Epoxy resin matrix, composite material and preparation method thereof

Abstract

The invention discloses an epoxy resin matrix, a composite material and a preparation method thereof, and relates to the technical field of composite materials. The mass of each component of the epoxy resin matrix accounts for the total mass of the epoxy resin matrix as follows: 75-90% of first epoxy resin; 4-16% of a curing agent; 3-12% of microcapsules; the capsule wall of the microcapsule comprises melamine-urea resin, and the capsule core of the microcapsule comprises silane coupling agent modified second epoxy resin. The epoxy resin matrix still has good self-repairing capacity after being cured, the durability of the material is improved, the material is more reliable and durable in application, and the concept of sustainable development is met.

Description

Technical Field

[0001] The present application relates to the technical field of composite materials, and in particular to an epoxy resin matrix, a composite material and a preparation method thereof. Background Art

[0002] Fiber reinforced composite materials are widely used in aerospace, automobile, navigation and other fields due to their light weight and high strength. However, during the use of fiber reinforced composite materials, cracks and damage caused by external forces and environmental factors will affect the service life and performance of the materials. Therefore, how to achieve self-repair of fiber reinforced composite materials is of great significance to improving the performance of composite materials and extending the service life of composite materials. Summary of the invention

[0003] In order to solve the above technical problems, the present application aims to provide an epoxy resin matrix, a composite material and a preparation method thereof. The cured product of the epoxy resin matrix has excellent self-healing ability, increases the durability of the material, makes it more reliable and durable in application, and conforms to the concept of sustainable development.

[0004] According to a first aspect of the present application, an epoxy resin matrix is ​​provided, wherein the mass percentage of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0005] First epoxy resin 75-90%;

[0006] Curing agent 4-16%;

[0007] Microcapsules 3-12%;

[0008] The capsule wall of the microcapsule comprises melamine-urea-formaldehyde resin, and the capsule core of the microcapsule comprises a second epoxy resin modified by a silane coupling agent.

[0009] In some embodiments of the present application, the mass ratio of the first epoxy resin to the microcapsule is 6.3-26.7:1.

[0010] In some embodiments of the present application, the microcapsule includes a first microcapsule particle and a second microcapsule particle, the first microcapsule particle has a particle size of 40-60 μm, and the second microcapsule particle has a particle size of 90-110 μm.

[0011] In some embodiments of the present application, the mass ratio of the first microcapsule particles to the second microcapsule particles is 5:1.2-4.8.

[0012] In some embodiments of the present application, the first epoxy resin includes one or a combination of bisphenol A epoxy resin and bisphenol F epoxy resin;

[0013] The curing agent includes triethylenetetramine;

[0014] The second epoxy resin includes bisphenol A type epoxy resin.

[0015] In some embodiments of the present application, when the first epoxy resin includes bisphenol A epoxy resin and bisphenol F epoxy resin, the mass ratio of the bisphenol A epoxy resin to the bisphenol F epoxy resin is 1.5-5.5:1.

[0016] In some embodiments of the present application, the epoxy resin matrix further includes 0.5-2% of an accelerator.

[0017] In some embodiments of the present application, the promoter includes one or a combination of aniline and triethanolamine.

[0018] According to a second aspect of the present application, a composite material is provided, comprising carbon fiber and the epoxy resin matrix as described above, wherein the weight parts of the components of the composite material are expressed as follows:

[0019] Epoxy resin matrix 30-55 parts by mass;

[0020] 50-70 parts by mass of carbon fiber.

[0021] According to a third aspect of the present application, a method for preparing a composite material is provided. The method for preparing a composite material is used to prepare the composite material as described above, and the method comprises:

[0022] Dissolving the epoxy resin matrix in an organic solvent to obtain an epoxy resin matrix solution;

[0023] Infiltrating the carbon fiber with the epoxy resin matrix solution to obtain an intermediate material;

[0024] The intermediate material is cured under preset conditions to obtain the composite material.

