A graphene-based microwave-absorbing honeycomb and preparation method thereof

Abstract

The embodiment of the present invention provides a graphene-based absorbing honeycomb and a preparation method thereof; the preparation method comprises the following steps: a) mixing tubular graphene, alicyclic epoxy resin and an organic solvent, and grinding the mixture to obtain tubular graphene / alicyclic epoxy resin; b) coating the tubular graphene / alicyclic epoxy resin obtained in step a) on the pore walls of the honeycomb core material, and drying the mixture to obtain a graphene-based absorbing honeycomb. Compared with the prior art, the preparation method provided by the present invention adopts the method of coating tubular graphene / alicyclic epoxy resin of a specific component on the pore walls of the honeycomb core material and then drying the mixture to obtain a graphene-based absorbing honeycomb, which has a simple process, low energy consumption and a short production cycle; and the prepared graphene-based absorbing honeycomb has a stable structure, good electrical and thermal conductivity, light weight and high strength, and good absorbing performance, and is suitable for use in radar stealth materials.

Description

Technical Field

[0001] The present invention relates to the technical field of wave-absorbing materials, and more specifically, to a graphene-based wave-absorbing honeycomb and a preparation method thereof. Background Art

[0002] With the rapid development of information technology, various stealth technologies have been widely used in various stealth weapons such as stealth aircraft, stealth missiles, stealth armored vehicles, etc. At present, radar stealth technology is still an important stealth technology for weapons and equipment. The appearance design of weapons and equipment and other stealth technologies are expensive and technically complex, so stealth materials have become the main technology for radar stealth and have received widespread attention. Radar stealth materials refer to a type of material that can absorb radar waves and significantly attenuate the intensity of target echoes. Its main purpose is to reduce the radar scattering cross-sectional area. Radar structural absorbing materials have the dual functions of load-bearing and stealth, and have become an important research field for radar wave stealth materials. As an important component of radar stealth materials, various absorbers have also become the focus of research.

[0003] The absorbing honeycomb is the intermediate core material of radar stealth material or composite absorbing material. The functionality of the absorbing honeycomb has a decisive influence on the wave transmission and absorbing performance of the composite material. The key to the realization of the functionality of the absorbing honeycomb lies in the development of functional resin system, absorbent and its process. The absorbing honeycomb sandwich structure is increasingly favored by the researchers of absorbing materials due to its excellent performance and strong designability. Therefore, domestic and foreign scholars and researchers pay more and more attention to the functional research of absorbing honeycomb, which has also become the research focus and development direction of absorbing materials.

[0004] For example, a Chinese patent with publication number CN110054182A discloses a magnetic graphene-based absorbing honeycomb material and a preparation method thereof. The magnetic graphene-based absorbing honeycomb material provided by the invention is a structural absorbing material formed by uniformly dispersing magnetic graphene oxide in a honeycomb core material. The preparation method comprises the following steps: S1, preparing a magnetic graphene oxide radar wave absorber; S2, stably dispersing the magnetic graphene oxide radar wave absorber in an organic solvent to form an absorbent dispersion; S3, immersing the honeycomb core material in the absorbent dispersion; S4, drying and curing the impregnated honeycomb core material to obtain a magnetic graphene-based absorbing honeycomb material. However, the invention needs to prepare magnetic graphene oxide first. The preparation of magnetic graphene oxide is to use natural graphite flakes as raw materials to obtain graphene oxide by Hummers oxidation method. The obtained graphene oxide is then mixed with ethylene glycol, FeCl3, sodium acetate, and ethylenediamine for hydrothermal reaction, and then vacuum dried to obtain a magnetic graphene oxide absorber; thereafter, a magnetic graphene-based absorbing honeycomb material is prepared. The overall process is complicated, the energy consumption is large, the production cycle is long, and the product performance is poor. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a graphene-based absorbing honeycomb and a preparation method and application thereof. The preparation method provided by the present invention has a simple process, low energy consumption, and a short production cycle. The prepared graphene-based absorbing honeycomb has a stable structure, good electrical and thermal conductivity, light weight and high strength, and good absorbing performance.

[0006] The present invention provides a method for preparing a graphene-based microwave-absorbing honeycomb, comprising the following steps:

[0007] a) mixing the tubular graphene, the alicyclic epoxy resin and the organic solvent, and grinding the mixture to obtain the tubular graphene / alicyclic epoxy resin;

[0008] b) coating the tubular graphene / alicyclic epoxy resin obtained in step a) onto the pore walls of the honeycomb core material, and then drying the resultant to obtain a graphene-based microwave absorbing honeycomb.

