MXene multi-element nano composite antiknock flame-retardant coating and coating

Abstract

The invention provides an MXene multi-element nano-composite antiknock flame-retardant coating and a coating, and relates to the technical field of flame retardance and antiknock. An MXene multi-element nano-composite antiknock elastomer is added into a component B as a reactive flame retardant, and the reactive flame retardant is introduced into a molecular chain of a high-molecular elastomer material to realize intrinsic flame retardance; flame-retardant elements are connected in a high-molecular polymer network in the form of chemical bonds, so that the flame-retardant elements are difficult to migrate and seep, and the flame-retardant capability is more efficient and lasting; secondly, a secondary doping method is adopted, the dispersity of a two-dimensional lamellar material is improved, the interfacial compatibility between the materials is enhanced, the morphology of a product is improved, the flame retardant property of the MXene multi-element nano composite anti-explosion elastomer is improved, a template is provided for growth of a polymer skeleton through polymerization of carbon nano onion, graphene and MXene modified polyaniline nanofiber materials, and the flame retardant property of the MXene multi-element nano composite anti-explosion elastomer is improved. A compact net-shaped structure is formed, and the problems that a reactive flame retardant is poor in compatibility, easy to agglomerate and not easy to apply in a matrix material are solved.

Description

Technical Field

[0001] This invention relates to the technical field of flame-retardant and explosion-proof functional materials, and in particular to an MXene multi-component nanocomposite explosion-proof and flame-retardant coating and coating layer. Background Technology

[0002] Explosion-resistant materials, as a class of special materials with high impact strength, high toughness, and explosion-proof protection functions, are widely used in military protection, building safety, transportation, and other fields. Traditional explosion-resistant materials mainly use polymer materials such as polyurethane, epoxy resin, and polyamide as base materials. Although they have certain impact resistance, these materials generally have problems such as flammability, high smoke toxicity during combustion, and high heat release rate, which seriously limits their application in high-safety-requirement scenarios.

[0003] To address the flame retardancy issue of explosion-proof materials, existing technologies primarily employ modification by adding flame retardants. Common flame retardants include halogenated, phosphorus-based, and inorganic flame retardants. However, these methods have significant technical drawbacks: halogenated flame retardants produce large amounts of toxic and harmful gases during combustion, posing serious threats to the environment and human health, and their use has been gradually restricted; phosphorus-based flame retardants have low flame retardant efficiency, requiring a high proportion to achieve the desired effect, leading to a significant decrease in the material's mechanical properties; the addition of inorganic flame retardants (such as magnesium hydroxide and aluminum hydroxide) typically exceeds 50%, affecting not only the material's processing fluidity but also causing a substantial reduction in key properties such as impact strength and flexibility. Therefore, developing an explosion-proof material that combines high flame retardancy with excellent mechanical properties has become a current research hotspot and urgent need in this field.

[0004] MXene, as a novel type of two-dimensional layered nanomaterial, exhibits great application potential in the field of flame retardancy due to its unique layered structure, high specific surface area, excellent thermal and electrical conductivity, and catalytic properties. The layered structure of MXene can form a physical barrier layer during combustion, preventing the transfer of heat and oxygen; its surface functional groups can interact with polymer substrates, enhancing interfacial bonding; simultaneously, MXene can catalyze the char formation reaction of polymer materials, forming a dense char layer that further inhibits flame spread. However, the flame retardant effect of single MXene is limited, and MXene nanosheets are prone to agglomeration in polymer substrates, making it difficult for the material's mechanical and flame retardant properties to meet practical application requirements.

[0005] Polyaniline (PANI), as a conductive polymer material, possesses excellent char-forming properties, environmental stability, and flame-retardant synergy. The amino and quinone groups in its molecular structure can capture free radicals during combustion, inhibiting the combustion chain reaction. Simultaneously, PANI can synergistically interact with MXene, improving the dispersibility of nanofillers in the substrate. Carbon nano-onions (CNOs), spherical nanomaterials composed of multiple graphite shells, possess high specific surface area, high thermal conductivity, and excellent mechanical properties, and can act as flame-retardant synergists to enhance the density and stability of the char layer. Graphene (RGO), as a representative of two-dimensional carbon materials, has extremely high mechanical strength and thermal conductivity. Its layered structure can complement MXene, further optimizing the physical barrier effect. However, there are currently no reports on the synergistic composite of MXene, polyaniline, carbon nano-onions, and graphene into explosion-proof substrates to simultaneously improve the material's flame-retardant and mechanical properties.

[0006] In the development of composite materials, binary composite systems (such as carbon nanotube onion / polyaniline) have been successfully prepared, but research on ternary and quaternary nanocomposites is still relatively scarce. Furthermore, existing multi-component composite materials generally suffer from complex preparation processes, uneven dispersion of components, and insignificant synergistic effects. At the same time, different nanocomponents (such as MXene, carbon nanotube onion, graphene, and polyaniline) exhibit significant differences in surface properties and poor interfacial compatibility, easily agglomerating due to van der Waals forces. This makes it difficult to prepare composite materials with regular morphology and excellent performance through direct in-situ polymerization, which has become a key technical bottleneck in the preparation of multi-component composite anti-corrosion materials. Summary of the Invention

[0007] This invention provides an MXene multi-component nanocomposite explosion-proof and flame-retardant coating and coating, which aims to significantly improve the flame-retardant performance, mechanical strength and explosion-proof stability of the material by constructing a quaternary nanocomposite system of "MXene / carbon nano-onion / graphene / polyaniline" and utilizing the synergistic flame-retardant effect of the multi-components and interface optimization design. At the same time, it adopts a green and environmentally friendly preparation process to reduce production costs and meet the needs of practical applications.

[0008] On one hand, the present invention provides an MXene multi-component nanocomposite explosion-proof and flame-retardant coating, wherein the MXene multi-component nanocomposite explosion-proof and flame-retardant coating comprises independently packaged components A and B, wherein component A comprises hydroxyl-terminated polyether and isocyanate MDI-50 in a mass ratio of 1:8~20, and component B comprises amino-terminated polyether, MXene multi-functional nanocomposite explosion-proof elastomer, and chain extender in a mass ratio of 40~80:10~20:15~25, wherein the MXene multi-functional nanocomposite explosion-proof elastomer is composed of carbon nanotube onion, graphene, MXene and polyaniline through primary doping, dedoping and secondary doping.

[0009] Optionally, the mass ratio of carbon nanotubes, graphene, and MXene in the MXene multifunctional nanocomposite explosion-proof elastomer is 2~4:1~3:1.

[0010] Optionally, the mass ratio of carbon nanotubes, graphene, and MXene in the MXene multifunctional nanocomposite explosion-proof elastomer is 3:2:1.

[0011] Optionally, the MXene multifunctional nanocomposite explosion-proof elastomer contains carbon nanoparticles, graphene, and MXene-modified secondary doped polyaniline compounds.

[0012] Optionally, the MXene multi-component nanocomposite explosion-proof and flame-retardant coating has a corrosion inhibition efficiency greater than 80% and an impedance value greater than 1800 Ω·cm. 2 .

[0013] Optionally, the MXene multifunctional nanocomposite explosion-proof elastomer is composed of carbon nanotube onion, graphene, MXene and aniline in H2SO4 solution in combination with ammonium persulfate and ammonia water through primary doping, dedoping and secondary doping.

