High-temperature-resistant anti-aging sealing gasket and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant anti-aging sealing gasket which is formed by pouring, curing and compounding polyimide / polysiloxane composite resin synergistically modified by adamantane derivatives and perfluorinated compounds and a non-metal net-shaped material, the polyimide / polysiloxane composite resin is composed of a component A, a component B and a component C. Under the action of the component C, the component A and the component B are mixed in a one-to-one mode to form the high-temperature-resistant anti-aging sealing gasket, and the high-temperature-resistant anti-aging sealing gasket is formed by compounding the polyimide / polysiloxane composite resin and the non-metal net-shaped material. The component A comprises aliphatic diamine, ethidene diamine, adamantane diamine and a first auxiliary agent, and the component B comprises a second auxiliary agent and a third auxiliary agent; the component B comprises aromatic dicarboxylic anhydride, perfluoro polycyclic siloxane, polymethyl polycyclic siloxane and a second auxiliary agent; and the component C is an alkaline solution. The sealing gasket disclosed by the invention not only has excellent high-temperature resistance and ageing resistance, but also shows excellent chemical corrosion resistance, radiation resistance and high-speed airflow impact resistance, and can meet the strict requirements of high-end industrial fields such as aerospace, chemical engineering and automobiles on high-performance sealing materials.

Description

Technical Field

[0001] The invention relates to the technical field of sealing gaskets, and in particular to a high temperature resistant and anti-aging sealing gasket and a preparation method thereof. Background Art

[0002] In the current industrial field, especially in the aerospace, chemical and automobile manufacturing industries, the performance requirements for sealing materials are becoming increasingly stringent. Traditional sealing gaskets often degrade in the face of extreme temperatures, chemical media, radiation environments and high-speed airflow impacts, resulting in unstable sealing performance, easy aging and shortened service life. For example, many sealing materials are prone to degradation or softening at high temperatures, and become fragile at low temperatures, affecting the sealing effect. In addition, the erosion of chemical media and long-term ultraviolet and cosmic ray radiation can also cause rapid attenuation of material properties. In the aerospace field, sealing gaskets also need to withstand the impact of high-speed airflow, which further aggravates the wear and degradation of materials. Therefore, the development of a sealing gasket that can adapt to extreme environmental conditions and has excellent high temperature resistance, aging resistance, chemical corrosion resistance and high-speed airflow impact resistance has become an important topic in the field of industrial sealing technology. Although there are many sealing materials on the market, most products still find it difficult to meet all of the above requirements, especially in terms of ensuring long-term stability and reliability. Therefore, researching and developing new high-performance sealing materials to adapt to more demanding application environments is a key direction for current technological development. Summary of the invention

[0003] In view of the above shortcomings of the prior art, the present invention provides a high temperature resistant and anti-aging sealing gasket to solve the technical problems of traditional sealing gaskets such as performance degradation, unstable sealing performance, easy aging and short service life under extreme temperature, chemical medium and radiation environment. By introducing adamantane derivatives and perfluorinated compounds to synergistically modify the polyimide / polysiloxane composite resin, and combining the reinforcing effect of non-metallic mesh materials, the sealing gasket of the present invention not only maintains excellent high temperature resistance and anti-aging performance, but also has excellent chemical corrosion resistance, radiation resistance and high-speed airflow impact resistance, which significantly improves the overall comprehensive performance and long-term durability of the sealing gasket, and meets the strict requirements for high-performance sealing materials in high-end industrial applications.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is: A high temperature resistant and anti-aging sealing gasket, the sealing gasket is formed by casting and curing a polyimide / polysiloxane composite resin modified by adamantane derivative and a perfluorinated compound and a non-metallic mesh material, the polyimide / polysiloxane composite resin is composed of component A, component B and component C, and the components A and B are gradually cured under the action of component C to obtain the polyimide / polysiloxane composite resin, wherein: The A component comprises the following raw materials and their weight proportions: 15-35 parts of aliphatic diamine 20-30 parts of ethylenediamine 10-15 parts of adamantane diamine The first auxiliary agent 0.1-2.5 parts The B component comprises the following raw materials and their weight proportions: 30-50 parts of aromatic dibasic acid anhydride 25-35 parts of perfluoropolycyclic siloxane 40-60 parts of polymethyl polycyclic siloxane 0.5 to 5 parts of the second auxiliary agent; The C component is an alkaline solution.

