A reshaping-induced orientation composite material and a preparation method and application thereof

Abstract

The present application belongs to the field of composite materials, and particularly relates to a reshaped and induced oriented composite material and a preparation method and application thereof. The composite material is prepared according to the following steps: synthesizing a thermosetting resin-based composite material with internal fillers uniformly distributed, wherein the resin matrix of the thermosetting resin-based composite material contains dynamic covalent bonds; keeping at 100-250 DEG C for 5-200 min to activate the dynamic covalent bond exchange reaction in the composite material, and then applying an external force or displacement constraint at the temperature to induce the recombination of the dynamic crosslinking network in the composite material, thereby producing a permanent deformation; and the reshaping method realizes the directional arrangement of the filling materials in the composite material, and the reshaped and induced oriented composite material is obtained. The present application realizes the low-cost and convenient operation directional arrangement of the filling materials in the composite material, and is expected to be further applied to the preparation of various anisotropic composite materials.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, specifically relating to a reshaping-induced orientation composite material and its preparation method, which is used to prepare anisotropic composite materials. Background Technology

[0002] Thermosetting resin-based composites primarily use thermosetting resins with covalently cross-linked networks as the matrix and nanomaterials, chopped fibers, and fiber cloths as fillers. They possess excellent specific strength, specific stiffness, fatigue resistance, and corrosion resistance, and are widely used in numerous fields such as machinery manufacturing, transportation, aerospace, and national defense. For example, nanocomposites with added montmorillonite not only exhibit excellent mechanical properties but also good heat resistance and gas barrier properties, and are extensively used in modern automotive components such as engine hood linings, fuel lines, and air intakes.

[0003] Nanomaterials, chopped fibers, and fiber cloths, among other fillers, exhibit excellent mechanical, thermal, and electrical properties when aligned with specific orientations. Compared to traditional composite materials prepared using direct filler dispersion methods, the oriented arrangement of fillers within composite materials creates anisotropy and results in superior mechanical, thermal, and electrical properties. Anisotropic composite materials have applications in numerous fields such as photovoltaics, sensing, energy transmission, and energy storage. For example, electrospun polymer fibers containing oriented nanorods are used in flexible, freestanding surface-enhanced Raman scattering.

[0004] Currently, the following traditional orientation methods can be used to orient the fillers inside composite materials according to the actual engineering application requirements: For fibrous materials such as cellulose, uniaxial stretching can be used to induce fiber alignment. An external force is applied along the direction in which the fibers inside the polymer need to be oriented. The stretching orientation method is simple to operate, but it is difficult to determine the stretching parameters and ensure the fiber orientation effect; Applying an electric field to a polymer solution containing conductive fillers such as metallic fillers or carbon nanotubes will cause the filler material in the solution to align between the two electrodes. This method mainly utilizes the conductive properties of the filler itself; the charged material will move and orient itself according to the direction of the electric field; Injecting a suspension containing magnetic filler materials such as metal oxide sheets onto a substrate near a magnet or magnetic field. In this method, magnetic materials align along the direction of the magnetic field, utilizing their magnetism to orient themselves under the influence of a strong magnetic field. While electric or magnetic fields can relatively quickly orient materials in a polymer solution, these methods require sophisticated equipment and are only suitable for conductive or magnetic fillers. Electrospinning is another option, where the polymer solution is jet-spun under an electric field, causing the material in the solution to align orderly along the fiber generation direction. This method primarily utilizes the electric field to guide the micro-jet of polymer, resulting in the orienting of the material within the jet. Electrospinning can align fillers along the fiber generation direction, but it is difficult to obtain separate long or short fibers. Furthermore, the organic solvents used in some electrospinning systems are expensive and difficult to recycle, easily causing environmental pollution. Therefore, some orientation methods require sophisticated equipment, and other methods, such as electric field induction, are only suitable for conductive materials and difficult to apply to other types of fillers. Currently, methods for orienting fillers are still under research both domestically and internationally, and this remains a challenging problem to be solved. Besides the aforementioned nanocomposites, the fiber orientation in chopped fiber reinforced composites is also crucial to their mechanical properties. For example, chopped carbon fibers possess excellent mechanical strength and good thermal stability, but like one-dimensional nanomaterials, their thermal conductivity is optimal along the axial direction. Traditional methods of inducing carbon fiber alignment by applying an electric field require not only high electric field strength but also complex equipment. Therefore, developing new methods to control the orientation of chopped fibers in composite matrices is a significant challenge.

