A high-strength poly(meth)acrylimide foam and its preparation method and application

Abstract

This application relates to the field of foamed plastic materials, and more specifically to a high-strength poly(meth)acrylimide foamed plastic and its preparation method and applications. The high-strength poly(meth)acrylimide foamed plastic has raw materials including methacrylic acid, acrylonitrile, methacrylonitrile, copolymerization modified resin, additive particles, initiator, crosslinking agent, foaming agent, etc. The foamed plastic finally prepared in this application not only has excellent mechanical strength, balances the contradiction between strength and some other properties, but also can maintain good thermal stability, waterproofness, chemical stability, etc. Thereby, the comprehensive performance of this type of foamed plastic is greatly improved, meeting the performance requirements for foamed plastics in the existing technical field and having broad application potential.

Description

Technical Field

[0001] The present application relates to the field of foamed plastic materials, and more specifically, to a high-strength poly(meth)acrylimide foamed plastic and its preparation method and application. Background Art

[0002] As an advanced engineering material, poly(meth)acrylimide (PMI) foamed plastic has been widely used in many industrial fields due to its excellent mechanical properties, thermal stability and chemical stability. Its applications are particularly prominent in the fields of aerospace, automotive manufacturing and high-performance sports goods, etc. Poly(meth)acrylimide foamed plastic is mainly formed by polymerizing acrylic acid or methacrylic acid monomers to form a prepolymer, and then forming a foam structure under the action of a foaming agent. Its unique molecular structure endows this material with an extremely high strength-to-weight ratio and excellent temperature resistance. And the closed-cell rate of PMI foam is usually higher than 95%, and the performance can be customized by adjusting the monomer ratio, foaming agent type and process parameters. Therefore, it has important application value in the field of lightweight structural materials.

[0003] Thanks to its comprehensive performance advantages, PMI foam has been effectively applied in many fields, including but not limited to being used as a core material for sandwich structures in the aerospace field, such as for aircraft cabin doors, radomes and satellite fairings, replacing traditional aluminum honeycomb structures, achieving a weight reduction of 30-50%; being used in the webs and nacelle covers of wind turbine blades in new energy equipment to improve fatigue resistance and reduce loads; being used as a lightweight filling layer for vehicle floors and interior materials in rail transit; being used in high-end bicycle frames, rowing boats and snowboards in sports equipment, combining light weight and high impact resistance, etc.

[0004] However, although PMI foam has made good progress in the above applications, there are still some bottlenecks in actual applications. For example, the balance between strength and other parts of the performance is poor. Sometimes, in order to achieve other functions, the overall strength of the material is reduced, and the phenomenon of uneven closed-cell wall thickness is likely to occur. Obvious performance drawbacks limit its application in a wider range of fields; the high-temperature stability is limited. Existing modified PMI foams are prone to molecular chain crosslinking in a long-term high-temperature environment, resulting in an increase in the creep deformation rate, which affects its application effect; the comprehensive performance is poor. Existing technologies focus on the improvement of strength and consider less about the comprehensive performance. Summary of the Invention

[0005] Therefore, in order to effectively solve the above-mentioned existing problems, the present application provides a high-strength poly(meth)acrylimide foam and a preparation method thereof. The finally obtained foam of the present application not only has excellent mechanical strength, balances the contradiction between strength and some other properties, but also can maintain good thermal stability, water resistance and chemical stability, etc. Thus, the comprehensive performance of this type of foam is greatly improved, meeting the performance requirements for foams in the existing technical field and having broad application potential.

[0006] The high-strength poly(meth)acrylimide foam, in parts by mass, is composed of the following components: 35-45 parts of methacrylic acid, 20-30 parts of acrylonitrile, 8-15 parts of methacrylonitrile, 15-25 parts of copolymerization modified resin, 5-10 parts of added particles, 1-2 parts of initiator, 1.5-2.5 parts of crosslinking agent, 5-8 parts of foaming agent, 2-3 parts of nucleating agent, 1-1.5 parts of dispersant, and 0.5-1 part of antioxidant.

[0007] As a preferred embodiment, the mass ratio of the methacrylic acid, acrylonitrile and methacrylonitrile is (35-40):(20-25):(10-12).

