Preparation method and application of organic silicon modified waterborne polyurethane aerogel

Abstract

The invention discloses a preparation method and application of organic silicon modified waterborne polyurethane aerogel. The preparation method comprises the following steps: preparing raw materials: selecting a waterborne polyurethane emulsion, an organic silicon compound, a catalyst dibutyltin dilaurate and a cross-linking agent aziridine; pretreatment: carrying out ultrasonic dispersion treatment on the waterborne polyurethane emulsion; organic silicon modification: adding an organic silicon compound into the pretreated waterborne polyurethane emulsion; introducing a nano reinforcing agent: adding nano silicon dioxide after the organic silicon is modified; gelation treatment: performing gelation treatment on the system into which the nano reinforcing agent is introduced, and controlling the gelation speed and degree to form a stable gel structure; a supercritical drying method is adopted, and a drying medium is carbon dioxide. By accurately controlling raw materials and process parameters, the performance of the aerogel can be enhanced, and the aerogel can be applied to the fields of heat insulation, sound absorption and adsorption, has the advantages of low heat conductivity coefficient, high porosity, large specific surface area and the like, and provides an efficient solution for related fields.

Description

Technical Field

[0001] The invention relates to the technical field of aerogels, and in particular to a preparation method and application of organosilicon-modified waterborne polyurethane aerogels. Background Art

[0002] In today's material science field, the continuous search for high-performance, multifunctional new materials has become a hot topic and key direction of research. As a new material with great potential, the research and development background of silicone-modified waterborne polyurethane aerogel is driven by profound practical needs and technological development.

[0003] With the intensification of the global energy crisis and the continuous improvement of environmental protection awareness, the demand for efficient thermal insulation materials is becoming increasingly urgent. Traditional thermal insulation materials, such as polystyrene foam, rock wool, etc., although they can play a role in heat insulation to a certain extent, often have problems such as high thermal conductivity, easy aging, and flammability. These shortcomings not only limit their application in some fields with high requirements for safety and durability, but also do not conform to the modern society's pursuit of green environmental protection and sustainable development. In addition, in terms of sound-absorbing materials, existing materials such as fiber sound-absorbing panels, foam plastics, etc., usually have limited sound absorption effects, poor durability, and are susceptible to moisture. In the field of adsorption materials, traditional adsorption materials such as activated carbon, etc., although they have certain adsorption capacity, have relatively small specific surface area, limited adsorption performance, and are difficult to adapt to complex environmental conditions.

[0004] As a material with good flexibility, wear resistance and chemical corrosion resistance, waterborne polyurethane has been widely used in many fields. However, some of its special properties still need to be improved. Silicone materials have attracted much attention for their excellent heat resistance, weather resistance, low surface energy and other properties. Combining silicone with waterborne polyurethane is expected to give full play to the advantages of both and prepare materials with better performance.

[0005] In the existing technology, although there have been some studies on silicone-modified waterborne polyurethane materials, there are still many shortcomings. On the one hand, the existing preparation methods are often complicated, requiring multi-step reactions and complex equipment, resulting in high production costs and difficulty in large-scale industrial production. On the other hand, the performance stability of existing materials is insufficient, and performance is prone to degradation under different environmental conditions. For example, in harsh environments such as high temperature and high humidity, the thermal insulation, sound absorption and adsorption properties of the material may be greatly affected.

[0006] In addition, there are relatively few studies on the application of silicone-modified waterborne polyurethane materials in specific fields such as heat insulation, sound absorption and adsorption. The lack of targeted optimization and innovation makes it difficult for the materials to fully exert their advantages in practical applications. At the same time, the existing materials may also have compatibility issues with other materials during the application process, which requires further improvement and optimization.

[0007] In summary, developing a new method for preparing silicone-modified waterborne polyurethane aerogel and conducting in-depth research on its application in the fields of thermal insulation, sound absorption and adsorption materials has important practical significance and broad market prospects. This can not only meet the demand for high-performance materials in modern society and promote the development of related industries, but also provide new ideas and methods for solving global problems such as energy crisis and environmental protection. Summary of the invention

[0008] The present invention provides a preparation method and application of an organosilicon-modified waterborne polyurethane aerogel to solve the problems mentioned in the above-mentioned prior art.

