Anisotropic radiation-resistant rubber and preparation method thereof

Abstract

The invention relates to the technical field of anisotropic rubber, and particularly discloses anisotropic radiation-resistant rubber and a preparation method thereof, aiming at the problems that rubber used in nuclear industry such as shock absorption and isolation rubber components is always easy to crack, discolor, harden and the like due to the influence of a nuclear radiation environment at present, and particularly discloses the anisotropic radiation-resistant rubber and the preparation method thereof. Comprising 10%-30% of a rubber matrix, 65%-68% of irradiation-resistant particles, 1%-3.5% of an active agent, 1.2%-3.7% of an anti-aging agent, 3%-5% of a reinforcing agent, 0.8%-1.2% of a softening agent, 0%-0.2% of an accelerant and 0.5%-1.2% of a vulcanizing agent. Each radiation-resistant particle comprises a core layer, a middle layer and a shell layer, the core layer comprises lead tungstate and bismuth oxide, the middle layer comprises a biphenyl-nano SiO2 bonding body, and the shell layer comprises diphenyl acetylene grafted graphene oxide. By introducing the radiation-resistant particles with multiple structures and functional characteristics, the material performance stability of the anisotropic rubber in a radiation environment can be remarkably improved, so that the use requirements of the fields and scenes such as nuclear industry devices and the like are met.

Description

Technical Field

[0001] The present invention relates to the technical field of anisotropic rubber, in particular to anisotropic radiation-resistant rubber and a preparation method thereof. Background Art

[0002] Anisotropy refers to the variation in all or part of a substance's chemical or physical properties with changes in direction, exhibiting different properties in different directions. Rubber is a type of flexible polymer with long molecular chains. Through special design or processing, its internal structure can be spatially directional due to factors such as molecular chain alignment, filler distribution, and reinforcement orientation. This results in significant differences in physical and mechanical properties depending on the measured direction.

[0003] Rubber is widely used in fields such as aerospace, rail transportation, shipbuilding and nuclear industry because of its characteristics such as high elasticity, large deformation and amorphous. As the patent of publication number CN112980122A, a kind of mechanical anisotropic rubber and preparation method thereof have been proposed, fluoroether rubber emulsion is adopted to mix with nanofiller, then flocculant, acid scavenger, vulcanizing agent and co-vulcanizing agent are mixed, and the mechanical anisotropic rubber is prepared through operations such as vulcanization mixing. When nanofiller is uniformly dispersed in rubber inside, mode such as external field effect such as mechanical stretching is relied on, and on low crosslinking degree, fast molecular chain orientation and the directional arrangement of filler are realized, by further directional stretching etc., the anisotropic fluoroether rubber material with the good directional arrangement of one-dimensional nanofiller is obtained, effectively improving the mechanical property of rubber.

[0004] However, in applications in the nuclear field, such as as shock-absorbing and isolating rubber components, the rubber will always suffer damage and destruction such as cracking, discoloration, and hardening due to the influence of the nuclear radiation environment. That is, the existing anisotropic rubber has the problem of performance degradation in the nuclear radiation environment. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem that rubber currently used in the nuclear industry, such as vibration-isolating rubber components, is always susceptible to damage such as cracking, discoloration, and hardening due to the influence of nuclear irradiation environment, resulting in performance degradation.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention provides an anisotropic radiation-resistant rubber, which comprises the following raw material components, calculated by mass fraction: 10-30% of a rubber matrix, 65-68% of radiation-resistant particles, 1-3.5% of an active agent, 1.2-3.7% of an antioxidant, 3-5% of a reinforcing agent, 0.8-1.2% of a softener, 0-0.2% of an accelerator, and 0.5-1.2% of a vulcanizing agent; wherein the radiation-resistant particles comprise a core layer, an intermediate layer, and a shell layer, and the core layer comprises lead tungstate and bismuth oxide, the intermediate layer comprises a biphenyl-nano-SiO2 bonded body, and the shell layer comprises diphenylacetylene-grafted graphene oxide.

[0008] Preferably, in the radiation-resistant particles, the mass ratio of lead tungstate to bismuth oxide in the core layer is 7:2-5.

[0009] 3. The anisotropic radiation-resistant rubber according to claim 1 is characterized in that, preferably, in the particles, the thickness of the core layer accounts for 40-50% of the particle size of the radiation-resistant particles, the thickness of the middle layer accounts for 30-35% of the particle size of the radiation-resistant particles, and the thickness of the shell layer accounts for 20-25% of the particle size of the radiation-resistant particles.