[0008] As a preferred embodiment, the mass ratio of the methacrylic acid, acrylonitrile and methacrylonitrile is (38-40):(21-23):(10-11).

[0009] As a preferred embodiment, the mass ratio of the methacrylic acid and the copolymerization modified resin is (35-40):(18-22).

[0010] As a preferred embodiment, the copolymerization modified resin is modified polyether ketone.

[0011] As a preferred embodiment, the preparation method of the modified polyether ketone specifically includes the following steps: S1: adding a polyether ketone prepolymer into dimethylacetamide and then adding dodecyl mercaptan; S2: adding N-vinylcarbazole, dodecafluorooctyl methacrylate and isobornyl acrylate and mixing, then adding benzoyl peroxide and trimethylolpropane triacrylate, and stirring; S3: heating and maintaining the temperature in stages for reaction, precipitating the reaction solution, washing and drying to obtain the product.

[0012] As a preferred embodiment, the preparation method of the modified polyether ketone specifically includes the following steps: S1: Add the polyether ketone prepolymer into dimethylacetamide, then add dodecyl mercaptan, and stir at 75-80°C for 2-3 hours until completely uniform; S2: Add N-vinylcarbazole, dodecafluorooctyl methacrylate and isobornyl acrylate, stir at a speed of 100-200 rpm for 20-30 minutes, then add benzoyl peroxide and trimethylolpropane triacrylate, and stir at a speed of 300-400 rpm for 30-40 minutes under nitrogen protection; S3: Raise the temperature to 80-85°C and keep it warm for 2-3 hours, then raise the temperature to 90-95°C and keep it warm for 6-8 hours. After the reaction is completed, pour the reaction solution into deionized water for precipitation, wash it with ethanol 2-3 times, and dry it in vacuum at 80-85°C for 20-24 hours. After completion, it is obtained.

[0013] As a preferred embodiment, the mass ratio of the polyether ketone prepolymer, N-vinylcarbazole, dodecafluorooctyl methacrylate and isobornyl acrylate is (8-9):(1.2-1.5):(1.3-1.5):(0.6-0.8).

[0014] As a preferred embodiment, the mass ratio of the polyether ketone prepolymer, N-vinylcarbazole, dodecafluorooctyl methacrylate and isobornyl acrylate is 9:1.3:1.5:0.7.

[0015] By adding the modified polyether ketone as an important raw material, the mechanical strength, thermal stability, corrosion resistance and other properties of the finally prepared foam plastic are greatly improved. The presence of the main molecular chain of polyether ketone can provide a high-modulus skeleton by relying on its rigid aromatic ring structure, inhibit the deformation of the cell wall, and further enhance the intermolecular interaction force through the π-π conjugation effect of the added carbazole group. The steric hindrance effect of the alicyclic structure improves toughness, inhibits crack propagation, and helps to form dense chemical cross-linking points to evenly disperse stress and avoid stress concentration.

[0016] In a long-term high-temperature use environment, the main-chain ether bond and ketone group are not easily broken at high temperature, and the high thermal stability of the carbazole aromatic ring inhibits the movement of the molecular chain. A better internal cross-linking network controls the molecular chain slip phenomenon in the high-temperature active state. And through the enrichment of fluorine atoms on the surface, a low-surface-energy hydrophobic layer is formed, which blocks the penetration of moisture and corrosive media and inhibits the occurrence of corrosion hydration reaction with higher molecular bond stability.

[0017] As a preferred embodiment, the added particles are a composition of polyphenylene sulfide and silicon carbide nanowires.

[0018] As a preferred embodiment, the mass ratio of the polyphenylene sulfide and the silicon carbide nanowires is (5-6):(1.5-3).

[0019] As a preferred embodiment, the mass ratio of the polyphenylene sulfide to the silicon carbide nanowires is (5 to 5.5):(2 to 2.5).

[0020] As a preferred embodiment, the molecular weight Mw of the polyphenylene sulfide is 30,000 to 60,000 Da.

[0021] As a preferred embodiment, the average diameter of the silicon carbide nanowires is 50 to 70 nm, and the average length is 5 to 10 μm.

