Water-based ablation heat-proof coating as well as preparation method and application thereof

Abstract

The invention relates to a water-based ablation heat-proof coating as well as a preparation method and application thereof, and belongs to the technical field of heat-proof coatings, the water-based ablation heat-proof coating is prepared by taking linear polysiloxane emulsion as a resin matrix, adding hyperbranched organosilicon polymer, fiber filler and other functional components for compounding, taking water as a dispersing agent, and preparing the water-based ablation heat-proof coating. The water-based ablation heat-proof coating is obtained by coating the surface of a base body with the water-based ablation heat-proof coating and curing at the room temperature, and the coating is safe, environmentally friendly, low in cost and excellent in heat-proof performance, has excellent mechanical strength and bonding strength, passes ablation examination of a quartz lamp with the highest heat flux of 370 kW / m < 2 >, can be used for the surface of a fairing of a carrier rocket, and can be applied to the surface of the fairing of the carrier rocket. Therefore, pneumatic heating in the flight process is resisted.

Description

Technical Field

[0001] The invention relates to a water-based ablative heat-resistant coating and a preparation method and application thereof, which can be used for aerodynamic heat protection of the outer surface of a launch vehicle fairing and belongs to the technical field of heat-resistant coatings. Background Art

[0002] The fairing is an important structural component of the launch vehicle. It faces a harsh aerodynamic heating environment during the flight of the rocket. Due to the lightweight requirements of the launch vehicle, composite materials are generally used as the structural material of the fairing. Their temperature resistance is low, which may cause structural failure in the aerodynamic heating environment. It is necessary to use a thermal protection coating for the thermal protection of the fairing. Traditional thermal protection coatings mostly use 120# gasoline as a diluent. The coating process not only has great safety hazards, but also brings great pressure to the environment. In addition, the large-scale use of organic solvents also brings serious harm to the health of operators. Therefore, it is urgent to develop a water-based ablative thermal protection coating that uses water as a diluent and has good ablative heat protection capabilities to meet the use requirements of the launch vehicle fairing. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and to provide a water-based ablative thermal protection coating and a preparation method and application thereof, which can meet the thermal protection requirements of aerodynamic heating conditions, while realizing the transformation of the diluent from organic solvent to water, thereby eliminating the safety hazards in the existing thermal protection coating coating process and alleviating environmental pressure.

[0004] The technical solution of the present invention is:

[0005] A water-based ablative heat-resistant coating, the raw materials of the coating include the following components in parts by mass:

[0006]

[0007]

[0008] The structural formula of the hyperbranched organosilicon polymer is as follows:

[0009]

[0010] Among them, R1 is

[0011] R2 is methyl, ethyl or

[0012] R3 is phenyl or

[0013] The diluent is deionized water.

[0014] In the above-mentioned water-based ablation heat-resistant coating, the preparation method of the hyperbranched organosilicon polymer comprises:

[0015] In a nitrogen atmosphere at 4-6°C, silane A, silane B and silane C are dissolved in anhydrous methanol, deionized water and dilute hydrochloric acid are slowly added dropwise thereto, the pH value of the solution is adjusted to 2.8-3.2, and the reaction is carried out for 2-3 hours; the reaction temperature is adjusted to 60-65°C, the hydrolysis product of hexamethyldisiloxane is slowly added dropwise to the above solution, and the reaction is carried out for 8-12 hours to obtain an emulsion; after standing, filtering and vacuum drying, a hyperbranched organosilicon polymer is obtained;

[0016] The molar ratio of the silane A, silane B, silane C and the hydrolyzate of hexamethyldisiloxane is 1:1-5:0.5-2:2-6; 0.02-0.04 mol of silane A is added to every 100 ml of anhydrous methanol.

[0017] In the above-mentioned water-based ablation anti-thermal coating, the silane A is γ-glycidyloxypropyl trimethoxysilane or γ-glycidyloxypropyl triethoxysilane; the silane B is one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane or ethyltriethoxysilane; the silane C is one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, phenyltrimethoxysilane or phenyltriethoxysilane.

[0018] In the above-mentioned water-based ablation and heat-resistant coating, the terminal groups of the polysiloxane in the linear polysiloxane emulsion are hydroxyl groups, the side groups are one or more of methyl, ethyl or phenyl groups, and the number average molecular weight is 10,000 to 60,000.

