Self-healing fiber-reinforced composite materials based on 3D-printed vascular networks and preparation methods thereof

Abstract

This application relates to a self-healing fiber-reinforced composite material based on a 3D-printed vascular network and a preparation method thereof. The preparation method includes: providing a shell material and a core material; designing a vascular arrangement network and inputting the vascular arrangement network into the program of a 3D printing device; placing the shell material and the core material in a cartridge and inputting them into a microfluidic chip, and using 3D printing to print vascular tubes containing a repair agent on a prepreg layer to obtain a laid prepreg layer; performing autoclave molding on the laid prepreg layer to obtain a self-healing fiber-reinforced composite material. The preparation method of the self-healing fiber-reinforced composite material based on the 3D-printed vascular network provided by this application can achieve arbitrary arrangement of vascular tubes, and the obtained self-healing fiber-reinforced composite material has an integrally formed structure. When the fiber-reinforced composite material is damaged, it increases the coverage range after the repair agent oozes out and generates a repair reaction faster and more stably, thereby improving the repair effect.

Description

Technical Field

[0001] This application relates to the technical field of functional materials, and particularly relates to a self-healing fiber-reinforced composite material based on a 3D-printed vascular network and a preparation method thereof. Background Art

[0002] A self-healing fiber-reinforced composite material containing vasculature is a composite material that establishes an autonomous, stimulus-triggered self-healing system inside the composite material. It is generally prepared by the pre-buried wire removal method and the landfill vasculature method. When the composite material is damaged, the repair liquid in the flow channel will seep into the damaged area and react to achieve the repair effect. However, currently, this technology is cumbersome to operate, the arrangement of the vasculature is greatly affected by human factors, and the stability and repeatability of the repair effect are poor; moreover, the arrangement method of the vasculature has limitations and usually can only achieve a horizontal and vertical layout, which limits the seepage coverage range of the repair liquid after the vasculature is impacted or damaged, and reduces the repair effect. Summary of the Invention

[0003] This application provides a self-healing fiber-reinforced composite material based on a 3D-printed vascular network and a preparation method thereof, which can achieve arbitrary arrangement of the vasculature. When the fiber-reinforced composite material is damaged, it increases the coverage range after the repair agent seeps out, generates a repair reaction faster and more stably, and thus improves the repair effect.

[0004] In a first aspect, this application provides a preparation method of a self-healing fiber-reinforced composite material based on a 3D-printed vascular network, including: providing a shell material and a core material; designing a vascular arrangement network and inputting the vascular arrangement network into the program of a 3D printing device; placing the shell material and the core material in a cartridge, inputting them into a microfluidic chip, and using 3D printing to print vasculature containing a repair agent on a prepreg layer to obtain a laid prepreg layer; performing autoclave molding on the laid prepreg layer to obtain a self-healing fiber-reinforced composite material.

[0005] In some embodiments, the microfluidic chip includes an input channel, a first extrusion channel, and a second extrusion channel.

[0006] In some embodiments, the inner diameter of the input channel is 0.5 mm - 3 mm.

[0007] In some embodiments, the inner diameter of the first extrusion channel is 0.2 mm - 2.5 mm.

[0008] In some embodiments, the inner diameter of the second extrusion channel is 0.4 mm - 3 mm.

[0009] In some embodiments, a micro mixer is provided inside the input channel.

[0010] In some embodiments, the cross-sectional shapes of the input flow channel, the first extrusion flow channel, and the second extrusion flow channel are independently selected from a square, a circle, a triangle, and an ellipse.

[0011] In some embodiments, the steps of printing a vasculature containing a repair agent in a prepreg layer by 3D printing include: setting the position of the vasculature in the prepreg layer according to the total thickness of the prepreg layer; printing one layer of vasculature every 4 - 8 prepreg layers.

[0012] In some embodiments, the extrusion rate of the shell layer material is 1.88 - 5887.5 μL / min.

[0013] In some embodiments, the extrusion rate of the core layer material is 56.56 - 2590.5 μL / min.

[0014] In some embodiments, the formula for the extrusion rate q is:

[0015] ,

[0016] The unit of q is mL / min; ø is the inner diameter of the first extrusion flow channel or the second extrusion flow channel, with the unit of mm, υ x is the moving rate of the first extrusion flow channel or the second extrusion flow channel in the x-axis direction 、υ y is the moving rate of the first extrusion flow channel or the second extrusion flow channel in the y-axis direction, with the unit of mm / s.