[0022] As a preferred embodiment, the initiator is at least one of dicumyl peroxide, tert-butyl perbenzoate, azobisisobutyronitrile, dimethyl azobisisobutyrate, and lauroyl peroxide.

[0023] As a preferred embodiment, the initiator is azobisisobutyronitrile.

[0024] As a preferred embodiment, the crosslinking agent is at least one of pentaerythritol triacrylate, divinylbenzene, bismaleimide, polyethylene glycol dimethacrylate, and triallyl isocyanurate.

[0025] As a preferred embodiment, the crosslinking agent is pentaerythritol triacrylate.

[0026] As a preferred embodiment, the foaming agent is at least one of formamide, azodicarbonamide, sodium bicarbonate, and p-toluenesulfonyl semicarbazide.

[0027] As a preferred embodiment, the foaming agent is formamide or azodicarbonamide.

[0028] As a preferred embodiment, the foaming agent is azodicarbonamide.

[0029] As a preferred embodiment, the nucleating agent is talc.

[0030] As a preferred embodiment, the average particle size of the talc is 3 to 5 μm.

[0031] As a preferred embodiment, the dispersant is BYK-163 or BYK-190.

[0032] As a preferred embodiment, the dispersant is BYK-163.

[0033] As a preferred embodiment, the antioxidant is at least one of antioxidant 1010, antioxidant 168, antioxidant 1076, and antioxidant 1330.

[0034] As a preferred embodiment, the antioxidant is antioxidant 1010 or antioxidant 1076.

[0035] Method for preparing high-strength poly(meth)acrylimide foam, specifically including the following steps: S1: Add methacrylic acid, acrylonitrile, methacrylonitrile and copolymer modification resin into a reaction kettle, stir at 30~42°C for 20~30 min, and then add other remaining raw materials, degas at a vacuum degree of -0.095~-0.090 MPa for 30~40 min; S2: Inject into a mold, pre-polymerize at 35~45°C for 6~10 h, then raise the temperature to 70~90°C, keep the pressure at 4.5~5 MPa for 60~90 min, then release the pressure to normal pressure, cool and demold, and then foam at 180~220°C for 2~5 h. After completion, protect with nitrogen at 165~185°C for 6~8 h, and then cool down step by step to 80°C; S3: After cutting by machine, perform argon plasma cleaning at 100~150 W for 20~22 min. After completion, grind and clean the surface to obtain the product.

[0036] This application further defines the application of the prepared high-strength poly(meth)acrylimide foam in aerospace, new energy equipment, rail transit and sports equipment.

[0037] The beneficial effects of this application are as follows:

[0038] 1. The finally prepared high-strength poly(meth)acrylimide foam of this application not only has excellent mechanical strength, balances the contradiction between strength and some other properties, but also can maintain good thermal stability, water resistance and chemical stability, etc. Thus, the comprehensive performance of this type of foam is greatly improved, meeting the performance requirements of the existing technical field for foam, and having broad application potential.

[0039] 2. The finally prepared high-strength poly(meth)acrylimide foam of this application, through the addition of modified polyether ketone as an important raw material, greatly improves its mechanical strength, thermal stability and corrosion resistance, etc. The presence of the main molecular chain of polyether ketone can provide a high-modulus skeleton relying on its rigid aromatic ring structure, inhibit the deformation of the cell wall, and further enhance the intermolecular interaction force through the π-π conjugation effect of the added carbazole group. The steric hindrance effect of the alicyclic structure improves toughness, inhibits crack propagation, and assists in forming dense chemical cross-linking points to evenly disperse stress and avoid stress concentration.

[0040] 3. The finally obtained high-strength poly(meth)acrylimide foam plastic of this application. Under a long-term high-temperature use environment, the main-chain ether bonds and ketone groups in the copolymer-modified resin are not easily broken at high temperatures, and the molecular chain movement is inhibited by the high thermal stability of the carbazole aromatic ring, so as to better control the molecular chain slip phenomenon in the high-temperature active state. Moreover, through the enrichment of fluorine atoms on the surface, a low-surface-energy hydrophobic layer is formed, which not only blocks the penetration of moisture and corrosive media, but also inhibits the occurrence of corrosion hydration reactions with higher molecular bond stability. Description of the Drawings

[0041] Figure 1 It is an electron micrograph of the internal cell structure of the high-strength poly(meth)acrylimide foam plastic prepared in Example 1 of this application.

