Net-shaped wave-absorbing foam and preparation method thereof
Through the net molding preparation method and the use of modified carbon nanotubes, the problems of unstable absorption performance and insufficient strength of the wave absorbing foam during the production process are solved, and a more uniform absorption effect and higher strength are achieved.
Patent Information
- Application Number
- CN202411220566.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-02-11
AI Technical Summary
During the production process, existing wave absorbing foams have problems such as unstable wave absorbing performance, complex process, and easy powder loss, making it difficult to take into account both the wave absorbing performance and strength.
By using net molding preparation method, by reacting diisocyanate, polyether diol and polyester diol, small molecule diol chain extender, sealing agent and catalyst, a sealing polyurethane is formed, and with carbon black and silicon carbide The components such as barium titanate and aminosilane modified carbon nanotubes are mixed and foamed to form a uniform absorbent foam.
The net-formed absorbing foam produced has better absorbing effect and strength, and the absorbing filler is evenly distributed, reducing powder loss. The strength and absorbing foam are improved by the use of modified carbon nanotubes. performance.
Abstract
Description
Technical Field
[0001] The present application relates to a microwave absorbing foam, and more specifically, to a net-shaped microwave absorbing foam and a preparation method thereof. Background Art
[0002] Absorbing foam is an absorbing material with foam as the base material. It is mainly used in communication and radar system clutter suppression, anti-electromagnetic interference, microwave darkroom, RCS reduction, aerospace and other fields.
[0003] The existing production process of absorbing foam generally includes the following steps: first preparing PU foam - immersing absorbing powder into PU foam - drying - surface encapsulation. Although the absorbing foam produced by this process can meet the use requirements, its shortcomings are more prominent, mainly manifested in unstable absorbing performance, complex process, and easy powder loss of absorbing powder when precipitated on the PU surface. How to provide an absorbing foam with both absorbing performance and strength has great economic and research value. Summary of the invention
[0004] In order to solve the problem that the absorbing foam has both absorbing performance and strength, the present application provides a net-shaped absorbing foam and a preparation method thereof.
[0005] In the first aspect, the present application provides a net-shaped absorbing foam, comprising the following raw materials in parts by weight: 70-90 parts of polyether diol, 30-40 parts of polyester diol, 2-5 parts of small molecule diol chain extender, 15-25 parts of diisocyanate, 10-20 parts of sealing agent, 0.01-0.1 parts of catalyst, 1-3 parts of dimethylformamide, 5-10 parts of bridging agent, 0.5-1.5 parts of leveling agent, 15-20 parts of carbon black, 5-15 parts of silicon carbide, 5-10 parts of barium titanate, 5-15 parts of carbon nanotubes, 5-10 parts of dispersant, and 5-10 parts of foaming agent.
[0006] By adopting the above scheme, the absorbing foam is prepared by net molding of the foaming agent. Compared with the traditional absorbing foam, the absorbing foam prepared by first preparing the absorbing slurry and then immersing it in the PU foam is more uniform, has a good absorbing effect and a higher strength. By adding a certain mass of polyether diol, polyester diol, small molecule diol chain extender, diisocyanate, sealing agent and catalyst, a closed polyurethane can be formed, which can better control the curing of the absorbing foam, improve the full infiltration and mutual penetration of each component, and the absorbing foam is more uniform, the absorbing filler is more evenly distributed, the absorbing effect is good, and it is less likely to fall off. The micropores of the formed foam are also more uniform, and the strength of the absorbing foam is higher. A certain mass of solvent and additives are added to make the absorbing filler and the polyurethane foam more fully infiltrated, and the foam is more uniform and smooth. By adding a certain amount of carbon black, silicon carbide, barium titanate and carbon nanotubes to absorb waves together, each absorbing component is suitable for acting on the structure of the absorbing foam through scattering and interface polarization.
[0007] In a specific embodiment, the carbon nanotubes are aminosilane-modified carbon nanotubes.