[0014] Optionally, the MXene multifunctional nanocomposite explosion-proof elastomer is prepared using the following method: I) Preparation of MXene precursor (11) Take 30 mL of H2SO4 solution with a concentration of 6 mol / L, then add 98% pure LiF to the H2SO4 solution and stir with a magnetic Teflon stir bar for 4~10 min to ensure that the LiF is completely dissolved. (12) Slowly add Ti3AlC2 powder to the above mixed solution, control the temperature of the reaction system at 30~40℃, and react at a constant temperature for 20~24 h; (13) After the reaction is complete, distilled water is added to the system and the product is washed 5 times by centrifugation-decantation until the pH of the supernatant reaches 6. Finally, the MXene precursor is obtained by centrifugation and filtration. II) Preparation of primary doped polyaniline-based composite materials (21) Take two 20 mL H2SO4 solutions with a concentration of 1 mol / L as doping acid solutions. Add aniline monomer to one of the solutions and ammonium persulfate to the other. Stir each solution evenly with a magnetic stirrer. Then mix the two solutions and continue stirring with a magnetic stirrer for 2-3 h. Then let stand for 24 h to carry out the polymerization reaction. (22) After the reaction is complete, the product is washed multiple times by alternating centrifugation with ethanol and deionized water until the washing solution is neutral. The lower precipitate is collected to obtain the one-doped polyaniline preparation system. (23) Fix the amount of aniline monomer, add carbon nano onion to the above-mentioned primary doped PANI preparation system according to the mass ratio of aniline to carbon nano onion 1:5~25, repeat the operation of steps (21)~(22) to obtain carbon nano onion / primary doped PANI composite material; (24) Replace carbon nanotube onions with graphene and MXene precursors respectively, keep other experimental conditions unchanged, repeat the above preparation steps (21)~23, and obtain graphene / first-doped PANI composite material and MXene / first-doped PANI composite material in turn. III) Preparation of intrinsic polyaniline-based composite materials (31) Add excess ammonia to carbon nano onion / first-doped PANI composite material, stir with a magnetic stirrer for 1-2 h, and then let stand at room temperature for 24 h to carry out dedoping reaction; (32) After the dedoping is completed, the product is washed with ethanol and deionized water alternately until the washing solution is neutral. After drying and grinding, carbon nanoparticle onion / intrinsic polyaniline composite material is obtained. (33) Replace the carbon nanotube onion / first-doped PANI composite material with graphene / first-doped PANI composite material and MXene / first-doped PANI composite material respectively. Keep other experimental conditions unchanged, repeat the dedoping, washing, drying and grinding operations in steps (31)~(32) to obtain the graphene / EB-PANI intrinsic state composite material and MXene / EB-PANI intrinsic state composite material respectively. IV) Final Preparation of MXene Multifunctional Nanocomposite Blast-Resistant Elastomer (41) Mix the carbon nanotube onion / EB-PANI intrinsic state composite material, graphene / EB-PANI intrinsic state composite material and MXene / EB-PANI intrinsic state composite material in a predetermined mass ratio evenly, and add them to a 1 mol / L H2SO4 solution; (42) The above mixture was subjected to ultrasonic treatment, and then stirred with a magnetic stirrer for 2-3 h to ensure that each component was fully dispersed and a secondary doping reaction occurred. After that, it was allowed to stand for 24 h. (43) After the secondary doping reaction is completed, the product is washed until neutral, and then centrifuged, dried and ground to finally prepare the MXene multifunctional nanocomposite explosion-proof elastomer, which is a carbon nanotube onion-graphene-MXene-secondary doped polyaniline quaternary functional composite.

[0015] Optionally, component A is prepared using the following method: (1) The hydroxyl-terminated polyether and isocyanate MDI-50 are in a mass ratio of 1:8~20. The hydroxyl-terminated polyether is added to the reactor for dehydration. The temperature is raised to 105℃ within 30 minutes. Then the vacuum system is turned on and the temperature is raised to 110℃. The temperature is maintained at 115±3℃ and the vacuum degree is maintained above 0.075MPa. The vacuum dehydration is carried out for more than 2 hours. (2) Close the vacuum system and open the vent valve, purge with nitrogen to restore atmospheric pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the dehydration process until the polyether moisture content is lower than 0.5‰. When the polyether moisture content is lower than 0.5‰, close the vacuum system and open the vent valve, purge with nitrogen to restore atmospheric pressure, and cool to a material temperature of <60℃ to obtain the dehydrated hydroxyl-terminated polyether. (3) Turn on the stirrer and heating device. Add MDI-50 isocyanate to the dehydrated hydroxyl-terminated polyether according to the mass ratio of hydroxyl-terminated polyether to isocyanate MDI-50 of 1:8~20. Control the feeding speed and add slowly and evenly within 30 minutes. The feeding should be completed before the material temperature rises to 60℃. (4) After the material is added, control the temperature to rise to 75°C within 20 minutes, and keep the temperature at 75±2°C for 2 hours; then raise the temperature to 82°C within 10 minutes, and keep the temperature at 82±2°C for 2 hours. During the reaction, strictly control the material temperature not to exceed 86°C. (5) After the reaction is complete, stop heating and turn on the cooling device. Control the cooling rate to reduce the material temperature to below 60°C within 20 minutes. Continue stirring for 30 minutes. Then filter with a 100-mesh copper mesh and fill the container. After filling, nitrogen must be filled into the packaging container to ensure that the packaging container is sealed properly and obtain the A component in an independently sealed package.

[0016] Optionally, component B is prepared using the following method: (1) According to the mass ratio of terminal amino polyether, MXene multi-component nanocomposite explosion-proof elastomer and chain extender of 40~80:10~20:15~25, first add terminal amino polyether and MXene multi-component nanocomposite explosion-proof elastomer for mixing, turn on the stirrer and heating device, then add chain extender, control the temperature to rise to 105℃ within 30min, turn on the vacuum system, continue to heat up to 110℃, maintain the temperature at 110±3℃, maintain the vacuum degree above 0.075MPa, and vacuum dehydrate for more than 2h; (2) Close the vacuum system and open the vent valve, fill with nitrogen to restore normal pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the vacuum dehydration operation until the moisture content is lower than 0.5‰. (3) After the moisture content is lower than 0.5‰, the vacuum system is turned off and the vent valve is opened. Nitrogen gas is added to restore the pressure to normal. Then, the ground pigment titanium dioxide and filler mica iron oxide are added to the reactor and stirred at high speed for 1 hour. (4) Turn on the vacuum system, maintain the vacuum degree at 0.075MPa, keep the temperature at 80±2℃, degas for 15min, turn off the vacuum system and heating device, stir at low speed, then fill with nitrogen to remove the vacuum, cool to the material temperature <60℃, filter with a 100-mesh copper mesh and fill. After filling, nitrogen must be filled into the packaging barrel for protection to ensure that the packaging container is sealed and the B component is individually sealed.

[0017] On the other hand, the present invention also provides an MXene multi-component nanocomposite explosion-proof and flame-retardant coating prepared using the above-mentioned MXene multi-component nanocomposite explosion-proof and flame-retardant coating, characterized in that components A and B, which are packaged independently, are mixed in a volume ratio of 1:1, and then coated onto the surface of a substrate by spraying, brushing or scraping. After curing at room temperature, an MXene multi-component nanocomposite explosion-proof and flame-retardant coating with a thickness of 200~400μm is formed. The substrate is a metal, plastic or ceramic material.

[0018] The present invention has the following beneficial technical effects: This invention provides an MXene multi-component nanocomposite explosion-proof and flame-retardant coating and coating layer. MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer is added to component B as a reactive flame retardant. Utilizing the chemical reaction between the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer and the terminal amino polyether in component B, the reactive flame retardant is introduced into the molecular chain of the polymer elastomer material to achieve intrinsic flame retardancy. The flame-retardant elements are linked in the polymer network in the form of chemical bonds, making it difficult for the flame-retardant elements to migrate and leach out, resulting in more efficient and durable flame retardant capabilities. Secondly, HF etching is used to obtain a surface rich in P / N elements. Reactive MXene is used to participate in aniline polymerization in situ, acting as both a flame retardant and a micro-crosslinking agent to form a tightly bonded interface. Furthermore, a secondary doping method is employed to improve the dispersibility of the two-dimensional sheet material, enhance the interfacial compatibility between materials, and improve the product morphology, thereby enhancing the flame retardant properties of the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer. By modifying polyaniline nanofiber materials with carbon nanoparticles, graphene, and MXene, a template is provided for the growth of the polymer skeleton, forming a dense network structure. This solves the problems of poor compatibility, easy agglomeration, and difficulty in application of reactive flame retardants in matrix materials. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 Scanning electron microscope (SEM) comparison images of different product morphologies provided in the embodiments of this application.

[0021] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] To address the technical problems existing in the prior art, this application provides an MXene multi-component nanocomposite explosion-proof and flame-retardant coating. MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer is added to component B as a reactive flame retardant. Utilizing the chemical reaction between the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer and the terminal amino polyether in component B, the reactive flame retardant is introduced into the molecular chain of the polymer elastomer material to achieve intrinsic flame retardancy. The flame-retardant elements are connected in the form of chemical bonds in the polymer network, making it difficult for the flame-retardant elements to migrate and leach out, resulting in more efficient and durable flame retardancy. Hydrofluoric acid etching is used to obtain a reactive MXene precursor with a surface rich in P / N elements, allowing it to participate in aniline polymerization in situ, forming a tightly bonded interface. A primary doping, dedoping, and secondary doping method is employed, through a modification strategy, to achieve a synergistic effect of the anti-corrosion effects of various two-dimensional sheet nanomaterials, solving problems such as easy agglomeration, short fiber length, and poor film density during in-situ polymerization of polyaniline. Two-dimensional sheet nanomaterials such as carbon nanotubes, graphene, and MXene precursors were surface-modified with polyaniline to expand the interlayer spacing and enhance their stability and dispersibility. This tightly and organically combined multiple materials such as carbon nanotubes, polyaniline, graphene, and MXene precursors at the nanoscale, improving the dispersibility and product morphology of the two-dimensional sheet nanomaterials and forming a three-dimensional network structure. This enhanced the anti-corrosion performance of MXene (Ti3AlC2) multi-component nanocomposite anti-corrosion coatings. Furthermore, the polymerization of polyaniline nanofibers modified with carbon nanotubes, graphene, and MXene provided a template for polymer skeleton growth, forming a dense network structure. This solved the problems of poor compatibility, easy agglomeration, and difficulty in application in the matrix material.

