A toughened composite aerogel felt and its preparation method

Abstract

The present invention relates to a toughened composite aerogel felt and a preparation method thereof, belonging to the technical field of thermal insulation materials. The aerogel felt is composed of a glass fiber cloth and a heat insulation layer. Among them, the heat insulation layer includes, by weight: 80-100 parts of a modified silicone resin, 25-40 parts of aerogel micropowder, 8-14 parts of titanium dioxide, 1.2-1.8 parts of a wetting agent, 0.5-0.7 parts of a leveling agent, and 30-40 parts of dilute acetic acid. The modified silicone resin uses amino silicone oil as the main material, forms branched carboxyl modification through chloroacetic acid substitution reaction, then undergoes sulfinyl chloride treatment with thionyl chloride, and then undergoes substitution with ureidopropyltriethoxysilane to form a modified structure of terminal triethoxysilane, which can condense with the hydroxyl groups on the surface of silica-based aerogel powder and glass fiber cloth, greatly improving the bonding strength between the aerogel powder and the glass fiber cloth. At the same time, it has a chelating effect on titanium dioxide, and cooperates with the aerogel to play a role in hindering heat conduction and heat radiation, thus having good heat insulation performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal insulation materials, and specifically relates to a toughened composite aerogel felt and a preparation method thereof. Background Art

[0002] Aerogel is a continuous three-dimensional network structure formed by the aggregation of nanoparticles at the nanoscale. Due to its special nanoscale micropores and framework structure, the efficiency of its thermal conductivity, convective heat transfer, and radiative heat transfer are all effectively restricted. Therefore, aerogel has a very low thermal conductivity and is the solid material with the lowest thermal conductivity in the world at present, and is widely used in thermal insulation materials. However, aerogel is a hard material and cannot be applied to complex construction surfaces.

[0003] Combining aerogel with fibers, and preparing aerogel felt materials through processes such as impregnating sol, gel, solvent replacement, and supercritical drying has a certain flexibility and can meet most construction requirements; the preparation process of this kind of aerogel felt is complex, with a long production cycle and high cost, and cannot meet industrial production. The production process of coating and forming gradually replaces the original process in the commercial field. For example, Chinese Patent Application CN106757781B discloses a preparation method of an aerogel heat insulation felt, which makes aerogel into powder, disperses it in a solvent and then sprays it on a glass felt, and obtains a flexible aerogel felt through needle punching forming; however, the bonding strength between the aerogel microparticles and the felt substrate and between the aerogel microparticles in this kind of felt material is low, and problems such as peeling and cracking are likely to occur during use, resulting in a serious deterioration of the heat insulation performance. Therefore, the present invention aims to prepare a toughened composite aerogel felt by a coating method. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, the purpose of the present invention is to provide a toughened composite aerogel felt and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A toughened composite aerogel felt, which is composed of a fiberglass cloth and a heat insulation layer. The heat insulation layer includes the following raw materials by weight:

[0007] 80 - 100 parts of modified silicone resin, 25 - 40 parts of aerogel micropowder, 8 - 14 parts of titanium dioxide, 1.2 - 1.8 parts of wetting agent, 0.5 - 0.7 parts of leveling agent, and 30 - 40 parts of dilute acetic acid;

[0008] The modified silicone resin is prepared by the following method:

[0009] Step A1: Preheat and mix chloroacetic acid and tetrahydrofuran, add a small amount of triethylamine and mix, introduce dry nitrogen for protection, control the temperature at 65 - 75 °C, apply mechanical stirring at 120 - 240 rpm, intermittently add amino silicone oil for reflux reaction, control the total addition reaction time of amino silicone oil to be 5 - 7 h, after the reaction, remove tetrahydrofuran by rotary evaporation under reduced pressure, then add deionized water for washing, centrifuge to remove the water layer, and dry in vacuum to obtain the matrix resin;

[0010] Further, the amino silicone oil is selected as a small molecular weight and low viscosity silicone oil. In this case, the DY - N323 type amino silicone oil provided by Shandong Dayi Chemical Co., Ltd. is selected;

[0011] Further, the dosage ratio of amino silicone oil, chloroacetic acid, triethylamine and tetrahydrofuran is 100 g : 0.25 - 0.32 mol : 20 - 30 mL : 150 - 200 mL. The amino substitution reaction between chloroacetic acid and the amino group in the amino silicone oil forms a branched carboxyl modification. At the same time, the formed nitrogen - oxygen structure can form a stable chelating effect on metal particles, strengthening the mechanical properties of the matrix.