[0025] The technical solution provided by this application may have the following beneficial effects:

[0026] The present application introduces microcapsules into an epoxy resin matrix. When the epoxy resin matrix material is damaged and cracks are generated, the microcapsules at the crack tip rupture due to concentrated stress, so that the silane coupling agent-modified second epoxy resin in the capsule core is released. Under the capillary action, the microcapsules can penetrate into the cracks of the material and react with the curing agent dispersed in the epoxy resin matrix to close the crack surface to achieve self-repair, thereby increasing the durability of the material, making it more reliable and durable in application, and conforming to the concept of sustainable development.

[0027] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0029] Figure 1 The present invention is a flow chart of a method for preparing a composite material according to an exemplary embodiment. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the present application will be clearly and completely described below in combination with the embodiments of the present application and the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other.

[0031] The present application provides an epoxy resin matrix, wherein the mass percentage of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows: 75-90% of the first epoxy resin; 4-16% of the curing agent; 3-12% of the microcapsule; the capsule wall of the microcapsule includes melamine-urea-formaldehyde resin, and the capsule core of the microcapsule includes a second epoxy resin modified by a silane coupling agent. The present application introduces microcapsules into the epoxy resin matrix, and when the epoxy resin matrix material is damaged and cracks are generated, the microcapsules at the crack tip are broken due to concentrated stress, so that the second epoxy resin modified by the silane coupling agent in the capsule core is released, and can penetrate into the cracks of the material under capillary action, and undergo a curing reaction with the curing agent dispersed in the epoxy resin matrix, so that the crack surface is closed to achieve self-repair, thereby increasing the durability of the material, making it more reliable and durable in application, and conforming to the concept of sustainable development.

[0032] Some specific implementation modes described below are intended to facilitate those skilled in the art to understand the present embodiment, and the present embodiment is not limited to some specific implementation modes described below.

[0033] In an exemplary embodiment, the present application provides an epoxy resin matrix, and the percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0034] First epoxy resin 75-90%;

[0035] Curing agent 4-16%;

[0036] Microcapsules 3-12%;

[0037] The capsule wall of the microcapsule comprises melamine-urea-formaldehyde resin, and the capsule core of the microcapsule comprises a second epoxy resin modified by a silane coupling agent.

[0038] In this embodiment, microcapsules are introduced into the epoxy resin matrix. When the epoxy resin matrix material is damaged and cracks are generated, the microcapsules at the crack tip rupture due to concentrated stress, so that the silane coupling agent-modified second epoxy resin in the capsule core is released. Under the capillary action, it can penetrate into the cracks of the material and undergo a curing reaction with the curing agent dispersed in the epoxy resin matrix, thereby closing the crack surface and achieving self-repair.

[0039] Among them, the microcapsule uses melamine-urea-formaldehyde resin as the capsule wall. After curing, the melamine-urea-formaldehyde resin can form a uniform and dense film, which can effectively wrap the capsule core to avoid its premature release and lose the function of repairing cracks. Using a silane coupling agent to modify the second epoxy resin as the capsule core can make the capsule core have better storage stability, and can maintain its performance unchanged for a long time, thereby prolonging its self-repairing effect. Among them, the silane coupling agent can be, for example, γ-aminopropyltriethoxysilane. The microcapsule can be prepared by spray drying, air suspension, interfacial polymerization and other methods, and can also be obtained commercially, for example, it can be purchased from Hangzhou Yingxing New Materials Co., Ltd.

[0040] For example, in one embodiment, the percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0041] First epoxy resin 75%;

[0042] Curing agent 16%;

[0043] Microcapsules 9%;

[0044] The capsule wall of the microcapsule comprises melamine-urea-formaldehyde resin, and the capsule core of the microcapsule comprises a second epoxy resin modified by a silane coupling agent.

[0045] In another embodiment, the percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0046] First epoxy resin 87%;

[0047] Curing agent 10%;

[0048] Microcapsules 3%;

[0049] The capsule wall of the microcapsule comprises melamine-urea-formaldehyde resin, and the capsule core of the microcapsule comprises a second epoxy resin modified by a silane coupling agent.