[0009] Preferably, the organic solvent is one or more of N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC).

[0010] Preferably, the tubular graphene is single-walled tubular graphene (SWNT) or multi-walled tubular graphene (MWNT).

[0011] Preferably, the alicyclic epoxy resin is selected from one or more of methyl 3,4-epoxycyclohexanecarboxylate, bis((3,4-epoxycyclohexyl)methyl)adipate and diglycidyl 4,5-epoxycyclohexane-1,2-dicarboxylate.

[0012] Preferably, the organic solvent is N,N-dimethylformamide, and the mass ratio of the tubular graphene, alicyclic epoxy resin and N,N-dimethylformamide in step a) is (1-3):40:(57-59).

[0013] Preferably, the grinding process in step a) is carried out at a rotation speed of 500 rpm to 1500 rpm and for a time of 0.5 h to 1 h.

[0014] Preferably, the fineness of the tubular graphene / alicyclic epoxy resin in step a) is less than or equal to 20 μm.

[0015] Preferably, the coating in step b) is performed by flow coating, dip coating or spray coating.

[0016] Preferably, the drying process in step b) is specifically as follows:

[0017] The coated honeycomb core material is placed in a vacuum oven and flipped and deposited with the T direction as the central axis. The rotation speed is 20 rpm to 40 rpm, the temperature is 100° C. to 200° C., and the insulation time is 1 h to 3 h.

[0018] The present invention also provides a graphene-based wave-absorbing honeycomb, which is prepared by the preparation method described in the above technical solution.

[0019] The present invention also provides an application of an absorbing honeycomb in a radar stealth material, wherein the absorbing honeycomb is the graphene-based absorbing honeycomb described in the above technical solution.

[0020] The present invention provides a graphene-based absorbing honeycomb and a preparation method thereof; the preparation method comprises the following steps: a) mixing tubular graphene, alicyclic epoxy resin and an organic solvent, and grinding the mixture to obtain tubular graphene / alicyclic epoxy resin; b) coating the tubular graphene / alicyclic epoxy resin obtained in step a) on the pore walls of a honeycomb core material, and drying the mixture to obtain a graphene-based absorbing honeycomb. Compared with the prior art, the preparation method provided by the present invention adopts the method of coating tubular graphene / alicyclic epoxy resin of a specific component on the pore walls of a honeycomb core material and then drying the mixture to obtain a graphene-based absorbing honeycomb, which has a simple process, low energy consumption and a short production cycle; and the prepared graphene-based absorbing honeycomb has a stable structure, good electrical and thermal conductivity, light weight and high strength, and good absorbing performance, and is suitable for use in radar stealth materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a graphene-based microwave-absorbing honeycomb core material obtained by the preparation method provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention provides a method for preparing a graphene-based microwave-absorbing honeycomb, comprising the following steps:

[0024] a) mixing tubular graphene, alicyclic epoxy resin and N,N-dimethylformamide, and grinding the mixture to obtain tubular graphene / alicyclic epoxy resin;

[0025] b) coating the tubular graphene / alicyclic epoxy resin obtained in step a) onto the pore walls of the honeycomb core material, and then drying the resultant to obtain a graphene-based microwave absorbing honeycomb.

[0026] The present invention first mixes tubular graphene, alicyclic epoxy resin and N-methylformamide N,N-dimethylformamide, and then grinds them to obtain tubular graphene-alicyclic epoxy resin system tubular graphene / alicyclic epoxy resin. In the present invention, the tubular graphene can be selected to use single-walled graphene (SWNT) or multi-walled graphene (MWNT). Among them, the SWNT is selected from the manufacturer: CarbonSolution; model: AP-SWNT (particle size distribution peak: 1.4nm, purity: 60-90%). The MWNT is selected from the manufacturer: Shenzhen Nanoport Co., Ltd., model: S-MWNT-4060 (outer diameter: 40-60nm, length: <2μm, purity: >97%, specific surface area: 60-160m2 / g). Preferably, the tubular graphene is AP-SWNT, which has relatively low cost and narrow particle size distribution. The present invention has no special restriction on the source of the tubular graphene, and commercially available products known to those skilled in the art may be used.

