Radiation-resistant ethylene propylene diene monomer rubber based on multidentate ligand perovskite nanocrystals and preparation method of radiation-resistant ethylene propylene diene monomer rubber

Abstract

The invention discloses irradiation-resistant ethylene propylene diene monomer based on polydentate ligand perovskite nanocrystals and a preparation method thereof, and belongs to the technical field of rubber material modification. The EPDM rubber material is prepared from the following components in parts by weight: 100 parts of EPDM rubber, 30 to 80 parts of reinforcing filler, 0.5 to 10 parts of polydentate ligand perovskite nanocrystalline CsPbBr3, 0.5 to 5 parts of lead polyacrylate, 0.5 to 6 parts of polyphenyl vinyl silane, 1 to 5 parts of vulcanizing agent and 0 to 4 parts of assistant crosslinking agent. The ethylene propylene diene monomer has excellent irradiation resistance, still keeps good mechanical properties in an irradiation environment, and is longer in service life.

Description

Technical Field

[0001] This application relates to a radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals and its preparation method, belonging to the field of rubber material modification technology. Background Technology

[0002] Ethylene propylene diene monomer (EPDM) rubber is a saturated rubber copolymerized from ethylene, propylene, and a small amount of non-conjugated dienes. It possesses excellent heat resistance, ozone resistance, weather resistance, and electrical insulation properties, and is widely used in cable sheathing, sealing rings, aerospace seals, and nuclear industry insulation materials. However, under high-energy radiation environments, EPDM molecular chains are susceptible to bombardment by high-energy particles such as gamma rays and electron beams, resulting in free radical reactions that cause molecular chain breakage or excessive cross-linking. This leads to a significant deterioration in the material's mechanical properties, elasticity, and insulation properties, thus limiting its application in high-radiation environments.

[0003] Existing methods for improving the radiation resistance of EPDM rubber mainly include adding inorganic fillers, introducing free radical scavengers, or constructing cross-linked network structures. For example, commonly used inorganic fillers such as carbon black, zinc oxide, and titanium dioxide can absorb radiation energy and inhibit free radical reactions to a certain extent, but they suffer from poor interfacial compatibility and poor dispersibility, which often weakens the flexibility and tensile properties of the rubber. While organic antioxidants or hindered phenolic radiation-resistant agents can inhibit free radical generation in the short term, they are prone to migration or failure under high radiation conditions, resulting in insufficient durability.

[0004] Perovskite nanocrystals, as a novel type of inorganic-organic hybrid semiconductor material, possess excellent bandgap modulation capabilities and efficient energy absorption and transfer performance. Currently, perovskite nanocrystals are mainly used in optoelectronics, luminescence, and radiation detection, while their application in the radiation resistance modification of rubber is still in its early stages. If highly stable perovskite nanocrystals can be uniformly dispersed in an EPDM rubber matrix, their excellent energy absorption and electron trapping capabilities could effectively suppress radiation-induced free radical reactions, significantly improving the radiation resistance and service life of EPDM rubber. However, it is necessary to consider the high temperatures easily induced by irradiation, and the poor temperature resistance of perovskite nanocrystals. Therefore, developing a novel radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals that can also improve its temperature resistance shortcomings has significant engineering application value and scientific significance. Summary of the Invention

[0005] This application addresses the problems of molecular chain breakage, uneven cross-linking, and performance degradation of EPDM rubber under high-energy irradiation in the prior art. It provides an irradiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals and its preparation method. By introducing multidentate ligand perovskite nanocrystals, lead polyacrylate, and polyphenylvinylsilane, the absorption and energy dissipation capacity of the material for high-energy radiation are improved, thereby significantly enhancing the structural stability and mechanical retention of EPDM rubber.

[0006] According to the first aspect of this application, this application provides a radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals, comprising the following components by weight: 100 parts of EPDM rubber, 30-80 parts of reinforcing filler, 0.5-10 parts of multidentate ligand perovskite nanocrystals CsPbBr3, 0.5-5 parts of lead polyacrylate, 0.5-6 parts of polyphenylvinylsilane, 1-5 parts of vulcanizing agent, and 0-4 parts of co-crosslinking agent; The structural formula of the polyphenylvinylsilane is as follows: .