[0012] Step A2: Mix thionyl chloride and dioxane, add the matrix resin and mix, heat up to 60 - 70 °C and stir - react for 30 - 40 min, rotary evaporate under reduced pressure until no residual thionyl chloride precipitates, cool down to room temperature, add benzene and mix, apply mechanical stirring at 120 - 180 rpm, protect with nitrogen and slowly add 3 - (triethoxysilyl)propylurea, control the total addition reaction time to be 15 - 20 h, after the reaction, rotary evaporate under reduced pressure to remove low - boiling substances including dioxane to obtain the modified silicone resin.

[0013] Further, the dosage ratio of the matrix resin, 3 - (triethoxysilyl)propylurea, thionyl chloride, dioxane and benzene is 100 g : 0.18 - 0.22 mol : 0.3 - 0.4 mol : 200 - 260 mL : 150 - 200 mL. Thionyl chloride acyl - chlorinates the carboxyl group introduced in the matrix resin, and then reacts with 3 - (triethoxysilyl)propylurea to introduce an ethoxysilane structure modification, which can condense with both fiberglass cloth and aerogel, making the felt material have good toughness.

[0014] A preparation method of a toughened composite aerogel felt, comprising the following steps:

[0015] Step S1: Mix the modified silicone resin, wetting agent, leveling agent and dilute acetic acid, heat up to 35 - 45 °C, apply mechanical stirring at 360 - 480 rpm, stir and hydrolyze for 50 - 70 min to obtain a casting solution;

[0016] Step S2: Stir the casting solution at 50 - 70 rpm, uniformly add the mixture of aerogel micropowder and titanium dioxide, control the addition mixing time to be 20 - 30 min to obtain a composite slurry;

[0017] Step S3: Immerse the tightly woven fiberglass cloth in an alkaline ethanol solution, drain it, scrape and coat the composite slurry layer by layer on the surface, place it in an atmosphere oven, control the atmosphere in the oven to be nitrogen and ammonia, the temperature to be 80 °C, and bake for 5 h. The composite slurry dries to form a heat insulation layer, and a toughened composite aerogel felt is obtained.

[0018] Further, the mass fraction of dilute acetic acid is 3.5 - 4.5%.

[0019] Further, the volume concentration of ammonia gas in the atmosphere oven during the drying process of the composite slurry is not less than 40%.

[0020] Further, both the wetting agent and the leveling agent are organosilicon-based products.

[0021] Advantages of the present invention:

[0022] The present invention discloses an aerogel felt with a composite structure, which uses fiberglass cloth as the base, aerogel micropowder and titanium dioxide as the heat-resistant and heat-insulating materials, and uses a self-made modified organosilicon resin as the bonding material to combine the heat-resistant and heat-insulating materials with the base. Compared with the traditional sol-gel method for preparing aerogel felt materials, the finished product preparation process is simpler, the production cycle is shorter, and the production efficiency can be greatly improved;

[0023] The modified organosilicon resin disclosed in the present invention uses aminopolysiloxane with a small molecular weight and low viscosity as the main material. Through chloroacetic acid substitution reaction, branched carboxyl modification is formed, and then through thionyl chloride chlorination treatment, and then substituted with ureidopropyltriethoxysilane to form a modified structure of terminal triethoxysilane; the molecular main chain of the modified organosilicon resin is a silicon-oxygen chain, which has good heat resistance, can meet the requirement that the aerogel felt maintains a stable shape at high temperature, and has good toughness after drying and film-forming; the terminal triethoxysilane structure of the modified organosilicon resin molecule hydrolyzes during the forming process of the felt, and can condense with the hydroxyl groups on the surface of the silica-based aerogel powder and fiberglass cloth, greatly improving the bonding strength between the aerogel powder and the fiberglass cloth, and it is not easy to break away and fail during use; the nitrogen-oxygen structure introduced during the chloroacetic acid substitution in the modified organosilicon resin molecule has a chelating effect on titanium dioxide, forms an anchoring effect on titanium dioxide, reduces the impact on the mechanical properties of the coating. At the same time, the modified organosilicon resin serves as a template to uniformly disperse titanium dioxide between the aerogel powder materials, and cooperates with the aerogel to play a role in hindering heat conduction and heat radiation, so as to have good heat insulation performance. Specific embodiments

