Self-repairing fiber reinforced composite material based on 3D printing vessel network and preparation method thereof

Abstract

The invention relates to a self-repairing fiber reinforced composite material based on a 3D printing vessel network and a preparation method of the self-repairing fiber reinforced composite material. The preparation method comprises the following steps: providing a shell layer material and a core layer material; designing a vessel arrangement network, and inputting the vessel arrangement network into a program of the 3D printing equipment; putting the shell layer material and the core layer material into a charging barrel, inputting the charging barrel into a micro-fluidic chip, and printing a pulse tube containing a repairing agent on the prepreg layer by utilizing 3D printing, so as to obtain the laid prepreg layer; and carrying out autoclave molding on the laid prepreg layer to obtain the self-repairing fiber reinforced composite material. According to the preparation method of the self-repairing fiber-reinforced composite material based on the 3D printing pulse tube network, random arrangement of pulse tubes can be achieved, the obtained self-repairing fiber-reinforced composite material has an integrally-formed structure, when the fiber-reinforced composite material is damaged, the coverage range of a repairing agent after seepage is enlarged, and the repairing effect of the fiber-reinforced composite material is improved. And a repair reaction can be generated more quickly and stably, so that the repair effect is improved.

Description

Technical Field

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

[0002] The self-repairing fiber-reinforced composite material containing vascular tubes is a composite material that has an autonomous, stimulus-triggered self-repairing system built inside the composite material. It is generally prepared by the pre-buried wire removal method and the vascular tube filling method. When the composite material is damaged, the repair fluid in the flow channel will penetrate into the damaged area and react to achieve the repair effect. However, the current technology is cumbersome to operate, the arrangement of the vascular tubes is greatly affected by human factors, and the stability and repeatability of the repair effect are poor; and the arrangement of the vascular tubes has limitations, and usually only a horizontal and vertical layout can be achieved, which limits the coverage of the repair fluid after the vascular tubes are impacted or damaged, and reduces the repair effect. Summary of the invention

[0003] The present application provides a self-repairing fiber-reinforced composite material based on a 3D printed vascular network and a preparation method thereof, which can realize arbitrary arrangement of blood vessels. When the fiber-reinforced composite material is damaged, the coverage of the repair agent after leakage is increased, and the repair reaction is generated faster and more stably, thereby improving the repair effect.

[0004] In the first aspect, the present application provides a method for preparing a self-repairing fiber-reinforced composite material based on a 3D printed vascular network, comprising: providing a shell layer material and a core layer material; designing a vascular arrangement network, and inputting the vascular arrangement network into a program of a 3D printing device; placing the shell layer material and the core layer material in a barrel, inputting them into a microfluidic chip, and using 3D printing to print out vascular ducts containing a repair agent in a prepreg layer to obtain a laid prepreg layer; and autoclaving the laid prepreg layer to obtain a self-repairing 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 disposed inside the input flow channel.

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

[0011] In some embodiments, the step of printing a vascular tube containing a repair agent in a prepreg layer using 3D printing includes: setting a position of the vascular tube in the prepreg layer according to a total thickness of the prepreg layer; and printing a layer of vascular tube every 4-8 prepreg layers.

[0012] In some embodiments, the extrusion rate of the shell 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 extrusion rate q is given by: , The unit of q is mL / min; ø is the inner diameter of the first extrusion channel or the second extrusion channel, the unit is mm, υ x is the moving speed of the first extrusion channel or the second extrusion channel in the x-axis direction ,υ y It is the moving speed of the first extrusion flow channel or the second extrusion flow channel in the y-axis direction, in mm / s.

[0015] In some embodiments, the moving speed in the x-axis direction is 1-20 mm / s, and the moving speed in the y-axis direction is 1-20 mm / s.

[0016] In a second aspect, the present application provides a self-repairing fiber-reinforced composite material based on a 3D printed vascular network, wherein the interior of the self-repairing fiber-reinforced composite material has a 3D printed vascular network; the vascular network 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.

[0017] In some embodiments, the shell material includes a photocurable resin.

[0018] 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.

[0019] In some embodiments, the outer diameter of the vessel is 0.4 mm-3 mm.

[0020] In some embodiments, the inner diameter of the vessel is 0.2 mm-2.5 mm.