[0009] In order to achieve the above object, the present invention adopts the following technical scheme: a method for preparing silicone-modified waterborne polyurethane aerogel, comprising the following steps:

[0010] Raw material preparation: select water-based polyurethane emulsion with a solid content of 30%-40%, select vinyl-containing silicone monomers or silicone polymers with a molecular weight of 1000-3000 as the organosilicon compound, and prepare the catalyst dibutyltin dilaurate, accounting for 0.1%-0.3% of the total mass of the raw materials, and the cross-linking agent aziridine, accounting for 0.5%-1% of the total mass of the raw materials;

[0011] Pretreatment: ultrasonic dispersion treatment of waterborne polyurethane emulsion, ultrasonic power is 200-300W, time is 20-30 minutes;

[0012] Silicone modification: Add the silicone compound to the pre-treated aqueous polyurethane emulsion, react at a temperature of 60-80°C and a stirring speed of 150-200 rpm for 3-5 hours;

[0013] Introducing nano-enhancers: Adding nano-silicon dioxide after silicone modification, the particle size of nano-silicon dioxide is 20-50 nanometers, accounting for 1%-3% of the total mass of the raw materials;

[0014] Gel treatment: The system after the introduction of the nano-enhancer is subjected to gel treatment by lowering the temperature to 20-30°C, adjusting the pH value to 6-7, adding gelling agent calcium chloride, accounting for 1%-2% of the total mass of the raw materials, controlling the speed and degree of gelation, and forming a stable gel structure;

[0015] Drying and molding: The supercritical drying method is adopted, the drying medium is carbon dioxide, the drying temperature is 40-50°C, and the pressure is 8-12MPa. The gel is dried to remove the solvent therein to form a silicone-modified waterborne polyurethane aerogel.

[0016] Furthermore, the solid content of the aqueous polyurethane emulsion is within a range of 30%-40%.

[0017] Furthermore, the organosilicon compound is an organosilicon monomer or an organosilicon polymer containing vinyl groups. When it is an organosilicon monomer, the number of vinyl groups in its molecular structure is not less than two, and when it is an organosilicon polymer, its molecular weight ranges from 1500 to 2500.

[0018] Furthermore, the catalyst is dibutyltin dilaurate, accounting for 0.15%-0.25% of the total mass of the raw materials, and the cross-linking agent is aziridine, accounting for 0.6%-0.8% of the total mass of the raw materials.

[0019] Furthermore, during the organosilicon modification process, the reaction temperature is controlled at 65° C.-75° C., the stirring speed is set at 160 rpm-180 rpm, and the reaction time is 3.5 hours-4.5 hours.

[0020] Furthermore, in the step of introducing the nano-enhancer, the particle size of the nano-silicon dioxide is 25 nanometers to 45 nanometers, accounting for 1.5% to 2.5% of the total mass of the raw material.

[0021] Furthermore, during the gelation process, the temperature is controlled at 22° C.-28° C., the pH value is adjusted to 6.2-6.8, and the added gelling agent calcium chloride accounts for 1.2%-1.8% of the total mass of the raw materials.

[0022] Furthermore, when the supercritical drying method is adopted, the drying medium is carbon dioxide, the drying temperature is 42° C.-48° C., and the pressure is 9 MPa-11 MPa.

[0023] Furthermore, an application of an organosilicon-modified waterborne polyurethane aerogel is to apply the prepared organosilicon-modified waterborne polyurethane aerogel to the fields of thermal insulation materials, sound-absorbing materials, and adsorption materials.

[0024] Furthermore, in the application of thermal insulation materials, the aerogel has a low thermal conductivity, which is not higher than 0.025 W / (m·K);

[0025] In the application of sound-absorbing materials, the aerogel has a porous structure with a porosity between 85% and 95%;

[0026] In the application of adsorption materials, the aerogel has a high specific surface area, which is not less than 500m 2 / g.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention selects water-based polyurethane emulsion with a solid content of 30%-40% by strictly screening raw materials, thereby ensuring the stability and operability of subsequent reactions. At the same time, organic silicon monomers containing vinyl groups with specific structures or organic silicon polymers with a molecular weight of 1500-2500 are selected to give the aerogel better performance.

