A multi-scale network structure intercalated resin matrix composite material, a preparation method thereof and application thereof

Abstract

The present application relates to a kind of multi-scale network structure intercalation resin matrix composite material and its preparation method and application, on the fiber surface of the non-woven fabric or fabric skeleton that three-dimensional interweaving of micron fiber, construct the three-dimensional network thin layer of nano carbon, obtain multi-scale network structure intercalation;It is placed between fiber cloth layer, obtain fiber preform;Again, resin slurry is perfused, solidification forming, obtain multi-scale network structure intercalation resin matrix composite material.The present application process is simple, easy to implement;Multi-scale network structure intercalation is introduced, the three-dimensional network thin layer of nano carbon on the surface of micron fiber and resin form the interface structure that the bonding strength decreases from surface to interior gradient, further play the synergistic enhancement of nano carbon material and micron fiber to interlayer toughness and damping performance;The obtained multi-scale network structure intercalation resin matrix composite material, while having excellent interlayer toughness and damping performance, especially suitable as structural damping composite material use while keeping good mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of resin-based composite materials and their preparation methods, specifically relating to a multi-scale network structure intercalated resin-based composite material, its preparation method, and its application. Background Technology

[0002] Compared to metallic materials, fiber-reinforced resin matrix composites, prepared through a series of processes using resin as the matrix and continuous fibers as the reinforcement, possess significant advantages such as high specific strength and high specific stiffness, leading to their widespread application in aerospace, transportation, construction, and sporting goods. Vibration and noise issues can significantly reduce the stability and reliability of equipment operation, shortening its service life. In high-speed applications such as spacecraft, marine propellers, and high-speed trains, the vibration reduction and noise reduction performance of composite materials is particularly important.

[0003] Improving the damping performance of composite materials can effectively enhance the vibration reduction and noise reduction capabilities of structures across the entire frequency range. Currently, strategies for improving the damping performance of fiber-reinforced resin matrix composites mainly include resin matrix modification, fiber fabric surface modification, and interlayer intercalation. The mechanisms primarily rely on the movement of matrix molecular chains and interfacial friction and slip between components. In recent years, nanomaterials with excellent mechanical properties and damping characteristics, such as carbon nanotubes, graphene, and graphene oxide, have been widely used for the damping modification of carbon fiber / epoxy resin composites. Uniformly dispersing nanomaterials in the resin matrix can improve damping performance through interfacial friction between nanomaterials and resin; however, this strategy has limited effectiveness and faces problems such as poor nanomaterial dispersion and decreased processability due to increased resin viscosity.

[0004] In contrast, macroscopic bodies with a three-dimensional network structure formed by interwoven carbon nanotubes, such as carbon nanotube films or foams, can effectively dissipate energy under stress through the slippage between carbon nanotubes, with a loss factor exceeding 0.3. When combined with fiber-reinforced resin-based composites, the damping performance of the composite material can be significantly improved by utilizing the interfacial friction between the carbon nanotubes and the resin, as well as the slippage mechanism of the carbon nanotubes themselves. For example, Li Tianshu et al. pretreated a 2 µm thick carbon nanotube ultrafilm with a m-chloroperoxybenzoic acid / dichloromethane solution, then impregnated the film with resin using a hot-melt method, and alternately layered it with carbon fiber prepreg. A carbon nanotube-intercalated carbon fiber / epoxy resin composite was prepared using a vacuum bag-autoclave molding process, resulting in a two-order-of-magnitude improvement in damping ratio (Li Tianshu, Li Min, Gu Yizhuo, et al. Mechanical enhancement effect of the interlayer hybrid CNTfilm / carbon fiber / epoxy composite [J]. Composites Science and Technology, 2018, 166: 176-182.).

[0005] However, the presence of numerous nanoscale micropores in carbon nanotube films or foams results in poor resin permeability, which would severely degrade the mechanical properties of the composite material if directly laminated. To address this, patent CN 108045039 A proposes preparing through-pores along the thickness direction in carbon nanotube foam intercalations, alternating these pores with resin-impregnated carbon fiber layers, followed by repeated rolling to enhance resin permeability into the intercalated structure. This process produces a structurally damping carbon fiber composite material with both excellent mechanical and damping properties.