[0021] The embodiment of the present application combines the microfluidic chip with 3D printing technology to realize the arbitrary arrangement of the vascular network, and the obtained self-repairing 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, under the premise of minimizing the impact on the inside of the fiber-reinforced composite material, the application demand for the long-term service of the fiber-reinforced composite material is strengthened, the reliability of the fiber-reinforced composite material structure is improved, and the service life is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present application. In addition, the same reference numerals are used to represent the same components throughout the accompanying drawings.

[0023] Figure 1 This is a diagram showing the arrangement of a vascular network on the surface of a fiber-reinforced composite material provided in one embodiment of the present application; Figure 2 A schematic diagram of the structure of a microfluidic chip provided in some embodiments of the present application; Figure 3 A schematic flow chart of a method for preparing a self-repairing fiber-reinforced material provided in some embodiments of the present application.

[0024] 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

[0025] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings, but it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application.

[0026] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0027] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0028] In the description of the embodiments of the present application, the term "and / or" is merely a term used to describe the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0029] In the description of the embodiments of the present application, the term "plurality" refers to more than two (including two).

[0030] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0031] Fiber reinforced composite materials are widely used in many fields, such as aerospace, transportation and other industries, due to their advantages such as light weight and high strength. However, fiber reinforced composite materials will inevitably produce some damage during use, especially invisible damage, which is difficult to be discovered in time. However, the damaged area will greatly reduce the overall mechanical properties of the fiber reinforced composite material, limiting its application.

[0032] In order to improve the service life of fiber-reinforced composites, researchers embedded a vascular network inside the fiber-reinforced composites to obtain a self-repairing fiber-reinforced composite material containing vasculars, which can achieve automatic repair after damage.

[0033] Conventional preparation methods for composite materials that use hollow vessels for self-repair are generally divided into two types: one is the pre-embedded wire removal method, that is, the pre-embedded wire is embedded in the prepreg molding process, and the pre-embedded wire is extracted with the help of external force after molding, and then the repair liquid is injected to seal. This method is difficult to operate, and extracting the pre-embedded wire will seriously affect the interlayer bonding strength of the prepreg, and it is not easy to operate. The second is to fill the hollow vessels containing the repair liquid, first using the capillary effect to store the repair liquid in the hollow vessels, and then laying the hollow vessels containing the repair liquid into the prepreg. The operation is cumbersome and the amount of the repair liquid is difficult to control.

[0034] In addition, in the related art, placing the hollow fiber glass tube in the fiber reinforced composite material may affect the strength of the fiber reinforced composite material, and the layering is difficult and difficult to replicate.

[0035] In view of this, the present application provides a self-repairing fiber-reinforced composite material based on a 3D printed vascular network and a preparation method thereof, which can realize arbitrary arrangement of blood vessels. When the fiber-reinforced composite material is damaged, the coverage range after the repair agent seeps out is increased, and the repair reaction is generated faster and more stably, thereby improving the repair effect.

[0036] The present application provides a self-repairing fiber-reinforced composite material based on a 3D printed vascular network, such as Figure 1 As shown, the self-repairing fiber-reinforced composite material has a 3D-printed vascular network inside; The vessel comprises a shell material and a core material located inside the shell material, wherein the core material comprises a repair agent.

[0037] It can be understood that the blood vessel in the embodiment of the present application has a hollow structure, and the repair agent is filled in the interior of the hollow structure.

[0038] The embodiment of the present application obtains a vascular network inside the self-repairing fiber-reinforced material through 3D printing technology, and can realize any arrangement of the vascular. The vascular includes a shell material and a core material located inside the shell material, and the core material includes a repair agent. The vascular, as a sensing path, can sense damage such as interlayer peeling and matrix microcracks caused by impact on the fiber-reinforced composite material. Since connectivity is established between the vascular and the damaged area, the repair agent is triggered to be transmitted to the damaged area to realize the self-repair of the fiber-reinforced composite material. When the fiber-reinforced composite material is damaged, the coverage of the repair agent after leakage is increased, and the repair reaction is generated faster and more stably, thereby improving the repair effect.

[0039] In some embodiments, the vascular network may be a one-dimensional structure or a two-dimensional structure.

[0040] Normally, the filling shape of the vascular is horizontal and vertical, which limits the diffusion range of the repair agent after the fiber-reinforced composite material is damaged, further affecting the reaction of the repair agent. Using 3D printing technology to print the vascular with the repair agent can make the path of the vascular more flexible, that is, to achieve a criss-cross arrangement of the vascular network in one-dimensional and two-dimensional layers, promote the exudation of the repair agent after the vascular is damaged, and accelerate the repair reaction.