[0027] In the present invention, graphene, as a two-dimensional carbon nanomaterial in a honeycomb lattice, has excellent mechanical and electrical properties, and has important application prospects in various materials. It was once considered to be one of the revolutionary materials of the future. The tubular graphene selected in the present invention has a multi-layer sheet structure that can form a close parallel arrangement in different coating layers, and different surface layers can realize conductive paths or conductive networks. This structure is conducive to improving multiple reflection losses, and the specific morphology of the tubular graphene connects the conductive paths between layers, which is conducive to improving multiple reflection losses in the tubular channel.

[0028] In the present invention, the alicyclic epoxy resin is preferably selected from one or more of methyl 3,4-epoxycyclohexanecarboxylate, bis((3,4-epoxycyclohexyl)methyl)adipate and diglycidyl 4,5-epoxycyclohexane-1,2-dicarboxylate, more preferably bis((3,4-epoxycyclohexyl)methyl)adipate. In a preferred embodiment of the present invention, the alicyclic epoxy resin is bis((3,4-epoxycyclohexyl)methyl)adipate; it has a saturated structure, excellent weather resistance, the finished product will not crack or yellow, and produces carbon dioxide and water during electrical decomposition, unlike aromatic resins that produce graphite to cause short circuits. At the same time, it has a low chlorine content and is particularly suitable for insulating materials with high electrical performance requirements. It has good high-temperature insulation, strong arc resistance and tracking resistance, can be thermally cured or light-cured, has fast curing and low curing shrinkage, and the cured product has a large cross-linking density and excellent flexibility. It has good thermal stability and a Tg higher than 200°C; therefore, the present invention preferably uses bis((3,4-epoxycyclohexyl)methyl)adipate as the alicyclic epoxy resin.

[0029] The present invention has no particular limitation on the source of the alicyclic epoxy resin, and commercially available products of the above-mentioned methyl 3,4-epoxycyclohexanecarboxylate, bis((3,4-epoxycyclohexyl)methyl)adipate and diglycidyl 4,5-epoxycyclohexane-1,2-dicarboxylate, which are well known to those skilled in the art, can be used.

[0030] Meanwhile, the present invention has no particular limitation on the source of the organic solvent, and commercially available products of N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC) well known to those skilled in the art can be used.

[0031] In the present invention, the mass ratio of the tubular graphene, alicyclic epoxy resin and N,N-dimethylformamide is preferably (1-3):40:(57-59), more preferably 1:40:59, 2:40:58 or 3:40:57; on this basis, in the subsequently obtained tubular graphene / alicyclic epoxy resin, the mass ratio of the tubular graphene is 1% to 3%.

[0032] According to the kinetics and thermodynamics of polymer resins, resins exist in three different physical states under different temperature environments: glassy state, highly elastic state (rubbery state) and viscous flow state. The present invention uses the raw materials with the above-mentioned specific content components to form an alicyclic epoxy resin system containing tubular graphene, wherein the alicyclic epoxy resin is prepared by epoxidation of the double bonds of alicyclic olefins. The epoxy groups of the former are directly connected to the alicyclic ring, while the epoxy groups of the latter are connected to the benzene nucleus or aliphatic hydrocarbon by glycidyl ether. The cured product of this system after high-temperature curing has the following characteristics: (1) higher compression and tensile strength; (2) good mechanical properties can be maintained even after long-term exposure to high temperature conditions; (3) good arc resistance, UV aging resistance and weather resistance.

[0033] The present invention has no special limitation on the grinding device, and a horizontal sand mill well known to those skilled in the art is used; the grinding speed is preferably 500 rpm to 1500 rpm, more preferably 1000 rpm; and the grinding time is preferably 0.5 h to 1 h.

[0034] In the present invention, the fineness of the tubular graphene / alicyclic epoxy resin is preferably less than or equal to 20 μm.

[0035] After obtaining the tubular graphene / alicyclic epoxy resin, the present invention applies the obtained tubular graphene / alicyclic epoxy resin to the pore walls of the honeycomb core material and then performs a drying process to obtain a graphene-based microwave absorbing honeycomb.

[0036] In the present invention, the coating method is preferably flow coating, dip coating or spray coating, more preferably flow coating.