[0006] In summary, the preparation of structurally damping carbon fiber composites using three-dimensional network carbon nanotube macrostructures still faces two challenges: first, the preparation of ultrathin carbon nanotube macrostructures is difficult; second, additional process measures are needed to ensure that the resin fully impregnates the carbon nanotube macrostructures, thus increasing the complexity of the process. Summary of the Invention

[0007] Current technologies for preparing structural damping carbon fiber composites using three-dimensional network structured nano-carbon macrostructures suffer from drawbacks such as high difficulty or complex processes in preparing the nano-carbon macrostructures. This invention aims to provide a simple method for preparing structural damping composites using a three-dimensional network structure of nano-carbon, namely, a multi-scale network structure intercalated resin-based composite material and its preparation method. Inexpensive and readily available polar microfiber nonwoven fabric or textile with a three-dimensional interwoven network structure is introduced as a skeleton. First, utilizing the polar and hydrogen bonding interactions between the skeleton fibers and nano-carbon, as well as among the nano-carbon itself, a nano-carbon dispersion modified with functional groups such as hydroxyl, carboxyl, and amine groups is uniformly sprayed onto the surface of the skeleton fibers. This conveniently constructs a thin layer of a three-dimensional interwoven network structure of nano-carbon on the fiber surface, thus eliminating the complex process of directly preparing the three-dimensional network structured nano-carbon macrostructure. Second, the microporous structure rich in the nonwoven fabric or textile effectively promotes resin penetration, achieving good wetting of the nano-carbon three-dimensional network layer on the fiber surface by the resin without additional processing measures. Finally, by utilizing the viscoelasticity of the microfibers themselves and the frictional slippage at the fiber-resin interface, the synergistic reinforcement effect of the microfibers and nano-carbon is fully utilized, thereby significantly improving the damping performance and interlaminar toughness of the resin-based composite material.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A multi-scale network structure intercalated resin-based composite material is obtained by injection and curing of fiber preform and resin slurry; the fiber preform includes fiber cloth and multi-scale network structure intercalation laid between the fiber cloth; the multi-scale network structure intercalation has the following structure: a three-dimensional network thin layer composed of nano-carbon is coated on the surface of a nonwoven fabric or fabric skeleton formed by three-dimensional interweaving of micron fibers.

[0009] Preferably, the nonwoven fabric or woven material is composed of polymer fibers containing polar groups, and the thickness of the nonwoven fabric or woven material is 10–80 µm and the areal density is 8–20 g / m². 2 The diameter of the microfiber is 10–50 µm; The thickness of the nano-carbon three-dimensional network thin layer is 0.5–1.6 µm; The nano-carbon is carbon nanotube or a mixture of carbon nanotube and graphene oxide. The surface of the carbon nanotube is modified with one or two functional groups, namely hydroxyl, carboxyl, and amino groups. The graphene oxide has a sheet diameter of 1 to 10 µm and a sheet number of 1 to 5 layers.

[0010] Preferably, the fiber cloth is one or more of carbon fiber cloth, glass fiber cloth, aramid fiber cloth, glass fiber / carbon fiber blended cloth, and aramid fiber / carbon fiber blended cloth.

[0011] More preferably, the mass ratio of carbon nanotubes to graphene oxide in the mixture of carbon nanotubes and graphene oxide is 1:1 to 5:1.

[0012] More preferably, the polymer fiber containing polar groups is nylon fiber, polyurethane fiber, aramid fiber, hydrophilic modified polyethylene-polypropylene core-sheath composite fiber or a mixture thereof; The nonwoven fabric is a nonwoven fabric prepared by spunbonding.

[0013] This invention also provides a method for preparing the multi-scale network structure intercalated resin-based composite material as described above, comprising the following steps: Step (1) A stable and dispersed nano-carbon dispersion is uniformly sprayed onto both sides of a non-woven fabric or woven fabric. After drying to remove the solvent, the multi-scale network structure intercalation is obtained. Step (2) The multi-scale network structure obtained in step (1) is intercalated between fiber fabric layers and stacked to obtain a fiber preform; Step (3) Mix the resin and curing agent evenly, and then perform vacuum degassing to obtain resin slurry; Step (4) Place the fiber preform prepared in step (2) into a mold or vacuum bag, and inject it with the resin slurry prepared in step (3). After curing and molding, the multi-scale network structure intercalated resin-based composite material is obtained.

[0014] Preferably, the concentration of the nano-carbon dispersion is 0.1–5 mg / mL; The solvent is selected from one or more of water, ethanol, and acetone.

[0015] Preferably, the molding method is vacuum-assisted resin infusion, vacuum-assisted resin transfer molding, resin transfer molding, hand lay-up molding, autoclave molding, or wet molding.

[0016] Preferably, the resin is a vinyl ester resin, an epoxy resin, or an unsaturated resin.

[0017] The multi-scale network structure intercalated resin matrix composite material described above maintains good mechanical properties while also possessing excellent interlayer toughness and damping properties, making it particularly suitable for structural damping composite materials.

[0018] The technical solution employed in this invention utilizes polar or hydrogen bonding interactions to construct a three-dimensional nano-carbon network thin-layer structure on the fiber surface of a nonwoven fabric or woven skeleton composed of three-dimensionally interwoven polymer microfibers containing polar groups with good viscoelasticity, thus obtaining a multi-scale network structure intercalation. After this intercalation is combined with a resin-based composite material, an interface structure with a gradient decreasing bonding strength from the surface to the interior is formed between the three-dimensional network nano-carbon thin layer on the surface of the microfibers and the resin matrix in the constructed multi-scale network structure intercalation region. This greatly promotes the interaction between the viscoelastic microfibers, resin, and nano-carbon, significantly improving the interlaminar toughness and damping performance of the composite material. The resulting multi-scale network structure intercalated resin-based composite material exhibits a more than 120% improvement in interlaminar fracture toughness compared to the unintercalated reference sample, and a more than 50% improvement in the average loss factor in the 1-200Hz range compared to the unintercalated reference sample.