[0010] Preferably, the method for preparing the radiation-resistant particles comprises the following steps:

[0011] A1: Mix lead tungstate and bismuth oxide, add a dispersant, stir evenly, and dry-mill until core layer particles with a particle size of 6.5-9 μm are obtained;

[0012] A2: placing the core layer particles in an ethanol aqueous solution and ultrasonically dispersing them; then taking out the core layer particles, adding them to a biphenyl solution, heating them to 50-80°C, and then adding ethyl orthosilicate dropwise at a uniform rate under stirring to react. Finally, solid-liquid separation and centrifugal washing are performed to obtain middle layer particles with biphenyl-nano-SiO2 bonded bodies coated on the surface;

[0013] A3 takes the middle layer particles and graphene oxide, disperses them in a solvent, then adds diphenylacetylene and a catalyst, and then irradiates them with microwaves under nitrogen protection, followed by centrifugal separation and shaping by drying and spraying to obtain radiation-resistant particles with a surface grafted shell.

[0014] Preferably, in step A1, the ball-to-material ratio is 8-12:1, and dry ball milling is performed at 350-450 rpm.

[0015] Preferably, in step A2, the molar ratio of the total amount of ethyl orthosilicate added to biphenyl is controlled to be 1:0.1-0.3.

[0016] Preferably, in step A3, the flake diameter of the graphene oxide is 1-5 μm, and the mass ratio of the middle layer particles to the graphene oxide is 8-15:1.

[0017] Preferably, in step A3, 800 W microwave irradiation is used, and the pulse mode is on 10 s / off 5 s, for a total of 3-8 min.

[0018] The present invention also provides a method for preparing the above-mentioned anisotropic radiation-resistant rubber, comprising the following steps:

[0019] S1: Rubber matrix, active agent, antioxidant, reinforcing agent, and softener are weighed and placed in an internal mixer, heated to 70-120°C, and mixed; then, radiation-resistant particles and vulcanizing agent are added, and mixing is continued until uniform to obtain a rubber compound;

[0020] S2 places the mixed rubber in an open mill with an open mill temperature of 80-100°C, rolls the mixture, and then injects it into a vulcanization mold; places the vulcanization mold under a strong electric field, heats it to 90-100°C, and performs pre-structural treatment; then uses a vulcanizer to control the temperature at 150-180°C and perform vulcanization treatment to obtain the anisotropic radiation-resistant rubber.

[0021] Preferably, in step S2, during the prestructuring treatment, the electric field strength is 100-500 kV / mm, and the treatment time is 0.5-2 h; during the vulcanization treatment, the treatment time is 10-18 min.

[0022] The technical solution of the present invention has the following beneficial effects:

[0023] The anisotropic radiation-resistant rubber of the present invention introduces radiation-resistant particles with multiple layers of different functional structures, and utilizes a three-dimensional network and chain structure to enhance the absorption of radiation energy, thereby significantly improving the radiation protection performance of the anisotropic rubber to protect the radiation stability of the rubber matrix material; and with the help of an external excitation field, the aggregation state of the rubber reinforcing particles can be regulated, thereby promoting the long-term stability of the morphology and performance of the rubber material.

[0024] The radiation-resistant particles form a three-dimensional network of particles and a chain-like structure within the rubber matrix. This increases the number of reflections of radiation between the internal particle chains, enhancing the absorption and dissipation of radiation energy, and improving the radiation energy absorption and shielding effect of the polymer rubber matrix. This ensures that the rubber material can withstand higher doses of radiation, thereby enhancing the rubber material's radiation resistance. Experimental verification has shown that the anisotropic rubber material proposed in this invention retains high mechanical strength after gamma-ray irradiation, with minimal mechanical strength degradation, stable material properties, and significant radiation resistance. It can be widely and effectively applied in fields such as nuclear industry devices and scenarios. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed; and where the manufacturers of the instruments, equipment, reagents, and raw materials used are not specified, they are all commercially available conventional products.

[0026] The invention provides an anisotropic radiation-resistant rubber. The anisotropic radiation-resistant rubber comprises the following raw material components, calculated by mass fraction: 10-30% of a rubber matrix, 65-68% of radiation-resistant particles, 1-3.5% of an active agent, 1.2-3.7% of an antioxidant, 3-5% of a reinforcing agent, 0.8-1.2% of a softener, 0-0.2% of an accelerator, and 0.5-1.2% of a vulcanizing agent.

