Environment-friendly modified ultra-high-temperature-resistant silicon resin material for prepreg, prepreg, composite material and preparation method of environment-friendly modified ultra-high-temperature-resistant silicon resin material

Abstract

The invention provides an environment-friendly modified ultra-high-temperature-resistant silicon resin material for a prepreg, the prepreg, a composite material and a preparation method of the environment-friendly modified ultra-high-temperature-resistant silicon resin material. The preparation method comprises the following steps: emulsifying phenyl silicone resin and a silane coupling agent, adding a nano filler and a high-temperature-resistant auxiliary agent, and carrying out pH regulation and vacuum defoaming to obtain high-stability water-based silicon-based resin; the preparation method comprises the following steps: dipping a fiber fabric, carrying out gradient drying, carrying out high-temperature treatment at 120 DEG C to form a prepreg, and carrying out lamination molding to obtain the composite material. The mass retention rate of the composite material in a 2000 DEG C argon environment is greater than or equal to 85%, and the ablation rate is less than or equal to 0.05 mm / s. The temperature resistance of the silicon-based resin is enhanced, the environmental protection property is excellent (VOC approaches to zero), and the silicon-based resin is suitable for extreme working condition scenes such as spacecraft thermal protection, nuclear reactor shielding and ultra-high temperature sensor packaging. The environment-friendly silicon resin system not only breaks through the temperature resistance limit of a traditional material, but also makes great progress in the aspects of environmental friendliness and cost effectiveness, and has remarkable technical breakthrough value and wide application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of resin-based thermal protection, and specifically relates to an environmentally friendly modified ultrahigh temperature resistant silicone resin material for prepreg, a prepreg, a composite material and a preparation method thereof. Background Art

[0002] With the rapid development of the aerospace and military industries, thermal protection materials are also facing harsh operating environments, such as high temperature, high pressure, and high heat flux. Because aerospace operates at high altitudes and high speeds, it requires that the external materials of the machine have excellent high temperature resistance, low temperature resistance, and ozone resistance. The development and demand of the aerospace industry have promoted the development of advanced composite materials, and the development and application of advanced composite materials have promoted the progress of aerospace. With the widespread use of advanced composite materials in the aerospace field, new requirements have been put forward for the performance of composite materials.

[0003] Fiber-reinforced silicone-based resin composites are widely used in heat-resistant components. Silicone resin is a highly branched organic silicon polymer with Si-O bonds as the main molecular chain. The Si-O bond improves the polymer's oxidative stability. Moreover, when the hydrocarbon group attached to the Si atom is oxidized by heat, it forms a more stable Si-O-Si bond, which prevents the main chain from breaking and degrading. Organic silicon polymers have excellent heat and weather resistance. They also have excellent flame retardancy, high insulation, and radiation protection properties, making them an indispensable and important supporting material for the aerospace industry. However, existing silicone resin prepregs have high viscosity and poor drapeability, which affects their practical application. Although traditional phenolic resin composites have a short-term temperature resistance of 1000°C and a long-term temperature resistance of 500°C, they can no longer meet the extreme performance requirements of modern scientific and technological development.

[0004] CN201610217852.5 discloses a silicone resin composition for prepregs, a carbon fiber prepreg, and a carbon fiber silicone resin composite material. The silicone resin composition for prepregs includes a silicone resin, a phenolic resin, a toughening agent, a functional filler, a coupling agent, and a catalyst. The carbon fiber prepreg includes a carbon fiber material and a silicone resin composition for prepregs. The carbon fiber silicone resin composite material is obtained by curing the carbon fiber prepreg; the curing method includes winding, casting, or compression molding. This patented carbon fiber prepreg is cured to produce a carbon fiber composite material having excellent mechanical properties and high-temperature resistance. The present invention is applicable to the field of silicone resin carbon fiber composite materials.