[0019] Compared with the prior art, the technical solution of this invention has the following advantages: 1. The present invention provides a method for preparing a multi-scale network structure intercalated resin-based composite material, which uses inexpensive and readily available raw materials, has a simple process, and is easy to implement; 2. The present invention provides a method for preparing a multi-scale network structure intercalated resin matrix composite material. The multi-scale network structure intercalation introduces a bonding strength gradient decreasing from the surface to the interior between the nano-carbon three-dimensional network thin layer on the surface of the microfiber and the resin matrix, thereby realizing the synergistic enhancement of interlayer toughness and damping performance by nano-carbon materials and microfibers. 3. The multi-scale network structure intercalated resin-based composite material provided by the present invention significantly improves interlayer toughness and damping performance while maintaining good mechanical properties, and is particularly suitable for use as a structural damping composite material. Attached Figure Description

[0020] Figure 1 The nylon nonwoven fabric (area density of 16 g / m²) used in Comparative Example 2 and Example 1 2 Scanning electron microscope images at different magnifications.

[0021] Figure 2 The images are scanning electron microscope (SEM) images of the CNT-nylon nonwoven multiscale network structure intercalation 1 prepared in Example 1 at different magnifications.

[0022] Figure 3 Scanning electron microscope image of the type I interlaminar toughness section of the multi-scale network structure intercalation composite material 1 prepared in Example 1. Detailed Implementation

[0023] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0024] The testing standards / methods used in the embodiments of this invention are as follows: The microstructure of the nonwoven fabric or woven material and the multi-scale network structure intercalation was observed using field emission scanning electron microscopy. The diameters of 20 fibers in the obtained scanning electron micrographs of the nonwoven fabric or woven material and the multi-scale network structure intercalation were measured using software, and the average fiber diameter was calculated. The average thickness of the nano-carbon three-dimensional network thin layer in the multi-scale network structure intercalation was obtained from the difference between the average radius of the fibers in the multi-scale network structure intercalation and the average radius of the fibers in the nonwoven fabric or woven material skeleton.

[0025] According to the double cantilever beam method of ASTM-D5528, the type I interlaminar fracture toughness of the composite material was tested using an electromechanical universal testing machine. The sample size was 150 mm × 25 mm × 4 mm, and the loading rate was 2 mm / min. The microstructure of the obtained composite material cross-section was observed using field emission scanning electron microscopy.

[0026] According to ASTM-D7905, the type II interlaminar fracture toughness of the composite material was tested using a three-point bending test with end notches. The sample size was 150 mm × 25 mm × 4 mm. The loading rate was 1 mm / min.

[0027] The flexural properties of the composite material were tested according to ASTM-D 7264 standard. The sample size was 155 mm × 13 mm × 4 mm. The loading rate was 1 mm / min, and the span-to-thickness ratio was 32:1.

[0028] The damping properties of the composite material were tested using a dynamic mechanical analyzer (DMAQ850, TA Instruments, USA). The test mode was a double cantilever beam with sample dimensions of 60 mm × 10 mm × 2 mm and a beam span of 35 mm. The strain was maintained at 0.01%, and frequency scanning was performed at 25°C, with a frequency range of 1–200 Hz. The average loss factor obtained at all different frequencies was calculated to obtain the average loss factor from 1 to 200 Hz, which was used to evaluate the damping performance of the composite material.

[0029] The layup structures of various test samples used in the embodiments of this invention are as follows: Layup structure of intercalated composite material samples used for interlaminar toughness testing: The fiber cloth layup is [0]. 20Intercalation layers are laid only between the 10th and 11th fiber cloth layers, and polytetrafluoroethylene films are placed at the ends to form pre-cracks.

[0030] The layup structure of the intercalated composite material sample used for damping performance testing: the fiber cloth layup method is [(±45°)3 / 45°], and intercalation layers are laid between all fiber cloth layers.

[0031] The layup structure of the intercalated composite material sample used for bending performance testing: the fiber cloth layup method is [0]. 20 Intercalation layers are laid between all the fiber fabric layers.

[0032] The layup structure of non-intercalated composite material samples used for various performance tests is the same as that of intercalated composite material samples, but there are no intercalations between the fiber cloth layers.