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0025] Example 1

[0026] In this example, a toughened composite aerogel felt was prepared, and the specific implementation process is as follows:

[0027] 1) Preparation of modified silicone resin

[0028] Step A1: Take chloroacetic acid and tetrahydrofuran and mix them for feeding. Heat and stir at 60 rpm to dissolve chloroacetic acid in tetrahydrofuran. Then add a small amount of triethylamine and mix. Pass in high-purity dry nitrogen until a stable gas flow is discharged. Control the temperature at 65 °C and increase the mechanical stirring rate to 120 rpm. Divide the amino silicone oil into 4 portions and add the amino silicone oil in batches at intervals of 50 min. After complete addition, continue to stir and react at a constant temperature. Control the total addition reaction time of the amino silicone oil to be 7 h. After the reaction is completed, perform rotary evaporation under reduced pressure to quickly remove the low-boiling substances mainly composed of tetrahydrofuran. Then add 2 times the mass of deionized water to the rotary evaporation substrate and stir and wash at high speed. Centrifuge the washing liquid to remove the water layer and vacuum dry until no water is analyzed out to obtain the matrix resin. Among them, in the examples, small-molecular-weight and low-viscosity reactive amino silicone oil is used, with a viscosity of about 30 cP, an amine value of about 1 mmol / g, and a model of DY-N323, provided by Shandong Dayi Chemical Co., Ltd. The dosage ratio of amino silicone oil, chloroacetic acid, triethylamine, and tetrahydrofuran is 100 g: 0.25 mol: 20 mL: 150 mL.

[0029] Step A2: Take thionyl chloride and dioxane and mix them evenly. Add the matrix resin and mix. Raise the temperature to 60 °C and stir and react at 180 rpm for 40 min. Perform rotary evaporation under reduced pressure until no residual thionyl chloride precipitates. Cool to room temperature, add benzene and mix. Control the stirring rate at 120 rpm, pass in nitrogen for protection, and slowly add 3-(triethoxysilyl)propylurea in 8 h. Control the total addition reaction time to be 20 h. After the reaction is completed, perform rotary evaporation under reduced pressure to remove the low-boiling substances mainly composed of dioxane to obtain the modified silicone resin. Among them, the dosage ratio of matrix resin, 3-(triethoxysilyl)propylurea, thionyl chloride, dioxane, and benzene is 100 g: 0.18 mol: 0.3 mol: 200 mL: 1500 mL.

[0030] 2) Preparation of aerogel felt

[0031] Step S1: Prepare dilute acetic acid with a mass fraction of 3.5%. Feed and mix 85 parts of modified silicone resin, 1.2 parts of wetting agent, 0.7 part of leveling agent, and 32 parts of dilute acetic acid. Among them, in the examples, the wetting agent is all water-based silicone wetting agent with a model of ZY-8131, and the leveling agent is all silicone leveling agent with a model of AKN-1803. Raise the temperature of the mixture to 35 °C, apply mechanical stirring at 360 rpm, and stir and hydrolyze for 70 min to obtain the casting solution.

[0032] Step S2: Apply mechanical stirring to the casting solution at 50 rpm. Take 25 parts of aerogel micropowder and 14 parts of titanium dioxide and mix them. Then, uniformly add the mixed powder into the casting solution and mix for 30 min to obtain a composite slurry. Among them, the aerogel micropowder is all silica aerogel powder, the mode particle size is about 20 μm, the porosity is ≥95%, and the titanium dioxide is all selected from PFR-404 type titanium dioxide with a particle size of about 0.3 μm.

