Preparation method of high-temperature-resistant and anti-oxidation phthalonitrile cyano resin

Abstract

The present invention relates to the technical field of phthalonitrile resins, and discloses a preparation method of a high-temperature resistant and anti-oxidation phthalonitrile cyano resin. The present invention thermally cures biphenyl-type bisphthalonitrile and phthalonitrile fluorinated polyetherimide to obtain a high-temperature resistant and anti-oxidation phthalonitrile cyano resin. The phthalonitrile fluorinated polyetherimide contains a heat-resistant triazine ring and an imide ring, and is co-cured and cross-linked into the phthalonitrile resin molecular chain, thereby improving the high-temperature mass loss temperature of the resin and showing better high-temperature resistance. After high-temperature hot air aging, the flexural strength decreases by a small amount, and the retention rate is high, showing better high-temperature resistance and anti-oxidation performance. The phthalonitrile fluorinated polyetherimide contains a hydrophobic trifluoromethyl group, which is cross-linked into the phthalonitrile resin molecular chain to form a hydrophobic cross-linked network, which is beneficial to the hydrophobicity of the resin and reduces water absorption.

Description

Technical Field

[0001] The invention relates to the technical field of phthalonitrile resins, and in particular to a method for preparing a high-temperature-resistant and antioxidant phthalonitrile cyano resin. Background Art

[0002] Nitrile-based resins, primarily including phthalonitrile resins, biphenyl-type bisphthalonitrile resins, bisphenol A-type phthalonitrile resins, and benzoxazine-type phthalonitrile resins, are high-performance thermosetting resins. At high temperatures, cyano groups undergo addition polymerization to form structures such as phthalocyanine rings. These resins exhibit excellent heat resistance and mechanical strength, and are resistant to prolonged thermal oxidation at temperatures of 450°C-500°C. Through molecular structure and formulation design, phthalonitrile resin systems with high load-bearing capacity and low thermal decomposition at high temperatures can be achieved. These systems, when combined with materials such as carbon fiber and glass fiber, can form structural composites that meet the mechanical, heat resistance, and process performance requirements of high-pressure and high-temperature resistant structural materials for supersonic vehicles and submarines, all at moderate material and process costs. They are widely used in aerospace, automotive, and electrical and electronics fields. However, traditional phthalonitrile resins, such as biphenyl-type bisphthalonitrile, suffer from brittleness, poor toughness, and poor bending properties, limiting their development and application.

[0003] Currently, polyarylether nitrile, polyether sulfone, polyetherimide, and the like are primarily used to toughen and modify phthalonitrile resins. Patent application publication number CN114773844A discloses a polyimide-toughened phthalonitrile resin composition, composite material, and preparation method thereof. This invention utilizes a cyano-functional polyimide resin to toughen phthalonitrile resin, addressing the poor compatibility between thermoplastic resins and phthalonitrile resins while simultaneously improving the mechanical properties of the phthalonitrile resin. Compared to the patent, the present invention not only enhances the toughness and mechanical strength of the phthalonitrile resin but also improves its high-temperature resistance and antioxidant properties. Summary of the Invention

[0004] (1) Technical Problems Solved: In view of the deficiencies in the prior art, the present invention provides a method for preparing a phthalonitrile cyano resin having good toughness, high temperature resistance and oxidation resistance.

[0005] (2) In order to solve the above technical problems, the present invention adopts the following technical solution: a preparation method of a high temperature resistant and antioxidant phthalonitrile cyano resin:

[0006] (1) Nitrogen is introduced into the reaction vessel, and N-methylpyrrolidone, 4,4-diphenyl ether dianhydride, fluorinated aminotriazine monomer, and 2,2-bis(3-amino-4-hydroxyphenyl)propane (CAS No. 1220-78-6) are added. The mixture is reacted at room temperature for 18-24 hours. After the reaction, the solution is poured onto a glass plate, thermally cured at 100-300°C for 5-7 hours, and the film is removed to obtain hydroxyl fluorinated polyetherimide. The reaction formula is as follows:

