High-performance flame retardant suitable for composite material and preparation method of high-performance flame retardant

Abstract

The invention relates to the technical field of flame retardants, in particular to a high-performance flame retardant suitable for a composite material and a preparation method thereof, and the high-performance flame retardant comprises the following raw materials in parts by weight: 45-55 parts of isocyanate, 45-55 parts of polypropylene triol, 5-10 parts of dimethyl methylphosphonate and 2-10 parts of an additive. According to the invention, a base material of the additive is generated from hydrogenated tallow amine polyoxyethylene ether, KH560, KH792 and other components, the interface bonding force between flame retardant molecules and a matrix is enhanced, KH570 modified composite hydroxide, nano-silica and the like form a filler, and through wrapping and bridging of the base material in the additive, nano-scale uniform dispersion in the matrix is realized, and the base material and the nano-silica cooperate with each other, so that the flame retardant performance is improved. A firm anchoring and dispersing structure is constructed between the flame retardant and a composite material matrix, and migration and precipitation of the flame retardant due to weak interface bonding force are effectively inhibited, so that the durability of the flame retardant property is ensured.

Description

Technical Field

[0001] This invention relates to the field of flame retardant technology, specifically to a high-performance flame retardant suitable for composite materials and its preparation method. Background Technology

[0002] Flame retardants are functional additives that impart flame-retardant properties to flammable polymers. They are mainly designed for polymer materials. There are many types of flame retardants, which can be classified into additive flame retardants and reactive flame retardants according to their application methods. Additive flame retardants are added to polymers through mechanical mixing, while reactive flame retardants participate in the polymerization reaction as monomers, making the polymer itself contain flame-retardant components.

[0003] In existing technologies, insufficient interfacial compatibility between flame retardants and the composite matrix leads to difficulties in the uniform dispersion of flame retardants within the matrix. This results in migration and precipitation due to weak interfacial bonding during long-term use, thereby reducing the long-term stability of the flame-retardant effect of the composite material. Therefore, this invention provides a high-performance flame retardant suitable for composite materials and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-performance flame retardant suitable for composite materials and its preparation method. The high-performance flame retardant suitable for composite materials prepared by this invention not only has good flame retardant properties, but also good compressive strength.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-performance flame retardant suitable for composite materials, comprising the following raw materials in parts by weight: 45-55 parts isocyanate, 45-55 parts polypropylene triol, 5-10 parts dimethyl methylphosphonate, and 2-10 parts additives. The additive is prepared by the following method: S1: Base material preparation, the raw materials of the base material include hydrogenated tallow amine polyoxyethylene ether, isopropanol, KH560, KH792 and sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution; S2: Filler preparation, the raw materials of the filler include composite powder, nano silica, expandable graphite and mixed liquid; S3: Mixing treatment, the base material and filler are mixed to obtain the additive.

[0006] Preferably, the method for preparing the base material is as follows: hydrogenated tallow amine polyoxyethylene ether and isopropanol are added to a reactor, heated to 60-80℃ for 3-5 hours to dissolve, then a mixture of KH560, KH792 and isopropanol is added, mixed well, and then an aqueous solution of sodium 3-chloro-2-hydroxypropyl sulfonate is added. The temperature is set to 70-80℃, and the mixture is stirred and reacted for 4-5 hours. The isopropanol and water are evaporated to dryness under normal pressure to obtain the base material.

[0007] Preferably, the mass ratio of hydrogenated tallow amine polyoxyethylene ether to isopropanol is 1:2-3, the molar ratio of hydrogenated tallow amine polyoxyethylene ether, KH560, KH792 and sodium 3-chloro-2-hydroxypropyl sulfonate is 1:0.7-0.8:0.2-0.3:1-1.2, the mass fraction of the aqueous solution of sodium 3-chloro-2-hydroxypropyl sulfonate is 28-38%, and the amount of isopropanol added to the mixture of KH560, KH792 and isopropanol is 60-80% of the total mass of KH560 and KH792.