[0005] As a preferred technical solution, the aliphatic diamine is at least one of 1,6-hexanediamine, 1,7-heptanediamine or 1,8-octanediamine.

[0006] As a preferred technical solution, the adamantane diamine is at least one of 1,3-adamantane diamine, 4,4'-(adamantane-2,2-diyl) diphenylamine, 1,3-adamantane diethylamine and adamantane-1,3-dimethylamine.

[0007] As a preferred technical solution, the first auxiliary agent is at least one of an antioxidant, a stabilizer, and a wetting agent.

[0008] As a preferred technical solution, the aromatic dibasic acid anhydride is at least one of pyromellitic dianhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride.

[0009] As a preferred technical solution, the perfluoropolycyclic siloxane is prepared by addition reaction of perfluoropropylene and olefin polycyclic siloxane.

[0010] As a preferred technical solution, the olefin polycyclic siloxane is tetramethyltetravinylcyclotetrasiloxane and / or 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane.

[0011] As a preferred technical solution, the polymethyl polycyclic siloxane is at least one of dodecamethylcyclohexasiloxane, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane and hexamethylcyclotrisiloxane.

[0012] As a preferred technical solution, the second auxiliary agent is at least one of an antioxidant, a stabilizer, and a dispersant.

[0013] As a preferred technical solution, the non-metallic mesh material is at least one of a glass fiber mesh, a nylon mesh, and a polyester fiber mesh.

[0014] Another aspect of the present invention is to provide a method for preparing a high temperature resistant and anti-aging sealing gasket, the preparation method comprising the following steps: S1: The aliphatic diamine, ethylenediamine, adamantane diamine and the first auxiliary agent in component A are mixed uniformly according to a certain proportion; S2: The aromatic dibasic acid anhydride, perfluoropolycyclic siloxane, polymethylpolycyclic siloxane and the second auxiliary agent in component B are mixed uniformly according to a certain proportion; S3: The component A mixture obtained in step S1 and the component B mixture obtained in step S2 are stirred and mixed in proportion and then poured into a mold containing a non-metallic mesh material, and heated and pressurized to react in an inert atmosphere, and then component C is added and ultrasonically stirred to react, and then the temperature is gradually increased to react, and finally cured and formed to obtain the high temperature resistant and anti-aging sealing gasket.

[0015] The high temperature resistant and anti-aging sealing gasket of the present invention achieves excellent performance by adopting a composite structure of polyimide / polysiloxane composite resin and non-metallic mesh material. Polyimide / polysiloxane composite resin is used as the base material of the sealing gasket, which combines the high temperature resistance of polyimide and the low temperature resistance and flexibility of polysiloxane, providing excellent heat resistance and mechanical strength. The addition of non-metallic mesh materials, such as glass fiber mesh, nylon mesh, polyester fiber mesh, etc., further enhances the mechanical properties of the gasket, especially when subjected to pressure and vibration, providing additional stability and durability.

[0016] The synergistic modification of adamantane derivatives and perfluorinated compounds has brought significant technical effects to sealing gaskets. With its unique rigid structure, adamantane derivatives significantly improve the heat resistance and compression resistance of the material, allowing the gasket to maintain stable sealing performance in high temperature environments. The introduction of perfluorinated compounds provides the material with excellent chemical resistance and radiation resistance, especially in the face of high radiation environments such as nuclear radiation or cosmic rays, the gasket can maintain its physical and chemical properties unchanged, which is crucial for the normal operation of equipment in fields such as aerospace. The radiation resistance of adamantane derivatives is due to their special molecular structure and chemical properties. Their high-density and uniform electron cloud can absorb and scatter part of the radiation, reduce the penetration and damage of radiation to the inside of the material, and at the same time capture and quench the free radicals generated by radiation, reduce the chain reaction caused by free radicals, and protect the material from further oxidation and damage. In addition, the rigid structure of adamantane derivatives helps to maintain the shape and dimensional stability of the material in a radiation environment and reduce deformation and swelling caused by radiation. These characteristics make the sealing gasket of the present invention not only excellent in terms of high temperature resistance, aging resistance, chemical medium resistance, etc., but also able to maintain its performance without degradation in extreme environments such as radiation resistance and high-speed airflow resistance, demonstrating excellent technical effects. It is particularly suitable for high-end fields such as aerospace, and provides a long-term and stable sealing solution for equipment.