[0008] By adopting the above scheme, the aminosilane-modified carbon nanotubes are dispersed more evenly in the absorbing foam. The silane-modified filler has an organic group and has a better adhesion effect on the foam matrix. The foam noodle matrix polyurethane forms hydrogen bonds with it, and the aminosilane-modified carbon nanotubes also form hydrogen bonds with each other, strengthening the interaction with the foam noodle base material polyurethane, forming a tighter bond after formation, and improving the strength of the absorbing foam.
[0009] In a specific embodiment, the preparation steps of aminosilane-modified carbon nanotubes include: mixing carbon nanotubes with aminosilane coupling agent, then adding ethanol water solution for mixing, heating, stirring, filtering, washing, and drying to obtain aminosilane-modified carbon nanotubes.
[0010] By adopting the above scheme, the preparation steps of aminosilane-modified carbon nanotubes are relatively simple, the carbon nanotubes have a large number of active amino groups on the surface, can be better attached to the foam matrix, are not easy to fall off, can form more hydrogen bonds with polyurethane, have good cross-linking effect, and the obtained absorbing foam has high strength.
[0011] In a specific embodiment, the carbon nanotubes are double-walled carbon nanotubes with a tube diameter of 2-4 nanometers.
[0012] By adopting the above scheme, the carbon nanotubes have a higher specific surface area and better absorbing effect. At the same time, they can be better dispersed in the absorbing foam and are not easy to fall off. The obtained absorbing foam is more stable and has good strength performance.
[0013] In a specific embodiment, the carbon nanotubes are roughened carbon nanotubes.
[0014] By adopting the above scheme, the roughened carbon nanotubes have greater resistance and can be more tightly locked with the matrix of the absorbing foam. The surface of the roughened carbon nanotubes also has more active groups and a higher specific surface area, which can obtain more amino groups, and then work together with the crosslinking of the carbon nanotubes with the matrix and the crosslinking between the carbon nanotubes to further improve the strength of the obtained absorbing foam.
[0015] In a specific embodiment, the preparation steps of roughened carbon nanotubes include: adding sodium sulfate and magnesium fluoride to a hydrogen fluoride aqueous solution in sequence, stirring evenly, adding carbon nanotubes, reacting, filtering, washing, and drying to obtain roughened carbon nanotubes.
[0016] By adopting the above scheme, the preparation steps of the roughened carbon nanotubes are relatively simple, the roughening effect is good, the structure and strength of the carbon nanotubes will not be destroyed, and the obtained absorbing foam has good performance.
[0017] In a specific embodiment, the carbon black specification is 200-325 mesh.
[0018] By adopting the above scheme, the specifications of carbon black are suitable for the internal structure of the absorbing foam of the present application, and can be dispersed more evenly inside the absorbing foam of the present application. After the clutter enters, it can form a more sufficient reflection, and the obtained absorbing foam has good absorbing performance.
[0019] In a specific embodiment, the mass ratio of carbon black to aminosilane coupling agent modified roughened carbon nanotubes is (2-2.1):1.
[0020] By adopting the above scheme, the quality of carbon black and aminosilane modified carbon nanotubes is more suitable, the formed absorbing network has good absorbing effect, and the clutter entering can be fully reflected and absorbed. At the same time, it may be that the filler and the absorbing foam at this ratio achieve a balance between compatibility and the absorbing network, and the absorbing foam obtained at this ratio has excellent absorbing performance and strength.
[0021] In a second aspect, the present application provides a method for preparing a net-shaped absorbing foam, comprising the following steps: S1. reacting diisocyanate, polyether diol and polyester diol at 60-80°C for 1-2h, then adding a small molecule diol chain extender, and then adding a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at high temperature to obtain a net-shaped absorbing foam.
[0022] By adopting the above scheme, the preparation method is relatively simple, and during the heating and curing process, the isocyanate self-polymerizes to further form cross-links, constructing a more uniform and dense network structure, and the obtained absorbing foam has high strength. The foaming effect is good, and the obtained absorbing foam is integrally formed, has a uniform structure, is not easy to fall off, and has high strength.