[0050] In another embodiment, the percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0051] First epoxy resin 82%;

[0052] Curing agent 6%;

[0053] Microcapsules 12%;

[0054] The capsule wall of the microcapsule comprises melamine-urea-formaldehyde resin, and the capsule core of the microcapsule comprises a second epoxy resin modified by a silane coupling agent.

[0055] In another embodiment, the percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0056] First epoxy resin 90%;

[0057] Curing agent 4%;

[0058] Microcapsules 6%;

[0059] The capsule wall of the microcapsule comprises melamine-urea-formaldehyde resin, and the capsule core of the microcapsule comprises a second epoxy resin modified by a silane coupling agent.

[0060] In an exemplary embodiment, the mass ratio of the first epoxy resin to the microcapsules is 6.3-26.7:1.

[0061] In this embodiment, by controlling the mass ratio of the first epoxy resin to the microcapsules to be 6.3-26.7:1, the epoxy resin cured product can have both good mechanical strength and self-healing effect. Exemplarily, the mass ratio of the first epoxy resin to the microcapsules is 6.3:1, 12.5:1, 18.0:1, and 26.7:1.

[0062] In an exemplary embodiment, the microcapsule includes a first microcapsule particle and a second microcapsule particle, the particle size of the first microcapsule particle is 40-60 μm, and the particle size of the second microcapsule particle is 90-110 μm.

[0063] Microcapsules of different particle sizes have different dissolution rates and permeabilities, which can realize the control of the release rate of the capsule core; in this embodiment, the first microcapsule particles with relatively small particle sizes can have a relatively fast release rate, and the second microcapsule particles with relatively large particle sizes can have a relatively slow release rate. In this way, through the combination of the first microcapsule particles and the second microcapsule particles, a stable and lasting self-repairing effect can be provided; in addition, through the introduction of microcapsule particles of different particle sizes, the elongation at break of the epoxy resin matrix composite material can be significantly improved. Exemplarily, the particle size of the first microcapsule particles can be 40μm, 50μm, and 60μm; the particle size of the second microcapsule particles can be 90μm, 100μm, and 110μm.

[0064] In an exemplary embodiment, the mass ratio of the first microcapsule particles to the second microcapsule particles is 5:1.2-4.8.

[0065] In this embodiment, by controlling the mass ratio of the first microcapsule particles to the second microcapsule particles to be 5:1.2-4.8, the release rate of the microcapsules can be controlled and the efficiency of the microcapsules in repairing cracks can be improved. For example, the mass ratio of the first microcapsule particles to the second microcapsule particles is 5:1.2, 5:2.0, 5:3.0, 5:4.0, 5:4.8.

[0066] In an exemplary embodiment, the first epoxy resin includes one or a combination of bisphenol A epoxy resin and bisphenol F epoxy resin;

[0067] Curing agents include triethylenetetramine;

[0068] The second epoxy resin includes a bisphenol A type epoxy resin.

[0069] In this embodiment, the first epoxy resin can be bisphenol A epoxy resin and / or bisphenol F epoxy resin. Bisphenol A epoxy resin has good processability and adhesion, and its cured product has high strength and certain toughness; bisphenol F epoxy resin has low viscosity, as well as excellent thermal stability and chemical resistance.

[0070] Triethylenetetramine (TETA) is a polyamine curing agent that can be used to cure epoxy resins to form hard coatings or composite materials.

[0071] The second epoxy resin may be bisphenol A epoxy resin, such as E51; bisphenol A epoxy resin has strong cohesive force and adhesive force. Using bisphenol A epoxy resin as the capsule core of the microcapsule can play a good bonding role to improve the crack repair efficiency.

[0072] In an exemplary embodiment, when the first epoxy resin includes bisphenol A epoxy resin and bisphenol F epoxy resin, the mass ratio of bisphenol A epoxy resin to bisphenol F epoxy resin is 1.5-5.5:1.