[0005] In conclusion, it is particularly important to ensure that the filler materials inside composite materials have an orientation that is beneficial to production applications. Summary of the Invention

[0006] To address the problems of traditional orientation methods for composite materials being complex in operation, requiring sophisticated equipment, and unable to alter the orientation of fillers within cured composite materials, this invention provides a method for preparing composite materials with reshaping-induced orientation. This method offers advantages such as simple operation, low cost, and the ability to reorient fillers within cured composite materials. As long as dynamic bonds capable of undergoing dynamic bond exchange reactions exist within the resin matrix of the composite material, such as ester bonds, urea bonds, boron-oxygen bonds, borate ester bonds, amide bonds, imine bonds, thioether bonds, disulfide bonds, or thioester bonds, the filler can be reoriented. The principle is that dynamic bond exchange reactions occurring within the resin matrix lead to network topology reorganization, causing permanent deformation of the material. This reshaping induces the filler to oriented.

[0007] This invention is achieved using the following technical solution:

[0008] This invention provides a method for preparing a reshaped, orientation-induced composite material, comprising the following steps:

[0009] A thermosetting resin-based composite material with uniformly distributed internal fillers is synthesized, wherein the thermosetting resin matrix of the composite material contains dynamic covalent bonds;

[0010] The dynamic covalent bond exchange reaction in the composite material is activated by holding it at 100℃~250℃ for 5min~200min. Then, external force or displacement constraint is applied at this temperature. Permanent deformation is obtained through the reorganization of the dynamic cross-linking network inside the composite material. This reshaping method is used to achieve the directional arrangement of fillers inside the composite material, resulting in a reshaping-induced orientation composite material.

[0011] In a preferred embodiment of the present invention, the dynamic covalent bond is a dynamic covalent bond system of ester bond, urea bond, boron-oxygen bond, borate ester bond, amide bond, imine bond, thioether bond, disulfide bond or thioester bond.

[0012] As a preferred embodiment of the present invention, the method of reshaping by applying external force or displacement constraint is stretching, creeping, stress relaxation or compression reshaping.

[0013] More preferably, the method for reshaping the material is to stretch it, with the strain rate set to 0.01% / min to 0.2% / min and the stretching time to 40min to 200min;

[0014] When reshaping using creep methods, the creep load is 0.1MPa to 3MPa, the creep time is set to 40min to 200min, and the creep recovery time is set to 20min to 60min.

[0015] When reshaping using the stress relaxation method, the strain is set to 0.5% to 2%, and the temperature range is 100℃ to 250℃.

[0016] When reshaping using the compression method, the compression load is set to 1MPa~10MPa, and the experimental temperature is 100℃~250℃.

[0017] The purpose of applying external force is to maintain a low stress level and induce the directional rearrangement of the internal filling material without damaging the specimen structure.

[0018] In a preferred embodiment of the present invention, the filler is a nano-metallic material, a nano-non-metallic material, a natural fiber, an inorganic fiber, or a synthetic fiber.

[0019] More preferably, the filler is selected from gold nanowires, silver nanowires, gold nanorods, iron oxide nanorods, silicon dioxide nanowires, carbon nanotubes, silicon nanocones, carbon nanoribbons, boron nitride, graphene, polyaniline rods, cellulose, lignin, chitin, silk fibers, chopped carbon fibers, chopped glass fibers, boron fibers, ceramic fibers, metal fibers, chopped aramid fibers, or liquid crystal polymer fibers.

[0020] The present invention also provides a composite material prepared according to any of the above methods.

[0021] As a preferred embodiment of the present invention, the thermosetting resin-based composite material containing dynamically covalently bonded internal fillers with uniform distribution is synthesized according to the following steps:

[0022] After the filler material is mixed and dispersed with epoxy resin, a catalyst and polybasic acid or anhydride curing agent such as phthalic anhydride, glutaric anhydride or maleic anhydride are added to carry out a dynamic bond exchange reaction, resulting in a composite material with uniformly dispersed internal filler.

