Radiation-resistant sealing ring for nuclear power equipment and preparation method of radiation-resistant sealing ring

Abstract

The invention relates to the field of sealing rings, in particular to a radiation-resistant sealing ring for nuclear power equipment and a preparation method of the radiation-resistant sealing ring, and aims at solving the problems that an existing sealing ring is low in radiation resistance and low in elongation rate retention rate in a high-temperature environment. The perfluoroether raw rubber has the advantages of excellent physical and mechanical properties, heat resistance and radiation resistance, the radiation-resistant sealing ring for the nuclear power equipment is prepared by adding the modified boron nitride, the modified nano white carbon black and the modified fiber membrane for mixing, the heat resistance and the radiation resistance of the sealing ring are obviously improved, the reinforcing filler, the vulcanizing agent and the cross-linking agent are added for mixing, and the service life of the sealing ring is prolonged. The prepared radiation-resistant rubber material has excellent manufacturability, mechanical properties, radiation resistance, corrosion resistance and heat resistance.

Description

Technical Field

[0001] The present invention relates to the field of sealing rings, and in particular to a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof. Background Art

[0002] Nuclear chemical industry involves the entire cycle of nuclear energy development, utilization and treatment. For processes such as fuel reprocessing and radioactive waste disposal, the sealed transportation of radioactive waste is an inevitable link in the radioactive waste disposal process. The protective boundaries and sealing boundaries during the transportation process are important factors related to environmental and personnel safety. The sealing rings during the transportation of radioactive materials and the sealing performance level that the sealing rings can achieve are important indicators for evaluating whether the transportation of radioactive materials is safe and feasible.

[0003] However, when sealing rings are used in nuclear-related fields, they will face multiple risks of nuclear radiation such as gamma rays and neutrons. Long-term exposure to radiation environment will cause the performance of most sealing rings to degrade or even lose their functions. This will not only lead to waste of resources, but may also cause environmental pollution and serious safety accidents.

[0004] Therefore, it is of great significance to develop a radiation-resistant sealing ring and a preparation method thereof for use in nuclear power equipment. Summary of the Invention

[0005] In order to overcome the above-mentioned technical problems, the purpose of the present invention is to provide a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof. By mixing perfluoroether rubber, reinforcing filler, modified boron nitride, modified nano-silica, modified fiber membrane, vulcanizing agent and cross-linking agent and then vulcanizing, a radiation-resistant sealing ring for nuclear power equipment is obtained, which solves the problem that the existing sealing ring has low radiation resistance, resulting in performance degradation and loss of function.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing a radiation-resistant sealing ring for nuclear power equipment comprises the following steps: Step 1: Weigh 50 parts of perfluoroether rubber, 2 parts of vulcanizing agent, 1-2 parts of cross-linking agent, 5-8 parts of reinforcing filler, 3-5 parts of modified boron nitride, 5-8 parts of modified nano-silica, and 10 parts of modified fiber membrane, and set aside; Step 2: Add the perfluoroether rubber into an internal mixer, mix at 60°C for 3 minutes, add the reinforcing filler, modified boron nitride, and modified nano-silica, and continue mixing at 80°C for 8 minutes, add the modified fiber membrane, and mix at 70°C for 5 minutes to obtain a mixed rubber; Step 3: Put the mixed rubber into the open mill to make sheets, put it into the oven at 180℃ for 1h, add the vulcanizer and cross-linking agent and mix at 50℃ for 3min, stand for 24h after mixing, and then vulcanize. Put the mixed rubber into the sealing ring mold for one-stage vulcanization at 160℃ and 10MPa for 15min, and then carry out the second-stage vulcanization at 180℃ and 15MPa for 30min. After the second-stage vulcanization, carry out the third-stage vulcanization at 200℃ and 20MPa for 1h to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0007] As a preferred embodiment of the present invention, the perfluoroether rubber in step one is perfluoroether rubber PFR94; the vulcanizing agent is one of vulcanizing agent BIBP and vulcanizing agent bis 25; the cross-linking agent is cross-linking agent TAIC; and the reinforcing filler is carbon black N330.

[0008] As a preferred embodiment of the present invention, the modified boron nitride is prepared by the following steps: Step a1: urea, boric acid and glucose were added to an agate mortar and ground for 1-2 hours. The ground powder was placed in a tube furnace, nitrogen was introduced, and the mixture was heated to 900°C at a heating rate of 5°C / min and calcined for 5 hours. After the reaction, the mixture was cooled to 25°C. The reaction product was ground for 30 minutes and added to ultrapure water for ultrasonic dispersion for 20 minutes, followed by stirring for 30 minutes. The mixture was washed with hydrochloric acid solution for 1-2 times, and the washed product was placed in a vacuum oven at 60°C and dried for 24 hours to obtain carbon-doped boron nitride. Step a2: Add carbon-doped boron nitride, a coupling agent, and toluene to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube, and a constant pressure dropping funnel, mix, and perform ultrasonic treatment for 30 minutes. Then, introduce nitrogen protection, heat to 110°C, and continue stirring to react for 8 hours. After the reaction is completed, filter, wash the filter cake with ethanol 1-2 times, and then add it to a vacuum freeze dryer and freeze-dry at -50°C for 24-48 hours to obtain modified boron nitride.

[0009] As a preferred embodiment of the present invention: the usage ratio of the urea, boric acid and glucose in step a1 is 4.8g:0.2g:1g; and the mass fraction of the hydrochloric acid solution is 36-38%.

[0010] As a preferred embodiment of the present invention: the usage ratio of the carbon-doped boron nitride, coupling agent and toluene in step a2 is 1 g:0.125 g:200 mL: the coupling agent is silane coupling agent KH-550.