[0073] In this embodiment, bisphenol A epoxy resin and bisphenol F epoxy resin are compounded, which can not only take advantage of the good processability and adhesion of bisphenol A epoxy resin, but also take advantage of the excellent thermal stability and chemical resistance of bisphenol F epoxy resin, and control the mass ratio of bisphenol A epoxy resin to bisphenol F epoxy resin to 1.5-5.5:1, so that the composite material has better comprehensive performance. Exemplarily, the mass ratio of bisphenol A epoxy resin to bisphenol F epoxy resin is 1.5:1, 2.5:1, 3.0:1, 4.0:1, 5.5:1.

[0074] In an exemplary embodiment, the epoxy resin matrix further includes 0.5-2% of an accelerator.

[0075] In this embodiment, the curing reaction rate can be accelerated by adding an accelerator. For example, the amount of the accelerator can be 0.5%, 1.0%, or 2.0%.

[0076] In an exemplary embodiment, the accelerator includes aniline, triethanolamine, or a combination of both.

[0077] In this embodiment, aniline and triethanolamine are used as amine curing agents to accelerate the reaction between the epoxy resin and the curing agent, thereby shortening the curing time, increasing the curing speed, and also helping to improve the strength and toughness of the epoxy resin cured product.

[0078] An exemplary embodiment of the present application provides a composite material, including carbon fibers and the epoxy resin matrix as described above, and the weight percentages of the components of the composite material are expressed as follows:

[0079] Epoxy resin matrix 30-55 parts by mass;

[0080] 50-70 parts by mass of carbon fiber.

[0081] In this embodiment, carbon fiber is used as a reinforcing material in the composite material, which has the advantages of high specific strength, high rigidity, heat resistance, etc., and can improve the strength and thermal stability of the composite material. Among them, the carbon fiber can be domestic T700 fiber with a linear density of 800g / km.

[0082] For example, in one embodiment, the weight percentage of each component of the composite material is expressed as follows:

[0083] Epoxy resin matrix 30 parts by mass;

[0084] 70 parts by mass of carbon fiber.

[0085] In another embodiment, the weight parts of each component of the composite material are expressed as follows:

[0086] 40 parts by mass of epoxy resin matrix;

[0087] 60 parts by mass of carbon fiber.

[0088] In another embodiment, the weight parts of each component of the composite material are expressed as follows:

[0089] Epoxy resin matrix 55 parts by mass;

[0090] 50 parts by mass of carbon fiber.

[0091] like Figure 1 As shown, an exemplary embodiment of the present application provides a method for preparing a composite material, the method for preparing a composite material is used to prepare the composite material as above, and the preparation method comprises:

[0092] S110, dissolving the epoxy resin matrix in an organic solvent to obtain an epoxy resin matrix solution.

[0093] In step S110, acetone may be used as the organic solvent, and the epoxy resin matrix is ​​dissolved in acetone, stirred at 30°C for 75 minutes, and the epoxy resin matrix solution is obtained after degassing.

[0094] S120, impregnating carbon fiber with epoxy resin matrix solution to obtain an intermediate material.

[0095] In step S120, the intermediate material can be prepared by resin transfer molding (RTM). Resin transfer molding is a process method in which resin is injected into a closed mold to infiltrate a reinforcing material and solidify. This method does not require the preparation of prepregs and the use of autoclaves, and can effectively reduce equipment costs. Exemplarily, the resin transfer molding method is used. After the mold is wiped clean with anhydrous ethanol, a release agent (polyether-modified silicone oil) is used to evenly apply the mold surface; the mold is assembled, carbon fiber (i.e., carbon fiber tow or carbon fiber cloth) is placed in the mold, and an epoxy resin matrix solution is injected into the mold to make the epoxy resin matrix solution infiltrate the carbon fiber to obtain the intermediate material.

[0096] S130, curing the intermediate material under preset conditions to obtain a composite material.