[0019] In the above water-based ablation and heat-resistant coating, more than 50% of the polysiloxane side groups in the linear polysiloxane emulsion are methyl groups.

[0020] In the above-mentioned water-based ablative heat-resistant coating, the preparation method of the linear polysiloxane emulsion is as follows: using the phase transition method, firstly, the polysiloxane and the emulsifier are stirred at a low speed of 400 to 600 rpm, and a certain amount of deionized water is slowly dripped therein while maintaining the low-speed stirring, and the stirring is maintained for 10 to 30 minutes; then the stirring speed is increased to above 3000 rpm, and the remaining deionized water is quickly added, and the stirring is carried out for more than 30 minutes to obtain the linear polysiloxane emulsion.

[0021] In the above water-based ablation heat-resistant coating, the mass ratio of the polysiloxane, emulsifier and deionized water is 100:3-8:66-400; the amount of deionized water added for the first time is 20-50% of the mass of the polysiloxane.

[0022] In the above water-based ablation and heat-resistant coating, the solid content of the linear polysiloxane emulsion is 20-60%.

[0023] In the above-mentioned water-based ablative heat-resistant coating, the fiber is one or more of quartz fiber, high-silica fiber or aramid fiber; the ablation-resistant filler is one or more of zirconium oxide, titanium oxide, mica powder or kaolin.

[0024] In the above-mentioned water-based ablative heat-resistant coating, the auxiliary agent is one or more of an anti-settling agent, a leveling agent, a wetting agent or a dispersant; and the catalyst is one or a mixture of two of dibutyltin dilaurate or tetrabutyl titanate.

[0025] The method for preparing the above-mentioned water-based ablative heat-resistant coating comprises:

[0026] (1) mixing a linear polysiloxane emulsion and a hyperbranched silicone polymer according to a ratio, and dispersing them using a high-speed disperser to obtain a resin mixture;

[0027] (2) mixing the resin mixture, fiber, ablation-resistant filler, additive and diluent according to a proportion, and dispersing them using a high-speed disperser to obtain a coating composition;

[0028] (3) After adding the catalyst and stirring evenly, the coating composition is evenly coated on the surface of the substrate, with a single coating thickness of no more than 0.2 mm and an interval time of no less than 2 h. After the overall coating is completed, it is cured at room temperature for more than 72 h to obtain a water-based ablation and heat-resistant coating.

[0029] In the above-mentioned method for preparing the water-based ablative heat-resistant coating, the dispersing speed of the high-speed disperser is 500-800 rpm; the coating method includes brushing, spraying, scraping or roller coating.

[0030] Application of the above-mentioned water-based ablative thermal protection coating on the outer surface of the launch vehicle fairing.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] (1) The water-based ablation heat-resistant coating in the embodiment of the present invention uses a linear polysiloxane emulsion as a resin matrix, and is compounded with functional components such as a hyperbranched silicone polymer and a fiber filler, and uses water as a dispersant to obtain a water-based ablation heat-resistant coating. The water-based ablation heat-resistant coating is obtained by coating it on the surface of the substrate and curing it at room temperature. This coating is safe, environmentally friendly, low-cost, and has excellent heat-resistant performance. It has passed the highest heat flux density of 370kW / m 2 The quartz lamp ablation test can be used for the surface of the launch vehicle fairing to resist aerodynamic heating during flight.

[0033] (2) The water-based ablation and heat-resistant coating in the embodiment of the present invention is added with a hyperbranched silicone polymer with a special structure, which has excellent mechanical strength and bonding strength.

[0034] (3) The water-based ablation-resistant heat-resistant coating in the embodiment of the present invention uses linear polysiloxane as a matrix, has good elongation at break and environmental resistance, and achieves an increase in the cross-linking density of the cured product and an improvement in the ablation resistance through cross-linking and curing of the linear polysiloxane and the hyperbranched silicone polymer.

