An environmentally friendly modified ultra-high temperature resistant silicone resin material for prepregs, a prepreg, a composite material, and a method for preparing the same.

Abstract

This invention provides an environmentally friendly modified ultra-high temperature resistant silicone resin material for prepregs, a prepreg, a composite material, and its preparation method. The method involves emulsifying phenyl silicone resin with a silane coupling agent, adding nanofillers and high-temperature resistant additives, and then adjusting the pH and performing vacuum degassing to obtain a highly stable waterborne silicone-based resin. A fiber fabric is impregnated with the resin, then gradient dried and subjected to high-temperature treatment (120°C) to form a prepreg, which is then laminated to obtain the composite material. The composite material exhibits a mass retention rate ≥85% and an ablation rate ≤0.05 mm / s in an argon atmosphere at 2000°C. This invention enhances the temperature resistance of silicone-based resins and offers excellent environmental performance (VOCs approaching zero), making it suitable for extreme operating conditions such as spacecraft thermal protection, nuclear reactor shielding, and ultra-high temperature sensor encapsulation. This environmentally friendly silicone resin system not only breaks through the temperature resistance limits of traditional materials but also achieves significant progress in environmental friendliness and cost-effectiveness, demonstrating significant technological breakthrough value and broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of resin-based thermal protection technology. Specifically, it relates to an environmentally friendly modified ultra-high temperature resistant silicone resin material for prepregs, prepregs, composite materials, and their preparation methods. Background Technology

[0002] With the rapid development of the aerospace and military industries, thermal protection materials are facing harsh operating environments, such as high temperature, high pressure, and high heat flux. Aerospace applications, operating at high altitudes and speeds, require external materials with excellent resistance to high and low temperatures and ozone. The development and demands of the aerospace industry have driven the development of advanced composite materials, which in turn have promoted progress in aerospace. The widespread use of advanced composite materials in the aerospace field has placed new demands on their performance.

[0003] Fiber-reinforced silicone resin composites are widely used in thermal protection components. Silicone resin is an organosilicon polymer with Si-O bonds as the main molecular chain and a high degree of branching. The Si-O bonds improve the oxidative stability of the polymer. Moreover, the hydrocarbon groups attached to the Si atoms, after being oxidized by heat, form even more stable Si-O-Si bonds, which can prevent the main chain from breaking and degrading. Organosilicon polymers have excellent heat resistance and weather resistance. They also have excellent flame retardancy, high insulation, and radiation protection properties, making them an essential supporting material for the aerospace industry. However, existing silicone resin prepregs have high viscosity and poor lay-up properties, which affects practical applications. Although traditional phenolic resin composites have short-term temperature resistance of 1000℃ and long-term temperature resistance of 500℃, they are no longer sufficient to meet the demands of modern technological development for the extreme performance of materials.

[0004] CN201610217852.5 discloses a silicone resin composition for prepregs, carbon fiber prepregs, and carbon fiber silicone resin composites. The silicone resin composition for prepregs includes silicone resin, phenolic resin, toughening agent, functional filler, coupling agent, and catalyst. The carbon fiber prepreg includes carbon fiber material and the silicone resin composition for prepregs. The carbon fiber silicone resin composite is obtained by curing the carbon fiber prepreg; the curing method includes filament winding, casting, or compression molding. This patent describes how the carbon fiber prepreg, after curing, yields a carbon fiber composite with excellent mechanical properties and high-temperature resistance. This invention pertains to the field of silicone resin carbon fiber composites.

