Graphene epoxy resin composite material and preparation method thereof

Abstract

The invention belongs to the technical field of epoxy resin materials. The invention relates to a composite material, in particular to a graphene epoxy resin composite material and a preparation method thereof. The preparation method comprises the following steps: preparing raw materials: taking 100-120 parts by weight of epoxy resin E-51, 70-80 parts by weight of a curing agent, 6-8 parts by weight of an accelerant, 8-10 parts by weight of a silicon dioxide coated graphene filler and 25-30 parts by weight of acetone; pre-dispersion: firstly mixing and dispersing the silicon dioxide coated graphene filler and acetone, then adding epoxy resin E-51, and continuously dispersing uniformly to obtain a pre-dispersion liquid; mixing a curing system: adding a curing agent and an accelerant into the pre-dispersion liquid, performing high-speed shearing and uniform mixing, discharging, heating and curing to obtain the graphene epoxy resin composite material. Wherein the silicon dioxide coated graphene filler comprises a graphene matrix and silicon dioxide coated on the surface of the graphene matrix, and the silicon dioxide and the graphene matrix are combined through Si-C chemical bonds.

Description

Technical Field

[0001] The present invention belongs to the technical field of epoxy resin materials, and more specifically, relates to a graphene epoxy resin composite material and a preparation method thereof. Background Art

[0002] The main purpose of adding graphene to epoxy resin is to significantly improve the overall performance of the composite material through the unique properties of graphene.

[0003] Graphene has extremely high tensile strength (about 130GPa) and modulus (about 1TPa). Its two-dimensional structure can form an efficient stress transfer network in the resin, significantly improving the tensile strength, flexural modulus and impact resistance of epoxy resin while avoiding the increased brittleness that may be caused by traditional fillers (such as glass fiber).

[0004] In addition, graphene has a thermal conductivity of approximately 5000W / (m·K), which can effectively construct a thermal conduction path and solve the problem of poor intrinsic thermal conductivity of epoxy resin. It is suitable for scenarios requiring rapid heat conduction, such as electronic packaging and heat dissipation coatings.

[0005] However, the inventors discovered that adding graphene directly to epoxy resin can easily cause localized microcracks after the epoxy resin cures. In particular, as stress accumulates during use, these cracks can further expand, significantly reducing product performance. Therefore, mitigating these localized microcracks and ensuring consistent product performance during use remains a challenging technical challenge for those skilled in the art. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that when graphene is directly added to an existing epoxy resin system, localized microcracks may occur, resulting in a decrease in product performance. To address this problem, the present invention provides a graphene-epoxy resin composite material and a method for preparing the same.

[0007] The purpose of the present invention is to provide a method for preparing a graphene-epoxy resin composite material.

[0008] Another object of the present invention is to provide a graphene-epoxy resin composite material.

[0009] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0010] A method for preparing a graphene-epoxy resin composite material, the specific preparation steps comprising:

[0011] Raw materials preparation:

[0012] By weight, take 100-120 parts of epoxy resin E-51, 70-80 parts of curing agent, 6-8 parts of accelerator, 8-10 parts of silica-coated graphene filler, and 25-30 parts of acetone;

[0013] Pre-dispersion:

[0014] First, the silica-coated graphene filler was mixed and dispersed with acetone, and then epoxy resin E-51 was added and continued to disperse evenly to obtain a pre-dispersion liquid;

[0015] Curing system mixing:

[0016] Adding a curing agent and an accelerator to the pre-dispersed liquid, mixing uniformly with high-speed shearing, discharging, and heating and curing to obtain a graphene epoxy resin composite material;

[0017] The silica-coated graphene filler includes a graphene matrix and silica coated on the surface of the graphene matrix, and the silica and the graphene matrix are bonded by Si-C chemical bonds.

[0018] The beneficial effects of the above technical solution are:

[0019] During actual research, the inventors discovered that the main reason for the appearance of localized microcracks is that the bonding between the original graphene surface and the epoxy resin is weak, resulting in slippage at the interface during product curing or use. As the interface slip phenomenon gradually worsens during use, cracks gradually propagate along the weak interface, causing the product's performance to deteriorate and affecting normal use.