[0027] In the present invention, the radiation-resistant particles are multi-layer core-shell structure materials, mainly including a core layer with high-density gamma ray shielding, an intermediate layer for neutron absorption and radiation degradation resistance, and a shell layer with surface interface strengthening and free radical capture capabilities.

[0028] The core material is mainly lead tungstate and bismuth oxide with a mass ratio of 7:2-5, accounting for 40-50% of the total radiation-resistant particle size. The two can synergistically play a gamma ray shielding role, reaching 2.4cm at an energy of 100keV. -1 .

[0029] The intermediate layer material is mainly biphenyl-nano-SiO2 bonded body, through the dehydration condensation of biphenyl benzene ring and nano-SiO2 surface silanol to form a covalently bonded organic-inorganic hybrid layer, and the mass ratio of biphenyl to nano-SiO2 is 1:5-10, and the Si-OC bond density is ≥5bonds / nm 2 , accounting for 30-35% of the total radiation-resistant particle size, which can inhibit cracking that may occur in an irradiation environment;

[0030] The shell material is mainly diphenylacetylene grafted graphene oxide, which is formed by the esterification reaction of the edge carboxyl group of graphene oxide and the diphenylacetylene alkynyl group. It has a three-dimensional free radical capture network structure, accounts for 20-25% of the entire radiation-resistant particle size, and has an interlayer spacing of 1.2-1.8nm.

[0031] In the present invention, the method for preparing the radiation-resistant particles comprises the following steps:

[0032] (1) Lead tungstate and D 50 =5μm bismuth oxide powder is mixed according to the amount, and 0.3-0.8wt% of the total mass of the mixed material as a zinc stearate dispersant is added, stirred evenly, placed in a ball mill, using zirconium oxide balls as ball milling bodies, controlling the ball-to-material ratio to 8-12:1, and dry grinding at 350-450rpm to obtain a particle size D 90The core layer particles are about 6.5-9 μm in size, the sphericity of the core layer material is greater than 0.92, and the porosity is less than 3.0%.

[0033] (2) placing the core layer particles in an ethanol aqueous solution, wherein the volume ratio of ethanol to water can be controlled at 3-5:1, and ultrasonically treating for 25-40 minutes; then taking out the core layer particles, adding them to a mixture of 10-20wt% biphenyl ethanol solution and ammonia water, heating to 50-80°C, stirring, and uniformly adding ethyl orthosilicate dropwise, and controlling the total amount of ethyl orthosilicate added to the molar ratio of biphenyl to 1:0.1-0.3, reacting for 3.5-5 hours, and then solid-liquid separation, centrifugal washing, and obtaining middle layer particles with a surface coated with a biphenyl-nano-SiO2 middle layer, wherein the coating thickness of the middle layer is 20±5nm.

[0034] (3) The middle layer particles and graphene oxide with a sheet diameter of about 1-5 μm are dispersed in 1-2 times the volume of dimethylformamide solvent at a mass ratio of 8-15:1; diphenylacetylene and dicyclohexylcarbodiimide catalysts are then added, and under nitrogen protection, 800 W microwave irradiation is performed with a pulse mode of on 10 s / off 5 s for a total of 3-8 min. The unreacted products are then removed by centrifugation, and the particles are shaped by spray drying to obtain radiation-resistant particles with a surface grafted shell layer, the particle size of which is 15-55 μm and the tap density is about 2.1±0.1 g / cm 3 .

[0035] The radiation-resistant particles in the present invention can form three-dimensional network particles and chain structures in the rubber matrix. By increasing the number of reflections of radiation rays between internal particle chains, the absorption and dissipation of radiation energy are increased, and the radiation energy absorption and shielding effect of the polymer rubber matrix are improved, thereby ensuring that the rubber material can withstand higher doses of radiation, thereby achieving the effect of enhancing the radiation resistance of the rubber material.

[0036] In the present invention, the rubber matrix includes but is not limited to one or more of phenylene silicone rubber, phenylene ether silicone rubber, natural rubber, butadiene rubber, isoprene rubber and the like.

[0037] In the present invention, the active agent includes but is not limited to one or more of zinc oxide, stearic acid, magnesium oxide, white carbon black, alkylphenol polysulfide compounds, and the like.