[0023] More preferably, the molar ratio of epoxy groups in the epoxy resin, acyl groups in the curing agent, and catalyst is 1.0-1.5:0.5-1.0:0.05-0.20.

[0024] The present invention also provides the application of the composite material in the manufacture of load-bearing components in the transportation or aerospace fields, wherein the load-bearing components have the ability to withstand loads in a specific direction and provide thermal insulation and air barrier properties.

[0025] In the aerospace field, there are components with specific requirements for axial load-bearing capacity. Orienting composite material components along the axial direction can improve their mechanical properties and make them better suited for structural load-bearing. The composite material with oriented internal filler prepared by this invention has excellent mechanical properties and can be used to manufacture load-bearing components in transportation and aerospace fields such as automotive engine hood liners, air intakes, aircraft panels, and wing skins.

[0026] The present invention has the following beneficial technical effects:

[0027] The method for preparing reshaped and induced-orientation composite materials provided by this invention can be widely applied to the orientation of internal fillers in composite materials. This method is convenient to operate, requires moderate temperature, can reorient the filler material within a cured composite material, and has good reliability. Applying a small external force or displacement constraint at a specific temperature can induce the oriented alignment of the filler material and obtain good material properties. It overcomes the limitations of traditional orientation methods, such as complex operation procedures, high costs, and the inability to change the orientation of the internal filler material in a cured composite material.

[0028] The preparation method provided by this invention has a wide range of applications. Its orientation mechanism involves a dynamic bond exchange reaction occurring within the resin matrix of the composite material, which reorganizes the network topology and induces permanent deformation of the material. This reshaping induces the directional arrangement of the filler material. This orientation method can be applied to the directional arrangement of various nanomaterials or fiber materials. Nanomaterials can be selected from nano-metallic materials or nano-non-metallic materials, and fiber materials can be selected from natural fibers, inorganic fibers, or synthetic fibers. Nano-metallic materials include gold nanowires, silver nanowires, gold nanorods, and iron oxide nanorods; nano-non-metallic materials include silica nanowires, carbon nanotubes, silicon nanocones, carbon nanoribbons, boron nitride, graphene, and polyaniline rods; natural fibers include cellulose, lignin, chitin, and silk fibers; inorganic fibers include chopped carbon fibers, chopped glass fibers, boron fibers, ceramic fibers, and metal fibers; and synthetic fibers include chopped aramid fibers or liquid crystal polymer fibers. Attached Figure Description

[0029] Figure 1 This is a flowchart of the preparation process of the reshaping-induced orientation composite material in this invention.

[0030] Figure 2 This is a schematic diagram of the mechanism of the orientation of the filler material in this invention.

[0031] Figure 3 It is a stretching and reshaping process that induces the directional alignment of the filler material.

[0032] Figure 4 It is a compression-reshaping-induced directional alignment of the filler material.

[0033] Figure 5 It is a compression-reshaping-induced filling material that is oriented along an arbitrary curvature direction.

[0034] Figure 6 This is a graph showing the tensile test results of the composite material before and after the orientation of the internal filler material.

[0035] Figure 7 This is a transmission electron microscope image of an unoriented carbon nanotube reinforced composite material.

[0036] Figure 8This is a transmission electron microscope image of an oriented carbon nanotube reinforced composite material. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] Compared to traditional uniformly dispersed and oriented composite materials, the fillers within composite materials, after being oriented, exhibit anisotropy and achieve superior mechanical, thermal, and electrical properties. Anisotropic composite materials have applications in numerous fields such as photovoltaics, sensing, energy transmission, and energy storage. However, traditional orientation methods are demanding in terms of equipment and cost; some methods, such as electric field induction, are only applicable to conductive fillers and difficult to use with other types of fillers. Besides common nanofillers, the fiber orientation in chopped fiber reinforced composite materials is also crucial to their mechanical properties. For example, chopped carbon fibers possess excellent mechanical strength and good thermal stability, but like one-dimensional nanomaterials, their thermal conductivity is optimal when chopped fibers are aligned axially. Traditional electric field induction for chopped carbon fiber alignment requires not only high electric field strength but also complex equipment. Therefore, developing new methods to control the orientation of chopped fibers in composite matrices is a significant challenge. Thus, achieving a definite orientation of the filler material within composite materials is crucial, necessitating the development of a novel, simple, efficient, and cost-effective filler material orientation method.