[0007] Perovskite nanocrystals CsPbBr3 possess strong carrier trapping and energy dissipation capabilities. Under irradiation conditions, they can reduce the effective transfer of irradiation energy in the rubber matrix, thereby weakening the generation and diffusion of irradiation-induced active free radicals. The presence of multidentate ligand layers further forms a "free radical buffer-capture" dual system, which can construct a stable energy dissipation and free radical capture network, effectively suppressing irradiation-induced chain breakage and uneven cross-linking, and endowing the material with excellent irradiation stability and mechanical retention.

[0008] The polar structure of multidentate ligands can form interfacial adsorption with a small number of polar groups in EPDM rubber, improving the interfacial binding force of perovskite nanocrystals in the rubber matrix. This enables them to achieve uniform dispersion in the EPDM rubber matrix and enhances the interfacial interaction with polymer chains. Furthermore, they can form a multi-scale synergistic reinforcing network with reinforcing fillers, maintaining high tensile strength, elongation at break, and elasticity after irradiation, thus providing better dimensional stability and reliability of the rubber under high-irradiation environments. However, excessive multidentate ligand perovskite nanocrystal filling the rubber matrix can lead to agglomeration due to excessively high surface energy, which reduces its radiation resistance; therefore, its proportion should not exceed 10 parts.

[0009] Lead polyacrylate (PPA) is used as a radiation shielding material. The lead ions in PPA exhibit strong photoelectric effect and Compton scattering ability against gamma rays, forming a radiation-blocking layer within the EPDM rubber matrix to absorb radiation energy. Furthermore, when high-energy radiation induces the generation of active free radicals in the rubber matrix, the carboxyl groups of the PPA chains can capture these free radicals through coordination. Lead ions can then form stable coordination compounds with the free radicals, synergistically blocking and capturing them with the perovskite nanocrystals CsPbBr3, inhibiting chain crosslinking or cleavage reactions initiated by free radicals. Simultaneously, the PPA chains of PPA can entangle with the perovskite surface's multidentate ligands, and the lead ions in the PPA and perovskite nanocrystals can coordinate with the vulcanizing agent. This further enhances the bonding force between the perovskite nanocrystals, PPA, and the EPDM rubber matrix during vulcanization, preventing interfacial gaps that could lead to a decrease in the mechanical properties of the rubber material. However, if lead polyacrylate is in excess, its lead ions will compete with the coordination groups of the polydentate ligand perovskite nanocrystals for coordination, destroying the surface modification layer of the perovskite nanocrystals and causing the perovskite nanocrystals to agglomerate. Therefore, this application controls its amount to no more than 5 parts.

[0010] Since irradiation energy often leads to temperature increases, and both lead polyacrylate and multidentate ligand perovskite nanocrystals exhibit instability at high temperatures, this application introduces polyphenylvinylsilane. The Si-O-Si bonds in polyphenylvinylsilane have high bond energies, making them less susceptible to damage from radiation energy. The benzene ring possesses thermal stability, allowing it to act as a thermal barrier, absorbing and dispersing heat, reducing the direct impact of high temperatures under irradiation on lead polyacrylate and multidentate ligand perovskite nanocrystals, thereby improving their high-temperature stability and enhancing the radiation resistance and long-term operating temperature of the rubber system.

[0011] The rigid phenyl structure of polyphenylvinylsilanes can form a rigid network, resisting external deformation and improving the tensile strength and hardness of the system. Furthermore, the phenyl structure in the polyphenylvinylsilane molecule has strong free radical stabilizing and trapping capabilities, which can inhibit the spread of free radical chain reactions during irradiation, thereby further improving the radiation resistance of EPDM rubber. However, due to the rigid polyphenyl ring structure of polyphenylvinylsilanes, excessive addition can cause the rubber material to become hard and brittle; therefore, its content should not exceed 6 parts.

[0012] Optionally, the preparation of the polyphenylvinylsilane includes the following steps: S01 is weighed in a weight ratio of 1:0.8:(3-4) with dibenzyl ketone, 1,4-bis(phenyloxoyl)benzene and anhydrous ethanol. The mixture is heated under an inert atmosphere and refluxed. A potassium hydroxide ethanol solution accounting for 10-15% of the total weight of the solution is added dropwise. The reaction is carried out for 15-30 min. After the reaction is completed, the mixture is cooled, filtered, and the solid is collected. After purification, the intermediate product bis(tetraphenylcyclopentadienone) is obtained. SO2 is prepared by weighing bis(tetraphenylcyclopentadienone) and tetramethyldivinyldisiloxane at a weight ratio of 1:(2-4), passing an inert gas through the mixture, and reacting at 210-230℃ for 12-36 h. After the reaction is complete, unreacted monomers are removed to obtain the final product.