[0005] Patent CN 113637287A discloses a high-density premix of short-cut fibers / phenolic resin for aerospace ablation and heat protection, a manual premixing method, and a composite material. The premix is ​​prepared using a manual premixing process from high-temperature chopped fibers and high-residual carbon phenolic resin in the presence of additives. The premix is ​​then premixed through a series of processes, including yarn cutting, yarn drying, adhesive blending, manual premixing, loosening, laying, airing, drying, testing, packaging, storage, and commissioning. The result is an intermediate material with a certain degree of pre-curing, a loose state, and fibers with no defined orientation. The premix is ​​then molded in a sealed mold under a specific temperature and pressure to produce the aerospace ablation and heat protection composite material. Summary of the Invention

[0006] To address the problems of insufficient temperature resistance (<2000°C), high production costs, and environmental pollution in existing phenolic resin composites, the inventors of this application, building on their extensive research into resin-based thermal protection materials, have proposed an environmentally friendly modified ultra-high-temperature-resistant silicone resin material for prepregs, a prepreg, a composite material, and a preparation method thereof. This material utilizes an acidic water-based process combined with a ternary synergistic filler (silicon carbide whiskers, zinc borate, and a nano-inorganic material sol) to optimize the resin network structure. The preparation method includes emulsifying a phenyl silicone resin with a silane coupling agent, adding nanofillers and a high-temperature-resistant additive, adjusting the pH, and vacuum degassing to produce a highly stable water-based silicone resin. The fiber fabric is then impregnated and then gradient-dried. The pre-ceramic transition layer is formed by high-temperature treatment (120°C) in an inert atmosphere. The resulting laminate exhibits a mass retention rate of ≥85% and an ablation rate of ≤0.05 mm / s in an argon atmosphere at 2000°C. This invention boasts excellent environmental performance (VOC levels approaching zero) and is suitable for use in extreme operating conditions such as spacecraft thermal protection, nuclear reactor shielding, and ultra-high-temperature sensor packaging, enhancing the heat resistance of silicone-based resins. This environmentally friendly silicone resin system not only surpasses the temperature resistance limits of traditional materials but also achieves significant advances in environmental friendliness and cost-effectiveness, offering significant technological breakthroughs and broad application prospects.

[0007] A method for preparing an environmentally friendly modified ultrahigh temperature resistant silicone resin material for prepreg, comprising the following steps:

[0008] (1) Phenyl silicone resin and silane coupling agent are mixed, and then an emulsifier is added and stirred evenly; (2) Deionized water is slowly added under high-speed shearing to form a pre-emulsion, and then nanofillers are added; (3) The pH of the system is adjusted to 3.0±0.2 with a pH regulator, and a high-temperature resistant additive and silicon carbide whiskers are added, and the mixture is continued to be mixed under high-speed shearing for 10-15 minutes; (4) Vacuum degassing is performed under -0.1MPa conditions for 30-40 minutes to obtain a translucent to milky white water-based silicone resin material; Phenyl silicone resin has higher heat resistance than other resins. The introduction of phenyl groups can improve the rigidity and stability of the molecular chain, and can 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 the phenyl silicone resin.

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

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

[0014] In the above step (2), 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 particle size is 10-30 nm, and the solid content is 20%.

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

[0016] Silicon carbide whiskers are acidified with concentrated nitric acid (65%) for 2-3 hours; the silicon carbide whiskers have a diameter of 0.1-1μm and an aspect ratio of ≥20. This treatment requires concentrated nitric acid (65%) for 2 hours to enhance chemical bonding with the resin interface and improve the material's toughness. Silicon carbide whiskers possess high strength and high modulus, and when added to the resin, they act as a reinforcement, effectively improving the resin's mechanical properties, including tensile strength, flexural strength, and hardness, enabling it to withstand greater external forces and loads, expanding the resin's application range.

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

[0018] A prepreg comprises a hybrid fabric substrate and a resin material, wherein the hybrid fabric substrate is completely impregnated with the resin material; the hybrid fabric 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 prepreg obtained by the above preparation method.

[0019] The blended 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 ratio of 1:1:1;

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

[0022] Weaving: On a high-precision loom, we use twill weave 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-treatment: Blow dust removal, surface cleaning and high temperature heat treatment (200℃) to enhance the bonding strength between fibers and obtain a weight of 220g / m 2 , surface density about 220g / m 2 High-performance hybrid fabric with high temperature resistance and high strength.

[0024] The preparation method of the prepreg comprises the following steps: impregnating a mixed woven fabric in a resin material (impregnation conditions: room temperature, 10-20 minutes), with a coating thickness of 0.1-0.4 mm and a resin content of 30%-40%; then performing gradient drying to volatilize water and initially crosslink the resin, with the volatile matter being ≤1%; heating the prepreg to 120°C at a rate of 5°C / min, keeping the temperature for 2 hours, and cooling to obtain a prepreg (single-layer prepreg), wherein the obtained prepreg film surface is non-sticky, has a contact angle of ≥100°, but retains a slight stickiness (peel force of 0.1-0.5 N / cm); and the impregnation rate of the mixed woven fabric by the resin material in the prepreg is 98% or more.