[0039] This invention provides a method for preparing a reshaping-induced orientation composite material, which can be widely used in the preparation of anisotropic composite materials. The method includes the following steps:

[0040] A thermosetting resin-based composite material with uniformly distributed internal fillers was synthesized. The resin matrix of the thermosetting resin-based composite material contains dynamic covalent bonds. The composite material was held at 100℃ to 250℃ for 5 min to 200 min to activate the dynamic covalent bond exchange reaction. Then, external force or displacement constraint was applied at this temperature, resulting in permanent deformation through the reorganization of the dynamic cross-linked network within the composite material. This reshaping method achieves the directional arrangement of fillers in the composite material, yielding a reshaped, oriented composite material.

[0041] Figure 1 This is a flowchart of the reshaping-induced orientation arrangement of filler materials in composite materials provided by the present invention. Composite material samples with randomly distributed internal filler materials are synthesized. The filler materials are induced to orient themselves by slow stretching, creep, stress relaxation or hot pressing reshaping at high temperature, and finally the orderly orientation arrangement of filler materials is achieved.

[0042] Figure 2This diagram illustrates the mechanism of filler material orientation in this invention. Within a temperature range of 100℃ to 250℃, the composite material gradually enters a viscous flow state. With the rapid progress of dynamic bond exchange reactions, the dynamic network topology reorganizes, inducing permanent deformation in the material. Under the induction of external force or displacement, the filler material will orient itself along the direction of dynamic network reorganization. When the temperature drops and the external force is removed, the composite material retains the permanent deformation. At this point, a new internal dynamic network structure is formed, and the filler material will maintain its oriented state.

[0043] Furthermore, in this invention, as long as the resin matrix has dynamic covalent bonds, a dynamic bond exchange reaction can occur, thus achieving the directional arrangement of the filler material. The dynamic covalent bonds include dynamic covalent bond systems such as ester bonds, urea bonds, boron-oxygen bonds, borate ester bonds, amide bonds, imine bonds, thioether bonds, disulfide bonds, or thioester bonds.

[0044] The filling material in this invention can be a variety of nanomaterials or fiber materials, such as nano-metallic materials, nano-non-metallic materials, natural fibers, inorganic fibers or synthetic fibers.

[0045] For example, the filler material can be selected from nano-metallic materials such as gold nanowires, silver nanowires, gold nanorods, and iron oxide nanorods; nano-non-metallic materials such as silica nanowires, carbon nanotubes, silicon nanocones, carbon nanoribbons, boron nitride, graphene, and polyaniline rods; natural fibers such as cellulose, lignin, chitin, and silk fibers; inorganic fibers such as chopped carbon fibers, chopped glass fibers, boron fibers, ceramic fibers, and metal fibers; and synthetic fibers such as chopped aramid fibers or liquid crystal polymer fibers.

[0046] The method for orienting filler materials provided by this invention works by activating bond exchange reactions in the dynamic network within the resin matrix at a certain temperature, inducing permanent deformation and remodeling. The filler material then orients itself according to the direction of the dynamic network's reorganization. Therefore, conditions such as temperature, load level, and loading time determine the final orienting effect of the filler material. For example, at lower temperatures such as 100℃ and lower loads such as 0.1MPa, the rate of dynamic bond exchange reactions within the matrix is ​​slow, requiring a longer loading time to achieve a good orienting effect. Similarly, at higher temperatures such as 200℃ and higher loads of 0.5MPa, a significant orienting effect can be achieved in just 40 minutes. The experimental conditions for this orienting method should be varied depending on the material preparation and formulation.

[0047] The filler orientation method in this invention can be widely used in the orientation of fillers in composite materials and the preparation of anisotropic composite materials. It requires moderate temperature, has a simple processing flow, can reorient fillers in cured composite materials, and has good reliability.

[0048] The following description is based on specific embodiments.

