, and methanol was rapidly injected at a volume ratio of 5:1. The mixture was stirred in the solvent for 30 minutes to obtain a perylene imide suspension with a mass concentration of 1.0 wt%. Unsized high-strength, high-modulus carbon fiber (M40J) bundles were immersed in the suspension for 4 hours, during which they were subjected to 2-minute pulsed ultrasonic treatment at 30-minute intervals. Finally, they were dried for 4 hours to obtain perylene imide-modified carbon fibers.

[0079] (3) The above carbon fiber monofilaments are combined with an epoxy resin / alicyclic polyamine curing agent system of epoxidized olefins and cured by heating to obtain a monofilament composite material that can be monitored for high temperature damage and has interface reinforcement.

[0080] 2. Performance Testing Resin microdroplets with diameters ranging from 40 to 60 μm were selected and subjected to micro-debonding tests at test temperatures of 25℃ and 220℃ respectively, using a microscope. The interfacial shear strengths of the monofilament composites were measured to be 91.73 MPa and 50.21 MPa, respectively, with an interfacial shear strength retention rate of 55.0% at 220℃.

[0081] Excitation of the single-filament composite material before and after the high-temperature micro-debonding test at 220℃ using a laser confocal microscope at a wavelength of 561 nm could not determine the disappearance of fluorescence in the damaged area of ​​the composite material after the high-temperature micro-debonding test at 220℃.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, characterized in that, It includes the following steps: (1) React aromatic rigid scaffolds and hydrogen bond synthons in a high-boiling-point organic solvent at a microwave power of 300-900 W for 5-15 min to obtain organic ligands; (2) Mix the first solvent and the organic ligand to obtain a first solution, impregnate the unsized carbon fiber with the first solution for 10-30 min, inject the second solvent in several batches and keep it at 50-80℃ for 0.5-4 h after each injection, and evaporate it at 80-120℃ for 12-72 h to obtain carbon fiber modified with hydrogen bonded organic framework, wherein the second solvent is injected 2-4 times; (3) The hydrogen-bonded organic framework modified carbon fiber is combined with a high-temperature resistant resin system and cured to obtain the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function.

2. The method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 1, characterized in that, In step (1), the molar ratio of the aromatic rigid scaffold and the hydrogen bond synthon is 1:(10-20).

3. The method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 1, characterized in that, In step (1), the aromatic rigid scaffolding includes 1, 4, 5, 8 The hydrogen-bonded synthon comprises at least one of naphthalenetetracarboxylic dianhydride, 1,6,7,8-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, and biphenyltetracarboxylic dianhydride, wherein the hydrogen-bonded synthon comprises at least one of diaminotriazine, 5-aminoisophthalic acid, and 1,3,5-tris(4-aminophenyl)benzene, and the high-boiling organic solvent comprises at least one of propionic acid, ethylene glycol, and N-methylpyrrolidone.

4. The method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 1, characterized in that, In step (2), the volume ratio of the cumulative injected amounts of the first solvent and the second solvent is 1:(1-4).

5. The method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 1, characterized in that, In step (2), the mass of the hydrogen-bonded organic framework modified layer is 1-2 wt% of the carbon fiber.

6. The method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 1, characterized in that, The first solvent includes at least one of N,N-dimethylacetamide, N-methylpyrrolidone, and N,N-dimethylformamide, and the second solvent includes at least one of 1,2,4-trichlorobenzene, 1,2-dichlorobenzene, 1,4-dioxane, and xylene.

7. The method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 1, characterized in that, The carbon fiber includes at least one of high-strength intermediate-modulus carbon fiber, high-strength high-modulus carbon fiber, and high-strength high-modulus high-toughness carbon fiber.

8. The method for preparing the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 1, characterized in that, The high-temperature resistant resin system includes a high-temperature resistant epoxy resin and a curing agent; Preferably, the epoxy resin includes at least one of glycidyl amine, epoxidized olefins and alicyclic epoxy resins, and the curing agent includes at least one of aromatic amines, alicyclic polyamines and acid anhydrides.

9. An interface-reinforced carbon fiber composite material with high-temperature damage monitoring function, characterized in that, It is obtained by the preparation method described in any one of claims 1-8.

10. The application of the interface-reinforced carbon fiber composite material with high-temperature damage monitoring function according to claim 9 in high-temperature resistant composite materials.

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