[0037] In the present invention, the honeycomb core material is preferably an aramid paper honeycomb core material; the present invention has no special restrictions on this. The aramid paper honeycomb core material selected in the present invention imitates the hexagonal honeycomb structure of a natural honeycomb, and is widely used as a core material for sandwich structures due to its light weight, high strength and high rigidity; when radar waves enter the interior of the sandwich structure from the wave-transmitting surface, the sandwich cavity scatters and absorbs them multiple times, maximally attenuating the radar wave energy and thereby obtaining a broadband and high-intensity wave-absorbing effect.

[0038] In the present invention, the drying process is preferably specifically as follows:

[0039] Place the coated honeycomb core material in a vacuum oven and perform flip deposition with the T direction as the central axis. The rotation speed is 20rpm to 40rpm, the temperature is 100℃ to 200℃, and the insulation time is 1h to 3h.

[0040] More preferably:

[0041] The coated honeycomb core material is placed in a vacuum oven, and the T direction is used as the central axis for flip deposition, the rotation speed is 30rpm, the temperature is 150°C, and the holding time is 2h to obtain a graphene-based absorbing honeycomb core material. In the present invention, the flip deposition can promote the orderly arrangement of tubular graphene on the surface of the substrate; at the same time, the present invention adopts the above-mentioned vacuum curing process, which can strengthen the full combination of the resin system and the honeycomb substrate, reduce the risk of the inner wall absorbing layer falling off, and improve the structural stability of the product.

[0042] The present invention adopts the above-mentioned conveying method (flow coating, dipping coating or spraying method) to coat the mixed resin system containing tubular graphene to the inner wall of the honeycomb core material, and then forms a thin base surface, and then realizes the combination of the tubular graphene and the base surface by flipping deposition, vacuum curing, etc., which not only reduces the complexity of the process, but also realizes the orderly arrangement of the tubular graphene on the surface of the substrate; there are many protrusions on the surface after deposition, most of which are tubular graphene, which can increase the specific surface area of ​​the inner wall and enhance the electrical conductivity and thermal conductivity of the material; in addition, the tubular graphene can play a skeleton support role in the material, avoid the shedding of the inner wall absorbing layer, and enhance the strength of the honeycomb core material; finally, it is deposited on the honeycomb pore wall, and multiple loss mechanisms are introduced, which not only improves the absorbing performance, but also maintains the light weight and high strength characteristics of the honeycomb itself.

[0043] The present invention also provides a graphene-based absorbing honeycomb, which is prepared by the preparation method described in the above technical solution. In the present invention, the honeycomb skeleton structure provides high compressive strength and rigidity by adopting the preparation method described in the above technical solution, and the tubular graphene distributed on the inner wall of the honeycomb hole produces a synergistic effect through multiple electromagnetic wave dissipation mechanisms such as electrical loss, multiple scattering of tubular graphene protrusions and the inner wall of the honeycomb, thereby realizing the structural and functional integration of lightweight composite absorbing materials.

[0044] The present invention also provides an application of an absorbing honeycomb in a radar stealth material, wherein the absorbing honeycomb is a graphene-based absorbing honeycomb as described in the above technical solution. The present invention selects tubular graphene as an absorbent, so that the prepared graphene-based absorbing honeycomb as an absorbing material has the effects of broadband high-efficiency absorption, light weight and high strength, strong environmental adaptability, and simple processing technology; wherein the protruding tubular graphene can increase the specific surface area of ​​the inner wall and enhance the electrical conductivity and thermal conductivity of the material; in addition, the tubular graphene plays a skeleton support role in the material, avoids the shedding of the inner wall absorbing layer, and enhances the strength of the honeycomb core material; finally, it is deposited on the honeycomb hole wall and introduces multiple loss mechanisms, which not only improves the absorbing performance, but also maintains the light weight and high strength characteristics of the honeycomb itself; the honeycomb skeleton structure provides high compressive strength and rigidity, and the tubular graphene distributed on the inner wall of the honeycomb hole produces a synergistic effect through electrical loss, tubular graphene protrusions and multiple scattering of the honeycomb inner wall. Multiple electromagnetic wave dissipation mechanisms produce synergistic effects, thereby realizing the structural and functional integration of lightweight composite absorbing materials, which is suitable for application in radar stealth materials.