[0008] Preferably, the filler is prepared by adding composite powder, nano-silica and expandable graphite into a mixer, stirring the mixer at 80-100 rpm for 20-30 minutes, then adding a mixed liquid, and stirring the mixer at 100-200 rpm for 40-60 minutes to obtain the filler.

[0009] Preferably, the mass ratio of composite powder, nano-silica and expandable graphite is 1:0.2-0.3:0.15-0.25, and the mass of the mixture is 10-15% of the mass of the composite powder.

[0010] Preferably, the composite powder is prepared by mixing aluminum hydroxide and magnesium hydroxide, and the mixture is prepared by mixing KH570 and anhydrous ethanol, wherein the mass ratio of aluminum hydroxide to magnesium hydroxide is 1:1-2, and the mass ratio of KH570 to anhydrous ethanol is 1:1.

[0011] Preferably, the mixing process is as follows: the base material is put into a mixer, heated to 75-85℃, and stirred at 20-40 rpm for 20-30 minutes. Then, the filler is added in three batches. The first batch contains 50% of the total mass. After mixing evenly, the second batch contains 25% of the total mass. After mixing evenly, the third batch contains another 25% of the total mass. During the addition of the filler, the stirring speed is gradually adjusted to 300-500 rpm. After the filler is added, the stirring speed is increased to 800-1000 rpm. The temperature is maintained at 75-85℃, and the mixture is stirred for 60-80 minutes. After the product is cooled to room temperature, it is pulverized to complete the mixing process and obtain the additive.

[0012] Preferably, the isocyanate is selected from at least one of hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-diphenylmethane diisocyanate.

[0013] Preferably, the polypropylene triol has an average molecular weight of 3000-5000 and a hydroxyl value of 100-120 mgKOH / g.

[0014] Preferably, a method for preparing a high-performance flame retardant suitable for composite materials includes the following steps: under dry nitrogen protection, isocyanate and polypropylene triol are added to a reactor and stirred at 300-500 rpm for 2-3 hours at 60-70°C. Then, the temperature is lowered to 40-50°C, dimethyl methylphosphonate is added first, and the mixture is stirred for 10-15 minutes. Then, additives are added, and the mixture is stirred for 30-60 minutes under a vacuum of -0.08 MPa. After that, the vacuum is released, the mixture is discharged under nitrogen protection, sealed and packaged to obtain a high-performance flame retardant suitable for composite materials.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, the additive base material is generated from components such as hydrogenated tallow amine polyoxyethylene ether, KH560, and KH792. The molecular structure simultaneously introduces long-chain alkyl, siloxane, and sulfonic acid groups, which have excellent chemical affinity with the application matrix such as polyurethane, enhancing the interfacial bonding force between the flame retardant molecules and the matrix. Furthermore, KH570-modified composite hydroxide and nano-silica constitute fillers. Through the encapsulation and bridging of the base material in the additive, nanoscale uniform dispersion in the matrix is ​​achieved. The two work synergistically to construct a strong anchoring and dispersion structure between the flame retardant and the composite matrix, effectively inhibiting the migration and precipitation of the flame retardant due to weak interfacial bonding force, thereby ensuring the durability of flame retardant performance.

[0016] 2. In this invention, isocyanate and polypropylene triol constitute the polymer matrix, dimethyl methylphosphonate acts as a phosphorus-based flame retardant in both the gas and condensed phases, the composite hydroxide in the additives decomposes and absorbs heat and releases water vapor when heated, nano-silica helps to form a dense and stable char layer, and expandable graphite expands rapidly when heated to form a heat insulation barrier. These components play a flame retardant role in the gas phase by diluting combustible gases and capturing free radicals, and in the condensed phase by promoting char formation and providing heat insulation, ultimately enabling the composite material to obtain excellent anti-ignition, smoke suppression and anti-dripping capabilities.