[0020] Based on the above findings, the above technical solution improves this problem by introducing silica on the surface of graphene and bonding the silica and the graphene matrix with a strong Si-C chemical bond. Specifically: since the bond energy of the Si-C chemical bond is approximately 318 kJ / mol, which is significantly higher than the conventional van der Waals force (approximately 10 kJ / mol), the silica adsorbed on the graphene surface can be used as an anchor point to effectively anchor the interface between graphene and epoxy resin, reducing the occurrence of interfacial slip, and the silanol groups on the silica surface can also react with the epoxy groups of the epoxy resin to further strengthen the interfacial bonding force; in addition, the reason why silica is used as an anchor point is that the modulus of silica is between that of graphene and epoxy resin, which can alleviate the local stress concentration at the interface caused by the sudden change in modulus, thereby leading to local cracking.

[0021] Furthermore, the silica-coated graphene filler is prepared by the following method:

[0022] By weight, take 10-15 parts of graphene matrix, 800-900 parts of 10-15% dilute sulfuric acid, 6-8 parts of 20% hydrogen peroxide, 500-600 parts of 80-85% ethanol solution, and 3-5 parts of ethyl orthosilicate;

[0023] The graphene matrix and dilute sulfuric acid are mixed and dispersed uniformly by ultrasonication, and then hydrogen peroxide is added. The mixture is heated and stirred at 60-65°C and a stirring speed of 200-500 r / min for 45-60 minutes, and then centrifuged and washed until neutral to obtain edge-activated graphene.

[0024] The edge-activated graphene was added to the ethanol solution, stirred evenly, and then cooled to 0°C. Then, ethyl orthosilicate was slowly added dropwise under stirring. After the addition was completed, the pH was adjusted to 9.0-9.2 with ammonia water. Then, the mixture was stirred for 30-40 minutes, centrifuged, washed, and dried to obtain a precursor coating.

[0025] The precursor coating is placed in an inert atmosphere at a temperature of 780-820° C. for a high temperature reaction for 60-80 minutes, then cooled and discharged.

[0026] The beneficial effects of the above technical solution are:

[0027] During further research, the inventors discovered that the silica covering the surface of graphene can act as a physical obstacle, directly hindering the advancement of the crack tip. However, in this process, they accidentally discovered that the anti-crack effect can be further improved by further designing the coating form. Specifically, by designing a relatively high-density silica coating on the edge of graphene, a "hard shell" is formed, while the basal surface achieves a low coverage area of ​​silica, retaining the toughness of the graphene in this area. Therefore, the hard shell effect of the edge can be utilized to force the crack to deflect here during the expansion process, and the retention of the basal surface toughness can induce crack branching and consume energy through a certain degree of plastic deformation.

[0028] Furthermore, the D50 of the graphene matrix is ​​1-5 μm, and the specific surface area of ​​the graphene matrix is ​​1200-1500 m 2 / g;

[0029] The specific surface area is obtained by BET nitrogen adsorption.

[0030] Furthermore, the slowly adding ethyl orthosilicate is: adding ethyl orthosilicate at a dropping rate of 4-6 mL / min.

[0031] Furthermore, the curing agent is selected from any one of methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride.

[0032] Furthermore, the accelerator is selected from any one of 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0033] Furthermore, the high-speed shear mixing includes: high-speed shearing for 10-12 minutes at a shear rate of 3000-3200 r / min.

[0034] Furthermore, the heating and curing comprises:

[0035] Pre-curing at 80-85℃ for 100-120min;

[0036] Then, the main curing is carried out at 120-125℃ for 100-120min;

[0037] Then post-cure at 150-155℃ for 50-60min.

[0038] The beneficial effects of the above technical solution are:

[0039] The inventors have found that further controlling the process during the heating and curing process can also improve the formation and expansion of microcracks. Specifically, if rapid cross-linking and curing are performed, internal stress concentration will occur, and uneven shrinkage will cause microcracks.

[0040] During the above-mentioned curing process, during the pre-curing stage, the resin is initially cross-linked to form a flexible network, which allows the graphene / SiO2 interface to slowly adjust its position, reducing local stress accumulation. In addition, the Si-OH group on the SiO2 surface gradually reacts with the epoxy group, avoiding interfacial debonding caused by intense heat release.