[0024] Based on the above-mentioned inventive concept, the present invention provides an MXene multi-component nanocomposite explosion-proof and flame-retardant coating comprising independently packaged components A and B. Component A comprises hydroxyl-terminated polyether and isocyanate MDI-50 in a mass ratio of 1:8~20. Component B comprises amino-terminated polyether, MXene multi-functional nanocomposite explosion-proof elastomer, and chain extender in a mass ratio of 40~80:10~20:15~25. The MXene multi-functional nanocomposite explosion-proof elastomer used is composed of carbon nanotubes, graphene, MXene, and polyaniline through primary doping, dedoping, and secondary doping.

[0025] The mass ratio of carbon nanotubes (onion), graphene, and MXene in the MXene multifunctional nanocomposite explosion-proof elastomer is 2-4:1-3:1. Preferably, the mass ratio of carbon nanotubes (onion), graphene, and MXene in the MXene multifunctional nanocomposite explosion-proof elastomer is 3:2:1, and the MXene multifunctional nanocomposite explosion-proof elastomer prepared under this ratio has the best anti-corrosion performance.

[0026] The MXene multifunctional nanocomposite explosion-proof elastomer used in this invention contains carbon nanotubes, graphene, and MXene-modified secondary-doped polyaniline compounds. Component A has an NCO mass fraction of 18% and an isocyanate index of 1-1.2. Optionally, component B also includes pigment titanium dioxide and filler mica iron oxide; the molecular weight of the terminal amino polyether in component B is 1000-8000. The MXene multifunctional nanocomposite explosion-proof elastomer is synthesized by primary doping, dedoping, and secondary doping of carbon nanotubes, graphene, MXene, and polyaniline in H2SO4 solution in combination with ammonium persulfate and ammonia.

[0027] Specifically, the MXene multifunctional nanocomposite explosion-proof elastomer used in this invention is prepared by the following method: I) Preparation of MXene precursor (11) Take 30 mL of H2SO4 solution with a concentration of 6 mol / L, then add 98% pure LiF to the H2SO4 solution and stir with a magnetic Teflon stir bar for 4~10 min to ensure that the LiF is completely dissolved. (12) Slowly add Ti3AlC2 powder to the above mixed solution, control the temperature of the reaction system at 30~40℃, and react at a constant temperature for 20~24 h; (13) After the reaction is complete, distilled water is added to the system and the product is washed 5 times by centrifugation-decantation until the pH of the supernatant reaches 6. Finally, the MXene precursor is obtained by centrifugation and filtration.

[0028] A reactive MXene precursor rich in P / N active elements was prepared by hydrofluoric acid etching, which promoted its in-situ participation in the aniline polymerization reaction and formed a tightly connected interface structure with covalent bonds. By using secondary doping technology and targeted modification strategies, the anti-corrosion performance of various two-dimensional sheet nanomaterials was synergistically enhanced, and the technical problems of easy agglomeration, short fiber size and insufficient film density in the in-situ polymerization of polyaniline were successfully solved.

[0029] II) Preparation of primary doped polyaniline-based composite materials (21) Take two 20 mL H2SO4 solutions with a concentration of 1 mol / L as doping acid solutions. Add aniline monomer to one of the solutions and ammonium persulfate to the other. Stir each solution evenly with a magnetic stirrer. Then mix the two solutions and continue stirring with a magnetic stirrer for 2-3 h. Then let stand for 24 h to carry out the polymerization reaction. (22) After the reaction is complete, the product is washed multiple times by alternating centrifugation with ethanol and deionized water until the washing solution is neutral. The lower precipitate is collected to obtain the one-doped polyaniline preparation system. (23) Fix the amount of aniline monomer, add carbon nano onion to the above-mentioned primary doped PANI preparation system according to the mass ratio of aniline to carbon nano onion 1:5~25, repeat the operation of steps (21)~(22) to obtain carbon nano onion / primary doped PANI composite material; (24) Replace carbon nanotube onions with graphene and MXene precursors respectively, keep other experimental conditions unchanged, and repeat the above preparation steps (21)~(23) to obtain graphene / first-doped PANI composite material and MXene / first-doped PANI composite material in turn; III) Preparation of intrinsic polyaniline-based composite materials (31) Add excess ammonia to carbon nano onion / first-doped PANI composite material, stir with a magnetic stirrer for 1-2 h, and then let stand at room temperature for 24 h to carry out dedoping reaction; (32) After the dedoping is completed, the product is washed with ethanol and deionized water alternately until the washing solution is neutral. After drying and grinding, carbon nanoparticle onion / intrinsic polyaniline composite material is obtained. (33) Replace the carbon nanotube onion / first-doped PANI composite material with graphene / first-doped PANI composite material and MXene / first-doped PANI composite material respectively. Keep other experimental conditions unchanged, repeat the dedoping, washing, drying and grinding operations in steps (31)~(32) to obtain the graphene / EB-PANI intrinsic state composite material and MXene / EB-PANI intrinsic state composite material respectively. IV) Final Preparation of MXene Multifunctional Nanocomposite Blast-Resistant Elastomer (41) Mix the carbon nanotube onion / EB-PANI intrinsic state composite material, graphene / EB-PANI intrinsic state composite material and MXene / EB-PANI intrinsic state composite material in a predetermined mass ratio evenly, and add them to a 1 mol / L H2SO4 solution; (42) The above mixture was subjected to ultrasonic treatment, and then stirred with a magnetic stirrer for 2-3 h to ensure that each component was fully dispersed and a secondary doping reaction occurred. After that, it was allowed to stand for 24 h. (43) After the secondary doping reaction is completed, the product is washed until neutral, and then centrifuged, dried and ground to finally prepare the MXene multifunctional nanocomposite explosion-proof elastomer, which is a carbon nanotube onion-graphene-MXene-secondary doped polyaniline quaternary functional composite.

[0030] The A component of the MXene multi-component nanocomposite explosion-proof and flame-retardant coating provided by this invention is prepared by the following method: (1) The hydroxyl-terminated polyether and isocyanate MDI-50 are in a mass ratio of 1:8~20. The hydroxyl-terminated polyether is added to the reactor for dehydration. The temperature is raised to 105℃ within 30 minutes. Then the vacuum system is turned on and the temperature is raised to 110℃. The temperature is maintained at 115±3℃ and the vacuum degree is maintained above 0.075MPa. The vacuum dehydration is carried out for more than 2 hours. (2) Close the vacuum system and open the vent valve, purge with nitrogen to restore atmospheric pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the dehydration process until the polyether moisture content is lower than 0.5‰. When the polyether moisture content is lower than 0.5‰, close the vacuum system and open the vent valve, purge with nitrogen to restore atmospheric pressure, and cool to a material temperature of <60℃ to obtain the dehydrated hydroxyl-terminated polyether. (3) Turn on the stirrer and heating device. Add MDI-50 isocyanate to the dehydrated hydroxyl-terminated polyether according to the mass ratio of hydroxyl-terminated polyether to isocyanate MDI-50 of 1:8~20. Control the feeding speed and add slowly and evenly within 30 minutes. The feeding should be completed before the material temperature rises to 60℃. (4) After the material is added, control the temperature to rise to 75°C within 20 minutes, and keep the temperature at 75±2°C for 2 hours; then raise the temperature to 82°C within 10 minutes, and keep the temperature at 82±2°C for 2 hours. During the reaction, strictly control the material temperature not to exceed 86°C. (5) After the reaction is complete, stop heating and turn on the cooling device. Control the cooling rate to reduce the material temperature to below 60°C within 20 minutes. Continue stirring for 30 minutes. Then filter with a 100-mesh copper mesh and fill the container. After filling, nitrogen must be filled into the packaging container to ensure that the packaging container is sealed. Component A of the MXene multi-component nanocomposite explosion-proof and flame-retardant coating is obtained in an independently sealed package.