[0017] Beneficial effects of the present invention: The high temperature resistant and anti-aging sealing gasket of the present invention not only significantly improves the heat resistance and chemical resistance of the material, but also enhances its compression resistance and anti-aging performance by innovatively introducing adamantane derivatives and perfluorinated compounds into the polyimide / polysiloxane composite resin. This design not only enhances the stability of the gasket under extreme temperatures and chemical media, but also maintains its excellent mechanical strength and flexibility. In particular, in the face of extreme environments such as radiation resistance and high-speed airflow impact resistance, the gasket can maintain its physical and chemical properties unchanged, thereby achieving a long-term and reliable sealing effect.

[0018] In general, the high temperature resistant and aging resistant sealing gasket of the present invention not only has excellent temperature resistance and chemical resistance, but also has outstanding radiation resistance, high-speed airflow impact resistance and aging resistance, and can meet the strict requirements of high-end fields such as aerospace, petrochemical, and automobile manufacturing for high-performance sealing materials. DETAILED DESCRIPTION

[0019] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0020] Example 1

[0021] The high temperature resistant and anti-aging sealing gasket of this embodiment is formed by casting and curing a polyimide / polysiloxane composite resin modified by adamantane derivative and a perfluorinated compound and a non-metallic mesh material polyester fiber mesh (thickness 0.3 mm, pore size 1.5 mm), wherein the polyimide / polysiloxane composite resin is composed of component A, component B and component C, and the components A and B are gradually cured under the action of component C to obtain the polyimide / polysiloxane composite resin, wherein: The A component comprises the following raw materials and their weight proportions: 1,6-hexanediamine 15 parts 20 parts of ethylenediamine 1,3-adamantanediamine 10 parts Antioxidant (bis(2,4-di-tert-butylphenyl) phosphate) 0.5 parts Stabilizer (calcium stearate) 0.25 parts Wetting agent (polyoxyethylene sorbitan monolaurate) 0.25 parts; The B component comprises the following raw materials and their weight proportions: 30 parts of pyromellitic anhydride 25 parts of perfluoropolycyclic siloxane 40 parts of octamethylcyclotetrasiloxane Antioxidant (tris(2-chloropropyl) phosphate) 0.5 parts Stabilizer (rare earth lanthanum malate complex) 0.5 parts Organic silicone dispersant (Byk-310) 0.5 parts; The C component is a sodium hydroxide solution with a mass concentration of 30%.

[0022] The preparation method of the high temperature resistant and anti-aging sealing gasket of this embodiment comprises the following steps: S1: Mix 15 parts of 1,6-hexanediamine, 20 parts of ethylenediamine, 10 parts of 1,3-adamantanediamine, 0.5 parts of bis(2,4-di-tert-butylphenyl) phosphate, 0.25 parts of calcium stearate and 0.25 parts of polyoxyethylene sorbitan monolaurate in component A in proportion and mix them evenly. When mixing, ensure that all components are fully dispersed and evenly mixed. A mechanical stirrer can be used to stir at room temperature for 30 minutes; S2: Mix 30 parts of pyromellitic anhydride, 25 parts of perfluoropolycyclic siloxane, 40 parts of octamethylcyclotetrasiloxane, 0.5 parts of tris(2-chloropropyl) phosphate, 0.5 parts of rare earth lanthanum malate complex, and 0.5 parts of Byk-310 in component B in proportion and mix them evenly. In order to ensure that the dispersant Byk-310 can fully play its role, it should be mixed evenly with the resin before adding other additives, and stirred at room temperature for at least 15 minutes using a high-speed stirrer to form a premix, and then add other components and continue stirring for 30 minutes; S3: Stir and mix the component A mixture obtained in step S1 and the component B mixture obtained in step S2 in a mass ratio of 2:3, and pour them into a mold containing a non-metallic mesh material (polyester fiber mesh, thickness 0.3mm, pore size 1.5mm). Heat and increase the pressure to 60°C and 0.25MPa under an inert atmosphere (such as nitrogen protection) for 18 hours. Then add component C (sodium hydroxide solution) to make the pH value of the mixture reach 11, and carry out ultrasonic stirring reaction for 3 hours to promote the curing reaction. Gradually increase the temperature to 90°C and maintain for 4 hours, then increase the temperature to 210°C and maintain for another 2 hours to complete the curing reaction to obtain the high temperature resistant and anti-aging sealing gasket.

