Dehydrogenation porous structure ceramic fire-retardant material and preparation method and application thereof

Abstract

The invention belongs to the field of ceramic flame-retardant materials, and particularly provides a dehydrogenation porous structure ceramic flame-retardant material and a preparation method and application thereof. Comprising the following steps: 1) uniformly mixing a quaternary ammonium base solution, cellulose and a solvent, then adding modified polysaccharide and an amino acid derivative, continuously mixing, then filling inert gas for foaming, then transferring into a solidification liquid for shaping, and washing to obtain a cellulose-based foam material; (2) soaking a cellulose-based foam material into the modification liquid, carrying out microwave heating treatment, then taking out, washing and drying to obtain a template material; and 3) uniformly mixing the ceramic powder, water, ethanol, a binder, a rheological agent, a dispersant and a plasticizer to prepare ceramic slurry, immersing the template material into the prepared ceramic slurry, uniformly wrapping the template material with the ceramic slurry, extruding to discharge redundant slurry, and finally drying and sintering to obtain the ceramic material. The porous structure ceramic fire-retardant material prepared by the invention has the advantages of high strength and good fire-retardant performance.

Description

Technical Field

[0001] The present application belongs to the technical field of ceramic flame retardant materials, and in particular relates to a hydrogen-eliminating porous structure ceramic fire retardant material and its preparation method and application. Background Art

[0002] The rich pore structure of porous ceramics endows them with a variety of excellent properties, such as high permeability, large specific surface area, low density, low thermal conductivity, sound absorption, and high-temperature and corrosion resistance. As a result, porous ceramics are widely used in filtration and separation, catalyst supports, sound absorption, and thermal insulation. The uses of porous ceramics are determined by their pore structure. For use as thermal insulation, flame retardancy, and fireproofing materials, porous ceramics must exhibit high thermal insulation, flame retardancy, heat insulation, and fireproofing properties.

[0003] There are many methods for preparing porous ceramics. Different preparation methods are selected according to the performance requirements of the material in order to achieve good expected results. In recent years, the more mature methods for preparing porous ceramics mainly include particle stacking method, template method, foaming method, gel casting method, organic foam impregnation method, freeze drying method and mixed pore formation method. Among them, the organic foam impregnation method uses the special structure of the three-dimensional open-pore mesh skeleton of the organic foam as a template to evenly coat the prepared ceramic slurry on the organic foam, then remove the excess ceramic slurry on the organic foam, and then sinter to remove the organic foam to obtain the porous ceramic preparation process. It has excellent flame retardant, fire retardant and thermal insulation properties.

[0004] Currently, widely used organic foams include polyurethane, cellulose, wood, polyvinyl chloride, and polystyrene. Porous ceramics prepared by organic foam impregnation can be finely controlled by selecting different templates to create porous ceramics with both pore structure and microstructure, making the process simple and convenient. However, the organic foam impregnation method can produce porous ceramics with large deformation during sintering, resulting in low strength, structural collapse, and pore size and shape limited by the shape of the organic foam.

[0005] In addition, while porous ceramics can provide good protection during fire accidents, they are unable to meet the protection requirements of existing porous ceramics due to the wide flammability range, extremely low ignition energy, rapid diffusion, high combustion temperature, and the generation of a large number of free radicals in such a complex, high-temperature combustion environment. Therefore, the development of high-performance porous ceramic materials is urgently needed. Summary of the Invention

[0006] In view of the above problems, in order to further improve the fire-retardant and heat-insulating protection performance of porous ceramics in hydrogen combustion environments, the present application provides a hydrogen-removing porous structure ceramic fire-retardant material and its preparation method and application.

[0007] This application first provides a method for preparing a hydrogen-absorbing porous structure ceramic fire-retardant material, comprising the following steps: 1) A quaternary ammonium solution, cellulose, and a solvent are mixed evenly, and then modified polysaccharides and amino acid derivatives are added and continued to mix. Then, an inert gas is introduced to foam the mixture, and the mixture is transferred to a coagulation liquid for setting. After washing, a cellulose-based foam material is obtained. 2) Deionized water, N-alkyl acrylamide, and fatty acid iron salt are uniformly mixed to prepare a pre-fluid, and aluminum sulfate, urea, and unsaturated dicarboxylic acid are slowly added to the pre-fluid to prepare a modifying solution. The cellulose-based foam material is then immersed in the modifying solution, subjected to microwave heating, and then removed, washed, and dried to obtain a template material. 3) Ceramic powder, water, ethanol, binder, rheological agent, dispersant and plasticizer are mixed evenly to prepare ceramic slurry. Then the template material is immersed in the prepared ceramic slurry. After the ceramic slurry evenly wraps the template material, the excess slurry is squeezed out and finally dried and sintered to obtain the product.