[0007]

[0008] (2) Add N,N-dimethylformamide and hydroxy fluorinated polyetherimide to a reaction vessel, stir and dissolve, then add potassium carbonate and 4-nitrophthalonitrile, react at 80-90°C for 6-12 hours, cool, add water to the solution, precipitate, filter, wash with water and ethanol, and dry to obtain fluorinated polyetherimide. The reaction formula is as follows:

[0009]

[0010] (3) Add N,N-dimethylformamide, biphenyl-type diphthalonitrile, and phthalonitrile fluorinated polyetherimide into the mold, stir, heat-cure at 150-400°C for 18-21 hours, and cool to obtain a high-temperature resistant and antioxidant phthalonitrile cyano resin.

[0011] Furthermore, in (1), the ratio of 4,4-biphenyl ether dianhydride, fluorine-containing aminotriazine monomer, and 2,2-bis(3-amino-4-hydroxyphenyl)propane is 1 mol:(0.567-0.633) mol:(0.05-0.15) mol.

[0012] Furthermore, the preparation method of the fluorine-containing aminotriazine monomer is as follows: nitrogen is introduced into a reaction vessel, water, acetone, 3-nitro-5-(trifluoromethyl)phenol (CAS No. 349-57-5) in a ratio of (3-3.3) mol: (3-3.3) mol: 1 mol, and sodium hydroxide are added, cyanuric chloride is added after stirring, the temperature is raised to 80-90 ° C, and the reaction is refluxed for 6-10 hours. After cooling, the solution is poured into ice water to precipitate the precipitate, filtered, washed with acetone, and then added to ethanol, palladium carbon catalyst is added, hydrazine hydrate is added dropwise, heated to 75-80 ° C, refluxed for 12-18 hours, filtered while hot, the filtrate is cooled, the precipitate is precipitated, filtered, washed with acetone, and dried to obtain a fluorine-containing aminotriazine monomer. The reaction formula is as follows:

[0013]

[0014] Furthermore, the ratio of hydroxyl fluorinated polyetherimide, potassium carbonate and 4-nitrophthalonitrile in (2) is 100 g: (2.2-7) g: (2.6-8.3) g.

[0015] Furthermore, in (3), the ratio of biphenyl-type diphthalonitrile to phthalonitrile fluorinated polyetherimide is 100 g:(5-20) g.

[0016] (3) The present invention has the following technical effects: a fluorine-containing aminotriazine monomer is used as a hyperbranched polyamine monomer, 2,2-bis(3-amino-4-hydroxyphenyl)propane is used as a diamine monomer, and 4,4-biphenyl ether dianhydride is polymerized to obtain a hyperbranched hydroxyl fluorinated polyetherimide, which contains a trifluoromethyl group and has excellent solubility in solvents such as N,N-dimethylformamide, and can make the hydroxyl group react well with 4-nitrophthalonitrile, thereby introducing a large number of phthalonitrile groups into the side chain of the polyetherimide to obtain a hyperbranched phthalonitrile fluorinated polyetherimide, and finally co-thermally cured with biphenyl-type bisphthalonitrile to obtain a high-temperature resistant and antioxidant phthalonitrile cyano resin.

[0017] The fluorinated polyetherimide of the present invention has good solubility in solvents such as N,N-dimethylformamide and can be blended with biphenyl-type bis-phthalonitrile in N,N-dimethylformamide to form a homogeneous dispersion system, so that the polyetherimide is uniformly dispersed in the biphenyl-type bis-phthalonitrile matrix. In addition, during the high-temperature curing process, a large number of phthalonitrile structures in the side chains of the polyetherimide can undergo a co-curing and cross-linking reaction with the biphenyl-type bis-phthalonitrile, thereby improving the compatibility between the two and enhancing the interface bonding strength. In addition, the polyetherimide contains a three-dimensional hyperbranched structure and flexible ether bonds, which can play a good toughening role and significantly improve the toughness and bending strength of the bis-phthalonitrile resin.