[0029] By pre-treating the aqueous polyurethane emulsion with ultrasonic dispersion, under the conditions of ultrasonic power of 200-300W and time of 20-30 minutes, the particles in the emulsion are more evenly dispersed, thereby improving the efficiency and uniformity of subsequent reactions.

[0030] During the silicone modification process, the reaction temperature is controlled at 65°C-75°C, the stirring speed is 160-180 rpm, and the reaction time is 3.5-4.5 hours to ensure that the silicone is fully grafted onto the waterborne polyurethane molecular chain to form a stable modification system.

[0031] The introduction of nano-reinforcement agent nano-silicon dioxide, with a particle size of 25-45 nanometers and accounting for 1.5%-2.5% of the total mass of the raw materials, effectively enhances the mechanical properties and stability of the aerogel.

[0032] During the gelation process, the temperature is controlled at 22°C-28°C, the pH value is adjusted to 6.2-6.8, and 1.2%-1.8% of the total mass of the raw materials is added as a gelling agent calcium chloride, so that the speed and degree of gelation are accurately controlled to obtain the best gel structure and performance.

[0033] The supercritical drying method is adopted, with carbon dioxide as the drying medium, a drying temperature of 42°C-48°C, and a pressure of 9-11MPa, to efficiently remove the solvent and form high-quality aerogel.

[0034] In terms of application, the organosilicon-modified waterborne polyurethane aerogel prepared by the present invention can be used in the fields of heat insulation, sound absorption and adsorption materials. In the application of heat insulation materials, the thermal conductivity is not higher than 0.025W / (m·K), which has good heat insulation performance; in the application of sound absorption materials, the porosity is between 85% and 95%, which can effectively absorb sound wave energy; in the application of adsorption materials, the specific surface area is not less than 500m 2 / g, and has good adsorption performance. In conclusion, the present invention provides a new approach for the preparation and application of high-performance aerogel materials. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate directions or positional relationships only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The invention provides a preparation method and application of an organosilicon-modified waterborne polyurethane aerogel, and selects an aqueous polyurethane emulsion with a solid content of 30%-40% as a basic raw material. Within this solid content range, the aqueous polyurethane emulsion can show good stability and operability in subsequent reactions, laying a solid foundation for the preparation of high-performance aerogels. At the same time, a vinyl-containing organosilicon monomer or an organosilicon polymer with a molecular weight of 1000-3000 is selected as a key modified component. When an organosilicon monomer is selected, the number of vinyl groups in its molecular structure is not less than two, ensuring that it has sufficient reactivity and can be fully combined with waterborne polyurethane. When it is an organosilicon polymer, the molecular weight is strictly controlled within a specific range of 1500-2500 to ensure that it can give the aerogel ideal performance in the reaction. In addition, a catalyst dibutyltin dilaurate is prepared, which accounts for 0.1%-0.3% of the total mass of the raw materials, and a crosslinking agent aziridine, which accounts for 0.5%-1% of the total mass of the raw materials. These raw materials are strictly screened and tested to ensure that their purity and quality meet high standards.

[0039] Ultrasonic dispersion of waterborne polyurethane emulsion is a crucial step. The ultrasonic power is set in the range of 200-300W and the duration is 20-30 minutes. Under such ultrasonic conditions, the particles in the waterborne polyurethane emulsion can be dispersed more evenly, creating good conditions for subsequent reactions and greatly improving the efficiency and uniformity of the reaction.

[0040] Add the organosilicon compound to the pre-treated waterborne polyurethane emulsion. The reaction is carried out at a temperature of 60-80°C and a stirring speed of 150-200 rpm. This temperature range and stirring speed have been carefully optimized to ensure a smooth reaction between the organosilicon and the waterborne polyurethane. The reaction time is controlled at 3-5 hours to ensure that the organosilicon is fully grafted onto the waterborne polyurethane molecular chain to form a stable modified system.

[0041] Adding nano-silica to the organosilicon-modified system further improves the performance of aerogel. The particle size of nano-silica is 20-50 nanometers, accounting for 1%-3% of the total mass of the raw materials. Nano-silica within this particle size range can better interact with the system and enhance the mechanical properties and stability of aerogel. By precisely controlling the amount of nano-silica added, it can achieve the best enhancement effect in the system.

