High-temperature-resistant fiber-reinforced resin-based composite material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant fiber-reinforced resin-based composite material and a preparation method thereof, and relates to the technical field of composite materials. A novel phthalonitrile-containing benzoxazine monomer structure (BR-Ph) is designed, the molecular structure contains active phenolic hydroxyl groups, ring opening of benzoxazine and polymerization of phthalonitrile can be catalyzed, and the resin curing temperature is effectively reduced. And meanwhile, the BR-Ph is modified. Through modification of epoxy and introduction of 4-APN, while the glass transition temperature is increased, the mechanical properties and thermal properties of the prepared composite laminated board based on the modified benzoxazine resin are improved, and the application requirements of structure-functional resin-based materials can be met. The modification method provided by the invention is simple in process, has an obvious improvement effect on the performance of the benzoxazine resin, has universality and is easy to popularize.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and particularly to a high-temperature resistant fiber-reinforced resin-based composite material and a preparation method thereof. Background Art

[0002] A fiber-reinforced composite laminate refers to a composite material prepared by using a resin as a matrix and a fiber material as a reinforcement through a certain molding and hot pressing process, which has superior significance in many fields such as aerospace, military engineering, automotive industry, and shipbuilding industry. Aramid fiber (AF) is a type of synthetic fiber containing at least 85% amide bonds between two aromatic rings. AF has become a reinforcing material in polymer composites due to its excellent comprehensive properties such as low density, high specific strength, high specific modulus, and high temperature resistance. In aramid fiber-reinforced resin composites, the performance of the resin matrix greatly affects the performance of the composites. Currently, the commonly used matrix resins mainly include types such as epoxy resin and phenolic resin. However, these resin materials are mainly suitable for application scenarios in low-temperature environments. However, with the continuous progress of technologies in high-tech fields, the demand for high-performance materials is increasing day by day, especially the requirements for aspects such as high glass transition temperature, high thermal stability, and excellent mechanical properties are more stringent. Unfortunately, due to their relatively large thermal expansion coefficients and deficiencies in toughness and heat resistance, these resin materials are restricted to a certain extent in their application in a wider range of fields.

[0003] In recent years, phthalonitrile-containing benzoxazine resins have become an ideal type of resin for the resin matrix of composite laminates due to their good heat resistance, dielectric properties, outstanding weather resistance, chemical resistance, etc. However, their disadvantages such as poor mechanical properties, molding process, dielectric properties, and adhesion on fibers still need to be optimized. Therefore, developing novel phthalonitrile-containing benzoxazine monomer structures and further modifying them to develop high-performance resins with excellent comprehensive properties is of great significance for expanding their application in the field of composite laminates.

[0004] Common phthalonitrile-containing benzoxazine resins have disadvantages such as high molding temperature and large brittleness of the cured product, and the large brittleness is the key factor hindering the development and application of aramid fiber composites with it as the resin matrix. Summary of the Invention

[0005] The present invention designs a novel phthalonitrile-containing benzoxazine monomer structure (BR-Ph), which contains active phenolic hydroxyl groups in its molecular structure, can catalyze the ring-opening of benzoxazine and the polymerization of phthalonitrile, and effectively reduces the resin curing temperature. At the same time, BR-Ph is modified.

[0006] To solve the above technical problems, the specific technical solutions of the high-temperature resistant fiber-reinforced resin matrix composite material and its preparation method of the present invention are as follows:

[0007] A preparation method of a high-temperature resistant fiber-reinforced resin matrix composite material, comprising the following steps:

[0008] Step 1: Add a drug, a nitrile group-containing bio-based benzoxazine resin, 4,4'-diaminodiphenylmethane epoxy resin AG80, 4-(4-aminophenoxy)phthalonitrile 4-APN, and a solvent into a reaction vessel. The mass ratio of the drug is 100:x:0.4x, where x = 10, 20, 30. Ultrasonic until the solution is uniform to obtain a glue solution;

[0009] Step 2: Uniformly apply the glue solution prepared in Step 1 on the fiber cloth. Put the fiber cloth soaked with the glue solution into an oven to treat the solvent to obtain a prepreg;

[0010] Step 3: Stack the prepregs and obtain an aramid fiber-reinforced composite material based on the modified benzoxazine resin by using a two-step method of hot pressing and high-temperature post-curing.