[0018] The fluorinated polyetherimide of the present invention contains a heat-resistant triazine ring and an imide ring, which are co-cured and cross-linked into the molecular chain of the phthalonitrile resin, thereby increasing the high-temperature mass loss temperature of the resin and exhibiting better high-temperature resistance. After aging in high-temperature hot air, the flexural strength decreases slightly and has a high retention rate, thereby exhibiting better high-temperature resistance and antioxidant properties.

[0019] The fluorinated polyetherimide of the present invention contains a hydrophobic trifluoromethyl group, which is cross-linked into the molecular chain of the phthalonitrile resin to form a hydrophobic cross-linked network, which is beneficial to the hydrophobicity of the resin and reduces the water absorption rate. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0021] Example 1:

[0022] (1) Nitrogen was introduced into the reaction vessel, 10 mL of water, 40 mL of acetone, 18 mmol of 3-nitro-5-(trifluoromethyl)phenol, and 18 mmol of sodium hydroxide were added, and 6 mmol of cyanuric chloride was added after stirring. The temperature was raised to 80°C, and the mixture was refluxed under condensation for 10 h. After cooling, the solution was poured into ice water to precipitate the precipitate, which was filtered and washed with acetone. The precipitate was then added to 60 mL of ethanol, 0.77 g of palladium-carbon catalyst was added, and 25 mL of hydrazine hydrate (mass fraction 85%) was added dropwise. The mixture was heated to 75°C, and the mixture was refluxed under condensation for 12 h. The mixture was filtered while hot, and the filtrate was cooled to precipitate the precipitate, which was filtered, washed with acetone, and dried to obtain a fluorine-containing aminotriazine monomer.

[0023] (2) Nitrogen was introduced into the reaction vessel, and 40 mL of N-methylpyrrolidone, 10 mmol of 4,4-biphenyl ether dianhydride, 6 mmol of fluorinated aminotriazine monomer, and 1 mmol of 2,2-bis(3-amino-4-hydroxyphenyl)propane were added and reacted at room temperature for 18 h. After the reaction, the solution was poured onto a glass plate and cured at 100 ° C for 0.5 h, 150 ° C for 1 h, 220 ° C for 2 h, 260 ° C for 2 h, and 300 ° C for 0.5 h. The film was removed to obtain hydroxy fluorinated polyetherimide.

[0024] (3) Add 300 mL of N,N-dimethylformamide and 20 g of hydroxy fluorinated polyetherimide to the reaction container, stir and dissolve (soluble), then add 0.92 g of potassium carbonate and 1.13 g of 4-nitrophthalonitrile, react at 80 ° C for 12 hours, cool and add water to the solution to precipitate, filter and wash with water and ethanol, and dry to obtain fluorinated polyetherimide.

[0025] (4) Add 100 mL of N,N-dimethylformamide and 100 g of biphenyl-type diphthalonitrile (structural formula: ), 5g of phthalonitrile fluorinated polyetherimide, after stirring and dissolving (soluble), cure at 150°C for 1h, 200°C for 2h, 250°C for 2h, 300°C for 3h, 340°C for 4h, 370°C for 3h, and heat cure at 400°C for 3h, cool to obtain high temperature resistant and antioxidant phthalonitrile cyano resin.