[0017] In some embodiments, the moving rate in the x-axis direction is 1 - 20 mm / s, and the moving rate in the y-axis direction is 1 - 20 mm / s.

[0018] In a second aspect, the present application provides a self-healing fiber-reinforced composite material based on a 3D printed vasculature network. The interior of the self-healing fiber-reinforced composite material has a 3D printed vasculature network; the vasculature includes a shell layer material and a core layer material located inside the shell layer material, and the core layer material includes a repair agent.

[0019] In some embodiments, the shell layer material includes a photocurable resin.

[0020] In some embodiments, the repair agent includes a polymer; the polymer includes one or more of a one-component or two-component epoxy resin, a bismaleimide resin, a phenolic resin, and an unsaturated polyester resin.

[0021] In some embodiments, the outer diameter of the vasculature is 0.4 mm - 3 mm.

[0022] In some embodiments, the inner diameter of the vasculature is 0.2 mm - 2.5 mm.

[0023] In the embodiments of the present application, by combining a microfluidic chip with 3D printing technology, arbitrary arrangement of vascular networks can be achieved, and the obtained self-healing fiber-reinforced composite material has an integrally formed structure. When the fiber-reinforced composite material is damaged, the reaction opportunity of the repair agent can be increased, and the repair effect can be improved. At the same time, on the premise of minimizing the internal influence on the fiber-reinforced composite material as much as possible, the application requirements for the long-term service of the fiber-reinforced composite material are strengthened, the structural reliability of the fiber-reinforced composite material is improved, and the service life is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0025] Figure 1 It is a layout diagram of the vascular network on the surface of the fiber-reinforced composite material provided by an embodiment of the present application;

[0026] Figure 2 It is a schematic structural diagram of the microfluidic chip provided by some embodiments of the present application;

[0027] Figure 3 It is a schematic flow diagram of the preparation method of the self-healing fiber-reinforced material provided by some embodiments of the present application.

[0028] Among them, 10, input channel; 11, first input channel; 12, second input channel; 21, first extrusion channel; 22, second extrusion channel; 101, input part; 201, extrusion part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Hereinafter, embodiments of the present application will be described with reference to the drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application.

[0030] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the art belonging to the technical field of the present application; the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion.

[0031] Reference to "embodiment" in this application means that the specific features, structures, or characteristics described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in this application can be combined with other embodiments.

[0032] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0033] In the description of the embodiments of this application, the term "plurality" refers to two or more (including two).

[0034] In the description of the embodiments of this application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific situations.

[0035] Fiber-reinforced composites are widely used in many fields, such as the aerospace and transportation industries, due to their advantages such as light weight and high strength. During the use of fiber-reinforced composites, some damages will inevitably occur, especially damages that are not visible to the naked eye, which are difficult to be detected in time. However, the damaged area will significantly reduce the overall mechanical properties of the fiber-reinforced composites and limit their applications.

[0036] In order to improve the service life of fiber-reinforced composites, researchers have obtained self-healing fiber-reinforced composites containing vasculature by embedding a vasculature network inside the fiber-reinforced composites to achieve automatic repair after damage.

[0037] The preparation methods of conventional composites for self-healing using hollow vasculature generally fall into two categories: one is the pre-embedded wire removal method, that is, pre-embedded wires are placed during the molding process of the prepreg. After molding, the pre-embedded wires are drawn out with external force, and then the repair liquid is poured in for sealing. This method is difficult to operate. Drawing out the pre-embedded wires will seriously affect the interlaminar bonding force of the prepreg and is not easy to operate. The other is to bury hollow vasculature containing the repair liquid. First, the repair liquid is stored in the hollow vasculature by capillary action, and then the hollow vasculature containing the repair liquid is laid into the prepreg. The operation is cumbersome, and it is difficult to control the amount of the repair liquid.

[0038] In addition, in the related art, setting hollow fiber glass tubes in fiber-reinforced composites may affect the strength of the fiber-reinforced composites, and it is difficult to lay layers and difficult to replicate.

[0039] In view of this, the present application provides a self-healing fiber-reinforced composite material based on a 3D-printed vascular network and a preparation method thereof, which can achieve arbitrary arrangement of the vasculature, and when the fiber-reinforced composite material is damaged, it increases the coverage range after the repair agent oozes out, and generates a repair reaction faster and more stably, thereby improving the repair effect.