[0011] As a preferred embodiment of the present invention: the modified nano-silica is prepared by the following steps: Step b1: Sodium silicate, an active agent, anhydrous ethanol, and sodium bicarbonate were added to a three-necked flask equipped with a stirrer, a thermometer, and an air guide tube, and the mixture was stirred and modified at 55°C and 300 rpm for 1 hour. After the modification, deionized water was added and aged for 3 hours. The mixture was filtered using a vacuum pump, washed 2-3 times using a centrifuge, and then dried to obtain surfactant-coated nano-silica. Step b2: Add surfactant-coated nano-silica, anhydrous ethanol, and sodium bicarbonate to a reaction vessel, place it in a stirrer, and stir the reaction at 55°C and 375r / min for 1h. Then add silane coupling agent KH-550 to the reaction vessel, stir the reaction at 60-100°C and 300-375r / min for 1-3h. After the reaction stops, pour it into a beaker, add deionized water, and age it for 3h. Finally, use a vacuum pump to filter, wash it 3 times with a centrifuge, and then dry it to obtain modified nano-silica.

[0012] As a preferred embodiment of the present invention: the usage ratio of the sodium silicate, active agent, anhydrous ethanol and sodium bicarbonate in step b1 is 1-5g:0.1-0.5g:20-30mL:23-26g; the active agent is one of cetyltrimethylammonium bromide, polyethylene glycol PEG6000 and sodium dodecylbenzenesulfonate.

[0013] As a preferred embodiment of the present invention: the usage ratio of the surfactant-coated nano-silica, anhydrous ethanol, sodium bicarbonate and silane coupling agent KH-550 in step b2 is 10-20g:20-25mL:23-26g:1-10g.

[0014] As a preferred embodiment of the present invention: the modified fiber membrane is prepared by the following steps: Step c1: adding bismuth oxide particles with an average particle size of 50 nm to N,N-dimethylformamide, ultrasonically dispersing for 2 hours and then stirring for 4 hours, adding polyurethane to the above solution, stirring at 25°C for 12 hours, adding the solution to an electrospinning apparatus using glossy paper as a receiving substrate for spinning, and then drying in a vacuum oven at 80°C for 2 hours to obtain a bismuth oxide nanofiber membrane; Step c2: Heat and dry the gadolinium oxide nanosheets in a vacuum oven, add them to deionized water, and stir for 1 hour to obtain an aqueous dispersion of gadolinium oxide, add a binder to the above-mentioned aqueous dispersion of gadolinium oxide to obtain an impregnation solution, cut the bismuth oxide nanofiber membrane into 2×2 cm squares, and stack them layer by layer, place the stacked fiber membranes into the impregnation solution, soak for 2 hours, and freeze them in liquid nitrogen to obtain fiber membrane frozen blocks, then place the fiber membrane frozen blocks in a freeze dryer and vacuum freeze-dry for 24 hours, and then heat them at 120°C for 2 hours to obtain a cross-linked modified fiber membrane.

[0015] As a preferred embodiment of the present invention: the usage ratio of the bismuth oxide particles, N,N-dimethylformamide and polyurethane in step c1 is 2-5 g:20-50 mL:1-5 g: the polyurethane is polyurethane WHT-3395.

[0016] As a preferred embodiment of the present invention: the usage ratio of the gadolinium oxide nanosheets, deionized water, adhesive and bismuth oxide nanofiber membrane in step c2 is 1-5g:50-100mL:1-3g:1-5g; the adhesive is hexamethylene diisocyanate.

[0017] Beneficial effects of the present invention: The present invention discloses a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof. The preparation method comprises the following steps: adding perfluoroether rubber, a reinforcing filler, modified boron nitride, and modified nano-silica into an internal mixer for internal mixing, adding a modified fiber membrane for mixing, and obtaining a rubber mixture; placing the rubber mixture into an open mixer for sheeting, adding a vulcanizing agent and a cross-linking agent for mixing, and placing the rubber mixture into a sealing ring mold for three-stage vulcanization after the mixing is completed, thereby obtaining a radiation-resistant sealing ring for nuclear power equipment. The preparation method uses perfluoroether rubber as a main raw material. The perfluoroether rubber has the advantages of excellent physical and mechanical properties, heat resistance, radiation resistance, electrical insulation, flame retardancy, and vacuum resistance. By adding modified boron nitride and modified nano-silica into the perfluoroether rubber, the heat resistance and radiation resistance of the rubber prepared from the perfluoroether rubber can be significantly improved. The reinforcing filler, the vulcanizing agent, and the cross-linking agent are added into the rubber mixture for mixing and preparing the radiation-resistant rubber, so that the prepared radiation-resistant rubber material has excellent processability, mechanical properties, radiation resistance, corrosion resistance, and heat resistance.

[0018] In the process of preparing radiation-resistant sealing rings for nuclear power equipment, a modified boron nitride is first prepared. Urea, boric acid and glucose are mixed and ground, calcined, and then ground again. The mixture is added to ultrapure water for ultrasonic dispersion, stirring, washing and drying. The mixture is mixed with silane coupling agent KH-550 and toluene, and ultrasonic treatment, stirring reaction, filtration, washing and freeze-drying are performed to obtain modified boron nitride. Boron nitride has excellent wear resistance, high temperature resistance and corrosion resistance. Carbon-doped boron nitride is obtained by calcining it with glucose, and carbon atoms are embedded in the plane of boron nitride to reduce Its interfacial thermal resistance enhances the thermal conductivity within the interface. Carbon can stabilize the boron-10 enriched structure. Carbon doping can promote the segregation of boron-10 between carbon nitride nanosheets, improve the neutron absorption efficiency per unit volume, and reduce the high-temperature volatilization of boron-10. The surface of carbon-doped boron nitride is modified with silane coupling agent KH-550. The silane coupling agent KH-550 can form hydrogen bonds between the inorganic filler and the silicone rubber matrix through amino groups and silanol groups formed by hydrolysis, thereby improving the compatibility between the inorganic filler and the matrix and improving the mechanical properties of the polymer matrix.