[0042] The system after the introduction of the nano-enhancer is gelled. First, the temperature is lowered to 20-30°C, and then the pH is adjusted to 6-7. During this process, calcium chloride, a gelling agent, is added, accounting for 1%-2% of the total mass of the raw materials. By precisely controlling these conditions, the speed and degree of gelation can be effectively controlled to form a stable gel structure. The temperature, pH value and amount of gelling agent added cooperate with each other to ensure the smooth progress of the gelation process and lay a good foundation for the subsequent drying and molding steps.

[0043] The supercritical drying method is adopted, and the drying medium is carbon dioxide. The drying temperature is controlled at 40-50℃ and the pressure is 8-12MPa. Under such specific conditions, the carbon dioxide is in a supercritical state, which can effectively remove the solvent in the gel, while avoiding problems such as gel structure collapse that may be caused by traditional drying methods. After supercritical drying treatment, silicone-modified waterborne polyurethane aerogel is finally formed.

[0044] The prepared silicone-modified waterborne polyurethane aerogel is applied to important fields such as thermal insulation materials, sound-absorbing materials, and adsorption materials.

[0045] In the application of thermal insulation materials, the aerogel has a low thermal conductivity of no more than 0.025W / (m·K). This excellent thermal insulation performance enables it to effectively reduce heat transfer and is suitable for thermal insulation in the fields of construction and industry, playing an important role in saving energy and improving environmental comfort.

[0046] In the application of sound-absorbing materials, the aerogel has a porous structure with a porosity of 85%-95%. This porous structure gives the aerogel good sound-absorbing properties, can effectively absorb sound wave energy, reduce noise pollution, and has broad application prospects in fields such as acoustic engineering.

[0047] In the application of adsorption materials, the aerogel has a high specific surface area, which is not less than 500m 2 / g. The high specific surface area makes it have good adsorption performance, and can effectively adsorb organic pollutants, heavy metal ions, etc., providing an efficient solution for environmental governance and other fields. Example 1

[0048] Raw material preparation: Select a water-based polyurethane emulsion with a solid content of 32%. Select a silicone polymer with a molecular weight of 2000. Prepare a catalyst, dibutyltin dilaurate, accounting for 0.15% of the total mass of the raw materials, and a cross-linking agent, aziridine, accounting for 0.6% of the total mass of the raw materials.

[0049] Pretreatment: The aqueous polyurethane emulsion was subjected to ultrasonic dispersion treatment, with the ultrasonic power set to 220 W and the duration being 22 minutes.

[0050] Silicone modification: Add silicone polymer to the pre-treated waterborne polyurethane emulsion. The reaction is carried out at a temperature of 65°C and a stirring speed of 170 rpm for 3.8 hours.

[0051] Introducing nano-enhancer: Adding nano-silicon dioxide into the system after silicone modification, the particle size of nano-silicon dioxide is 25 nanometers, accounting for 1.8% of the total mass of the raw materials.

[0052] Gel treatment: The system after the introduction of the nano-enhancer is subjected to gel treatment. The temperature is lowered to 23°C and the pH value is adjusted to 6.3. Calcium chloride, a gelling agent, is added, accounting for 1.3% of the total mass of the raw materials.

[0053] Drying and molding: Supercritical drying method is used, and the drying medium is carbon dioxide. The drying temperature is controlled at 43°C and the pressure is 9.5MPa.

[0054] Application: In the application of thermal insulation materials, the thermal conductivity of the aerogel is 0.024W / (m·K), which can be used for thermal insulation in the industrial field. In the application of sound-absorbing materials, the porosity is 88%, which is suitable for sound absorption in some places with high noise requirements. In the application of adsorption materials, the specific surface area is 520m 2 / g, can effectively adsorb pollutants in the environment.

[0055] Embodiment 2

[0056] Raw material preparation: Select a water-based polyurethane emulsion with a solid content of 38%. Select an organic silicon monomer containing two vinyl groups. Prepare a catalyst, dibutyltin dilaurate, accounting for 0.25% of the total mass of the raw materials, and a crosslinking agent, aziridine, accounting for 0.8% of the total mass of the raw materials.

[0057] Pretreatment: The aqueous polyurethane emulsion was subjected to ultrasonic dispersion treatment, with the ultrasonic power set to 280 W and the duration being 28 minutes.

[0058] Silicone modification: Add silicone monomer to the pre-treated waterborne polyurethane emulsion. The reaction was carried out at a temperature of 75°C and a stirring speed of 190 rpm for 4.2 hours.