[0049] Example 1

[0050] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0051] (1) Preparation of composite materials with uniformly dispersed internal filling materials

[0052] In this embodiment, the filler material is first uniformly dispersed in the polymer solution. Commonly used dispersion methods include physical dispersion and chemical dispersion. Physical dispersion methods include milling, ultrasonication, and mechanical stirring, while chemical dispersion methods include washing with strong acids and alkalis. Dispersants can also be added to assist in achieving uniform dispersion of the filler material. Carbon nanotubes are used as an example of the added filler material, with a diameter of 10–30 nanometers, a length of 10–30 micrometers, and a content of 95 wt%.

[0053] The main components of the resin matrix of the composite material are bisphenol A diglycidyl ether monomer, glutaric anhydride and catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene;

[0054] Carbon nanotubes were added to the bisphenol A diglycidyl ether monomer and stirred at 110°C for 30 min until homogeneous. The mixture was then ultrasonically dispersed in an ice bath for 40 min to ensure uniform dispersion of the carbon nanotubes in the solution. After ultrasonic treatment, the catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene was added to the solution. The mixture containing 1,5,7-triazabicyclo[4.4.0]dec-5-ene was stirred at 110°C for 30 min until the catalyst was completely dissolved. The temperature was lowered to 70°C, and glutaric anhydride was added to the mixture and stirred rapidly. The bisphenol A diglycidyl ether monomer, glutaric anhydride, and catalyst were added in a molar ratio of epoxy functional group: acyl functional group: catalyst of 1:1:0.1. Finally, the air bubbles in the mixed solution were removed in a vacuum drying oven, poured into a pre-treated mold, and placed in an oven for curing. The curing conditions were 100°C for 4 hours, then raised to 130°C and held for another 4 hours to obtain a composite material with uniformly dispersed internal filling material.

[0055] (2) Slow stretching induces the orientation of the filler material

[0056] The composite material obtained in (1) above was stretched using a Zwick tensile testing machine with a large deformation load, and the strain rate of the tensile testing machine was set to 0.1% / min. After holding at 180℃ for 10 min, it was slowly stretched at the same temperature for 40 min, unloaded, and held at the same temperature for 30 min to obtain a reshaped and oriented composite material. The experimental principle is as follows: Figure 3 As shown.

[0057] Under the induction of high temperature and external force, the bond exchange reaction inside the resin matrix of the composite material is activated, the dynamic network topology is changed, and the permanent deformation of the material is achieved. This shaping method causes the filler material to be oriented and arranged with the dynamic network recombination movement.

[0058] Example 2

[0059] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0060] Slow stretching induces the directional alignment of filler materials

[0061] The composite material obtained in Example 1 was subjected to tensile testing using a Zwick tensile testing machine with a large deformation load. The strain rate of the tensile testing machine was set to 0.01% / min. After holding at 100°C for 10 min, the material was slowly stretched for 200 min at the same temperature. After unloading, it was held at the same temperature for 30 min to obtain a reshaped and oriented composite material. The experimental principle is as follows: Figure 3 As shown.

[0062] Example 3

[0063] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0064] Slow stretching induces the directional alignment of filler materials

[0065] The composite material obtained in Example 1 was subjected to tensile testing using a Zwick tensile testing machine with a large deformation load. The strain rate of the tensile testing machine was set to 0.2% / min. After holding at 250°C for 5 min, the material was slowly stretched for 100 min at the same temperature. After unloading, the material was held at the same temperature for 30 min to obtain a reshaped and oriented composite material. The experimental principle is as follows: Figure 3 As shown.

[0066] Example 4

[0067] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0068] Slow stretching induces the directional alignment of filler materials

[0069] The composite material obtained in Example 1 was subjected to tensile treatment using a Zwick tensile testing machine with a large deformation load. The strain rate of the tensile testing machine was set to 0.05% / min. After holding at 180°C for 10 min, the material was slowly stretched for 150 min at the same temperature. After unloading, it was held at the same temperature for 30 min to obtain a reshaped and oriented composite material. The experimental principle is as follows: Figure 3 As shown.