[0033] Comparative Example 1: Preparation of intercalated carbon fiber / vinyl ester resin composite material A vacuum-assisted resin casting molding process was employed. Vinyl ester resin (MFE 30, Huachang Polymer Co., Ltd., East China University of Science and Technology) and curing agent (M-50) were mixed at a ratio of 100:2 (mass ratio) and stirred until homogeneous. The mixture was then placed in a 25℃ vacuum oven for degassing for 10 min to obtain a resin slurry. The slurry had an areal density of 200 g / m³. 2 T700 carbon fiber unidirectional fabric was used to lay fiber preforms for various test samples on a glass plate coated with a release agent. These preforms were then placed in a sealed vacuum bag and resin slurry was injected under a vacuum of 25°C and -0.1 MPa. After injection, the samples were cured sequentially at 55°C for 4 hours, 80°C for 2 hours, and 100°C for 2 hours at a heating rate of 2°C / min to obtain the composite material samples required for testing (denoted as the non-intercalated composite material). The samples were cut into strips of the required dimensions using a CNC laser cutter and subjected to various tests. The type II interlaminar toughness was measured to be 1.416 kJ / m. 2 The average loss factor for 1-200 Hz is 0.01380, and the bending strength and bending modulus are 788 MPa and 96.1 GPa, respectively.

[0034] Comparative Example 2: Preparation of Nylon Nonwoven Fabric Intercalated with Carbon Fiber / Vinyl Ester Resin Composite Material A vacuum-assisted resin casting molding process was employed. Vinyl ester resin (MFE 30, Huachang Polymer Co., Ltd., East China University of Science and Technology) and curing agent (M-50) were mixed and stirred evenly at a ratio of 100:2 (mass ratio). The mixture was then vacuum degassed in a vacuum oven for 10 minutes to obtain a resin slurry. The slurry had an areal density of 200 g / m³. 2 The T700 carbon fiber unidirectional fabric has an areal density of 16 g / m². 2A 75 µm thick nylon nonwoven fabric was used as the basis for various test samples. Fiber preforms were laid on a glass plate coated with a release agent. The preforms were placed in a sealed vacuum bag and resin slurry was injected under vacuum conditions of 25°C and -0.1 MPa. After injection, the preforms were cured sequentially at 55°C for 4 h, 80°C for 2 h, and 100°C for 2 h at a heating rate of 2°C / min to obtain the composite material sample required for testing (denoted as nylon nonwoven intercalation composite material 1). The sample was cut into strips of the required size using a CNC laser cutter, and various tests were performed. The resulting type II interlaminar toughness was 2.639 kJ / m. 2 The average loss factor for 1-200Hz is 0.01820, and the bending strength and bending modulus are 698 MPa and 90.4 GPa, respectively.

[0035] Example 1: Preparation of CNT-Nylon Nonwoven Multiscale Network Structure Intercalated Carbon Fiber / Vinyl Ester Resin Composite Material Commercially available CNT water-based slurry with a concentration of 10 wt% and a surface density of 16 g / m³ was used. 2 Nylon nonwoven fabric with a thickness of 75 µm was used as raw material. The CNT aqueous slurry was diluted with deionized water to 5 mg / mL, stirred evenly, and then treated with an ultrasonic cell disruptor (BRANSON Sonifer 450) at 200 W power for 10 min to obtain a stable CNT aqueous dispersion.

[0036] A 270*370 mm nylon nonwoven fabric was placed in a clean tray. Using an HD-130 airbrush with a nozzle diameter of 0.2 mm, 18 g of CNT aqueous dispersion was evenly sprayed onto the nylon nonwoven fabric at an air pressure of 0.04 MPa and with the nozzle held approximately 50 cm away from the tray. The fabric was then placed in a 75°C forced-air oven to dry for 20 min. After drying, the nylon nonwoven fabric was turned over, and another 18 g of CNT aqueous dispersion was evenly sprayed onto it. The fabric was then placed in a 75°C forced-air oven to dry thoroughly, resulting in a CNT-nylon nonwoven fabric multi-scale network structure intercalation layer 1 with an average thickness of 1.05 µm for the CNT three-dimensional network thin layer.

[0037] Vinyl ester resin (MFE 30, Huachang Polymer Co., Ltd., East China University of Science and Technology) and curing agent (M-50) were mixed at a ratio of 100:2 (by mass) and stirred until homogeneous. The mixture was then placed in a vacuum oven at 25°C for 10 minutes to remove air bubbles, yielding a resin slurry. The slurry had a surface density of 200 g / m³. 2A multi-scale network structure intercalation-1 of T700 carbon fiber unidirectional fabric and CNT-nylon nonwoven fabric was prepared. Various fiber preforms for testing samples were laid on a glass plate coated with a release agent. A vacuum-assisted infusion molding process was used, placing the fiber preforms in a sealed vacuum bag and infusing resin slurry under a vacuum of 25℃ and -0.1 MPa. After infusion, the samples were cured sequentially at 55℃ for 4 h, 80℃ for 2 h, and 100℃ for 2 h at a heating rate of 2℃ / min to obtain the composite material samples required for testing (denoted as multi-scale network structure intercalation composite material 1). The samples were cut into strips of the required size using a CNC laser cutter and subjected to various tests. The type II interlaminar toughness was measured to be 3.119 kJ / m. 2 The average loss factor for 1-200Hz is 0.02078, and the bending strength and bending modulus are 709 MPa and 94.0 GPa, respectively.

