CN-122010122-A - High-flame-retardance ultraviolet-resistant aerogel powder catalyzed by phosphorus acid source and preparation method thereof

CN122010122ACN 122010122 ACN122010122 ACN 122010122ACN-122010122-A

Abstract

The invention discloses a phosphorus acid source catalytic high-flame-retardance ultraviolet-resistant aerogel powder and a preparation method thereof. The preparation method comprises the steps of S1, adding TiO 2 powder into ethanol, adding nitric acid to adjust the pH value, adding aminoalkyltriethoxysilane to stir, washing after heating reaction, vacuum drying to obtain modified TiO 2 , S2, dropwise adding phosphoric acid source while stirring, carrying out water bath hydrolysis after dropwise adding, S3, adding modified TiO 2 into the solution obtained in S2, dropwise adding ammonia water to induce a system to carry out gelation reaction after stirring, S4, adding absolute ethyl alcohol and n-hexane to carry out solvent exchange after gelling, S5, adding a mixed solution of a hydrophobic modifier and n-hexane to carry out surface modification to obtain a wet gel composite material, and S6, drying to obtain the flame-retardant hydrophobic silica/modified @ TiO 2 aerogel composite material. The HSA composite material of the invention has remarkable improvement on fireproof and ultraviolet resistance.

Inventors

XU BIAO
YANG KUN
Tian Gangsheng
LIU MIAO
LI ZHI
ZHANG SHAOQIAN

Assignees

中国交通建设股份有限公司总承包经营分公司
中南大学

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (9)

1. The preparation method of the phosphorus acid source catalytic high-flame-retardance ultraviolet-resistant aerogel powder is characterized by comprising the following steps of: S1, adding TiO 2 powder into ethanol, performing ultrasonic treatment on the solution by using ultrasonic treatment equipment to form a uniform solution, then adding nitric acid to adjust the pH of the solution to 2-3, then adding aminoalkyltriethoxysilane, stirring, heating to 70 ℃ for continuous reaction, washing a sample after the reaction is completed, and performing vacuum drying on the sample to obtain modified TiO 2 ; S2, mixing tetraethyl orthosilicate, absolute ethyl alcohol and deionized water, then placing the mixture into a stirring container, dropwise adding a phosphorus acid source while stirring to adjust the pH of the mixed solution to 2-3, and placing the obtained solution into a water bath for hydrolysis after the dropwise adding is completed; s3, adding the modified TiO 2 synthesized in the step S1 into the solution obtained in the step S2, stirring at normal temperature and normal pressure, and uniformly mixing by using an ultrasonic disperser; S4, adding absolute ethyl alcohol after the gel for solvent exchange, and then using n-hexane for solvent exchange; S5, adding a mixed solution of a hydrophobic modifier and n-hexane into the gel obtained in the step S4, completely immersing the gel, and carrying out surface modification to obtain a flame-retardant hydrophobic silica/modified @ TiO 2 wet gel composite material; S6, drying the obtained flame-retardant hydrophobic silica/modified @ TiO 2 wet gel composite material to obtain the flame-retardant hydrophobic silica/modified @ TiO 2 aerogel composite material.
2. The preparation method of the phosphorus acid source catalyzed high-flame-retardance ultraviolet-resistant aerogel powder disclosed by claim 1 is characterized in that in the step S5, the hydrophobic modifier comprises hexamethyldisiloxane, hexamethyldisilazane and hexamethyldisilane, and the hydrophobic modifier accounts for 1% -20% of the volume fraction of the mixed solution.
3. The preparation method of the phosphorus acid source catalyzed high-flame-retardance ultraviolet-resistant aerogel powder is characterized by comprising the steps of adding aminoalkyltriethoxysilane, stirring for 30-60 minutes, heating to 70-80 ℃ for continuous reaction for 8-12 hours, repeatedly washing a sample to be neutral by using ethanol and deionized water after the reaction is completed, and finally, carrying out vacuum drying on the sample at 80-100 ℃.
4. The method for preparing the phosphorus acid source catalyzed high flame retardant ultraviolet resistant aerogel powder according to claim 1, wherein in the step S2, tetraethyl orthosilicate, absolute ethyl alcohol and deionized water are mixed according to a volume ratio of 5-6:15:1-1.5, then the mixture is placed into a stirring container, the phosphorus acid source is dropwise added while stirring, stirring is continued for 5-10 minutes after the dropwise adding is completed, and then the obtained solution is placed into a water bath kettle at 45-55 ℃ for hydrolysis for 12-16 hours.
5. The method for preparing the phosphorus acid source catalyzed high flame retardant ultraviolet resistant aerogel powder according to claim 1, wherein in the step S3, the mixture is stirred for 3-5 minutes at the normal temperature and the normal pressure at 300-500 r/min, and then the mixture is uniformly mixed by using an ultrasonic disperser.
6. The method for preparing the phosphorus acid source catalyzed high flame retardant ultraviolet resistant aerogel powder according to claim 1, wherein in the step S4, the solvent is exchanged 2-3 times by adding absolute ethyl alcohol after 3-4 hours of gel, and then the solvent is exchanged 2-3 times by using normal hexane.
7. The method for preparing the phosphorus acid source catalyzed high flame retardant ultraviolet resistant aerogel powder according to claim 1, wherein in the step S5, a mixed solution of a hydrophobic modifier and n-hexane is added into the gel obtained in the step S4, and the mixture is placed in an environment of 30-60 ℃ for surface modification for 24-48 hours.
8. The method for preparing the phosphorus acid source catalyzed high flame retardant ultraviolet resistant aerogel powder according to claim 1, wherein in the step S6, the obtained flame retardant hydrophobic silica/modified @ TiO 2 wet gel composite material is dried for 1-4 hours at 100-150 ℃ to obtain the flame retardant hydrophobic silica/modified @ TiO 2 aerogel composite material.
9. The phosphorus acid source catalytic high-flame-retardance ultraviolet-resistant aerogel powder is characterized in that the phosphorus acid source catalytic high-flame-retardance ultraviolet-resistant aerogel powder is prepared by adopting the preparation method of the phosphorus acid source catalytic high-flame-retardance ultraviolet-resistant aerogel powder according to any one of claims 1-8.