[0011] The nitrile group-containing bio-based benzoxazine resin is specifically a phthalonitrile-containing benzoxazine monomer BR-Ph, and its preparation method is as follows:

[0012] Add resveratrol, 4-APN, paraformaldehyde, and a solvent into a reaction vessel; the molar ratio of resveratrol, 4-APN, and paraformaldehyde is 5:1:2.2; heat and stir the reaction mixture to 100°C and keep it for 10 hours, then cool it to room temperature, add a solvent, and at this time the volume of the solvent is 2-5 times the volume of the current reaction mixture. Stir evenly; then pour it into rapidly stirred deionized water and keep stirring for 2 hours, filter to obtain a sample powder, soak and filter it repeatedly with deionized water, and finally dry it at 80°C for 8 hours to obtain a yellow powdery product.

[0013] The solvent includes N,N-dimethylformamide, DMSO, toluene, 1,4-dioxane, N,N-dimethylacetamide, N-methylpyrrolidone, and acetone.

[0014] The solid-liquid ratio of the solvent to the raw material solid is between 10-50%.

[0015] The 4,4'-diaminodiphenylmethane epoxy resin AG80 is replaced with E44 epoxy resin, E51 epoxy resin, or phenolic epoxy resin.

[0016] The fiber cloth is an aramid fiber cloth, a glass fiber cloth, a carbon fiber cloth, or a basalt fiber cloth.

[0017] The specific two-step method of hot pressing and high-temperature post-curing is as follows:

[0018] First, stack the prepregs neatly, sandwich them between two aluminum sheets, and then place them between two iron plates. Put the whole into a hot press. When it is close to the gel state, start hot pressing. The hot pressing procedure is as follows: pressure 5 MPa, 200 °C / 2 h, 240 °C / 1 h, 260 °C / 1 h. After the hot pressing procedure is completed, wait for the temperature of the hot press to drop to room temperature, and then take out the composite laminate.

[0019] Then, place the composite laminate in a high-temperature oven for post-curing treatment. The curing procedure is 280 °C / 2 h, 300 °C / 2 h, 320 °C / 2 h. Wait for the temperature to drop to room temperature to obtain the aramid fiber-reinforced composite material based on the modified benzoxazine resin.

[0020] The present invention also provides a high-temperature resistant fiber-reinforced resin-based composite material, which is prepared by the above method.

[0021] The present invention also provides a high-temperature resistant fiber-reinforced resin-based prepreg, which is prepared by steps 1-2 in the above composite material preparation method.

[0022] The high-temperature resistant fiber-reinforced resin-based composite material and its preparation method of the present invention improve the heat resistance of the existing benzoxazine resin containing phthalonitrile (BR-Ph), enhance the impact strength, and improve the bonding ability with fibers, so as to meet the resin matrix use requirements of high-performance composite laminates.

[0023] Compared with the existing nitrile-based benzoxazine resin, the problems solved by the present invention are as follows:

[0024] 1) The molecular structure design of BR-Ph, the introduction of hydroxyl groups effectively reduces the ring-opening polymerization temperature of benzoxazine and the ring-forming polymerization temperature of cyanide groups.

[0025] 2) Without introducing fillers and bubbles, a benzoxazine resin with high thermal stability performance is prepared by a simple blending modification process.