[0038] Figure 1 The images show scanning electron microscope (SEM) images of the nylon nonwoven fabrics used in Comparative Example 1 and Example 1, revealing an areal density of 16 g / m². 2 The nylon fibers in a 75 µm thick nylon nonwoven fabric have a relatively smooth surface. The fiber diameter ranges from 24.4 to 33.2 µm, with an average diameter of 27.7 µm. Figure 2 This is a scanning electron microscope (SEM) image of the CNT-nylon nonwoven multi-scale network structure intercalation layer 1 prepared by spraying with CNT aqueous dispersion in Example 1. It can be seen that the nylon fiber surface becomes rough, and at high magnification, a three-dimensional network layer formed by CNT interweaving can be observed, with a very dense surface network structure. The fiber diameter ranges from 24.5 to 33.3 µm, with an average diameter of 29.8 µm. The average thickness of the CNT three-dimensional network thin layer in the CNT-nylon nonwoven multi-scale network structure intercalation layer 1 is calculated to be 1.05 µm.

[0039] Figure 3The image shows a scanning electron microscope (SEM) image of the cross-section of the multi-scale network structure intercalated composite material 1 prepared in Example 1 after a type I interlaminar toughness test. It can be seen that the fibers in the intercalated region experienced peeling or pull-out failure with the resin matrix. Because the CNT three-dimensional network thin layer on the nylon fiber surface forms an interface structure with decreasing bonding strength from the surface inwards, it results in a groove-like peeling fracture morphology: the dense CNT three-dimensional network surface layer, after sufficient resin penetration, forms a surface layer with low resin content and high CNT content, exhibiting strong interfacial bonding, and the applied load can be effectively transferred to the CNTs, leading to ductile pull-out failure of the CNTs; the loose CNT three-dimensional network intermediate layer, after sufficient resin penetration, forms an intermediate layer with high resin content and low CNT content, with reduced interfacial bonding strength, leading to brittle fracture failure; the loose CNT three-dimensional network bottom layer, due to poor resin penetration, forms a weak bonding interface region containing microporous defects, leading to overall brittle peeling failure.

[0040] Comparing the performance data of the multi-scale network structure intercalated composite material 1 prepared in Example 1, the non-intercalated composite material prepared in Comparative Example 1, and the nylon nonwoven fabric intercalated composite material 1 prepared in Comparative Example 2, it can be seen that the type II interlaminar toughness and the average loss factor of 1-200 Hz of the multi-scale network structure intercalated composite material 1 are improved by 120% and 50.6% respectively compared with the non-intercalated composite material; and by 18.2% and 14.2% respectively compared with the nylon nonwoven fabric intercalated composite material 1. The flexural strength and flexural modulus of the multi-scale network structure intercalated composite material 1 are improved by 1.58% and 3.98% respectively compared with the nylon nonwoven fabric intercalated composite material 1. This indicates that constructing a CNT three-dimensional network thin layer with an average thickness of 1.05 µm on the surface of the nylon nonwoven fabric skeleton can not only significantly improve the type II interlaminar toughness and damping performance of the composite material, but also slightly improve its flexural strength and flexural modulus.

[0041] Example 2: Preparation of CNT-Nylon Nonwoven Multiscale Network Intercalated Carbon Fiber / Vinyl Ester Resin Composite Material Commercially available CNT water-based slurry with a concentration of 10 wt% and a surface density of 16 g / m³ was used. 2 Nylon nonwoven fabric with a thickness of 75 µm was used as raw material. The CNT aqueous slurry was diluted with deionized water to 2 mg / mL, stirred evenly, and then treated with an ultrasonic cell disruptor (BRANSON Sonifer 450) at 200 W power for 10 min to obtain a stable CNT aqueous dispersion.

[0042] A 270*370 mm nylon nonwoven fabric was placed in a clean tray. Using an HD-130 airbrush with a 0.2 mm nozzle, 18 g of CNT aqueous dispersion was evenly sprayed onto the nylon nonwoven fabric at an air pressure of 0.04 MPa, with the nozzle held approximately 50 cm away from the tray. The fabric was then dried in a 75°C forced-air oven for 20 minutes. The nylon nonwoven fabric was then flipped over, and the same 18 g of CNT aqueous dispersion was sprayed evenly onto it. The fabric was then dried in a 75°C forced-air oven for another 20 minutes. This process was repeated until all 144 g of CNT aqueous dispersion was evenly sprayed onto the nylon nonwoven fabric. Finally, the fabric was thoroughly dried in an oven to obtain a CNT-nylon nonwoven fabric multi-scale network structure intercalation layer 2, with an average CNT three-dimensional network thin layer thickness of 1.75 µm.