[0035] (4) The diluent used in the water-based ablation and heat-resistant coating in the embodiment of the present invention is deionized water, which not only has good adhesion but is also environmentally friendly, safe, and reduces costs by coordinating with various components. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the GPC curve of the linear polysiloxane in Example 1 of the present invention;

[0037] Figure 2 is the infrared spectrum of the hyperbranched organosilicon polymer in Example 1 of the present invention;

[0038] Figure 3 This is the thermal weight loss curve of the water-based ablation heat-resistant coating in Example 1 of the present invention;

[0039] Figure 4 This is a photo of the water-based ablation heat-resistant coating after the quartz lamp ablation test in Example 1 of the present invention. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0041] The present invention provides a water-based ablative heat-resistant coating whose raw materials are as follows:

[0042]

[0043] Among them, the structural formula of the hyperbranched silicone polymer is as follows:

[0044]

[0045] Where: R1 is

[0046] R2 is methyl, ethyl or

[0047] R3 is phenyl or

[0048] In an optional embodiment, the terminal groups of the polysiloxane in the linear polysiloxane emulsion are hydroxyl groups, the side groups are one or more of methyl, ethyl or phenyl groups, and the number average molecular weight is 10,000 to 60,000.

[0049] In an optional embodiment, preferably more than 50% of the polysiloxane side groups in the linear polysiloxane emulsion are methyl groups.

[0050] The linear polysiloxane emulsion is prepared by a phase transition method. First, the polysiloxane and the emulsifier are stirred at a low speed of 400 to 600 rpm, and a certain amount of deionized water is slowly dripped therein while maintaining the low-speed stirring, and the stirring is maintained for 10 to 30 minutes; then the stirring speed is increased to more than 3000 rpm, the remaining deionized water is quickly added, and the linear polysiloxane emulsion is obtained by stirring for more than 30 minutes.

[0051] In an optional embodiment, the mass ratio of polysiloxane, emulsifier and deionized water is 100:(3-8):(66-400); the amount of deionized water added for the first time is 20-50% of the mass of polysiloxane.

[0052] In an optional embodiment, the solid content of the linear polysiloxane emulsion is 20-60%.

[0053] The preparation method of the hyperbranched silicone polymer is as follows:

[0054] In a nitrogen atmosphere at 4-6°C, a certain amount of silane A, silane B and silane C are dissolved in anhydrous methanol, deionized water and dilute hydrochloric acid are slowly added dropwise thereto, the pH value of the solution is adjusted to 3±0.2, and the reaction is carried out for 2-3 hours; the reaction temperature is adjusted to 60-65°C, the hydrolysis product of hexamethyldisiloxane is slowly added dropwise into the above solution, and the reaction is carried out for 8-12 hours to obtain a white emulsion; after standing, filtering and vacuum drying, a hyperbranched organosilicon polymer is obtained.

[0055] In an optional embodiment, the molar ratio of silane A, silane B, silane C and the hydrolysis product of hexamethyldisiloxane is 1:(1-5):(0.5-2):(2-6); 0.02-0.04 mol of silane A is added to every 100 ml of anhydrous methanol.

[0056] In an optional embodiment, silane A is γ-glycidyloxypropyl trimethoxysilane or γ-glycidyloxypropyl triethoxysilane; silane B is one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane or ethyltriethoxysilane; silane C is one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, phenyltrimethoxysilane or phenyltriethoxysilane.

[0057] In an optional embodiment, the fiber is one or more of quartz fiber, high silica fiber or aramid fiber.

[0058] In an optional embodiment, the ablation-resistant filler is one or more of zirconium oxide, titanium oxide, mica powder or kaolin.

[0059] In an optional embodiment, the auxiliary agent is one or more of an anti-settling agent, a leveling agent, a wetting agent or a dispersant.

[0060] In an optional embodiment, the catalyst is one or a mixture of dibutyltin dilaurate or tetrabutyl titanate.

[0061] In an optional embodiment, the diluent is deionized water.

[0062] The preparation method of the water-based ablation heat-resistant coating of the present invention is as follows:

[0063] (1) Mix the linear polysiloxane emulsion and the hyperbranched silicone polymer according to the ratio, and disperse them using a high-speed disperser to obtain a resin mixture; the dispersion speed is 500 to 800 rpm.

[0064] (2) The resin mixture, fiber, ablation-resistant filler, additive and diluent are mixed according to the proportion, and dispersed using a high-speed disperser to obtain a coating composition; the dispersion speed is 500 to 800 rpm.