[0097] In step S130, the intermediate material may be cured at room temperature, and after demoulding, a composite material may be obtained.

[0098] The specific implementation methods of the present application are further described below in conjunction with preferred embodiments, and examples of preferred value ranges of each component in the epoxy resin matrix provided in the present application are explained in detail.

[0099] Preferred Example 1

[0100] The percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0101] First epoxy resin 75-90%;

[0102] Curing agent 4-16%;

[0103] Microcapsules 3-12%;

[0104] The capsule wall of the microcapsule includes melamine-urea-formaldehyde resin, and the capsule core of the microcapsule includes a second epoxy resin modified by a silane coupling agent;

[0105] The mass ratio of the first epoxy resin to the microcapsules is 6.3-26.7:1.

[0106] Preferred Example 2

[0107] The percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0108] First epoxy resin 75-90%;

[0109] Curing agent 4-16%;

[0110] Microcapsules 3-12%;

[0111] The capsule wall of the microcapsule includes melamine-urea-formaldehyde resin, and the capsule core of the microcapsule includes a second epoxy resin modified by a silane coupling agent;

[0112] The mass ratio of the first epoxy resin to the microcapsules is 6.3-26.7:1;

[0113] The microcapsule comprises a first microcapsule particle and a second microcapsule particle, the particle size of the first microcapsule particle is 40-60 μm, and the particle size of the second microcapsule particle is 90-110 μm;

[0114] The mass ratio of the first microcapsule particles to the second microcapsule particles is 5:1.2-4.8.

[0115] Preferred Example 3

[0116] The percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0117] First epoxy resin 75-90%;

[0118] Curing agent 4-16%;

[0119] Microcapsules 3-12%;

[0120] The capsule wall of the microcapsule includes melamine-urea-formaldehyde resin, and the capsule core of the microcapsule includes a second epoxy resin modified by a silane coupling agent;

[0121] The mass ratio of the first epoxy resin to the microcapsules is 6.3-26.7:1;

[0122] The microcapsule comprises a first microcapsule particle and a second microcapsule particle, the particle size of the first microcapsule particle is 40-60 μm, and the particle size of the second microcapsule particle is 90-110 μm;

[0123] The mass ratio of the first microcapsule particles to the second microcapsule particles is 5:1.2-4.8;

[0124] The first epoxy resin includes one or a combination of bisphenol A epoxy resin and bisphenol F epoxy resin;

[0125] Curing agents include triethylenetetramine;

[0126] The second epoxy resin includes a bisphenol A type epoxy resin.

[0127] Preferred Example 4

[0128] The percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0129]

[0130] The capsule wall of the microcapsule includes melamine-urea-formaldehyde resin, and the capsule core of the microcapsule includes a second epoxy resin modified by a silane coupling agent;

[0131] The mass ratio of the first epoxy resin to the microcapsules is 6.3-26.7:1;

[0132] The microcapsule comprises a first microcapsule particle and a second microcapsule particle, the particle size of the first microcapsule particle is 40-60 μm, and the particle size of the second microcapsule particle is 90-110 μm;

[0133] The mass ratio of the first microcapsule particles to the second microcapsule particles is 5:1.2-4.8;

[0134] The first epoxy resin includes bisphenol A epoxy resin and bisphenol F epoxy resin, and the mass ratio of bisphenol A epoxy resin to bisphenol F epoxy resin is 1.5-5.5:1;

[0135] Curing agents include triethylenetetramine;

[0136] The accelerator includes one or a combination of aniline and triethanolamine;

[0137] The second epoxy resin includes a bisphenol A type epoxy resin.