[0045] The present invention provides a graphene-based absorbing honeycomb and a preparation method and application thereof; the preparation method comprises the following steps: a) mixing tubular graphene, alicyclic epoxy resin and N,N-dimethylformamide, and grinding to obtain tubular graphene / alicyclic epoxy resin; b) coating the tubular graphene / alicyclic epoxy resin obtained in step a) on the pore wall of the honeycomb core material, and drying to obtain the graphene-based absorbing honeycomb. Compared with the prior art, the preparation method provided by the present invention adopts the method of coating the tubular graphene / alicyclic epoxy resin of a specific component on the pore wall of the honeycomb core material and then drying to obtain the graphene-based absorbing honeycomb, which has a simple process, low energy consumption and a short production cycle; and the prepared graphene-based absorbing honeycomb has a stable structure, good electrical and thermal conductivity, light weight and high strength, and good absorbing performance, and is suitable for application in radar stealth materials.

[0046] In order to further illustrate the present invention, the following examples are used for detailed description. The raw materials used in the following examples of the present invention are all commercially available products; among them, single-walled graphene (SWNT) or multi-walled graphene (MWNT) can be selected for use. Among them, the manufacturer of SWNT is: Carbon Solution; model: AP-SWNT (particle size distribution peak: 1.4nm, purity: 60-90%). The manufacturer of MWNT is: Shenzhen Nanoport Co., Ltd., model: S-MWNT-4060 (outer diameter: 40-60nm, length: <2μm, purity: >97%, specific surface area: 60~160m2 / g). Preferably, the tubular graphene is AP-SWNT, which has relatively low cost and narrow particle size distribution.

[0047] Example 1

[0048] (1) 3 wt% of tubular graphene (model: AP-SWNT), 40 wt% of bis((3,4-epoxycyclohexyl)methyl)adipate, and 57 wt% of N,N-dimethylformamide were mixed evenly, added to a horizontal sand mill, and ground at 1000 rpm for 1.0 h to a fineness of no more than 20 μm to obtain tubular graphene / alicyclic epoxy resin. 3 wt%, 40 wt% and 57 wt% are all mass percentages.

[0049] (2) After coating the tubular graphene / alicyclic epoxy resin obtained in step (1) onto the pore walls of the aramid paper honeycomb by a flow coating method, the honeycomb core material is placed in a vacuum oven and subjected to flip deposition with the T direction as the central axis. The rotation speed is 30 rpm, and the temperature is raised to 150° C. under vacuum pressure. After being kept warm for 2 hours, a graphene-based absorbing honeycomb core material (i.e., the above-mentioned graphene-based absorbing honeycomb) is obtained.

[0050] Example 2

[0051] (1) 2 wt % of tubular graphene (model: AP-SWNT), 40 wt % of bis((3,4-epoxycyclohexyl)methyl)adipate, and 58 wt % of N,N-dimethylformamide were mixed evenly, added into a horizontal sand mill, and ground at 1000 rpm for 1.0 h to a fineness of no more than 20 μm to obtain a tubular graphene / alicyclic epoxy resin.

[0052] (2) After the tubular graphene / alicyclic epoxy resin obtained in step (1) is coated on the pore wall of the aramid paper honeycomb by a flow coating method, the honeycomb core material is placed in a vacuum oven and flipped with the T direction as the central axis for deposition at a rotation speed of 30 rpm. The temperature is raised to 150° C. under vacuum pressure and kept warm for 2 h to obtain a graphene-based absorbing honeycomb core material; see the schematic diagram of the product structure for details. Figure 1 shown.

[0053] Example 3

[0054] (1) 1 wt % of tubular graphene (model: AP-SWNT), 40 wt % of bis((3,4-epoxycyclohexyl)methyl)adipate, and 59 wt % of N,N-dimethylformamide were mixed evenly, added into a horizontal sand mill, and ground at 1000 rpm for 0.5 h to a fineness of no more than 20 μm to obtain a tubular graphene / alicyclic epoxy resin.

[0055] (2) After the tubular graphene / alicyclic epoxy resin obtained in step (1) is coated on the pore wall of the aramid paper honeycomb by a flow coating method, the honeycomb core material is placed in a vacuum oven and flipped and deposited with the T direction as the central axis. The rotation speed is 30 rpm, and the temperature is raised to 150° C. under vacuum pressure. After keeping the temperature for 2 hours, a graphene-based absorbing honeycomb core material is obtained.