[0026] 3) Through the modification of epoxy and the introduction of 4-APN, while increasing the glass transition temperature, the mechanical properties and thermal properties of the composite laminate prepared based on the modified benzoxazine resin are improved, and it can meet the application requirements of structure-functional resin-based materials. In summary, the modification method provided by the present invention has a simple process, obvious improvement effect on the performance of benzoxazine resin, has universality, and is easy to promote. Description of the Drawings

[0027] Figure 1 It is the nuclear magnetic spectrum diagram of the monomer BR-Ph prepared by the present invention. Specific Embodiments

[0028] To better understand the purpose, structure and function of the present invention, the following further describes in detail a high-temperature resistant fiber-reinforced resin-based composite material and its preparation method according to the present invention with reference to the accompanying drawings.

[0029] Example 1

[0030] This example provides a simple high-temperature resistant fiber-reinforced resin-based composite material and its preparation method, and the method includes the following steps:

[0031] Step 1: Add a nitrile-containing bio-based benzoxazine resin (BR-Ph), 4,4'-diaminodiphenylmethane epoxy resin (AG80), 4-(4-aminophenoxy)phthalonitrile (4-APN), and the solvent N,N-dimethylformamide (DMF) into a glass reagent bottle. The mass ratio of BR-Ph, AG80, and 4-APN is 100:x:0.4x, where x = 10, 20, 30, and the solid-liquid ratio is 5:5. Ultrasonic until the solution is uniform to obtain a glue solution;

[0032] Step 2: Uniformly apply the glue solution prepared in Step 1 onto a 10 cm * 10 cm aramid fiber cloth, and hang the fiber cloth to drip out the excess glue solution. The mass ratio of the glue solution to the aramid fiber cloth is 40:60;

[0033] Step 3: Repeat the process of Step 2 to obtain 8 aramid fiber cloths soaked with the glue solution.

[0034] Step 4: Put the 8 aramid fiber cloths soaked with the glue solution obtained in Step 3 into an oven, set the temperature to 80 °C, and treat the solvent to obtain 8 prepregs;

[0035] Step 5: Stack the prepregs obtained in Step 4 neatly, sandwich them with two aluminum sheets, and then place them between two iron plates. The whole is put into a hot press, and an aramid fiber-reinforced composite material based on a modified benzoxazine resin is obtained by adopting a two-step method of hot pressing and high-temperature post-curing.

[0036] Further, the nitrile-containing bio-based benzoxazine resin is specifically a phthalonitrile-containing benzoxazine monomer (BR-Ph), and the preparation method is as follows:

[0037] Add 0.05 mol (1.14 g) of resveratrol, 0.01 mol (2.35 g) of 4-APN, 0.022 mol (0.66 g) of paraformaldehyde, and 35 ml of 1,4-dioxane into a 100 mL round-bottom flask. Heat and stir the reaction mixture in an oil bath to 100 °C for 10 hours. Add 40 ml of DMF to the reaction mixture at room temperature, stir well, and then pour it into a large amount of rapidly stirred deionized water. Stir continuously for 2 h, and filter out the sample powder through a Buchner funnel and a water pump. Soak, stir, and filter repeatedly with deionized water, and finally dry at 80 °C for 8 h to obtain a yellow powdery product.

[0038] As Figure 1 shown, the NMR spectrum of the monomer BR-Ph prepared in the present invention shows the molecular structural formula and NMR characterization of the monomer BR-Ph. According to the signals related to the methylene protons in the benzoxazine ring, the number of benzoxazine rings present can be inferred. Generally, in typical benzoxazine compounds, the characteristic 1H NMR signals of O-CH2-N and Ar-CH2-N consist of two singlets with chemical shifts between 3.0 and 5.5 ppm. As Figure 1 shown, the characteristic proton resonances of the O-CH2-N and Ar-CH2-N groups of BR-Ph appear at 5.38 ppm, 5.46 ppm and 4.48 ppm, 4.72 ppm respectively. The integral ratios of these proton groups exactly correspond to two hydrogen atoms in each signal, a total of four hydrogen atoms, thus confirming the previous inference that there are two benzoxazine rings in the BR-Ph structure. At the same time, there is obviously an active hydroxyl hydrogen with a chemical shift of 9.59 ppm. In addition, all the hydrogens on the aromatic ring and the hydrogens on the olefin can be well assigned in terms of position and ratio. This indicates that two hydroxyl groups of resveratrol are consumed during the synthesis, leaving one hydroxyl group. Finally, the structural formula of BR-Ph is determined.