[0070] Example 5

[0071] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0072] Slow stretching induces the directional alignment of filler materials

[0073] Using the composite material obtained in Example 1, a tensile load was applied to the composite material using a force loading mode. The force loading rate could vary from 2 N / min to 15 N / min. In this example, a specific force loading rate of 3 N / min was selected. After holding at 100°C for 10 min, the material was slowly stretched at the same temperature for 100 min, unloaded, and then held at the temperature for 30 min to obtain a reshaped and induced-orientation composite material. The experimental principle is as follows: Figure 3 As shown.

[0074] Example 6

[0075] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0076] Creep-induced directional alignment of filler materials

[0077] Using the composite material obtained in Example 1, force constraints were applied to both ends of the experimental specimen using a Zwick large deformation tensile tester. After holding at 180°C for 10 min, a load of 0.2 MPa was applied, followed by creep for 40 min and a creep recovery time of 30 min. The principle is as follows: Figure 3 As shown.

[0078] Example 7

[0079] A method for preparing a reshaping-induced orientation composite material differs from Example 6 only in that:

[0080] Creep-induced directional alignment of filler materials

[0081] Using the composite material obtained in Example 1, force constraints were applied to both ends of the test specimen using a Zwick large deformation tensile tester. After holding at 140°C for 10 minutes, a load of 0.3 MPa was applied, and creep was carried out for 200 minutes with a creep recovery time of 60 minutes.

[0082] Example 8

[0083] A method for preparing a reshaping-induced orientation composite material differs from Example 6 only in that:

[0084] Creep-induced directional alignment of filler materials

[0085] Using the composite material obtained in Example 1, force constraints were applied to both ends of the test specimen using a Zwick large deformation tensile tester. After holding at 250°C for 5 minutes, a load of 0.1 MPa was applied, with the creep time set to 80 minutes and the creep recovery time set to 20 minutes.

[0086] Examples 6-8 show that as the temperature increases, the dynamic network inside the composite material is gradually activated, and the faster the creep rate, the faster the orientation rate of the internal filler material; furthermore, the irreversible deformation of the composite material also increases. This reshaping method allows the oriented arrangement of the filler material to be preserved. Moreover, at 180°C and a load level of 0.2 MPa, the carbon nanotubes in the sample containing 2 wt% carbon nanotubes can achieve good oriented alignment within 40 minutes. It is important to note that the external force set for creep should not be too large, otherwise it may cause irreversible large deformation or even fracture of the material.

[0087] Example 9

[0088] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0089] Stress relaxation-induced directional alignment of filler materials

[0090] Using the composite material obtained in Example 1, the specimen was held at 200°C for 10 minutes, and then displacement constraints were applied to both ends of the test specimen using a Zwick tensile testing machine with large deformation load. The relaxation test temperature was set at 200°C, and the specimen strain was set at 1%. The experimental principle is as follows: Figure 3 As shown, stress relaxation is used to reshape the specimen, thereby inducing the directional alignment of the filler material.

[0091] Example 10

[0092] A method for preparing a reshaping-induced orientation composite material differs from Example 9 only in that:

[0093] Stress relaxation-induced directional alignment of filler materials

[0094] The composite material obtained in Example 1 was used. The specimen was held at 250°C for 5 minutes, and then displacement constraints were applied to both ends of the test specimen using a Zwick large deformation tensile tester. The relaxation test temperature was set at 250°C, and the specimen strain was set at 0.5%. The experimental principle is as follows: Figure 3 As shown, stress relaxation is used to reshape the specimen, thereby inducing the directional alignment of the filler material.

[0095] Example 11

[0096] A method for preparing a reshaping-induced orientation composite material differs from Example 9 only in that:

[0097] Stress relaxation-induced directional alignment of filler materials

[0098] The composite material obtained in Example 1 was used. The specimen was held at 180°C for 5 minutes, and then displacement constraints were applied to both ends of the test specimen using a Zwick tensile testing machine with large deformation load. The relaxation test temperature was set at 180°C, and the specimen strain was set at 2%. The experimental principle is as follows: Figure 3 As shown, stress relaxation is used to reshape the specimen, thereby inducing the directional alignment of the filler material.

[0099] Experimental results show that as the temperature increases, the relaxation time of the composite materials provided in Examples 9-11 becomes shorter and shorter. This indicates that the dynamic network inside the composite material is activated, the dynamic bond exchange reaction becomes faster, and the network structure is reorganized faster. This reshaping method enables the filler material to be oriented and arranged more quickly along the direction of displacement constraint.

