A type of Mxene nanohybrid material and its application in flame-retardant foam materials

Abstract

This invention relates to the field of nanomaterials, specifically to an Mxene nanohybrid material and its application in flame-retardant foam materials. The preparation of the Mxene nanohybrid material includes the following steps: Step 1, obtaining amination-modified MXene nanosheets; Step 2, obtaining thiolized halloysite nanotubes; Step 3, obtaining modified MXene nanosheets; Step 4, obtaining the MXene nanohybrid material. The MXene nanohybrid material prepared by this invention not only has good compatibility with polyurethane foam, but also provides a large number of nucleation sites for the polyurethane foam system, acting as a foam stabilizer. This results in the final polyurethane foam material possessing multiple advantages such as high strength, high flame retardancy, and high thermal conductivity.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials, specifically to an Mxene nanohybrid material and its application in flame-retardant foam materials. Background Technology

[0002] Polyurethane foam is one of the most important types of polyurethane materials. Its porous structure gives it advantages such as low density, high strength, and high thermal insulation, making it widely used in shock absorption, vibration damping, soft padding materials, and building insulation. However, polyurethane foam contains a large number of hydrocarbon segments, making it highly flammable, with a limiting oxygen index (LOI) of only 17%-19%. Upon ignition, it burns rapidly, releasing a large amount of heat, accompanied by smoke and toxic gases (CO, HCN, NO, etc.), posing a serious threat to people's lives and property. With the high-tech industry imposing stricter fire safety standards on polyurethane foam materials, research on the preparation of high-flame-retardant polyurethane foam is urgent and necessary. However, traditional flame-retardant coating strategies for polyurethane foam, such as in-situ deposition, plasma technology, sol-gel processes, and layer-by-layer self-assembly techniques, still suffer from poor coating durability and complex processes. Additive flame retardants have poor compatibility with the substrate, are easily leachable, and readily deteriorate the foam's mechanical properties, especially under extreme natural conditions such as humid heat corrosion, alternating high and low temperatures day and night, and high-frequency compression recovery, making long-term flame retardancy impossible. Therefore, developing flame-retardant polyurethane foam technology with long-lasting flame retardancy and reinforcement is more favored for future industrial applications and has a bright future.

[0003] MXenes are a class of two-dimensional transition metal carbides / nitrides / carbonitrides, widely used in polymer composites due to their excellent impermeability, rich surface chemistry, superior mechanical properties, and metal-like electrical and thermal conductivity. In recent years, MXenes, two-dimensional transition metal carbonitrides, have shown great promise for the design of highly efficient flame-retardant systems due to their good smoke suppression properties and tunable surface functional groups. However, current development of MXene-based synergistic flame retardants still falls short of meeting the high flame-retardant requirements of polymer materials. Furthermore, the synergistic flame-retardant effect between MXenes and traditional flame retardants remains unclear, and achieving high flame-retardant levels with only a small amount of MXene in a synergistic flame retardant formulation remains a challenge. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this invention is to provide an MXene nano-hybrid material and a reinforced flame-retardant polyurethane foam material, so as to overcome the shortcomings of the prior art and improve the flame-retardant, mechanical and other properties of polyurethane foam materials.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing MXene nano-hybrid materials, comprising the following steps:

[0007] Step 1, MXene nanosheets (Ti3C2T) x Add the mixture to deionized water, disperse it thoroughly under ultrasonic conditions, add polyamine, heat to 40-60℃, treat for 2-6 hours, filter, wash and dry to obtain amination-modified MXene nanosheets;

[0008] Step 2: Add halloysite nanotubes to an ethanol aqueous solution, disperse them thoroughly under ultrasonic conditions, then add 3-mercaptopropyltriethoxysilane, heat to 55-75℃, reflux for 3-8 hours, filter, wash and dry to obtain mercapto-modified halloysite nanotubes.

[0009] Step 3: Weigh glycidyl methacrylate and dissolve it in anhydrous ethanol, then add amination-modified MXene nanosheets, heat to 70-80℃, reflux and stir for 2-6 hours, remove the solvent by rotary evaporation to obtain modified MXene nanosheets.

