Preparation method of high-self-recovery biomass flame-retardant hydrogel

Abstract

The invention discloses a preparation method of high-self-recovery biomass flame-retardant hydrogel, and relates to the technical field of biomass material preparation, the field of high polymer materials, the field of hydrogel and the field of flame-retardant materials. The invention aims to solve the technical problems that the existing flame-retardant hydrogel is poor in mechanical property, complex in method, too high in cost and not environment-friendly. The method comprises the following steps: preparing a dispersion liquid from montmorillonite and cellulose; adding the silane hydrolysis solution into a phytic acid aqueous solution to prepare a phytic acid silane hydrolysis solution; and mixing cellulose, the phytic acid silane hydrolysis solution and the precursor solution, and adding an initiator to prepare the high-self-recovery biomass flame-retardant hydrogel. The prepared product is environment-friendly and harmless; the performance of the hydrogel is improved; and the preparation process is simplified. The hydrogel prepared by the method is applied to the field of flame retardance of high polymer materials.

Description

Technical Field

[0001] The present invention relates to the technical fields of biomass material preparation, polymer materials, hydrogels, and flame retardant materials. Background Art

[0002] Hydrogel is a kind of hydrophilic polymer material with a three-dimensional network structure. The internal dense and regular porous structure can absorb thousands of times its own mass of water, and at the same time can tightly lock the water. It is a good fire extinguishing base material, which overcomes the defect of water loss during the fire extinguishing process when using flowing water alone, and effectively improves the utilization rate of water. Also, due to its good biocompatibility, water absorption, and water retention, it is widely used in the fields of biomedicine, drug delivery, tissue engineering, etc. However, traditional hydrogels have some limitations in mechanical properties, such as low strength and being fragile, which greatly limits their application scope. At the same time, with the improvement of environmental awareness, the demand for flame retardant materials is also increasing continuously. Especially in the fields of construction, transportation, and electronics, the requirements for flame retardant performance are getting higher and higher. Therefore, the research on flame retardant by modifying hydrogels is one of the current hotspots.

[0003] In recent years, in order to modify the mechanical properties of hydrogels and improve their application in the field of flame retardancy, the existing solutions mainly enhance the mechanical properties of hydrogels through chemical crosslinking. For example, by adding crosslinking agents such as glutaraldehyde, N,N'-methylenebisacrylamide, etc., to form a chemical crosslinking network in the hydrogel. However, due to the irreversibility of chemical crosslinking, it will affect the toughness and self-recovery performance of the hydrogel, which may affect the use effect of the hydrogel, thus limiting its application in the fields of structural materials, load-bearing materials, etc. And by adding flame retardants to improve the flame retardant performance of hydrogels. For example, by adding halogenated flame retardants, such as brominated flame retardants, to the hydrogel to improve its flame retardant performance. However, although these flame retardants can improve the flame retardant performance of hydrogels to a certain extent, their use often causes environmental pollution, and the existing flame retardant methods often require complex synthesis steps and expensive raw materials, which increases the production cost. Summary of the Invention

[0004] Aiming at the problems existing in the above-mentioned prior art, based on the disadvantages of existing flame retardant hydrogels, such as poor mechanical properties, complex methods, high costs, and being not environmentally friendly, a preparation method of a highly self-recovering biomass flame retardant hydrogel is provided. The hydrogel is prepared by introducing montmorillonite and biomass phytic acid: Biomass phytic acid is grafted onto the acrylamide network, and the cellulose network is crosslinked by a silane solution and grafted with montmorillonite to form a double-network hydrogel together. There are acid source, gas source, carbon source, and Si, Al plasma components, which can improve the flame retardancy while enhancing the mechanical properties.

[0005] A preparation method of a highly self-recovering biomass flame-retardant hydrogel is carried out according to the following steps:

[0006] I. Disperse montmorillonite and cellulose in deionized water, centrifuge after ultrasonic treatment, and take the supernatant to obtain a dispersion;

[0007] II. Mix the silane solution and deionized water and stir to obtain a silane hydrolysis solution, then add an aqueous solution of phytic acid and stir, control the temperature at 70-75 °C, and react for 3 h to obtain a phytic acid-silane hydrolysis solution;

[0008] III. Mix the dispersant, cosolvent and the dispersion obtained in step I, stir until clear, add a surfactant and stir evenly, then add acrylamide and stir until dissolved evenly to prepare a precursor solution;