[0100] Example 12

[0101] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0102] Compression deformation induces directional alignment of filler materials

[0103] The composite material from Example 1 was used, held at 180°C for 10 minutes, and then compressed using a Zwick tensile testing machine with a large deformation load at 180°C and an external load of 3 MPa. The experimental principle is as follows: Figure 4 As shown. Compression is used to reshape the sample, thereby inducing the directional alignment of the filler material.

[0104] Example 13

[0105] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0106] Compression deformation induces directional alignment of filler materials

[0107] The composite material from Example 1 was used, held at 100°C for 5 minutes, and then compressed using a Zwick tensile testing machine with a large deformation load at 100°C and an external load of 10 MPa. The experimental principle is as follows: Figure 4 As shown. Compression is used to reshape the sample, thereby inducing the directional alignment of the filler material.

[0108] Example 14

[0109] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0110] Compression deformation induces directional alignment of filler materials

[0111] The composite material from Example 1 was used, held at 250°C for 5 minutes, and then compressed using a Zwick tensile testing machine with a large deformation load at 250°C under an external load of 1 MPa. The experimental principle is as follows: Figure 4 As shown. Compression is used to reshape the sample, thereby inducing the directional alignment of the filler material.

[0112] The experimental results from Examples 12 to 14 show that after compression, the filling material inside the composite material is oriented and arranged perpendicular to the axial compression direction.

[0113] Example 15

[0114] A method for preparing a reshaping-induced orientation composite material includes the following steps:

[0115] Compression-reshaping induced filler materials are oriented along arbitrary curvature directions.

[0116] Using the composite material from Example 1, the flat sample was held at 200°C for 5 minutes, and then hot-pressed for 2 hours at 200°C and 3 MPa using a hot press molding machine and a mold with a certain curvature. The experimental procedure is as follows. Figure 5 As shown, composite materials undergo significant, irreversible deformation after being stretched or compressed at high temperatures. This permanent deformation allows the filler material within the composite material to orient itself, while simultaneously achieving complete reshaping of the composite material's shape, thus producing anisotropic composite materials.

[0117] The experimental results show that composite materials can not only be reshaped into different shapes, such as reshaping a flat sample into a curved sample with a certain curvature, but also the filling material inside the composite material will be oriented along the curvature direction.

[0118] Example 16

[0119] A method for preparing a reshaped orientation-induced composite material differs from Example 1 only in that the filler material is silver nanowires when preparing the composite material with uniformly dispersed internal filler material, and bisphenol A diglycidyl ether monomer, glutaric anhydride and catalyst are added in a molar ratio of epoxy functional group: acyl functional group: catalyst of 1.5:1:0.1.

[0120] Example 17

[0121] A method for preparing a reshaped orientation-induced composite material differs from Example 1 only in that the filler material is cellulose when preparing the composite material with uniformly dispersed internal filler material, and the bisphenol A diglycidyl ether monomer, glutaric anhydride and catalyst are added in a molar ratio of epoxy functional group: acyl functional group: catalyst of 1.5:0.5:0.1.

[0122] Example 18

[0123] A method for preparing a reshaped orientation-induced composite material differs from Example 1 only in that the filler material used in the preparation of the composite material with uniformly dispersed internal filler material is short-cut carbon fiber, and the bisphenol A diglycidyl ether monomer, glutaric anhydride and catalyst are added in a molar ratio of epoxy functional group: acyl functional group: catalyst of 1.0:0.5:0.2.

[0124] Example 19

[0125] A method for preparing a reshaped orientation-induced composite material differs from Example 1 only in that the filler material is graphene when preparing the composite material with uniformly dispersed internal filler material, and bisphenol A diglycidyl ether monomer, glutaric anhydride and catalyst are added in a molar ratio of epoxy functional group: acyl functional group: catalyst of 1.0:0.5:0.2.

[0126] Since all Examples 1 to 19 yielded composite materials with oriented internal filling materials, this invention will only use the composite material with oriented internal filling materials obtained in Example 1 as an example to illustrate the anisotropy of tensile-induced materials and the orientation of internal filling materials from both macroscopic and microscopic perspectives.