[0023] The perfluoropolycyclic siloxane is prepared by addition reaction of perfluoropropylene and tetramethyltetravinylcyclotetrasiloxane. Specifically, a certain amount of tetramethyltetravinylcyclotetrasiloxane is accurately measured and placed in a dry reaction bottle equipped with a stirrer. Then, an excess of perfluoropropylene gas is introduced into the reaction bottle to ensure that the perfluoropropylene remains in excess during the reaction. In a nitrogen atmosphere, a small amount of dibenzoyl peroxide (BPO) is added, the temperature is raised to 80°C, and the reaction is stirred for 6 hours to obtain the perfluoropolycyclic siloxane.

[0024] Example 2

[0025] The high temperature resistant and anti-aging sealing gasket of this embodiment is formed by casting and curing a polyimide / polysiloxane composite resin modified by adamantane derivative and a perfluorinated compound and a non-metallic mesh material polyester fiber mesh (thickness 0.3 mm, pore size 1.5 mm), wherein the polyimide / polysiloxane composite resin is composed of component A, component B and component C, and the components A and B are gradually cured under the action of component C to obtain the polyimide / polysiloxane composite resin, wherein: The A component comprises the following raw materials and their weight proportions: 30 parts of 1,7-heptanediamine 25 parts of ethylenediamine 1,3-adamantanediethylamine 12 parts Antioxidant (bis(2,4-di-tert-butylphenyl) phosphate) 1 part Stabilizer (calcium stearate) 0.5 parts Wetting agent (polyoxyethylene sorbitan monolaurate) 0.5 parts; The B component comprises the following raw materials and their weight proportions: 40 parts of 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride 30 parts of perfluoropolycyclic siloxane 50 parts of decamethylcyclopentasiloxane Antioxidant (Tris(2-chloropropyl) phosphate) 1 part Stabilizer (rare earth lanthanum malate complex) 0.5 parts Organic silicone dispersant (Byk-310) 1.5 parts; The C component is a sodium hydroxide solution with a mass concentration of 30%.

[0026] The preparation method of the high temperature resistant and anti-aging sealing gasket of this embodiment comprises the following steps: S1: Mix 30 parts of 1,7-heptanediamine, 25 parts of ethylenediamine, 12 parts of 1,3-adamantanediethylamine, 1 part of bis(2,4-di-tert-butylphenyl)phosphate, 0.5 parts of calcium stearate and 0.5 parts of polyoxyethylene sorbitan monolaurate in component A in proportion and mix them evenly. When mixing, ensure that all components are fully dispersed and evenly mixed. A mechanical stirrer can be used to stir at room temperature for 30 minutes; S2: Mix 40 parts of 2,3,3',4'-diphenyl ether tetracarboxylic anhydride, 30 parts of perfluoropolycyclic siloxane, 50 parts of decamethylcyclopentasiloxane, 1 part of tris(2-chloropropyl) phosphate, 0.5 parts of rare earth lanthanum malate complex, and 1.5 parts of Byk-310 in component B in proportion and mix them evenly. In order to ensure that the dispersant Byk-310 can fully play its role, it should be mixed evenly with the resin before adding other additives, and stirred at room temperature with a high-speed stirrer for at least 15 minutes to form a premix, and then add other components and continue stirring for 30 minutes; S3: Stir and mix the component A mixture obtained in step S1 and the component B mixture obtained in step S2 in a mass ratio of 2:3, and pour them into a mold containing a non-metallic mesh material (polyester fiber mesh, thickness 0.3mm, pore size 1.5mm). Heat and increase the pressure to 60°C and 0.25MPa under an inert atmosphere (such as nitrogen protection) for 18 hours. Then add component C (sodium hydroxide solution) to make the pH value of the mixture reach 11, and carry out ultrasonic stirring reaction for 3 hours to promote the curing reaction. Gradually increase the temperature to 90°C and maintain for 4 hours, then increase the temperature to 210°C and maintain for another 2 hours to complete the curing reaction to obtain the high temperature resistant and anti-aging sealing gasket.

