Fireproof heat-resistant aerogel material and preparation method thereof
By filling the aerogel inside and outside the fiber porous framework, and adding polymethyl methacrylate microspheres and potassium hexatitinolate whiskers, the problem of insufficient mechanical properties of existing aerogel materials is solved, and higher strength and heat resistance are achieved, expanding its application range.
Patent Information
- Application Number
- CN202510266488.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-06-06
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The mechanical properties of existing aerogel materials are weak, which limits their application range in high-temperature equipment, fire protection and heat insulation.
A fiber porous skeleton is used as a supporting structure, and a sufficient amount of aerogel is filled inside and outside the fiber skeleton to form a composite structure aerogel material. The strength and heat resistance of the material are improved by the addition of polymethyl methacrylate microspheres and potassium hexattitanate whiskers.
It significantly improves the overall strength and heat resistance of aerogel materials, and expands its application range in high-temperature equipment, fire protection and heat insulation.
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Figure CN120097702A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of aerogel materials, in particular to a fireproof and heat-resistant aerogel material and a preparation method thereof. Background Art
[0002] Aerogel is a nanoporous material with a three-dimensional network structure, which has the characteristics of low density, high porosity, high specific surface area and low thermal conductivity. Among them, silica aerogel is the one with the most application potential, and is widely used in high-temperature equipment, fire protection and thermal insulation. However, the special structure of aerogel also leads to its weak mechanical properties, which limits its scope of application. Many scholars have conducted extensive research over the years and adopted methods such as polymer cross-linking and fiber embedding to improve this problem. Usually, the polymer or fiber is directly added to the gel precursor solution, and the quality improvement of the obtained aerogel material is limited. Based on this, a fire-resistant and heat-resistant aerogel material and a preparation method thereof are proposed. Summary of the invention
[0003] In view of the deficiencies in the prior art, the present invention provides a fire-resistant and heat-resistant aerogel material and a preparation method thereof, which uses a fiber porous skeleton as a supporting structure and fills a sufficient amount of aerogel inside and outside the fiber skeleton to form an aerogel material with a composite structure, thereby improving the strength and heat resistance.
[0004] To achieve the above object, the present invention provides the following technical solution: a method for preparing a fireproof and heat-resistant aerogel material, comprising the following steps:
[0005] (1) uniformly stirring a silica sol binder, polymethyl methacrylate microspheres, a fiber material, and deionized water to obtain a mixed slurry;
[0006] (2) injecting the mixed slurry into a mold, performing freeze drying after gelation in a water bath, and then performing high temperature heat treatment to obtain a fibrous porous skeleton;
[0007] (3) adding potassium hexatitanate whiskers to the gel precursor solution and stirring the solution to obtain a modified gel precursor solution;
[0008] (4) The fiber porous skeleton is immersed in a modified gel precursor solution, the gel is allowed to stand and is aged at room temperature, and then immersed in a mixture of trimethylchlorosilane and ethanol, and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
[0009] Preferably, in step (1), the fiber material is selected from basalt fiber and glass fiber.
[0010] Preferably, in step (1), the proportions of the components in the mixed slurry are as follows, by mass percentage: 70-80% silica sol, 1-2% polymethyl methacrylate microspheres, 10-15% fiber material, and the remainder is ionized water.
[0011] Preferably, in step (2), the heat treatment temperature is 350-400°C.
[0012] Preferably, in step (3), the potassium hexatitanate whiskers account for 3-10% of the mass of the gel precursor solution.
[0013] Preferably, in step (3), the preparation method of the gel precursor solution is as follows: S1, uniformly mix tetraethyl orthosilicate and anhydrous ethanol, adjust the pH to 3-4 with hydrochloric acid solution, then add deionized water, and stir at 60-70°C for 2.5-3.5h to obtain a sol solution; S2, add ammonia water to the sol solution, adjust the pH to 8-9, and obtain a gel precursor solution.
[0014] Preferably, in steps S1-S2, the molar ratio of tetraethyl orthosilicate, anhydrous ethanol and deionized water is 1:(5-8):(2-3); the concentration of the hydrochloric acid solution is 0.2 mol / L, and the concentration of the ammonia water is 0.4 mol / L.
[0015] Preferably, in step (4), the volume ratio of trimethylsilyl chloride to ethanol is 1:10.
[0016] Preferably, in step (4), the aging treatment time is 36-48 hours.
[0017] The present invention also provides a fireproof and heat-resistant aerogel material prepared by the method for preparing the fireproof and heat-resistant aerogel material.