[0026] Example 2:

[0027] (1) Nitrogen was introduced into the reaction vessel, 15 mL of water, 40 mL of acetone, 19.8 mmol of 3-nitro-5-(trifluoromethyl)phenol, and 19.8 mmol of sodium hydroxide were added, and 6 mmol of cyanuric chloride was added after stirring. The temperature was raised to 90°C, and the mixture was refluxed under condensation for 6 h. After cooling, the solution was poured into ice water to precipitate the precipitate, which was filtered and washed with acetone. The precipitate was then added to 70 mL of ethanol, 0.72 g of palladium-carbon catalyst was added, and 30 mL of hydrazine hydrate (mass fraction 85%) was added dropwise. The mixture was heated to 80°C, and the mixture was refluxed under condensation for 18 h. The mixture was filtered while hot, and the filtrate was cooled to precipitate the precipitate, which was filtered, washed with acetone, and dried to obtain a fluorine-containing aminotriazine monomer.

[0028] (2) Nitrogen was introduced into the reaction vessel, and 50 mL of N-methylpyrrolidone, 10 mmol of 4,4-biphenyl ether dianhydride, 5.67 mmol of fluorinated aminotriazine monomer, and 1.5 mmol of 2,2-bis(3-amino-4-hydroxyphenyl)propane were added and reacted at room temperature for 24 h. After the reaction, the solution was poured onto a glass plate and cured at 100 ° C for 1 h, 150 ° C for 1 h, 220 ° C for 2 h, 260 ° C for 1 h, and heat-cured at 300 ° C for 0.5 h. The film was removed to obtain hydroxy fluorinated polyetherimide.

[0029] (3) Add 300 mL of N,N-dimethylformamide and 20 g of hydroxy fluorinated polyetherimide to the reaction vessel, stir and dissolve (soluble), then add 1.4 g of potassium carbonate and 1.66 g of 4-nitrophthalonitrile, react at 90 ° C for 10 hours, cool and add water to the solution to precipitate, filter and wash with water and ethanol, and dry to obtain fluorinated polyetherimide.

[0030] (4) Add 120 mL of N,N-dimethylformamide, 100 g of biphenyl-type diphthalonitrile, and 12 g of phthalonitrile fluorinated polyetherimide into the mold, stir and dissolve (soluble), and then cure at 150°C for 1 hour, 200°C for 2 hours, 250°C for 3 hours, 300°C for 4 hours, 340°C for 4 hours, 370°C for 4 hours, and heat cure at 400°C for 3 hours. Cool to obtain a high-temperature resistant and antioxidant phthalonitrile cyano resin.

[0031] Example 3:

[0032] (1) Nitrogen was introduced into the reaction vessel, and 50 mL of N-methylpyrrolidone, 10 mmol of 4,4-biphenyl ether dianhydride, 6.33 mmol of fluorine-containing aminotriazine monomer (prepared according to the method of Example 1), and 0.5 mmol of 2,2-bis(3-amino-4-hydroxyphenyl)propane were added and reacted at room temperature for 24 h. After the reaction, the solution was poured onto a glass plate and cured at 100 ° C for 1 h, 150 ° C for 2 h, 220 ° C for 2 h, 260 ° C for 1 h, and heat-cured at 300 ° C for 0.5 h. The film was removed to obtain hydroxyl fluorine-containing polyetherimide.

[0033] (2) Add 250 mL of N,N-dimethylformamide and 20 g of hydroxy fluorinated polyetherimide to a reaction vessel, stir and dissolve (soluble), then add 0.44 g of potassium carbonate and 0.52 g of 4-nitrophthalonitrile, react at 85 ° C for 6 hours, cool and add water to the solution to precipitate, filter and wash with water and ethanol, and dry to obtain fluorinated polyetherimide.

[0034] (3) Add 150 mL of N,N-dimethylformamide, 100 g of biphenyl-type diphthalonitrile, and 20 g of phthalonitrile fluorinated polyetherimide into the mold, stir and dissolve (soluble), and then cure at 150°C for 1 hour, 200°C for 2 hours, 250°C for 3 hours, 300°C for 4 hours, 340°C for 4 hours, 370°C for 4 hours, and heat cure at 400°C for 3 hours. Cool to obtain a high-temperature resistant and antioxidant phthalonitrile cyano resin.