[0031] The B component of the MXene multi-component nanocomposite explosion-proof and flame-retardant coating provided by this invention is prepared by the following method: (1) According to the mass ratio of terminal amino polyether, MXene multi-component nanocomposite explosion-proof elastomer and chain extender of 40~80:10~20:15~25, first add terminal amino polyether and MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer for mixing. After turning on the stirrer and heating device, add the chain extender. When the temperature reaches 105℃ within 30 minutes, turn on the vacuum system and continue to heat up to 110℃. Maintain the temperature at 110±3℃ and maintain the vacuum degree above 0.075MPa. Vacuum dehydration for more than 2 hours. (2) Close the vacuum system and open the vent valve, fill with nitrogen to restore normal pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the vacuum dehydration operation until the moisture content is lower than 0.5‰. (3) After the moisture content is lower than 0.5‰, the vacuum system is turned off and the vent valve is opened. Nitrogen gas is added to restore the pressure to normal. Then, the ground pigment titanium dioxide and filler mica iron oxide are added to the reactor and stirred at high speed for 1 hour. (4) Turn on the vacuum system, maintain the vacuum degree at 0.075MPa, keep the temperature at 80±2℃, degas for 15min, turn off the vacuum system and heating device, stir at low speed, then fill with nitrogen to remove the vacuum, cool to the material temperature <60℃, filter with a 100-mesh copper mesh and fill. After filling, the packaging barrel must be filled with nitrogen for protection to ensure the packaging container is sealed. The B component of the MXene multi-element nano-composite explosion-proof and flame-retardant coating is individually sealed.

[0032] This application provides a method for preparing MXene (Ti3AlC2) multi-component nanocomposite anti-corrosion coatings and their applications. MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer is added to component B of the coating as a reactive flame retardant. The reactive flame retardant is introduced into the molecular chain of the polymer elastomer material through a chemical reaction between the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer and the terminal amino polyether in component B, achieving intrinsic flame retardancy. The flame-retardant elements are linked in the polymer network by chemical bonds, making it difficult for them to migrate and leach out, resulting in more efficient and durable flame retardancy. Secondly, reactive MXene with P / N element-rich surface was obtained by HF etching, allowing it to participate in aniline polymerization in situ. Simultaneously, it served as a flame retardant and micro-crosslinking agent, forming a tightly bonded interface. Furthermore, a secondary doping method was employed to improve the dispersibility of the two-dimensional sheet material, enhance interfacial compatibility, and improve the product morphology, thereby enhancing the flame retardant properties of the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer. The polymerization of polyaniline nanofibers modified with carbon nanoparticles, graphene, and MXene provided a template for polymer skeleton growth, forming a dense network structure. This solved the problems of poor compatibility, easy agglomeration, and difficulty in application of reactive flame retardants in matrix materials.

[0033] Polyaniline (PANI), a typical conductive polymer, possesses good environmental stability, reversible redox properties, and excellent corrosion resistance. Graphene (RGO), as a single layer of carbon atoms in spline form... 2Two-dimensional materials with hybrid structures possess excellent physical barrier properties and chemical inertness. MXenes, as a novel class of two-dimensional transition metal carbides, nitrides, or carbonitrides, exhibit high electrical conductivity, abundant surface functional groups, and excellent hydrophilicity. Carbon nano-onions (CNOs), as carbon molecules with a concentric multilayer spherical stacked structure centered on C60, possess unique nanostructure and surface properties. The dispersion of graphene in a polymer matrix is ​​crucial for achieving its superior performance; however, due to the strong π-π interactions and van der Waals forces between graphene sheets, irreversible aggregation easily occurs, leading to uneven dispersion in the polymer matrix. Therefore, an in-situ polymerization method is employed to polymerize the monomers in the presence of graphene, allowing polyaniline to grow on the graphene surface, achieving molecular-level dispersion of graphene while simultaneously forming strong interfacial interactions between graphene and the polymer. In polymer matrices, carbon nanotubes, due to their large surface curvature, can adsorb onto the edges and defects of other nanomaterials, preventing their aggregation. Carbon nanotubes can act as dispersants to help other nanomaterials (especially graphene) achieve uniform dispersion.

[0034] Graphene and MXene, as two-dimensional sheet materials, form a sheet structure parallel to the substrate surface in the coating, constituting the first physical barrier. Graphene sheets can extend the diffusion path of corrosive media by 10-100 times, while MXene sheets, due to their larger interlayer spacing and surface functional groups, can provide additional barrier effects. Carbon nanoparticles fill the gaps between graphene and MXene sheets, forming a second barrier. Their spherical structure not only effectively fills the pores but also acts as a "ball bearing," reducing friction between sheets and facilitating their orientation. Simultaneously, the large surface curvature of carbon nanoparticles allows them to adsorb onto the edges and defects of the sheets, further enhancing the barrier effect. Polyaniline, as the continuous phase, binds the other three materials together, forming a continuous three-dimensional network structure. The extended polyaniline molecular chains after secondary doping can better coat the surfaces of other materials, filling surface defects and forming a denser composite structure.

[0035] Single-material coatings inevitably contain defects, such as the edges of graphene, surface defects in MXene, and gaps in carbon nanotubes. The synergistic effect of quaternary composite materials can achieve mutual compensation of defects. Carbon nanotubes can fill the gaps between graphene sheets, and polyaniline can coat the surface of all two-dimensional nanomaterials to form a seamless protective layer. This invention utilizes polyaniline to modify the surfaces of two-dimensional sheet nanomaterials such as carbon nanotubes, graphene, and MXene precursors, effectively expanding the interlayer distance and improving their structural stability and dispersion performance. This achieves a tight organic composite of quaternary components—carbon nanotubes, MXene, graphene, and polyaniline—at the nanoscale, effectively improving the dispersion state of the two-dimensional sheet materials and the microstructure of the composite product. It also enhances the flame-retardant and explosion-proof performance of MXene multi-component nanocomposite anti-explosion and flame-retardant coatings. Furthermore, the polymerization of secondary-doped polyaniline nanofibers modified with carbon nanotubes, graphene, and MXene provides a template for polymer skeleton growth, forming a dense network structure. This solves the problems of poor compatibility, easy agglomeration, and difficulty in application in matrix materials, successfully overcoming technical challenges such as easy agglomeration, short fiber size, and insufficient film density during the in-situ polymerization of polyaniline. A three-dimensional interwoven network structure is formed, constructing a more uniform and dense composite system, ultimately developing a quaternary nanocomposite material with multiple protection mechanisms and superior flame-retardant and explosion-proof performance.

[0036] The technical solution of this application will now be described in detail through specific embodiments. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0037] Example 1: This application provides an MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating comprising independently packaged components A and B. Component A comprises hydroxyl-terminated polyether T-5000 and isocyanate MDI-50 in a mass ratio of 1:8~20. Component B comprises amino-terminated polyether T-5000, MXene multi-functional nanocomposite explosion-proof elastomer, and chain extender in a mass ratio of 40~80:10~20:15~25. The MXene multi-functional nanocomposite explosion-proof elastomer used is composed of carbon nanotubes, graphene, MXene, and polyaniline through primary doping, dedoping, and secondary doping.

[0038] The MXene (Ti3AlC2) multi-component nanocomposite blast-resistant elastomer used in this application embodiment is synthesized by primary doping, dedoping, and secondary doping of carbon nanotubes, graphene, MXene, and aniline in a mass ratio of 1:5~25 in H2SO4 solution with ammonium persulfate and ammonia. The molecular structure of the MXene blast-resistant elastomer contains a two-dimensional lamellar structure, high specific surface area, and abundant surface functional groups. The MXene (Ti3AlC2) multi-component nanocomposite blast-resistant elastomer contains a secondary-doped polyaniline-MXene compound modified with carbon nanotubes and graphene.

[0039] This application provides an MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating, wherein the NCO mass fraction of component A is 18%, and the isocyanate index of component A is 1~1.2. Preferably, the isocyanate index of component A is 1.08. NCO refers to the isocyanate group in the chemical material, and the NCO mass fraction refers to the mass of isocyanate (-NCO) groups contained in 100g of sample. When the NCO mass fraction of component A is 18% and the isocyanate index of component A is 1.08, the flame-retardant and explosion-proof effect is best when component A is mixed with component B.

[0040] Furthermore, component B in this application embodiment also includes pigment titanium dioxide and filler mica iron oxide, and the molecular weight of the amino-terminated polyether used in component B is 1000~8000.

[0041] Example 2: This application provides a method for preparing the above-mentioned MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating. The MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating includes independently packaged component A and component B. Component A and component B are mixed in a 1:1 volume ratio to form the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating. The preparation method of component A includes: (1) The hydroxyl-terminated polyether and isocyanate MDI-50 are in a mass ratio of 1:8~20. The hydroxyl-terminated polyether is added to the reactor for dehydration. The temperature is raised to 105℃ within 30 minutes. Then the vacuum system is turned on and the temperature is raised to 110℃. The temperature is maintained at 115±3℃ and the vacuum degree is maintained above 0.075MPa. The vacuum dehydration is carried out for more than 2 hours. (2) Close the vacuum system and open the vent valve, purge with nitrogen to restore atmospheric pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the dehydration process until the polyether moisture content is lower than 0.5‰. When the polyether moisture content is lower than 0.5‰, close the vacuum system and open the vent valve, purge with nitrogen to restore atmospheric pressure, and cool to a material temperature of <60℃ to obtain the dehydrated hydroxyl-terminated polyether. (3) Turn on the stirrer and heating device. Add MDI-50 isocyanate to the dehydrated hydroxyl-terminated polyether according to the mass ratio of hydroxyl-terminated polyether to isocyanate MDI-50 of 1:8~20. Control the feeding speed and add slowly and evenly within 30 minutes. The feeding should be completed before the material temperature rises to 60℃. (4) After the material is added, control the temperature to rise to 75°C within 20 minutes, and keep the temperature at 75±2°C for 2 hours; then raise the temperature to 82°C within 10 minutes, and keep the temperature at 82±2°C for 2 hours. During the reaction, strictly control the material temperature not to exceed 86°C. (5) After the reaction is complete, stop heating and turn on the cooling device. Control the cooling rate to reduce the material temperature to below 60°C within 20 minutes. Continue stirring for 30 minutes. Then filter with a 100-mesh copper mesh and fill the container. After filling, nitrogen must be filled into the packaging container to ensure that the packaging container is sealed properly and obtain the A component in an independently sealed package.