[0019] In the process of preparing radiation-resistant sealing rings for nuclear power equipment, a modified nano-silica is first prepared. Sodium silicate, an active agent, anhydrous ethanol and sodium bicarbonate are mixed and stirred for modification, and then aged, filtered and dried to obtain surfactant-coated nano-silica; the surfactant-coated nano-silica, anhydrous ethanol and sodium bicarbonate are added to a reaction vessel and stirred for reaction, and then a coupling agent is added and mixed and stirred for reaction. After the reaction stops, the modified nano-silica is obtained after aging, filtering, washing and drying; nano-silica is generated by neutralizing sodium silicate and sodium bicarbonate. Nano-silica has a high absorption rate for ultraviolet and visible light reflection, and the advantage of a large specific surface area can greatly reduce the impurity concentration at the interface. , thus improving the mechanical properties of the material, and then the active agent is coated and modified on the nano-silica, and the cationic matrix on its surface is electrostatically attracted to the silicon hydroxyl groups on the surface of the silicon hydroxyl group, and the long alkyl chain of the surfactant can form a spatial steric layer, thereby improving the dispersion stability, reducing the aggregation of fillers, and improving the uniformity of reinforcement. The coating of the surfactant can increase the tentacles of the silicon hydroxyl group and reduce the risk of water molecule penetration in a high-humidity environment; and then the surface is modified by a coupling agent. The coupling agent is hydrolyzed to generate silicon hydroxyl groups, which react with the surface hydroxyl groups of the nano-silica to remove a molecule of water and graft long-chain organic groups on its surface to enhance the hydrophobicity, improve the dispersibility of the nano-silica in organic solvents, and enhance its compatibility with the organic matrix.