[0127] 1. Tensile test

[0128] Tensile tests were performed on the composite material before and after the tensile-induced directional arrangement of the internal filling material in Example 1, using a Zwick large deformation tensile testing machine with a tensile rate set to 3 mm / min. The results are as follows: Figure 6 As shown.

[0129] The results showed that the tensile strength of the composite material with uniformly dispersed internal filler (unoriented) was 42.6 ± 1.9 MPa, and the Young's modulus was 1709.6 ± 15.4 MPa; the tensile strength of the composite material perpendicular to the induction direction (oriented) was 46.7 ± 0.2 MPa, and the Young's modulus was 1866.2 ± 16.8 MPa; the tensile strength of the composite material along the induction direction (oriented) was 51.1 ± 0.8 MPa, and the Young's modulus was 1872.5 ± 21.8 MPa. This indicates that the composite material with oriented internal filler provided by the present invention has significantly improved strength along the tensile direction, and the composite material has better mechanical properties.

[0130] 2. Transmission electron microscopy observation

[0131] Transmission electron microscopy (TEM) was used to observe the composite material with the stretched internal filling material orientation induced in Example 1, as well as the unstretched composite material. The results are as follows: Figures 7-8 As shown. By Figure 7 It can be observed that, at a scale of 200 nm, the filler material inside the composite material appears to be in a scattered state, not yet oriented. From... Figure 8 It can be seen that at a scale of 200 nm, the internal filling material exhibits obvious directional arrangement characteristics.

[0132] The above embodiments are merely preferred examples of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A method of preparing a reshaped shape inducing oriented composite material, characterized in that, The method comprises the following steps: The thermosetting resin-based composite material with uniformly distributed internal fillers is synthesized, and the resin matrix in the thermosetting resin-based composite material contains dynamic covalent bonds; The dynamic covalent bond exchange reaction in the composite material is activated by maintaining at 100-250 DEG C for 5-200 min, and an external force or displacement constraint is applied at the temperature to induce the reorganization of the dynamic crosslinking network inside the composite material, so that permanent deformation is obtained, the internal filler of the composite material is oriented and arranged by using the reshaping method, and a reshaped and induced oriented composite material is obtained; The reshaping method by applying an external force or displacement constraint is tensile, creep, stress relaxation or compression reshaping; When the tensile method is used for reshaping, the strain rate is set to 0.01% / min-0.2% / min, and the tensile time is 40-200 min; When the creep method is used for reshaping, the creep load is 0.1-3 MPa, the creep time is set to 40-200 min, and the creep recovery time is set to 20-60 min; When the stress relaxation method is used for reshaping, the strain is set to 0.5%-2%, and the experimental temperature is 100-250 DEG C; When the compression method is used for reshaping, the compression load is set to 1-10 MPa, and the experimental temperature is 100-250 DEG C.

2. The method of claim 1, wherein the method further comprises the step of: The dynamic covalent bond is a dynamic covalent bond system of an ester bond, a urea bond, a boron-oxygen bond, a borate ester bond, an amide bond, an imine bond, a sulfide bond, a disulfide bond or a thioester bond.

3. The method of claim 1, wherein the method further comprises the step of: The filler is selected from the group consisting of gold nanowires, silver nanowires, gold nanorods, ferroferric oxide nanorods, silica nanowires, carbon nanotubes, graphene, polyaniline rods, cellulose, lignin, chitin, silk fibers, chopped carbon fibers, chopped glass fibers, boron fibers, ceramic fibers, metal fibers, chopped aramid fiber or liquid crystal polymer fiber.

4. A composite material prepared by the method according to any one of the above 1-3.

5. Use of the composite material according to claim 4 for the manufacture of load-bearing parts in the field of transport or load-bearing parts in the field of aerospace, characterized in that, The load-bearing component has the performance of bearing specific directional load and heat insulation and air resistance.

6. Use according to claim 5, characterized in that, The composite material is used for manufacturing an engine cover liner, an air inlet hole, an aircraft wall plate or a wing skin of an automobile. The load-bearing component has the performance of bearing specific directional load and heat insulation and air resistance.

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