[0059] Introducing nano-enhancer: Adding nano-silicon dioxide into the system after silicone modification, the particle size of nano-silicon dioxide is 45 nanometers, accounting for 2.5% of the total mass of the raw materials.

[0060] Gel treatment: The system after the introduction of the nano-enhancer is subjected to gel treatment. The temperature is lowered to 28°C and the pH value is adjusted to 6.7. Calcium chloride, a gelling agent, is added, accounting for 1.8% of the total mass of the raw materials.

[0061] Drying and molding: Supercritical drying method is used, and the drying medium is carbon dioxide. The drying temperature is controlled at 48°C and the pressure is 11MPa.

[0062] Application: In the application of thermal insulation materials, the thermal conductivity of the aerogel is 0.022W / (m·K), which can be used in the field of building energy conservation. In the application of sound-absorbing materials, the porosity is 92%, which can be used for sound absorption and noise reduction in places such as concert halls. In the application of adsorption materials, the specific surface area is 580m 2 / g, can be used to treat industrial wastewater.

[0063] Embodiment 3

[0064] Raw material preparation: Select water-based polyurethane emulsion with a solid content of 36%. Select an organosilicon polymer with a molecular weight of 1800. Prepare the catalyst dibutyltin dilaurate, accounting for 0.18% of the total mass of the raw materials, and the cross-linking agent aziridine, accounting for 0.75% of the total mass of the raw materials.

[0065] Pretreatment: The aqueous polyurethane emulsion was subjected to ultrasonic dispersion treatment, with the ultrasonic power set to 260 W and the duration being 26 minutes.

[0066] Silicone modification: Add silicone polymer to the pre-treated waterborne polyurethane emulsion. The reaction is carried out at a temperature of 72°C and a stirring speed of 185 rpm for 4 hours.

[0067] Introducing nano-enhancer: Adding nano-silicon dioxide into the system after silicone modification, the particle size of nano-silicon dioxide is 38 nanometers, accounting for 2.2% of the total mass of the raw materials.

[0068] Gel treatment: The system after the introduction of the nano-enhancer is subjected to gel treatment. The temperature is lowered to 26°C and the pH value is adjusted to 6.6. Calcium chloride, a gelling agent, is added, accounting for 1.6% of the total mass of the raw materials.

[0069] Drying and molding: Supercritical drying method is used, and the drying medium is carbon dioxide. The drying temperature is controlled at 46°C and the pressure is 10.5MPa.

[0070] Application: In the application of thermal insulation materials, the thermal conductivity of the aerogel is 0.0235W / (m·K), which can be used for heat dissipation protection of electronic equipment. In the application of sound-absorbing materials, the porosity is 90%, which can be used for noise reduction in factory workshops. In the application of adsorption materials, the specific surface area is 560m 2 / g, can be used for air purification.

[0071]

[0072] In terms of raw materials, waterborne polyurethane emulsions have different solid contents, silicones are divided into polymers and monomers with different molecular weights or vinyl numbers, and the proportions of catalysts and crosslinkers also vary. These differences affect the performance of aerogels, such as solid content affecting reaction stability, and the type of silicone determines the degree of bonding with waterborne polyurethane and the properties imparted.

[0073] In terms of process parameters, ultrasonic power and time affect the dispersion degree of emulsion particles; the temperature, stirring speed and reaction time of silicone modification affect the degree of grafting; the particle size and proportion of nano-silica, the temperature of gelation treatment, pH value and the proportion of calcium chloride determine the stability of the gel structure; supercritical drying temperature and pressure affect the solvent removal efficiency and aerogel quality.

[0074] In terms of application performance, the three embodiments have different thermal conductivity, porosity and specific surface area in the application of heat insulation, sound absorption and adsorption materials. Embodiment 2 has the lowest thermal conductivity and better thermal insulation performance; the highest porosity and possibly better sound absorption performance; the larger specific surface area and possibly stronger adsorption performance. Different embodiments can be selected and optimized according to specific application requirements to meet the requirements of aerogel performance in different fields.