[0041] In some embodiments, the fiber reinforced composite material is arranged in layers, and the venous tube is located between the layers of the fiber reinforced composite material. For example, when the fiber reinforced composite material is two layers, the venous tube is located between the layers of adjacent fiber reinforced composite materials. When the fiber reinforced composite material is three or more layers, the venous tube may be located between any two layers of the fiber reinforced composite material, that is, in this case, there may be a situation where no venous tube is provided between the layers of two adjacent layers of the fiber reinforced composite material.

[0042] The embodiment of the present application prints blood vessels through 3D printing technology, which can make the selection range of shell layer materials and core layer materials wider.

[0043] In some embodiments, the shell material may include a photocurable resin.

[0044] Photocurable resin has good compatibility with fiber-reinforced composite materials, thereby enhancing the interlayer bonding strength of fiber-reinforced composite materials.

[0045] In some embodiments, the photocurable resin may include one or more of acrylate photocurable resin, epoxy photocurable resin, polyester acrylate photocurable resin, silicone photocurable resin and acrylic photocurable resin. By using the photocurable resin, the shell material can be cured by ultraviolet light, and the preparation process is more convenient.

[0046] In some embodiments, the shell material may further include additives, such as functional materials such as ceramic powder and metal powder.

[0047] In some embodiments, the repair agent may be a single-component repair agent or a two-component repair agent.

[0048] In some embodiments, the healing agent may include a polymer.

[0049] In some embodiments, the polymer may include one or more of a one-component or two-component epoxy resin, a bismaleimide resin, a phenolic resin, and an unsaturated polyester resin.

[0050] By selecting the above polymers, when the composite material is damaged, the polymer can react quickly and have a good bonding effect with the prepreg, thereby achieving the best repair response.

[0051] 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.

[0052] In some embodiments, the outer diameter of the vessel can be 0.4 mm-3 mm, for example, 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 consisting of any two of the above values.

[0053] In some embodiments, the inner diameter of the vessel can be 0.2 mm-2.5 mm, for example, 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 consisting of any two of the above values.

[0054] By setting the inner diameter and outer diameter of the vessel within the above range, the mass ratio of the shell material and the core material can be adjusted within an appropriate range, which can not only achieve a thinner shell thickness so that when the composite material is damaged by impact, the repair agent in the vessel can seep into the interior of the composite material, but also allow sufficient repair agent to fill the vessel, thereby achieving the best repair effect.

[0055] The present application provides a method for preparing a self-repairing fiber-reinforced composite material based on a 3D printed vascular network. Figure 3 A schematic diagram of a process for preparing a self-repairing fiber-reinforced material provided in some embodiments of the present application, such as Figure 3 As shown, the preparation method comprises the following steps: S10: providing shell material and core material; S20: designing a vascular arrangement network, and inputting the vascular arrangement network into a program of a 3D printing device; S30: placing the shell layer material and the core layer material in a barrel, inputting them into the microfluidic chip, and printing the vascular tube containing the repair agent on the prepreg layer by 3D printing to obtain a laid prepreg layer; S40: The laid prepreg layer is subjected to hot-pressing molding to obtain a self-repairing fiber-reinforced composite material.

[0056] The embodiment of the present application combines the microfluidic chip with 3D printing technology to realize the arbitrary arrangement of the vascular network, and the obtained self-repairing 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, under the premise of minimizing the impact on the inside of the fiber-reinforced composite material, the application demand for the long-term service of the fiber-reinforced composite material is strengthened, the reliability of the fiber-reinforced composite material structure is improved, and the service life is extended.

[0057] In some embodiments, the step of arranging the vein inside the prepreg layer may include: printing the vein on the surface of the prepreg layer and then laying another prepreg layer on the surface.

[0058] It can be understood that the veins in the prepreg layer are in a flat structure, and the fiber material is also in a flat structure, thereby reducing damage to the fibers during the setting of the veins.

[0059] The embodiment of the present application combines 3D printing and microfluidic technology to integrally form a vascular network containing a repair fluid, that is, the vascular sealing can be achieved by printing only shell material at the head and tail ends of the vascular vessel, thereby reducing the processes of filling hollow vessels by capillary action and sealing the vessels individually, and the preparation process is simple and convenient.