[0013] Specifically, the specific reaction in step S01 is as follows:

[0014] Specifically, the reaction in step S02 is as follows:

[0015] Optionally, the weight ratio of the multidentate ligand perovskite nanocrystals to polyphenylvinylsilane is (0.5-2):1.

[0016] Within this weight ratio range, polyphenylvinylsilane can form a stable thermal protection and rigid support structure around perovskite nanocrystals. Without significantly reducing the flexibility of the rubber, it can effectively alleviate the adverse effects of radiation-induced heating on the structural stability of perovskite nanocrystals, while ensuring that the energy absorption and carrier trapping capabilities of perovskite nanocrystals are fully utilized, thereby achieving a synergistic improvement in radiation resistance and mechanical properties.

[0017] Optionally, the weight ratio of the multidentate ligand perovskite nanocrystals to lead polyacrylate is (0.5-2):1.

[0018] Within this weight ratio range, a stable synergistic relationship can be formed between lead ions in lead polyacrylate and the coordination structure on the surface of perovskite nanocrystals with multidentate ligands. This effectively exerts the functions of radiation shielding and free radical capture while avoiding coordination competition and perovskite nanocrystal aggregation caused by excessive lead ions, thereby ensuring the interfacial stability and long-term radiation resistance of the system.

[0019] Preferably, the weight ratio of the multidentate ligand perovskite nanocrystals to lead polyacrylate is (0.5-1):1.

[0020] Optionally, the preparation method of the multidentate ligand perovskite nanocrystals CsPbBr3 is as follows: Preparation of S1 multidentate ligand poly(maleic anhydride-co-1-octadecene): Maleic anhydride and octadecene are dissolved in toluene, benzoyl peroxide is added as an initiator, and the mixture is heated to 95-120 °C for 4-10 h. After the reaction is completed, the mixture is dried under vacuum to obtain the product. Preparation of S2 cesium oleate precursor: Cesium carbonate, oleic acid and octadecene are added to a three-necked flask and heated until the cesium carbonate is completely dissolved. Synthesis of S3 perovskite nanocrystals: Lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine and octadecene were added to a three-necked flask, heated to 160°C, and a cesium oleate solution preheated to 100°C was quickly injected. After maintaining the reaction for 10 seconds, the flask was quickly immersed in an ice-water bath to cool to room temperature to obtain the crude product. S4 purification: Add an equal volume of ethyl acetate to the crude product and centrifuge to obtain polydentate ligand perovskite nanocrystals.

[0021] Multidentate ligand poly(maleic anhydride-co-1-octadecene) can react with Pb on the surface of perovskite nanocrystals 2+ Multi-point coordination effectively passivates surface defects and improves the structural integrity and thermal stability of nanocrystals; at the same time, its long-chain alkyl structure enhances its compatibility with the rubber matrix, making the nanocrystals more uniformly dispersed in EPDM, thereby ensuring that its radiation protection capability is effectively exerted inside the rubber.

[0022] Optionally, the weight ratio of maleic anhydride, octadecene, and toluene in step S1 is 1:(1.5-3):(2-5).

[0023] Preferably, the weight ratio of maleic anhydride, octadecene, and toluene in step S1 is 1:(2-2.5):(2-4).

[0024] Optionally, the amount of benzoyl peroxide used is 2-6% of the total weight of maleic anhydride and octadecene.

[0025] Preferably, the amount of benzoyl peroxide used is 2-4% of the total weight of maleic anhydride and octadecene.

[0026] Optionally, the weight ratio of cesium carbonate, oleic acid, and octadecene maleic anhydride in step S2 is 1:(0.1-0.6):(20-50).

[0027] Preferably, the weight ratio of cesium carbonate, oleic acid, and octadecene maleic anhydride in step S2 is 1:(0.2-0.4):(35-45).

[0028] Optionally, the weight ratio of lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine, and octadecene in step S3 is 1:(0.5-2):(0.1-1):(40-80).

[0029] Preferably, the weight ratio of lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine, and octadecene in step S3 is 1:(0.5-1):(0.1-0.8):(50-70).