[0041] During the main curing stage, the resin modulus increases and the gradient interface begins to assume the stress transfer function;

[0042] In the post-curing stage, it is fully cured to form a dense network, and the high stability of the interfacial Si-C bond suppresses the post-curing shrinkage stress;

[0043] Ultimately, the shrinkage stress during the curing process is released smoothly along the gradient direction, avoiding the problem of interface peeling.

[0044] A graphene-epoxy resin composite material is prepared by the above-mentioned preparation method. DETAILED DESCRIPTION

[0045] The present invention is further described below with reference to specific examples, which, however, are not intended to limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0046] Unless otherwise specified, the reagents and materials used in the following examples were commercially available.

[0047] Example 1

[0048] Preparation of silica-coated graphene filler:

[0049] By weight, take 10 parts of graphene matrix, 800 parts of 10% dilute sulfuric acid, 6 parts of 20% hydrogen peroxide, 500 parts of 80% ethanol solution, and 3 parts of ethyl orthosilicate;

[0050] The D50 of the graphene matrix is ​​1 μm, and the specific surface area of ​​the graphene matrix is ​​1200 m 2 / g;

[0051] The specific surface area is obtained by BET nitrogen adsorption;

[0052] The graphene matrix and dilute sulfuric acid were mixed and ultrasonically dispersed at an ultrasonic frequency of 80 kHz for 30 minutes, and then hydrogen peroxide was added. The mixture was heated and stirred at 60°C and a stirring speed of 200 r / min for 45 minutes, and then centrifuged to collect the filter cake, which was then washed with deionized water until neutral to obtain edge-activated graphene.

[0053] The edge-activated graphene was added to an ethanol solution, stirred at 300 r / min for 50 min, and then cooled to 0°C. Then, ethyl orthosilicate was slowly added dropwise under stirring. After the addition was completed, the pH was adjusted to 9.0 with ammonia water. Then, the temperature was kept at 0°C and stirred at 200 r / min for 30 min. After the reaction was completed, the solution was centrifuged, the filter cake was collected, washed, and dried to obtain a precursor coating.

[0054] The slow addition comprises: adding ethyl orthosilicate dropwise at a rate of 4 mL / min;

[0055] The precursor coating was heated to 780°C in an inert atmosphere at a rate of 3°C / min, reacted at high temperature for 60 minutes, cooled, and discharged to obtain silica-coated graphene filler;

[0056] The silica-coated graphene filler comprises a graphene matrix and silica coated on the surface of the graphene matrix, wherein the silica and the graphene matrix are bonded by Si-C chemical bonds;

[0057] Raw materials preparation:

[0058] By weight, take 100 parts of epoxy resin E-51, 70 parts of curing agent, 6 parts of accelerator, 8 parts of silica-coated graphene filler, and 25 parts of acetone;

[0059] The curing agent is selected from methyltetrahydrophthalic anhydride;

[0060] The accelerator is selected from 2-ethyl-4-methylimidazole;

[0061] Pre-dispersion:

[0062] First, silica-coated graphene filler was mixed with acetone, and then dispersed under ultrasonic frequency of 80 kHz for 20 minutes. Then, epoxy resin E-51 was added and stirred and dispersed at a speed of 500 r / min for 20 minutes to obtain a pre-dispersion liquid.

[0063] Curing system mixing:

[0064] Add curing agent and accelerator to the pre-dispersion liquid, high-speed shear for 10 minutes at a shear rate of 3000 r / min, discharge the material, pre-cure for 100 minutes at 80°C, then perform main curing at 120°C for 100 minutes, and then post-cure at 150°C for 50 minutes. Cool and obtain a graphene epoxy resin composite material.

[0065] Example 2

[0066] Preparation of silica-coated graphene filler:

[0067] By weight, take 12 parts of graphene matrix, 850 parts of 12% dilute sulfuric acid, 7 parts of 20% hydrogen peroxide, 560 parts of 82% ethanol solution, and 4 parts of ethyl orthosilicate;

[0068] The D50 of the graphene matrix is ​​3 μm, and the specific surface area of ​​the graphene matrix is ​​1400 m 2 / g;

[0069] The specific surface area is obtained by BET nitrogen adsorption;

[0070] The graphene matrix and dilute sulfuric acid were mixed and ultrasonically dispersed at an ultrasonic frequency of 90 kHz for 35 minutes, and then hydrogen peroxide was added. The mixture was heated and stirred at 62°C and a stirring speed of 300 r / min for 50 minutes, and then centrifuged to collect the filter cake, which was then washed with deionized water until neutral to obtain edge-activated graphene.