[0043] Vinyl ester resin (MFE 30, Huachang Polymer Co., Ltd., East China University of Science and Technology) and curing agent (M-50) were mixed at a ratio of 100:2 (mass ratio) and stirred until homogeneous. The mixture was then placed in a vacuum oven at 25℃ for 10 min to remove air bubbles, yielding a resin slurry. A surface density of 200 g / m³ was used. 2 T700 carbon fiber unidirectional fabric and CNT-nylon nonwoven fabric multi-scale network structure intercalation 2 were used. Fiber preforms for various test samples were laid on a glass plate coated with a release agent. A vacuum-assisted infusion molding process was employed, placing the fiber preforms in a sealed vacuum bag and infusing resin slurry under a vacuum of 25℃ and -0.1 MPa. After infusion, the samples were cured sequentially at 55℃ for 4 h, 80℃ for 2 h, and 100℃ for 2 h at a heating rate of 2℃ / min to obtain the composite material samples required for testing (denoted as multi-scale network structure intercalated composite material 2). The samples were cut into strips of the required size using a CNC laser cutter and subjected to various tests. The type II interlaminar toughness was measured to be 2.542 kJ / m. 2 The average loss factor for 1-200Hz is 0.01803, and the flexural strength and modulus are 707 MPa and 97.4 GPa, respectively.

[0044] Comparing the performance data of the multi-scale network structure intercalated composite material 2 prepared in Example 2 and the nylon nonwoven fabric intercalated composite material 1 prepared in Comparative Example 2, it can be seen that the type II interlaminar toughness and the average loss factor of 1-200 Hz of the multi-scale network structure intercalated composite material 2, compared with the nylon nonwoven fabric intercalated composite material 1, not only did not improve, but also decreased slightly, by 3.68% and 0.93%, respectively. This is because the thickness of the CNT three-dimensional network thin layer constructed on the surface of the nylon nonwoven fabric skeleton is too large, resulting in the resin not being able to completely penetrate the CNT three-dimensional network thin layer during injection molding. Due to the lack of resin, the interfacial bonding of the intermediate core layer is weak. Under the action of external load, the fiber undergoes overall brittle peeling failure at this weak interface with the matrix, thus failing to exert the self-slipping effect of CNT and its interfacial friction with the resin.

[0045] Comparative Example 3: Preparation of Nylon Nonwoven Fabric Intercalated with Carbon Fiber / Vinyl Ester Resin Composite Material A vacuum-assisted resin casting molding process was employed. Vinyl ester resin (Huachang, MFE-30) and M-30 curing agent were mixed at a ratio of 100:2 (mass ratio) and stirred until homogeneous. The mixture was then placed in a 25℃ vacuum oven for degassing for 10 minutes to obtain a resin slurry. The slurry had an areal density of 200 g / m³. 2 The T700 carbon fiber unidirectional fabric has an areal density of 12 g / m². 2 Nylon nonwoven fabric with a thickness of 50 µm and a fiber diameter of 31.1-41.4 µm was used. Various prefabricated fiber samples for different tests were laid on a glass plate coated with a release agent. The prefabricated fiber was placed in a sealed vacuum bag and resin slurry was poured in under vacuum conditions of 25°C and -0.1 MPa. After pouring, the temperature was increased at a rate of 2°C / min, and then successively cured at 55°C for 4 h, 80°C for 2 h, and 100°C for 2 h to obtain the composite material samples required for testing (denoted as Nylon Nonwoven Intercalated Composite Material 2). The samples were cut into strips of the required size using a CNC laser cutter and subjected to various tests. The type II interlaminar toughness was measured to be 2.730 kJ / m. 2 The average loss factor for 1-200 Hz is 0.01894, and the bending strength and bending modulus are 716 MPa and 86.1 GPa, respectively.

[0046] Example 3: Preparation of CNT-Nylon Nonwoven Multiscale Network Intercalated Carbon Fiber / Vinyl Ester Resin Composite Material Commercially available CNT water-based slurry with a concentration of 10 wt% and a surface density of 12 g / m³ was used. 2Nylon nonwoven fabric with a thickness of 50 µm and a fiber diameter of 31.1-41.4 µm was used as raw material. The aqueous CNT slurry was diluted with ethanol to 3 mg / mL, stirred evenly, and then treated with an ultrasonic cell disruptor (BRANSON Sonifer 450) at 200 W power for 10 min to obtain a stable CNT dispersion.

[0047] A 270*370 mm nylon nonwoven fabric was placed in a clean tray. Using an HD-130 airbrush with a 0.2 mm nozzle and at a pressure of 0.04 MPa, with the nozzle held approximately 50 cm away from the tray, 18 mL of CNT dispersion was evenly sprayed onto the nylon nonwoven fabric. The fabric was then placed in a 30°C vacuum oven to dry for 20 min, and then removed. The nylon nonwoven fabric was then flipped over, and another 18 mL of CNT dispersion was evenly sprayed onto it. After thorough drying in a 30°C vacuum oven, a CNT-nylon nonwoven fabric multi-scale network structure intercalation layer 3 was obtained, with an average thickness of 0.85 µm for the CNT three-dimensional network thin layer.