[0020] In the process of preparing radiation-resistant sealing rings for nuclear power equipment, a modified fiber membrane is first prepared. Bismuth oxide particles and polyurethane are added to an N,N-dimethylformamide solution, ultrasonically dispersed, stirred, spun, and dried to obtain a bismuth oxide nanofiber membrane. Gadolinium oxide nanosheets are heated and dried, added to deionized water and stirred, and a binder is added. The bismuth oxide nanofiber membrane is cut and stacked layer by layer for impregnation, freeze-vacuum freeze-drying, and then heated to obtain a cross-linked modified fiber membrane. Bismuth oxide has a high atomic number, thermal stability, biocompatibility, and low toxicity. Its high atomic number gives it strong photoelectric effect and Compton scattering ability. Gadolinium oxide has a high thermal neutron absorption cross-section. By capturing neutrons, the two synergistically provide efficient radiation shielding efficiency. The online micro-interlocking and in-situ nanoparticle fusion between the bismuth oxide and gadolinium oxide fibers significantly improve the adhesion strength of the bismuth oxide / gadolinium oxide interface in the fiber membrane, which has efficient ionizing radiation absorption capacity. The periodic lattice of the bismuth oxide and gadolinium oxide crystals also facilitates multiple short-range internal reflections of X-rays, resulting in ultra-high X-ray attenuation efficiency. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] Example 1: This example is a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof, comprising the following steps: Step s1: 4.8 g of urea, 0.2 g of boric acid, and 1 g of glucose were added to an agate mortar and ground for 1 h. The ground powder was placed in a tube furnace, protected by nitrogen, and heated to 900 ° C at a heating rate of 5 ° C / min, and the calcination reaction was continued for 5 h. After the reaction was completed, it was cooled to 25 ° C. The reaction product was ground for 30 min and added to ultrapure water. Ultrasonic dispersion was performed for 20 min, and then stirred for 30 min. The product was washed with a hydrochloric acid solution with a mass fraction of 36%. The washed product was placed in a vacuum oven at 60 ° C and dried for 24 h to obtain carbon-doped boron nitride; Step s2: 1 g of carbon-doped boron nitride, 0.125 g of silane coupling agent KH-550, and 200 mL of toluene were added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube, and a constant pressure dropping funnel, mixed, and ultrasonically treated for 30 minutes. Nitrogen protection was introduced, and the mixture was heated to 110° C. and stirred for 8 hours. After the reaction was completed, the mixture was filtered, and the filter cake was washed with ethanol. It was then added to a vacuum freeze dryer and freeze-dried at -50° C. for 24 hours to obtain modified boron nitride; Step s3: 1 g of sodium silicate, 0.1 g of hexadecyltrimethylammonium bromide, 20 mL of anhydrous ethanol, and 23 g of sodium bicarbonate were added to a three-necked flask equipped with a stirrer, a thermometer, and an air guide tube. The mixture was stirred and modified at 55° C. and 300 rpm for 1 h. After the modification, deionized water was added and aged for 3 h. The mixture was filtered using a vacuum pump, washed twice using a centrifuge, and then dried to obtain surfactant-coated nano-silica. Step s4: 10 g of surfactant-coated nano-silica, 20 mL of anhydrous ethanol, and 23 g of sodium bicarbonate were added to a reaction vessel, placed in a stirrer, and stirred at 55° C. and 375 r / min for 1 h. Then, 1 g of silane coupling agent KH-550 was added to the reaction vessel, and stirred at 60° C. and 300 r / min for 1-3 h. After the reaction stopped, the mixture was poured into a beaker, deionized water was added, and aged for 3 h. Finally, the mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain modified nano-silica; Step s5: 2 g of bismuth oxide particles with an average particle size of 50 nm were added to 20 mL of N,N-dimethylformamide, ultrasonically dispersed for 2 h, and then stirred for 4 h. 1 g of polyurethane WHT-3395 was added to the above solution, stirred at 25°C for 12 h, and added to an electrospinning apparatus using glossy paper as a receiving substrate for spinning. The mixture was then dried in a vacuum oven at 80°C for 2 h to obtain a bismuth oxide nanofiber membrane. Step s6: 1 g of gadolinium oxide nanosheets were heated and dried in a vacuum oven, added to 50 mL of deionized water, and stirred for 1 hour to obtain an aqueous dispersion of gadolinium oxide, 1 g of hexamethylene diisocyanate was added to the aqueous dispersion of gadolinium oxide to obtain an impregnation solution, 1 g of bismuth oxide nanofiber membranes were cut into 2×2 cm squares and stacked layer by layer, the stacked fiber membranes were placed in the impregnation solution, immersed for 2 hours, and frozen in liquid nitrogen to obtain a fiber membrane frozen block, and then the fiber membrane frozen block was placed in a freeze dryer for vacuum freeze drying for 24 hours, and then heated at 120° C. for 2 hours to obtain a cross-linked modified fiber membrane; Step s7: Weigh 50 parts of perfluoroether rubber PFR94, 2 parts of vulcanizing agent BIBP, 1 part of crosslinking agent TAIC, 5 parts of carbon black N330, 3 parts of modified boron nitride, 5 parts of modified nano-silica, and 10 parts of modified fiber membrane and set aside; Step s8: adding perfluoroether rubber PFR94 to an internal mixer and mixing at 60°C for 3 minutes, adding carbon black N330, modified boron nitride, and modified nano-silica and mixing at 80°C for another 8 minutes, adding the modified fiber membrane and mixing at 70°C for 5 minutes to obtain a mixed rubber; Step s9: Place the rubber mixture into an open mixer to form sheets, place it in an oven and treat it at 180℃ for 1h, add vulcanizing agent BIBP and cross-linking agent TAIC and mix them at 50℃ for 3min, stand for 24h after mixing and then vulcanize, place the rubber mixture into a sealing ring mold for one-stage vulcanization at 160℃ and 10MPa for 15min, and then carry out two-stage vulcanization at 180℃ and 15MPa for 30min, and then carry out three-stage vulcanization at 200℃ and 20MPa for 1h to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0023] Example 2: This example is a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof, comprising the following steps: Step s1: 4.8 g of urea, 0.2 g of boric acid, and 1 g of glucose were added to an agate mortar and ground for 1.5 h. The ground powder was placed in a tube furnace, nitrogen was introduced, and the mixture was heated to 900 ° C at a heating rate of 5 ° C / min, and the calcination reaction was continued for 5 h. After the reaction was completed, the mixture was cooled to 25 ° C. The reaction product was ground for 30 min and added to ultrapure water. Ultrasonic dispersion was performed for 20 min, and then stirred for 30 min. The mixture was washed twice with a 37% hydrochloric acid solution by mass. The washed product was placed in a vacuum oven at 60 ° C and dried for 24 h to obtain carbon-doped boron nitride; Step s2: 1 g of carbon-doped boron nitride, 0.125 g of silane coupling agent KH-550, and 200 mL of toluene were added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube, and a constant pressure dropping funnel, mixed, and ultrasonically treated for 30 minutes. Nitrogen protection was introduced, heated to 110° C., and stirred for 8 hours. After the reaction was completed, the mixture was filtered, and the filter cake was washed twice with ethanol. It was then added to a vacuum freeze dryer and freeze-dried at -50° C. for 36 hours to obtain modified boron nitride; Step s3: 3 g of sodium silicate, 0.3 g of hexadecyltrimethylammonium bromide, 25 mL of anhydrous ethanol, and 25 g of sodium bicarbonate were added to a three-necked flask equipped with a stirrer, a thermometer, and an air guide tube. The mixture was stirred and modified at 55° C. and 300 rpm for 1 h. After the modification, deionized water was added and aged for 3 h. The mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain surfactant-coated nano-silica. Step s4: 15 g of surfactant-coated nano-silica, 23 mL of anhydrous ethanol, and 25 g of sodium bicarbonate were added to a reaction vessel, placed in a stirrer, and stirred at 55° C. and 375 r / min for 1 h. Then, 5 g of silane coupling agent KH-550 was added to the reaction vessel, stirred at 80° C. and 350 r / min for 2 h. After the reaction stopped, the mixture was poured into a beaker, deionized water was added, and aged for 3 h. Finally, the mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain modified nano-silica; Step s5: 4 g of bismuth oxide particles with an average particle size of 50 nm were added to 35 mL of N,N-dimethylformamide, ultrasonically dispersed for 2 h, and then stirred for 4 h. 3 g of polyurethane WHT-3395 was added to the above solution, stirred at 25°C for 12 h, and added to an electrospinning apparatus using glossy paper as a receiving substrate for spinning. The mixture was then dried in a vacuum oven at 80°C for 2 h to obtain a bismuth oxide nanofiber membrane. Step s6: 3 g of gadolinium oxide nanosheets were heated and dried in a vacuum oven, added to 75 mL of deionized water, and stirred for 1 hour to obtain an aqueous dispersion