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

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

[0027] The gradient drying process involves drying at 60-65°C for 10-15 minutes, followed by drying at 95-100°C for 20-25 minutes. The initial low temperature (e.g., 60°C) allows for the gradual evaporation of most of the free water, preventing microcracks caused by rapid shrinkage of the resin at high temperatures. The subsequent temperature increase to 100°C allows for further evaporation of any remaining water, promoting the initial cross-linking of the resin molecular chains and forming a more uniform network structure.

[0028] After heat treatment at 120°C, the prepreg becomes "non-sticky" while retaining slight stickiness between layers, facilitating the lamination of composite materials. The nanofillers are evenly dispersed to ensure a translucent state (transmittance 40%-60%, wavelength 600nm).

[0029] The above-mentioned prepreg layer can be cured to obtain a composite material; the above-mentioned curing method includes winding molding and compression molding.

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

[0031] a: Cut the prepreg into 20mm wide tapes using a cloth cutting machine;

[0032] b: Wrap the cut fabric tape onto a wrapping machine at 80-100 rpm, alternating spiral and hoop windings around a core mold. Keep the winding tension at 5-10 N. After wrapping, place the prepreg in an autoclave, heat it at 5°C / min to 600°C, hold it for 2 hours, and then cure it at 10 MPa for 2 hours. Demold it to obtain the composite product.

[0033] The specific molding preparation process is as follows:

[0034] c. Cut the prepreg into 300mm x 200mm cloth pieces using a cloth cutting machine, for a total of 20 prepreg pieces;

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

[0036] A method for preparing a composite material comprises the following steps: (i) providing a layered stack of prepregs; and (ii) heating the layered stack of prepregs in an autoclave or a molding die so that the resin material system flows and completely impregnates the hybrid fabric substrate to form a cured resin matrix.

[0037] The specific process of step (i) is to cut the prepreg into 300mm×200mm pieces and stack 20 pieces to make a prepreg stack (or cut the prepreg into the required size and lay the prepreg layer by layer to obtain a stack).

[0038] The SiC-B2O3-XO composite ceramic phase formed by heat treatment at 600°C after the resin is cured can withstand 2000°C thermal shock and maintain a mass retention rate of ≥85% in an argon environment at 2000°C.

[0039] Compared with the prior art, this application has the following advantages:

[0040] (1) The present application optimizes the resin network structure by combining an acidic aqueous process with a ternary synergistic filler (silicon carbide whiskers, zinc borate, and nano-inorganic material sol); the zinc borate and nano-inorganic material sol in the ternary synergistic filler cooperate with the silicon carbide whiskers to produce a synergistic effect; they can fill the gaps in the resin network, making the structure denser, further improving the mechanical properties and wear resistance of the resin, while enhancing the impact resistance of the resin, so that it can better absorb energy and reduce damage when subjected to external force. Silicon carbide whiskers and nano-inorganic material sol have good heat resistance and can improve the thermal stability of the resin, so that it can still maintain good performance in a high temperature environment and reduce the occurrence of thermal deformation and thermal decomposition. Zinc borate will decompose and absorb heat when heated, playing a role in flame retardancy and heat insulation, further improving the heat resistance of the resin, reducing the possibility of it burning at high temperatures, and improving safety in use.

[0041] (2) The addition of ternary synergistic fillers can reduce the thermal expansion coefficient of the resin, making the resin more stable in size 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 the present application has a non-sticky surface but slightly sticky properties, which facilitates lamination. The resulting laminate (composite material) has a mass retention rate of ≥85% and an ablation rate of ≤0.05 mm / s in an argon environment at 2000°C.