[0040] The present application provides a self-healing fiber-reinforced composite material based on a 3D-printed vascular network, as Figure 1 shown, the interior of the self-healing fiber-reinforced composite material has a 3D-printed vascular network;

[0041] The vasculature includes a shell material and a core material located inside the shell material, and the core material includes a repair agent.

[0042] It can be understood that the vasculature in the embodiments of the present application has a hollow structure, and the repair agent is filled inside the hollow structure.

[0043] In the embodiments of the present application, a vascular network is obtained inside the self-healing fiber-reinforced material through 3D printing technology, and arbitrary arrangement of the vasculature can be achieved. The vasculature includes a shell material and a core material located inside the shell material, and the core material includes a repair agent. The vasculature serves as an induction path and can sense damages such as interlaminar delamination and matrix microcracks caused by impact on the fiber-reinforced composite material. Since connectivity is established between the vasculature and the damaged area, the repair agent is triggered to transfer to the damaged area to achieve self-healing of the fiber-reinforced composite material. When the fiber-reinforced composite material is damaged, it increases the coverage range after the repair agent oozes out, and generates a repair reaction faster and more stably, thereby improving the repair effect.

[0044] In some embodiments, the vascular network can be a one-dimensional structure or a two-dimensional structure.

[0045] Generally, the landfill shape of the vasculature is horizontal and vertical, which limits the diffusion range of the repair agent after the fiber-reinforced composite material is damaged and further affects the reaction of the repair agent. By using 3D printing technology to print the vasculature containing the repair agent, the path of the vasculature can be made more flexible, that is, a vascular network with a criss-cross arrangement can be realized at the one-dimensional and two-dimensional levels, which promotes the oozing of the repair agent from the vasculature after being damaged and speeds up the repair reaction.

[0046] In some embodiments, the fiber-reinforced composite material is arranged in layers, and the vasculature is located between the layers of the fiber-reinforced composite material. Exemplarily, when the fiber-reinforced composite material has two layers, the vasculature is located between the adjacent layers of the fiber-reinforced composite material. When the fiber-reinforced composite material has more than three layers, the vasculature can be located between any two layers of the fiber-reinforced composite material, that is, in this case, there may be a situation where the vasculature is not provided between two adjacent layers of the fiber-reinforced composite material.

[0047] In the embodiments of the present application, the vasculature is printed by 3D printing technology, which can broaden the selection range of the shell material and the core material.

[0048] In some embodiments, the shell material may include a photocurable resin.

[0049] The photocurable resin has good compatibility with the fiber-reinforced composite material, thereby enhancing the interfacial bonding strength of the fiber-reinforced composite material.

[0050] In some embodiments, the photocurable resin may include one or more of acrylate-based photocurable resins, epoxy-based photocurable resins, polyester acrylate-based photocurable resins, silicone-based photocurable resins, and acrylic-based photocurable resins. By using the photocurable resin, the shell material can be cured by ultraviolet light, and the preparation process is more convenient.

[0051] In some embodiments, the shell material may further include additives, such as functional materials like ceramic powder and metal powder.

[0052] In some embodiments, the repair agent can be a one-component repair agent or a two-component repair agent.

[0053] In some embodiments, the repair agent may include a polymer.

[0054] In some embodiments, the polymer may include one or more of one-component or two-component epoxy resins, bismaleimide resins, phenolic resins, and unsaturated polyester resins.

[0055] By selecting the above polymers, when the composite material is damaged, the polymers can react quickly and have good adhesion with the prepreg, achieving the best repair reaction.

[0056] In some embodiments, the fiber material in the fiber-reinforced composite material may include one or more of glass fiber, carbon fiber, alumina fiber, and silicon carbide fiber.

[0057] In some embodiments, the outer diameter of the vasculature can be 0.4 mm - 3 mm, for example, it can be 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, or a range composed of any two of the above values.

[0058] In some embodiments, the inner diameter of the vasculature can be 0.2 mm - 2.5 mm, for example, it can be 0.2 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.1 mm, 2.3 mm, 2.5 mm, or a range composed of any two of the above values.