of gadolinium oxide, 2 g of hexamethylene diisocyanate was added to the aqueous dispersion of gadolinium oxide to obtain an impregnation solution, 3 g of bismuth oxide nanofiber membranes were cut into 2×2 cm squares and stacked layer by layer, the stacked fiber membranes were placed in the impregnation solution, immersed for 2 hours, and frozen in liquid nitrogen to obtain a fiber membrane frozen block, and then the fiber membrane frozen block was placed in a freeze dryer for vacuum freeze drying for 24 hours, and then heated at 120° C. for 2 hours to obtain a cross-linked modified fiber membrane; Step s7: Weigh 50 parts of perfluoroether rubber PFR94, 2 parts of vulcanizing agent BIBP, 2 parts of crosslinking agent TAIC, 7 parts of carbon black N330, 4 parts of modified boron nitride, 7 parts of modified nano-silica, and 10 parts of modified fiber membrane and set aside; Step s8: adding perfluoroether rubber PFR94 to an internal mixer and mixing at 60°C for 3 minutes, adding carbon black N330, modified boron nitride, and modified nano-silica and mixing at 80°C for another 8 minutes, adding the modified fiber membrane and mixing at 70°C for 5 minutes to obtain a mixed rubber; Step s9: Place the rubber mixture into an open mixer to form sheets, place it in an oven and treat it at 180℃ for 1h, add vulcanizing agent BIBP and cross-linking agent TAIC and mix them at 50℃ for 3min, stand for 24h after mixing and then vulcanize, place the rubber mixture into a sealing ring mold for one-stage vulcanization at 160℃ and 10MPa for 15min, and then carry out two-stage vulcanization at 180℃ and 15MPa for 30min, and then carry out three-stage vulcanization at 200℃ and 20MPa for 1h to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0024] Example 3: This example is a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof, comprising the following steps: Step s1: 4.8 g of urea, 0.2 g of boric acid, and 1 g of glucose were added to an agate mortar and ground for 2 h. The ground powder was placed in a tube furnace, nitrogen was introduced, and the mixture was heated to 900 ° C at a heating rate of 5 ° C / min, and the calcination reaction was continued for 5 h. After the reaction was completed, the mixture was cooled to 25 ° C. The reaction product was ground for 30 min and added to ultrapure water. Ultrasonic dispersion was performed for 20 min, and then stirred for 30 min. The mixture was washed twice with a 38% mass fraction hydrochloric acid solution. The washed product was placed in a vacuum oven at 60 ° C and dried for 24 h to obtain carbon-doped boron nitride; Step s2: 1 g of carbon-doped boron nitride, 0.125 g of silane coupling agent KH-550, and 200 mL of toluene were added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube, and a constant pressure dropping funnel, mixed, and ultrasonically treated for 30 min. Nitrogen protection was introduced, heated to 110° C., and stirred for 8 h. After the reaction was completed, the mixture was filtered, and the filter cake was washed twice with ethanol. It was then added to a vacuum freeze dryer and freeze-dried at -50° C. for 48 h to obtain modified boron nitride; Step s3: 5 g of sodium silicate, 0.5 g of hexadecyltrimethylammonium bromide, 30 mL of anhydrous ethanol, and 26 g of sodium bicarbonate were added to a three-necked flask equipped with a stirrer, a thermometer, and an air guide tube. The mixture was stirred and modified at 55° C. and 300 rpm for 1 h. After the modification, deionized water was added and aged for 3 h. The mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain surfactant-coated nano-silica. Step s4: 20 g of surfactant-coated nano-silica, 25 mL of anhydrous ethanol, and 26 g of sodium bicarbonate were added to a reaction vessel, placed in a stirrer, and stirred at 55° C. and 375 r / min for 1 h. Then, 10 g of silane coupling agent KH-550 was added to the reaction vessel, and stirred at 100° C. and 375 r / min for 3 h. After the reaction stopped, the mixture was poured into a beaker, deionized water was added, and aged for 3 h. Finally, a vacuum pump was used for filtration, and the mixture was washed three times with a centrifuge and then dried to obtain modified nano-silica; Step s5: 5 g of bismuth oxide particles with an average particle size of 50 nm were added to 50 mL of N,N-dimethylformamide, ultrasonically dispersed for 2 h, and then stirred for 4 h. 5 g of polyurethane WHT-3395 was added to the above solution, stirred at 25°C for 12 h, and added to an electrospinning device using glossy paper as a receiving substrate for spinning. The mixture was then dried in a vacuum oven at 80°C for 2 h to obtain a bismuth oxide nanofiber membrane. Step s6: 5 g of gadolinium oxide nanosheets were heated and dried in a vacuum oven, added to 100 mL of deionized water, and stirred for 1 hour to obtain an aqueous dispersion of gadolinium oxide, 3 g of hexamethylene diisocyanate was added to the aqueous dispersion of gadolinium oxide to obtain an impregnation solution, 5 g of bismuth oxide nanofiber membranes were cut into 2×2 cm squares and stacked layer by layer, the stacked fiber membranes were placed in the impregnation solution, immersed for 2 hours, and frozen in liquid nitrogen to obtain a fiber membrane frozen block, and then the fiber membrane frozen block was placed in a freeze dryer for vacuum freeze drying for 24 hours, and then heated at 120° C. for 2 hours to obtain a cross-linked modified fiber membrane; Step s7: Weigh 50 parts of perfluoroether rubber PFR94, 2 parts of vulcanizing agent BIBP, 2 parts of crosslinking agent TAIC, 8 parts of carbon black N330, 5 parts of modified boron nitride, 8 parts of modified nano-silica, and 10 parts of modified fiber membrane and set aside; Step s8: adding perfluoroether rubber PFR94 to an internal mixer and mixing at 60°C for 3 minutes, adding carbon black N330, modified boron nitride, and modified nano-silica and mixing at 80°C for another 8 minutes, adding the modified fiber membrane and mixing at 70°C for 5 minutes to obtain a mixed rubber; Step s9: Place the rubber mixture into an open mixer to form sheets, place it in an oven and treat it at 180℃ for 1h, add vulcanizing agent BIBP and cross-linking agent TAIC and mix them at 50℃ for 3min, stand for 24h after mixing and then vulcanize, place the rubber mixture into a sealing ring mold for one-stage vulcanization at 160℃ and 10MPa for 15min, and then carry out two-stage vulcanization at 180℃ and 15MPa for 30min, and then carry out three-stage vulcanization at 200℃ and 20MPa for 1h to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0025] Comparative Example 1: This comparative example is a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof, comprising the following steps: Step s1: weigh 50 parts of perfluoroether rubber PFR94, 2 parts of vulcanizing agent BIBP, 2 parts of cross-linking agent TAIC, and 7 parts of carbon black N330, and set aside; Step s2: adding perfluoroether rubber PFR94 into an internal mixer, mixing at 60°C for 3 minutes, adding carbon black N330, and further mixing at 80°C for 8 minutes to obtain a rubber mixture; Step s3: Place the rubber mixture into an open mill to form a sheet, place it in an oven at 180°C for 1 hour, add the vulcanizing agent BIBP and the cross-linking agent TAIC and mix them at 50°C for 3 minutes, stand for 24 hours after mixing, and then vulcanize it. Place the rubber mixture into a sealing ring mold for one-stage vulcanization at 160°C and 10MPa for 15 minutes, and then carry out the second-stage vulcanization at 180°C and 15MPa for 30 minutes. After the second-stage vulcanization, carry out the third-stage vulcanization at 200°C and 20MPa for 1 hour to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0026] Comparative Example 2: This comparative example is a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof, comprising the following steps: Step s1: 4.8 g of urea, 0.2 g of boric acid, and 1 g of glucose were added to an agate mortar and ground for 1.5 h. The ground powder was placed in a tube furnace, nitrogen was introduced, and the mixture was heated to 900 ° C at a heating rate of 5 ° C / min, and the calcination reaction was continued for 5 h. After the reaction was completed, the mixture was cooled to 25 ° C. The reaction product was ground for 30 min and added to ultrapure water. Ultrasonic dispersion was performed for 20 min, and then stirred for 30 min. The mixture was washed twice with a 37% hydrochloric acid solution by mass. The washed product was placed in a vacuum oven at 60 ° C and dried for 24 h to obtain carbon-doped boron nitride; Step s2: 1 g of carbon-doped boron nitride, 0.125 g of silane coupling agent KH-550, and 200 mL of toluene were added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube, and a constant pressure dropping funnel, mixed, and ultrasonically treated for 30 minutes. Nitrogen protection was introduced, heated to 110° C., and stirred for 8 hours. After the reaction was completed, the mixture was filtered, and the filter cake was washed twice with ethanol. It was then added to a vacuum freeze dryer and freeze-dried at -50° C. for 36 hours to obtain modified boron nitride; Step s3: 3 g of sodium silicate, 0.3 g of hexadecyltrimethylammonium bromide, 25 mL of anhydrous ethanol, and 25 g of sodium bicarbonate were added to a three-necked flask equipped with a stirrer, a thermometer, and an air guide