[0042] Figure 2 It is a finished product diagram of the high-strength poly(meth)acrylimide foam plastic prepared in Example 1 of this application. Detailed Description of the Invention

[0043] Example 1

[0044] For the high-strength poly(meth)acrylimide foam plastic, calculated by mass, the raw materials are composed of the following components: 38.5 parts of methacrylic acid, 22 parts of acrylonitrile, 10 parts of methacrylonitrile, 20.5 parts of copolymer-modified resin, 6.6 parts of additive particles, 1.5 parts of initiator, 1.8 parts of crosslinking agent, 6.2 parts of foaming agent, 2.2 parts of nucleating agent, 1.3 parts of dispersant, and 0.6 part of antioxidant.

[0045] The copolymer-modified resin is modified polyether ketone. Calculated by mass, its preparation method specifically includes the following steps: S1: Add 9 parts of polyether ketone prepolymer to 30 parts of dimethylacetamide, then add 0.005 part of dodecyl mercaptan, and stir at 80°C for 3 h until completely uniform; S2: Add 1.3 parts of N-vinylcarbazole, 1.5 parts of dodecafluoroheptyl methacrylate, and 0.7 part of isobornyl acrylate, stir at 150 rpm for 25 min, then add 0.12 part of benzoyl peroxide and 0.3 part of trimethylolpropane triacrylate, and stir at 350 rpm for 35 min under nitrogen protection; S3: Raise the temperature to 80°C and keep it warm for 2.5 h, then raise the temperature to 90°C and keep it warm for 7 h. After the reaction is completed, pour the reaction solution into deionized water for precipitation, wash it with ethanol 3 times, and dry it in vacuum at 80°C for 24 h. After completion, it is obtained.

[0046] The polyether ketone prepolymer is purchased from the Victrex 381G model product sold by Victrex Corporation in the UK.

[0047] The additive particles are a composition of polyphenylene sulfide and silicon carbide nanowires, and the mass ratio is 5.3:2.2.

[0048] The molecular weight Mw of polyphenylene sulfide is 45,000 Da, and it is purchased from the product of the 1140T model of Polyplastics Japan sold by Oushuo Plastics Co., Ltd. in Shanghai, China.

[0049] The average diameter of the silicon carbide nanowires is 60 nm, and the average length is 7 μm. They are purchased from the corresponding size products sold by Zhongke Leiming (Beijing) Technology Co., Ltd. in China.

[0050] The initiator is azobisisobutyronitrile; the crosslinking agent is pentaerythritol triacrylate; the foaming agent is azodicarbonamide; the nucleating agent is talcum powder with an average particle size of 3.4 μm.

[0051] The dispersant is BYK-163; the antioxidant is antioxidant 1076.

[0052] A method for preparing high-strength poly(meth)acrylimide foam plastics specifically includes the following steps: S1: Add methacrylic acid, acrylonitrile, methacrylonitrile, and copolymer-modified resin to a reaction kettle, stir at 42 °C for 25 min, and then add other remaining raw materials, degas at a vacuum degree of -0.090 MPa for 40 min; S2: Inject into a mold, pre-polymerize at 45 °C for 8 h, then raise the temperature to 85 °C, keep the pressure at 5 MPa for 80 min, then release the pressure to atmospheric pressure, cool and demold, and then foam at 200 °C for 3 h. After completion, protect with nitrogen at 180 °C for 8 h, and then gradually cool down to 80 °C; S3: After machine cutting, perform argon plasma cleaning at 120 W for 20 min. After completion, grind and clean the surface to obtain the product.

[0053] The internal cell structure of the high-strength poly(meth)acrylimide foam plastics prepared in this application is as Figure 1 shown, and the finished product diagram is as Figure 2 shown.