[0018] The present invention provides a fireproof and heat-resistant aerogel material and a preparation method thereof, which has the following beneficial effects compared with the prior art:
[0019] The present invention uses a fiber porous skeleton as a supporting structure, and fills a sufficient amount of aerogel inside and outside the fiber skeleton by impregnating a modified gel precursor solution to form an aerogel material with a composite structure, thereby enhancing the overall strength and ensuring that the aerogel material with the composite structure has good thermal insulation and heat resistance properties.
[0020] The present invention adds polymethyl methacrylate microspheres to the fiber porous skeleton, and then thermally decomposes them at high temperature, thereby generating a large number of pores in the fiber skeleton, improving its heat insulation and heat resistance performance, and having little effect on the strength of the fiber porous skeleton.
[0021] The invention helps to improve the strength of the aerogel itself by adding a small amount of potassium hexatitanate whiskers into the gel precursor solution, and greatly improves the strength and heat resistance of the aerogel material under the joint action of the fiber porous skeleton. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0023] Figure 1 This is a microstructure diagram of the fiber porous skeleton in Example 4 of the present invention. DETAILED DESCRIPTION
[0024] The following examples are used to explain the implementation methods of the present application in detail, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.
[0025] Example 1
[0026] The preparation method of the gel precursor solution is as follows:
[0027] S1. Evenly mix tetraethyl orthosilicate and anhydrous ethanol, adjust the pH to 3 with 0.2 mol / L hydrochloric acid solution, then add deionized water, and stir at 65° C. for 3 h to obtain a sol solution;
[0028] The molar ratio of the above-mentioned ethyl orthosilicate, anhydrous ethanol and deionized water is 1:5:2.
[0029] S2. Add 0.4 mol / L ammonia water to the sol solution and adjust the pH to -9 to obtain a gel precursor solution.
[0030] Example 2
[0031] The preparation method of the gel precursor solution is as follows:
[0032] S1. Evenly mix ethyl orthosilicate and anhydrous ethanol, adjust the pH to 4 with 0.2 mol / L hydrochloric acid solution, then add deionized water, and stir at 60° C. for 3.5 h to obtain a sol solution;
[0033] The molar ratio of the above-mentioned ethyl orthosilicate, anhydrous ethanol and deionized water is 1:8:3.
[0034] S2. Add 0.4 mol / L ammonia water to the sol solution and adjust the pH to 8 to obtain a gel precursor solution.
[0035] Example 3
[0036] The preparation method of the gel precursor solution is as follows:
[0037] S1. Evenly mix tetraethyl orthosilicate and anhydrous ethanol, adjust the pH to 3 with 0.2 mol / L hydrochloric acid solution, then add deionized water, and stir at 70° C. for 2.5 h to obtain a sol solution;
[0038] The molar ratio of the above-mentioned ethyl orthosilicate, anhydrous ethanol and deionized water is 1:6:2.
[0039] S2. Add 0.4 mol / L ammonia water to the sol solution and adjust the pH to 8 to obtain a gel precursor solution.
[0040] Example 4
[0041] A method for preparing a fireproof and heat-resistant aerogel material comprises the following steps:
[0042] (1) uniformly stirring a silica sol binder, polymethyl methacrylate microspheres, basalt fibers and deionized water to obtain a mixed slurry;
[0043] In terms of mass percentage, the proportions of the components in the mixed slurry are as follows: 75% silica sol, 1.8% polymethyl methacrylate microspheres, 12% basalt fiber, and the balance is ionized water.
[0044] (2) The mixed slurry is injected into a mold, and after being gelled in a water bath, it is freeze-dried, and then heat-treated at 380°C to obtain a fibrous porous skeleton.
[0045] (3) Adding potassium hexatitanate whiskers to the gel precursor solution, wherein the potassium hexatitanate whiskers account for 6% of the mass of the gel precursor solution, and stirring the solution to obtain a modified gel precursor solution.
[0046] (4) The fiber porous skeleton is immersed in the modified gel precursor solution, the gel is allowed to stand and aged at room temperature for 40 hours, and then immersed in a mixture of trimethylchlorosilane and ethanol (1:10 v / v), and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
[0047] In this embodiment, the gel precursor solution prepared in Example 1 is used.
[0048] Example 5
[0049] A method for preparing a fireproof and heat-resistant aerogel material comprises the following steps:
[0050] (1) uniformly stirring a silica sol binder, polymethyl methacrylate microspheres, glass fibers and deionized water to obtain a mixed slurry;
[0051] In terms of mass percentage, the proportions of the components in the mixed slurry are as follows: 80% silica sol, 1% polymethyl methacrylate microspheres, 10% glass fiber, and the balance is ionized water.