[0010] Step 4: Thiolized halloysite nanotubes and modified MXene nanosheets are added to toluene and ultrasonically dispersed. Under the protection of nitrogen, a photosensitizer is added and the mixture is stirred under ultraviolet irradiation for 0.5-2.5 hours. After treatment, the mixture is filtered, washed and dried to obtain MXene nanohybrid material.

[0011] Preferably, in step 1, the particle size of the MXene nanosheets is 3-6 μm.

[0012] Preferably, in step 1, the method for preparing MXene nanosheets includes:

[0013] LiF was added to hydrochloric acid solution and stirred thoroughly in an ice-water bath to dissolve it. Then, the precursor Ti3AlC2 was slowly added to the solution. After all the precursor was added, the mixture was kept warm and stirred for 1-2 hours. Then, the temperature was raised to 30-40℃ and stirred for 20-50 hours. After the treatment was completed, the mixture was filtered, washed and dried to obtain MXene nanosheets.

[0014] More preferably, the mass fraction of the hydrochloric acid solution is 28%-33%, and the mass-volume ratio of the precursor Ti3AlC2, LiF and the hydrochloric acid solution is (4-6)g:(6-12)g:(100-200)mL.

[0015] Preferably, in step 1, the polyamine is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0016] Preferably, in step 1, the mass-to-volume ratio of MXene nanosheets, polyamines, and deionized water is (0.1-0.3)g:(0.01-0.04)g:(10-30)mL.

[0017] Preferably, in step 2, the particle size of halloysite nanotubes is 100-300 nm.

[0018] Preferably, in step 2, the mass fraction of the ethanol aqueous solution is 20%-80%.

[0019] Preferably, in step 2, the mass-to-volume ratio of halloysite nanotubes, 3-mercaptopropyltriethoxysilane, and aqueous ethanol solution is 1 g:(0.1-0.3) g:(10-30) mL.

[0020] Preferably, in step 3, the mass-volume ratio of amination MXene nanosheets, glycidyl methacrylate, and anhydrous ethanol is 1g:(0.3-0.7)g:(10-30)mL.

[0021] Preferably, in step 4, the mass-volume ratio of modified MXene nanosheets, mercaptolated halloysite nanotubes, and toluene is 1g:(0.5-1)g:(20-30)mL.

[0022] Preferably, in step 4, the photosensitizer is one or more of benzoin methyl ether, benzoin ethyl ether, benzoin dimethyl ether, and benzoin diethyl ether.

[0023] Preferably, in step 4, the amount of photosensitizer added is 1%-5% of the mass of mercaptoil halloysite nanotubes.

[0024] Preferably, in step 4, the wavelength of the ultraviolet light is 365 nm, and the light intensity is 50-250 mW / cm². 2 .

[0025] Secondly, the present invention provides an application of MXene nano-hybrid material in polyurethane foam material, wherein the polyurethane foam material comprises the following components in parts by weight: 100 parts polyether polyol, 50-250 parts polyisocyanate, 5-15 parts MXene nano-hybrid material, 2-6 parts catalyst and 3-10 parts water.

[0026] Preferably, the polyether polyol is one or more of castor oil polyether polyol (hydroxyl value, 190-220 mg KOH / g), glycerol polyether polyol (hydroxyl value, 185-200 mg KOH / g), sorbitol polyether polyol (hydroxyl value, 300-320 mg KOH / g), and sucrose polyether polyol (hydroxyl value, 750-770 mg KOH / g).

[0027] Preferably, the polyisocyanate is a polymethylene polyphenyl polyisocyanate, and the isocyanate content is 30%.

[0028] Preferably, the catalyst is catalyst T12.

[0029] Preferably, the method for preparing the polyurethane foam material includes:

[0030] (1) Mix and stir the polyether polyol, MXene nano-hybrid material, catalyst and water at a speed of 300-500 r / min for 5-10 min to obtain a mixture;

[0031] (2) Add polyisocyanate to the mixture in step (1), stir at 300-500 r / min, mix for 10-15 seconds and immediately pour into a mold for foaming to obtain flame-retardant foam material.