[0008] Furthermore, in step 1), the mass volume ratio of the quaternary ammonium solution, cellulose, and solvent is (65-70) mL: (10-15) g: (20-30) mL; And / or, in step 1), the solvent is one of DMF, DMSO, and DMAC; And / or, in step 1), the amino acid derivative is one or more of phthaloylglycine, palmitoylglycine, and N-benzoylglycine.

[0009] Furthermore, the preparation method of the modified polysaccharide comprises the following steps: a) taking a flaxseed gum solution, adding polysaccharide and casein, stirring until fully dissolved, and adjusting the pH to a weakly alkaline pH to obtain a mixed solution; b) adding sodium tetraborate and β-mercaptoethanol to the mixed solution, reacting at 85-95° C. for 60-80 minutes to obtain a modified polysaccharide.

[0010] Furthermore, the polysaccharide is one or more of konjac gum, pectin, and xanthan gum.

[0011] Furthermore, in step 2), the mass ratio of deionized water, N-alkyl acrylamide, and fatty acid salt is 1:(0.1-0.15):(0.05-0.1); And / or, in step 2), the fatty acid iron salt is one or more of iron stearate, iron palmitate, iron stearate, and iron oleate; And / or, in step 2), the N-alkyl acrylamide is one or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, and N-octadecyl acrylamide; And / or, the unsaturated dicarboxylic acid is one of fumaric acid, maleic acid, and glutaconic acid.

[0012] Furthermore, in step 3), the ceramic powder includes aluminum oxide, zirconium oxide, and magnesium oxide; And / or, in step 3), the binder is one of polyvinyl alcohol, sodium carboxymethyl cellulose, polyethyleneimine, silica sol, aluminum phosphate, borate, sodium silicate, and potassium silicate; And / or, in step 3), the rheological agent is one of carboxymethyl cellulose, hydroxyethyl cellulose, bentonite, and kaolin; And / or, in step 3), the dispersant is one of citric acid, sodium polymetaphosphate, polyacrylamide, polyvinyl alcohol, and polyvinyl ether; And / or, in step 3), the plasticizer is one of talc powder, mica powder, and dioctyl phthalate.

[0013] Furthermore, the coagulation liquid comprises the following raw materials in weight fractions: 100-150 parts of water, 5-10 parts of sulfuric acid, 0.15-0.2 parts of carrageenan, 0.8-1.2 parts of cyclodextrin derivative, 1-3 parts of nickel nitrate, and 2-5 parts of manganese nitrate.

[0014] Furthermore, the cyclodextrin derivative is prepared by a method comprising the following steps: Ⅰ) Add imidazole-1-acetic acid to dichloromethane and stir until completely dissolved, then add oxalyl chloride, heat under reflux for reaction, and remove the solvent to obtain imidazole-1-acetyl chloride; II) Dissolve cyclodextrin in DMF, add triethylamine and mix well, then slowly add DMF solution containing imidazole-1-acetyl chloride into the system, wash with acetone after sufficient reaction, then redissolve with deionized water and dry to obtain the product.

[0015] Furthermore, the cyclodextrin is one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

[0016] The present application also provides a hydrogen-absorbing porous structure ceramic fire-retardant material, which is prepared using the above-mentioned preparation method.

[0017] The present application also provides an application of a hydrogen-eliminating porous structure ceramic fire-retardant material, and the hydrogen-eliminating porous structure ceramic fire-retardant material prepared by the above preparation method is used for building fireproof panels, industrial kiln insulation layers, and aviation insulation parts.

[0018] Compared with the prior art, this application has the following beneficial effects: 1. This application uses a quaternary ammonium base and a solvent to dissolve cellulose, forming a heterogeneous cellulose dissolution system. Using inert gas foaming, a three-dimensional pore structure can be prepared. Furthermore, the addition of modified polysaccharides and amino acid derivatives can help enhance the mechanical properties of the cellulose three-dimensional network structure, thereby improving the subsequent slurrying and sintering properties of ceramic slurries, inhibiting the occurrence of undesirable defects such as pore collapse and deformation, and increasing the skeleton strength and toughness of porous ceramics.