[0035] Comparative Example 1:

[0036] (1) Add 100 mL of N,N-dimethylformamide and 5 g of phthalonitrile fluorinated polyetherimide into the mold, cure at 150°C for 1 h, cure at 200°C for 2 h, cure at 250°C for 2 h, cure at 300°C for 3 h, cure at 340°C for 4 h, cure at 370°C for 3 h, and heat cure at 400°C for 3 h, and cool to obtain phthalonitrile cyano resin.

[0037] Comparative Example 2:

[0038] (1) Nitrogen was introduced into the reaction vessel, and 40 mL of N-methylpyrrolidone, 10 mmol of 4,4-biphenyl ether dianhydride, and 6 mmol of 2,4,6-tris(4-aminophenoxy)-1,3,5-triazine (CAS No. 22065-34-5, structural formula: ), 1mmol 2,2-bis(3-amino-4-hydroxyphenyl)propane, react at room temperature for 18h, pour the solution onto a glass plate after the reaction, cure it at 100°C for 0.5h, 150°C for 1h, 220°C for 2h, 260°C for 2h, and heat cure it at 300°C for 0.5h, demold to obtain hydroxy polyetherimide.

[0039] (2) Add 300 mL of N,N-dimethylformamide and 20 g of hydroxypolyetherimide to the reaction container, stir (undissolved), add 0.92 g of potassium carbonate and 1.13 g of 4-nitrophthalonitrile, react at 80 ° C for 12 hours, cool, add water to the solution, precipitate, filter, wash with water and ethanol, and dry to obtain modified polyetherimide.

[0040] (3) Add 100 mL of N,N-dimethylformamide, 100 g of biphenyl-type diphthalonitrile, and 5 g of modified polyetherimide into the mold, stir (undissolved), and cure at 150°C for 1 h, 200°C for 2 h, 250°C for 2 h, 300°C for 3 h, 340°C for 4 h, 370°C for 3 h, and heat cure at 400°C for 3 h, and cool to obtain diphthalonitrile cyano resin.

[0041] Comparative Example 3:

[0042] (1) Nitrogen was introduced into the reaction vessel, and 40 mL of N-methylpyrrolidone, 10 mmol of 4,4-biphenyl ether dianhydride, and 9 mmol of 4,4'-[1,4-phenylbis(oxy)]bis[3-(trifluoromethyl)aniline] (CAS No. 22065-34-5, structural formula: ), 1mmol 2,2-bis(3-amino-4-hydroxyphenyl)propane, react at room temperature for 18h, pour the solution onto a glass plate, cure it at 100°C for 0.5h, 150°C for 1h, 220°C for 2h, 260°C for 2h, and heat cure it at 300°C for 0.5h, demold to obtain hydroxy fluorinated polyetherimide.

[0043] (2) Add 300 mL of N,N-dimethylformamide and 20 g of hydroxy fluorinated polyetherimide to the reaction container, stir and dissolve (if soluble), then add 0.92 g of potassium carbonate and 1.13 g of 4-nitrophthalonitrile, react at 80 ° C for 12 hours, cool and add water to the solution to precipitate, filter and wash with water and ethanol, and dry to obtain fluorinated polyetherimide.

[0044] (3) Add 100 mL of N,N-dimethylformamide, 100 g of biphenyl-type diphthalonitrile, and 5 g of phthalonitrile fluorinated polyetherimide into the mold, stir (dissolved), and cure at 150°C for 1 h, 200°C for 2 h, 250°C for 2 h, 300°C for 3 h, 340°C for 4 h, 370°C for 3 h, and heat cure at 400°C for 3 h, and cool to obtain phthalonitrile cyano resin.

[0045] The phthalonitrile cyano resin was placed in a thermogravimetric analyzer and tested in nitrogen at a heating rate of 10°C / min.