[0052] (2) The mixed slurry is injected into a mold, and after being gelled in a water bath, it is freeze-dried and subsequently heat-treated at 350°C to obtain a fibrous porous skeleton.
[0053] (3) Adding potassium hexatitanate whiskers to the gel precursor solution, wherein the potassium hexatitanate whiskers account for 10% of the mass of the gel precursor solution, and stirring the solution to obtain a modified gel precursor solution.
[0054] (4) The fiber porous skeleton is immersed in the modified gel precursor solution, the gel is allowed to stand and aged at room temperature for 36 hours, and then immersed in a mixture of trimethylchlorosilane and ethanol (1:10 v / v), and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
[0055] In this embodiment, the gel precursor solution prepared in Example 2 is used.
[0056] Example 6
[0057] A method for preparing a fireproof and heat-resistant aerogel material comprises the following steps:
[0058] (1) uniformly stirring a silica sol binder, polymethyl methacrylate microspheres, basalt fibers and deionized water to obtain a mixed slurry;
[0059] In terms of mass percentage, the proportions of the components in the mixed slurry are as follows: 70% silica sol, 2% polymethyl methacrylate microspheres, 15% basalt fiber, and the balance is ionized water.
[0060] (2) The mixed slurry is injected into a mold, and after being gelled in a water bath, it is freeze-dried, and then heat-treated at 400°C to obtain a fibrous porous skeleton.
[0061] (3) Adding potassium hexatitanate whiskers to the gel precursor solution, wherein the potassium hexatitanate whiskers account for 3% of the mass of the gel precursor solution, and stirring the solution to obtain a modified gel precursor solution.
[0062] (4) The fiber porous skeleton is immersed in the modified gel precursor solution, the gel is allowed to stand and aged at room temperature for 48 hours, and then immersed in a mixture of trimethylchlorosilane and ethanol (1:10 v / v), and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
[0063] In this embodiment, the gel precursor solution prepared in Example 3 is used.
[0064] Comparative Example 1
[0065] A method for preparing a fireproof and heat-resistant aerogel material comprises the following steps:
[0066] (1) uniformly stirring a silica sol binder, basalt fiber and deionized water to obtain a mixed slurry;
[0067] In terms of mass percentage, the proportions of the components in the mixed slurry are as follows: 75% silica sol, 12% basalt fiber, and the balance is ionized water.
[0068] (2) The mixed slurry is injected into a mold, and after being gelled in a water bath, it is freeze-dried, and then heat-treated at 380°C to obtain a fibrous porous skeleton.
[0069] (3) Adding potassium hexatitanate whiskers to the gel precursor solution, wherein the potassium hexatitanate whiskers account for 6% of the mass of the gel precursor solution, and stirring the solution to obtain a modified gel precursor solution.
[0070] (4) The fiber porous skeleton is immersed in the modified gel precursor solution, the gel is allowed to stand and aged at room temperature for 40 hours, and then immersed in a mixture of trimethylchlorosilane and ethanol (1:10 v / v), and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
[0071] In this comparative example, the gel precursor solution prepared in Example 1 was used.
[0072] Comparative Example 2
[0073] A method for preparing a fireproof and heat-resistant aerogel material comprises the following steps:
[0074] (1) uniformly stirring a silica sol binder, polymethyl methacrylate microspheres, basalt fibers and deionized water to obtain a mixed slurry;
[0075] In terms of mass percentage, the proportions of the components in the mixed slurry are as follows: 75% silica sol, 1.8% polymethyl methacrylate microspheres, 12% basalt fiber, and the balance is ionized water.
[0076] (2) injecting the mixed slurry into a mold, performing freeze drying after water bath gelation, and then performing high temperature heat treatment at 380° C. to obtain a fibrous porous skeleton;
[0077] (3) The fiber porous skeleton is immersed in a gel precursor solution, the gel is allowed to stand and aged at room temperature for 40 hours, and then immersed in a mixture of trimethylchlorosilane and ethanol (1:10 v / v), and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
[0078] In this comparative example, the gel precursor solution prepared in Example 1 was used.
[0079] Comparative Example 3
[0080] A method for preparing a fireproof and heat-resistant aerogel material comprises the following steps:
[0081] (1) uniformly stirring a silica sol binder, basalt fiber and deionized water to obtain a mixed slurry;
[0082] In terms of mass percentage, the proportions of the components in the mixed slurry are as follows: 75% silica sol, 12% basalt fiber, and the balance is ionized water.
[0083] (2) The mixed slurry is injected into a mold, and after being gelled in a water bath, it is freeze-dried, and then heat-treated at 380°C to obtain a fibrous porous skeleton.