[0054] Example 2

[0055] This example is only different from Example 1 in the following aspects:

[0056] For the high-strength poly(meth)acrylimide foam plastics, calculated by mass, the raw materials are composed of the following components: 40 parts of methacrylic acid, 20 parts of acrylonitrile, 12 parts of methacrylonitrile, 18.2 parts of copolymer-modified resin, 6.8 parts of added particles, 1.4 parts of initiator, 1.6 parts of crosslinking agent, 5.8 parts of foaming agent, 2.4 parts of nucleating agent, 1.1 parts of dispersant, and 0.6 parts of antioxidant.

[0057] Example 3

[0058] This example is only different from Example 1 in the following aspects:

[0059] High-strength poly(meth)acrylimide foam, by mass, the raw materials are composed of the following components: 35 parts of methacrylic acid, 25 parts of acrylonitrile, 10 parts of methacrylonitrile, 22 parts of copolymer-modified resin, 5.5 parts of added particles, 1.2 parts of initiator, 1.5 parts of crosslinking agent, 5.5 parts of foaming agent, 2.1 parts of nucleating agent, 1.1 parts of dispersant, and 0.5 parts of antioxidant.

[0060] Comparative Example 1

[0061] This comparative example only differs from Example 1 in the following aspects:

[0062] High-strength poly(meth)acrylimide foam, by mass, the raw materials are composed of the following components: 44 parts of methacrylic acid, 28 parts of acrylonitrile, 12 parts of methacrylonitrile, 5.5 parts of copolymer-modified resin, 6.6 parts of added particles, 1.5 parts of initiator, 1.8 parts of crosslinking agent, 6.2 parts of foaming agent, 2.2 parts of nucleating agent, 1.3 parts of dispersant, and 0.6 parts of antioxidant.

[0063] Comparative Example 2

[0064] This comparative example only differs from Example 1 in the following aspects:

[0065] High-strength poly(meth)acrylimide foam, by mass, the raw materials are composed of the following components: 38.5 parts of methacrylic acid, 22 parts of acrylonitrile, 10 parts of methacrylonitrile, 18.5 parts of copolymer-modified resin, 2 parts of added particles, 1.5 parts of initiator, 1.8 parts of crosslinking agent, 6.2 parts of foaming agent, 2.2 parts of nucleating agent, 1.3 parts of dispersant, and 0.6 parts of antioxidant.

[0066] Comparative Example 3

[0067] This comparative example only differs from Example 1 in the following aspects:

[0068] The copolymer-modified resin is modified polyether ketone. By mass, its preparation method specifically includes the following steps: S1: Add 15 parts of polyether ketone prepolymer to 30 parts of dimethylacetamide, then add 0.005 parts of dodecyl mercaptan, and stir at 80 °C for 3 h until completely uniform; S2: Add 1 part of N-vinylcarbazole, 0.5 part of dodecafluoroheptyl methacrylate, and 0.4 part of isobornyl acrylate, stir at 150 rpm for 25 min, then add 0.12 part of benzoyl peroxide and 0.3 part of trimethylolpropane triacrylate, and stir at 350 rpm under nitrogen protection for 35 min; S3: Raise the temperature to 80 °C and keep it warm for 2.5 h, then raise the temperature to 90 °C and keep it warm for 7 h. After the reaction is completed, pour the reaction solution into deionized water for precipitation, wash it with ethanol 3 times, and dry it in vacuum at 80 °C for 24 h to obtain the product.

[0069] Comparative Example 4

[0070] This comparative example is only different from Example 1 in the following aspects:

[0071] The copolymer-modified resin is modified polyether ketone. In terms of parts by mass, its preparation method specifically includes the following steps: S1: Add 6.5 parts of polyether ketone prepolymer to 30 parts of dimethylacetamide, then add 0.005 parts of dodecyl mercaptan, and stir at 80°C for 3 h until completely uniform; S2: Add 2 parts of N-vinylcarbazole, 1.4 parts of dodecafluoroheptyl methacrylate, and 0.1 part of isobornyl acrylate, stir at 150 rpm for 25 min, then add 0.12 parts of benzoyl peroxide and 0.3 parts of trimethylolpropane triacrylate, and stir at 350 rpm for 35 min under nitrogen protection; S3: Raise the temperature to 80°C and keep it warm for 2.5 h, then raise the temperature to 90°C and keep it warm for 7 h. After the reaction is completed, pour the reaction solution into deionized water for precipitation, wash it with ethanol 3 times, and dry it in vacuum at 80°C for 24 h. After completion, it is obtained.