[0009] The cosolvent is a sodium salt;

[0010] The dispersant is triethylhexyl phosphate, sodium dodecyl sulfate or methylpentanol;

[0011] The surfactant is octadecyl methacrylate or cetyl methacrylate;

[0012] IV. Mix cellulose, the phytic acid-silane hydrolysis solution obtained in step II and the precursor solution obtained in step III, add an initiator, put it into a mold, control the reaction temperature at 60-63 °C, and react for 24 h to prepare the highly self-recovering biomass flame-retardant hydrogel;

[0013] Among them, the initiator is a persulfate initiator, and the dosage ratio of cellulose, phytic acid-silane hydrolysis solution, precursor solution and initiator is (2-6):6:14:0.01.

[0014] Among them, the cellulose used in step I and step IV is CNF prepared by TEMPO oxidation method.

[0015] Further, the silane solution in step II is any one of silane compounds substituting silicon element for hydrogen element, such as dimethyldiethoxysilane, tetraethyl orthosilicate and aminopropyltrimethoxysilane.

[0016] Further, the cosolvent in step III is a sodium salt, such as sodium benzoate, sodium salicylate and sodium chloride.

[0017] Further, the initiator in step IV is a persulfate initiator, such as potassium persulfate, sodium persulfate and ammonium persulfate.

[0018] Advantages of the present invention:

[0019] (1) Environmentally friendly and harmless: The present invention does not use traditional flame retardants that have a negative impact on the environment, but instead adds biomass phytic acid and montmorillonite. Phytic acid is a non-toxic and harmless environmentally friendly material with advantages such as being renewable and environmentally friendly, and it will not have a negative impact on the environment and human health, meeting the current development trend of green chemistry; montmorillonite is an inexpensive and biocompatible natural layered clay mineral. Therefore, the hydrogel of the present invention is more suitable for fields with high environmental protection requirements such as electronic devices and building materials.

[0020] (2) Performance improvement: The hydrogel of the present invention is cross-linked by a physical and chemical double network, and montmorillonite is introduced to increase the toughness and tensile strength of the hydrogel by 2.34 times and 1.15 times respectively compared to the blank sample, improving the problem of insufficient mechanical properties of the hydrogel. At the same time, due to the reversibility of physical cross-linking, the hydrogel can regenerate stronger cross-links in the orientation direction after stretching and has significant self-recovery performance under high strain, with a self-recovery efficiency as high as 106.8%. In the present invention, there are phytic acid (acid source and carbon source), acrylamide (gas source and carbon source), and various ionic components, and the hydrogel releases water when heated. When burning, the nitrogen and carbon elements in the hydrogel and the phosphorus element in phytic acid have a flame retardant synergistic effect to form a flame retardant system. At the same time, montmorillonite burns to form a dense carbon layer, and phytic acid promotes the carbon layer to be more dense and continuous, blocking the transfer of oxygen and heat to the interior of the material, which can improve the flame retardancy and thermal stability to a certain extent and simultaneously enhance the mechanical properties of the hydrogel. This multifunctional flame retardant mechanism ensures that the hydrogel can be used as a promising bio-based flame retardant material, providing a reference for safe and reliable applications in extreme environments. At the same time, this is in sharp contrast to the prior art of improving the flame retardant performance of hydrogels by adding flame retardants, but often sacrificing the mechanical properties of the hydrogels. This means that the hydrogel of the present invention has better durability and safety, so it has greater advantages in some special applications such as drug delivery and tissue engineering in high-temperature environments, thus enhancing its economic value.

[0021] (3) Simplified steps: The preparation method of the present invention is simple, avoiding the complex synthesis steps and expensive raw materials in the prior art, thereby reducing the production cost and having a broader application prospect.