[0059] By setting the dimensions of the inner diameter and outer diameter of the vasculature within the above ranges, the mass ratio of the shell material and the core material can be adjusted within a suitable range, which can not only achieve a relatively thin shell thickness, so that when the composite material is subjected to impact damage, the repair agent in the vasculature can seep into the interior of the composite material, but also enable sufficient repair agent to be filled in the vasculature, thereby achieving the best repair effect.

[0060] The present application provides a method for preparing a self-healing fiber-reinforced composite material based on a 3D-printed vasculature network. Figure 3 For the process schematic diagram of the method for preparing the self-healing fiber-reinforced material provided in some embodiments of the present application, as Figure 3 shown, the preparation method includes the following steps:

[0061] S10: Provide a shell material and a core material;

[0062] S20: Design a vasculature layout network and input the vasculature layout network into the program of a 3D printing device;

[0063] S30: Place the shell material and the core material in a cartridge, input them into a microfluidic chip, and use 3D printing to print vasculature containing a repair agent on a prepreg layer to obtain a laid prepreg layer;

[0064] S40: Perform autoclave molding on the laid prepreg layer to obtain a self-healing fiber-reinforced composite material.

[0065] In the embodiments of the present application, by combining a microfluidic chip with 3D printing technology, arbitrary arrangement of vascular networks can be achieved, and the obtained self-healing fiber-reinforced composite material has an integrally formed structure. When the fiber-reinforced composite material is damaged, the reaction opportunity of the repair agent can be increased, and the repair effect can be improved. At the same time, on the premise of minimizing the internal influence on the fiber-reinforced composite material as much as possible, the application requirements for the long-term service of the fiber-reinforced composite material are strengthened, the reliability of the structure of the fiber-reinforced composite material is improved, and the service life is extended.

[0066] In some embodiments, the step of disposing the vasculature inside the prepreg layer may include: printing the vasculature on the surface of the prepreg layer and then laying another prepreg layer on its surface.

[0067] It can be understood that the vasculature in the prepreg layer is a tiled structure, and the fiber material is also a tiled structure, thereby reducing the damage to the fibers during the process of disposing the vasculature.

[0068] In the embodiments of the present application, by combining 3D printing and microfluidic technology, a vascular network containing a repair fluid can be integrally formed, that is, the vascular closure can be achieved by printing only the shell material at the head and tail ends of the vasculature, thereby reducing processes such as filling the hollow vasculature by capillary action and separately sealing the vasculature, and the preparation process is simple and convenient.

[0069] In the embodiments of the present application, by combining 3D printing and microfluidic technology, a vascular network with a core-shell structure can be integrally printed and formed, and the amount of the repair fluid in the vasculature can be precisely controlled.

[0070] In some embodiments, the microfluidic chip can also be prepared by 3D printing technology.

[0071] Before preparing the microfluidic chip, the exposure parameters of the 3D printing equipment need to be tested and adjusted to ensure that the structure of the prepared microfluidic chip does not collapse, clog holes, etc.

[0072] In some embodiments, the material of the microfluidic chip can be a polymer material, for example, it can be polydimethylsiloxane.

[0073] In addition, the microfluidic chip can also be manufactured by standard microelectromechanical system (MEMS) processes or soft lithography techniques, so that the flow channels in the microfluidic chip are precisely defined on the micron to millimeter scale.

[0074] Figure 2 The structural schematic diagram of the microfluidic chip provided by some embodiments of the present application is as Figure 2 shown.

[0075] In some embodiments, the microfluidic chip may include an input channel 10, a first extrusion channel 21, and a second extrusion channel 22. The first extrusion channel 21 is used to extrude the core layer material, and the second extrusion channel 22 is used to extrude the shell layer material.

[0076] By using the channel design inside the microfluidic chip, the regulation of the shell layer material and the core layer material can be achieved, and a vascular tube with a core-shell structure can be printed and formed.

[0077] In some embodiments, a first extrusion channel outlet communicating with the first extrusion channel, a second extrusion channel outlet communicating with the second extrusion channel, and an input channel inlet communicating with the input channel are formed on the surface of the microfluidic chip.

[0078] In some embodiments, the microfluidic chip includes an input part 101 and an extrusion part 201. The first extrusion channel 21 and the second extrusion channel 22 are located in the extrusion part 201, and the input channel 10 is located in the input part 101.

[0079] In some embodiments, the input channel 10 includes a first input channel 11 and a second input channel 12. The first input channel 11 is used to input the core layer material, and the second input channel 12 is used to input the shell layer material.