[0019] 2. The present application performs an impregnation modification treatment on the cellulose-based foam material. On the one hand, aluminum ions and unsaturated dicarboxylic acids can be adsorbed inside the pores of the material in the presence of water and urea to form a three-dimensional network of aluminum ion organic ligands, which can form a porous foam alumina structure during the sintering process, further improving the skeleton strength of the porous structure. On the other hand, fatty acid iron salts form active doping on alumina after sintering, and iron atoms can effectively eliminate free radicals generated during the combustion process of hydrogen-containing combustibles through chain reactions. Moreover, since iron atoms are prone to agglomeration and aggregate into three-dimensional particles and become inactivated, porous foam alumina can effectively inhibit the agglomeration of iron atoms, and the amount of fatty acid iron salts added can be increased, thereby increasing the doping concentration of iron and obtaining a better free radical elimination effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a SEM schematic diagram of a sample of a hydrogen-absorbing porous ceramic fire-retardant material according to Example 1 of the present application; Figure 2 This is a SEM diagram of a sample of a hydrogen-absorbing porous ceramic fire-retardant material according to Example 2 of the present application; Figure 3 This is a SEM diagram of a sample of hydrogen-absorbing porous ceramic fire-retardant material for the control group of this application; Figure 4 This is a SEM schematic diagram of the porous foamed alumina formed on the porous structure surface of the sample of the hydrogen-scavenging porous ceramic fire-retardant material of Example 2 of the present application; Figure 5 This is a schematic diagram of the free radical spectrum detection data of the hydrogen-containing combustible gas flame combustion of the hydrogen-scavenging porous structure ceramic fire-retardant material in this application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] After a large number of experimental studies, this application addresses the shortcomings of traditional cellulose porous templates and constructs a cellulose-based foam material through a heterogeneous dissolution system. It also introduces modified polysaccharides and amino acid derivatives as well as aluminum ion organic ligands to enhance the strength of the porous structure skeleton. In addition, the introduction of an appropriate amount of iron atoms can effectively eliminate free radicals and achieve better fire retardant and heat insulating properties.

[0023] Specifically, the present application provides a method for preparing a hydrogen-absorbing porous structure ceramic fire-retardant material, comprising the following steps: 1) A quaternary ammonium solution, cellulose, and a solvent are mixed evenly, and then modified polysaccharides and amino acid derivatives are added and continued to mix. Then, an inert gas is introduced to foam the mixture, and the mixture is transferred to a coagulation liquid for setting. After washing, a cellulose-based foam material is obtained. 2) Deionized water, N-alkyl acrylamide, and fatty acid iron salt are uniformly mixed to prepare a pre-fluid, and aluminum sulfate, urea, and unsaturated dicarboxylic acid are slowly added to the pre-fluid to prepare a modifying solution. The cellulose-based foam material is then immersed in the modifying solution, subjected to microwave heating, and then removed, washed, and dried to obtain a template material. 3) Ceramic powder, water, ethanol, binder, rheological agent, dispersant and plasticizer are mixed evenly to prepare ceramic slurry. Then the template material is immersed in the prepared ceramic slurry. After the ceramic slurry evenly wraps the template material, the excess slurry is squeezed out and finally dried and sintered to obtain the product.

[0024] Furthermore, in step 1), the mass volume ratio of the quaternary ammonium solution, cellulose, and solvent is (65-70) mL: (10-15) g: (20-30) mL; And / or, in step 1), the solvent is one of DMF, DMSO, and DMAC; And / or, in step 1), the amino acid derivative is one or more of phthaloylglycine, palmitoylglycine, and N-benzoylglycine.