[0046] Add 200 mL of water and 5 g of phthalonitrile cyano resin to a reaction vessel, heat to 95°C, condense and reflux for 48 hours, take out the resin, wipe off excess water on the surface, weigh it, and calculate the water absorption rate Q.

[0047] Q = (mass after water absorption - mass before water absorption) ÷ mass before water absorption × 100%.

[0048] The bending properties of phthalonitrile cyano resin were tested according to GB / T 9341-2000. The phthalonitrile cyano resin was heat treated at 300°C for 72 hours in a forced air dryer, cooled to room temperature, and then tested for bending properties.

[0049] Table 1

[0050]

[0051] As can be seen from the above table, the biphenyl-type diphthalonitrile of Comparative Example 1 has a large water absorption rate, a low 5% mass loss temperature and a low bending strength. Moreover, after high-temperature hot air aging, the bending strength decreases significantly, the retention rate is low, and the high temperature resistance and antioxidant properties are poor.

[0052] The biphenyl-type bisphthalonitrile of Examples 1-3 is added with a fluorinated polyetherimide containing trifluoromethyl groups, which can give the polyetherimide good solubility and good solubility in solvents such as N,N-dimethylformamide. It can be blended with the biphenyl-type bisphthalonitrile in N,N-dimethylformamide to form a homogeneous dispersion system, so that the polyetherimide is uniformly dispersed in the biphenyl-type bisphthalonitrile matrix. In addition, during the high-temperature curing process, the large amount of phthalonitrile structures on the side chains of the polyetherimide can undergo a co-curing cross-linking reaction with the biphenyl-type bisphthalonitrile, thereby improving the compatibility between the two and enhancing the interfacial bonding strength. At the same time, the polyetherimide contains a three-dimensional hyperbranched structure and a flexible ether bond, which can play a good toughening role and significantly improve the toughness and flexural strength of the bisphthalonitrile resin. The polyetherimide contains heat-resistant triazine and imide rings, which co-curing and cross-linking react with the phthalonitrile resin molecular chain, raising the resin's 5% mass loss temperature and exhibiting improved high-temperature resistance. After hot air aging, the flexural strength shows minimal decline, with high retention and excellent high-temperature and antioxidant properties. Furthermore, the phthalonitrile fluorinated polyetherimide contains hydrophobic trifluoromethyl groups, which cross-link with the phthalonitrile resin molecular chain to form a hydrophobic cross-linking network, which improves the resin's hydrophobicity and reduces water absorption.

[0053] Comparative Example 2 uses 2,4,6-tris(4-aminophenoxy)-1,3,5-triazine as a hyperbranched polyamine monomer, and the prepared hydroxy polyetherimide does not contain a trifluoromethyl group, has poor solubility in N,N-dimethylformamide solvent, and is difficult to effectively react with 4-nitrophthalonitrile. The side chain of the modified polyetherimide obtained does not contain a large number of phthalonitrile groups, and cannot undergo a good co-curing reaction with biphenyl-type diphthalonitrile, resulting in poor compatibility between the two, low interfacial bonding strength, poor toughening effect of polyetherimide, low bending strength of phthalonitrile resin, and high water absorption.

[0054] Comparative Example 3 utilizes 4,4'-[1,4-phenylbis(oxy)]bis[3-(trifluoromethyl)aniline] as the diamine monomer. The resulting fluorinated polyetherimide (PEI) exhibits good solubility in N,N-dimethylformamide. The abundant PEI side chains allow for co-curing and cross-linking with biphenyl bis-PEI, enhancing compatibility and interfacial bonding strength, which contributes to improved toughness and flexural strength of the PEI resin. However, its flexural strength is lower than that of Example 1, primarily because the PEI in Comparative Example 3 lacks a three-dimensional hyperbranched structure, resulting in poor toughening. Furthermore, the 5% mass loss temperature is lower than that of Example 1 because the PEI lacks a heat-resistant triazine ring structure. However, the mass loss temperature is slightly higher than that of Comparative Example 2, mainly because the side chain of the polyetherimide in Comparative Example 3 contains a large amount of phthalonitrile structure, which can undergo a co-curing and cross-linking reaction with biphenyl-type diphthalonitrile, which is beneficial to improving the high temperature resistance of the phthalonitrile resin.