Description

High-flame-retardance ultraviolet-resistant aerogel powder catalyzed by phosphorus acid source and preparation method thereof Technical Field The invention belongs to the technical field of aerogel materials, and particularly relates to phosphorus acid source catalysis high-flame-retardance ultraviolet-resistant aerogel powder and a preparation method thereof. Background In high-cold high-altitude areas, extreme climatic conditions and intense ultraviolet radiation place higher demands on the performance of the insulation material. In such environments, the insulation material is required to have not only excellent heat insulating properties, but also to be able to effectively resist ultraviolet radiation. Traditional thermal insulation materials are mainly classified into organic and inorganic materials. Although the organic heat-insulating material (such as EPS heat-insulating board) has the advantages of light weight, convenient construction and the like, the inflammable and ageing disadvantages limit the application range, and the inorganic heat-insulating material (such as rock wool) has good fireproof performance, but has water absorption problem in practical application and influences the use effect. Therefore, there is an urgent need to develop a thermal insulation material having excellent thermal insulation properties, flame retardancy, water resistance and ultraviolet resistance. Hydrophobic Silica Aerogel (HSA) has become an ideal high-efficiency heat-insulating material due to its low density, excellent heat-insulating property and high porosity, and is especially suitable for high-cold high-altitude areas. However, although HSA has some uv resistance and can effectively block uv penetration, long-term exposure to intense uv radiation in environments with high uv radiation intensity can lead to gradual degradation of its performance. In addition, the hydrophobicity of HSA is obtained by hydrophobically modifying silica aerogel. However, hydrophobic modification generally requires the introduction of organic groups which, while enhancing hydrophobicity, may also increase the flammability of the aerogel, with a risk of fire. Therefore, how to effectively improve the ultraviolet resistance and flame retardant property of HSA has become a technical problem to be solved. Currently, there is limited research to improve the ultraviolet resistance of HSA. The existing ultraviolet resistance technology mainly realizes ultraviolet absorption by doping titanium dioxide (TiO 2). For example, zhai et al enhance the ultraviolet resistance of aramid fibers by doping with TiO 2. However, the TiO 2 doping process often suffers from uneven dispersion of the material and has a negative impact on other properties such as thermal insulation and hydrophobicity. Therefore, it is important to carry out the modification treatment in order to enhance the compatibility of TiO 2 with the matrix. Li et al improve the compatibility with the polylactic acid matrix by modifying TiO 2, thereby effectively improving the performance of the composite material. Therefore, by modifying the TiO 2, the compatibility with the HSA matrix is further improved, and the uv protective performance of HSA can be significantly enhanced while maintaining or improving the heat insulation and hydrophobicity thereof. There has been some research progress in improving the flame retardant properties of HSA. Dopants such as sepiolite, halloysite nanotubes, aluminum hydroxide, magnesium hydroxide, etc. have been added to the HSA matrix to enhance its flame retardancy. However, these dopants, while improving flame retardant properties, typically sacrifice HSA's key properties such as thermal insulation and hydrophobicity. Therefore, there is a need to develop new strategies to improve the flame retardant properties of HSA without compromising other important properties. Conventional HSA production often relies on strong acid catalysts (e.g., nitric acid, hydrochloric acid, etc.), which are not only significantly corrosive, may damage equipment in industrial production, but also produce large amounts of acidic wastewater, resulting in serious environmental problems (e.g., water acidification and soil contamination). In addition, the use of strong acids presents additional safety hazards and may endanger the health of the operator. However, the current methods of adding dopants to HSA substrates still have limitations that make it difficult to compromise uv protection, flame retardant properties, and other key properties. Therefore, a new phosphorus acid source catalytic high-flame-retardance ultraviolet-resistant aerogel powder and a preparation method thereof are needed to be designed. Disclosure of Invention The invention aims to provide phosphorus acid source catalysis high-flame-retardance ultraviolet-resistant aerogel powder and a preparation method thereof, and aims to solve the problems that the existing method for adding dopants into an HSA matr