[0060] The embodiment of the present application utilizes a combination of 3D printing and microfluidic technology to integrally print a vascular network having a core-shell structure and precisely control the amount of repair fluid in the vascular vessel.

[0061] In some embodiments, the microfluidic chip can also be prepared by 3D printing technology.

[0062] Before preparing the microfluidic chip, it is necessary to test and adjust the exposure parameters of the 3D printing equipment so that the prepared microfluidic chip structure does not collapse, block holes, and other problems.

[0063] In some embodiments, the material of the microfluidic chip may be a polymer material, such as polydimethylsiloxane.

[0064] In addition, microfluidic chips can also be manufactured using standard microelectromechanical systems (MEMS) processes or soft lithography techniques, allowing the flow channels in microfluidic chips to be precisely defined on a micrometer to millimeter scale.

[0065] Figure 2 A schematic diagram of the structure of a microfluidic chip provided in some embodiments of the present application, such as Figure 2 shown.

[0066] 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.

[0067] The flow channel design inside the microfluidic chip can be used to regulate the shell layer material and the core layer material, and print blood vessels with a core-shell structure.

[0068] 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.

[0069] In some embodiments, the microfluidic chip includes an input portion 101 and an extrusion portion 201. The first extrusion channel 21 and the second extrusion channel 22 are located in the extrusion portion 201, and the input channel 10 is located in the input portion 101.

[0070] 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 core layer material, and the second input channel 12 is used to input shell layer material.

[0071] The shell material and the core material are stored in a shell material barrel and a core material barrel respectively. The outlet of the shell material barrel is connected to the second input channel of the microfluidic chip, and the outlet of the core material barrel is connected to the first input channel.

[0072] The input flow channel of the microfluidic chip is connected to the joint of the barrel of the corresponding 3D printing device, and the connection method includes but is not limited to adhesive bonding and clamp-rubber gasket sealing connection.

[0073] In some embodiments, the extrusion needle of the microfluidic chip is integrated with the body of the microfluidic chip. The extrusion needle is the first extrusion flow channel and the second extrusion flow channel of the microfluidic chip. This can reduce the replacement of the printing needle during 3D printing, realize the free replacement of single-component or double-component core layer materials, and form the vascular tube of the core-shell structure in one go.

[0074] The structure and size of the microfluidic chip can be designed according to actual needs.

[0075] In some embodiments, the inner diameter of the input flow channel 10 may be 0.5 mm-3 mm, for example, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a range consisting of any two of the above values.

[0076] In some embodiments, the inner diameter of the first extrusion channel 21 can be 0.2mm-2.5mm, for example, it can be 0.2mm, 0.3mm, 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm, or a range consisting of any two of the above values.

[0077] In some embodiments, the inner diameter of the second extrusion channel 22 can be 0.4mm-3mm, for example, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, or a range consisting of any two of the above values.

[0078] When the inner diameters of the first extrusion flow channel and the second extrusion flow channel are within the above range, the size of the obtained vein can be matched with the thickness of the prepreg layer, thereby further improving the strength of the fiber reinforced composite material.

[0079] In some embodiments, the input flow channel includes a first input flow channel 11 and a second input flow channel 12 .

[0080] In some embodiments, the number of the first input flow channels 11 may be one or more.

[0081] In the case where there are multiple first input channels, it is possible to switch between multiple barrels and input channels of the 3D printer during 3D printing. Without replacing the barrel or print head, it is possible to freely replace single-component and two-component core layer materials, and form core-shell structures of multiple core layer materials at one time. In the case where the repair agent in the vascular vessel is single-component, only the first input channel can be used without using the second input channel. In the case where the repair agent in the vascular vessel is two-component, the first input channel and the second input channel can be used at the same time. The embodiment of the present application combines 3D printing and microfluidic technology, which is more flexible to operate and can realize the preparation of self-repairing composite materials by integrating a single-component repair agent or a two-component repair agent with a shell material.

[0082] In some embodiments, a micro mixer may be disposed inside the input flow channel 10 .

[0083] The micro mixer can achieve the mixing of core materials or shell materials with shear thinning properties, and can also achieve the mixing of high molecular polymer materials with high viscosity.

[0084] Exemplarily, the micro-mixer may be a spiral mixing element disposed inside the flow channel along the axial direction of the flow channel.