[0042] During the preparation of component A, the reaction process is strictly controlled by stepwise heating and temperature maintenance. This prevents the isocyanate in component A from undergoing accelerated self-polymerization due to excessively high temperatures, avoids excessive NCO consumption, effectively maintains the NCO content in the system, and ensures product performance. At the same time, the strict control of stepwise heating and temperature maintenance during the reaction process effectively prevents the reaction from failing to reach the reaction endpoint for an extended period due to excessively low temperatures. This avoids the presence of a large amount of unreacted hydroxyl groups and NCO in the system, effectively ensuring the flame-retardant and explosion-proof properties of component A.

[0043] The preparation methods for component B include: (1) According to the mass ratio of terminal amino polyether T-5000, MXene (Ti3AlC2) multi-element nanocomposite explosion-proof elastomer and chain extender E-100 of 40~80:10~20:15~25, first add terminal amino polyether T-5000 and MXene (Ti3AlC2) multi-element nanocomposite explosion-proof elastomer for mixing. After turning on the stirrer and heating device, add chain extender E-100. When the temperature reaches 105℃ within 30min, turn on the vacuum system and continue to heat up to 110℃. Maintain the temperature at 110±3℃ and the vacuum degree at more than 0.075MPa. Vacuum dehydration for more than 2h. (2) Close the vacuum system and open the vent valve, fill with nitrogen to restore normal pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the vacuum dehydration operation until the moisture content is lower than 0.5‰. (3) After the moisture content is lower than 0.5‰, the vacuum system is turned off and the vent valve is opened. Nitrogen gas is added to restore the pressure to normal. Then, the ground pigment titanium dioxide and filler mica iron oxide are added to the reactor and stirred at high speed for 1 hour. (4) Turn on the vacuum system, maintain the vacuum degree at 0.075MPa, keep the temperature at 80±2℃, degas for 15min, turn off the vacuum system and heating device, stir at low speed, then fill with nitrogen to remove the vacuum, cool to the material temperature <60℃, filter with a 100-mesh copper mesh and fill. After filling, nitrogen must be filled into the packaging barrel for protection to ensure that the packaging container is sealed and the B component is individually sealed.

[0044] In the preparation of component B, a process is adopted in which high molecular weight amino polyether is first mixed with flame retardant MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer, and then low molecular weight chain extender E-100 (polyether polyamine) is added. This process effectively avoids the problem of amine value reduction caused by the volatilization loss of low molecular weight polyether polyamine, and greatly increases the stability of the system and the flame retardant and explosion-proof performance of the component.

[0045] The preparation methods of MXene (Ti3AlC2) multi-component nanocomposite anti-explosion elastomer include: (1) Prepare 30 mL of 6M H2SO4 solution by adding concentrated H2SO4 (Fisher, technical grade) to distilled water. Add LiF (Alfa Aesar, 98% purity) and stir the mixture for 5 min with a magnetic Teflon stir bar to dissolve. Slowly add Ti3AlC2 powder and keep the reaction mixture at 35°C for 24 h. Add distilled water, centrifuge, decant, and cycle 5 times to wash the mixture until the pH of the supernatant is about 6. Centrifuge and filter to obtain the product MXene.

[0046] (2) Prepare a 1 mol / L H2SO4 solution as the doping acid system. Take two 20 ml portions of the prepared 1 mol / L H2SO4 solution, add aniline and ammonium persulfate (APS) to each, stir with a magnetic stirrer for 2 h to mix evenly, let stand for 24 h, and wash the obtained product with ethanol and deionized water by centrifugation several times until neutral. Take the lower precipitate to obtain primary doped polyaniline. With a fixed amount of aniline, add aniline and carbon nanotubes at a mass ratio of 1:5~25 to obtain the primary doped product. Repeat the above operation to prepare graphene / primary doped PANI and MXene / primary doped PANI; (3) Add excess ammonia to the carbon nanotube onion and the primary doped polyaniline compound to dedope, stir with a magnetic stirrer for 1-2 h, let stand at room temperature for 24 h, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain intrinsic polyaniline (carbon nanotube onion / EB-PANI). Graphene / EB-PANI and MXene / EB-PANI can be obtained by repeating the above operations on graphene / PANI and MXene / PANI. (4) The intrinsic product was added to a 1 mol / L H2SO4 solution in different mass ratios, and after sonication and stirring for 2 h, it was allowed to stand for 24 h, washed and centrifuged until neutral, dried and ground to prepare a quaternary composite material of carbon nanotube onion, graphene, MXene and polyaniline.

[0047] The MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer provided in this application can solve the problems of poor compatibility between reactive flame retardants and matrix materials, which easily increase the viscosity of the matrix and make them difficult to apply. This application employs a method of constructing a micro-crosslinked network using nanomaterials to solve this problem. First, reactive MXene with a surface rich in P / N elements is obtained using HF etching, allowing it to participate in aniline polymerization in situ. Simultaneously, it acts as both a flame retardant and a micro-crosslinking agent, forming a tightly bonded interface. Second, a secondary doping method is used to improve the dispersibility of the two-dimensional sheet material, enhance the interfacial compatibility between materials, improve the product morphology, and enhance the flame retardant performance of the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer. Furthermore, the polymerization of polyaniline nanofibers modified with carbon nanoparticles, graphene, and MXene provides a template for polymer skeleton growth, forming a dense network structure. This solves the problems of poor compatibility, easy agglomeration, and difficulty in application of reactive flame retardants in matrix materials.

[0048] refer to Figure 1 As shown, Figure 1(A) is a scanning electron microscope (SEM) image of carbon nanotubes (CNOs). CNOs have a relatively uniform morphology, with a diameter of approximately 80-100 nm, and exhibit agglomeration and adhesion. (B) is a scanning electron microscope (SEM) image of polyaniline (PANI). PANI has a short rod-like morphology, with a length of approximately 300 nm and a diameter of approximately 100 nm, and exhibits severe agglomeration. (C) is a scanning electron microscope (SEM) image of graphene (RGO). (D) is a scanning electron microscope (SEM) image of MXene. MXene has a good two-dimensional layered structure, a large aspect ratio, and good dispersibility. (E) is a scanning electron microscope (SEM) image of CNOs / PANI. During ANI polymerization, PANI can be adsorbed onto the surface of CNOs through intermolecular forces, adsorption, and π-π conjugation. CNOs provide active sites, promoting the growth of polyaniline fibers and forming a spatial network structure. Some CNOs surfaces also have PANI clusters attached, exhibiting a "sea urchin" morphology, constructing a micro-nano-scale rough structure. (F) is a scanning electron microscope (SEM) image of RGO / PANI. PANI can adhere to RGO sheets, and RGO can act as a template during ANI polymerization. (G) is a scanning electron microscope (SEM) image of MXene / PANI. PANI fibers can adhere to MXene sheets, and MXene can provide active sites during ANI polymerization, acting as a template. (H) is a scanning electron microscope (SEM) image of RGO CNOs / RedopedPANI. RGO retains its original layered structure, with a significantly increased interlayer spacing and a marked improvement in packing. PANI can be adsorbed onto the graphene layered structure through intermolecular forces, adsorption, and π-π conjugation. CNOs can act as active sites to extend fiber length, enabling PANI and RGO to form a three-dimensional network layered structure. The length of the composite material reaches over 800 nm. (I) Scanning electron microscope image of MXene CNOs / Redoped PANI. MXene has a large aspect ratio and good dispersibility, and can play a good role as a template in the in-situ polymerization of ANI. MXene retains the original layered structure. PANI can be adsorbed onto the layered structure through intermolecular forces, adsorption, π-π conjugation, etc. PANI clusters grow on its surface, increasing the specific surface area of ​​the composite material and significantly increasing the interlayer spacing between the layered structures. The dispersibility of CNOs and the interlayer spacing of MXene are significantly improved. In the in-situ polymerization of ANI, CNOs can act as active sites to extend fiber length, enabling the composite material to form a three-dimensional network layered structure. (J) Scanning electron microscope image of RGO MXene CNOs / Redoped PANI.As can be clearly seen from the figure, the secondary doping method can effectively prepare quaternary composite materials. The introduction of RGO and MXene better promotes the secondary growth of PANI fibers, improves the aggregation phenomenon between two-dimensional sheet nanomaterials, enhances the interfacial compatibility between different materials, effectively avoids aggregation, and significantly improves the morphology of quaternary composite materials.