[0075] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can replace or change the technical solution and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a silicone-modified waterborne polyurethane aerogel, characterized in that: The following steps are involved: Raw material preparation: select water-based polyurethane emulsion with a solid content of 30%-40%, select vinyl-containing silicone monomers or silicone polymers with a molecular weight of 1000-3000 as the organosilicon compound, and prepare the catalyst dibutyltin dilaurate, accounting for 0.1%-0.3% of the total mass of the raw materials, and the cross-linking agent aziridine, accounting for 0.5%-1% of the total mass of the raw materials; Pretreatment: ultrasonic dispersion treatment of waterborne polyurethane emulsion, ultrasonic power is 200-300W, time is 20-30 minutes; Silicone modification: Add the silicone compound to the pre-treated aqueous polyurethane emulsion, react at a temperature of 60-80°C and a stirring speed of 150-200 rpm for 3-5 hours; Introducing nano-enhancers: Adding nano-silicon dioxide after silicone modification, the particle size of nano-silicon dioxide is 20-50 nanometers, accounting for 1%-3% of the total mass of the raw materials; Gel treatment: The system after the introduction of the nano-enhancer is subjected to gel treatment by lowering the temperature to 20-30°C, adjusting the pH value to 6-7, adding gelling agent calcium chloride, accounting for 1%-2% of the total mass of the raw materials, controlling the speed and degree of gelation, and forming a stable gel structure; Drying and molding: The supercritical drying method is adopted, the drying medium is carbon dioxide, the drying temperature is 40-50°C, and the pressure is 8-12MPa. The gel is dried to remove the solvent therein to form a silicone-modified waterborne polyurethane aerogel.

2. The method for preparing a silicone-modified waterborne polyurethane aerogel according to claim 1, characterized in that: The solid content of the aqueous polyurethane emulsion is in the range of 30%-40%.

3. The method for preparing a silicone-modified waterborne polyurethane aerogel according to claim 1, characterized in that: The organosilicon compound is an organosilicon monomer or an organosilicon polymer containing vinyl groups. When it is an organosilicon monomer, the number of vinyl groups in its molecular structure is not less than two, and when it is an organosilicon polymer, its molecular weight ranges from 1500 to 2500.

4. The method for preparing a silicone-modified waterborne polyurethane aerogel according to claim 1, characterized in that: The catalyst is dibutyltin dilaurate, accounting for 0.15%-0.25% of the total mass of the raw materials; the cross-linking agent is aziridine, accounting for 0.6%-0.8% of the total mass of the raw materials.

5. The method for preparing a silicone-modified waterborne polyurethane aerogel according to claim 1, characterized in that: During the silicone modification process, the reaction temperature is controlled at 65°C-75°C, the stirring speed is set at 160 rpm-180 rpm, and the reaction time is 3.5 hours-4.5 hours.

6. The method for preparing a silicone-modified waterborne polyurethane aerogel according to claim 1, characterized in that: In the step of introducing the nano-enhancer, the particle size of the nano-silicon dioxide is 25 nanometers to 45 nanometers, accounting for 1.5% to 2.5% of the total mass of the raw material.

7. The method for preparing a silicone-modified waterborne polyurethane aerogel according to claim 1, characterized in that: During the gelation process, the temperature is controlled at 22° C.-28° C., the pH value is adjusted to 6.2-6.8, and the added gelling agent calcium chloride accounts for 1.2%-1.8% of the total mass of the raw materials.

8. The method for preparing a silicone-modified waterborne polyurethane aerogel according to claim 1, characterized in that: When the supercritical drying method is used, the drying medium is carbon dioxide, the drying temperature is 42°C-48°C, and the pressure is 9MPa-11MPa.

9. An application of an organosilicon-modified waterborne polyurethane aerogel, using the method for preparing an organosilicon-modified waterborne polyurethane aerogel according to claims 1-8, characterized in that: The prepared organosilicon-modified waterborne polyurethane aerogel is applied in the fields of thermal insulation materials, sound-absorbing materials and adsorption materials.

10. The use of an organosilicon-modified waterborne polyurethane aerogel according to claim 9, characterized in that: In the application of thermal insulation materials, the aerogel has a low thermal conductivity coefficient, which is no higher than 0.025W / (m·K); In the application of sound-absorbing materials, the aerogel has a porous structure with a porosity between 85% and 95%; In the application of adsorption materials, the aerogel has a high specific surface area, which is not less than 500m 2 / g. .

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