[0027] The perfluoropolycyclic siloxane is the same as that in Example 1.

[0028] Example 3

[0029] The high temperature resistant and anti-aging sealing gasket of this embodiment is formed by casting and curing a polyimide / polysiloxane composite resin modified by adamantane derivative and a perfluorinated compound and a non-metallic mesh material polyester fiber mesh (thickness 0.3 mm, pore size 1.5 mm), wherein the polyimide / polysiloxane composite resin is composed of component A, component B and component C, and the components A and B are gradually cured under the action of component C to obtain the polyimide / polysiloxane composite resin, wherein: The A component comprises the following raw materials and their weight proportions: 35 parts of 1,8-octanediamine 30 parts of ethylenediamine 15 parts of 4,4'-(adamantane-2,2-diyl)diphenylamine Antioxidant (bis(2,4-di-tert-butylphenyl) phosphate) 1.5 parts Stabilizer (calcium stearate) 0.5 parts Wetting agent (polyoxyethylene sorbitan monolaurate) 0.5 parts; The B component comprises the following raw materials and their weight proportions: 2,3,3',4'-biphenyltetracarboxylic dianhydride 50 parts 35 parts of perfluoropolycyclic siloxane 60 parts of dodecamethylcyclohexasiloxane Antioxidant (Tris(2-chloropropyl) phosphate) 1.5 parts Stabilizer (rare earth lanthanum malate complex) 1.5 parts Organic silicone dispersant (Byk-310) 2 parts; The C component is a sodium hydroxide solution with a mass concentration of 30%.

[0030] The preparation method of the high temperature resistant and anti-aging sealing gasket of this embodiment comprises the following steps: S1: Mix 35 parts of 1,8-octanediamine, 30 parts of ethylenediamine, 15 parts of 4,4'-(adamantane-2,2-diyl)diphenylamine, 1.5 parts of bis(2,4-di-tert-butylphenyl)phosphate, 0.5 parts of calcium stearate and 0.5 parts of polyoxyethylene sorbitan monolaurate in component A in proportion and mix them evenly. When mixing, ensure that all components are fully dispersed and evenly mixed. A mechanical stirrer can be used to stir at room temperature for 30 minutes; S2: Mix 50 parts of 2,3,3',4'-biphenyltetracarboxylic anhydride, 35 parts of perfluoropolycyclic siloxane, 60 parts of dodecamethylcyclohexasiloxane, 1.5 parts of tris(2-chloropropyl) phosphate, 1.5 parts of rare earth lanthanum malate complex, and 2 parts of Byk-310 in component B in proportion and mix them evenly. In order to ensure that the dispersant Byk-310 can fully play its role, it should be mixed evenly with the resin before adding other additives, and stirred at room temperature with a high-speed stirrer for at least 15 minutes to form a premix, and then add other components and continue stirring for 30 minutes; S3: Stir and mix the component A mixture obtained in step S1 and the component B mixture obtained in step S2 in a mass ratio of 2:3, and pour them into a mold containing a non-metallic mesh material (polyester fiber mesh, thickness 0.3mm, pore size 1.5mm). Heat and increase the pressure to 60°C and 0.25MPa under an inert atmosphere (such as nitrogen protection) for 18 hours. Then add component C (sodium hydroxide solution) to make the pH value of the mixture reach 11, and carry out ultrasonic stirring reaction for 3 hours to promote the curing reaction. Gradually increase the temperature to 90°C and maintain for 4 hours, then increase the temperature to 210°C and maintain for another 2 hours to complete the curing reaction to obtain the high temperature resistant and anti-aging sealing gasket.