[0025] In some specific embodiments, in step 1), the mass volume ratio of the quaternary ammonium solution, cellulose, and solvent can be 65 mL:10 g:20 mL, 65 mL:12 g:20 mL, 65 mL:15 g:20 mL, 65 mL:10 g:25 mL, 65 mL:10 g:30 mL, 65 mL:12 g:25 mL, 65 mL:12 g:30 mL, 65 mL:15 g:25 mL, 65 mL:15 g:30 mL, 70 mL:10 g:20 mL, 70 mL:12 g:20 mL, 70 mL:15 g:20 mL, 70 mL:12 g:30 mL, and 70 mL:15 g:30 mL. Generally, when the mass volume ratio of the quaternary ammonium solution, cellulose, and solvent is 70 mL:12 g:20 mL, better experimental results can be obtained.

[0026] In some specific embodiments, the quaternary ammonium base solution is one or more of tetramethylammonium hydroxide solution, tetraethylammonium hydroxide solution, tetrapropylammonium hydroxide solution, and tetrabutylammonium hydroxide solution. Generally, better experimental results can be obtained when the quaternary ammonium base solution is tetrabutylammonium hydroxide solution.

[0027] In some specific embodiments, the cellulose is natural cellulose. More preferably, the natural cellulose is one or more of bamboo pulp, wood pulp, cotton pulp, mushroom grass fiber, and hemp fiber. Generally, the experimental effect is better when the cellulose is cotton pulp.

[0028] In some specific embodiments, better experimental results can be obtained when the solvent is DMSO and the amino acid derivative is N-benzoylglycine.

[0029] In some specific embodiments, the mass ratio of cellulose, modified polysaccharide, and amino acid derivative can be 1:0.1:0.05, 1:0.12:0.05, 1:0.135:0.05, 1:0.15:0.05, 1:0.12:0.06, 1:0.135:0.06, 1:0.16:0.06, 1:0.12:0.07, 1:0.135:0.07, 1:0.15:0.07, 1:0.12:0.075, 1:0.135:0.075, and 1:0.15:0.075. Generally, when the mass ratio of cellulose, modified polysaccharide, and amino acid derivative is 1:0.15:0.06, better experimental results can be obtained.

[0030] Furthermore, the preparation method of the modified polysaccharide comprises the following steps: a) taking a flaxseed gum solution, adding polysaccharide and casein, stirring until fully dissolved, and adjusting the pH to a weakly alkaline pH to obtain a mixed solution; b) adding sodium tetraborate and β-mercaptoethanol to the mixed solution, reacting at 85-95° C. for 60-80 minutes to obtain a modified polysaccharide.

[0031] Furthermore, the polysaccharide is one or more of konjac gum, pectin, and xanthan gum.

[0032] Furthermore, in step 2), the mass ratio of deionized water, N-alkyl acrylamide, and fatty acid salt is 1:(0.1-0.15):(0.05-0.1); And / or, in step 2), the fatty acid iron salt is one or more of iron stearate, iron palmitate, iron stearate, and iron oleate; And / or, in step 2), the N-alkyl acrylamide is one or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, and N-octadecyl acrylamide; And / or, the unsaturated dicarboxylic acid is one of fumaric acid, maleic acid, and glutaconic acid.

[0033] In some specific embodiments, when the polysaccharide is xanthan gum, the fatty acid iron salt is iron stearate, the N-alkyl acrylamide is N-hexadecyl acrylamide, and the unsaturated dicarboxylic acid is fumaric acid, better experimental results can be obtained.

[0034] In some specific embodiments, in step 2), the mass ratio of deionized water, N-alkyl acrylamide, and fatty acid salt can be 1:0.01:0.005, 1:0.013:0.005, 1:0.015:0.005, 1:0.012:0.008, 1:0.015:0.008, 1:0.013:0.01, or 1:0.015:0.01. Generally, a mass ratio of deionized water, N-alkyl acrylamide, and fatty acid salt of 1:0.015:0.008 can achieve better experimental results.

[0035] Furthermore, in step 3), the ceramic powder includes aluminum oxide, zirconium oxide, and magnesium oxide; And / or, in step 3), the binder is one of polyvinyl alcohol, sodium carboxymethyl cellulose, polyethyleneimine, silica sol, aluminum phosphate, borate, sodium silicate, and potassium silicate; And / or, in step 3), the rheological agent is one of carboxymethyl cellulose, hydroxyethyl cellulose, bentonite, and kaolin; And / or, in step 3), the dispersant is one of citric acid, sodium polymetaphosphate, polyacrylamide, polyvinyl alcohol, and polyvinyl ether; And / or, in step 3), the plasticizer is one of talc powder, mica powder, and dioctyl phthalate.