[0005] Patent CN 113637287A discloses an aerospace ablation heat-resistant chopped fiber / phenolic high-density premix, a manual premixing preparation method, and its composite material. The aerospace ablation heat-resistant chopped fiber / phenolic high-density premix is ​​a semi-finished material with a certain degree of pre-curing, in a scattered state, and with fibers having no specific orientation. It is prepared by manual premixing of high-temperature resistant chopped fibers and high-carbon-residue phenolic resin under the action of additives, through processes such as yarn cutting, yarn drying, resin mixing, manual premixing, loosening, laying, air-drying, drying, testing, packaging, storage, and use. The aerospace ablation heat-resistant composite material is then prepared by molding the chopped fiber / phenolic high-density premix within a closed mold under specific temperature and pressure conditions. Summary of the Invention

[0006] To address the problems of insufficient temperature resistance (<2000℃), high production cost, and environmental pollution in existing phenolic resin composite materials, the inventors of this application, based on long-term research on resin-based thermal protection materials, propose an environmentally friendly modified ultra-high temperature resistant silicone resin material for prepregs, a prepreg, a composite material, and its preparation method. This method optimizes the resin network structure through an acidic waterborne process combined with ternary synergistic fillers (silicon carbide whiskers, zinc borate, and nano-inorganic material sol). The preparation method includes: emulsifying phenyl silicone resin with a silane coupling agent, adding nano-fillers and high-temperature resistant additives, adjusting the pH, and vacuum degassing to obtain a highly stable waterborne silicone-based resin; impregnating the fiber fabric with the resin and then gradient drying, followed by high-temperature treatment (120℃) under an inert atmosphere to form a pre-ceramicized transition layer, exhibiting a non-sticky but slightly tacky surface, facilitating lamination molding. The resulting laminated material exhibits a mass retention rate ≥85% and an ablation rate ≤0.05mm / s in an argon atmosphere at 2000℃. This invention boasts excellent environmental performance (VOCs approaching zero), making it suitable for extreme operating conditions such as spacecraft thermal protection, nuclear reactor shielding, and ultra-high temperature sensor encapsulation, while enhancing the temperature resistance of silicone-based resins. This environmentally friendly silicone resin system not only breaks through the temperature resistance limits of traditional materials but also achieves significant progress in environmental friendliness and cost-effectiveness, demonstrating remarkable technological breakthrough value and broad application prospects.

[0007] A method for preparing an environmentally friendly modified ultra-high temperature resistant silicone resin material for prepregs includes the following steps:

[0008] (1) Mix phenyl silicone resin with silane coupling agent, then add emulsifier and stir evenly; (2) Slowly add deionized water under high-speed shear to form a pre-emulsion, then add nano filler; (3) Adjust the pH of the system to 3.0±0.2 with pH adjuster, add high-temperature resistant additives and silicon carbide whiskers, and continue mixing under high-speed shear for 10-15 min; (4) Vacuum degassing under -0.1MPa conditions for 30-40 min to obtain a translucent to milky white waterborne silicone resin material; Phenyl silicone resin has higher heat resistance than other resins. The introduction of phenyl can improve the rigidity and stability of the molecular chain and maintain stable performance at higher temperatures.

[0009] The amount of nanofiller added is 10%-20% of the mass of phenyl silicone resin;

[0010] The high-temperature resistant additive is zinc borate, and the dosage is 5%-10% of the mass of phenyl silicone resin;

[0011] The amount of silicon carbide whiskers used is 15%-25% of the mass of phenyl silicone resin.

[0012] In step (1) above, the mass ratio of phenyl silicone resin to silane coupling agent is (9-10):1; preferably, the silane coupling agent is methacryloyloxypropyltrimethoxysilane.

[0013] The amount of emulsifier used is 3%-8% of the mass of the phenyl silicone resin; preferably, it is dodecylbenzene sulfonic acid or phosphate ester.

[0014] In step (2) above, the mass ratio of deionized water to phenyl silicone resin is 1:1; the nanofiller is selected from at least one sol of zirconium oxide, boron oxide or aluminum oxide; the nanofiller has a particle size of 10-30 nm and a solid content of 20%.