[0031] The perfluoropolycyclic siloxane is prepared by addition reaction of perfluoropropylene and 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane. The specific preparation method is the same as that in Example 1.

[0032] Example 4

[0033] The raw material composition and preparation steps of the high temperature resistant and anti-aging sealing gasket and the preparation method thereof of the present embodiment are basically the same as those of Example 1, except that, in the preparation method of the present embodiment, adamantane-1,3-dimethylamine is used instead of 1,3-adamantane diamine, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride is used instead of isophthalic acid dianhydride, and hexamethylcyclotrisiloxane is used instead of octamethylcyclotetrasiloxane.

[0034] Comparative Example 1 The raw material composition and preparation steps of the high temperature resistant and anti-aging sealing gasket and the preparation method thereof of this comparative example are basically the same as those of Example 1, except that, in the sealing gasket and the preparation method thereof of this comparative example, the component A does not contain 1,3-adamantanediamine.

[0035] Comparative Example 2 The raw material composition and preparation steps of the high temperature resistant and anti-aging sealing gasket and the preparation method thereof of this comparative example are basically the same as those of Example 1, except that, in the sealing gasket and the preparation method thereof of this comparative example, the component B does not contain perfluoropolycyclic siloxane.

[0036] The high temperature resistant and anti-aging sealing gaskets prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were subjected to performance tests, and the performance results are shown in Table 1: Among them, temperature resistance test: refer to standard ASTM D648, test the samples in a high temperature furnace or low temperature box, the temperature range is from -60℃ to 0℃, keep the temperature at a constant interval of 10℃ for 2 hours, from 100℃ to 400℃, keep the temperature at a constant interval of 20℃ for 2 hours, and determine the temperature resistance range by observing whether the material is deformed, cracked or has other performance changes under extreme temperatures.

[0037] Chemical corrosion resistance test: Referring to the standard ASTM G31, the samples are exposed to specific chemical media, respectively in sulfuric acid solution with a pH value of 1, sodium hydroxide solution with a pH value of 13, and ethanol organic solvent, each for 72 hours. After the samples are taken out, cleaned and dried, the appearance changes, weight loss or mechanical property changes of the samples are evaluated to assess the corrosion level of the chemical media on the material.

[0038] Radiation dose resistance test: With reference to the standard ISO 11343, the radiation dose resistance test of the sealing gasket samples will be carried out using a cobalt-60 gamma ray source. The test is carried out at room temperature, the sample size is 100mm×100mm, and at least 3 samples are used for each test. The samples will receive a radiation dose of up to 2000 to 6000Gy at a dose rate of 1Gy / min. After the irradiation is completed, the samples will be cooled and tested for their tensile strength and compression permanent deformation properties to evaluate the impact of radiation on material properties.

[0039] High-speed airflow impact resistance test: Refer to standard ASTM D3105, fix the sample in the wind tunnel test area, gradually increase the wind speed to the predetermined test speed, and keep the sample in the high-speed airflow for a certain period of time. Observe and record the impact resistance of the sample.

[0040] Anti-aging performance test: Referring to the standard ASTM G53, the samples are placed in an artificial accelerated aging test chamber to simulate environmental factors such as ultraviolet rays, temperature and humidity. The test conditions are set as follows: using UV-B lamps, with a wavelength of about 313nm and an irradiation intensity of 0.7W / m²; the temperature in the chamber is maintained at 85℃; and the humidity is controlled at 60%. The samples will be continuously exposed to this environment, and the samples will be taken out every 120 hours for performance testing, including tensile strength and compression permanent deformation performance, to evaluate the aging degree of the samples.

[0041] Hardness test: Refer to standard ASTM D2240 and use Shore durometer to measure the hardness of sealing gasket.

[0042] Tensile strength test: Refer to standard ISO 37, fix the sample on the fixture of the universal material testing machine, stretch the sample at a certain speed until it breaks. Record the maximum force and elongation at break at break, and calculate the tensile strength and elongation at break.

[0043] Compression set test: Referring to the standard ASTM D395, the sample is placed in a compression test device, and the compression force applied is 50% of the original thickness of the sample, and maintained for 70 hours. After the pressure is released, the permanent deformation of the sample is measured and the permanent deformation percentage is calculated.