[0071] The edge-activated graphene was added to an ethanol solution, stirred at 300 r / min for 50 min, and then cooled to 0°C. Then, ethyl orthosilicate was slowly added dropwise under stirring. After the addition was completed, the pH was adjusted to 9.1 with ammonia water. Then, the solution was kept at 0°C and stirred at 200 r / min for 35 min. After the reaction was completed, the solution was centrifuged, the filter cake was collected, washed, and dried to obtain a precursor coating.

[0072] The slow addition is as follows: adding ethyl orthosilicate dropwise at a rate of 5 mL / min;

[0073] The precursor coating was placed in an inert atmosphere and heated to 800°C at a rate of 4°C / min. After high-temperature reaction for 70 minutes, the precursor coating was cooled and discharged to obtain a silica-coated graphene filler.

[0074] The silica-coated graphene filler comprises a graphene matrix and silica coated on the surface of the graphene matrix, wherein the silica and the graphene matrix are bonded by Si-C chemical bonds;

[0075] Raw materials preparation:

[0076] By weight, take 110 parts of epoxy resin E-51, 75 parts of curing agent, 7 parts of accelerator, 9 parts of silica-coated graphene filler, and 28 parts of acetone;

[0077] The curing agent is selected from tetrahydrophthalic anhydride;

[0078] The accelerator is selected from 1-benzyl-2-methylimidazole;

[0079] Pre-dispersion:

[0080] First, silica-coated graphene filler was mixed with acetone, and then dispersed under ultrasonic frequency of 80 kHz for 20 minutes. Then, epoxy resin E-51 was added and stirred and dispersed at a speed of 500 r / min for 20 minutes to obtain a pre-dispersion liquid.

[0081] Curing system mixing:

[0082] Add curing agent and accelerator to the pre-dispersion liquid, and high-speed shear for 11 minutes at a shear rate of 3100 r / min. Discharge the material, pre-curing for 110 minutes at 82°C, followed by main curing for 110 minutes at 122°C, and post-curing for 55 minutes at 153°C. After cooling, a graphene epoxy resin composite material is obtained.

[0083] Example 3

[0084] Preparation of silica-coated graphene filler:

[0085] By weight, take 15 parts of graphene matrix, 900 parts of 15% dilute sulfuric acid, 8 parts of 20% hydrogen peroxide, 600 parts of 85% ethanol solution, and 5 parts of ethyl orthosilicate;

[0086] The D50 of the graphene matrix is ​​5 μm, and the specific surface area of ​​the graphene matrix is ​​1500 m 2 / g;

[0087] The specific surface area is obtained by BET nitrogen adsorption;

[0088] The graphene matrix and dilute sulfuric acid were mixed and ultrasonically dispersed at an ultrasonic frequency of 100 kHz for 40 minutes, and then hydrogen peroxide was added. The mixture was heated and stirred at 65°C and a stirring speed of 500 r / min for 60 minutes, and then centrifuged to collect the filter cake, which was then washed with deionized water until neutral to obtain edge-activated graphene.

[0089] The edge-activated graphene was added to an ethanol solution, stirred at 300 r / min for 50 min, and then cooled to 0°C. Then, ethyl orthosilicate was slowly added dropwise under stirring. After the addition was completed, the pH was adjusted to 9.2 with ammonia water. Then, the solution was kept at 0°C and stirred at 200 r / min for 40 min. After the reaction was completed, the solution was centrifuged, the filter cake was collected, washed, and dried to obtain a precursor coating.

[0090] The slow addition comprises: adding ethyl orthosilicate dropwise at a rate of 6 mL / min;

[0091] The precursor coating was heated to 820°C in an inert atmosphere at a rate of 5°C / min, reacted at high temperature for 80 minutes, cooled, and discharged to obtain silica-coated graphene filler;

[0092] The silica-coated graphene filler comprises a graphene matrix and silica coated on the surface of the graphene matrix, wherein the silica and the graphene matrix are bonded by Si-C chemical bonds;

[0093] Raw materials preparation:

[0094] By weight, take 120 parts of epoxy resin E-51, 80 parts of curing agent, 8 parts of accelerator, 10 parts of silica-coated graphene filler, and 30 parts of acetone;

[0095] The curing agent is selected from hexahydrophthalic anhydride;

[0096] The accelerator is selected from 2-ethyl-4-methylimidazole;

[0097] Pre-dispersion:

[0098] First, silica-coated graphene filler was mixed with acetone, and then dispersed under ultrasonic frequency of 80 kHz for 20 minutes. Then, epoxy resin E-51 was added and stirred and dispersed at a speed of 500 r / min for 20 minutes to obtain a pre-dispersion liquid.