[0015] In step (3) above, the pH adjuster is a mixture of phosphoric acid and citric acid in a mass ratio of (1.5-2):1; this maintains the long-term stability of the system (viscosity change rate ≤5% within 6 months); the acidic environment promotes the hydrolysis and condensation of silicone resin, forming a dense network structure. The acidic pH environment enhances the density of resin hydrolysis crosslinking and reduces the high-temperature pyrolysis porosity (<5%).

[0016] Silicon carbide whiskers are acidified with concentrated nitric acid (65%) for 2-3 hours; the diameter of the silicon carbide whiskers is 0.1-1 μm, and the aspect ratio is ≥20. The 2-hour acidification with concentrated nitric acid (65%) enhances the chemical bonding between the silicon carbide whiskers and the resin interface, improving the material's toughness. Silicon carbide whiskers possess high strength and high modulus; when added to resin, they act as a reinforcing agent, effectively improving the resin's tensile strength, flexural strength, and hardness, enabling it to withstand greater external forces and loads, thus expanding the resin's application range.

[0017] In step (4), the solid content of the silicone resin material is 50% ± 2% and the viscosity is 1000-2000 mPa·s; in steps (2) and (3), the high-speed shearing conditions are 5000-8000 rpm. Except for step (1), high-speed shearing is used for mixing in all other steps.

[0018] A prepreg comprises a blended woven substrate and a resin material, wherein the blended woven substrate is completely impregnated with the resin material; the blended woven substrate is at least one of quartz fiber, silicon carbide fiber, and alumina fiber; and the resin material is an environmentally friendly modified ultra-high temperature resistant silicone resin material for prepregs prepared by the above preparation method.

[0019] The blended woven fabric substrate is obtained by the following method:

[0020] Raw material preparation: Select quartz fiber, silicon carbide fiber and alumina fiber, and mix them in a 1:1:1 ratio;

[0021] Spinning: The blended fibers are gently opened and combed, and then spun into yarn with a linear density of 40 tex using spinning equipment to ensure fiber integrity and yarn strength;

[0022] Weaving: On a high-precision loom, a twill weave is used with a warp density of 90 yarns / 10cm and a weft density of 85 yarns / 10cm to control tension and prevent fiber breakage;

[0023] Post-processing: Surface cleaning with air blowing and high-temperature heat treatment (200℃) are performed to improve the bonding strength between fibers, resulting in a basis weight of 220 g / m². 2 Surface density approximately 220 g / m³ 2 It is a high-performance blended woven fabric with high temperature resistance and high strength.

[0024] The preparation method of the prepreg includes the following steps: impregnating the blended fabric in a resin material (impregnation conditions: room temperature, 10-20 min), with a coating thickness of 0.1-0.4 mm and a resin content of 30%-40%; then performing gradient drying to evaporate moisture and allow the resin to undergo preliminary cross-linking, with volatile matter ≤1%; heating the prepreg to 120°C at 5°C / min, holding at that temperature for 2 h, and cooling to obtain a prepreg (single-layer prepreg), the surface of the obtained prepreg film is not sticky to the touch, the contact angle is ≥100°, but a small amount of tackiness is retained (peel force 0.1-0.5 N / cm); the resin material in the above prepreg has an impregnation rate of more than 98% in the above blended fabric.

[0025] The specific operation for impregnating the blended fabric is as follows: the blended fabric is immersed in the resin material at a uniform speed, and the impregnation time is maintained at 10 to 20 minutes to ensure that the resin fully wets the fabric fibers; then, the impregnated blended fabric is smoothly passed between two baffles with a spacing of 0.5 mm. By precisely adjusting the baffle spacing, the coating thickness is strictly controlled to be 0.1-0.4 mm, and the resin content in the fabric is maintained within the range of 30%-40%.

[0026] The volume fraction of resin material in the prepreg is 30%-40%.