[0017] 3. In this invention, the flame retardant matrix is ​​composed of a rigid skeleton formed by a polyurethane structure of isocyanate and polypropylene triol. The silane coupling agents KH560 and KH792 in the additives are hydrolyzed to generate a three-dimensional siloxane network, which interpenetrates and reinforces the matrix. The nano-silica and KH570 modified composite hydroxide particles in the filler are uniformly dispersed and embedded in the matrix under high-speed shearing process, which plays a nano-reinforcing effect. The optimized mixing process ensures a strong interfacial bond between the filler and the matrix. The synergistic effect of multiple parties gives the flame retardant particle structure good mechanical properties, making it less prone to pulverization during packaging, transportation and storage. Attached Figure Description

[0018] Figure 1The present invention provides a flowchart of a method for preparing a high-performance flame retardant suitable for composite materials. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that the raw materials used in the following embodiments are all commercially available.

[0021] Example 1: A high-performance flame retardant suitable for composite materials comprises the following raw materials in parts by weight: 45 parts isocyanate, 45 parts polypropylene triol, 5 parts dimethyl methylphosphonate, and 2 parts additives. The isocyanate selected is hexamethylene diisocyanate. Among them, the average molecular weight of polypropylene triol is 3000 and the hydroxyl value is 100mgKOH / g; The additive is prepared by the following method: S1: Base material preparation, the raw materials of the base material include hydrogenated tallow amine polyoxyethylene ether, isopropanol, KH560, KH792 and sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution; The method for preparing the base material is as follows: Hydrogenated tallow amine polyoxyethylene ether and isopropanol are added to a reactor at a mass ratio of 1:2. The mixture is heated at 60℃ for 3 hours to dissolve the materials. Then, a mixture of KH560, KH792, and isopropanol is added and mixed thoroughly. An aqueous solution of sodium 3-chloro-2-hydroxypropyl sulfonate is then added. The mixture is stirred at 70℃ for 4 hours. The isopropanol and water are evaporated to dryness under normal pressure to obtain the base material. The molar ratio of hydrogenated tallow amine polyoxyethylene ether, KH560, KH792, and sodium 3-chloro-2-hydroxypropyl sulfonate is 1:0.7:0.2:1. The mass fraction of the sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution is 28%. The amount of isopropanol added to the mixture of KH560, KH792, and isopropanol is 60% of the total mass of KH560 and KH792. S2: Filler preparation, the raw materials of the filler include composite powder, nano silica, expandable graphite and mixed liquid; The filler is prepared by adding composite powder, nano-silica and expandable graphite into a mixer at a mass ratio of 1:0.2:0.15. The mixer is set to 80 rpm and stirred for 20 min. Then, a mixture of 10% of the mass of composite powder is added and the mixer is set to 100 rpm and stirred for 40 min to obtain the filler.

[0022] The composite powder is prepared by mixing aluminum hydroxide and magnesium hydroxide, and the mixture is prepared by mixing KH570 and anhydrous ethanol. The mass ratio of aluminum hydroxide to magnesium hydroxide is 1:1, and the mass ratio of KH570 to anhydrous ethanol is 1:1. S3: Mixing treatment, the base material and filler are mixed to obtain the additive.

[0023] The mixing process is as follows: the base material is put into a mixer, heated to 75°C, and stirred at 20 rpm for 20 minutes. Then, the filler is added in three batches. The first batch is 50% of the total mass. After mixing evenly, the next batch of 25% of the total mass is added. After mixing evenly, the next batch of 25% of the total mass is added. During the addition of the filler, the stirring speed is gradually increased to 300 rpm. After the filler is added, the stirring speed is increased to 800 rpm. The temperature is maintained at 75°C and stirred for 60 minutes. After the product is cooled to room temperature, it is pulverized to complete the mixing process and obtain the additive.