[0085] In some embodiments, the shapes of the cross sections of the input channel 10 , the first extrusion channel 21 , and the second extrusion channel 22 can be independently selected from square, circle, triangle, and ellipse.

[0086] In some embodiments, the step of printing a vascular tube containing a repair agent in a prepreg layer using 3D printing may include: setting a position of the vascular tube in the prepreg layer according to a total thickness of the prepreg layer; and printing a layer of vascular tube every 4-8 prepreg layers.

[0087] In some embodiments, the extrusion rate of the shell material can be 1.88-5887.5 μL / min.

[0088] In some embodiments, the extrusion rate of the core layer material can be 56.56-2590.5 μL / min.

[0089] The embodiment of the present application sets the extrusion rates of the core layer material and the shell layer material within the above range, thereby further adjusting the thickness of the shell layer material in the vessel and the filling amount of the core layer material within a suitable range, thereby ensuring that the subsequently formed composite material achieves the best repair effect.

[0090] The extrusion rate is affected by the inner diameter of the flow channel and the movement rate.

[0091] In some embodiments, the extrusion rate q is given by: , The unit of q is mL / min; ø is the inner diameter of the first extrusion channel or the second extrusion channel, the unit is mm, υ x is the moving speed of the first extrusion channel or the second extrusion channel in the x-axis direction ,υ y is the moving speed of the first extrusion flow channel or the second extrusion flow channel in the y-axis direction, in 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.

[0092] In some embodiments, the moving speed in the x-axis direction is 1-20 mm / s, and the moving speed in the y-axis direction is 1-20 mm / s.

[0093] Autoclave molding is to heat and press the laid prepreg layers.

[0094] In some embodiments, the autoclave process may include a first soaking stage and a second soaking stage.

[0095] In some embodiments, the temperature of the first insulation stage may be 125° C.-135° C., and the duration of the first insulation stage may be 0.5 h-1.5 h.

[0096] In some embodiments, the temperature of the second insulation stage may be 175° C.-185° C., and the duration of the second insulation stage may be 1.5 h-2.5 h.

[0097] The first heat preservation stage can slowly melt the resin material of the prepreg layer itself to restore a certain viscosity, thereby improving the bonding effect between the prepreg layers. In the second heat preservation stage, the resin material of the prepreg layer itself can be completely solidified. By performing the first and second stage hot pressing treatments on the laid prepreg layers, the strength of the fiber-reinforced composite material can be further improved.

[0098] In some embodiments, the pressure of the autoclave treatment may be 0.5 MPa-0.7 MPa.

[0099] In some embodiments, the heating rate of the hot pressing process may be 1.0° C. / min-1.5° C. / min.

[0100] By adjusting the pressure and heating rate of the hot pressing treatment within the above range, the strength of the fiber reinforced composite material can be further improved.

[0101] 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.

[0102] In some embodiments, the hot pressing treatment may further include: cooling the laid prepreg layer after the second heat preservation stage treatment to 55° C.-65° C. at a rate of less than or equal to 3° C. / min to obtain a self-repairing fiber reinforced composite material.

[0103] This can reduce the stress concentration phenomenon in the self-repairing fiber reinforced composite material and improve the strength of the self-repairing fiber reinforced composite material.

[0104] In some embodiments, the preparation method may further include: performing a vacuum treatment on the laid prepreg layer before the hot pressing treatment.

[0105] In some embodiments, the vacuuming process includes evacuating to a vacuum degree of ≤-0.095 MPa.

[0106] The vacuum treatment includes placing the laid prepreg into a vacuum bag and vacuuming the vacuum bag. The vacuum treatment can exhaust the air between the prepreg layers and further increase the bonding strength between the prepreg layers.

[0107] Example The following examples describe the content of the present application in more detail, and these examples are only for illustrative purposes, because it is obvious to those skilled in the art that various modifications and variations are made within the scope of the present application. 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 the instruments used in the examples are commercially available.