[0080] The shell layer material and the core layer material are respectively stored in a shell layer material cartridge and a core layer material cartridge. The outlet of the shell layer material cartridge is connected to the second input channel of the microfluidic chip, and the cartridge outlet of the core layer material cartridge is connected to the first input channel.

[0081] The input channel of the microfluidic chip is connected to the connector of the cartridge of the respective 3D printing device. The connection methods include but are not limited to glue bonding and clamp-rubber gasket sealing connection.

[0082] In some embodiments, the extrusion needle of the microfluidic chip is integrally provided with the body of the microfluidic chip. The extrusion needle is the first extrusion channel and the second extrusion channel of the microfluidic chip. Thus, the replacement of the printing needle during the 3D printing process can be reduced, the free replacement of the single-component or two-component core layer material can be realized, and a vascular tube with a core-shell structure can be formed in one step.

[0083] The structure and size of the microfluidic chip can be designed according to actual needs.

[0084] In some embodiments, the inner diameter of the input channel 10 can be 0.5 mm - 3 mm, for example, it can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or the range composed of any two of the above values.

[0085] In some embodiments, the inner diameter of the first extrusion channel 21 can be 0.2 mm - 2.5 mm, for example, it can be 0.2 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.1 mm, 2.3 mm, 2.5 mm, or a range composed of any two of the above values.

[0086] In some embodiments, the inner diameter of the second extrusion channel 22 can be 0.4 mm - 3 mm, for example, it can be 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, or a range composed of any two of the above values.

[0087] When the inner diameters of the first extrusion channel and the second extrusion channel are within the above ranges, the size of the obtained blood vessel can be matched with the thickness of the prepreg layer, further enhancing the strength of the fiber-reinforced composite material.

[0088] In some embodiments, the input channel includes a first input channel 11 and a second input channel 12.

[0089] In some embodiments, the number of the first input channels 11 can be one or more.

[0090] When there are multiple first input channels, during the 3D printing process, by switching between multiple cartridges of the 3D printer and the input channels, without replacing the cartridge or the print head, the free replacement of single-component and double-component core layer materials can be achieved, and the core-shell structure of multiple core layer materials can be formed in one step. When the repair agent in the blood vessel is single-component, only the first input channel can be used without using the second input channel. When the repair agent in the blood vessel is double-component, both the first input channel and the second input channel can be used simultaneously. The embodiments of the present application combine 3D printing and microfluidic technology, with more flexible operation, and can realize the integrated preparation of self-healing composite materials with single-component or double-component repair agents and shell materials.

[0091] In some embodiments, a micro-mixer can be arranged inside the input channel 10.

[0092] The micro-mixer can realize the mixing of core layer materials or shell materials with shear-thinning properties, and can also realize the mixing of high-viscosity polymer materials.

[0093] Exemplarily, the micro-mixer can be a spiral mixing member arranged inside the channel along the axial direction of the channel.

[0094] In some embodiments, the cross-sectional shapes of the input flow channel 10, the first extrusion flow channel 21, and the second extrusion flow channel 22 can be independently selected from a square, a circle, a triangle, and an ellipse.

[0095] In some embodiments, the steps of printing the vasculature containing the repair agent on the prepreg layer using 3D printing may include: setting the position of the vasculature in the prepreg layer according to the total thickness of the prepreg layer; printing one layer of vasculature every 4 - 8 prepreg layers.

[0096] In some embodiments, the extrusion rate of the shell layer material can be 1.88 - 5887.5 μL / min.

[0097] In some embodiments, the extrusion rate of the core layer material can be 56.56 - 2590.5 μL / min.

[0098] By setting the extrusion rates of the core layer material and the shell layer material within the above ranges in the embodiments of the present application, the thickness of the shell layer material and the filling amount of the core layer material in the vasculature can be further adjusted within a suitable range, ensuring that the subsequent formed composite material achieves the best repair effect.

[0099] The extrusion rate is affected by the inner diameter of the flow channel and the moving rate.

[0100] In some embodiments, the formula for the extrusion rate q is:

[0101] ,

[0102] The unit of q is mL / min; ø is the inner diameter of the first extrusion flow channel or the second extrusion flow channel, with the unit of mm. υ x is the moving rate of the first extrusion flow channel or the second extrusion flow channel in the x-axis direction 、υ y is the moving rate of the first extrusion flow channel or the second extrusion flow channel in the y-axis direction, with the unit of mm / s. The x-axis and the y-axis are located in a plane parallel to the prepreg layer, and the x-axis and the y-axis are perpendicular to each other.