[0099] Curing system mixing:

[0100] Add curing agent and accelerator to the pre-dispersion liquid, and high-speed shear for 12 minutes at a shear rate of 3200 r / min. Discharge the material, pre-cure it at 85°C for 120 minutes, then mainly cure it at 125°C for 120 minutes, and then post-cure it at 155°C for 60 minutes. Cool it to obtain a graphene epoxy resin composite material.

[0101] Example 4

[0102] Compared with Example 1, this embodiment has the following differences:

[0103] The heating curing process is different, specifically:

[0104] Adding a curing agent and an accelerator to the pre-dispersion liquid, high-speed shearing for 10 minutes at a shear rate of 3000 r / min, discharging, curing for 120 minutes at 150° C., and cooling to obtain a graphene epoxy resin composite material;

[0105] The rest of the conditions remain unchanged.

[0106] Example 5

[0107] Compared with Example 1, this embodiment differs in that:

[0108] The preparation methods of silica-coated graphene fillers are different, specifically:

[0109] Preparation of silica-coated graphene filler:

[0110] By weight, take 10 parts of graphene matrix, 800 parts of 90% concentrated sulfuric acid, 20 parts of 20% hydrogen peroxide, 500 parts of 80% ethanol solution, and 3 parts of ethyl orthosilicate;

[0111] The D50 of the graphene matrix is ​​1 μm, and the specific surface area of ​​the graphene matrix is ​​1200 m 2 / g;

[0112] The specific surface area is obtained by BET nitrogen adsorption;

[0113] The graphene matrix and concentrated sulfuric acid were mixed and ultrasonically dispersed at an ultrasonic frequency of 80 kHz for 30 minutes, and then hydrogen peroxide was added. The mixture was heated and stirred at 160°C and a stirring speed of 200 r / min for 45 minutes, and then centrifuged to collect the filter cake, which was then washed with deionized water until neutral to obtain activated graphene.

[0114] The activated graphene was added to the ethanol solution, stirred at 300 r / min for 50 min, and then ethyl orthosilicate was slowly added dropwise under stirring. After the addition was completed, the pH was adjusted to 9.0 with ammonia water. Then, the solution was stirred at 200 r / min at 60°C for 30 min. After the reaction was completed, the solution was centrifuged, the filter cake was collected, washed, and dried to obtain a precursor coating.

[0115] The slow addition comprises: adding ethyl orthosilicate dropwise at a rate of 4 mL / min;

[0116] The precursor coating was heated to 780°C in an inert atmosphere at a rate of 3°C / min, reacted at high temperature for 60 minutes, cooled, and discharged to obtain silica-coated graphene filler;

[0117] The rest of the conditions remain unchanged.

[0118] Since concentrated sulfuric acid is introduced during the oxidation process and the amount of hydrogen peroxide is increased, during the activation process, in addition to the edges being activated, too many oxygen-containing functional groups are also introduced into the basal plane of graphene, so that its basal plane is also covered with too much silica.

[0119] Comparative Example 1

[0120] Compared with Example 1, this comparative example differs in that the surface of the graphene is not coated with silicon dioxide, and the other conditions remain unchanged.

[0121] Comparative Example 2

[0122] Compared with Example 1, this comparative example has the following differences:

[0123] The precursor coating is directly used as a silica-coated graphene filler without undergoing a high-temperature reaction. Therefore, the silica and graphene do not directly form a Si-C chemical bond.

[0124] The performance tests of the products obtained in the above examples and comparative examples were carried out, and the specific test methods and test results are shown below:

[0125] Cylindrical specimens were prepared according to ASTM D695, with specifications of 12.7 mm diameter and 25.4 mm length;

[0126] First test the compressive strength before the vibration test according to the above standards;

[0127] The parallel specimens were then subjected to vibration testing using a sine swept vibration with a frequency range of 50-100 Hz, an acceleration of 3 g, and a test time of 56 h.