tube. The mixture was stirred and modified at 55° C. and 300 rpm for 1 h. After the modification, deionized water was added and aged for 3 h. The mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain surfactant-coated nano-silica. Step s4: 15 g of surfactant-coated nano-silica, 23 mL of anhydrous ethanol, and 25 g of sodium bicarbonate were added to a reaction vessel, placed in a stirrer, and stirred at 55° C. and 375 r / min for 1 h. Then, 5 g of silane coupling agent KH-550 was added to the reaction vessel, stirred at 80° C. and 350 r / min for 2 h. After the reaction stopped, the mixture was poured into a beaker, deionized water was added, and aged for 3 h. Finally, the mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain modified nano-silica; Step s5: weigh 50 parts of perfluoroether rubber PFR94, 2 parts of vulcanizing agent BIBP, 2 parts of crosslinking agent TAIC, 7 parts of carbon black N330, 4 parts of modified boron nitride, and 7 parts of modified nano-silica, and set aside; Step s6: adding perfluoroether rubber PFR94 to an internal mixer, mixing at 60° C. for 3 min, adding carbon black N330, modified boron nitride, and modified nano-silica, and continuing mixing at 80° C. for 8 min to obtain a rubber mixture; Step s7: Place the rubber mixture into an open mill to form sheets, place it in an oven and treat it at 180°C for 1 hour, add the vulcanizing agent BIBP and the cross-linking agent TAIC and mix them at 50°C for 3 minutes, stand for 24 hours after mixing, and then vulcanize it. Place the rubber mixture into a sealing ring mold for one-stage vulcanization at 160°C and 10MPa for 15 minutes, and then carry out the second-stage vulcanization at 180°C and 15MPa for 30 minutes. After the second-stage vulcanization, carry out the third-stage vulcanization at 200°C and 20MPa for 1 hour to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0027] Comparative Example 3: This comparative example is a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof, comprising the following steps: Step s1: 4.8 g of urea, 0.2 g of boric acid, and 1 g of glucose were added to an agate mortar and ground for 1.5 h. The ground powder was placed in a tube furnace, nitrogen was introduced, and the mixture was heated to 900 ° C at a heating rate of 5 ° C / min, and the calcination reaction was continued for 5 h. After the reaction was completed, the mixture was cooled to 25 ° C. The reaction product was ground for 30 min and added to ultrapure water. Ultrasonic dispersion was performed for 20 min, and then stirred for 30 min. The mixture was washed twice with a 37% hydrochloric acid solution by mass. The washed product was placed in a vacuum oven at 60 ° C and dried for 24 h to obtain carbon-doped boron nitride; Step s2: 1 g of carbon-doped boron nitride, 0.125 g of silane coupling agent KH-550, and 200 mL of toluene were added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube, and a constant pressure dropping funnel, mixed, and ultrasonically treated for 30 minutes. Nitrogen protection was introduced, heated to 110° C., and stirred for 8 hours. After the reaction was completed, the mixture was filtered, and the filter cake was washed twice with ethanol. It was then added to a vacuum freeze dryer and freeze-dried at -50° C. for 36 hours to obtain modified boron nitride; Step s3: 4 g of bismuth oxide particles with an average particle size of 50 nm were added to 35 mL of N,N-dimethylformamide, ultrasonically dispersed for 2 h, and then stirred for 4 h. 3 g of polyurethane WHT-3395 was added to the above solution, stirred at 25°C for 12 h, and added to an electrospinning apparatus using glossy paper as a receiving substrate for spinning. The mixture was then dried in a vacuum oven at 80°C for 2 h to obtain a bismuth oxide nanofiber membrane. Step s4: 3 g of gadolinium oxide nanosheets were heated and dried in a vacuum oven, added to 75 mL of deionized water, and stirred for 1 hour to obtain an aqueous dispersion of gadolinium oxide, 2 g of hexamethylene diisocyanate was added to the aqueous dispersion of gadolinium oxide to obtain an impregnation solution, 3 g of bismuth oxide nanofiber membranes were cut into 2×2 cm squares and stacked layer by layer, the stacked fiber membranes were placed in the impregnation solution, immersed for 2 hours, and frozen in liquid nitrogen to obtain a fiber membrane frozen block, and then the fiber membrane frozen block was placed in a freeze dryer for vacuum freeze drying for 24 hours, and then heated at 120° C. for 2 hours to obtain a cross-linked modified fiber membrane; Step s5: weigh 50 parts of perfluoroether rubber PFR94, 2 parts of vulcanizing agent BIBP, 2 parts of crosslinking agent TAIC, 7 parts of carbon black N330, 4 parts of modified boron nitride, and 10 parts of modified fiber membrane, and set aside; Step s6: adding perfluoroether rubber PFR94 to an internal mixer and mixing at 60°C for 3 minutes, adding carbon black N330 and modified boron nitride and mixing at 80°C for another 8 minutes, adding modified fiber membrane and mixing at 70°C for 5 minutes to obtain a mixed rubber; Step s7: Place the rubber mixture into an open mill to form sheets, place it in an oven and treat it at 180°C for 1 hour, add the vulcanizing agent BIBP and the cross-linking agent TAIC and mix them at 50°C for 3 minutes, stand for 24 hours after mixing, and then vulcanize it. Place the rubber mixture into a sealing ring mold for one-stage vulcanization at 160°C and 10MPa for 15 minutes, and then carry out the second-stage vulcanization at 180°C and 15MPa for 30 minutes. After the second-stage vulcanization, carry out the third-stage vulcanization at 200°C and 20MPa for 1 hour to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0028] Comparative Example 4: This comparative example is a radiation-resistant sealing ring for nuclear power equipment and a preparation method thereof, comprising the following steps: Step s1: 3 g of sodium silicate, 0.3 g of hexadecyltrimethylammonium bromide, 25 mL of anhydrous ethanol, and 25 g of sodium bicarbonate were added to a three-necked flask equipped with a stirrer, a thermometer, and an air guide tube. The mixture was stirred and modified at 55° C. and 300 rpm for 1 hour. After the modification, deionized water was added and aged for 3 hours. The mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain surfactant-coated nano-silica. Step s2: 15 g of surfactant-coated nano-silica, 23 mL of anhydrous ethanol, and 25 g of sodium bicarbonate were added to a reaction vessel, placed in a stirrer, and stirred at 55° C. and 375 r / min for 1 h. Then, 5 g of silane coupling agent KH-550 was added to the reaction vessel, stirred at 80° C. and 350 r / min for 2 h. After the reaction stopped, the mixture was poured into a beaker, deionized water was added, and aged for 3 h. Finally, the mixture was filtered using a vacuum pump, washed three times using a centrifuge, and then dried to obtain modified nano-silica; Step s3: 4 g of bismuth oxide particles with an average particle size of 50 nm were added to 35 mL of N,N-dimethylformamide, ultrasonically dispersed for 2 h, and then stirred for 4 h. 3 g of polyurethane WHT-3395 was added to the above solution, stirred at 25°C for 12 h, and added to an electrospinning apparatus using glossy paper as a receiving substrate for spinning. The mixture was then dried in a vacuum oven at 80°C for 2 h to obtain a bismuth oxide nanofiber membrane. Step s4: 3 g of gadolinium oxide nanosheets were heated and dried in a vacuum oven, added to 75 mL of deionized water, and stirred for 1 hour to obtain an aqueous dispersion of gadolinium oxide, 2 g of hexamethylene diisocyanate was added to the aqueous dispersion of gadolinium oxide to obtain an impregnation solution, 3 g of bismuth oxide nanofiber membranes were cut into 2×2 cm squares and stacked layer by layer, the stacked fiber membranes were placed in the impregnation solution, immersed for 2 hours, and frozen in liquid nitrogen to obtain a fiber membrane frozen block, and then the fiber membrane frozen block was placed in a freeze dryer for vacuum freeze drying for 24 hours, and then heated at 120° C. for 2 hours to obtain a cross-linked modified fiber membrane; Step s5: weigh 50 parts of perfluoroether rubber PFR94, 2 parts of vulcanizing agent BIBP, 2 parts of crosslinking agent TAIC, 7 parts of carbon black N330, 7 parts of modified nano-silica, and 10 parts of modified fiber membrane, and set aside; Step s6: adding perfluoroether rubber PFR94 to an internal mixer and mixing at 60°C for 3 minutes, adding carbon black N330 and modified nano-silica and mixing at 80°C for another 8 minutes, adding modified fiber membrane and mixing at 70°C for 5 minutes to obtain a mixed rubber; Step s7: Place the rubber mixture into an open mill to form sheets, place it in an oven and treat it at 180°C for 1 hour, add the vulcanizing agent BIBP and the cross-linking agent TAIC and mix them at 50°C for 3 minutes, stand for 24 hours after mixing, and then vulcanize it. Place the rubber mixture into a sealing ring mold for one-stage vulcanization at 160°C and 10MPa for 15 minutes, and then carry out the second-stage vulcanization at 180°C and 15MPa for 30 minutes. After the second-stage vulcanization, carry out the third-stage vulcanization at 200°C and 20MPa for 1 hour to obtain a radiation-resistant sealing ring for nuclear power equipment.