[0103] In some embodiments, the moving rate in the x-axis direction is 1 - 20 mm / s, and the moving rate in the y-axis direction is 1 - 20 mm / s.

[0104] Autoclave molding means performing hot pressing treatment on the laid prepreg layer.

[0105] In some embodiments, the hot pressing treatment may include a first heat preservation stage and a second heat preservation stage.

[0106] In some embodiments, the temperature in the first heat preservation stage can be 125°C - 135°C, and the time in the first heat preservation stage can be 0.5 h - 1.5 h.

[0107] In some embodiments, the temperature in the second heat preservation stage can be 175°C - 185°C, and the time in the second heat preservation stage can be 1.5 h - 2.5 h.

[0108] The first heat preservation stage can slowly melt the resin material of the prepreg layer itself to restore a certain viscosity, enhancing the bonding effect between prepreg layers. In the second heat preservation stage, the resin material of the prepreg layer itself can be completely cured. By performing the hot pressing treatment in the first stage and the second stage on the laid prepreg layer, the strength of the fiber-reinforced composite material can be further improved.

[0109] In some embodiments, the pressure of the hot pressing treatment can be 0.5 MPa - 0.7 MPa.

[0110] In some embodiments, the heating rate of the hot pressing treatment can be 1.0 °C / min - 1.5 °C / min.

[0111] By adjusting the pressure and heating rate of the hot pressing treatment within the above ranges, the strength of the fiber-reinforced composite material can be further improved.

[0112] The heating rate from the first heat preservation stage to the second heat preservation stage is the same as the heating rate of the hot pressing treatment.

[0113] In some embodiments, the hot pressing treatment can further include: cooling the laid prepreg layer after the second heat preservation stage to 55°C - 65°C at a rate less than or equal to 3 °C / min to obtain a self-healing fiber-reinforced composite material.

[0114] This can reduce the phenomenon of stress concentration in the self-healing fiber-reinforced composite material and improve the strength of the self-healing fiber-reinforced composite material.

[0115] In some embodiments, the preparation method can further include: performing a vacuum pumping treatment on the laid prepreg layer before the hot pressing treatment.

[0116] In some embodiments, the vacuum pumping treatment includes pumping to a vacuum degree ≤ -0.095 MPa.

[0117] The vacuum pumping treatment includes putting the laid prepreg into a vacuum bag and performing a vacuum pumping treatment on the vacuum bag. By the vacuum pumping treatment, the air between the prepreg layers can be discharged, further increasing the bonding force between the prepreg layers.

[0118] Embodiment

[0119] The following examples describe the content of the present application in more detail. These examples are for illustrative purposes only, as various modifications and variations within the scope of the present application are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on mass, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and all instruments used in the examples are commercially available.

[0120] Example 1

[0121] (1) The shell material photocurable resin material is an epoxy-based photocurable resin, and the core material polymer material is a room-temperature curing two-component epoxy resin;

[0122] (2) Design the vascular arrangement network, input it into the program of the 3D printing device, and adjust the printing parameters according to the state of the repair fluid;

[0123] (3) Store the shell material photocurable resin and the core material repair fluid in the cartridges respectively. Install a microfluidic chip integrated with an extrusion needle at the lower part of the cartridge. Use the multi-channels inside the microfluidic chip to regulate the shell material and the core material to realize the printing and forming of the vascular with a core-shell structure; The structure of the microfluidic chip is as follows Figure 2 shown. The size of the input channel is 3 mm, the inner diameter of the first extrusion channel is 0.8 mm, and the inner diameter of the second extrusion channel is 1.1 mm. The moving rate in the x-axis direction is 5 mm / s, the moving rate in the y-axis direction is 5 mm / s, the extrusion rate of the shell material is 150.7 μL / min, the extrusion rate of the core material is 134.26 μL / min, and at the set prepreg layer, print the vascular with a core-shell structure. Use a two-component repair fluid, that is, use a dual-core layer channel, and perform switching extrusion to print a vascular network containing a two-component repair fluid;

[0124] (4) The laid prepreg is evacuated at room temperature until the vacuum degree reaches ≤ -0.095 MPa; then placed in an autoclave, pressurized to 0.6 MPa ± 0.02 MPa at room temperature, and then heated at a rate of 1.0 °C / min - 1.5 °C / min, and kept at 130 °C ± 5 °C for 1.0 h ± 0.5 h; then continue to heat up to 180 °C ± 5 °C, keep it for 2.0 h ± 0.5 h, and then cool it to 60 °C at a speed not greater than 3 °C / min, then remove the vacuum and take out the sample to obtain a self-healing fiber-reinforced composite material.