[0039] Example 2

[0040] Step 1: Add 30 g of BR-Ph and 30 g of N,N-dimethylformamide with a solid-liquid ratio of 5:5 into a glass reagent bottle, and ultrasonically dissolve it into a uniform colloidal solution.

[0041] Step 2: Take 43 g of the colloidal solution prepared in Step 1 and 32 g of 8 aramid fiber cloths, with a mass ratio of the colloidal solution to the aramid fiber cloth of 40:60. Brush the colloidal solution evenly on a 10 cm * 10 cm aramid fiber cloth, and hang the fiber cloth to drip out the excess colloidal solution.

[0042] Step 3: Repeat the process of Step 2 to obtain 8 aramid fiber cloths saturated with the colloidal solution.

[0043] Step 4: Put the 8 aramid fiber cloths soaked with the sizing agent obtained in Step 3 into an oven, set the temperature at 80 °C, treat the solvent, and obtain 8 prepregs.

[0044] Step 5: Stack the prepregs obtained in Step 4 neatly, sandwich them with two aluminum sheets in the middle, and then place them between two iron plates. Put the whole into a hot press. When approaching gelation, start hot pressing. The hot pressing program is as follows: pressure 5 MPa, 200 °C / 2 h, 240 °C / 1 h, 260 °C / 1 h. After the hot pressing program is completed, wait for the temperature of the hot press to drop to room temperature, and take out the composite laminate.

[0045] Step 6: Place the composite laminate obtained in Step 5 in a high-temperature oven for post-curing treatment. The curing program is 280 °C / 2 h, 300 °C / 2 h, 320 °C / 2 h. Wait for the temperature to drop to room temperature to obtain the aramid fiber reinforced composite material based on the modified benzoxazine resin.

[0046] The benzoxazine product is made through the above steps. The flexural strength of the laminate based on the modified benzoxazine resin is 249.87 MPa, the flexural modulus is 7.75 GPa, the impact strength is 63.5 KJ / m 2 , and the interlaminar shear strength is 22.14 MPa. The thermal decomposition temperature (T 5％ ) is 497.91 °C, and the glass transition temperature (T g ) obtained by thermomechanical analysis (TMA) test is 353 °C.

[0047] Example 3

[0048] Step 1: Put 30 g of BR-Ph, 3 g of 4,4'-diaminodiphenylmethane epoxy resin (AG80), 1.2 g of 4-(4-aminophenoxy)phthalonitrile (4-APN), and 34.2 g of N,N-dimethylformamide, with a solid-liquid ratio of 5:5. Add them to a glass reagent bottle. Ultrasonically dissolve to obtain a uniform sizing agent.

[0049] Step 2: Take 43 g of the sizing agent prepared in Step 1 and 32 g of 8 aramid fiber cloths, with a mass ratio of sizing agent to aramid fiber cloth of 40:60. Uniformly brush the sizing agent on the aramid fiber cloth of 10 cm * 10 cm, and hang the fiber cloth to drip out the excess sizing agent.

[0050] Step 3: Repeat the process of Step 2 to obtain 8 aramid fiber cloths soaked with the sizing agent.

[0051] Step 4: Put the 8 aramid fiber cloths soaked with the sizing agent obtained in Step 3 into an oven, set the temperature at 80 °C, treat the solvent, and obtain 8 prepregs.