[0023] In a specific embodiment, high temperature curing is curing at 160-170°C.
[0024] By adopting the above scheme, the curing effect is good, the obtained absorbing foam is relatively flat, has fewer defects, the clutter can be better immersed and absorbed, and the absorbing effect and strength performance of the obtained absorbing foam are good.
[0025] In summary, this application has the following beneficial effects: The present application mixes and foams the absorbing filler and the polyurethane matrix, thereby avoiding the poor bonding of the absorbing foam by first preparing the slurry and then immersing the foam, and the obtained absorbing foam has good strength and absorbing effect.
[0026] The present application modifies carbon nanotubes with aminosilane, limits them to double-walled carbon nanotubes, limits their tube diameters, and further limits their mass ratio with carbon black of a certain specification, so that the obtained absorbing foam has a good internal absorbing network structure and the clutter is better scattered and absorbed. DETAILED DESCRIPTION
[0027] The carbon nanotubes in this application were purchased from Beijing Dekedaojin Technology Co., Ltd. Double-walled carbon nanotubes CNT110, carbon black was purchased from Anguo Chengze Activated Carbon Manufacturing Co., Ltd. 200 mesh carbon black, the blocking agent was methyl ethyl ketone oxime, the catalyst was triethanolamine, the bridging agent was 4,4'-diaminodicyclohexylmethane, and the leveling agent was FLOW and dispersant were purchased from Zhongwan New Materials, and the foaming agent was ASKBA25. The experimental reagents in the preparation examples, embodiments, and comparative examples, unless otherwise specified, were conventional commercial brands or obtained through conventional preparation processes.
[0028] Preparation Example Preparation Example 1: Aminosilane coupling agent modified carbon nanotubes: 30g of silane coupling agent KH-540 and 400ml of 80%wt ethanol aqueous solution were mixed and stirred evenly, and then 120g of carbon nanotubes were added, stirred evenly, reacted, filtered, and dried to obtain aminosilane coupling agent modified carbon nanotubes.
[0029] Preparation Example 2: Roughening of carbon nanotubes: 1 g of sodium sulfate and 1 g of magnesium fluoride are added to 1000 ml of a 25% wt hydrogen fluoride aqueous solution, stirred evenly, and 200 g of carbon nanotubes are added, stirred evenly, filtered after 2 minutes, washed, and dried to obtain roughened carbon nanotubes.
[0030] Preparation Example 3: Aminosilane Coupling Agent Modified Roughened Carbon Nanotubes 1 g of sodium sulfate and 1 g of magnesium fluoride are added to 1000 ml of a 25% wt hydrogen fluoride aqueous solution, stirred evenly, and 200 g of carbon nanotubes are added, stirred evenly, filtered after 2 minutes, washed, and dried to obtain roughened carbon nanotubes.
[0031] 30g of silane coupling agent KH-540 and 400ml of 80%wt ethanol aqueous solution were mixed and stirred evenly, and then 120g of roughened carbon nanotubes were added, stirred evenly, reacted, filtered, and dried to obtain aminosilane coupling agent modified roughened carbon nanotubes.
[0032] Preparation Example 4: Carbon nanotubes modified with epoxy silane coupling agent: 100 g of carbon nanotubes were added to 1200 ml of 80% wt ethanol aqueous solution, stirred evenly, 80 g of epoxy silane coupling agent KH-560 was added, stirred evenly, heated at 90° C., reacted, filtered, washed, and dried to obtain epoxy silane coupling agent modified carbon nanotubes.
[0033] Preparation Example 5: Carbon fiber modified with epoxy silane coupling agent: Add 100g of carbon fiber to 1200ml of 80%wt ethanol aqueous solution, stir evenly, add 80g of epoxysilane coupling agent KH-560, stir evenly, heat at 90°C, react, filter, wash, and dry to obtain epoxysilane coupling agent modified carbon fiber. Example
[0034] Example 1 This embodiment includes the following raw materials in g: 70 g of polyether diol, 30 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 20 g of carbon black, 15 g of silicon carbide, 5 g of barium titanate, 15 g of carbon nanotubes, 10 g of dispersant, and 10 g of foaming agent.