[0032] The beneficial effects of this invention are as follows:

[0033] 1. This invention prepares an MXene nano-hybrid material and uses it to obtain a reinforced flame-retardant polyurethane foam material. The MXene nano-hybrid material prepared by this invention not only has good compatibility with polyurethane foam, but also provides a large number of nucleation sites for the polyurethane foam system, acting as a foam stabilizer. This results in the final polyurethane foam material having multiple advantages such as high strength, high flame retardancy, and high thermal conductivity.

[0034] 2. This invention utilizes the functional groups such as -NH2 on polyamines and -OH and -F on the MXene interface to self-assemble and form a stable MXene-based sandwich structure with a self-healing hydrogen bond network. On one hand, the hydrogen bond network can regulate the interlayer spacing of MXene; on the other hand, the abundant amino groups provide additional cross-linking active sites. Then, the aminated MXene nanosheets undergo an amino-epoxy group binding reaction with glycidyl methacrylate to obtain modified MXene nanosheets. Halloysite nanotubes are activated using a mercaptosilane coupling agent to impart mercaptohydration, and then undergo a mercapto-double bond click chemistry reaction with the modified MXene nanosheets containing unsaturated bonds, ultimately yielding an MXene nanohybrid material.

[0035] 3. This invention modifies polyurethane foam material with MXene nano-hybrid material to obtain reinforced flame-retardant polyurethane foam material. The polyurethane foam material of this invention has the characteristics of high strength, flame retardancy and excellent thermal conductivity. The prepared polyurethane foam material can be used in the fields of shock absorbers for fuel vehicles and electric vehicles, sealing, shock absorption and dust prevention of 3C product devices, protection of new energy battery cells, insulation of boxes and protection of modules.

[0036] 4. The preparation process of the MXene nano-hybrid material and polyurethane foam material described in this invention is simple, environmentally friendly, and suitable for industrial production. Attached Figure Description

[0037] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the SEM image obtained in Example 1 of the present invention. Detailed Implementation

[0039] The technical solution of the present invention is illustrated below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or defining the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0040] To better understand the above technical solutions, exemplary embodiments of the present invention are described in more detail below. While exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0041] The present invention will be further described below with reference to the following embodiments.

[0042] Example 1

[0043] A method for preparing MXene nanohybrid materials includes the following steps:

[0044] Step 1: LiF was added to a 31% hydrochloric acid solution and stirred thoroughly in an ice-water bath to dissolve it. Then, the precursor Ti3AlC2 was slowly added to the solution. The mass-volume ratio of the precursor Ti3AlC2, LiF, and hydrochloric acid solution was 5g:9g:150mL. After all the precursor was added, the mixture was kept warm and stirred for 1.5h. Then, the temperature was raised to 35℃ and kept warm and stirred for 30h. After the treatment was completed, the mixture was filtered, washed, and dried to obtain MXene nanosheets with a particle size of 3-6μm.

[0045] Step 2, MXene nanosheets (Ti3C2T) x Add the MXene nanosheets to deionized water and disperse them thoroughly under ultrasonic conditions. Then add triethylenetetramine. The mass-volume ratio of MXene nanosheets, triethylenetetramine, and deionized water is 0.2 g: 0.03 g: 20 mL. Heat to 50 °C and treat for 4 h. After filtration, washing, and drying, amination-modified MXene nanosheets are obtained.

[0046] Step 3: Halloysite nanotubes with a particle size of 100-300 nm were added to a 50% ethanol aqueous solution and dispersed thoroughly under ultrasonic conditions. Then, 3-mercaptopropyltriethoxysilane was added. The mass-volume ratio of halloysite nanotubes, 3-mercaptopropyltriethoxysilane and ethanol aqueous solution was 1 g:0.2 g:20 mL. The mixture was heated to 65 °C and refluxed for 5 h. After filtration, washing and drying, mercapto-modified halloysite nanotubes were obtained.

[0047] Step 4: Weigh glycidyl methacrylate and dissolve it in anhydrous ethanol. Then add amination MXene nanosheets. The mass-volume ratio of amination MXene nanosheets, glycidyl methacrylate and anhydrous ethanol is 1g:0.5g:20mL. Heat to 75℃, reflux and stir for 4h. Remove the solvent by rotary evaporation to obtain modified MXene nanosheets.