[0036] In some specific embodiments, under normal circumstances, the ceramic powder is composed of aluminum oxide, zirconium oxide, and magnesium oxide in a mass ratio of 1:1:0.2, the binder is sodium carboxymethyl cellulose, the rheological agent is bentonite, the dispersant is sodium polymetaphosphate, and the plasticizer is dioctyl phthalate.

[0037] In some specific embodiments, the solid content of the ceramic slurry can be 65%, 70%, 75%, or 80%. Generally, when the solid content of the ceramic slurry is 75%, better experimental results can be obtained.

[0038] Furthermore, the coagulation liquid comprises the following raw materials in weight fractions: 100-150 parts of water, 5-10 parts of sulfuric acid, 0.15-0.2 parts of carrageenan, 0.8-1.2 parts of cyclodextrin derivative, 1-3 parts of nickel nitrate, and 2-5 parts of manganese nitrate.

[0039] Furthermore, the cyclodextrin derivative is prepared by a method comprising the following steps: Ⅰ) Add imidazole-1-acetic acid to dichloromethane and stir until completely dissolved, then add oxalyl chloride, heat under reflux for reaction, and remove the solvent to obtain imidazole-1-acetyl chloride; II) Dissolve cyclodextrin in DMF, add triethylamine and mix well, then slowly add DMF solution containing imidazole-1-acetyl chloride into the system, wash with acetone after sufficient reaction, then redissolve with deionized water and dry to obtain the product.

[0040] Furthermore, the cyclodextrin is one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin. Example 1

[0041] The method for preparing the hydrogen-scavenging porous ceramic fire-retardant material of this embodiment includes the following steps: 1) 70 mL of a 50% by mass tetrabutylammonium hydroxide solution, 12 g of cotton pulp, and 30 g of DMSO were mixed evenly, and then 1.8 g of a modified polysaccharide and 0.72 g of an amino acid derivative were added and continued to mix. Nitrogen was then introduced for foaming, and the mixture was stirred continuously to uniformly fill the system with bubbles. Larger bubbles were removed by vacuuming, and then injected into a coagulation liquid through a rectangular nozzle for final shaping. After washing, a cellulose-based foam material was obtained. The coagulation solution includes the following raw materials by weight: 10 kg of water, 1 kg of sulfuric acid, 18 g of carrageenan, 100 g of carboxymethyl cyclodextrin, 250 g of nickel nitrate, and 400 g of manganese nitrate; 2) 10 kg of deionized water, 150 g of N-hexadecyl acrylamide, and 80 g of ferric stearate are uniformly mixed to prepare a pre-fluid, and then 300 g of aluminum sulfate, 150 g of urea, and 30 g of fumaric acid are slowly added to the pre-fluid to prepare a modifying solution. The cellulose-based foam material is then immersed in the modifying solution, subjected to microwave heating, and then removed, washed, and dried to obtain a template material; The preparation method of the modified polysaccharide comprises the following steps: a) Add 15 g of xanthan gum and 6 g of casein to 100 mL of a 20% solids flaxseed gum solution, stir until fully dissolved, and adjust the pH to 9.0 to obtain a mixed solution; b) adding 3 g of sodium tetraborate and 0.5 g of β-mercaptoethanol to the mixed solution, and reacting at 90° C. for 70 min to obtain a modified polysaccharide; 3) Take 500g of ceramic powder, 173.3g of water, 1.5g of polyethylene glycol, 2.5g of sodium carboxymethyl cellulose, 8g of bentonite, 4g of sodium polymetaphosphate, and 4g of dioctyl phthalate and mix them evenly to prepare a ceramic slurry. The solid content of the ceramic slurry is 75%. The ceramic powder is composed of aluminum oxide, zirconium oxide, and magnesium oxide in a mass ratio of 1:0.1:0.5. Then, the template material is immersed in the prepared ceramic slurry. After the ceramic slurry evenly wraps the template material, the excess slurry is squeezed out and then immersed in the ceramic slurry again. Centrifuge at 800r / min to obtain a green body, dry it at 60℃ for 24h, and then sinter it at 1550℃ for 3h.