[0138] Preferred Example 5

[0139] The percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0140]

[0141] The capsule wall of the microcapsule includes melamine-urea-formaldehyde resin, and the capsule core of the microcapsule includes a second epoxy resin modified by a silane coupling agent;

[0142] The mass ratio of the first epoxy resin to the microcapsules is 10.3-13.9:1;

[0143] The microcapsule comprises a first microcapsule particle and a second microcapsule particle, the particle size of the first microcapsule particle is 40-60 μm, and the particle size of the second microcapsule particle is 90-110 μm;

[0144] The mass ratio of the first microcapsule particles to the second microcapsule particles is 5:2-4;

[0145] The first epoxy resin includes bisphenol A epoxy resin and bisphenol F epoxy resin, and the mass ratio of bisphenol A epoxy resin to bisphenol F epoxy resin is 2-4:1;

[0146] Curing agents include triethylenetetramine;

[0147] The accelerator includes one or a combination of aniline and triethanolamine;

[0148] The second epoxy resin includes a bisphenol A type epoxy resin.

[0149] In order to more clearly explain the technical solution of the present application, the present application lists specific embodiments of the epoxy resin matrix and the composite material, and the beneficial effects of selecting the above-mentioned range of the content of each component will be explained by giving specific experimental data through specific embodiments.

[0150] Example

[0151] It should be noted that the raw materials in the following embodiments can be obtained commercially. Among them, the first epoxy resin uses bisphenol A epoxy resin and bisphenol F epoxy resin. The microcapsule includes a first microcapsule particle with a particle size of 50 μm and a second microcapsule particle with a particle size of 100 μm. The first microcapsule particle and the second microcapsule particle have the same composition, both of which use melamine-urea-formaldehyde resin as the capsule wall and -aminopropyltriethoxysilane modified E51 bisphenol A epoxy resin as the capsule core. The curing agent uses triethylenetetramine; the accelerator uses triethanolamine.

[0152] Embodiment 1: A method for preparing an epoxy resin matrix comprises the following steps:

[0153] (1) Bisphenol A epoxy resin and bisphenol F epoxy resin are mixed in a mass ratio of 5:2 to form a first epoxy resin.

[0154] (2) The first epoxy resin is mixed with a curing agent, microcapsules and an accelerator to obtain an epoxy resin matrix.

[0155] The percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows:

[0156] The first epoxy resin is 83.5%; the curing agent is 9%; the microcapsule is 6%; and the accelerator is 1.5%.

[0157] In order to more clearly explain the technical solution of the present application, the present application also lists Examples 2-12 of the preparation method of the epoxy resin matrix, wherein the formulas of Examples 2-12 are shown in Table 1.

[0158] Table 1 shows a specific embodiment of the epoxy resin matrix in the present application. It should be noted that, except for the parameters listed in Table 1, other parameters of Examples 2-12 are substantially the same as those of Example 1.

[0159] The ratio C1 in Table 1 is the mass ratio of bisphenol A epoxy resin to bisphenol F epoxy resin.

[0160] The ratio C2 is the mass ratio of the first epoxy resin to the microcapsules.

[0161] The ratio C3 is the mass ratio of the first microcapsule particles to the second microcapsule particles.

[0162] Table 1 Formula of epoxy resin matrix of the embodiment (unit: %)

[0163] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 First Epoxy Resin 83.5 83.5 79.5 87.0 75.0 80.0 Curing agent 6.0 7.0 7.0 7.0 11.0 8.0 Microcapsules 9.0 8.0 12.0 4.5 12.0 11.0 Accelerator 1.5 1.5 1.5 1.5 2.0 1.0 Ratio C1 3:1 3:1 3:1 3:1 4:1 1.5:1 Ratio C2 13.9:1 10.4:1 6.6:1 19.3:1 6.3:1 7.3:1 Ratio C3 5:2 5:4 5:3 5:4 5:1.2 5:4.8

[0164] Table 1 (Continued) Formula of epoxy resin matrix of the embodiment (unit: %)