[0049] Example 3: This application provides a method for preparing the above-mentioned MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating. The MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating comprises independently packaged component A and component B. Component A and component B are mixed in a 1:1 volume ratio to form the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating. The preparation method of component A includes: 1. Dehydration process for end capping materials (1) Check whether the reactor, auxiliary devices, and vacuum system are operating normally; (2) Weigh 36g of terminal hydroxyl polyether and add it to the reactor for dehydration process; (3) Turn on the stirrer (gradually adjust to medium speed, 600 rpm) and heating device, control the temperature to rise to 105℃ within 30 minutes, turn on the vacuum system, continue to heat up to 110℃, maintain the temperature at 115±3℃, maintain the vacuum degree above 0.075MPa, and vacuum dehydrate for more than 2 hours. (4) Close the vacuum system and open the vent valve, fill with nitrogen to restore atmospheric pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the dehydration process in (3) until the polyether moisture content is lower than 0.5‰. (5) After the moisture content of the polyether is below 0.5‰, turn off the vacuum system and open the vent valve, purge with nitrogen to restore to normal pressure, and cool to a material temperature of <60℃ for later use.

[0050] 2. Preparation of semi-prepolymer (1) Turn on the stirrer and heating device, add 6g of dehydrated hydroxyl-terminated polyether and 60g of isocyanate MDI-50; control the feeding speed and add slowly and evenly within 30 minutes. The feeding should be completed before the material temperature rises to 60℃. (2) After the material is added, the temperature is raised to 75℃ within 20 minutes, and the temperature is controlled at 75±2℃ for 2 hours. Then the temperature is raised to 82℃ within 10 minutes, and the temperature is controlled at 82±2℃ for 2 hours. The material temperature is strictly controlled not to exceed 86℃. (3) After the reaction is complete, stop heating and turn on the cooling device. Control the cooling rate to reduce the material temperature to below 60°C within 20 minutes, and continue stirring for 30 minutes. (4) After filtering with a 100-mesh copper mesh, the product is filled. After filling, the packaging container must be filled with nitrogen for protection to ensure that the packaging container is well sealed, thus obtaining component A. At the same time, a sample is taken to determine the NCO mass fraction of the semi-prepolymer. The test results show that the NCO mass fraction of the semi-prepolymer is 18%, and the isocyanate index is 1.08.

[0051] The preparation methods for component B include: (1) Check whether the reactor and its accessories are operating normally; (2) Metering the materials and adding them to the reactor for dehydration process: First, add 60g of high molecular weight (molecular weight 1000-8000) terminal amino polyether (T-5000) and 15g of MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer and mix. Turn on the stirrer (gradually adjust to medium speed, 600rpm) and heating device. Then add 22g of chain extender E-100. When the temperature reaches 105℃ within 30min, turn on the vacuum system and continue to heat to 110℃. Maintain the temperature at 110±3℃ and the vacuum degree above 0.075MPa. Vacuum dehydration for more than 2h. (3) Close the vacuum system and open the vent valve, fill with nitrogen to restore normal pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat (2) until the moisture content is lower than 0.5‰. (4) After the moisture content is qualified, close the vacuum system and open the vent valve, and fill with nitrogen to restore the pressure to normal.

[0052] (5) 1.8g of pigment titanium dioxide and 1.2g of filler mica iron oxide after metering and grinding were added to the reactor and stirred at high speed (1000rpm) for 1h; (6) Turn on the vacuum system, maintain the vacuum level at 0.075MPa, keep the temperature at 80±2℃, and degas for 15min. (7) Turn off the vacuum system and heating device, stir at low speed, then fill with nitrogen to remove the vacuum, cool to a material temperature of <60℃, filter with a 100-mesh copper mesh and fill. After filling, the packaging barrel must be filled with nitrogen for protection to ensure the packaging container is well sealed and obtain component B.

[0053] In the preparation of component A, the reaction process is strictly controlled by stepwise heating and temperature maintenance to prevent the isocyanate in component A from undergoing accelerated self-polymerization due to excessively high temperatures, thus avoiding excessive NCO consumption and effectively maintaining the NCO content in the system to ensure product performance. Simultaneously, the strict control of stepwise heating and temperature maintenance during the reaction process effectively prevents the reaction from failing to reach the endpoint due to excessively low temperatures, avoiding the presence of large amounts of unreacted hydroxyl groups and NCO in the system, effectively ensuring the flame retardancy and explosion resistance of component A. In the preparation of component B, a process is adopted where high molecular weight amino polyether is first mixed with the flame retardant MXene (Ti3AlC2) multi-component nanocomposite explosion-resistant elastomer, and then low molecular weight polyether polyamine is added. This process effectively avoids the problem of reduced amine value caused by the volatilization loss of low molecular weight polyether polyamine, greatly increasing the stability of the system and the flame retardancy and explosion resistance of the product.

[0054] The MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer used in Example 3 of this application was prepared by the following method: (1) Prepare a 1 mol / L H2SO4 solution as the doping acid system. Take two 20 ml portions of H2SO4 solution and add 0.73 ml of aniline (ANI) and 2.28 g of ammonium persulfate (APS) respectively. Stir the mixture evenly with a magnetic stir bar for 2 h, and let it stand at room temperature for 24 h. Wash the obtained product with ethanol and deionized water by centrifugation several times until neutral. Take the lower precipitate, dry and grind it to obtain primary doped polyaniline. Fix the amount of ANI at 0.73 mL, add different masses of carbon nanotubes (CNOs) to the ANI system, and change the mass ratio m(CNOs):m(ANI) to 1:5, 1:10, 1:15, 1:20, 1:25 to obtain primary doped products with different proportions. Repeat the above operation to prepare graphene (RGO) / primary doped PANI and MXene / primary doped PANI; (2) Using the carbon nanotube onions (CNOs) obtained in (1) and the primary doped polyaniline compound as raw materials, excess ammonia was added for dedoping. The mixture was stirred with a magnetic stirrer for 1-2 h and allowed to stand at room temperature for 24 h. The resulting product was washed with ethanol and deionized water until neutral, and finally dried and ground to obtain intrinsic polyaniline (CNOs / EB-PANI). RGO / EB-PANI and MXene / EB-PANI can be obtained by repeating the above operations on RGO / PANI and MXene / PANI. (3) Using the intrinsic state products of CNOs / EB-PANI15, RGO / EB-PANI25 and MXene / EB-PANI20 obtained in (2) as raw materials, the ratio of the three is changed and added to 1 mol / L H2SO4 in a mass ratio of 3:2:1. After ultrasonic mixing and stirring for 2 h, the mixture is allowed to stand for 24 h. After filtration, it is washed with ethanol and deionized water until neutral. Finally, it is dried and ground to obtain a functional quaternary composite material of carbon nano-onion, graphene and secondary doped polyaniline-MXene compound, that is, MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer material is obtained by drying and grinding.

[0055] Example 4: This application also provides a method for preparing the above-mentioned MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer, the method comprising: (1) Prepare a 1 mol / L H2SO4 solution as the doping acid system. Take two 20 ml portions of the prepared 1 mol / L H2SO4 solution, add aniline and ammonium persulfate (APS) to each, stir with a magnetic stirrer for 2 h to mix evenly, let stand for 24 h, and wash the obtained product with ethanol and deionized water by centrifugation several times until neutral. Take the lower precipitate to obtain primary doped polyaniline. With a fixed amount of aniline, add aniline and carbon nanotubes at a mass ratio of 1:5~25 to obtain the primary doped product. Repeat the above operation to prepare graphene / primary doped PANI and MXene / primary doped PANI; (2) Excess ammonia was added to the carbon nanotube onion and the primary doped polyaniline compound to dedope them. The mixture was stirred with a magnetic stirrer for 1-2 h and allowed to stand at room temperature for 24 h. The resulting product was washed with ethanol and deionized water until neutral, and finally dried and ground to obtain intrinsic polyaniline (carbon nanotube onion / EB-PANI). Graphene / EB-PANI and MXene / EB-PANI can be obtained by repeating the above operations on graphene / PANI and MXene / PANI. (3) The intrinsic product was added to a 1 mol / L H2SO4 solution in different mass ratios, and after sonication and stirring for 2 h, it was allowed to stand for 24 h, washed and centrifuged until neutral, dried and ground to prepare a quaternary composite material of carbon nanotube onion, graphene, MXene and polyaniline.