[0055] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing a high-temperature resistant and antioxidant phthalonitrile cyano resin, characterized in that: The preparation method is as follows: (1) nitrogen is introduced into a reaction vessel, and N-methylpyrrolidone, 4,4-biphenyl ether dianhydride, fluorine-containing aminotriazine monomer, and 2,2-bis(3-amino-4-hydroxyphenyl)propane are added. After the reaction, the solution is poured onto a glass plate, thermally cured, and demolded to obtain a hydroxyl fluorine-containing polyetherimide; (2) adding N,N-dimethylformamide and the hydroxy fluorinated polyetherimide prepared in (1) above into a reaction vessel, stirring and dissolving, and then adding potassium carbonate and 4-nitrophthalonitrile. After the reaction, adding water to the solution to precipitate the precipitate, filtering, washing, and drying to obtain phthalonitrile fluorinated polyetherimide; (3) Add N,N-dimethylformamide, biphenyl-type diphthalonitrile, and the phthalonitrile fluorinated polyetherimide prepared in (2) into the mold, stir, heat-cure, and cool to obtain a high-temperature resistant and antioxidant phthalonitrile cyano resin; The preparation method of the fluorine-containing aminotriazine monomer comprises the following steps: introducing nitrogen into a reaction container, adding water, acetone, 3-nitro-5-(trifluoromethyl)phenol, and sodium hydroxide, stirring, adding cyanuric chloride, heating to 80-90° C., condensing and refluxing for 6-10 hours, cooling, pouring the solution into ice water, precipitating a precipitate, filtering, and washing, then adding the solution to ethanol, adding a palladium-carbon catalyst, adding hydrazine hydrate dropwise, heating to 75-80° C., condensing and refluxing for 12-18 hours, filtering while hot, cooling the filtrate, precipitating a precipitate, filtering, washing, and drying to obtain the fluorine-containing aminotriazine monomer; The ratio of the 3-nitro-5-(trifluoromethyl)phenol, sodium hydroxide and cyanuric chloride is (3-3.3) mol: (3-3.3) mol: 1 mol.

2. The method for preparing the high temperature resistant and antioxidant phthalonitrile cyano resin according to claim 1, wherein The reaction in (1) is carried out at room temperature for 18-24 hours; and thermal curing is carried out at 100-300° C. for 5-7 hours.

3. The preparation method of the high temperature resistant and antioxidant phthalonitrile cyano resin according to claim 1, wherein The ratio of 4,4-biphenyl ether dianhydride, fluorine-containing aminotriazine monomer and 2,2-bis(3-amino-4-hydroxyphenyl)propane in (1) is 1 mol: (0.567-0.633) mol: (0.05-0.15) mol.

4. The method for preparing the high temperature resistant and antioxidant phthalonitrile cyano resin according to claim 1, wherein The ratio of hydroxy fluorinated polyetherimide, potassium carbonate and 4-nitrophthalonitrile in (2) is 100g:(2.2-7)g:(2.6-8.3)g.

5. The method for preparing the high temperature resistant and antioxidant phthalonitrile cyano resin according to claim 1, wherein The reaction in (2) is carried out at 80-90°C for 6-12 hours.

6. The method for preparing the high temperature resistant and antioxidant phthalonitrile cyano resin according to claim 1, wherein The ratio of biphenyl type diphthalonitrile to phthalonitrile fluorinated polyetherimide in (3) is 100g:(5-20)g.

7. The method for preparing the high temperature resistant and antioxidant phthalonitrile cyano resin according to claim 1, wherein: The heat curing in (3) is carried out at 150-400° C. for 18-21 hours.

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