[0042] The application of the hydrogen-eliminating porous structure ceramic fire-retardant material of this embodiment is to use the hydrogen-eliminating porous structure ceramic fire-retardant material in building fireproof panels. Example 2

[0043] The method for preparing the hydrogen-scavenging porous ceramic fire-retardant material of this embodiment includes the following steps: 1) 70 mL of a 50% by mass tetrabutylammonium hydroxide solution, 12 g of cotton pulp, and 30 g of DMSO were mixed evenly, and then 1.8 g of a modified polysaccharide and 0.72 g of an amino acid derivative were added and continued to mix. Nitrogen was then introduced for foaming, and the mixture was stirred continuously to uniformly fill the system with bubbles. Larger bubbles were removed by vacuuming, and then injected into a coagulation liquid through a rectangular nozzle for final shaping. After washing, a cellulose-based foam material was obtained. The coagulation solution includes the following raw materials by weight: 10 kg of water, 1 kg of sulfuric acid, 18 g of carrageenan, 100 g of carboxymethyl cyclodextrin, 250 g of nickel nitrate, and 400 g of manganese nitrate; The cyclodextrin derivative is prepared by a method comprising the following steps: Ⅰ) Add 0.05 mol of imidazole-1-acetic acid to 100 mL of dichloromethane and stir until completely dissolved. Then add 0.0875 mol of oxalyl chloride, heat under reflux, and remove the solvent to obtain imidazole-1-acetyl chloride; II) Dissolve 1 mmol of β-cyclodextrin in 20 mL of DMF, add 3 g of triethylamine and mix well. Then slowly add 15 mL of DMF solution containing 25 mmol of imidazole-1-acetyl chloride dropwise to the system. After sufficient reaction at 25°C, wash with acetone, redissolve in deionized water, and dry to obtain the product. 2) 10 kg of deionized water, 150 g of N-hexadecyl acrylamide, and 80 g of ferric stearate are uniformly mixed to prepare a pre-fluid, and then 300 g of aluminum sulfate, 150 g of urea, and 30 g of fumaric acid are slowly added to the pre-fluid to prepare a modifying solution. The cellulose-based foam material is then immersed in the modifying solution, subjected to microwave heating, and then removed, washed, and dried to obtain a template material; The preparation method of the modified polysaccharide comprises the following steps: a) Add 15 g of xanthan gum and 6 g of casein to 100 mL of a 20% solids flaxseed gum solution, stir until fully dissolved, and adjust the pH to 9.0 to obtain a mixed solution; b) adding 3 g of sodium tetraborate and 0.5 g of β-mercaptoethanol to the mixed solution, and reacting at 90° C. for 70 min to obtain a modified polysaccharide; 3) Take 500g of ceramic powder, 173.3g of water, 1.5g of polyethylene glycol, 2.5g of sodium carboxymethyl cellulose, 8g of bentonite, 4g of sodium polymetaphosphate, and 4g of dioctyl phthalate and mix them evenly to prepare a ceramic slurry. The solid content of the ceramic slurry is 75%. The ceramic powder is composed of aluminum oxide, zirconium oxide, and magnesium oxide in a mass ratio of 1:0.1:0.5. Then, the template material is immersed in the prepared ceramic slurry. After the ceramic slurry evenly wraps the template material, the excess slurry is squeezed out and then immersed in the ceramic slurry again. Centrifuge at 800r / min to obtain a green body, dry it at 60℃ for 24h, and then sinter it at 1550℃ for 3h.

[0044] The application of the hydrogen-eliminating porous structure ceramic fire-retardant material of this embodiment is to use the hydrogen-eliminating porous structure ceramic fire-retardant material in the heat insulation layer of an industrial furnace.

[0045] control group The preparation method of the hydrogen-eliminating porous structure ceramic fire-retardant material of the control group includes the following steps: 1) 70 mL of a 50% by mass tetrabutylammonium hydroxide solution, 12 g of cotton pulp, and 30 g of DMSO were mixed uniformly, and then nitrogen was introduced for foaming, with continuous stirring to uniformly fill the system with bubbles, and large bubbles were removed by vacuum. The mixture was then injected through a rectangular nozzle into a coagulation liquid for shaping, and washed to obtain a cellulose-based foam material; the coagulation liquid comprised the following raw materials by weight: 10 kg of water and 1 kg of sulfuric acid; 2) Take 500g of ceramic powder, 173.3g of water, 1.5g of polyethylene glycol, 2.5g of sodium carboxymethyl cellulose, 8g of bentonite, 4g of sodium polymetaphosphate, and 4g of dioctyl phthalate and mix them evenly to prepare a ceramic slurry. The solid content of the ceramic slurry is 75%. The ceramic powder is composed of aluminum oxide, zirconium oxide, and magnesium oxide in a mass ratio of 1:0.1:0.5. Then, the cellulose-based foam material is immersed in the prepared ceramic slurry. After the ceramic slurry evenly wraps the cellulose-based foam material, the excess slurry is squeezed out and then immersed in the ceramic slurry again. Centrifuge at 800r / min to obtain a green body, dry it at 60°C for 24h, and then sinter it at 1550°C for 3h.