[0035] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0036] Example 2 This embodiment includes the following raw materials in g: 90 g of polyether diol, 40 g of polyester diol, 5 g of ethylene glycol, 25 g of diisocyanate, 10 g of sealing agent, 0.01 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 15 g of carbon black, 5 g of silicon carbide, 10 g of barium titanate, 15 g of carbon nanotubes, 10 g of dispersant, and 10 g of foaming agent.
[0037] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0038] Example 3 This embodiment includes the following raw materials in g: 80 g of polyether diol, 35 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 15 g of carbon black, 15 g of silicon carbide, 10 g of barium titanate, 15 g of carbon nanotubes, 10 g of dispersant, and 10 g of foaming agent.
[0039] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0040] Example 4 This embodiment includes the following raw materials in g: 70 g of polyether diol, 30 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 20 g of carbon black, 15 g of silicon carbide, 5 g of barium titanate, 15 g of aminosilane coupling agent modified carbon nanotubes obtained in Preparation Example 1, 10 g of dispersant, and 10 g of foaming agent.
[0041] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0042] Example 5 This embodiment includes the following raw materials in g: 70 g of polyether diol, 30 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 20 g of carbon black, 15 g of silicon carbide, 5 g of barium titanate, 15 g of roughened carbon nanotubes obtained in Preparation Example 2, 10 g of dispersant, and 10 g of foaming agent.
[0043] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0044] Example 6 This embodiment includes the following raw materials in g: 70 g of polyether diol, 30 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 20 g of carbon black, 15 g of silicon carbide, 5 g of barium titanate, 15 g of aminosilane coupling agent modified roughened carbon nanotubes obtained in Preparation Example 3, 10 g of dispersant, and 10 g of foaming agent.
[0045] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0046] Example 7 This embodiment includes the following raw materials in g: 70g of polyether diol, 30g of polyester diol, 5g of ethylene glycol, 15g of diisocyanate, 20g of sealing agent, 0.1g of catalyst, 1g of dimethylformamide, 5g of bridging agent, 0.5g of leveling agent, 20g of carbon black, 15g of silicon carbide, 5g of barium titanate, 15g of carbon nanotubes modified with epoxy silane coupling agent obtained in Preparation Example 4, 10g of dispersant, and 10g of foaming agent.
[0047] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0048] Example 8 This embodiment includes the following raw materials in g: 70g of polyether diol, 30g of polyester diol, 5g of ethylene glycol, 15g of diisocyanate, 20g of sealing agent, 0.1g of catalyst, 1g of dimethylformamide, 5g of bridging agent, 0.5g of leveling agent, 20g of carbon black, 15g of silicon carbide, 5g of barium titanate, 15g of epoxy silane coupling agent modified carbon fiber obtained in Preparation Example 5, 10g of dispersant, and 10g of foaming agent.
[0049] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0050] Example 9 This embodiment includes the following raw materials in g: 70 g of polyether diol, 30 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 23.3 g of carbon black, 15 g of silicon carbide, 5 g of barium titanate, 11.7 g of aminosilane coupling agent modified roughened carbon nanotubes obtained in Preparation Example 3, 10 g of dispersant, and 10 g of foaming agent.
[0051] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0052] Example 10 This embodiment includes the following raw materials in g: 70 g of polyether diol, 30 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 20 g of carbon black, 15 g of silicon carbide, 5 g of barium titanate, 15 g of carbon nanotubes, 10 g of dispersant, and 10 g of foaming agent.
[0053] The preparation steps of this embodiment are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 170° C. to obtain a net-shaped absorbing foam.