[0056] The flame-retardant and explosion-proof mechanism of the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer used in this application embodiment is as follows: MXene (Ti3AlC2) multi-component nanocomposite explosion-resistant elastomer material can decompose to produce non-flammable gases such as NH3 and N2 during combustion, thereby diluting the concentration of flammable gases and O2 in the gas phase. It exhibits co-curing characteristics during the elastomer material synthesis process: the functional quaternary composite material of carbon nanoparticles / graphene / polyaniline / MXene compounds acts as a reactive flame retardant, inhibiting the amino polyether reaction in explosion-resistant flame-retardant materials while simultaneously improving the flame-retardant and mechanical properties of the elastomer material.

[0057] In addition, during the polymerization process of MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer material, aniline, graphene, carbon nanotubes, and MXene multi-component materials are tightly and organically combined at the nanoscale through doping and dedoping reactions of H2SO4, ammonium persulfate, and ammonia water. This can form a three-dimensional network structure, construct a more uniform and dense composite structure, and thus develop a quaternary composite material with multiple protection mechanisms and better barrier performance. Among them, (1) polyaniline (PANI) is a conductive polymer with unique redox properties, proton acid doping properties, and good heat resistance. When polyaniline is polymerized in situ, polyaniline is prone to agglomeration and has a short fiber length. In the process of film formation, there are problems such as poor film density. The composite material obtained by the secondary doping method improves the above problems through synergistic effect. (2) Carbon nano-onion has high specific surface area, high thermal conductivity and excellent mechanical properties. It can be used as a flame retardant synergist to enhance the density and stability of the carbon layer. (3) Graphene, as a representative of two-dimensional carbon materials, has extremely high mechanical strength and thermal conductivity. Its sheet structure can complement MXene and further optimize the physical barrier effect. (4) From the perspective of corrosion protection, when the MXene multi-component nanocomposite system coating is applied to the metal surface, it isolates the metal substrate from the external corrosive medium, prolongs the penetration path of the corrosive medium, and shields the external oxygen ions, thereby protecting the metal substrate. In the MXene multi-component nanocomposite system, four components work synergistically to enhance flame retardancy: the layered structure of MXene and graphene forms a physical barrier layer that prevents heat and oxygen transfer; polyaniline captures free radicals during combustion and inhibits chain reactions; carbon nanoparticles promote the formation and stability of a dense carbon layer; and they synergistically improve the flame retardant properties of elastomer materials.

[0058] Therefore, by synergistically incorporating MXene, polyaniline, carbon nanotubes, and graphene into blast-resistant materials, a functional quaternary composite material with co-curing properties is synthesized without compromising the material's mechanical properties, while simultaneously improving the combustion safety and mechanical properties of the elastomer material. Through intrinsic flame-retardant design and co-curing characteristics, the functional quaternary composite material of MXene (Ti3AlC2) multi-component nanocomposite blast-resistant elastomer promotes the formation of a network in the blast-resistant elastomer coating material, which can be uniformly dispersed within the elastomer coating material, forming a labyrinth effect. When the coating material is attacked by flame, self-charging promotes the cross-linking and carbonization of the elastomer coating material, ultimately forming a dense, continuous porous protective carbon layer. The porous, expanding protective carbon layer not only insulates against heat but also creates a labyrinth effect, prolonging the pathway for combustible and toxic gases to escape into contact with the flame, and inhibiting the release of smoke and toxic gases.

[0059] This application provides an MXene (Ti3AlC2) multi-component nanocomposite explosion-proof and flame-retardant coating and its preparation method. MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer is added to component B as a reactive flame retardant. The reactive flame retardant is introduced into the molecular chain of the polymer elastomer material through a chemical reaction between the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer and the terminal amino polyether in component B, achieving intrinsic flame retardancy. The flame-retardant elements are connected in the polymer network by chemical bonds, making it difficult for them to migrate and leach out, resulting in more efficient and durable flame retardancy. Compared with additive flame retardants used in the prior art, the method of using a reactive flame retardant to enhance the flame-retardant effect in this application has a relatively small negative impact on the mechanical properties of the elastomer material matrix, overcoming the problems of significant loss of mechanical properties and easy migration of the introduced flame retardant. By introducing MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer and reacting it with component B, a multifunctional elastomer coating material is obtained. The mechanical properties of the elastomer material are not greatly sacrificed, and may even be improved to a certain extent. It also has the advantages of long-lasting flame retardancy and good thermal stability.

[0060] Reactive flame retardants often suffer from poor compatibility with matrix materials, easily increasing the viscosity of the matrix and hindering their application. This application addresses this problem by constructing a micro-crosslinked network using nanomaterials. First, reactive MXene with a surface rich in P / N elements is obtained using HF etching, allowing it to participate in aniline polymerization in situ. Simultaneously, it acts as both a flame retardant and a micro-crosslinking agent, forming a tightly bonded interface. Second, a secondary doping method is used to improve the dispersibility of the two-dimensional sheet material, enhance interfacial compatibility, and improve the product morphology, thereby increasing the flame retardant performance of the MXene (Ti3AlC2) multi-component nanocomposite explosion-proof elastomer. Furthermore, the polymerization of polyaniline nanofibers modified with carbon nanoparticles, graphene, and MXene provides a template for polymer skeleton growth, forming a dense network structure. This solves the problems of poor compatibility, easy agglomeration, and difficulty in application of reactive flame retardants in matrix materials.

[0061] Flame retardant effect analysis: The sample from the embodiments of this application (coating material with added MXene multi-component nanocomposite explosion-proof elastomer), comparative sample 1 (simple polyurea elastomer coating material), and comparative sample 2 (elastomer coating with added carbon nano-onion / graphene / polyaniline functional material) were simultaneously placed in the same flame combustion environment and deflagration environment for testing. The results were observed and recorded as follows: Comparative sample 1: Combustion occurred at 13 minutes, with a flame tip height greater than 150 mm, internal combustion drippings appeared, and combustion was completed at 8 minutes; Comparative sample 2: Combustion occurred at 16 minutes, with a flame tip height greater than 150 mm, internal combustion drippings appeared, and combustion was completed at 9 minutes; The sample from the embodiments of this application showed no combustion within 60 minutes and did not release large amounts of smoke or toxic gases; This indicates that, compared to comparative sample 1 (simple polyurea elastomer coating material) and comparative sample 2 (elastomer coating with added carbon nanotube onion / graphene / polyaniline functional materials), the MXene multi-component nanocomposite explosion-proof and flame-retardant coating sample of this application has a significant flame-retardant and explosion-proof effect.

[0062] Analysis of Mechanical Property Retention Effect: Based on GB / T 528-2009 "Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber" and GB / T 529-2008 "Determination of Tear Strength of Vulcanized Rubber or Thermoplastic Rubber (Pants-Shaped, Right-Angle, and Crescent-Shaped Specimens)", relevant mechanical property tests were conducted, and the results are as follows: Comparative sample 1: tensile strength 23.62 MPa, tear strength 118.8 N / mm, elongation at break 207.6%; Comparative sample 2: tensile strength 23.75 MPa, tear strength 120.2 N / mm, elongation at break 208.3%; The sample from the embodiments of this application has the following characteristics: tensile strength 25.92 MPa, tear strength 122.7 N / mm, and elongation at break 326.7%. The results show that, compared with comparative sample 1 (simple polyurea elastomer coating material) and comparative sample 2 (elastic coating with added carbon nanotube onion / graphene / polyaniline functional material), the tensile strength, tear strength, and elongation at break of the MXene multi-component nanocomposite explosion-proof and flame-retardant coating sample of this application of the present invention have not decreased and still maintain the mechanical strength of the original material.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A MXene multi-element nanocomposite blast-resistant flame-retardant coating, characterized in that, The MXene multi-element nano composite anti-blast and flame-retardant coating comprises an A component and a B component which are independently packaged, wherein the A component comprises hydroxyl-terminated polyether and isocyanate MDI-50 in a mass ratio of 1:8-20, and the B component comprises amino-terminated polyether, MXene multi-element functional nano composite anti-blast elastomer and chain extender in a mass ratio of 40-80:10-20:15-25.

2. The MXene multi-element nanocomposite blast-resistant fire-retardant paint according to claim 1, characterized in that, The mass ratio of carbon nano onion, graphene and MXene in the MXene multi-element functional nano composite anti-blast elastomer is 2-4:1-3:

1.

3. The MXene multi-element nanocomposite blast-resistant fire-retardant paint according to claim 1, characterized in that, The mass ratio of carbon nano onion, graphene and MXene in the MXene multi-element functional nano composite anti-blast elastomer is 3:2:

1.

4. The MXene multi-element nanocomposite blast-resistant fire-retardant paint of claim 1, wherein, The MXene multi-element functional nano composite anti-blast elastomer contains carbon nano onion, graphene and MXene modified secondary doped polyaniline compounds.