[0048] Step 5: Add mercaptolated halloysite nanotubes and modified MXene nanosheets to toluene. The mass-to-volume ratio of modified MXene nanosheets, mercaptolated halloysite nanotubes, and toluene is 1 g:0.6 g:25 mL. Disperse the mixture evenly by ultrasonication. Under nitrogen protection, add benzoin dimethyl ether at 3% of the mass of mercaptolated halloysite nanotubes. The wavelength is 365 nm and the light intensity is 150 mW / cm². 2 The material was stirred under ultraviolet light irradiation for 1.5 h. After the treatment, it was filtered, washed and dried to obtain MXene nano-hybrid material.

[0049] The above-mentioned MXene nano-hybrid material is applied in a polyurethane foam material, which comprises the following components in parts by weight: 100 parts castor oil polyether polyol, 57.3 parts polymethylene polyphenyl polyisocyanate, 10 parts MXene nano-hybrid material, 4 parts catalyst T12, and 4 parts water.

[0050] The preparation methods for polyurethane foam materials include:

[0051] (1) Castor oil polyether polyol (hydroxyl value, 190-220 mg KOH / g), MXene nano-hybrid material, catalyst and water are mixed and stirred at 400 r / min for 8 min to obtain a mixture;

[0052] (2) Add polymethylene polyphenyl polyisocyanate (isocyanate content is 30%) to the mixture in step (1), stir at 400 r / min, mix for 12 seconds and immediately pour into the mold for foaming to obtain flame retardant foam material.

[0053] Example 2

[0054] A method for preparing MXene nanohybrid materials includes the following steps:

[0055] Step 1: LiF was added to a 28% hydrochloric acid solution and stirred thoroughly in an ice-water bath to dissolve it. Then, the precursor Ti3AlC2 was slowly added to the solution. The mass-volume ratio of the precursor Ti3AlC2, LiF and hydrochloric acid solution was 4g:6g:100mL. After all the solution was added, the mixture was kept warm and stirred for 1 hour. Then, the temperature was raised to 30℃ and kept warm and stirred for 20 hours. After the treatment was completed, the mixture was filtered, washed and dried to obtain MXene nanosheets with a particle size of 3-6μm.

[0056] Step 2, MXene nanosheets (Ti3C2T) x Add the MXene nanosheets to deionized water and disperse them thoroughly under ultrasonic conditions. Then add ethylenediamine. The mass-volume ratio of MXene nanosheets, ethylenediamine, and deionized water is 0.1 g: 0.01 g: 10 mL. Heat to 40 °C and treat for 2 h. After filtration, washing, and drying, amination-modified MXene nanosheets are obtained.

[0057] Step 3: Halloysite nanotubes with a particle size of 100-300 nm were added to a 20% (w / w) ethanol aqueous solution and dispersed thoroughly under ultrasonic conditions. Then, 3-mercaptopropyltriethoxysilane was added. The mass-volume ratio of halloysite nanotubes, 3-mercaptopropyltriethoxysilane and ethanol aqueous solution was 1 g:0.1 g:10 mL. The mixture was heated to 55 °C and refluxed for 3 h. After filtration, washing and drying, mercapto-modified halloysite nanotubes were obtained.

[0058] Step 4: Weigh glycidyl methacrylate and dissolve it in anhydrous ethanol. Then add amination MXene nanosheets. The mass-volume ratio of amination MXene nanosheets, glycidyl methacrylate and anhydrous ethanol is 1g:0.3g:10mL. Heat to 70℃, reflux and stir for 2h, and remove the solvent by rotary evaporation to obtain modified MXene nanosheets.

[0059] Step 5: Add mercaptolated halloysite nanotubes and modified MXene nanosheets to toluene. The mass-to-volume ratio of modified MXene nanosheets, mercaptolated halloysite nanotubes, and toluene is 1 g:0.5 g:20 mL. Disperse the mixture evenly by ultrasonication. Under nitrogen protection, add benzoin methyl ether at 1% of the mass of mercaptolated halloysite nanotubes. The wavelength is 365 nm and the light intensity is 50 mW / cm². 2 The material was stirred under ultraviolet light irradiation for 2.5 h. After the treatment, it was filtered, washed and dried to obtain MXene nano-hybrid material.