[0043] (4) This application has excellent environmental protection, and the VOC of the water-based system is close to zero (the acidic water-based process allows the resin to use water as a solvent, replacing traditional organic solvents. This greatly reduces the emission of volatile organic compounds (VOCs), reduces pollution to the atmospheric environment, and also improves the working environment during production and use, reducing harm to human health). Acidic conditions inhibit the growth of microorganisms and extend the storage period of the emulsion; 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-based resins. DETAILED DESCRIPTION

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] The preparation method of the environmentally friendly modified ultra-high temperature resistant silicone resin material for prepreg used in the following embodiments and comparative examples is prepared by the following steps: (1) mixing phenyl silicone resin with a silane coupling agent (methacryloxypropyltrimethoxysilane), and then adding an emulsifier (dodecylbenzenesulfonic acid) and stirring evenly; (2) slowly adding deionized water under high shear to form a pre-emulsion, and then adding nanofiller; (3) adjusting the pH of the system to 3.0±0.2 with a pH regulator, adding zinc borate and silicon carbide whiskers, and continuing to mix under high shear for 15 minutes; (4) vacuum degassing at -0.1 MPa for 35 minutes to obtain a translucent to milky white water-based 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 hours; the silicon carbide whiskers have a diameter of 0.5 μm and an aspect ratio of ≥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] After 6 months of storage, the viscosity change rate of the environmentally friendly modified ultra-high temperature resistant silicone resin material G1 used for prepreg is 3.5% (initial viscosity 1721mPa·s, 1773mPa·s after 6 months), which meets the design requirement of "viscosity change rate ≤ 5%".

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

[0053] The blended fabric substrate is obtained by the following method: quartz fiber, silicon carbide fiber, and alumina fiber are selected and mixed in a ratio of 1:1:1; the blended fiber is gently opened and combed, and then spun into a yarn with a linear density of 40 tex using a spinning machine to ensure fiber integrity and yarn strength; on a high-precision loom, it is woven using a twill weave with a warp density of 90 yarns / 10 cm and a weft density of 85 yarns / 10 cm to control tension and prevent fiber breakage; air blowing and dust removal are performed on the surface, and high-temperature heat treatment (200°C) is performed to improve the bonding strength between the fibers, resulting in a weight of 220 g / m 2 , surface density about 220g / m 2 High-performance blended fabric.

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

[0055] The mixed fabric is impregnated in a resin material (impregnation conditions are: room temperature, 10-20 minutes), with coating thickness and resin content of (H1, 0.1mm, 30%; H2, 0.2mm, 35%; H3, 0.4mm, 40%; H4, 0.2mm, 50%; H5 has the same thickness and resin content as H2, 0.2mm, 35%); then gradient drying is performed to volatilize moisture and initially cross-link the resin, with the volatile matter ≤1%; the prepreg is placed in an inert atmosphere furnace, heated to 120°C at 5°C / min, and kept warm for 2 hours to form a partially ceramic transition layer; after cooling, a single-layer prepreg is obtained, the surface of the obtained prepreg film is non-sticky, the contact angle is ≥100°, but it retains a slight stickiness (peel force 0.1-0.5N / cm); the impregnation rate of the above-mentioned resin material in the above-mentioned prepreg into the above-mentioned mixed fabric is above 98%.

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

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

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

[0059] c. Cut the single-layer prepreg into 300mm x 200mm cloth pieces using a cloth cutting machine, for a total of 20 prepreg pieces;

[0060] d: Place 20 pieces of cut prepreg fabrics into a molding die, heat to 600°C at 5°C / min, hold for 2 hours, and then cure at 10 MPa for 2 hours. After the resin is completely cured, demold the mold and cool to room temperature to obtain a composite molded product F.

[0061] The material number of the environmentally friendly modified ultra-high temperature resistant silicone resin used in the above composite materials and the specific conditions of 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 composite material F was subjected to performance testing using the test methods and standards referenced in GJB323A. The linear ablation rate was tested as follows: a sample measuring Φ50×15 mm was subjected to an oxyacetylene flame erosion test (oxygen flow rate 1142 L / h, acetylene flow rate 838 L / h), with the sample at a distance of 20 mm from the nozzle and an ablation time of 10 seconds. The 2000°C resistance test (mass retention rate in an argon atmosphere at 2000°C) was determined by DSC / TG testing. The flexural strength test was conducted using the standard GB / T6569-86 (flexural strength test after calcination at 2000°C for 10 minutes). 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 regulator, the system pH cannot be guaranteed to be stably maintained at around 3, which affects the resin hydrolysis crosslinking density and may increase the high-temperature cracking porosity, resulting in a certain degree of reduction in mechanical properties. Without the use of the ternary synergistic filler of the present application (silicon carbide whiskers, zinc borate, and nano-inorganic material sol), the resin network structure cannot be optimized, and the formed SiC-B2O3-XO composite ceramic phase is inferior to the present application in terms of high temperature resistance and other properties. The use of phenolic resin instead of the silicone resin of the present application has insufficient high temperature resistance. The one-time direct curing of F5 may increase the internal porosity of the resin or uneven local crosslinking density due to the violent volatilization of solvents 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 in high-temperature environments. Through an acidic water-based process combined with ultra-high temperature filler design and pre-ceramicization treatment, this application surpasses the temperature resistance limits of silicone-based resins while maintaining environmental protection, addressing the failure of traditional materials in extreme environments.