[0024] A method for preparing a high-performance flame retardant suitable for composite materials includes the following steps: under dry nitrogen protection, isocyanate and polypropylene triol are added to a reactor and stirred at 300 rpm for 2 h at 60 °C. Then, the temperature is lowered to 40 °C, dimethyl methylphosphonate is added first and stirred for 10 min, then additives are added and stirred for 30 min under a vacuum of -0.08 MPa. After that, the vacuum is released, the material is discharged under nitrogen protection, sealed and packaged to obtain a high-performance flame retardant suitable for composite materials.

[0025] Example 2: A high-performance flame retardant suitable for composite materials comprises the following raw materials in parts by weight: 50 parts isocyanate, 50 parts polypropylene triol, 8 parts dimethyl methylphosphonate, and 6 parts additives. The isocyanate selected isophorone diisocyanate; The average molecular weight of polypropylene triol is 4000, and the hydroxyl value is 110 mgKOH / g. The additive is prepared by the following method: S1: Base material preparation, the raw materials of the base material include hydrogenated tallow amine polyoxyethylene ether, isopropanol, KH560, KH792 and sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution; The method for preparing the base material is as follows: Hydrogenated tallow amine polyoxyethylene ether and isopropanol are added to a reactor at a mass ratio of 1:2.5. The mixture is heated at 70℃ for 4 hours to dissolve the materials. Then, a mixture of KH560, KH792, and isopropanol is added and mixed thoroughly. An aqueous solution of sodium 3-chloro-2-hydroxypropyl sulfonate is then added. The mixture is stirred at 75℃ for 4.5 hours. The isopropanol and water are evaporated to dryness under normal pressure to obtain the base material. The molar ratio of hydrogenated tallow amine polyoxyethylene ether, KH560, KH792, and sodium 3-chloro-2-hydroxypropyl sulfonate is 1:0.75:0.25:1.1. The mass fraction of the sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution is 33%. The amount of isopropanol added to the mixture of KH560, KH792, and isopropanol is 70% of the total mass of KH560 and KH792. S2: Filler preparation, the raw materials of the filler include composite powder, nano silica, expandable graphite and mixed liquid; The filler is prepared by adding composite powder, nano-silica and expandable graphite into a mixer at a mass ratio of 1:0.25:0.2. The mixer is set to 90 rpm and stirred for 25 min. Then, a mixture of 12% of the mass of composite powder is added and the mixer is set to 150 rpm and stirred for 50 min to obtain the filler.

[0026] The composite powder is prepared by mixing aluminum hydroxide and magnesium hydroxide, and the mixture is prepared by mixing KH570 and anhydrous ethanol. The mass ratio of aluminum hydroxide to magnesium hydroxide is 1:1.5, and the mass ratio of KH570 to anhydrous ethanol is 1:1. S3: Mixing treatment, the base material and filler are mixed to obtain the additive.

[0027] The mixing process is as follows: the base material is put into a mixer, heated to 80°C, and stirred at 30 rpm for 25 minutes. Then, the filler is added in three batches. The first batch is 50% of the total mass. After mixing evenly, the second batch is 25% of the total mass. After mixing evenly, the third batch is 25% of the total mass. During the addition of filler, the stirring speed is gradually increased to 400 rpm. After the filler is added, the stirring speed is increased to 900 rpm. The temperature is maintained at 80°C and stirred for 70 minutes. After the product is cooled to room temperature, it is pulverized to complete the mixing process and obtain the additive.

[0028] A method for preparing a high-performance flame retardant suitable for composite materials includes the following steps: under dry nitrogen protection, isocyanate and polypropylene triol are added to a reactor and stirred at 400 rpm for 2.5 h at 65 °C. Then, the temperature is lowered to 45 °C, dimethyl methylphosphonate is added first and stirred for 12 min, then additives are added and stirred under a vacuum of -0.08 MPa for 45 min. After that, the vacuum is released, the material is discharged under nitrogen protection, sealed and packaged to obtain a high-performance flame retardant suitable for composite materials.