[0038] In the present invention, the antioxidant includes but is not limited to one or more of 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, N-phenyl-α-aniline, N-phenyl-β-naphthylamine, N-N'-diphenyl-p-phenylenediamine, 4,4'-bis(2,2-dimethylbenzyl)diphenylamine, N-isopropyl-N'-phenyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydro-p-quinoline dimer, microcrystalline wax, paraffin, N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine, etc.

[0039] In the present invention, the reinforcing agent includes but is not limited to one or more of carbon black, precipitated calcium carbonate, white carbon black, magnesium carbonate, zinc oxide, and the like.

[0040] In the present invention, the softener includes but is not limited to one or more of paraffins, cycloalkanes, aromatic hydrocarbons, nitrogen-containing organic bases, coal tar, coumarone resin, coal pitch, vegetable oil, fatty acid, ointment, pine tar, rosin, tall oil, wood pitch, etc.

[0041] In the present invention, the accelerator includes but is not limited to one or more of N-cyclohexyl-2-benzoxazolyl sulfenamide, tetramethylthiuram disulfide, guanidines, aldehyde amines, thioureas, dithiocarbamates, xanthates, sulfenamide compounds, etc.

[0042] In the present invention, the vulcanizing agent includes but is not limited to one or more of sulfur, zinc oxide, magnesium oxide, lead oxide, lead tetroxide, alkylphenol-formaldehyde resin, epoxy resin, tetramethylthiuram disulfide, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, diisopropylbenzene peroxide, etc.

[0043] The present invention also provides a method for preparing the above-mentioned anisotropic radiation-resistant rubber, comprising the following steps:

[0044] (1) taking the rubber matrix, active agent, antioxidant, reinforcing agent, softener and accelerator according to the amount, putting them into an internal mixer, heating to 70-120° C., and mixing them thoroughly; then adding the radiation-resistant particles and vulcanizing agent, and continuing to mix until uniform, to obtain a rubber compound;

[0045] (2) The mixed rubber is placed in an open mill at a refining temperature of 80-100°C, rolled, and then injected into a vulcanization mold; the vulcanization mold is placed under a strong electric field, the electric field strength is controlled to be 100-500kV / mm, the temperature is 90-100°C, and a pre-structural treatment is performed for 0.5-2h; then a high-temperature flat vulcanizing press is used, the temperature is controlled to be 150-180°C, and a vulcanization treatment is performed for 10-18min to obtain anisotropic radiation-resistant rubber.

[0046] Example 1

[0047] 112.5g of lead tungstate and 57.2g of bismuth oxide were mixed, followed by 0.85g of zinc stearate, stirred thoroughly, and placed in a ball mill using zirconium oxide balls at a ball-to-material ratio of 10:1. Dry grinding was performed at 400 rpm to produce core-layer particles with a particle size of approximately 8μm. An ethanol-water solution was prepared at a volume ratio of 4:1. The core-layer particles were placed in the ethanol-water solution and ultrasonically treated for 30 minutes. The core-layer particles were then removed and added to an ethanol solution containing 15wt% biphenyl. Ammonia was added dropwise to a pH of 9.0. The solution was heated to 60°C and, while stirring at 200 rpm, tetraethyl orthosilicate was added dropwise at a constant rate, with a total molar ratio of tetraethyl orthosilicate to biphenyl of 1:0.2. The reaction was allowed to proceed for 4 hours, forming intermediate-layer particles with a particle size of approximately 14.8μm, coated with biphenyl-nano-SiO2 bonds. The particles were then removed for solid-liquid separation and centrifugal washing. The middle-layer particles were mixed with graphene oxide with a flake diameter of 2.5 μm in a mass ratio of 10:1 and dispersed in 1.25 times the volume of dimethylformamide solvent; then 0.1 mol / L diphenylacetylene and dicyclohexylcarbodiimide with the same mass as the graphene oxide were added, placed in a nitrogen protection environment, and irradiated with 800 W microwaves in a pulse mode of on 10 s / off 5 s for a total of 5 min. After being taken out, the particles were centrifuged and spray-dried at an inlet temperature of 180°C and an outlet temperature of 80°C, an atomization pressure of 0.8 MPa, and a feed rate of 10 mL / min to obtain radiation-resistant particles with a particle size of approximately 19.6 μm.