[0022] The hydrogel prepared by the present invention is used in the field of flame retardancy of polymer materials. Description of the Drawings

[0023] Figure 1 Comparison chart of the mechanical property test results of the hydrogels prepared in the examples and comparative examples;

[0024] Figure 2Performance test result diagrams of the hydrogel prepared in Example 1 for the first and fifth of five consecutive loading-unloading cycles at a constant strain of 1000%, and for another loading-unloading cycle at a constant strain of 1000% after leaving the loaded spline to stand at room temperature for 300 minutes;

[0025] Figure 3 Comparison diagram of the recovery rate ζ(%) of the hydrogels prepared for the examples and comparative examples;

[0026] Figure 4 Photos of the test results of the flame retardancy of the hydrogels prepared in Example 3 and Comparative Example 1;

[0027] Figure 5 Schematic diagram of the Raman results of the char residue after combustion of the hydrogel prepared in Example 3. Detailed implementation manners

[0028] Detailed implementation manner 1: A preparation method of a highly self-recovering biomass flame-retardant hydrogel in this implementation manner is specifically carried out according to the following steps:

[0029] I. Disperse montmorillonite and cellulose in deionized water, centrifuge after ultrasonic treatment, and take the supernatant to obtain a dispersion;

[0030] II. Mix the silane solution with deionized water and stir to obtain a silane hydrolysis solution, then add an aqueous solution of phytic acid and stir, control the temperature at 70 - 75 °C, and react for 3 h to obtain a phytic acid-silane hydrolysis solution;

[0031] III. Mix the dispersant, cosolvent with the dispersion obtained in step I, stir until clear, add a surfactant and stir evenly, then add acrylamide and stir until dissolved evenly to prepare a precursor solution;

[0032] The cosolvent is a sodium salt;

[0033] The dispersant is triethylhexyl phosphate, sodium dodecyl sulfate or methylpentanol;

[0034] The surfactant is octadecyl methacrylate or cetyl methacrylate;

[0035] IV. Mix cellulose, the phytic acid-silane hydrolysis solution obtained in step II with the precursor solution obtained in step III, add an initiator, put it into a mold, control the reaction temperature at 60 - 63 °C, and react for 24 h to prepare the highly self-recovering biomass flame-retardant hydrogel;

[0036] Wherein the initiator is a persulfate initiator, and the dosage ratio of cellulose, phytic acid-silane hydrolysis solution, precursor solution to the initiator is (2 - 6):6:14:0.01.

[0037] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that: the mass ratio of the montmorillonite, cellulose and deionized water in Step 1 is (1-2):(1-2):100. Others are the same as Specific Embodiment 1.

[0038] Specific Embodiment 3: The difference between this embodiment and Specific Embodiment 1 or 2 is that: the dosage of the silane solution in Step 2 is 10-12% of the mass of deionized water. Others are the same as Specific Embodiment 1 or 2.

[0039] Specific Embodiment 4: The difference between this embodiment and any one of Specific Embodiments 1 to 3 is that: the silane solution in Step 2 is any one of the silane compounds substituting silicon element for hydrogen element. Others are the same as any one of Specific Embodiments 1 to 3.

[0040] Specific Embodiment 5: The difference between this embodiment and any one of Specific Embodiments 1 to 4 is that: the mass fraction of phytic acid in the phytic acid aqueous solution in Step 2 is 10-12%. Others are the same as any one of Specific Embodiments 1 to 4.

[0041] Specific Embodiment 6: The difference between this embodiment and any one of Specific Embodiments 1 to 5 is that: the mass ratio of the silane hydrolysis solution to the phytic acid aqueous solution in Step 2 is 1:(1-1.5). Others are the same as any one of Specific Embodiments 1 to 5.

[0042] Specific Embodiment 7: The difference between this embodiment and any one of Specific Embodiments 1 to 6 is that: the dosage of the dispersant in Step 3 in the phytic acid aqueous solution is 5-8% of the mass of the dispersion liquid. Others are the same as any one of Specific Embodiments 1 to 6.

[0043] Specific Embodiment 8: The difference between this embodiment and any one of Specific Embodiments 1 to 7 is that: the dosage ratio of the co-solvent to the dispersion liquid in Step 3 in the phytic acid aqueous solution is (0.007-0.01) mol:60 g. Others are the same as any one of Specific Embodiments 1 to 7.

[0044] Specific Embodiment 9: The difference between this embodiment and any one of Specific Embodiments 1 to 8 is that: the dosage ratio of the surfactant to the dispersion liquid in Step 3 in the phytic acid aqueous solution is (0.001-0.002) mol:60 g. Others are the same as any one of Specific Embodiments 1 to 8.

[0045] Specific Embodiment 10: The difference between this embodiment and any one of Specific Embodiments 1 to 9 is that: the dosage ratio of acrylamide to the dispersion liquid in Step 3 in the phytic acid aqueous solution is (0.4-0.5) mol:60 g. Others are the same as any one of Specific Embodiments 1 to 9.