[0046] Performance testing 1. Porosity determination The porous ceramic fire-retardant materials of Examples 1-2 and the control group were prepared into samples with a size of 50 mm × 50 mm × 50 mm. The bulk density and theoretical density of the samples, as well as the porosity, were tested. .in, is the bulk density of the sample, is the theoretical density of dense material. The results are shown in Table 1.

[0047] 2. Compression strength The porous ceramic fire-retardant materials of Examples 1-2 and the control group were prepared into samples with a size of Φ20mm×20mm. The compressive strength was tested using a universal electronic mechanical testing machine with a pressing head speed of 0.5mm / min. ,in, is the critical load, is the sample diameter, and the results are shown in Table 1.

[0048] Table 1 Ceramic material performance test data of Examples 1-2 and the control group

[0049] 3. Micromorphology test The porous ceramic fire-retardant materials of Examples 1-2 and the control group were taken and the micromorphology of the samples was observed using a scanning electron microscope. The results are as follows: Figure 1-3 As shown, Figure 1 For Example 1, Figure 2For Example 2, Figure 3 As the control group, Figure 4 This is the porous foamed alumina structure formed on the surface of the porous structure of Example 2. It can be seen that the porous structure ceramic fire-retardant material of the present application has a more uniform porous structure, high compressive strength and good mechanical properties.

[0050] 4. Spectral detection of free radicals in hydrogen-containing combustible gas flames The porous ceramic fire-retardant materials of Examples 1-2 and the control group were prepared into thin plates with a thickness of 0.5 mm for later use.

[0051] The experimental equipment includes: diffusion flame burner, hydrogen-containing combustible gas, and spectrum data acquisition device.

[0052] The hydrogen-containing combustible gas is composed of hydrogen and methane in a volume ratio of 1:3.

[0053] The spectral data acquisition device has a spectral range of 200-1000 nm, a resolution of 2 nm, and a scanning frequency of 200 Hz.

[0054] Adjust the nozzle of the diffusion flame burner to face the thin plate at a distance of 20 cm. The axis of the optical fiber probe of the spectral data acquisition device faces the contact point between the flame and the thin plate. Set the nozzle gas flow of the diffusion flame burner to 0.05L / s and the nozzle diameter to 70mm. Collect data on the flame spectrum characteristics. Each group of tests is repeated 5 times to obtain the spectral line intensity of the characteristic spectrum at 784.9nm in the OH near-infrared band. The results are as follows: Figure 5 It can be seen that the porous ceramic fire-retardant material of the present application can eliminate the free radicals generated by hydrogen-containing combustible gas to a certain extent, and has better fire-retardant, heat-insulating and fire-extinguishing properties.

[0055] Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a hydrogen-eliminating porous ceramic fire-retardant material, characterized in that: The steps include: 1) A quaternary ammonium solution, cellulose, and a solvent are mixed evenly, and then modified polysaccharides and amino acid derivatives are added and continued to mix. Then, an inert gas is introduced to foam the mixture, and the mixture is transferred to a coagulation liquid for setting. After washing, a cellulose-based foam material is obtained. 2) Deionized water, N-alkyl acrylamide, and fatty acid iron salt are uniformly mixed to prepare a pre-fluid, and aluminum sulfate, urea, and unsaturated dicarboxylic acid are slowly added to the pre-fluid to prepare a modifying solution. The cellulose-based foam material is then immersed in the modifying solution, subjected to microwave heating, and then removed, washed, and dried to obtain a template material. 3) Ceramic powder, water, ethanol, binder, rheological agent, dispersant and plasticizer are mixed evenly to prepare ceramic slurry. Then the template material is immersed in the prepared ceramic slurry. After the ceramic slurry evenly wraps the template material, the excess slurry is squeezed out and finally dried and sintered to obtain the product.