[0033] Step S3: Prepare an alkaline ethanol solution with a pH value of 10.0 and an ethanol mass fraction of 35%. Immerse the tightly woven fiberglass cloth in the alkaline ethanol solution for 12 h, take it out and drain for 2 h until there is no obvious dripping. Scrape the composite slurry on the surface, with the initial scraping thickness of 2.5 mm. Bake it in a 60°C tunnel furnace for 30 min. Then scrape the composite slurry again and control the thickness after the second scraping to be 4 mm. Place it in an atmosphere oven, control the atmosphere in the oven to be nitrogen and ammonia, with the ammonia volume concentration of 40% and the temperature of 80°C, and bake for 5 h. The composite slurry dries to form a heat insulation layer, and a toughened composite aerogel felt is obtained.

[0034] Example 2

[0035] The specific implementation process for preparing the toughened composite aerogel felt in this example is as follows:

[0036] 1) Prepare the modified silicone resin

[0037] Step A1: Take chloroacetic acid and tetrahydrofuran and mix them for feeding. Heat and stir with 60 rpm to dissolve the chloroacetic acid into the tetrahydrofuran. Then add a small amount of triethylamine and mix. Pass in high-purity dry nitrogen until a stable gas flow is discharged. Control the temperature at 75°C and increase the mechanical stirring rate to 240 rpm. Divide the amino silicone oil into 4 parts and add the amino silicone oil in batches at intervals of 30 min. After complete addition, continue to stir and react at a constant temperature. Control the total addition reaction time of the amino silicone oil to be 5 h. After the reaction, carry out rotary evaporation under reduced pressure to quickly remove the low-boiling substances mainly composed of tetrahydrofuran. Then add 2 times the mass of deionized water to the rotary evaporation substrate and stir and wash at high speed. Centrifuge the washing solution to remove the water layer and vacuum dry until no water is precipitated to obtain the matrix resin. Among them, the dosage ratio of amino silicone oil, chloroacetic acid, triethylamine and tetrahydrofuran is 100 g: 0.32 mol: 30 mL: 200 mL.

[0038] Step A2: Take thionyl chloride and dioxane, feed and mix them evenly, add the matrix resin and mix. Heat up to 70 °C, stir and react for 30 min with a stirring speed of 240 rpm. Rotate and evaporate under reduced pressure until no residual thionyl chloride precipitates. Cool down to room temperature, add benzene and mix evenly. Control the stirring rate at 180 rpm, introduce nitrogen for protection, slowly add 3-ureidopropyltriethoxysilane within 5 h, and control the total addition reaction time at 15 h. After the reaction, rotate and evaporate under reduced pressure to remove the low-boiling substances mainly composed of dioxane, and obtain the modified silicone resin. Among them, the dosage ratio of the matrix resin, 3-ureidopropyltriethoxysilane, thionyl chloride, dioxane and benzene is 100 g: 0.22 mol: 0.4 mol: 260 mL: 200 mL.

[0039] 2) Preparation of aerogel felt

[0040] Step S1: Prepare a dilute acetic acid with a mass fraction of 4.5%. Feed and mix 100 parts of the modified silicone resin, 1.8 parts of wetting agent, 0.6 part of leveling agent and 35 parts of dilute acetic acid. Heat up the mixture to 45 °C, apply mechanical stirring at 480 rpm, and stir and hydrolyze for 50 min to obtain a casting solution.

[0041] Step S2: Apply mechanical stirring at 70 rpm to the casting solution. Take 40 parts of aerogel micropowder and 8 parts of titanium dioxide and mix them. Then, uniformly add the mixed powder into the casting solution and mix for 20 min to obtain a composite slurry.

[0042] Step S3: Prepare an alkaline ethanol solution with a pH value of 10.0 and an ethanol mass fraction of 35%. Immerse the tightly woven fiberglass cloth in the alkaline ethanol solution for 12 h, take it out and drain it for 2 h until there is no obvious dripping. Apply the composite slurry on the surface by scraping twice, place it in an atmosphere oven, control the atmosphere in the oven to be nitrogen and ammonia, and the volume concentration of ammonia is 50%, the temperature is 80 °C, and bake for 5 h. The composite slurry dries to form a heat insulation layer, and a toughened composite aerogel felt is obtained.