[0065] (3) After adding the catalyst and stirring evenly, the coating composition is evenly coated on the surface of the substrate by spraying, brushing, scraping or roller coating. The thickness of a single coating is not greater than 0.2 mm and the interval time is not less than 2 h. After the overall coating is completed, it is cured at room temperature for more than 72 h to obtain a water-based ablation and heat-resistant coating.

[0066] The invention discloses an application of the water-based ablative heat-resistant coating on the outer surface of a launch vehicle fairing.

[0067] Example 1

[0068] In the first step, 100 g of polysiloxane with a number average molecular weight of about 25,000 and a phenyl content of about 10% and 3 g of emulsifier Triton were stirred at 500 rpm, 50 g of deionized water was slowly added thereto while maintaining low-speed stirring, and stirring was continued for 20 min; then the stirring speed was increased to 3200 rpm, 250 g of deionized water was quickly added, and stirring was continued for 45 min to obtain a linear polysiloxane emulsion, such as Figure 1 Shown is the GPC curve of the linear polysiloxane in Example 1.

[0069] In the second step, 4.72 g of γ-glycidyloxypropyltrimethoxysilane, 13.6 g of methyltrimethoxysilane and 3.96 g of phenyltrimethoxysilane were dissolved in 100 mL of anhydrous methanol under nitrogen atmosphere and 5 ° C, and deionized water and dilute hydrochloric acid were slowly added thereto to adjust the pH of the solution to 3, and the reaction was carried out for 2.5 hours; the reaction temperature was adjusted to 60 ° C, and 6.48 g of the hydrolyzate of hexamethyldisiloxane was slowly added to the above solution, and the reaction was carried out for 10 hours to obtain a white emulsion; after standing, filtering and vacuum drying, a hyperbranched organosilicon polymer was obtained, such as Figure 2 Shown is the infrared spectrum of the hyperbranched organosilicon polymer in Example 1.

[0070] In the third step, 100 parts by mass of the linear polysiloxane emulsion is weighed, 2.5 parts by mass of the hyperbranched silicone polymer is added, and the mixture is dispersed at high speed for 20 minutes until the mixture is evenly dispersed to obtain a resin mixture.

[0071] The fourth step is to weigh 7.5 parts by mass of quartz fiber and 10 parts by mass of titanium oxide, as well as 0.1 parts by mass of anti-settling agent, 0.1 parts by mass of leveling agent and 60 parts by mass of deionized water and the resin mixture, and disperse them at 600 rpm for 20 minutes to obtain a coating mixture;

[0072] The fifth step is to add 0.25 parts by mass of dibutyltin dilaurate, spray the coating mixture evenly on the surface of the product, and let it stand at room temperature for 96 hours to obtain a water-based ablation and heat-resistant coating, and control the coating thickness to 3.5-4.0 mm.

[0073] like Figure 3 Shown is the thermal weight loss curve of the water-based ablation heat-resistant coating in Example 1; Figure 4 The photo shows the quartz lamp ablation test of the water-based ablation heat-resistant coating in Example 1. As can be seen from the figure, the maximum heat flux density is 370kW / m 2 After ablation with a quartz lamp, the water-based ablation heat-resistant coating has a smooth appearance without obvious ablation retreat or coating shedding problems.

[0074] Example 2

[0075] In the first step, 100 g of polysiloxane with a number average molecular weight of about 30,000 and methyl side groups and 3 g of emulsifier Triton are stirred at a speed of 500 rpm, 30 g of deionized water is slowly dripped into it while maintaining low-speed stirring, and stirring is continued for 20 minutes; then the stirring speed is increased to 3200 rpm, 120 g of deionized water is quickly added, and stirring is continued for 45 minutes to obtain a linear polysiloxane emulsion.

[0076] In the second step, under nitrogen atmosphere and 5°C, 7.08g of γ-glycidyloxypropyltrimethoxysilane, 13.6g of methyltrimethoxysilane and 3.96g of phenyltrimethoxysilane were dissolved in 100mL of anhydrous methanol, deionized water and dilute hydrochloric acid were slowly added dropwise, the pH value of the solution was adjusted to 3, and the reaction was carried out for 2.5h; the reaction temperature was adjusted to 60°C, 9.72g of the hydrolyzate of hexamethyldisiloxane was slowly added dropwise into the above solution, and the reaction was carried out for 10h to obtain a white emulsion; after standing, filtering and vacuum drying, a hyperbranched organosilicon polymer was obtained.