[0048] Vinyl ester resin (MFE 30, Huachang Polymer Co., Ltd., East China University of Science and Technology) and curing agent (M-50) were mixed at a ratio of 100:2 (mass ratio) and stirred until homogeneous. The mixture was then placed in a vacuum oven at 25℃ for 10 min to remove air bubbles, yielding a resin slurry. A surface density of 200 g / m³ was used. 2 A multi-scale network structure intercalation of T700 carbon fiber unidirectional fabric and CNT-nylon nonwoven fabric was used. Fiber preforms for various test samples were laid on a glass plate coated with a release agent. A vacuum-assisted infusion molding process was employed, placing the fiber preforms in a sealed vacuum bag and infusing resin slurry under a vacuum of 25℃ and -0.1 MPa. After infusion, the samples were cured sequentially at 55℃ for 4 h, 80℃ for 2 h, and 100℃ for 2 h at a heating rate of 2℃ / min to obtain the composite material samples required for testing (denoted as multi-scale network structure intercalated composite material 3). The samples were cut into strips of the required size using a CNC laser cutter and subjected to various tests. The type II interlaminar toughness was measured to be 3.242 kJ / m. 2 The average loss factor for 1-200Hz is 0.0220, and the flexural strength and modulus are 733 MPa and 94.1 GPa, respectively.

[0049] Comparing the performance data of the multi-scale network structure intercalated composite material 3 prepared in Example 3, the non-intercalated composite material prepared in Comparative Example 1, and the nylon nonwoven fabric intercalated composite material 2 prepared in Comparative Example 3, it can be seen that the type II interlaminar toughness and the average loss factor of 1-200 Hz of the multi-scale network structure intercalated composite material 3 are improved by 129% and 59.4% respectively compared with the non-intercalated composite material; and by 18.8% and 16.2% respectively compared with the nylon nonwoven fabric intercalated composite material 2. The flexural strength and flexural modulus of the multi-scale network structure intercalated composite material 3 are improved by 2.37% and 9.29% respectively compared with the nylon nonwoven fabric intercalated composite material 2.

[0050] Example 4: Preparation of CNT / graphene oxide (GO)-nylon nonwoven multiscale network intercalated carbon fiber / vinyl ester resin composite material The following were used: a commercially available 10 wt% CNT aqueous slurry, a 2 mg / mL GO (1 flake number, 3-5 µm flake diameter) aqueous dispersion, and a surface density of 12 g / m³. 2 Nylon nonwoven fabric with a thickness of 50 µm and a fiber diameter of 31.1-41.4 µm was used as raw material. CNT aqueous slurry, GO aqueous dispersion and deionized water were prepared into an aqueous dispersion with a concentration of 0.74 mg / mL at a ratio of 0.1:1.1:15.3 (volume ratio). After stirring evenly, the dispersion was treated with an ultrasonic cell disruptor (BRANSON Sonifer 450) at 200 W power for 10 min to obtain a stable CNT / GO dispersion.

[0051] A 270*370 mm nylon nonwoven fabric was placed in a clean tray. Using an HD-130 airbrush with a 0.2 mm nozzle and at an air pressure of 0.04 MPa, with the nozzle held approximately 50 cm away from the tray, 18 g of CNT / GO aqueous dispersion was evenly sprayed onto the nylon nonwoven fabric. The fabric was then placed in a 75°C forced-air oven for 20 min and removed. The nylon nonwoven fabric was then flipped over, and another 18 g of CNT / GO aqueous dispersion was evenly sprayed onto it. This process was repeated until all 144 g of CNT / GO aqueous dispersion was evenly sprayed onto the nylon nonwoven fabric. Finally, the fabric was thoroughly dried in an oven to obtain a CNT / GO-nylon nonwoven fabric multi-scale network structure intercalation, with an average thickness of 0.94 µm for the CNT / GO three-dimensional network thin layer.

[0052] Vinyl ester resin (MFE 30, Huachang Polymer Co., Ltd., East China University of Science and Technology) and curing agent (M-50) were mixed at a ratio of 100:2 (mass ratio) and stirred until homogeneous. The mixture was then placed in a vacuum oven at 75℃ for 10 min to remove air bubbles, yielding a resin slurry. A surface density of 200 g / m³ was used. 2 A multi-scale network structure intercalation of T700 carbon fiber unidirectional fabric and CNT / GO-nylon nonwoven fabric was performed. Fiber preforms for various test samples were laid on a glass plate coated with a release agent. A vacuum-assisted infusion molding process was used, placing the fiber preforms in a sealed vacuum bag and infusing resin slurry under a vacuum of 25℃ and -0.1 MPa. After infusion, the samples were cured sequentially at 55℃ for 4 h, 80℃ for 2 h, and 100℃ for 2 h at a heating rate of 2℃ / min to obtain the composite material samples required for testing (denoted as multi-scale network structure intercalated composite material 4). The samples were cut into strips of the required size using a CNC laser cutter and subjected to various tests. The type II interlaminar toughness was measured to be 3.423 kJ / m. 2 The average loss factor for 1-200Hz is 0.02313, and the bending strength and bending modulus are 745 MPa and 98.3 GPa, respectively.