[0060] The above-mentioned MXene nano-hybrid material is applied in a polyurethane foam material, which comprises the following components in parts by weight: 100 parts of glycerol polyether polyol, 53.8 parts of polymethylene polyphenyl polyisocyanate, 5 parts of MXene nano-hybrid material, 2 parts of catalyst T12, and 3 parts of water.

[0061] The preparation methods for polyurethane foam materials include:

[0062] (1) Glyceryl polyether polyol (hydroxyl value, 185-200 mg KOH / g), MXene nano-hybrid material, catalyst and water are mixed and stirred at 300 r / min for 5 min to obtain a mixture;

[0063] (2) Add polymethylene polyphenyl polyisocyanate (isocyanate content is 30%) to the mixture in step (1), stir at 300 r / min, mix for 10 seconds and immediately pour into the mold for foaming to obtain flame retardant foam material.

[0064] Example 3

[0065] A method for preparing MXene nanohybrid materials includes the following steps:

[0066] Step 1: LiF was added to a 33% hydrochloric acid solution and stirred thoroughly in an ice-water bath to dissolve it. Then, the precursor Ti3AlC2 was slowly added to the solution. The mass-volume ratio of the precursor Ti3AlC2, LiF and hydrochloric acid solution was 6g:12g:200mL. After all the solution was added, the mixture was kept warm and stirred for 2 hours. Then, the temperature was raised to 40℃ and kept warm and stirred for 50 hours. After the treatment was completed, the mixture was filtered, washed and dried to obtain MXene nanosheets with a particle size of 3-6μm.

[0067] Step 2, MXene nanosheets (Ti3C2T) xAdd the MXene nanosheets to deionized water and disperse them thoroughly under ultrasonic conditions. Then add diethylenetriamine. The mass-volume ratio of MXene nanosheets, diethylenetriamine, and deionized water is 0.3 g: 0.04 g: 30 mL. Heat to 60 °C and treat for 6 h. After filtration, washing, and drying, amination-modified MXene nanosheets are obtained.

[0068] Step 3: Halloysite nanotubes with a particle size of 100-300 nm were added to an 80% ethanol aqueous solution and dispersed thoroughly under ultrasonic conditions. Then, 3-mercaptopropyltriethoxysilane was added. The mass-volume ratio of halloysite nanotubes, 3-mercaptopropyltriethoxysilane and ethanol aqueous solution was 1 g:0.3 g:30 mL. The mixture was heated to 75 °C and refluxed for 8 h. After filtration, washing and drying, mercapto-modified halloysite nanotubes were obtained.

[0069] Step 4: Weigh glycidyl methacrylate and dissolve it in anhydrous ethanol. Then add amination MXene nanosheets. The mass-volume ratio of amination MXene nanosheets, glycidyl methacrylate and anhydrous ethanol is 1g:0.7g:30mL. Heat to 80℃, reflux and stir for 6h. Remove the solvent by rotary evaporation to obtain modified MXene nanosheets.

[0070] Step 5: Add mercaptolated halloysite nanotubes and modified MXene nanosheets to toluene at a mass-to-volume ratio of 1 g:1 g:30 mL. Disperse the mixture evenly using ultrasonication. Under nitrogen protection, add benzoin diethyl ether at 5% of the mass of the mercaptolated halloysite nanotubes. The wavelength is 365 nm and the light intensity is 250 mW / cm². 2 The material was stirred under ultraviolet light irradiation for 0.5 h. After the treatment, it was filtered, washed and dried to obtain MXene nano-hybrid material.

[0071] The above-mentioned MXene nano-hybrid material is applied in a polyurethane foam material, which comprises the following components in parts by weight: 100 parts of sorbitol polyether polyol, 212.5 g parts of polymethylene polyphenyl polyisocyanate, 15 parts of MXene nano-hybrid material, 6 parts of catalyst T12, and 10 parts of water.