[0046] The content of the present invention is not limited to the content of the above embodiments, and the combination of one or several specific embodiments can also achieve the purpose of the invention.

[0047] Example 1:

[0048] A preparation method of a highly self-recoverable biomass flame-retardant hydrogel is specifically carried out according to the following steps:

[0049] I. Disperse 1 g of montmorillonite and 1 g of cellulose in 100 g of deionized water, stir at room temperature, then ultrasonicate for 20 min, and then centrifuge for 20 min. Take the supernatant to obtain a dispersion.

[0050] II. Mix 2.97 g of dimethyldiethoxysilane with 26.69 g of deionized water and stir to obtain a silane hydrolysis solution. Then add an aqueous phytic acid solution and stir. Control the temperature at 70 °C and react for 3 h to obtain a phytic acid silane hydrolysis solution. The aqueous phytic acid solution is prepared by mixing 2 g of phytic acid and 18 g of deionized water.

[0051] III. Add 3 g of the dispersant sodium dodecyl sulfate and 1.22 g of the co-solvent sodium chloride to 60 g of the dispersion obtained in step I and mix. Stir at room temperature until clear. Add 0.93 g of the surfactant octadecyl methacrylate and stir for 2 h. Then add 26 g of acrylamide monomer and stir until dissolved uniformly to prepare a precursor solution.

[0052] IV. Mix 2 g of cellulose, 6 g of the phytic acid silane hydrolysis solution obtained in step II, and 14 g of the precursor solution obtained in step III. Add 0.01 g of the initiator potassium persulfate, put it into a mold, and react at 60 °C for 24 h to prepare the highly self-recoverable biomass flame-retardant hydrogel.

[0053] Example 2:

[0054] A preparation method of a highly self-recoverable biomass flame-retardant hydrogel is specifically carried out according to the following steps:

[0055] I. Disperse 1 g of montmorillonite and 1 g of cellulose in 100 g of deionized water, stir at room temperature, then ultrasonicate for 20 min, and then centrifuge for 20 min. Take the supernatant to obtain a dispersion.

[0056] II. Mix 2.97 g of dimethyldiethoxysilane with 26.69 g of deionized water and stir to obtain a silane hydrolysis solution. Then add an aqueous phytic acid solution and stir. Control the temperature at 70 °C and react for 3 h to obtain a phytic acid silane hydrolysis solution. The aqueous phytic acid solution is prepared by mixing 2 g of phytic acid and 18 g of deionized water.

[0057] III. Add 3 g of the dispersant sodium dodecyl sulfate and 1.22 g of the co-solvent sodium chloride to 60 g of the dispersion obtained in Step I, mix them, stir at room temperature until clear, add 0.93 g of the surfactant octadecyl methacrylate and stir for 2 h, then add 26 g of acrylamide monomer and stir until dissolved evenly to prepare a precursor solution;

[0058] IV. Mix 4 g of cellulose, 6 g of the phytic acid-silane hydrolysis solution obtained in Step II and 14 g of the precursor solution obtained in Step III, add 0.01 g of the initiator potassium persulfate, place it in a mold, and react at 60 °C for 24 h to prepare the described high self-recovery biomass flame-retardant hydrogel.

[0059] Example 3:

[0060] A preparation method of a high self-recovery biomass flame-retardant hydrogel is specifically carried out according to the following steps:

[0061] I. Disperse 1 g of montmorillonite and 1 g of cellulose in 100 g of deionized water, stir at room temperature, then ultrasonicate for 20 min, and then centrifuge for 20 min, and take the supernatant to obtain a dispersion;

[0062] II. Mix 2.97 g of dimethyldiethoxysilane with 26.69 g of deionized water and stir to obtain a silane hydrolysis solution, then add a phytic acid aqueous solution and stir, control the temperature at 70 °C, and react for 3 h to obtain a phytic acid-silane hydrolysis solution; the phytic acid aqueous solution is prepared by mixing 2 g of phytic acid and 18 g of deionized water;

[0063] III. Add 3 g of the dispersant sodium dodecyl sulfate and 1.22 g of the co-solvent sodium chloride to 60 g of the dispersion obtained in Step I, mix them, stir at room temperature until clear, add 0.93 g of the surfactant octadecyl methacrylate and stir for 2 h, then add 26 g of acrylamide monomer and stir until dissolved evenly to prepare a precursor solution;

[0064] IV. Mix 6 g of cellulose, 6 g of the phytic acid-silane hydrolysis solution obtained in Step II and 14 g of the precursor solution obtained in Step III, add 0.01 g of the initiator potassium persulfate, place it in a mold, and react at 60 °C for 24 h to prepare the described high self-recovery biomass flame-retardant hydrogel.