[0054] Comparative Example Comparative Example 1 This comparative example includes the following raw materials in g: 100 g of polyether diol, 30 g of polyester diol, 5 g of ethylene glycol, 15 g of diisocyanate, 20 g of sealing agent, 0.1 g of catalyst, 1 g of dimethylformamide, 5 g of bridging agent, 0.5 g of leveling agent, 10 g of carbon black, 15 g of silicon carbide, 5 g of barium titanate, 15 g of carbon nanotubes, 10 g of dispersant, and 10 g of foaming agent.
[0055] The preparation steps of this comparative example are as follows: S1. reacting diisocyanate, polyether diol and polyester diol at 60°C for 1h, then adding a chain extender, a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at 160° C. to obtain a net-shaped absorbing foam.
[0056] Performance test test 1: detect the minimum reflection loss of the absorbing foam prepared by the embodiment and the comparative example, and the test results are summarized in Table 1; Test 2: detect the tensile strength of the absorbing foam prepared by the embodiment and the comparative example, and the test results are summarized in Table 1.
[0057] Table 1 Minimum reflection loss (dB) Tensile strength(MPa) Example 1 -27.1 35.6 Example 2 -26.8 35.4 Example 3 -27.0 35.6 Example 4 -30.4 37.6 Example 5 -29.8 36.9 Example 6 -33.1 39.8 Example 7 -28.4 37.2 Example 8 -27.5 38.1 Example 9 -36.7 41.3 Example 10 -27.2 35.7 Comparative Example 1 -15.2 -29.7 This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.
Claims
1. A net-shaped absorbing foam, characterized in that: The wave-absorbing foam comprises the following raw materials in parts by weight: 70-90 parts of polyether diol, 30-40 parts of polyester diol, 2-5 parts of small molecule diol chain extender, 15-25 parts of diisocyanate, 10-20 parts of sealing agent, 0.01-0.1 parts of catalyst, 1-3 parts of dimethylformamide, 5-10 parts of bridging agent, 0.5-1.5 parts of leveling agent, 15-20 parts of carbon black, 5-15 parts of silicon carbide, 5-10 parts of barium titanate, 5-15 parts of carbon nanotubes, 5-10 parts of dispersant and 5-10 parts of foaming agent.
2. A net-shaped absorbing foam according to claim 1, characterized in that: The carbon nanotubes are aminosilane-modified carbon nanotubes.
3. A net-shaped absorbing foam according to claim 2, characterized in that: The preparation steps of the aminosilane-modified carbon nanotubes include: mixing carbon nanotubes with an aminosilane coupling agent, then adding an ethanol solution for mixing, heating, stirring evenly, filtering, washing, and drying to obtain the aminosilane-modified carbon nanotubes.
4. A net-shaped absorbing foam according to claim 2, characterized in that: The carbon nanotubes are double-walled carbon nanotubes with a tube diameter of 2-4 nanometers.
5. A net-shaped absorbing foam according to claim 2, characterized in that: The carbon nanotubes are roughened carbon nanotubes.
6. A net-shaped absorbing foam according to claim 4, characterized in that: The preparation steps of the roughened carbon nanotubes include: sequentially adding sodium sulfate and magnesium fluoride to a hydrogen fluoride aqueous solution, stirring evenly, then adding carbon nanotubes, reacting, filtering, washing, and drying to obtain the roughened carbon nanotubes.
7. The net shape absorbing foam according to claim 1, characterized in that: The carbon black specification is 200-325 mesh.
8. The net-shaped absorbing foam according to claim 5, characterized in that: The mass ratio of the carbon black and the aminosilane coupling agent modified roughened carbon nanotubes is (2-2.1):
1.
9. A method for preparing a net-shaped absorbing foam according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1. reacting diisocyanate, polyether diol and polyester diol at 60-80°C for 1-2h, then adding a small molecule diol chain extender, and then adding a blocking agent and a catalyst, reacting, cooling, and obtaining a blocked polyurethane; S2. The closed polyurethane prepared in S1 is mixed evenly with the remaining components, allowed to stand for foaming, and then cured at high temperature to obtain a net-shaped absorbing foam.
10. The method for preparing a net-shaped absorbing foam according to claim 9, characterized in that: The high temperature curing is curing at 160-170°C.