[0052] Step 5: Stack the prepregs obtained in Step 4 neatly, sandwich them between two aluminum sheets, and then place them between two iron plates. Put the whole into a hot press. When approaching gelation, start hot pressing. The hot pressing procedure is as follows: pressure 5 MPa, 200 °C / 2 h, 240 °C / 1 h, 260 °C / 1 h. After the hot pressing procedure is completed, wait for the temperature of the hot press to drop to room temperature, and then take out the composite laminate.

[0053] Step 6: Place the composite laminate obtained in Step 5 in a high-temperature oven for post-curing treatment. The curing procedure is 280 °C / 2 h, 300 °C / 2 h, 320 °C / 2 h. Wait for the temperature to drop to room temperature to obtain the aramid fiber-reinforced composite material based on the modified benzoxazine resin.

[0054] The benzoxazine product is made through the above steps. The flexural strength of the laminate based on the modified benzoxazine resin is 271.06 MPa, the flexural modulus is 8.69 GPa, the impact strength is 67.96 KJ / m 2 , and the interlaminar shear strength is 23.49 MPa. The thermal decomposition temperature (T 5％ ) is 495.45 °C, and the glass transition temperature (T g ) is 424.1 °C.

[0055] Example 4

[0056] Step 1: Put 30 g of BR-Ph, 6 g of 4,4'-diaminodiphenylmethane epoxy resin (AG80), 2.4 g of 4-(4-aminophenoxy)phthalonitrile (4-APN), and 38.4 g of N,N-dimethylformamide. The solid-liquid ratio is 5:5; add them to a glass reagent bottle and ultrasonically dissolve to form a uniform glue solution.

[0057] Step 2: Take 43 g of the glue solution prepared in Step 1 and 32 g of 8 aramid fiber cloths. The mass ratio of the glue solution to the aramid fiber cloths is 40:60. Brush the glue solution evenly on the aramid fiber cloths of 10 cm * 10 cm, and hang the fiber cloths to drip out the excess glue solution.

[0058] Step 3: Repeat the process of Step 2 to obtain 8 aramid fiber cloths saturated with the glue solution.

[0059] Step 4: Put the 8 aramid fiber cloths saturated with the glue solution obtained in Step 3 into an oven, set the temperature to 80 °C, and treat the solvent to obtain 8 prepregs.

[0060] Step 5: Stack the prepregs obtained in Step 4 neatly, sandwich them between two aluminum sheets, and then place them between two iron plates. Put the whole into a hot press. When approaching gelation, start hot pressing. The hot pressing program is: pressure 5 MPa, 200 °C / 2 h, 240 °C / 1 h, 260 °C / 1 h. After the hot pressing program is completed, wait for the temperature of the hot press to drop to room temperature, and then take out the composite laminate.

[0061] Step 6: Place the composite laminate obtained in Step 5 in a high-temperature oven for post-curing treatment. The curing program is 280 °C / 2 h, 300 °C / 2 h, 320 °C / 2 h. Wait for the temperature to drop to room temperature to obtain an aramid fiber reinforced composite based on the modified benzoxazine resin.

[0062] The benzoxazine product is made through the above steps. The flexural strength of the laminate based on the modified benzoxazine resin is 277.37 MPa, the flexural modulus is 9.52 GPa, the impact strength is 74.22 KJ / m 2 , and the interlaminar shear strength is 24.57 MPa. The thermal decomposition temperature (T 5％ ) is 494.83 °C, and the glass transition temperature (T g ) is 417.9 °C.

[0063] Example 5

[0064] Step 1: Take 30 g of BR-Ph, 9 g of 4,4'-diaminodiphenylmethane epoxy resin (AG80), 3.6 g of 4-(4-aminophenoxy)phthalonitrile (4-APN), and 42.6 g of N,N-dimethylformamide. The solid-liquid ratio is 5:5. Add them into a glass reagent bottle. Ultrasonically dissolve to obtain a uniform glue solution.