[0029] A radiation-resistant sealing ring for nuclear power equipment according to Examples 1-3 and Comparative Examples 1-4 was tested for radiation resistance, high temperature resistance, and pressure decay rate in accordance with the T / TLRIA0004-2018 standard. The pressure decay rate test method is as follows: at a constant temperature of 25°C, the initial sealing pressure is pressurized to 80% of the seal failure pressure, and the pressure holding value after 168 hours is recorded. The pressure decay rate (%) = (initial sealing pressure value - pressure holding value after 168 hours) / initial sealing pressure value × 100%. The test results are shown in the following table: .

[0030] As shown in the above table, based on the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen that the addition of modified boron nitride, modified nano-silica and modified fiber membrane can significantly improve the radiation resistance and high temperature resistance of the radiation-resistant sealing ring for nuclear power equipment, and the compressive resistance is also significantly improved.

[0031] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0032] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a radiation-resistant sealing ring for nuclear power equipment, characterized in that: The following steps are involved: Step 1: Weigh 50 parts of perfluoroether rubber, 2 parts of vulcanizing agent, 1-2 parts of cross-linking agent, 5-8 parts of reinforcing filler, 3-5 parts of modified boron nitride, 5-8 parts of modified nano-silica, and 10 parts of modified fiber membrane, and set aside; Step 2: adding the perfluoroether raw rubber into an internal mixer and mixing, then adding the reinforcing filler, modified boron nitride, and modified nano-silica and continuing to mix, adding the modified fiber membrane and mixing to obtain a mixed rubber; Step 3: Place the rubber mixture into an open mixer to form sheets, place the sheet into an oven for treatment, add a vulcanizing agent and a cross-linking agent for mixing, vulcanize after mixing, place the rubber mixture into a sealing ring mold for three-stage vulcanization, and obtain a radiation-resistant sealing ring for nuclear power equipment after vulcanization.

2. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 1, characterized in that: The perfluoroether rubber in step 1 is perfluoroether rubber PFR94; the vulcanizing agent is one of vulcanizing agent BIBP and vulcanizing agent bis 25; the cross-linking agent is cross-linking agent TAIC; and the reinforcing filler is carbon black N330.

3. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 1, characterized in that: The modified boron nitride is prepared by the following steps: Step a1: urea, boric acid and glucose were added to an agate mortar and ground for 1-2 hours. The ground powder was placed in a tube furnace, nitrogen was introduced, and the mixture was heated to 900°C at a heating rate of 5°C / min and calcined for 5 hours. After the reaction, the mixture was cooled to 25°C. The reaction product was ground for 30 minutes and added to ultrapure water for ultrasonic dispersion for 20 minutes, followed by stirring for 30 minutes. The mixture was washed with hydrochloric acid solution for 1-2 times, and the washed product was placed in a vacuum oven at 60°C and dried for 24 hours to obtain carbon-doped boron nitride. Step a2: Add carbon-doped boron nitride, a coupling agent, and toluene to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube, and a constant pressure dropping funnel, mix, and perform ultrasonic treatment for 30 minutes. Then, introduce nitrogen protection, heat to 110°C, and continue stirring to react for 8 hours. After the reaction is completed, filter, wash the filter cake with ethanol 1-2 times, and then add it to a vacuum freeze dryer and freeze-dry at -50°C for 24-48 hours to obtain modified boron nitride.

4. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 3, characterized in that: The usage ratio of the urea, boric acid and glucose in step a1 is 4.8g:0.2g:1g; the mass fraction of the hydrochloric acid solution is 36-38%; the usage ratio of the carbon-doped boron nitride, coupling agent and toluene in step a2 is 1g:0.125g:200mL: the coupling agent is silane coupling agent KH-550.

5. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 1, characterized in that: The modified nano-silica is prepared by the following steps: Step b1: Sodium silicate, an active agent, anhydrous ethanol, and sodium bicarbonate were added to a three-necked flask equipped with a stirrer, a thermometer, and an air guide tube, and the mixture was stirred and modified at 55°C and 300 rpm for 1 hour. After the modification, deionized water was added and aged for 3 hours. The mixture was filtered using a vacuum pump, washed 2-3 times using a centrifuge, and then dried to obtain surfactant-coated nano-silica. Step b2: Add surfactant-coated nano-silica, anhydrous ethanol, and sodium bicarbonate to a reaction vessel, place it in a stirrer, and stir the reaction at 55°C and 375r / min for 1h. Then add silane coupling agent KH-550 to the reaction vessel, stir the reaction at 60-100°C and 300-375r / min for 1-3h. After the reaction stops, pour it into a beaker, add deionized water, and age it for 3h. Finally, use a vacuum pump to filter, wash it 3 times with a centrifuge, and then dry it to obtain modified nano-silica.

6. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 5, characterized in that: The dosage ratio of the sodium silicate, active agent, anhydrous ethanol and sodium bicarbonate in step b1 is 1-5g:0.1-0.5g:20-30mL:23-26g; the active agent is one of cetyltrimethylammonium bromide, polyethylene glycol PEG6000 and sodium dodecylbenzenesulfonate.

7. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 5, characterized in that: The usage ratio of the surfactant-coated nano-silica, anhydrous ethanol, sodium bicarbonate and silane coupling agent KH-550 in step b2 is 10-20 g: 20-25 mL: 23-26 g: 1-10 g.

8. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 1, characterized in that: The modified fiber membrane is prepared by the following steps: Step c1: adding bismuth oxide particles with an average particle size of 50 nm to N,N-dimethylformamide, ultrasonically dispersing for 2 hours and then stirring for 4 hours, adding polyurethane to the above solution, stirring at 25°C for 12 hours, adding the solution to an electrospinning apparatus using glossy paper as a receiving substrate for spinning, and then drying in a vacuum oven at 80°C for 2 hours to obtain a bismuth oxide nanofiber membrane; Step c2: Heat and dry the gadolinium oxide nanosheets in a vacuum oven, add them to deionized water, and stir for 1 hour to obtain an aqueous dispersion of gadolinium oxide, add a binder to the above-mentioned aqueous dispersion of gadolinium oxide to obtain an impregnation solution, cut the bismuth oxide nanofiber membrane into 2×2 cm squares, and stack them layer by layer, place the stacked fiber membranes into the impregnation solution, soak for 2 hours, and freeze them in liquid nitrogen to obtain fiber membrane frozen blocks, then place the fiber membrane frozen blocks in a freeze dryer and vacuum freeze-dry for 24 hours, and then heat them at 120°C for 2 hours to obtain a cross-linked modified fiber membrane.

9. The method for preparing a radiation-resistant sealing ring for nuclear power equipment according to claim 8, characterized in that: The usage ratio of the bismuth oxide particles, N,N-dimethylformamide and polyurethane in step c1 is 2-5g:20-50mL:1-5g: the polyurethane is polyurethane WHT-3395; the usage ratio of the gadolinium oxide nanosheets, deionized water, adhesive and bismuth oxide nanofiber membrane in step c2 is 1-5g:50-100mL:1-3g:1-5g; the adhesive is hexamethylene diisocyanate.

10. A radiation-resistant sealing ring for nuclear power equipment, characterized in that: The radiation-resistant sealing ring for nuclear power equipment is prepared by the preparation method of the radiation-resistant sealing ring for nuclear power equipment according to any one of claims 1 to 9.