[0071] The above describes the technical solution of this application in detail. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is intended only to facilitate understanding of the method and core concepts of the present invention, including the best mode, and to enable anyone skilled in the art to practice the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention, and such improvements and modifications fall within the scope of protection of the claims. The scope of patent protection for the present invention is defined by the claims and may include other embodiments that may be conceived by those skilled in the art. If such other embodiments have structural elements that do not differ from the literal meaning of the claims, or if they include equivalent structural elements that do not differ substantially from the literal meaning of the claims, then such other embodiments are also intended to be included within the scope of the claims. It will be understood by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an environmentally friendly modified ultrahigh temperature resistant silicone resin material for prepreg, characterized in that: The method comprises the following steps: (1) mixing phenyl silicone resin and silane coupling agent, adding emulsifier and stirring evenly; (2) slowly adding deionized water under high-speed shearing to form a pre-emulsion, and then adding nanofiller; (3) adjusting the pH of the system to 3.0±0.2 with a pH regulator, adding a high-temperature resistant auxiliary agent and silicon carbide whiskers, and continuing to mix under high-speed shearing for 10-15 minutes; (4) vacuum degassing under -0.1MPa conditions for 30-40 minutes to obtain a translucent to milky white water-based silicone resin material; The amount of nanofiller added is 10%-20% of the mass of phenyl silicone resin; The high temperature resistant additive is zinc borate, and the dosage is 5%-10% of the mass of phenyl silicone resin; The amount of silicon carbide whiskers used is 15%-25% of the mass of the phenyl silicone resin.

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

3. The preparation method according to claim 1, wherein: In the step (2), 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 particle size of the nanofiller is 10-30 nm, and the solid content is 20%.

4. The preparation method according to claim 1, wherein: In the step (3), the pH regulator is a mixture of phosphoric acid and citric acid in a mass ratio of (1.5-2):1; the silicon carbide whiskers are acidified with concentrated nitric acid (65%) for 2-3 hours; the silicon carbide whiskers have a diameter of 0.1-1 μm and an aspect ratio of ≥20.

5. The preparation method according to claim 1, wherein: The solid content of the silicone resin material in step (4) is 50%±2% and the viscosity is 1000-2000mPa·s; the high-speed shearing condition in steps (2) and (3) is 5000-8000rpm.

6. The environmentally friendly modified ultrahigh temperature resistant silicone resin material for prepreg prepared by the preparation method according to any one of claims 1 to 5.

7. A prepreg, characterized in that: It comprises a blended fabric substrate and a resin material, wherein the blended fabric substrate is completely impregnated with the resin material; the blended fabric is at least one of quartz fiber, silicon carbide fiber, and alumina fiber; and the resin material is the environmentally friendly modified ultrahigh temperature resistant silicone resin material for prepregs as described in claim 6.

8. The method for preparing the prepreg according to claim 7, characterized in that: The method comprises the following steps: impregnating a mixed woven fabric in a resin material with a coating thickness of 0.1-0.4 mm and a resin content of 30%-40%; then performing gradient drying with a volatile matter of ≤1%; heating the prepreg at a rate of 5°C / min to 120°C, keeping the temperature for 2 hours, and cooling to obtain a prepreg; The obtained prepreg surface contact angle is ≥100° and the peeling force is 0.1-0.5N / cm; The gradient drying is specifically performed by first drying at 60-65° C. for 10 min and then drying at 95-100° C. for 20-25 min.

9. A composite material, characterized in that: The composite material is obtained by curing prepreg layers; the curing method includes winding molding or compression molding; the prepreg is the prepreg according to claim 7 or the prepreg obtained by the preparation method according to claim 8.

10. The method for preparing the composite material according to claim 9, characterized in that: The invention comprises the following processes: (i) providing a layered stack of prepregs; and (ii) heating the layered stack of prepregs in an autoclave or a molding die so that the resin material system flows and completely impregnates the hybrid fabric substrate and forms a cured resin matrix.

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