[0065] Step 2: Take 43 g of the glue solution prepared in Step 1 and 32 g of 8 aramid fiber cloths. The mass ratio of the glue solution to the aramid fiber cloths is 40:60. Brush the glue solution evenly on the aramid fiber cloths of 10 cm * 10 cm, and hang the fiber cloths to drip out the excess glue solution.

[0066] Step 3: Repeat the process of Step 2 to obtain 8 aramid fiber cloths saturated with the glue solution.

[0067] Step 4: Put the 8 aramid fiber cloths saturated with the glue solution obtained in Step 3 into an oven, set the temperature to 80 °C, and treat the solvent to obtain 8 prepregs.

[0068] Step 5: Stack the prepregs obtained in Step 4 neatly, sandwich them between two aluminum sheets, and then place them between two iron plates. Put the whole into a hot press. When approaching gelation, start hot pressing. The hot pressing program is as follows: pressure 5 MPa, 200 °C / 2 h, 240 °C / 1 h, 260 °C / 1 h. After the hot pressing program is completed, wait for the temperature of the hot press to drop to room temperature, and then take out the composite laminate.

[0069] Step 6: Place the composite laminate obtained in Step 5 in a high-temperature oven for post-curing treatment. The curing program is 280 °C / 2 h, 300 °C / 2 h, 320 °C / 2 h. Wait for the temperature to drop to room temperature to obtain the aramid fiber-reinforced composite based on the modified benzoxazine resin.

[0070] The benzoxazine product is prepared through the above steps. The flexural strength of the laminate based on the modified benzoxazine resin is 303.62 MPa, the flexural modulus is 10.27 GPa, the impact strength is 84.87 KJ / m 2 , and the interlaminar shear strength is 25.19 MPa. The thermal decomposition temperature (T 5％ ) is 477.95 °C, and the glass transition temperature (T g ) is 411.9 °C.

[0071] Through the laminates based on the modified benzoxazine resin prepared in Examples 2 - 5, it can be seen from the measured physical properties that with the addition of AG80 epoxy resin and 4-APN, the resin matrix prepared in Examples 3 - 5 shows more excellent high-temperature resistance, high thermal stability, high mechanical strength and modulus, etc. compared with Example 2. Through the laminates based on the modified benzoxazine resin prepared in Examples 2 - 5, it can be seen from the measured physical properties that with the addition of AG80 epoxy resin and 4-APN, while improving the toughness and glass transition temperature of the laminate of the modified benzoxazine resin, the high heat resistance is also maintained. The flexural modulus is increased by 32.52%, the flexural strength is increased by 21.51%, the impact strength is increased by 33.65%, the interlaminar shear strength is increased by 13.78%, T5% remains at 95.99% before modification, and the glass transition temperature is increased by 58.9 °C. Thus, it can be seen that the modified resin matrix prepared in Examples 3 - 5 shows more excellent high-temperature resistance, high thermal stability, high mechanical strength and modulus, etc. compared with Example 2.

[0072] The introduction of 4-APN can not only act as a curing agent but also increase the degree of cross-linking reaction. The amino group in 4-APN can catalyze the ring-opening polymerization of epoxy and benzoxazine and the ring-forming polymerization of cyanide group; the cyanide group in 4-APN can participate in the ring-forming polymerization of the cyanide group in BR-Ph.

[0073] The hydroxyl groups generated after the epoxy rings in AG80 epoxy resin are ring-opened can promote the ring-opening polymerization of benzoxazine rings and the ring-forming polymerization of cyanide groups, and can also react with benzoxazine resin, thereby improving the heat resistance of the resin matrix.

[0074] The hydroxyl and cyanide groups in the ring-opened epoxy rings and oxazine rings in the resin matrix, as polar groups, can effectively improve the adhesion ability between the resin matrix and the fibers.

[0075] The flexible chain segments of epoxy resin can improve the brittleness of the resin matrix. Introducing the flexible chain segments of epoxy resin into BR-Ph resin can significantly improve the impact strength of the resin.