[0029] Example 3: A high-performance flame retardant suitable for composite materials comprises the following raw materials in parts by weight: 55 parts isocyanate, 55 parts polypropylene triol, 10 parts dimethyl methylphosphonate, and 10 parts additives. The isocyanate selected is 4,4'-diphenylmethane diisocyanate; Among them, the average molecular weight of polypropylene triol is 5000 and the hydroxyl value is 120mgKOH / g; The additive is prepared by the following method: S1: Base material preparation, the raw materials of the base material include hydrogenated tallow amine polyoxyethylene ether, isopropanol, KH560, KH792 and sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution; The method for preparing the base material is as follows: Hydrogenated tallow amine polyoxyethylene ether and isopropanol are added to a reactor at a mass ratio of 1:3. The mixture is heated at 80℃ for 5 hours to dissolve the materials. Then, a mixture of KH560, KH792, and isopropanol is added and mixed thoroughly. An aqueous solution of sodium 3-chloro-2-hydroxypropyl sulfonate is then added. The mixture is stirred at 80℃ for 5 hours. The isopropanol and water are evaporated to dryness under normal pressure to obtain the base material. The molar ratio of hydrogenated tallow amine polyoxyethylene ether, KH560, KH792, and sodium 3-chloro-2-hydroxypropyl sulfonate is 1:0.8:0.3:1.2. The mass fraction of the sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution is 38%. The amount of isopropanol added to the mixture of KH560, KH792, and isopropanol is 80% of the total mass of KH560 and KH792. S2: Filler preparation, the raw materials of the filler include composite powder, nano silica, expandable graphite and mixed liquid; The filler is prepared by adding composite powder, nano-silica and expandable graphite into a mixer at a mass ratio of 1:0.3:0.25. The mixer is set to 100 rpm and stirred for 30 minutes. Then, a mixture of 15% of the mass of composite powder is added and the mixer is set to 200 rpm and stirred for 60 minutes to obtain the filler.

[0030] The composite powder is prepared by mixing aluminum hydroxide and magnesium hydroxide, and the mixture is prepared by mixing KH570 and anhydrous ethanol. The mass ratio of aluminum hydroxide to magnesium hydroxide is 1:2, and the mass ratio of KH570 to anhydrous ethanol is 1:1. S3: Mixing treatment, the base material and filler are mixed to obtain the additive.

[0031] The mixing process is as follows: the base material is put into a mixer, heated to 85°C, and stirred at 40 rpm for 30 minutes. Then, the filler is added in three batches. The first batch is 50% of the total mass. After mixing evenly, the second batch is 25% of the total mass. After mixing evenly, the third batch is 25% of the total mass. During the addition of filler, the stirring speed is gradually increased to 500 rpm. After the filler is added, the stirring speed is increased to 1000 rpm. The temperature is maintained at 85°C and stirred for 80 minutes. After the product is cooled to room temperature, it is pulverized to complete the mixing process and obtain the additive.

[0032] A method for preparing a high-performance flame retardant suitable for composite materials includes the following steps: under dry nitrogen protection, isocyanate and polypropylene triol are added to a reactor and stirred at 500 rpm for 3 h at 70 °C. Then, the temperature is lowered to 50 °C, dimethyl methylphosphonate is added first and stirred for 15 min, then additives are added and stirred for 60 min under a vacuum of -0.08 MPa. After that, the vacuum is released, the material is discharged under nitrogen protection, sealed and packaged to obtain a high-performance flame retardant suitable for composite materials.

[0033] Comparative Example 1: The difference between this comparative example and Example 1 is that this comparative example does not contain a base material.

[0034] Comparative Example 2 differs from Example 1 in that it does not contain filler.

[0035] Comparative Example 3: The difference between this comparative example and Example 1 is that this comparative example does not contain any additives.