[0056] The graphene-based absorbing honeycomb core material obtained by the preparation method provided in Examples 1 to 3 of the present invention was subjected to various performance tests. Among them, the graphene-based absorbing honeycomb core material obtained above was subjected to a reflectivity test by a vector network analyzer. During the test, a 300mm×300mm×5mm metal aluminum plate was used as a standard body, and a bow frame system was used to perform the reflectivity test, specifically:

[0057] The size of the obtained graphene-based absorbing honeycomb material plate (i.e., graphene-based absorbing honeycomb core material) is between 300mm×300mm×10mm and 300mm×300mm×20mm, and the side length of the honeycomb hole is 1.83-2.75mm. A 180mm×180mm×5mm metal aluminum plate is used as the standard body, and a bow frame system is used to test the reflectivity of the prepared honeycomb material.

[0058] The test results of the reflectivity test are shown in Table 1 (wherein the side lengths are all 300 mm×300 mm).

[0059] Table 1 Test results of reflectivity of graphene-based absorbing honeycomb core materials obtained by the preparation methods provided in Examples 1 to 3 of the present invention

[0060]

[0061] As can be seen from Table 1, the reflectivity of the graphene-based absorbing honeycomb core material obtained by the preparation methods provided in Examples 1 to 3 of the present invention is ≤-5.3 dB in the 1-2 GHz band, ≤-8.2 dB in the 2-18 GHz band, and ≤-17.2 dB in the 27-40 GHz band. The test method adopts the GJB 2038 radar absorbing material reflectivity test method.

[0062] It can be seen from the above test method that the graphene-based absorbing honeycomb core material obtained by the preparation method provided in Examples 1 to 3 of the present invention has a stable structure, good electrical and thermal conductivity, and is light and high-strength.

[0063] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a graphene-based microwave-absorbing honeycomb, characterized in that: The following steps are involved: a) mixing tubular graphene, alicyclic epoxy resin and an organic solvent, and grinding the mixture to obtain tubular graphene / alicyclic epoxy resin; b) coating the tubular graphene / alicyclic epoxy resin obtained in step a) onto the pore walls of the honeycomb core material to form a thin base surface, placing the resin in a vacuum oven and performing flip deposition with the T direction as the central axis to arrange the tubular graphene in an orderly manner, thereby obtaining a graphene-based microwave-absorbing honeycomb; wherein, after sedimentation, there are multiple protrusions on the surface, most of which are tubular graphene.

2. The method for preparing the graphene-based microwave-absorbing honeycomb according to claim 1, characterized in that: The organic solvent is one or more of N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC).

3. The method for preparing the graphene-based microwave-absorbing honeycomb according to claim 1, characterized in that: The tubular graphene is single-walled tubular graphene (SWNT) or multi-walled tubular graphene (MWNT).

4. The method for preparing the graphene-based microwave absorbing honeycomb according to claim 1, characterized in that: The alicyclic epoxy resin is selected from one or more of 3,4-epoxycyclohexanecarboxylic acid methyl ester, bis((3,4-epoxycyclohexyl)methyl)adipate and 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester.

5. The method for preparing the graphene-based microwave-absorbing honeycomb according to claim 1, characterized in that: The organic solvent is N,N-dimethylformamide, and the mass ratio of the tubular graphene, alicyclic epoxy resin and N,N-dimethylformamide in step a) is (1-3):40:(57-59).

6. The method for preparing the graphene-based microwave absorbing honeycomb according to claim 1, characterized in that: The rotation speed of the grinding treatment in step a) is 500 rpm to 1500 rpm, and the time is 0.5 h to 1 h.

7. The method for preparing the graphene-based microwave-absorbing honeycomb according to claim 1, characterized in that: The fineness of the tubular graphene / alicyclic epoxy resin in step a) is less than or equal to 20 μm.

8. The method for preparing the graphene-based microwave absorbing honeycomb according to claim 1, characterized in that: The coating method in step b) is flow coating, dip coating or spray coating.

9. The method for preparing the graphene-based microwave absorbing honeycomb according to claim 1, characterized in that: The rotation speed of the flip deposition is 20 rpm to 40 rpm, the temperature is 100° C. to 200° C., and the insulation time is 1 h to 3 h.

10. A graphene-based microwave absorbing honeycomb, characterized in that: The graphene-based microwave-absorbing honeycomb is prepared by the preparation method of any one of claims 1 to 9.

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