[0065] Comparative Example 1:

[0066] The preparation method of the hydrogel in this comparative example:

[0067] 1. Mix 2.97 g of dimethyldiethoxysilane with 26.69 g of deionized water and stir to obtain a silane hydrolysis solution. Then add an aqueous phytic acid solution and stir. Control the temperature at 70 °C and react for 3 h to obtain a phytic acid-silane hydrolysis solution. The aqueous phytic acid solution is prepared by mixing 2 g of phytic acid and 18 g of deionized water.

[0068] 2. Add 3 g of the dispersant sodium dodecyl sulfate and 1.22 g of the co-solvent sodium chloride to 60 g of deionized water and mix. Stir at room temperature until clear. Add 0.93 g of the surfactant octadecyl methacrylate and stir for 2 h. Then add 26 g of acrylamide monomer and stir until dissolved uniformly to prepare a precursor solution.

[0069] 4. Mix 2 g of cellulose, 6 g of the phytic acid-silane hydrolysis solution obtained in Step 1, and 14 g of the precursor solution obtained in Step 2. Add 0.01 g of the initiator potassium persulfate, place it in a mold, and react at 60 °C for 24 h to prepare a hydrogel.

[0070] Performance testing:

[0071] Mechanical properties: The tensile property test was carried out according to the ASTM D638 standard, and the tensile speed was 20 mm / min. The results of the mechanical property test are as Figure 1 .

[0072] As Figure 1 can be seen, all component hydrogels have good strength > 369 kPa and high fracture strain > 1700%. The toughness and tensile strength of Example 1 are as high as 4819 kJ / m3 and 50 kPa, which are increased by 2.34 times and 1.15 times compared with Comparative Example 1. It shows that when the hydrogel is stretched, due to the interaction between the cations in montmorillonite and carboxyl groups, a large amount of energy is consumed, thereby improving the mechanical properties of the material. Therefore, montmorillonite can significantly improve the strength and toughness of cellulose hydrogels. With the increase of cellulose concentration, the fracture strength, toughness and Young's modulus of the hydrogel gradually decrease, but are all higher than that of Comparative Example 1; at the same time, the fracture elongation gradually increases. It shows that the increase of cellulose content provides more -COOH groups to bind with the cations in montmorillonite, so that the network density of the hydrogel is larger and the fracture strain is higher. While the mechanics and toughness decrease with the addition of cellulose, indicating that the hydrogel with a higher cellulose content has a higher cross-linking density, which will limit the movement of polymer chains in the hydrogel.

[0073] Self-recovery performance: After the gel sample was subjected to five consecutive loading-unloading cycles at a constant strain of 1000%, the hydrogel was left standing at room temperature for 300 minutes, and then a loading-unloading cycle was carried out again at a constant strain of 1000%. The recovery rate ζ (%) can be calculated according to the ratio of the tensile modulus in the first loading cycle after standing to the first tensile modulus before standing. AsFigure 2 and Figure 3 It can be seen that for the restored Example 1 (ζ2 = 106.8% > 100%) and Example 2 (ζ3 = 101.8% > 100%), compared with the original sample, both the stress and modulus exceed the original sample, showing excellent self-recovery ability. The results show that the stiffness and toughness of the prepared hydrogel can be restored to a level exceeding that of the original spline within 300 min at room temperature. The residual strain of the hydrogel completely disappears, and the size is completely restored, showing a typical muscle enhancement effect. This is because after continuous loading-unloading cycles, some physical cross-links are broken, accompanied by the orientation of polymer chains in the axial direction. After rest, some physical cross-links are quickly rebuilt and fix the polymer chains in the oriented direction, thus improving the stiffness and toughness of the hydrogel.

[0074] Flame retardant performance: In the open flame ignition experiment, the sample was ignited with an alcohol burner for 60 s and then removed from the flame. Finally, the combustibility test process and results were recorded by a digital camera. The flame retardant performance test results are as Figure 4 .