[0048] Example 2

[0049] (1) By mass percentage, 65% of the radiation-resistant particles prepared in Example 1, 25% of phenylene silicone rubber, 0.2% of zinc oxide, 0.8% of stearic acid, 2% of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 5% of carbon black, 1.2% of dibutyl phthalate, 0.1% of N-cyclohexyl-2-benzoxazolylsulfenamide, and 0.7% of 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane were taken and set aside.

[0050] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 70°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to mix until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled at 95°C, and the open mixing was performed with rollers. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 300 kV / mm and a temperature of 100°C. The pre-structural treatment was performed for 1 hour. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain anisotropic radiation-resistant rubber.

[0051] Example 3

[0052] (1) By mass percentage, 68% of the radiation-resistant particles prepared in Example 1, 22% of phenylene ether silicone rubber, 1.5% of zinc oxide, 1.6% of 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 1.1% of paraffin wax, 4.4% of magnesium carbonate, 0.9% of tall oil, and 0.5% of 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane were taken and set aside.

[0053] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 70°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to mix until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled at 95°C, and the open mixing was performed with rollers. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 300 kV / mm and a temperature of 100°C. The pre-structural treatment was performed for 1 hour. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain anisotropic radiation-resistant rubber.

[0054] Example 4

[0055] (1) By mass percentage, 70% of the radiation-resistant particles prepared in Example 1, 10% of natural rubber, 10% of butadiene rubber, 2.2% of magnesium oxide, 1.2% of N-isopropyl-N'-phenyl-p-phenylenediamine, 5.1% of white carbon black, 0.86% of coumarone resin, 0.1% of tetramethylthiuram disulfide, and 0.54% of sulfur were taken and set aside.

[0056] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 70°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to mix until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled at 95°C, and the open mixing was performed with rollers. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 300 kV / mm and a temperature of 100°C. The pre-structural treatment was performed for 1 hour. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain anisotropic radiation-resistant rubber.

[0057] Example 5

[0058] (1) By mass percentage, 66% of the radiation-resistant particles prepared in Example 1, 20% of isoprene rubber, 2.7% of stearic acid, 0.8% of N-phenyl-α-aniline, 0.8% of N-phenyl-β-naphthylamine, 7.93% of white carbon black, 0.96% of coumarone resin, 0.08% of N-cyclohexyl-2-benzoxazolylsulfenamide, and 0.73% of sulfur were taken and set aside.

[0059] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 70°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to mix until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled at 95°C, and the open mixing was performed with rollers. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 300 kV / mm and a temperature of 100°C. The pre-structural treatment was performed for 1 hour. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain anisotropic radiation-resistant rubber.

[0060] Example 6

[0061] (1) By mass percentage, 68% of the radiation-resistant particles prepared in Example 1, 22% of phenylene ether silicone rubber, 1.5% of zinc oxide, 0.6% of 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 1.1% of paraffin wax, 4.4% of magnesium carbonate, 0.9% of tall oil, and 0.5% of 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane were taken and set aside.

[0062] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfonamide were mixed and placed in an internal mixer. The mixture was heated to 85°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to mix until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled to 100°C, and the open mixing was performed with a roller. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 500 kV / mm and a temperature of 90°C. The mold was pre-structured for 2 hours. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain anisotropic radiation-resistant rubber.

[0063] Example 7

[0064] (1) By mass percentage, 70% of the radiation-resistant particles prepared in Example 1, 10% of natural rubber, 10% of butadiene rubber, 2.2% of magnesium oxide, 1.2% of N-isopropyl-N'-phenyl-p-phenylenediamine, 5.1% of white carbon black, 0.86% of coumarone resin, 0.1% of tetramethylthiuram disulfide, and 0.54% of sulfur were taken and set aside.

[0065] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 78°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to be mixed until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled at 95°C, and the open mixing was performed with a roller. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 100 kV / mm and a temperature of 92°C. The pre-structural treatment was performed for 1 hour. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 150°C for 10 minutes to obtain anisotropic radiation-resistant rubber.

[0066] Example 8

[0067] (1) By mass percentage, 66% of the radiation-resistant particles prepared in Example 1, 20% of isoprene rubber, 2.7% of stearic acid, 0.8% of N-phenyl-α-aniline, 0.8% of N-phenyl-β-naphthylamine, 7.93% of white carbon black, 0.96% of coumarone resin, 0.08% of N-cyclohexyl-2-benzoxazolylsulfenamide, and 0.73% of sulfur were taken and set aside.