[0108] Example 1 (1) The light-curing resin material of the shell layer is an epoxy light-curing resin, and the polymer material of the core layer is a room temperature curing two-component epoxy resin; (2) Design the vascular arrangement network, input it into the program of the 3D printing equipment, and adjust the printing parameters according to the state of the repair fluid; (3) The photocurable resin of the shell material and the repair liquid of the core material are stored in the barrel respectively, and a microfluidic chip integrated with the extrusion needle is installed at the bottom of the barrel. The shell material and the core material are regulated by the multi-channel inside the microfluidic chip to realize the printing and forming of the core-shell structured blood vessels; the structure of the microfluidic chip is as follows Figure 2As shown, the input channel size is 3mm, while the inner diameter of the first extrusion channel is 0.8mm, and the inner diameter of the second extrusion channel is 1.1mm. The moving rate in the x-axis direction is 5mm / s, the moving rate in the y-axis direction is 5mm / s, the extrusion rate of the shell material is 150.7µL / min, and the extrusion rate of the core layer material is 134.26µL / min. In the set prepreg layer, the vascular printing of the core-shell structure is performed. Use a two-component repair liquid, that is, use a dual-core layer flow channel, switch extrusion, and print a vascular network containing a two-component repair liquid; (4) The laid prepreg is evacuated at room temperature to a vacuum degree of ≤-0.095MPa; then placed in an autoclave, pressurized to 0.6MPa±0.02MPa at room temperature, heated at a rate of 1.0℃ / min-1.5℃ / min, and kept at 130℃±5℃ for 1.0h±0.5h; then the temperature is continued to be raised to 180℃±5℃, kept at this temperature for 2.0h±0.5h, and then cooled to 60℃ at a rate of no more than 3℃ / min, the vacuum is removed and the sample is taken out to obtain a self-healing fiber reinforced composite material.

[0109] Example 2 The preparation method of the self-repairing fiber reinforced composite material is the same as that of Example 1 except that the inner diameter of the first extrusion flow channel is 0.6 mm and the inner diameter of the second extrusion flow channel is 0.8 mm. The extrusion rate of the shell layer material is 84.78 μL / min and the extrusion rate of the core layer material is 66.1 μL / min.

[0110] Through both Example 1 and Example 2, a self-repairing fiber-reinforced composite material can be prepared.

[0111] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; 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 included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for preparing a self-repairing fiber-reinforced composite material based on a 3D printed vascular network, comprising: Provide shell materials and core materials; Designing a vascular arrangement network and inputting the vascular arrangement network into a program of a 3D printing device; The shell layer material and the core layer material are placed in a barrel, input into a microfluidic chip, and 3D printing is used to print a vascular tube containing a repair agent on the prepreg layer to obtain a laid prepreg layer; The laid prepreg layer is subjected to autoclave molding to obtain a self-repairing fiber reinforced composite material.

2. The preparation method according to claim 1, characterized in that: The microfluidic chip comprises an input channel, a first extrusion channel, and a second extrusion channel; The inner diameter of the input flow channel is 0.5mm-3mm; The inner diameter of the first extrusion flow channel is 0.2 mm-2.5 mm; The inner diameter of the second extrusion flow channel is 0.4 mm-3 mm.

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

4. The preparation method according to claim 1, characterized in that: The step of printing a vascular tube containing a repairing agent in the prepreg layer by 3D printing comprises: setting a position of the vascular tube in the prepreg layer according to the total thickness of the prepreg layer; Print a layer of veins every 4-8 prepreg layers.

5. The preparation method according to claim 2, characterized in that: The extrusion rate of the shell material is 1.88-5887.5 µL / min; and / or, The extrusion rate of the core layer material is 56.56-2590.5 μL / min.

6. The preparation method according to claim 5, 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, the unit is mm, υ x is the moving speed of the first extrusion channel or the second extrusion channel in the x-axis direction ,υ y It is the moving speed of the first extrusion flow channel or the second extrusion flow channel in the y-axis direction, in mm / s.

7. The preparation method according to claim 6, characterized in that: The moving speed in the x-axis direction is 1-20 mm / s, and the moving speed in the y-axis direction is 1-20 mm / s.

8. A self-repairing fiber-reinforced composite material based on a 3D printed vascular network, characterized in that: The self-repairing fiber-reinforced composite material has a 3D-printed vascular network inside; The vessel comprises a shell material and a core material located inside the shell material, wherein the core material comprises a repair agent.

9. The self-repairing fiber-reinforced composite material according to claim 8, characterized in that: The shell material includes a light-curable 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.

10. The self-repairing fiber-reinforced composite material according to claim 8, characterized in that: The outer diameter of the blood vessel is 0.4 mm to 3 mm; and / or, The inner diameter of the blood vessel is 0.2 mm-2.5 mm.

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