[0072] Comparative Example 5

[0073] This comparative example is only different from Example 1 in the following aspects:

[0074] The added particles are a composition of polyphenylene sulfide and silicon carbide nanowires, and the mass ratio is 6:0.5.

[0075] Comparative Example 6

[0076] This comparative example is only different from Example 1 in the following aspects:

[0077] The added particles are a composition of polyphenylene sulfide and silicon carbide nanowires, and the mass ratio is 1:4.

[0078] Performance Test of the Implementation Case

[0079] 1. Density: The test reference standard is GB / T 6343-2009. The density test results are averaged over 10 tests and recorded in Table 1.

[0080] 2. Mechanical Strength: The test reference standard for compressive strength is GB / T 8813-2020. The samples are treated at a constant temperature and humidity of 23±2°C and 50±3%RH for 24 h. The compression rate is 1 / 10 of the sample thickness / min. The compressive strength of the samples is tested at 23°C and 130°C, and the results are averaged over 10 tests and recorded in Table 1.

[0081] 3. Heat Resistance Stability: The test reference standard is GB / T 20672-2006. At 130°C, a pressure of 1 Mpa is applied to the sample, and the creep deformation rate after 2 h is recorded. The results are averaged over 10 tests and recorded in Table 1.

[0082] 4. Waterproof and moisture absorption resistance: The test reference standard is GB / T 14207-2008. The sample is dried in an oven at (105±2)°C for 2h, then transferred to a desiccator and cooled to room temperature. The specimen is completely immersed in distilled water at (23±0.5)°C and soaked for (24±0.5)h. After that, it is taken out, the surface moisture is blotted dry with filter paper, then immersed in absolute ethanol for about 1min, and then the surface ethanol is blotted dry with filter paper and air-dried for 1min. The water absorption rate is calculated, and the average value of 10 tests is recorded in Table 1.

[0083] 5. Dimensional stability: The test reference standard is GB / T 8811-2008. The sample is treated under constant temperature and humidity at 23±2°C and 50±5% RH for 24h, and the initial dimensions are recorded. The temperature is 130±5°C and the time is 3h. After cooling to room temperature, the final dimensions are measured to obtain the dimensional change rate. The average value of 10 tests is recorded in Table 1.

[0084] Table 1 Performance test results of implementation cases

[0085] Example Compressive strength (23°C, MPa) Compressive strength (130°C, MPa) Dimensional stability (%) Heat-resistant creep deformation rate (%) Waterproof and moisture absorption resistance (%) Density (kg / m³) Example 1 6.51 4.84 0.06 1.31 0.71 112.4 Example 2 6.22 4.86 0.09 1.44 0.69 113.1 Example 3 6.35 4.72 0.07 1.39 0.77 110.3 Comparative example 1 5.06 3.12 0.23 3.14 1.36 98.6 Comparative example 2 5.49 3.39 0.18 2.19 0.94 107.6 Comparative example 3 5.55 3.47 0.16 1.74 0.84 110.1 Comparative example 4 5.43 3.52 0.20 1.92 0.93 111.6 Comparative example 5 5.61 3.44 0.16 1.84 1.04 107.5 Comparative example 6 5.68 3.63 0.17 1.77 1.11 109.4

[0086] From the final performance test results of the examples and comparative examples, Comparative Examples 1-6 obtained worse performance results compared to the examples. The examples, through the better technical solutions defined, through the combined action of the modified resin and other raw materials, provide a high-modulus skeleton, inhibit the deformation of the cell walls, and further enhance the intermolecular interaction force through the π-π conjugation of the added carbazole groups. The steric hindrance effect of the alicyclic structure improves toughness, inhibits crack propagation, and assists in forming dense chemical cross-linking points to evenly disperse stress, avoiding stress concentration. It can also control the molecular chain slip phenomenon in the high-temperature active state with a better cross-linking network. And by enriching fluorine atoms on the surface to form a low-surface-energy hydrophobic layer, while blocking the penetration of moisture and corrosive media, it inhibits the occurrence of corrosion hydration reactions with higher molecular bond stability, thus greatly improving its comprehensive performance.