[0068] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 72°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to mix until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled to 80°C, and the open mixing was performed with a roller. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 400 kV / mm and a temperature of 95°C. The pre-structural treatment was performed for 1 hour and 20 minutes. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 170°C for 15 minutes to obtain anisotropic radiation-resistant rubber.

[0069] Comparative Example 1

[0070] (1) By mass percentage, 20% of the radiation-resistant particles prepared in Example 1, 70% of phenylene silicone rubber, 0.2% of zinc oxide, 0.8% of stearic acid, 2% of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 5% of carbon black, 1.2% of dibutyl phthalate, 0.1% of N-cyclohexyl-2-benzoxazolamide, and 0.7% of 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were taken and set aside.

[0071] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 70°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to be mixed until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled to 95°C, and the open mixing was performed with a roller. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 300 kV / mm and a temperature of 100°C. The pre-structural treatment was performed for 1 hour. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain a rubber product.

[0072] Comparative Example 2

[0073] (1) Take 10% lead tungstate, 8% biphenyl, 7% nano-silica, 65% phenylene silicone rubber, 0.2% zinc oxide, 0.8% stearic acid, 2% 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 5% carbon black, 1.2% dibutyl phthalate, 0.1% N-cyclohexyl-2-benzoxazolamide, and 0.7% 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane respectively by mass percentage and set aside.

[0074] (2) First, lead tungstate, biphenyl, and nano-silica are ball-milled to form clusters to obtain a radiation-resistant composite agent; phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfonamide are mixed and placed in an internal mixer, heated to 70°C, and fully mixed. Then, the radiation-resistant composite agent and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane are added and mixed until homogeneous to obtain a rubber compound. The rubber compound is transferred to an open mixer, the open mixing temperature is controlled at 95°C, and the open mixing is performed with a roller. Then, the rubber compound is placed in a vulcanization mold, and the vulcanization mold is placed under a strong electric field with an electric field strength of 300 kV / mm and a temperature of 100°C. The pre-structural treatment is performed for 1 hour. Finally, the mold is transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain a rubber product.

[0075] Comparative Example 3

[0076] (1) Take 25 parts of phenylene silicone rubber, 0.2 parts of zinc oxide, 0.8 parts of stearic acid, 2 parts of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 5 parts of carbon black, 1.2 parts of dibutyl phthalate, 0.1 parts of N-cyclohexyl-2-benzoxazolamide, and 0.7 parts of 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane respectively and set aside.

[0077] (2) Phenylene silicone rubber, zinc oxide, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, carbon black, dibutyl phthalate, and N-cyclohexyl-2-benzoxazolyl sulfenamide were mixed and placed in an internal mixer. The mixture was heated to 70°C and fully mixed. Then, radiation-resistant particles and 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane were added and the mixture was continued to be mixed until homogeneous to obtain a rubber compound. The rubber compound was transferred to an open mixer, the open mixing temperature was controlled to 95°C, and the open mixing was performed with a roller. The rubber compound was then placed in a vulcanization mold. The vulcanization mold was placed under a strong electric field with an electric field strength of 300 kV / mm and a temperature of 100°C. The pre-structural treatment was performed for 1 hour. Finally, the mold was transferred to a flat vulcanizer and vulcanized at 180°C for 10 minutes to obtain a rubber product.

[0078] Test example

[0079] Samples: radiation-resistant particles prepared in Example 1, anisotropic radiation-resistant rubbers prepared in Examples 2-8, and rubbers prepared in Comparative Documents 1-3.

[0080] The above samples were taken and tested according to GB / T531.1-2008 "Rubber, vulcanized or thermoplastic rubber - Determination of indentation hardness (Shore durometer method)" and GB / T 528-2009 "Rubber, vulcanized or thermoplastic rubber - Determination of tensile stress-strain properties". The Shore hardness, tensile strength and elongation at break of the samples were tested before and after irradiation. The results are summarized in Table 1 below:

[0081] Table 1 Material performance test results of different samples before and after irradiation

[0082]

[0083]

[0084] The above experiments and test results indicate that the anisotropic radiation-resistant rubbers of Examples 2 to 8, using the anisotropic radiation-resistant rubbers of the present invention, maintain comparable pre-irradiation performance after gamma-ray irradiation, or experience only a slight decrease in performance. In contrast, the rubbers of Comparative Examples 1 to 3, which utilize minimal amounts of radiation-resistant particles, conventional radiation-resistant agents, or even no radiation-resistant component, exhibit significant performance degradation after gamma-ray irradiation. This demonstrates that the anisotropic radiation-resistant rubber and its preparation method of the present invention effectively address the performance degradation issue of existing anisotropic rubbers in irradiated environments, and can be widely and effectively applied to fields and scenarios such as nuclear industry devices.