[0125] Example 2

[0126] Except that the inner diameter of the first extrusion channel is 0.6 mm and the inner diameter of the second extrusion channel is 0.8 mm, and the extrusion rate of the shell material is 84.78 μL / min and the extrusion rate of the core material is 66.1 μL / min, the preparation method of the remaining self-healing fiber-reinforced composite material is the same as that of Example 1.

[0127] The self-healing fiber-reinforced composite material can be prepared through both Example 1 and Example 2.

[0128] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A preparation method of a self-healing fiber-reinforced composite material based on a 3D-printed vascular network, comprising: providing a shell material and a core material; designing a vascular arrangement network and inputting the vascular arrangement network into the program of a 3D printing device; placing the shell material and the core material in a cartridge and inputting them into a microfluidic chip. Using 3D printing, print vascular tubes containing a repair agent on a prepreg layer to obtain a laid prepreg layer; the microfluidic chip includes an input channel, a first extrusion channel, and a second extrusion channel; the input channel includes a first input channel and a second input channel, the number of the first input channels is multiple, the inner diameter of the input channel is 0.5 mm - 3 mm; the inner diameter of the first extrusion channel is 0.2 mm - 2.5 mm; the inner diameter of the second extrusion channel is 0.4 mm - 3 mm; the extrusion rate of the shell material is 1.88 - 5887.5 μL / min, and the extrusion rate of the core material is 56.56 - 2590.5 μL / min; the vascular network is a one-dimensional structure and / or a two-dimensional structure, and the vascular network is a tiled structure in the prepreg layer; performing autoclave molding on the laid prepreg layer to obtain a self-healing fiber-reinforced composite material.

2. The preparation method according to claim 1, characterized in that, A micro mixer is provided inside the input channel; and / or, the cross-sectional shapes of the input channel, the first extrusion channel, and the second extrusion channel are independently selected from a square, a circle, a triangle, and an ellipse.

3. The preparation method according to claim 1, characterized in that, The step of printing vascular tubes containing a repair agent on the prepreg layer by using 3D printing includes: setting the position of the vascular tubes in the prepreg layer according to the total thickness of the prepreg layer; printing a layer of vascular tubes every 4 - 8 prepreg layers.

4. The preparation method according to claim 1, characterized in that, The formula for the extrusion rate q is: ， The unit of q is mL / min; ø is the inner diameter of the first extrusion channel or the second extrusion channel, with the unit of mm. υ x is the moving rate of the first extrusion channel or the second extrusion channel in the x-axis direction 、υ y is the moving rate of the first extrusion channel or the second extrusion channel in the y-axis direction, with the unit of mm / s.

5. The preparation method according to claim 4, characterized in that, The moving rate in the x-axis direction is 1 - 20 mm / s, and the moving rate in the y-axis direction is 1 - 20 mm / s.

6. A self-healing fiber-reinforced composite material based on a 3D-printed vascular network, characterized in that, Prepared by the preparation method according to any one of claims 1 - 5, the self-healing fiber-reinforced composite material has a 3D-printed vascular network inside, the vascular network is a one-dimensional structure and / or a two-dimensional structure, and the vascular network is a tiled structure in the prepreg layer; the vascular tube includes a shell material and a core material located inside the shell material, and the core material includes a repair agent.

7. According to the self-healing fiber-reinforced composite material of claim 6, wherein the shell material includes a photocurable resin; the repair agent includes a polymer; the polymer includes one or more of a single-component or two-component epoxy resin, a bismaleimide resin, a phenolic resin, and an unsaturated polyester resin.

8. The self-healing fiber-reinforced composite material according to claim 6, wherein, The outer diameter of the vascular tube is 0.4 mm - 3 mm; and / or, the inner diameter of the vascular tube is 0.2 mm - 2.5 mm.

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