[0072] The preparation methods for polyurethane foam materials include:

[0073] (1) Sorbitol polyether polyol (hydroxyl value, 300-320 mg KOH / g), MXene nano-hybrid material, catalyst and water were mixed and stirred at 500 r / min for 10 min to obtain a mixture;

[0074] (2) Add polymethylene polyphenyl polyisocyanate (isocyanate content is 30%) to the mixture in step (1), stir at 500 r / min, mix for 15 seconds and immediately pour into the mold for foaming to obtain flame retardant foam material.

[0075] Comparative Example 1

[0076] An MXene nanohybrid material, differing from Example 1 in that it directly combines amination-modified MXene nanosheets and halloysite nanotubes, and the preparation method includes:

[0077] Step 1: Prepare amination-modified MXene nanosheets, the same as in Example 1;

[0078] Step 2: Halloysite nanotubes and aminated MXene nanosheets are added to toluene. The mass-volume ratio of aminated MXene nanosheets, halloysite nanotubes and toluene is 1g:0.6g:25mL. The mixture is heated to 75℃, refluxed and stirred for 4h, and the solvent is removed by rotary evaporation to obtain MXene nanohybrid material.

[0079] The obtained MXene nano-hybrid material was applied to polyurethane foam material, and the composition and preparation method of the polyurethane foam material were the same as those in Example 1.

[0080] Comparative Example 2

[0081] An MXene nanohybrid material, differing from Example 1 in that it directly combines MXene nanosheets and thiolized halloysite nanotubes, and the preparation method includes:

[0082] Step 1: Prepare MXene nanosheets, the same as in Example 1;

[0083] Step 2, prepare mercaptolated halloysite nanotubes, the same as in Example 1;

[0084] Step 3: Add mercaptolated halloysite nanotubes and MXene nanosheets to toluene. The mass-volume ratio of MXene nanosheets, mercaptolated halloysite nanotubes and toluene is 1 g: 0.6 g: 25 mL. Heat to 75 °C, reflux and stir for 4 h, and remove the solvent by rotary evaporation to obtain MXene nanohybrid material.

[0085] The obtained MXene nano-hybrid material was applied to polyurethane foam material, and the composition and preparation method of the polyurethane foam material were the same as those in Example 1.

[0086] Comparative Example 3

[0087] An MXene nanohybrid material, differing from Example 1 in that it directly combines amination-modified MXene nanosheets, glycidyl methacrylate, and halloysite nanotubes. The preparation method includes:

[0088] Step 1: Prepare amination-modified MXene nanosheets, the same as in Example 1;

[0089] Step 2: Weigh glycidyl methacrylate and dissolve it in anhydrous ethanol. Then add amination MXene nanosheets and halloysite nanotubes. The mass-volume ratio of amination MXene nanosheets, halloysite nanotubes, glycidyl methacrylate and anhydrous ethanol is 1g:0.6g:0.5g:20mL. Heat to 75℃, reflux and stir for 4h. Remove the solvent by rotary evaporation to obtain MXene nano-hybrid material.

[0090] The obtained MXene nano-hybrid material was applied to polyurethane foam material, and the composition and preparation method of the polyurethane foam material were the same as those in Example 1.

[0091] Experimental testing:

[0092] The properties of the polyurethane foam materials prepared in Example 1 and Comparative Examples 1-3 were tested. The test items included compressive strength (refer to standard GB / T 8813-2020), horizontal burning rate (refer to standard ASTM D4986), vertical burning time (refer to standard UL 94), flame retardancy rating (refer to standard UL 94), and thermal conductivity (refer to standard GB / T10294-2008). The test results are shown in Table 1.