[0076] It can be understood that the present invention is described through some embodiments. Those skilled in the art know that, without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. Additionally, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A method for preparing a high temperature resistant fiber reinforced resin-based composite material, characterized in that: The following steps are involved: Step 1: Add the nitrile-containing bio-based benzoxazine resin, 4,4'-diaminodiphenylmethane epoxy resin AG80, 4-(4-aminophenoxy)phthalonitrile 4-APN, and solvent into a reaction container, with the drug mass ratio being 100:x:0.4x, x=10, 20, 30, and ultrasonicate until the solution is uniform to obtain a glue solution; Step 2: Evenly apply the glue prepared in step 1 on the fiber cloth, put the fiber cloth soaked with the glue into an oven, treat the solvent, and obtain a prepreg; Step 3: stack the prepregs and obtain an aramid fiber reinforced composite material based on the modified benzoxazine resin by a two-step method of hot pressing molding and high-temperature post-curing.

2. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 1, characterized in that: The nitrile-containing bio-based benzoxazine resin is specifically a benzoxazine monomer BR-Ph containing phthalonitrile, and the preparation method thereof is as follows: Resveratrol, 4-APN, paraformaldehyde and solvent were added to the reaction vessel; the molar ratio of resveratrol, 4-APN and paraformaldehyde was 5:1:2.2; the reaction mixture was heated and stirred to 100°C for 10 hours, then cooled to room temperature, the solvent was added and stirred evenly; then poured into rapidly stirred deionized water and stirred for 2 hours, filtered to obtain sample powder, repeatedly soaked and filtered in deionized water, and finally dried at 80°C for 8 hours to obtain a yellow powder product.

3. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 2, characterized in that: The solvent includes N,N-dimethylformamide, DMSO, toluene, 1,4-dioxane, N,N-dimethylacetamide, N-methylpyrrolidone, and acetone.

4. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 3, characterized in that: The solid-liquid ratio of the solvent to the raw material solid is between 10-50%.

5. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 4, characterized in that: The 4,4'-diaminodiphenylmethane epoxy resin AG80 is replaced by E44 epoxy resin, E51 epoxy resin or phenolic epoxy resin.

6. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 5, characterized in that: The fiber cloth is aramid fiber cloth, glass fiber cloth, carbon fiber cloth or basalt fiber cloth.

7. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 6, characterized in that: The two-step method of hot pressing and high temperature post-curing is as follows: First, the prepregs are neatly stacked together, sandwiched between two aluminum sheets, and then placed between two iron plates, and the whole is placed in a hot press. When it is close to a gel state, hot pressing begins. The hot pressing procedure is: pressure 5MPa, 200℃ / 2h, 240℃ / 1h, 260℃ / 1h. After the hot pressing procedure is completed, wait for the temperature of the hot press to drop to room temperature and take out the composite laminate. The composite laminate is then placed in a high-temperature oven for post-curing treatment at a curing procedure of 280°C / 2h, 300°C / 2h, and 320°C / 2h; when the temperature drops to room temperature, an aramid fiber reinforced composite material based on a modified benzoxazine resin is obtained.

8. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 7, characterized in that: When preparing BR-Ph, the volume of the second added solvent is 2-5 times the volume of the current reaction mixture.

9. The method for preparing a high temperature resistant fiber reinforced resin-based composite material according to claim 8, characterized in that: Its bending strength is above 249.87MPa, bending modulus is above 7.75MPa, and impact strength is 63~85KJ / m 2 , interlaminar shear strength is 22~25MPa, T 5％ The thermal decomposition temperature is above 477.95°C and the glass transition temperature is above 411.9°C.

10. A high temperature resistant fiber reinforced resin-based composite material, characterized in that: The composite material is prepared using the method for preparing a high-temperature resistant fiber-reinforced resin-based composite material according to any one of claims 1 to 8.

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