[0053] Comparing the performance data of the multi-scale network structure intercalated composite material 4 prepared in Example 4, the non-intercalated composite material prepared in Comparative Example 1, and the nylon nonwoven fabric intercalated composite material 2 prepared in Comparative Example 3, it can be seen that the type II interlaminar toughness and the average loss factor of 1-200 Hz of the multi-scale network structure intercalated composite material 4 are improved by 142% and 67.6% respectively compared with the non-intercalated composite material; and by 25.4% and 22.1% respectively compared with the nylon nonwoven fabric intercalated composite material 2. The flexural strength and flexural modulus of the multi-scale network structure intercalated composite material 4 are improved by 4.05% and 14.2% respectively compared with the nylon nonwoven fabric intercalated composite material 2.

[0054] Although this disclosure has been described above through specific embodiments, it should be understood that those skilled in the art can devise various modifications, improvements, or equivalents to this disclosure within the spirit and scope of the appended solutions. Such modifications, improvements, or equivalents should also be considered to be included within the scope of protection claimed in this disclosure.

Claims

1. A multi-scale network structure intercalated resin-based composite material, characterized in that, The composite material is obtained by injection and curing of fiber preform and resin slurry; the fiber preform includes fiber cloth and multi-scale network structure intercalation layer laid between the fiber cloth; the multi-scale network structure intercalation layer has the following structure: a three-dimensional network thin layer composed of nano-carbon is coated on the fiber surface of the nonwoven fabric or fabric skeleton formed by three-dimensional interweaving of micron fibers.

2. The multi-scale network structure intercalated resin-based composite material according to claim 1, characterized in that, The nonwoven fabric or woven material is composed of polymer fibers containing polar groups, and the thickness of the nonwoven fabric or woven material is 10–80 µm and the areal density is 8–20 g / m². 2 The diameter of the microfiber is 10–50 µm, and the thickness of the three-dimensional carbon nanofiber network is 0.5–1.6 µm. The carbon nanofiber is carbon nanotube or a mixture of carbon nanotube and graphene oxide, and the surface of the carbon nanotube is modified with one or two functional groups of hydroxyl, carboxyl, and amine groups.

3. The multi-scale network structure intercalated resin-based composite material according to claim 1 or 2, characterized in that, The polymer fiber containing polar groups is nylon fiber, polyurethane fiber, aramid fiber, hydrophilically modified polyethylene-polypropylene core-sheath composite fiber or a mixture thereof; the nonwoven fabric is a nonwoven fabric prepared by spunbond method.

4. The multi-scale network structure intercalated resin-based composite material according to claim 1, characterized in that, The fiber cloth is one or more of the following: carbon fiber cloth, glass fiber cloth, aramid fiber cloth, glass fiber / carbon fiber blended cloth, and aramid fiber / carbon fiber blended cloth.

5. A multi-scale network structure intercalated resin-based composite material according to claim 1 or 2, characterized in that, The mass ratio of carbon nanotubes to graphene oxide in the mixture is 1:1 to 5:1; the diameter of the graphene oxide sheets is 1 to 10 µm, and the number of sheets is 1 to 5.

6. A method for preparing the multi-scale network structure intercalated resin-based composite material according to claim 1, characterized in that, The preparation method includes the following steps: Step (1) A stable and dispersed nano-carbon dispersion is uniformly sprayed onto both sides of a non-woven fabric or woven fabric. After drying to remove the solvent, the multi-scale network structure intercalation is obtained. Step (2) The multi-scale network structure obtained in step (1) is intercalated between fiber fabric layers and stacked to obtain a fiber preform; Step (3) Mix the resin and curing agent evenly, and then perform vacuum degassing to obtain resin slurry; Step (4) Place the fiber preform prepared in step (2) into a mold or vacuum bag, and inject it with the resin slurry prepared in step (3). After curing and molding, the multi-scale network structure intercalated resin-based composite material is obtained.

7. The method for preparing a multi-scale network structure intercalated resin-based composite material according to claim 6, characterized in that, The concentration of the nano-carbon dispersion is 0.1–5 mg / mL; the solvent is selected from one or more of water, ethanol, and acetone.

8. The method for preparing a multi-scale network structure intercalated resin-based composite material according to claim 6, characterized in that, The molding method is vacuum-assisted resin infusion, vacuum-assisted resin transfer molding, resin transfer molding, hand lay-up molding, autoclave molding, or wet molding.

9. The method for preparing a multi-scale network structure intercalated resin-based composite material according to claim 6, characterized in that, The resin is a vinyl ester resin, an epoxy resin, or an unsaturated resin.

10. Application of a multi-scale network structure intercalated resin-based composite material as a structural damping composite material.

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