[0075] From Figure 4 In the combustion experiment, a hydrogel with a length of 2 cm and a thickness of only 1 mm was ignited under an alcohol lamp for 1 min. It can be seen that for all samples, the flame does not spread to the upper part of the sample during the whole combustion process, and no molten droplets appear. Moreover, when the hydrogel is removed from the flame, it will self-extinguish immediately because of the large evaporation enthalpy of water, which prevents the material from reaching the ignition point. In addition, Example 3 retains a longer length after combustion, showing better flame retardancy. This can be attributed to the increase in the formation of coke due to the addition of montmorillonite and the increase in cellulose content, which acts as a thermal barrier.

[0076] Figure 5 The graphitization degree of the residual carbon was analyzed by Raman spectroscopy. Two representative peaks at 1322 cm-1 and 1550 cm-1 correspond to the D and G peaks respectively. Example 3 shows an extremely low ID / IG ratio of 1.33, indicating that the carbon residue is denser and the degree of carbonization is better. It shows that the invention can effectively form a densified carbon layer to block heat transfer and improve the flame retardant performance.

Claims

1. A method for preparing a highly self-recovering biomass flame-retardant hydrogel, characterized in that The method is specifically carried out in the following steps:

1. Disperse montmorillonite and cellulose in deionized water, centrifuge after ultrasonication, and take the supernatant to obtain a dispersion; 2. Mixing the silane solution with deionized water to obtain a silane hydrolysis solution, and then adding the phytic acid aqueous solution and mixing, controlling the temperature to 70-75° C., reacting for 3 hours, and obtaining a phytic acid silane hydrolysis solution; 3. Mix the dispersant and the cosolvent with the dispersion obtained in step 1, stir until clear, add a surfactant and stir evenly, then add acrylamide and stir until dissolved evenly, to prepare a precursor solution; The cosolvent is a sodium salt; The dispersant is triethylhexyl phosphoric acid, sodium lauryl sulfate or methyl amyl alcohol; The surfactant is octadecyl methacrylate or hexadecyl methacrylate; Fourth, the cellulose, the phytic acid silane hydrolyzed solution obtained in step 2 and the precursor solution obtained in step 3 are mixed, an initiator is added, and the mixture is placed in a mold, the reaction temperature is controlled to be 60-63° C., and the reaction is performed for 24 hours to prepare the highly self-healing biomass flame-retardant hydrogel; The initiator is a persulfate initiator, and the dosage ratio of cellulose, phytic acid silane hydrolysis solution, precursor solution and initiator is (2-6):6:14:0.

01.

2. The method for preparing a highly self-healing biomass flame-retardant hydrogel according to claim 1, characterized in that The mass ratio of montmorillonite, cellulose and deionized water in step 1 is (1-2):(1-2):

100.

3. The method for preparing a highly self-healing biomass flame-retardant hydrogel according to claim 1, characterized in that The amount of the silane solution used in step 2 is 10-12% of the mass of deionized water.

4. The method for preparing a highly self-recovering biomass flame-retardant hydrogel according to claim 1, characterized in that The silane solution in step 2 is any one of silane compounds that can replace silicon and hydrogen.

5. The method for preparing a highly self-healing biomass flame-retardant hydrogel according to claim 1, characterized in that In step 2, the mass fraction of phytic acid in the phytic acid aqueous solution is 10-12%.

6. The method for preparing a highly self-healing biomass flame-retardant hydrogel according to claim 1, characterized in that In step 2, the mass ratio of the silane hydrolysis solution to the phytic acid aqueous solution is 1:(1-1.5).

7. The method for preparing a highly self-healing biomass flame-retardant hydrogel according to claim 1, characterized in that The dosage of the dispersant in step 3 is 5-8% of the mass of the dispersion.

8. The method for preparing a highly self-recovering biomass flame-retardant hydrogel according to claim 1, characterized in that The dosage ratio of the co-solvent to the dispersion liquid in step 3 is (0.007-0.01) mol: 60 g.

9. The method for preparing a highly self-healing biomass flame-retardant hydrogel according to claim 1, characterized in that In the step 3, the dosage ratio of the surfactant to the dispersion is (0.001-0.002) mol: 60 g.

10. The method for preparing a highly self-healing biomass flame-retardant hydrogel according to claim 1, characterized in that In step 3, the usage ratio of acrylamide to dispersion liquid is (0.4-0.5) mol: 60 g.

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