[0044] Table 1 project Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Temperature range (℃) -50～320 -50～320 -50～320 -50～320 -40～300 -40～300 Chemical corrosion resistance (0-10 level) 9 8 9 8 8 7 Radiation tolerance (Gy) 5000 4800 5200 4900 3500 4200 High-speed airflow impact resistance (m / s) 300 280 320 310 310 250 Anti-aging performance, h 1200 1200 1200 1200 960 840 Hardness (Shore A) 90 88 92 89 87 84 Tensile strength (MPa) 25 24 26 25 22 21 Compression set (%) 5 6 4 5 10 10 The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A high temperature resistant and anti-aging sealing gasket, characterized in that: The sealing gasket is formed by casting and curing a polyimide / polysiloxane composite resin modified by adamantane derivative and a perfluorinated compound and a non-metallic mesh material. The polyimide / polysiloxane composite resin is composed of component A, component B and component C. Component A and component B are gradually cured under the action of component C to obtain the polyimide / polysiloxane composite resin, wherein: The A component comprises the following raw materials and their weight proportions: Aliphatic diamine 15-35 parts 20-30 parts of ethylenediamine 10-15 parts of adamantane diamine 0.1 to 2.5 parts of the first auxiliary agent; The B component comprises the following raw materials and their weight proportions: 30-50 parts of aromatic dibasic acid anhydride 25-35 parts of perfluoropolycyclic siloxane 40-60 parts of polymethyl polycyclic siloxane 0.5 to 5 parts of the second auxiliary agent; The C component is an alkaline solution.

2. The high temperature resistant and anti-aging sealing gasket according to claim 1, characterized in that: The aliphatic diamine is at least one of 1,6-hexanediamine, 1,7-heptanediamine or 1,8-octanediamine.

3. The high temperature resistant and anti-aging sealing gasket according to claim 1, characterized in that: The adamantane diamine is at least one of 1,3-adamantane diamine, 4,4'-(adamantane-2,2-diyl) diphenylamine, 1,3-adamantane diethylamine and adamantane-1,3-dimethylamine.

4. The high temperature resistant and anti-aging sealing gasket according to claim 1, characterized in that: The first auxiliary agent is at least one of an antioxidant, a stabilizer, and a wetting agent.

5. The high temperature resistant and anti-aging sealing gasket according to claim 1, characterized in that: The aromatic dibasic acid anhydride is at least one of pyromellitic dianhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride.

6. The high temperature resistant and anti-aging sealing gasket according to claim 1, characterized in that: The perfluoropolycyclic siloxane is prepared by addition reaction of perfluoropropylene and olefin polycyclic siloxane.

7. The high temperature resistant and anti-aging sealing gasket as claimed in claim 6, characterized in that: The olefin polycyclic siloxane is tetramethyltetravinylcyclotetrasiloxane and / or 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane.

8. The high temperature resistant and anti-aging sealing gasket according to claim 1, characterized in that: The polymethyl polycyclic siloxane is at least one of dodecamethylcyclohexasiloxane, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane and hexamethylcyclotrisiloxane.

9. The high temperature resistant and anti-aging sealing gasket according to claim 1, characterized in that: The second auxiliary agent is at least one of an antioxidant, a stabilizer, and a dispersant.

10. A method for preparing a high temperature resistant and anti-aging sealing gasket, characterized in that: The preparation method comprises the following steps: S1: The aliphatic diamine, ethylenediamine, adamantane diamine and the first auxiliary agent in component A are mixed uniformly according to a certain proportion; S2: The aromatic dibasic acid anhydride, perfluoropolycyclic siloxane, polymethylpolycyclic siloxane and the second auxiliary agent in component B are mixed uniformly according to a certain proportion; S3: The component A mixture obtained in step S1 and the component B mixture obtained in step S2 are stirred and mixed in proportion and then poured into a mold containing a non-metallic mesh material, and heated and pressurized to react in an inert atmosphere, and then component C is added and ultrasonically stirred to react, and then the temperature is gradually increased to react, and finally cured and formed to obtain the high temperature resistant and anti-aging sealing gasket.