[0165] Example 7 Example 8 Example 9 Example 10 Embodiment 11 Example 12 First Epoxy Resin 80.0 82.0 82.5 85.0 85.0 90.0 Curing agent 16.0 6.0 8.0 5.5 7.5 4.0 Microcapsules 3.0 10.0 8.0 7.5 6.5 5.5 Accelerator 1.0 2.0 1.5 2.0 1.0 0.5 Ratio C1 2:1 5.5:1 2:1 3:1 4:1 3:1 Ratio C2 26.7:1 8.2:1 10.3:1 11.3:1 13.1:1 16.4:1 Ratio C3 5:2 5:3 5:4 5:3 5:2 5:3

[0166] Comparative Example

[0167] Comparative Example 1: The main difference between this comparative example and Example 1 is that no microcapsules are added to the epoxy resin matrix. Specifically, the percentage of the mass of each component in the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​as follows:

[0168] The first epoxy resin is 92%; the curing agent is 7%; and the accelerator is 1.5%.

[0169] Application Examples

[0170] Application Example 1: A method for preparing a composite material, comprising the following steps:

[0171] (1) Dissolving an epoxy resin matrix in acetone to obtain an epoxy resin matrix solution; wherein the epoxy resin matrix is ​​prepared according to Example 1.

[0172] (2) impregnating carbon fiber with an epoxy resin matrix solution to obtain an intermediate material;

[0173] (3) The intermediate material is cured at room temperature to obtain a composite material.

[0174] Among them, in the composite material, the epoxy resin matrix is ​​prepared by Example 1, the amount of the epoxy resin matrix is ​​45 kg, and the amount of the carbon fiber is 53 kg.

[0175] In order to more clearly explain the technical solution of the present application, the present application also lists application examples 2-12 of the preparation method of the composite material, wherein the formula of application example 2-12 is shown in Table 2.

[0176] Table 2 shows a specific example of the composite material in the present application. It should be noted that, except for the parameters listed in Table 2, other parameters of Application Examples 2-12 and Application Example 1 are substantially the same.

[0177] In Table 2, the ratio C4 is the mass ratio of the epoxy resin matrix to the carbon fiber.

[0178] Table 2 Formulation of composite materials for application example

[0179]

[0180] Table 2 (Continued) Formula of composite materials for application example

[0181]

[0182] Comparison Example

[0183] Control Example 1: The difference between the control example and application example 3 is that the epoxy resin matrix is ​​prepared by Control Example 1.

[0184] Performance Testing

[0185] The performance of the composite material prepared in the application example was tested, and the test results are recorded in Table 3.

[0186] Among them, the tensile performance test was carried out in accordance with GB / T3354-2014 "Test method for tensile properties of oriented fiber reinforced polymer matrix composites"; at the same time, 25% tensile strength was used as a load for self-repair performance test, and the repair rate of the composite material was calculated. The repair rate refers to the repair efficiency, that is, when 25% tensile strength is used as a load to destroy the composite material, and then the residual strength after repair for a certain period of time, the ratio of the difference between the original strength and the residual strength to the original strength is used as the repair rate.

[0187] Table 3 Performance test table of application examples and control examples

[0188] Application Example 1 Application Example 2 Application Example 3 Application Example 4 Application Example 5 Application Example 6 Tensile strength, MPa 413 402 389 427 395 440 Elastic modulus, GPa 17.6 16.5 16.8 18.0 17.2 18.8 Elongation at break, % 3.66 3.85 3.21 3.13 3.15 3.11 Repair rate, % 4.21 4.55 4.13 3.78 4.10 3.70

[0189] Table 3 (Continued) Performance test table of application examples and control examples

[0190] Application Example 7 Application Example 8 Application Example 9 Application Example 10 Application Example 11 Application Example 12 Comparative Example 1 Tensile strength, MPa 445 392 398 406 410 418 452 Elastic modulus, GPa 18.6 16.0 16.2 17.0 17.3 17.8 18.2 Elongation at break, % 3.10 3.64 3.87 3.82 3.72 3.33 2.79 Repair rate, % 3.60 4.50 4.56 4.39 4.15 3.94 3.10

[0191] Combining the data in Tables 1 to 3, and combining Application Example 3 with Control Example 1, it can be seen that the repair efficiency and elongation at break of the composite material of Application Example 3 are significantly better than those of Control Example 1, but its tensile strength and elastic modulus are lower than those of Control Example 1, indicating that the addition of microcapsules to the epoxy resin matrix can improve the self-healing effect and elongation at break of the composite material prepared from the epoxy resin matrix, but since the microcapsules cannot participate in the curing of the epoxy resin matrix, the mechanical strength of the composite material will be reduced.