2. The method for preparing the hydrogen-eliminating porous structure ceramic fire-retardant material according to claim 1, characterized in that: In the step 1), the mass volume ratio of the quaternary ammonium solution, cellulose, and solvent is (65-70) mL: (10-15) g: (20-30) mL; And / or, in step 1), the solvent is one of DMF, DMSO, and DMAC; And / or, in step 1), the amino acid derivative is one or more of phthaloylglycine, palmitoylglycine, and N-benzoylglycine.

3. The method for preparing the hydrogen-scavenging porous structure ceramic fire-retardant material according to claim 1, characterized in that: The preparation method of the modified polysaccharide comprises the following steps: a) taking a flaxseed gum solution, adding polysaccharide and casein, stirring until fully dissolved, and adjusting the pH to a weakly alkaline pH to obtain a mixed solution; b) adding sodium tetraborate and β-mercaptoethanol to the mixed solution, reacting at 85-95° C. for 60-80 minutes to obtain a modified polysaccharide.

4. The method for preparing the hydrogen-scavenging porous ceramic fire-retardant material according to claim 3, characterized in that: The polysaccharide is one or more of konjac gum, pectin and xanthan gum.

5. The method for preparing the hydrogen-scavenging porous ceramic fire-retardant material according to claim 1, characterized in that: In the step 2), the mass ratio of deionized water, N-alkyl acrylamide, and fatty acid salt is 1:(0.1-0.15):(0.05-0.1); And / or, in step 2), the fatty acid iron salt is one or more of iron stearate, iron palmitate, iron stearate, and iron oleate; And / or, in step 2), the N-alkyl acrylamide is one or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, and N-octadecyl acrylamide; And / or, the unsaturated dicarboxylic acid is one of fumaric acid, maleic acid, and glutaconic acid.

6. The method for preparing the hydrogen-scavenging porous structure ceramic fire-retardant material according to claim 1, characterized in that: In step 3), the ceramic powder includes aluminum oxide, zirconium oxide, and magnesium oxide; And / or, in step 3), the binder is one of polyvinyl alcohol, sodium carboxymethyl cellulose, polyethyleneimine, silica sol, aluminum phosphate, borate, sodium silicate, and potassium silicate; And / or, in step 3), the rheological agent is one of carboxymethyl cellulose, hydroxyethyl cellulose, bentonite, and kaolin; And / or, in step 3), the dispersant is one of citric acid, sodium polymetaphosphate, polyacrylamide, polyvinyl alcohol, and polyvinyl ether; And / or, in step 3), the plasticizer is one of talc powder, mica powder, and dioctyl phthalate.

7. The method for preparing the hydrogen-scavenging porous structure ceramic fire-retardant material according to claim 1, characterized in that: The coagulation liquid comprises the following raw materials in weight fractions: 100-150 parts of water, 5-10 parts of sulfuric acid, 0.15-0.2 parts of carrageenan, 0.8-1.2 parts of cyclodextrin derivative, 1-3 parts of nickel nitrate, and 2-5 parts of manganese nitrate.

8. The method for preparing the hydrogen-scavenging porous ceramic fire-retardant material according to claim 7, characterized in that: The cyclodextrin derivative is prepared by a method comprising the following steps: Ⅰ) Add imidazole-1-acetic acid to dichloromethane and stir until completely dissolved, then add oxalyl chloride, heat under reflux for reaction, and remove the solvent to obtain imidazole-1-acetyl chloride; II) Dissolve cyclodextrin in DMF, add triethylamine and mix well, then slowly add DMF solution containing imidazole-1-acetyl chloride into the system, wash with acetone after sufficient reaction, then redissolve with deionized water and dry to obtain the product.

9. A hydrogen-eliminating porous ceramic fire-retardant material, characterized by: The method is as described in any one of claims 1 to 8.

10. An application of a hydrogen-eliminating porous ceramic fire-retardant material, characterized in that: The hydrogen-eliminating porous structure ceramic fire-retardant material prepared by the preparation method according to any one of claims 1 to 8 is used for building fireproof panels, industrial kiln insulation layers, and aviation insulation parts.

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