[0027] The gradient drying process involves first drying at 60-65℃ for 10-15 minutes, followed by drying at 95-100℃ for 20-25 minutes. The initial low-temperature stage (e.g., 60℃) allows most of the free water to evaporate slowly, preventing microcracks caused by rapid resin shrinkage at high temperatures. When the temperature is subsequently raised to 100℃, the remaining moisture further evaporates, while simultaneously promoting the initial cross-linking of the resin molecular chains, forming a more uniform network structure.

[0028] After being heat-treated at 120℃, the prepreg becomes "non-sticky" but retains interlayer micro-adhesion, which facilitates the layup of composite materials; the uniform dispersion of nanofillers ensures a semi-transparent state (transmittance 40%-60%, wavelength 600nm).

[0029] The above-mentioned prepreg layup and curing can yield a composite material; the curing methods include filament winding and compression molding.

[0030] The specific preparation process of the winding molding is as follows:

[0031] a: Cut the prepreg into 20mm wide strips using a fabric cutter;

[0032] b: Wrap the cut fabric strips onto a winding machine at a speed of 80-100 r / min, alternating between spiral and circumferential windings, with the winding tension controlled at 5-10 N. After winding, place the product in an autoclave, heat to 600℃ at a rate of 5℃ / min, hold for 2 hours, then cure under 10 MPa pressure for 2 hours. After demolding, the composite material product is obtained.

[0033] The specific molding process is as follows:

[0034] c: Cut the prepreg into 300mm×200mm pieces using a fabric cutter, for a total of 20 pieces of prepreg;

[0035] d: Place 20 pieces of prepreg fabric into a molding die, heat to 600℃ at 5℃ / min, keep warm for 2 hours, then cure at 10MPa pressure for 2 hours. After the resin is completely cured, demold and cool to room temperature to obtain the composite material molded product.

[0036] A method for preparing a composite material includes the following processes: (i) providing a layered stack of prepreg; (ii) heating the layered stack of prepreg in an autoclave or molding die to allow the resin material system to flow and completely impregnate the woven substrate and form a cured resin matrix.

[0037] Step (i) involves cutting the prepreg into 300mm×200mm pieces and stacking 20 sheets to create a prepreg laminate (or cutting the prepreg to the required size and laying it layer by layer to obtain the stack).

[0038] The SiC-B2O3-XO composite ceramic phase formed by heat treatment at 600℃ after resin curing can resist thermal shock at 2000℃ and maintain a mass retention rate of ≥85% in an argon atmosphere at 2000℃.

[0039] This application has the following advantages over the prior art:

[0040] (1) This application optimizes the resin network structure by combining an acidic aqueous process with ternary synergistic fillers (silicon carbide whiskers, zinc borate, and nano-inorganic material sol). The zinc borate and nano-inorganic material sol in the ternary synergistic fillers work together with the silicon carbide whiskers to produce a synergistic effect. They can fill the gaps in the resin network, making the structure more compact, further improving the mechanical properties and wear resistance of the resin, while also enhancing its impact resistance, enabling it to better absorb energy and reduce damage when subjected to external impact. Silicon carbide whiskers and nano-inorganic material sol have good heat resistance, which can improve the thermal stability of the resin, allowing it to maintain good performance even at high temperatures, reducing thermal deformation and thermal decomposition. Zinc borate decomposes and absorbs heat when heated, playing a role in flame retardancy and heat insulation, further improving the resin's heat resistance, reducing its possibility of combustion at high temperatures, and improving safety in use.

[0041] (2) The addition of ternary synergistic fillers can reduce the coefficient of thermal expansion of the resin, making the resin more dimensionally stable when the temperature changes, reducing deformation and cracking caused by thermal expansion and contraction, and improving the bonding stability of the resin with other materials. It is suitable for occasions with high requirements for thermal stability.

[0042] (3) The prepreg of this application has the characteristics of being non-sticky but slightly tacky, which facilitates lamination molding. The resulting laminate (composite material) has a mass retention rate of ≥85% and an ablation rate of ≤0.05mm / s in an argon atmosphere at 2000℃.