[0036] Performance testing: The flame retardants prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, and the test data are recorded in the table below: Table 1:

[0037] In performance testing, the limiting oxygen index (LOI, %) is based on GB / T 2406.2-2009 standard. The higher the value, the more difficult the material is to burn. The vertical burning test is based on GB / T 2408-2008, and the compressive strength test is based on GB / T 1041-2008. The main evaluation criteria are the flame retardant's ability to resist crushing, reflecting its ability to maintain physical integrity during actual packaging, stacking, and transportation.

[0038] It is evident that the limiting oxygen index, vertical burning rating, and compressive strength of the flame retardants prepared in Comparative Examples 1-3 are all inferior to those in Examples 1-3. Among the data on limiting oxygen index and vertical burning rating related to flame retardant performance, the data of Examples 1-3 are the best, indicating that the additive system with synergistic effects of base material and filler has an overall advantage. The base material provides interfacial bonding to ensure that components do not migrate, while the filler provides multiple flame retardant mechanisms to achieve efficient synergy. However, the performance of Comparative Example 1 decreased significantly after the base material was missing, indicating that the filler and matrix have extremely poor compatibility after the base material is missing, making it easy to migrate and unable to effectively accumulate at the combustion interface to play a role. The data of Comparative Example 2 decreased after the filler was missing. Although it was better than Comparative Example 1 and Comparative Example 3, it still had a large gap with the data of Examples 1-3. This indicates that the base material itself contributes to the improvement of the interface, but the flame retardant performance is still greatly reduced after the filler is missing. The absence of additives in Example 3 means that both filler and auxiliary materials are missing at the same time, so it is unsurprisingly at the worst level. In the data on compressive strength related to mechanical properties, Examples 1-3 showed moderate compressive strength, indicating that the flame retardant has sufficient strength to resist general compression and friction during storage and transportation, is not prone to pulverization, and is not too hard to affect processing. This is due to its stable organic skeleton and composite structure reinforced by nanofillers. However, the strength of Comparative Example 1, which lacks the base material, decreased significantly, indicating that the lack of organic binder between filler particles after the base material was removed resulted in a loose structure, poor strength, and easy pulverization. The strength of Comparative Example 2 decreased after the filler was removed, but it was still significantly better than that of Comparative Examples 1 and 3. This indicates that the organic network formed by the base material alone has a certain strength, but it lacks the reinforcing effect of nanofillers, so its strength is not as good as that of the complete composite material structure. The absence of additives in Comparative Example 3 means that both the base material and the filler were lost at the same time, and the strength was unsurprisingly at the lowest level, indicating that the material is prone to pulverization during daily storage, transportation, and stacking, which is not conducive to use.

[0039] By comparing and analyzing the relevant data in the table, it can be seen that the high-performance flame retardant suitable for composite materials prepared by this invention not only has good flame retardant properties but also good compressive strength. This indicates that the high-performance flame retardant suitable for composite materials provided by this invention has a broader market prospect and is more suitable for widespread application.

[0040] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-performance flame retardant suitable for composite materials, characterized in that: It includes the following raw materials in parts by weight: 45-55 parts isocyanate, 45-55 parts polyglycerol, 5-10 parts dimethyl methylphosphonate, and 2-10 parts additives. The additive is prepared by the following method: S1: Base material preparation, the raw materials of the base material include hydrogenated tallow amine polyoxyethylene ether, isopropanol, KH560, KH792 and sodium 3-chloro-2-hydroxypropyl sulfonate aqueous solution; S2: Filler preparation, the raw materials of the filler include composite powder, nano silica, expandable graphite and mixed liquid; S3: Mixing treatment, the base material and filler are mixed to obtain the additive.