[0093] Table 1 Performance test results of different polyurethane foam materials

[0094] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Compressive strength (kPa) 278.0 193.7 211.2 234.5 Vertical combustion time (s) 40.1 20.8 25.1 21.9 Horizontal combustion rate (mm / min) 54.2 100.4 81.5 97.8 Flame retardant rating (UL94) V-0 V-1 V-1 V-1 <![CDATA[Thermal conductivity (W•(m•K) -1 )]]> 0.037 0.041 0.039 0.034

[0095] As can be seen from the test results in Table 1, the polyurethane foam material prepared in Example 1 of the present invention has significantly better strength and flame retardancy than comparative examples 1-3, and can also maintain good thermal conductivity, indicating that the polyurethane foam material prepared in Example 1 of the present invention has multiple advantages such as high strength, high flame retardancy, and high thermal conductivity.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," 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. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring 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. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0097] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing MXene nanohybrid materials, characterized in that, Includes the following steps: Step 1: Add MXene nanosheets to deionized water, disperse them thoroughly under ultrasonic conditions, add polyamine, heat to 40-60℃, treat for 2-6 hours, filter, wash and dry to obtain amination-modified MXene nanosheets; Step 2: Add halloysite nanotubes to an ethanol aqueous solution, disperse them thoroughly under ultrasonic conditions, then add 3-mercaptopropyltriethoxysilane, heat to 55-75℃, reflux for 3-8 hours, filter, wash and dry to obtain mercapto-modified halloysite nanotubes. Step 3: Weigh glycidyl methacrylate and dissolve it in anhydrous ethanol, then add amination-modified MXene nanosheets, heat to 70-80℃, reflux and stir for 2-6 hours, remove the solvent by rotary evaporation to obtain modified MXene nanosheets. Step 4: Thiolized halloysite nanotubes and modified MXene nanosheets are added to toluene and ultrasonically dispersed. Under the protection of nitrogen, a photosensitizer is added and the mixture is stirred under ultraviolet irradiation for 0.5-2.5 hours. After treatment, the mixture is filtered, washed and dried to obtain MXene nanohybrid material.

2. The method for preparing an MXene nanohybrid material according to claim 1, characterized in that, In step 1, the method for preparing MXene nanosheets includes: LiF was added to hydrochloric acid solution and dissolved thoroughly under ice-water bath conditions. Then, the precursor Ti3AlC2 was slowly added to the solution. After all the precursor was added, the mixture was kept warm and stirred for 1-2 hours. Then, the temperature was raised to 30-40℃ and stirred for 20-50 hours. After the treatment was completed, the mixture was filtered, washed and dried to obtain MXene nanosheets. The mass fraction of the hydrochloric acid solution was 28%-33%, and the mass-volume ratio of the precursor Ti3AlC2, LiF and hydrochloric acid solution was (4-6) g:(6-12) g:(100-200) mL.

3. The method for preparing an MXene nanohybrid material according to claim 1, characterized in that, In step 1, the polyamine is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

4. The method for preparing an MXene nanohybrid material according to claim 1, characterized in that, In step 1, the mass-to-volume ratio of MXene nanosheets, polyamines, and deionized water is (0.1-0.3)g:(0.01-0.04)g:(10-30)mL.

5. The method for preparing an MXene nanohybrid material according to claim 1, characterized in that, In step 2, the mass-to-volume ratio of halloysite nanotubes, 3-mercaptopropyltriethoxysilane, and aqueous ethanol solution is 1 g:(0.1-0.3) g:(10-30) mL.

6. The method for preparing an MXene nanohybrid material according to claim 1, characterized in that, In step 3, the mass-volume ratio of amination MXene nanosheets, glycidyl methacrylate, and anhydrous ethanol is 1 g:(0.3-0.7) g:(10-30) mL.

7. The method for preparing an MXene nanohybrid material according to claim 1, characterized in that, In step 4, the mass-volume ratio of modified MXene nanosheets, mercaptolated halloysite nanotubes, and toluene is 1 g:(0.5-1) g:(20-30) mL.

8. An MXene nanohybrid material, characterized in that, The MXene nanohybrid material was prepared using the preparation method described in claim 1.

9. The application of the MXene nanohybrid material according to claim 8 in polyurethane foam materials.

10. The application of the MXene nanohybrid material according to claim 9 in polyurethane foam materials, characterized in that, The polyurethane foam material comprises the following components in parts by weight: 100 parts polyether polyol, 50-250 parts polyisocyanate, 5-15 parts MXene nano-hybrid material, 2-6 parts catalyst and 3-10 parts water.

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