[0043] Example 3

[0044] In this example, a toughened composite aerogel felt is prepared, and the specific implementation process is as follows:

[0045] 1) Preparation of modified silicone resin

[0046] Step A1: Take chloroacetic acid and tetrahydrofuran for mixed feeding, heat and stir at 60 rpm. Dissolve chloroacetic acid in tetrahydrofuran, then add a small amount of triethylamine and mix. Pass in high-purity dry nitrogen until a stable gas flow is discharged. Control the temperature at 70 °C, increase the mechanical stirring rate to 180 rpm. Divide the amino silicone oil into 4 portions and add the amino silicone oil in batches at intervals of 40 min. After complete addition, continue stirring and reacting at a constant temperature. Control the total addition reaction time of the amino silicone oil to be 6 h. After the reaction is completed, carry out rotary evaporation under reduced pressure to quickly remove the low-boiling substances mainly composed of tetrahydrofuran. Then add deionized water with a mass 2 times that of the rotary evaporation substrate and stir at high speed for mixing and washing. Centrifuge the mixed washing liquid, remove the water layer, and dry in vacuum until no water is analyzed out to obtain the matrix resin. Among them, the dosage ratio of amino silicone oil, chloroacetic acid, triethylamine and tetrahydrofuran is 100 g: 0.28 mol: 25 mL: 160 mL.

[0047] Step A2: Take thionyl chloride and dioxane for feeding and mixing, add the matrix resin and mix. Heat up to 65 °C and stir and react at 180 rpm for 40 min. Carry out rotary evaporation under reduced pressure until no residual thionyl chloride precipitates. Cool down to room temperature, add benzene and mix. Control the stirring rate at 120 rpm, pass in nitrogen for protection, and slowly add 3-aminopropyltriethoxysilane in 6 h. Control the total addition reaction time to be 18 h. After the reaction is completed, carry out rotary evaporation under reduced pressure to remove the low-boiling substances mainly composed of dioxane to obtain the modified silicone resin. Among them, the dosage ratio of matrix resin, 3-aminopropyltriethoxysilane, thionyl chloride, dioxane and benzene is 100 g: 0.2 mol: 0.35 mol: 240 mL: 160 mL.

[0048] 2) Preparation of aerogel felt

[0049] Step S1: Prepare a dilute acetic acid with a mass fraction of 4.0%. Feed and mix 90 parts of the modified silicone resin, 1.6 parts of wetting agent, 0.5 part of leveling agent and 40 parts of dilute acetic acid. Heat the mixture to 40 °C, apply mechanical stirring at 420 rpm, and stir and hydrolyze for 55 min to obtain the casting solution.

[0050] Step S2: Apply mechanical stirring at 70 rpm to the casting solution. Take 32 parts of aerogel micropowder and 12 parts of titanium dioxide and mix them. Then uniformly add the mixed powder to the casting solution and mix for 20 - 30 min to obtain the composite slurry.

[0051] Step S3: Prepare an alkaline ethanol solution with a pH value of 10.0 and an ethanol mass fraction of 35%. Immerse the tightly woven fiberglass cloth in the alkaline ethanol solution for 12 h, take it out and drain for 2 h until there is no obvious dripping. Apply the composite slurry on the surface by scraping twice, place it in an atmosphere oven, control the atmosphere in the oven to be nitrogen and ammonia, and the ammonia volume concentration is 45%, the temperature is 80 °C, and bake for 5 h. The composite slurry dries to form a heat-insulating layer to obtain the toughened composite aerogel felt.