[0077] In the third step, 100 parts by mass of the linear polysiloxane emulsion is weighed, 6 parts by mass of the hyperbranched silicone polymer is added, and the mixture is dispersed at high speed for 20 minutes until the mixture is evenly dispersed to obtain a resin mixture.

[0078] The fourth step is to weigh 10 parts by mass of quartz fiber and 12 parts by mass of titanium oxide, as well as 0.2 parts by mass of anti-settling agent, 0.1 parts by mass of leveling agent, 0.1 parts by mass of dispersant and 80 parts by mass of deionized water and resin mixture, and disperse at 800 rpm for 20 minutes to obtain a coating mixture;

[0079] The fifth step is to add 0.6 parts by mass of tetrabutyl titanate, spray the coating mixture evenly on the surface of the product, and let it stand at room temperature for 96 hours to obtain a water-based ablation and heat-resistant coating, and control the coating thickness to 3.5-4.0 mm.

[0080] Example 3

[0081] In the first step, 100 g of polysiloxane with a number average molecular weight of about 30,000 and methyl side groups and 3 g of emulsifier Triton are stirred at a speed of 500 rpm, 20 g of deionized water is slowly dripped into it while maintaining low-speed stirring, and stirring is continued for 20 minutes; then the stirring speed is increased to 3600 rpm, 80 g of deionized water is quickly added, and stirring is continued for 45 minutes to obtain a linear polysiloxane emulsion.

[0082] In the second step, under nitrogen atmosphere and 5°C, 7.08g of γ-glycidyloxypropyltrimethoxysilane, 10.88g of methyltrimethoxysilane and 5.94g of phenyltrimethoxysilane were dissolved in 100mL of anhydrous methanol, deionized water and dilute hydrochloric acid were slowly added dropwise, the pH value of the solution was adjusted to 3, and the reaction was carried out for 2.5h; the reaction temperature was adjusted to 60°C, 9.72g of the hydrolyzate of hexamethyldisiloxane was slowly added dropwise into the above solution, and the reaction was carried out for 12h to obtain a white emulsion; after standing, filtering and vacuum drying, a hyperbranched organosilicon polymer was obtained.

[0083] The third step is to weigh 100 parts by mass of the linear polysiloxane emulsion, add 10 parts by mass of the hyperbranched silicone polymer, and disperse at high speed for 20 minutes to obtain a resin mixture.

[0084] The fourth step is to weigh 15 parts by mass of quartz fiber and 20 parts by mass of titanium oxide, as well as 0.2 parts by mass of anti-settling agent, 0.1 parts by mass of leveling agent, 0.1 parts by mass of wetting agent and 100 parts by mass of deionized water and the resin mixture, and disperse them at 700 rpm for 20 minutes to obtain a coating mixture;

[0085] The fifth step is to add 1 part of dibutyltin dilaurate, spray the coating mixture evenly on the surface of the product, and let it stand at room temperature for 96 hours to obtain a water-based ablation and heat-resistant coating, and control the coating thickness to 3.5-4.0 mm.

[0086] Table 1 Performance parameters of water-based ablative heat-resistant coatings in different embodiments

[0087] Example 1 Example 2 Example 3 Tensile shear strength (MPa) 1.24 1.62 1.86 Tensile strength(MPa) 1.84 2.02 2.30 Elongation at break (%) 86 72 62

[0088] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0089] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A water-based ablative heat-resistant coating, characterized in that: The raw materials of the coating include the following components in parts by weight: The structural formula of the hyperbranched organosilicon polymer is as follows: Among them, R1 is R2 is methyl, ethyl or R3 is phenyl or The diluent is deionized water.