2. The high-performance flame retardant suitable for composite materials according to claim 1, characterized in that, The method for preparing the base material is as follows: hydrogenated tallow amine polyoxyethylene ether and isopropanol are added to a reactor, heated to 60-80℃ for 3-5 hours to dissolve, then a mixture of KH560, KH792 and isopropanol is added, mixed well, and then an aqueous solution of sodium 3-chloro-2-hydroxypropyl sulfonate is added. The temperature is set to 70-80℃, and the mixture is stirred and reacted for 4-5 hours. The isopropanol and water are evaporated to dryness under normal pressure to obtain the base material.

3. The high-performance flame retardant suitable for composite materials according to claim 2, characterized in that, The mass ratio of hydrogenated tallow amine polyoxyethylene ether to isopropanol is 1:2-3; the molar ratio of hydrogenated tallow amine polyoxyethylene ether, KH560, KH792 and sodium 3-chloro-2-hydroxypropyl sulfonate is 1:0.7-0.8:0.2-0.3:1-1.2; the mass fraction of the aqueous solution of sodium 3-chloro-2-hydroxypropyl sulfonate is 28-38%; and the amount of isopropanol added to the mixture of KH560, KH792 and isopropanol is 60-80% of the total mass of KH560 and KH792.

4. The high-performance flame retardant suitable for composite materials according to claim 1, characterized in that, The filler is prepared by adding composite powder, nano-silica and expandable graphite into a mixer, stirring at 80-100 rpm for 20-30 minutes, then adding a mixed liquid, and stirring at 100-200 rpm for 40-60 minutes to obtain the filler.

5. The high-performance flame retardant suitable for composite materials according to claim 4, characterized in that, The mass ratio of composite powder, nano-silica, and expandable graphite is 1:0.2-0.3:0.15-0.25, and the mass of the mixture is 10-15% of the mass of the composite powder.

6. The high-performance flame retardant suitable for composite materials according to claim 4, characterized in that, The composite powder is prepared by mixing aluminum hydroxide and magnesium hydroxide, and the mixture is prepared by mixing KH570 and anhydrous ethanol, wherein the mass ratio of aluminum hydroxide to magnesium hydroxide is 1:1-2, and the mass ratio of KH570 to anhydrous ethanol is 1:

1.

7. The high-performance flame retardant suitable for composite materials according to claim 1, characterized in that, The mixing process is as follows: the base material is put into a mixer and heated to 75-85℃. The mixture is stirred at 20-40 rpm for 20-30 minutes. Then, the filler is added in three batches. The first batch contains 50% of the total mass. After mixing evenly, the second batch contains 25% of the total mass. After mixing evenly, the third batch contains another 25% of the total mass. During the addition of the filler, the stirring speed is gradually adjusted to 300-500 rpm. After the filler is added, the stirring speed is increased to 800-1000 rpm. The temperature is maintained at 75-85℃, and the mixture is stirred for 60-80 minutes. After the product is cooled to room temperature, it is pulverized to complete the mixing process and obtain the additive.

8. The high-performance flame retardant suitable for composite materials according to claim 1, characterized in that, The isocyanate is selected from at least one of hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-diphenylmethane diisocyanate.

9. The high-performance flame retardant suitable for composite materials according to claim 1, characterized in that, The average molecular weight of the polypropylene triol is 3000-5000, and the hydroxyl value is 100-120 mgKOH / g.

10. The method for preparing a high-performance flame retardant suitable for composite materials according to any one of claims 1-9, characterized in that, Includes the following steps: Under dry nitrogen protection, isocyanate and polypropylene triol are added to a reactor and stirred at 300-500 rpm for 2-3 hours at 60-70℃. Then, the temperature is lowered to 40-50℃, dimethyl methylphosphonate is added first, and the mixture is stirred for 10-15 minutes. Then, additives are added, and the mixture is stirred for 30-60 minutes under a vacuum of -0.08 MPa. After that, the vacuum is released, the mixture is discharged under nitrogen protection, sealed and packaged to obtain a high-performance flame retardant suitable for composite materials.

Images