[0043] (4) This application has excellent environmental performance. The VOC of the water-based system is close to zero (the acidic water-based process uses water as a solvent for the resin, replacing the traditional organic solvent. This greatly reduces the emission of volatile organic compounds (VOCs), reduces the pollution to the atmospheric environment, and also improves the working environment during production and use, reducing the harm to human health). The acidic conditions inhibit the growth of microorganisms and extend the emulsion's shelf life. It is suitable for extreme working conditions such as spacecraft thermal protection, nuclear reactor shielding, and ultra-high temperature sensor packaging, and enhances the temperature resistance of silicone resin. Detailed Implementation

[0044] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] The preparation methods of the environmentally friendly modified ultra-high temperature resistant silicone resin materials used in the following examples and comparative examples are all prepared by the following steps: (1) Mix phenyl silicone resin with silane coupling agent (methacryloyloxypropyltrimethoxysilane), and then add emulsifier (dodecylbenzenesulfonic acid) and stir evenly; (2) Slowly add deionized water under high speed shear to form a pre-emulsion, and then add nanofiller; (3) Adjust the pH of the system to 3.0±0.2 with pH adjuster, add zinc borate and silicon carbide whiskers, and continue mixing for 15 min under high speed shear; (4) Vacuum degassing for 35 min under -0.1 MPa conditions to obtain translucent to milky white waterborne silicone resin material G.

[0046] The nanofiller has a particle size of 20 nm and a solid content of 20%; the high-speed shearing condition is 6000 rpm; the silicon carbide whiskers are acidified with concentrated nitric acid (65%) for 3 h; the silicon carbide whisker diameter is 0.5 μm and the aspect ratio is ≥20.

[0047] The specific raw materials and reaction conditions used in the above preparation process are shown in Table 1 below:

[0048] Table 1

[0049]

[0050]

[0051] The prepreg made of environmentally friendly modified ultra-high temperature resistant silicone resin material G1 showed a viscosity change rate of 3.5% after 6 months of storage (initial viscosity 1721 mPa·s, 1773 mPa·s after 6 months), which meets the design requirement of "viscosity change rate ≤ 5%".

[0052] After 6 months of storage, the viscosity of G9 changed by 7.6% (initial viscosity 2432 mPa·s, 2617 mPa·s after 6 months).

[0053] The blended woven fabric substrate is obtained through the following method: Quartz fiber, silicon carbide fiber, and alumina fiber are selected and mixed in a 1:1:1 ratio; the blended fibers are gently opened and combed, and then spun into yarn with a linear density of 40 tex using spinning equipment to ensure fiber integrity and yarn strength; on a high-precision loom, a twill weave is used with a warp density of 90 yarns / 10cm and a weft density of 85 yarns / 10cm, and tension is controlled to prevent fiber breakage; the surface is cleaned by blowing dust and subjected to high-temperature heat treatment (200℃) to improve the bonding force between fibers, resulting in a weight of 220 g / m². 2 Surface density approximately 220 g / m³ 2 High-performance blended woven fabric.

[0054] The specific preparation process of prepreg H is as follows:

[0055] The woven fabric was impregnated in resin material (impregnation conditions: room temperature, 10-20 min), with coating thickness and resin content as follows: (H1, 0.1 mm, 30%; H2, 0.2 mm, 35%; H3, 0.4 mm, 40%; H4, 0.2 mm, 50%; H5, same thickness and resin content as H2, 0.2 mm, 35%). Gradient drying was then performed to evaporate moisture and allow the resin to undergo initial cross-linking, with volatile matter ≤1%. The prepreg was placed in an inert atmosphere furnace and heated to 120°C at 5°C / min, held for 2 hours to form a partially ceramized transition layer. After cooling, a single-layer prepreg was obtained. The surface of the prepreg film was not sticky, with a contact angle ≥100°, but retaining a slight amount of tackiness (peel force 0.1-0.5 N / cm). The resin material in the prepreg had an impregnation rate of over 98% in the woven fabric.