2. The water-based ablative heat-resistant coating according to claim 1, characterized in that: The preparation method of the hyperbranched organosilicon polymer comprises: In a nitrogen atmosphere at 4-6°C, silane A, silane B and silane C are dissolved in anhydrous methanol, deionized water and dilute hydrochloric acid are slowly added dropwise thereto, the pH value of the solution is adjusted to 2.8-3.2, and the reaction is carried out for 2-3 hours; the reaction temperature is adjusted to 60-65°C, the hydrolysis product of hexamethyldisiloxane is slowly added dropwise to the above solution, and the reaction is carried out for 8-12 hours to obtain an emulsion; after standing, filtering and vacuum drying, a hyperbranched organosilicon polymer is obtained; The molar ratio of the silane A, silane B, silane C and the hydrolyzate of hexamethyldisiloxane is 1:1-5:0.5-2:2-6; 0.02-0.04 mol of silane A is added to every 100 ml of anhydrous methanol.

3. The water-based ablative heat-resistant coating according to claim 2, characterized in that: The silane A is γ-glycidyloxypropyl trimethoxysilane or γ-glycidyloxypropyl triethoxysilane; the silane B is one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, methyl trimethoxysilane, ethyl trimethoxysilane, methyl triethoxysilane or ethyl triethoxysilane; and the silane C is one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, phenyl trimethoxysilane or phenyl triethoxysilane.

4. The water-based ablative heat-resistant coating according to claim 1, characterized in that: The polysiloxane terminal groups in the linear polysiloxane emulsion are hydroxyl groups, the side groups are one or more of methyl, ethyl or phenyl groups, and the number average molecular weight is 10,000 to 60,000.

5. The water-based ablative heat-resistant coating according to claim 4, characterized in that: More than 50% of the polysiloxane side groups in the linear polysiloxane emulsion are methyl groups.

6. The water-based ablative heat-resistant coating according to claim 1, 4 or 5, characterized in that: The preparation method of the linear polysiloxane emulsion is as follows: using a phase transition method, firstly, polysiloxane and an emulsifier are stirred at a low speed of 400 to 600 rpm, a certain amount of deionized water is slowly dripped therein while maintaining the low-speed stirring, and the stirring is maintained for 10 to 30 minutes; then the stirring speed is increased to above 3000 rpm, the remaining deionized water is quickly added, and the linear polysiloxane emulsion is obtained by stirring for more than 30 minutes.

7. The water-based ablative heat-resistant coating according to claim 6, characterized in that: The mass ratio of the polysiloxane, the emulsifier and the deionized water is 100:3-8:66-400; the amount of the deionized water added for the first time is 20-50% of the mass of the polysiloxane.

8. The water-based ablative heat-resistant coating according to claim 6, characterized in that: The solid content of the linear polysiloxane emulsion is 20-60%.

9. The water-based ablative heat-resistant coating according to claim 1, characterized in that: The fiber is one or more of quartz fiber, high silica fiber or aramid fiber; The ablation-resistant filler is one or more of zirconium oxide, titanium oxide, mica powder or kaolin.

10. The water-based ablative heat-resistant coating according to claim 1, characterized in that: The auxiliary agent is one or more of an anti-settling agent, a leveling agent, a wetting agent or a dispersant; The catalyst is one of dibutyltin dilaurate and tetrabutyl titanate or a mixture of the two.

11. The method for preparing the water-based ablative heat-resistant coating according to any one of claims 1 to 10, characterized in that: include: (1) mixing a linear polysiloxane emulsion and a hyperbranched silicone polymer according to a ratio, and dispersing them using a high-speed disperser to obtain a resin mixture; (2) mixing the resin mixture, fiber, ablation-resistant filler, additive and diluent according to a proportion, and dispersing them using a high-speed disperser to obtain a coating composition; (3) After adding the catalyst and stirring evenly, the coating composition is evenly coated on the surface of the substrate, with a single coating thickness of no more than 0.2 mm and an interval time of no less than 2 h. After the overall coating is completed, it is cured at room temperature for more than 72 h to obtain a water-based ablation and heat-resistant coating.

12. The method for preparing the water-based ablative heat-resistant coating according to claim 11, characterized in that: The dispersion speed of the high-speed disperser is 500-800 rpm; the coating method includes brushing, spraying, scraping or roller coating.

13. Use of the water-based ablative heat-resistant coating according to any one of claims 1 to 10 on the outer surface of a launch vehicle fairing.

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