[0084] (3) The fiber porous skeleton is immersed in a gel precursor solution, the gel is allowed to stand and aged at room temperature for 40 hours, and then immersed in a mixture of trimethylchlorosilane and ethanol (1:10 v / v), and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
[0085] In this comparative example, the gel precursor solution prepared in Example 1 was used.
[0086] Quality Inspection
[0087] The fireproof and heat-resistant aerogel materials in Examples 4-5 and Comparative Examples 1-3 were selected as test samples.
[0088] 1. Referring to the standard of GB / T 7689.5-2013, the test specimens were made into specimens with a width of 25 mm and an effective tensile length of 10 mm. The specimens were tested by a small tensile testing machine with a controlled tensile rate of 20 mm / min.
[0089] 2. The test sample was made into a 300×300 mm sample and tested using an HFM 436 thermal conductivity analyzer.
[0090] The specific test results are shown in the following table.
[0091] Table 1 Tensile strength and thermal conductivity
[0092]
[0093]
[0094] From the above table, we can see that:
[0095] (1) Compared with Example 4, the tensile strength of the sample in Comparative Example 1 is slightly improved, which is due to the small number of pores, but its thermal conductivity is significantly increased, indicating that the generation of a large number of pores in the fiber skeleton can effectively improve the heat resistance of the aerogel material and has little effect on the strength.
[0096] (2) Compared with Example 4, the tensile strength of the sample in Comparative Example 2 is significantly reduced, indicating that the addition of potassium hexatitanate whiskers can indeed improve the overall strength of the aerogel material.
[0097] (3) Compared with Example 4, the strength and heat resistance of the sample in Comparative Example 3 are significantly reduced, indicating that the combined addition of polymethyl methacrylate microspheres and potassium hexatitanate whiskers helps to improve the overall performance of the aerogel material.
[0098] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a fireproof and heat-resistant aerogel material, characterized in that: The following steps are involved: (1) uniformly stirring a silica sol binder, polymethyl methacrylate microspheres, a fiber material and deionized water to obtain a mixed slurry; (2) injecting the mixed slurry into a mold, performing freeze drying after water bath gelation, and then performing high temperature heat treatment to obtain a fibrous porous skeleton; (3) adding potassium hexatitanate whiskers to the gel precursor solution and stirring the solution to obtain a modified gel precursor solution; (4) The fiber porous skeleton is immersed in a modified gel precursor solution, the gel is allowed to stand and is aged at room temperature, and then immersed in a mixture of trimethylchlorosilane and ethanol, and then washed and dried with ethanol to obtain a fire-resistant and heat-resistant aerogel material.
2. The method for preparing a fireproof and heat-resistant aerogel material according to claim 1, characterized in that: In step (1), the fiber material is selected from basalt fiber and glass fiber.
3. The method for preparing a fireproof and heat-resistant aerogel material according to claim 1, characterized in that: In step (1), the proportions of the components in the mixed slurry are as follows, by mass percentage: 70-80% silica sol, 1-2% polymethyl methacrylate microspheres, 10-15% fiber material, and the remainder is ionized water.
4. The method for preparing a fireproof and heat-resistant aerogel material according to claim 1, characterized in that: In step (2), the heat treatment temperature is 350-400°C.
5. The method for preparing a fireproof and heat-resistant aerogel material according to claim 1, characterized in that: In step (3), the potassium hexatitanate whiskers account for 3-10% of the mass of the gel precursor solution.
6. The method for preparing a fireproof and heat-resistant aerogel material according to claim 1, characterized in that: In step (3), the preparation method of the gel precursor solution is as follows: S1. Evenly mix tetraethyl orthosilicate and anhydrous ethanol, adjust the pH to 3-4 with hydrochloric acid solution, then add deionized water, and stir at 60-70° C. for 2.5-3.5 hours to obtain a sol solution; S2. Add ammonia water to the sol solution and adjust the pH to 8-9 to obtain a gel precursor solution.
7. The method for preparing a fireproof and heat-resistant aerogel material according to claim 6, characterized in that: In step S1-S2, the molar ratio of tetraethyl orthosilicate, anhydrous ethanol and deionized water is 1:(5-8):(2-3); the concentration of hydrochloric acid solution is 0.2 mol / L, and the concentration of ammonia water is 0.4 mol / L.
8. The method for preparing a fireproof and heat-resistant aerogel material according to claim 1, characterized in that: In step (4), the volume ratio of trimethylsilyl chloride to ethanol is 1:
10.
9. The method for preparing a fireproof and heat-resistant aerogel material according to claim 1, characterized in that: In step (4), the aging treatment time is 36-48 hours.
10. A fireproof and heat-resistant aerogel material prepared by the preparation method according to any one of claims 1 to 9.