[0085] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An anisotropic radiation-resistant rubber, characterized in that: Calculated by mass, the raw material components include: 10-30% rubber matrix, 65-68% radiation-resistant particles, 1-3.5% active agent, 1.2-3.7% antioxidant, 3-5% reinforcing agent, 0.8-1.2% softener, 0-0.2% accelerator, and 0.5-1.2% vulcanizing agent; The radiation-resistant particles include a core layer, an intermediate layer and a shell layer, and the core layer includes lead tungstate and bismuth oxide, the intermediate layer includes a biphenyl-nano-SiO2 bonded body, and the shell layer includes diphenylacetylene grafted graphene oxide.

2. The anisotropic radiation-resistant rubber according to claim 1, characterized in that: In the radiation-resistant particles, the mass ratio of lead tungstate to bismuth oxide in the core layer is 7:2-5.

3. The anisotropic radiation-resistant rubber according to claim 1, characterized in that: In the radiation-resistant particles, the thickness of the core layer accounts for 40-50% of the particle size of the radiation-resistant particles, the thickness of the middle layer accounts for 30-35% of the particle size of the radiation-resistant particles, and the thickness of the shell layer accounts for 20-25% of the particle size of the radiation-resistant particles.

4. The anisotropic radiation-resistant rubber according to claim 1, characterized in that: The method for preparing the radiation-resistant particles comprises the following steps: A1: Mix lead tungstate and bismuth oxide, add a dispersant, stir evenly, and dry-mill until core layer particles with a particle size of 6.5-9 μm are obtained; A2: placing the core layer particles in an ethanol aqueous solution and ultrasonically dispersing them; then taking out the core layer particles, adding them to a biphenyl solution, heating them to 50-80°C, and then adding ethyl orthosilicate dropwise at a uniform rate under stirring to react. Finally, solid-liquid separation and centrifugal washing are performed to obtain middle layer particles with biphenyl-nano-SiO2 bonded bodies coated on the surface; A3 takes the middle layer particles and graphene oxide, disperses them in a solvent, then adds diphenylacetylene and a catalyst, and then irradiates them with microwaves under nitrogen protection, followed by centrifugal separation and shaping by drying and spraying to obtain radiation-resistant particles with a surface grafted shell.

5. The anisotropic radiation-resistant rubber according to claim 4, characterized in that: In step A1, the ball-to-material ratio is 8-12:1, and dry ball milling is performed at 350-450 rpm.

6. The anisotropic radiation-resistant rubber according to claim 4, characterized in that: In step A2, the molar ratio of the total amount of ethyl orthosilicate added to biphenyl is controlled to be 1:0.1-0.

3.

7. The anisotropic radiation-resistant rubber according to claim 4, characterized in that: In step A3, the diameter of the graphene oxide flakes is 1-5 μm, and the mass ratio of the middle layer particles to the graphene oxide is 8-15:

1.

8. The anisotropic radiation-resistant rubber according to claim 4, characterized in that: In step A3, 800 W microwave irradiation is used, and the pulse mode is on 10 s / off 5 s, for a total of 3-8 min.

9. A method for preparing the anisotropic radiation-resistant rubber according to any one of claims 1 to 8, characterized in that: The steps include: S1: Rubber matrix, active agent, antioxidant, reinforcing agent, and softener are weighed and placed in an internal mixer, heated to 70-120°C, and mixed; then, radiation-resistant particles and vulcanizing agent are added, and mixing is continued until uniform to obtain a rubber compound; S2 places the mixed rubber in an open mill with an open mill temperature of 80-100°C, rolls the mixture, and then injects it into a vulcanization mold; places the vulcanization mold under a strong electric field, heats it to 90-100°C, and performs pre-structural treatment; then uses a vulcanizer to control the temperature at 150-180°C and perform vulcanization treatment to obtain the anisotropic radiation-resistant rubber.

10. The method for preparing anisotropic radiation-resistant rubber according to claim 9, characterized in that: In step S2, during the prestructuring treatment, the electric field strength is 100-500 kV / mm and the treatment time is 0.5-2 hours; during the vulcanization treatment, the treatment time is 10-18 minutes.

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