[0052] Example 4

[0053] In this example, a toughened composite aerogel felt was prepared, and the specific implementation process is as follows:

[0054] 1) Preparation of modified silicone resin

[0055] Step A1: Take chloroacetic acid and tetrahydrofuran and mix them for feeding. Heat and stir with 60 rpm to dissolve chloroacetic acid in tetrahydrofuran. Then add a small amount of triethylamine and mix. Pass in high-purity dry nitrogen until a stable gas flow is discharged. Control the temperature at 72 °C and increase the mechanical stirring rate to 180 rpm. Divide the amino silicone oil into 4 portions and add the amino silicone oil in batches at intervals of 50 min. After complete addition, continue stirring and reacting at a constant temperature. Control the total addition reaction time of the amino silicone oil to be 6 h. After the reaction is completed, carry out rotary evaporation under reduced pressure to quickly remove the low-boiling substances mainly composed of tetrahydrofuran. Then add 2 times the mass of deionized water to the rotary evaporation substrate and stir and wash at high speed. Centrifuge the washing liquid to remove the water layer and vacuum dry until no water is analyzed out to obtain the matrix resin. Among them, the dosage ratio of amino silicone oil, chloroacetic acid, triethylamine and tetrahydrofuran is 100 g: 0.3 mol: 26 mL: 180 mL.

[0056] Step A2: Take thionyl chloride and dioxane and mix them evenly. Add the matrix resin and mix. Heat up to 65 °C and stir and react with 240 rpm for 40 min. Carry out rotary evaporation under reduced pressure until no residual thionyl chloride precipitates. Cool down to room temperature, add benzene and mix. Control the stirring rate at 180 rpm, pass in nitrogen for protection, and slowly add 3-(triethoxysilyl)propylurea in 7 h. Control the total addition reaction time to be 16 h. After the reaction is completed, carry out rotary evaporation under reduced pressure to remove the low-boiling substances mainly composed of dioxane to obtain the modified silicone resin. Among them, the dosage ratio of matrix resin, 3-(triethoxysilyl)propylurea, thionyl chloride, dioxane and benzene is 100 g: 0.2 mol: 0.35 mol: 220 mL: 200 mL.

[0057] 2) Preparation of aerogel felt

[0058] Step S1: Prepare a dilute acetic acid with a mass fraction of 4.5%. Feed 80 parts of modified silicone resin, 1.5 parts of wetting agent, 0.6 part of leveling agent and 30 parts of dilute acetic acid and mix them. Heat the mixture to 45 °C and apply mechanical stirring at 360 rpm. Stir and hydrolyze for 65 min to obtain a casting solution.

[0059] Step S2: Apply mechanical stirring at 70 rpm to the casting solution. Take 28 parts of aerogel micropowder and 11 parts of titanium dioxide and mix them. Then uniformly add the mixed powder to the casting solution and mix for 30 min to obtain a composite slurry.

[0060] Step S3: Prepare an alkaline ethanol solution with a pH value of 10.0 and an ethanol mass fraction of 35%. Immerse the tightly woven fiberglass cloth in the alkaline ethanol solution for 12 h, take it out and drain for 2 h until there is no obvious dripping. Apply the composite paste twice on the surface, place it in an atmosphere oven, control the atmosphere in the oven to be nitrogen and ammonia, with the ammonia volume concentration being 45%, the temperature being 80 °C, and bake for 5 h. The composite paste dries to form a heat insulation layer, and a toughened composite aerogel felt is obtained.

[0061] Comparative example

[0062] In this comparative example, a commercially available aerogel thermal insulation slurry was used to make a felt material. The substrate was the same tightly woven fiberglass cloth as in the example, and the slurry was the aerogel slurry of a certain new material technology company in Jiangsu. The coating thickness was 4 mm, and the drying method was drying with nitrogen at 60 °C for 24 h.

[0063] Take the aerogel felts prepared in Examples 1 - 4 and the comparative example, and refer to the GB / T10295 - 2008 standard for the room temperature thermal conductivity test, refer to the GB / T 10294 - 2008 standard for the thermal conductivity test at 100 °C, and refer to GB / T2792 - 2014 for the peel test. Clamp the aerogel felt with a 3 cm steel roller, and the single - fold angle is 120 ° until visible cracks appear on the surface, record the number of folding times. The specific test data are shown in Table 1:

[0064] Table 1

[0065]

[0066]

[0067] It can be seen from the data in Table 1 that for the aerogel felt prepared by the present invention, the thermal conductivity at room temperature is similar to that of the comparative example, the thermal conductivity at 100 °C is slightly lower than that of the comparative example, the peel strength reaches 11.7 - 13.4 N / 25 mm, which is significantly higher than that of the comparative example, and the number of 120 ° folding times reaches 170 - 225 times, which is significantly better than that of the comparative example.