5. The MXene multi-element nanocomposite blast-resistant fire-retardant paint according to claim 3 or 4, characterized in that, The MXene multi-element nanocomposite anti-explosion and flame-retardant coating has an inhibition efficiency greater than 80%, and the MXene multi-element nanocomposite anti-explosion and flame-retardant coating has an impedance value greater than 1800 Ω·cm 2 .

6. The MXene multi-element nanocomposite blast-resistant fire-retardant paint according to claim 3 or 4, characterized in that, The MXene multi-element functional nano composite anti-blast elastomer is prepared by one-time doping, dedoping and secondary doping of carbon nano onion, graphene, MXene and aniline in an H2SO4 solution with ammonium persulfate and ammonia.

7. The MXene multi-element nanocomposite blast-resistant fire-retardant paint according to claim 3 or 4, characterized in that, The MXene multi-element functional nano composite anti-blast elastomer is prepared by the following method: I) Preparation of MXene precursor (11) 30 mL of H2SO4 solution with a concentration of 6 mol / L is measured, and then 98% pure LiF is added to the H2SO4 solution, and a magnetic Teflon stirring rod is used to stir for 4-10 min to ensure that the LiF is completely dissolved; (12) Ti3AlC2 powder is slowly added to the above mixed solution, the temperature of the reaction system is controlled at 30-40 DEG C, and constant temperature reaction is carried out for 20-24 h; (13) After the reaction is completed, distilled water is added to the system, and the product is cleaned by centrifugation-decantation operation for 5 times until the pH value of the supernatant reaches 6, and finally the MXene precursor is obtained by centrifugal filtration; II) Preparation of one-time doped polyaniline-based composite material (21) Two 20 mL H2SO4 solutions with a concentration of 1 mol / L are taken as doped acid solutions, aniline monomer is added to one of them, and ammonium persulfate is added to the other, and after being stirred uniformly with a magnet, the two solutions are mixed and continue to be stirred with a magnet for 2-3 h, and then stand for 24 h for polymerization reaction; (22) After the reaction is completed, the product is washed by alternating centrifugation with ethanol and deionized water for multiple times until the washing liquid is neutral, and the lower layer precipitate is collected to obtain a one-time doped polyaniline preparation system; (23) The amount of aniline monomer is fixed, and carbon nano onion is added to the above one-time doped PANI preparation system in a ratio of 1:5-25 of aniline to carbon nano onion, and the operations of steps (21)-(22) are repeated to prepare carbon nano onion / one-time doped PANI composite material; (24) Replace the carbon nanometer onion with graphene and MXene precursor respectively, keep other experimental conditions unchanged, repeat the above preparation steps (21)~23, and obtain graphene / primary doped state PANI composite material and MXene / primary doped state PANI composite material in turn; III) Preparation of intrinsic state polyaniline-based composite material (31) Add excess ammonia water to the carbon nanometer onion / primary doped state PANI composite material, stir for 1~2 h by using a magnetic stirrer, and then stand still at room temperature for 24 h for de-doping reaction; (32) After the de-doping is completed, wash the product with ethanol and deionized water alternately until the washing liquid is neutral, and then obtain the carbon nanometer onion / intrinsic state polyaniline composite material through drying and grinding treatment; (33) Replace the carbon nanometer onion / primary doped state PANI composite material with graphene / primary doped state PANI composite material and MXene / primary doped state PANI composite material respectively, keep other experimental conditions unchanged, repeat the de-doping, washing, drying and grinding operations of steps (31)~(32), and correspondingly obtain graphene / EB-PANI intrinsic state composite material and MXene / EB-PANI intrinsic state composite material; IV) Final preparation of MXene multi-functional nanocomposite anti-explosive elastomer (41) Mix the carbon nanometer onion / EB-PANI intrinsic state composite material, graphene / EB-PANI intrinsic state composite material and MXene / EB-PANI intrinsic state composite material with a preset mass ratio uniformly, and then add them to a H2SO4 solution with a concentration of 1 mol / L; (42) Ultrasonically treat the above mixed system, and then stir for 2~3 h by using a magnetic stirrer to ensure that the components are fully dispersed and a secondary doping reaction occurs, and then stand still for 24 h; (43) After the secondary doping reaction is completed, wash the product to neutral, and then obtain the carbon nanometer onion-graphene-MXene-secondary doped state polyaniline quaternary functional composite MXene multi-functional nanocomposite anti-explosive elastomer through centrifugal separation, drying and grinding.

8. The MXene multi-element nanocomposite blast-resistant fire-retardant paint according to claim 3 or 4, characterized in that, The A component is prepared by using the following method: (1) According to the mass ratio of hydroxyl-terminated polyether and isocyanate MDI-50 being 1:8~20, the hydroxyl-terminated polyether is added to a reaction kettle for dehydration process operation, wherein the temperature is controlled to be increased to 105℃ within 30 min, then the vacuum system is opened, the temperature is continuously increased to 110℃, the temperature is kept at 115±3℃, the vacuum degree is kept above 0.075 MPa, and the dehydration is performed for more than 2 h under vacuum; (2) Close the vacuum system and open the exhaust valve, restore to normal pressure by filling nitrogen, take a sample to measure the moisture content, if the moisture content is still higher than 0.5‰, repeat the dehydration process operation until the moisture content of the polyether is lower than 0.5‰, when the moisture content of the polyether is lower than 0.5‰, close the vacuum system and open the exhaust valve, restore to normal pressure by filling nitrogen, and cool to a material temperature of <60℃ to obtain the dehydrated hydroxyl-terminated polyether; (3) Start the stirrer and heating device, and add the isocyanate MDI-50 into the hydroxyl-terminated polyether according to the mass ratio of 1:8-20, control the feeding speed, and slowly and uniformly add the isocyanate MDI-50 within 30 min, and the feeding is required to be completed before the material temperature rises to 60 DEG C; (4) After the feeding is completed, control the temperature to rise to 75 DEG C within 20 min, control the temperature at 75 DEG C + / - 2 DEG C for 2 h, then control the temperature to rise to 82 DEG C within 10 min, control the temperature at 82 DEG C + / - 2 DEG C for 2 h, and strictly control the material temperature to be less than 86 DEG C during the reaction; (5) After the reaction is completed, stop heating, and start the cooling device, control the cooling speed to make the material temperature to be less than 60 DEG C within 20 min, continue stirring for 30 min, then filter through a 100 mesh copper screen, and fill the package, and the package barrel is required to be filled with nitrogen gas for protection after filling, ensure the sealing performance of the package container, and obtain the A component in independent sealed package.

9. The MXene multi-element nanocomposite blast-resistant fire-retardant coating of claim 3 or 4, wherein, The B component is prepared by the following method: (1) according to the mass ratio of 40-80:10-20:15-25 of the amino-terminated polyether, the MXene multi-element nanocomposite anti-explosive elastomer and the chain extender, first add the amino-terminated polyether and the MXene multi-element nanocomposite anti-explosive elastomer for mixing, then add the chain extender after starting the stirrer and heating device, control the temperature to rise to 105 DEG C within 30 min, start the vacuum system, continue to heat to 110 DEG C, keep the temperature at 110 DEG C + / - 3 DEG C, keep the vacuum degree above 0.075 MPa, and dehydrate for more than 2 h; (2) close the vacuum system and open the exhaust valve, restore to normal pressure by filling nitrogen gas, take a sample to measure the moisture content, if the moisture content is still higher than 0.5 ‰, repeat the vacuum dehydration operation until the moisture content is less than 0.5 ‰; (3) after the moisture content is less than 0.5 ‰, close the vacuum system and open the exhaust valve, restore to normal pressure by filling nitrogen gas, then add the ground pigment titanium dioxide and the filler mica iron oxide into the reaction kettle, and stir at high speed for 1 h; (4) start the vacuum system, keep the vacuum degree at 0.075 MPa, keep the temperature at 80 DEG C + / - 2 DEG C, deaerate for 15 min, stop the vacuum system and the heating device, stir at low speed, then fill nitrogen gas to remove the vacuum, cool to a material temperature < 60 DEG C, filter through a 100 mesh copper screen, and fill the package, and the package barrel is required to be filled with nitrogen gas for protection after filling, ensure the sealing performance of the package container, and obtain the B component in independent sealed package.

10. A MXene multi-element nanocomposite blast-resistant and flame-retardant coating layer prepared by using the MXene multi-element nanocomposite blast-resistant and flame-retardant coating material according to any one of claims 1-9, characterized in that, Mix the A component and the B component packaged independently according to the volume ratio of 1:1, then coat on the surface of the substrate by spraying, brushing or scraping, and form a MXene multi-element nanocomposite anti-explosive and flame-retardant coating layer with a thickness of 200-400 mu m after room temperature curing, and the substrate is metal, plastic or ceramic material.

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