[0056] The gradient drying process is as follows: H1, first dry at 60℃ for 10 min, then dry at 100℃ for 20 min; H2, first dry at 65℃ for 15 min, then dry at 95℃ for 25 min; H3, the same gradient drying method as H1, first dry at 60℃ for 10 min, then dry at 100℃ for 20 min; H4, the same gradient drying method as H2, first dry at 65℃ for 15 min, then dry at 95℃ for 25 min; H5, directly dry at 95℃ for 40 min.

[0057] Prepreg H1 film contact angle: 105° (deionized water); interlayer peel strength: 0.3 N / cm (ASTM D3167); light transmittance: 55% (600nm wavelength, 1mm thickness).

[0058] The preparation process of composite materials, taking compression molding as an example, is as follows:

[0059] c: Cut the single-layer prepreg into 300mm×200mm pieces using a fabric cutter, for a total of 20 pieces of prepreg;

[0060] d: Place 20 pieces of prepreg fabric into a molding die, heat to 600℃ at 5℃ / min, keep warm for 2 hours, then cure at 10MPa pressure for 2 hours. After the resin is completely cured, demold and cool to room temperature to obtain composite material molded product F.

[0061] The specific environmentally friendly modified ultra-high temperature resistant silicone resin materials used in the prepregs of the above composite materials, along with the specific conditions for the prepreg preparation process, are shown in Table 2 below:

[0062] Table 2

[0063] Composite material molded products F F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 Resin material G G1 G2 G3 G4 G5 G6 G7 G8 G9 G1 G1 Prepreg H H1 H2 H3 H1 H1 H1 H1 H1 H1 H4 H5

[0064] Test example:

[0065] The performance of the above composite material F was tested, and the test methods and standards referred to GJB323A. The linear ablation rate was tested as follows: a sample with a size of Φ50×15mm was subjected to an oxy-acetylene flame ablation test (oxygen flow rate 1142L / h, acetylene flow rate 838L / h), with the distance between the sample and the nozzle being 20mm and the ablation time being 10s; the 2000℃ resistance test (mass retention rate %) in an argon environment at 2000℃ was obtained by DSC / TG testing; the flexural strength test referred to standard GB / T6569-86 (flexural strength test was performed after calcination at 2000℃ for 10min). The specific test results are shown in Table 3 below.

[0066] Table 3

[0067]

[0068]

[0069] According to the test results in Table 3, when phosphoric acid is used alone as a pH adjuster, the pH of the system cannot be kept stable at around 3, which affects the density of resin hydrolysis crosslinking and may increase the high-temperature pyrolysis porosity, resulting in a certain degree of reduction in mechanical properties. Without the use of the ternary synergistic filler (silicon carbide whiskers, zinc borate, and nano-inorganic material sol) of this application, the resin network structure cannot be optimized, and the resulting SiC-B2O3-XO composite ceramic phase is inferior to the solution of this application in terms of high-temperature resistance and other properties. Replacing the silicone resin of this application with phenolic resin results in insufficient high-temperature resistance. Direct curing of F5 may lead to an increase in the internal porosity of the resin or uneven local crosslinking density due to the violent evaporation of solvent or water, affecting the final mechanical properties.

[0070] In summary, the composite material obtained in this application exhibits minimal expansion and high mass retention under continuous use in ultra-high temperature environments, maintaining excellent mechanical properties after ultra-high temperature treatment and meeting the application requirements of composite materials at high temperatures. This application, through an acidic waterborne process, ultra-high temperature filler design, and pre-ceramization treatment, breaks through the temperature resistance limit of silicone-based resins while maintaining environmental friendliness, solving the failure problem of traditional materials in extreme environments.