Claims

1. A high-strength poly(meth)acrylimide foam, characterized in that: The raw materials, by mass parts, include: 35 - 45 parts of methacrylic acid, 20 - 30 parts of acrylonitrile, 8 - 15 parts of methacrylonitrile, 15 - 25 parts of copolymer-modified resin, 5 - 10 parts of added particles, 1 - 2 parts of initiator, and 1.5 - 2.5 parts of crosslinking agent; The copolymer-modified resin is modified polyether ketone, and its preparation method includes: S1: adding polyether ketone prepolymer into dimethylacetamide and then adding dodecyl mercaptan; S2: adding N-vinylcarbazole, dodecafluorooctyl methacrylate and isobornyl acrylate and mixing, then adding benzoyl peroxide and trimethylolpropane triacrylate, and stirring; S3: heating up in stages and holding for reaction, precipitating the reaction solution, washing and drying to obtain; The mass ratio of the polyether ketone prepolymer, N-vinylcarbazole, dodecafluorooctyl methacrylate and isobornyl acrylate is (8 - 9):(1.2 - 1.5):(1.3 - 1.5):(0.6 - 0.8); The added particles are a composition of polyphenylene sulfide and silicon carbide nanowires, and the mass ratio is (5 - 6):(1.5 - 3); The molecular weight Mw of the polyphenylene sulfide is 30000 - 60000 Da; The average diameter of the silicon carbide nanowires is 50 - 70 nm, and the average length is 5 - 10 μm.

2. The high-strength poly(meth)acrylimide foam according to claim 1, wherein: The mass ratio of the methacrylic acid, acrylonitrile and methacrylonitrile is (35 - 40):(20 - 25):(10 - 12).

3. The high-strength poly(meth)acrylimide foam according to claim 2, characterized in that: The mass ratio of the methacrylic acid and the copolymer-modified resin is (35 - 40):(18 - 22).

4. The high-strength poly(meth)acrylimide foam according to claim 3, characterized in that: The mass ratio of the polyphenylene sulfide and the silicon carbide nanowires is (5 - 5.5):(2 - 2.5).

5. The high-strength poly(meth)acrylimide foam according to claim 4, characterized in that: The raw materials also include, by mass parts: 5 - 8 parts of foaming agent, 2 - 3 parts of nucleating agent, 1 - 1.5 parts of dispersant, 0.5 - 1 part of antioxidant; the nucleating agent is talcum powder.

6. The high-strength poly(meth)acrylimide foam according to claim 5, wherein: The initiator is at least one of diisopropyl peroxide, tert-butyl peroxybenzoate, azobisisobutyronitrile, dimethyl azobisisobutyrate and lauroyl peroxide; the crosslinking agent is at least one of pentaerythritol triacrylate, divinylbenzene, bismaleimide, polyethylene glycol dimethacrylate and triallyl isocyanurate.

7. A method for preparing a high-strength poly(meth)acrylimide foam according to any one of claims 1 to 6, characterized in that: Specifically, it includes the following steps: S1: adding methacrylic acid, acrylonitrile, methacrylonitrile and copolymer-modified resin into a reaction kettle, stirring at 30 - 42 °C for 20 - 30 min, and then adding other remaining raw materials, degassing at a vacuum degree of -0.095 - -0.090 MPa for 30 - 40 min; S2: injecting into a mold, pre-polymerizing at 35 - 45 °C for 6 - 10 h, then heating up to 70 - 90 °C, maintaining pressure at 4.5 - 5 MPa for 60 - 90 min, then releasing pressure to atmospheric pressure, cooling and demolding, then foaming at 180 - 220 °C for 2 - 5 h, after completion, protecting with nitrogen at 165 - 185 °C for 6 - 8 h, and then stepwise cooling to 80 °C; S3: cutting with a machine and then cleaning with argon plasma at 100 - 150 W for 20 - 22 min, after completion, grinding and cleaning the surface to obtain.

8. Use of the high-strength poly(meth)acrylimide foam according to any one of claims 1 to 6 in aerospace, new energy equipment, rail transit, and sports equipment.

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