[0192] It can be seen from the data in Tables 1 to 3 that when the amount and proportion of each component in the epoxy resin matrix and the mass ratio of the epoxy resin matrix to the carbon fiber in the composite material change, the mechanical properties, elongation at break and repair efficiency of the composite material will change to a certain extent. Among them, the composite materials of Application Examples 1-2 and Application Examples 9-11 have better comprehensive performance, indicating that the mass percentage of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is: first epoxy resin 82.5-85.0%; curing agent 5.5-8.0%; microcapsule 6.5-9.0%; accelerator 1-2%; the mass ratio of the first epoxy resin to the microcapsule is 10.3-13.9:1; the mass ratio of the first microcapsule particles to the second microcapsule particles is 5:2-4; the mass ratio of bisphenol A epoxy resin to bisphenol F epoxy resin is 2-4:1; when the mass ratio of the epoxy resin matrix to the carbon fiber is 0.85-1:1, a composite material with relatively excellent comprehensive performance can be obtained.

[0193] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0194] 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 above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An epoxy resin matrix, characterized in that The percentage of the mass of each component of the epoxy resin matrix to the total mass of the epoxy resin matrix is ​​expressed as follows: First epoxy resin 75-90%; Curing agent 4-16%; Microcapsules 3-12%; The capsule wall of the microcapsule comprises melamine-urea-formaldehyde resin, and the capsule core of the microcapsule comprises a second epoxy resin modified by a silane coupling agent.

2. The epoxy resin matrix according to claim 1, characterized in that The mass ratio of the first epoxy resin to the microcapsules is 6.3-26.7:

1.

3. The epoxy resin matrix according to claim 1, characterized in that: The microcapsule comprises a first microcapsule particle and a second microcapsule particle, the particle size of the first microcapsule particle is 40-60 μm, and the particle size of the second microcapsule particle is 90-110 μm.

4. The epoxy resin matrix according to claim 3, characterized in that: The mass ratio of the first microcapsule particles to the second microcapsule particles is 5:1.2-4.

8.

5. The epoxy resin matrix according to claim 1, characterized in that: The first epoxy resin includes one or a combination of bisphenol A epoxy resin and bisphenol F epoxy resin; The curing agent includes triethylenetetramine; The second epoxy resin includes bisphenol A type epoxy resin.

6. The epoxy resin matrix according to claim 5, characterized in that: When the first epoxy resin comprises bisphenol A epoxy resin and bisphenol F epoxy resin, the mass ratio of the bisphenol A epoxy resin to the bisphenol F epoxy resin is 1.5-5.5:

1.

7. The epoxy resin matrix according to claim 1, characterized in that: The epoxy resin matrix also includes 0.5-2% of an accelerator.

8. The epoxy resin matrix according to claim 7, characterized in that: The accelerator comprises one or a combination of aniline and triethanolamine.

9. A composite material, characterized in that: The composite material comprises carbon fiber and the epoxy resin matrix according to any one of claims 1 to 8, and the weight parts of the components of the composite material are expressed as follows: Epoxy resin matrix 30-55 parts by mass; 50-70 parts by mass of carbon fiber.

10. A method for preparing a composite material, characterized in that: The method for preparing the composite material is used to prepare the composite material according to claim 9, and the method for preparing the composite material comprises: Dissolving the epoxy resin matrix in an organic solvent to obtain an epoxy resin matrix solution; Infiltrating the carbon fiber with the epoxy resin matrix solution to obtain an intermediate material; The intermediate material is cured under preset conditions to obtain the composite material.

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