[0068] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above - mentioned terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0069] The above content is only an example and illustration of the present invention. Those skilled in the art to which the present technology pertains can make various modifications or supplements to the described specific embodiments, or use similar methods for substitution. As long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A toughened composite aerogel felt, which is composed of a fiberglass cloth and a heat insulation layer, is characterized in that, The thermal insulation layer includes, by weight parts: 80 - 100 parts of modified silicone resin, 25 - 40 parts of aerogel micropowder, 8 - 14 parts of titanium dioxide, 1.2 - 1.8 parts of wetting agent, 0.5 - 0.7 parts of leveling agent, and 30 - 40 parts of dilute acetic acid; The modified silicone resin is prepared by the following method: Step A1: Pre - heat and mix chloroacetic acid and tetrahydrofuran, add triethylamine and mix, introduce dry nitrogen for protection, control the temperature at 65 - 75 °C, stir and intermittently add amino silicone oil for reflux reaction, control the total addition reaction time to be 5 - 7 h, after the reaction ends, carry out rotary evaporation under reduced pressure, then add deionized water for washing, centrifuge to remove the water layer, and dry under vacuum to obtain the matrix resin. Among them, the amino silicone oil is DY - N323 type small - molecular - weight and low - viscosity silicone oil, and the dosage ratio of amino silicone oil, chloroacetic acid, triethylamine, and tetrahydrofuran is 100 g: 0.25 - 0.32 mol: 20 - 30 mL: 150 - 200 mL; Step A2: Mix thionyl chloride and dioxane, add the matrix resin and mix, heat up to 60 - 70 °C and stir for reaction for 30 - 40 min, carry out rotary evaporation under reduced pressure until no residual thionyl chloride precipitates, cool down to room temperature, add benzene and mix, protect with nitrogen, stir and slowly add ureidopropyltriethoxysilane, control the total addition reaction time to be 15 - 20 h, after the reaction ends, carry out rotary evaporation under reduced pressure to obtain the modified silicone resin. Among them, the dosage ratio of matrix resin, ureidopropyltriethoxysilane, thionyl chloride, dioxane, and benzene is 100 g: 0.18 - 0.22 mol: 0.3 - 0.4 mol: 200 - 260 mL: 150 - 200 mL.

2. The preparation method of a toughened composite aerogel felt according to claim 1, characterized in that, It includes the following steps: Step S1: Mix the modified silicone resin, wetting agent, leveling agent, and dilute acetic acid, heat up to 35 - 45 °C, stir and hydrolyze for 50 - 70 min to obtain a casting solution; Step S2: Stir the casting solution at 50 - 70 rpm, uniformly add the mixture of aerogel micropowder and titanium dioxide, control the addition mixing time to be 20 - 30 min to obtain a composite slurry; Step S3: Immerse the tightly woven fiberglass cloth in an alkaline ethanol solution, drain it, and then scrape - coat the composite slurry layer - by - layer on the surface, place it in an atmosphere oven, control the atmosphere in the oven to be nitrogen and ammonia, the temperature is 80 °C, bake for 5 h, the composite slurry dries to form a thermal insulation layer, and a toughened composite aerogel felt is obtained.

3. The preparation method of a toughened composite aerogel felt according to claim 2, characterized in that, The mass fraction of the dilute acetic acid is 3.5 - 4.5%.

4. The preparation method of a toughened composite aerogel felt according to claim 2, characterized in that, During the drying process of the composite slurry, the volume concentration of ammonia gas in the atmosphere oven is not less than 40%.

5. The preparation method of a toughened composite aerogel felt according to claim 2, characterized in that, The aerogel micropowder is silica aerogel.

6. The preparation method of a toughened composite aerogel felt according to claim 2, characterized in that, Both the wetting agent and the leveling agent are silicone matrices.

Images