[0071] The technical solution of this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention, including the best mode, and also to enable any person skilled in the art to practice this invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims. For those skilled in the art, it is understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this invention, and the scope of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an environmentally friendly modified ultra-high temperature resistant silicone resin material for prepreg, characterized by, The method comprises the following steps: (1) mixing phenyl silicone resin with silane coupling agent, and then adding emulsifier and stirring uniformly; (2) slowly adding deionized water under high-speed shearing to form a pre-emulsion, and then adding nano filler; (3) adjusting the pH of the system to 3.0±0.2 by using a pH regulator, and then adding high-temperature-resistant additive and silicon carbide whisker, and continuing to mix under high-speed shearing for 10-15 min; (4) vacuum degassing at-0.1 MPa for 30-40 min to obtain a semi-transparent to milky white water-based silicone resin material; The nano filler is added in an amount of 10%-20% of the mass of the phenyl silicone resin; The high-temperature-resistant additive is zinc borate, and the amount used is 5%-10% of the mass of the phenyl silicone resin; The amount of silicon carbide whisker used is 15%-25% of the mass of the phenyl silicone resin; In the step (2), the mass ratio of deionized water to phenyl silicone resin is 1:1; the nano filler is at least one sol of zirconium oxide, boron oxide or aluminum oxide; the nano filler has a particle size of 10-30 nm and a solid content of 20%; In the step (3), the pH regulator is a mixture of phosphoric acid and citric acid with a mass ratio of (1.5-2):1; the silicon carbide whisker is acidified by using 65% concentrated nitric acid for 2-3 h; the silicon carbide whisker has a diameter of 0.1-1 μm and a length-diameter ratio of ≥20.

2. The method of claim 1, wherein: In the step (1), the mass ratio of phenyl silicone resin to silane coupling agent is (9-10):1; the amount of emulsifier used is 3%-8% of the mass of the phenyl silicone resin; the emulsifier is dodecyl benzene sulfonic acid or phosphate ester.

3. The method of claim 1, wherein: In the step (4), the silicone resin material has a solid content of 50%±2% and a viscosity of 1000-2000 mPa·s; the high-speed shearing conditions in the steps (2) and (3) are 5000-8000 rpm.

4. A prepreg use environment-friendly modified ultra-high temperature resistant silicone resin material prepared by the preparation method in any one of claims 1-3.

5. A prepreg, characterized by: The prepreg use environment-friendly modified ultra-high temperature resistant silicone resin material comprises a mixed fabric substrate and a resin material, and the mixed fabric substrate is completely impregnated with the resin material; the mixed fabric is at least one of quartz fiber, silicon carbide fiber and alumina fiber; and the resin material is the prepreg use environment-friendly modified ultra-high temperature resistant silicone resin material in claim 4.

6. The method of making a prepreg according to claim 5, characterized in that, The method comprises the following steps: impregnating the mixed fabric in the resin material, coating the mixed fabric to a thickness of 0.1-0.4 mm and a resin content of 30%-40%, and then performing gradient drying to obtain a prepreg, wherein the volatile matter is ≤1%; and then the prepreg is heated to 120℃ at a rate of 5℃ / min and kept at 120℃ for 2 h, and then cooled to obtain the prepreg; The prepreg has a surface contact angle of ≥100° and a peel strength of 0.1-0.5 N / cm. The gradient drying specifically comprises the following steps: first drying at 60-65℃ for 10 min, and then drying at 95-100℃ for 20-25 min.

7. A composite material, characterized by: The composite material is obtained by curing the prepreg; the curing method comprises winding molding or mold pressing molding; and the prepreg is the prepreg in claim 5 or the prepreg obtained by the preparation method in claim 6.

8. The method of producing a composite material according to claim 7, characterized by, comprising the processes of: (i) providing a laminar stack of prepreg; (ii) heating the laminar stack of prepreg in an autoclave or compression mold to allow the resin material system to flow and fully impregnate the hybrid woven fabric substrate and form a cured resin matrix.

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