[0128] Again, according to the above standards, test the compressive strength of the sample after vibration;

[0129] Thus, the compressive strength retention rate before and after vibration is calculated;

[0130] The above test set up 5 groups of parallel samples and took the average value. The relevant results are shown in Table 1;

[0131] Table 1: Performance test results

[0132] Compressive strength retention rate / % Example 1 92.5 Example 2 93.2 Example 3 94.1 Example 4 90.2 Example 5 90.0 Comparative Example 1 79.9 Comparative Example 2 82.6

[0133] It can be seen from the test results in Table 1 that the product obtained in the embodiment of the present invention, during the vibration test, has its mechanical properties, such as compressive strength, effectively preserved thanks to the hindered expansion of microcracks.

[0134] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a graphene epoxy resin composite material, characterized in that: The specific preparation steps include: Raw materials preparation: By weight, take 100-120 parts of epoxy resin E-51, 70-80 parts of curing agent, 6-8 parts of accelerator, 8-10 parts of silica-coated graphene filler, and 25-30 parts of acetone; Pre-dispersion: First, the silica-coated graphene filler was mixed and dispersed with acetone, and then epoxy resin E-51 was added and continued to disperse evenly to obtain a pre-dispersion liquid; Curing system mixing: Adding a curing agent and an accelerator to the pre-dispersed liquid, mixing uniformly with high-speed shearing, discharging, and heating and curing to obtain a graphene epoxy resin composite material; The silica-coated graphene filler includes a graphene matrix and silica coated on the surface of the graphene matrix, and the silica and the graphene matrix are bonded by Si-C chemical bonds.

2. The method for preparing a graphene epoxy resin composite material according to claim 1, wherein The silica-coated graphene filler is prepared by the following method: By weight, take 10-15 parts of graphene matrix, 800-900 parts of 10-15% dilute sulfuric acid, 6-8 parts of 20% hydrogen peroxide, 500-600 parts of 80-85% ethanol solution, and 3-5 parts of ethyl orthosilicate; The graphene matrix and dilute sulfuric acid are mixed and dispersed uniformly by ultrasonication, and then hydrogen peroxide is added. The mixture is heated and stirred at 60-65°C and a stirring speed of 200-500 r / min for 45-60 minutes, and then centrifuged and washed until neutral to obtain edge-activated graphene. The edge-activated graphene was added to the ethanol solution, stirred evenly, and then cooled to 0°C. Then, ethyl orthosilicate was slowly added dropwise under stirring. After the addition was completed, the pH was adjusted to 9.0-9.2 with ammonia water. Then, the mixture was stirred for 30-40 minutes, centrifuged, washed, and dried to obtain a precursor coating. The precursor coating is placed in an inert atmosphere at a temperature of 780-820° C. for a high temperature reaction for 60-80 minutes, then cooled and discharged.

3. The method for preparing a graphene epoxy resin composite material according to claim 2, wherein: The D50 of the graphene matrix is ​​1-5 μm, and the specific surface area of ​​the graphene matrix is ​​1200-1500 m 2 / g; The specific surface area is obtained by BET nitrogen adsorption.

4. The method for preparing a graphene epoxy resin composite material according to claim 2, wherein: The slowly adding ethyl orthosilicate dropwise is: adding ethyl orthosilicate dropwise at a dropping rate of 4-6 mL / min.

5. The method for preparing a graphene epoxy resin composite material according to claim 1, wherein: The curing agent is selected from any one of methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride and hexahydrophthalic anhydride.

6. The method for preparing a graphene epoxy resin composite material according to claim 1, wherein: The accelerator is selected from any one of 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

7. The method for preparing a graphene epoxy resin composite material according to claim 1, wherein: The high-speed shear mixing includes: high-speed shearing for 10-12 minutes at a shear rate of 3000-3200 r / min.

8. The method for preparing a graphene epoxy resin composite material according to claim 1, wherein: The heating and curing comprises: Pre-curing at 80-85℃ for 100-120min; Then, the main curing is carried out at 120-125℃ for 100-120min; Then post-cure at 150-155℃ for 50-60min.

9. A graphene epoxy resin composite material, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 8.