[0030] Optionally, the reinforcing filler is at least one of carbon black and silica.

[0031] Optionally, the reinforcing filler is 45-65 parts of carbon black.

[0032] Preferably, the reinforcing filler is 60 parts of N 550 carbon black.

[0033] Optionally, the vulcanizing agent is at least one of dicumyl peroxide and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0034] Preferably, the vulcanizing agent is dicumyl peroxide.

[0035] Optionally, the vulcanizing agent is 2-3 parts.

[0036] Optionally, the crosslinking agent is at least one of N,N'-m-phenylenebismaleimide, triallyl isocyanurate, and trimethylolpropane trimethacrylate.

[0037] Preferably, the crosslinking agent is triallyl isocyanurate.

[0038] Optionally, the crosslinking agent is 2-3 parts.

[0039] According to a second aspect of this application, this application provides a method for preparing radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals as described in any of the above claims, comprising the following steps: (1) After mixing EPDM rubber and reinforcing filler evenly, add perovskite nanocrystal CsPbBr3, lead polyacrylate, polyphenyl vinyl silane, vulcanizing agent and crosslinking agent in sequence and mix evenly to obtain compound rubber. When the crosslinking agent is 0 parts, no crosslinking agent is added. (2) The compound rubber is vulcanized and molded to obtain the final product.

[0040] Optionally, the vulcanization conditions in step (2) are: vulcanization temperature of 150-170℃ and vulcanization time of 8-15min.

[0041] The beneficial effects of this application include, but are not limited to: 1. The radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals according to this application has excellent radiation resistance, maintains good mechanical properties under irradiation environment, and has a longer service life.

[0042] 2. The radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals according to this application introduces multidentate ligand perovskite nanocrystals CsPbBr3 into the EPDM rubber matrix. By utilizing their excellent high-energy radiation absorption capacity and electron trapping characteristics, the generation of radiation-induced free radicals and chain scission reactions are effectively suppressed, thereby significantly improving the structural stability and mechanical retention of the rubber under high-energy irradiation environments such as γ-rays and electron beams, and extending the service life of the material.

[0043] 3. The radiation-resistant EPDM rubber based on perovskite nanocrystals according to this application uses multidentate ligands to modify the surface of perovskite nanocrystals, so that they can be uniformly dispersed in the EPDM rubber matrix and enhance the interfacial interaction with the polymer chain. This avoids the problem of poor interfacial compatibility and uneven dispersion of traditional inorganic fillers, which leads to a decrease in mechanical properties and maintains the flexibility and elasticity of the rubber.

[0044] 4. The radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals of this application improves the radiation resistance of the rubber material by synergistically blocking and capturing free radicals through lead polyacrylate and multidentate ligand perovskite nanocrystals CsPbBr3, thereby inhibiting chain crosslinking or cleavage reactions initiated by free radicals.

[0045] 5. According to the radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals of this application, polyphenyl vinylsilane is introduced. Through Si-O-Si bonds and benzene ring structure, the direct impact of high temperature under irradiation on lead polyacrylate and multidentate ligand perovskite nanocrystals is reduced, thereby improving the radiation resistance and long-term service temperature of the rubber system. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is the mass spectrum of bis(tetraphenylcyclopentadienone) prepared in Example 3 of the present invention.

[0047] Figure 2 The above is the 1H NMR spectrum of the polyphenylvinylsilane prepared in Example 3 of this invention. Detailed Implementation

[0048] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0049] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application were all purchased commercially.

[0050] Unless otherwise specified, the methods used in the embodiments and comparative examples of this application are conventional methods in the prior art.

[0051] Example 1 This embodiment relates to a radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals, which comprises the following raw materials by weight: 100 parts of EPDM rubber, 30 parts of reinforcing filler fumed silica, 0.5 parts of multidentate ligand perovskite nanocrystals CsPbBr3, 0.5 parts of lead polyacrylate, 0.5 parts of polyphenyl vinyl silane, and 1 part of vulcanizing agent dicumyl peroxide. The structural formula of the polyphenylvinylsilane is as follows: .

[0052] The preparation of polyphenylvinylsilane includes the following steps: S01 was weighed in a weight ratio of 1:0.8:3, including dibenzyl ketone (CAS: 102-04-5), 1,4-bis(phenyloxo)benzene (CAS: 3363-97-1), and anhydrous ethanol. The mixture was added to a reaction flask and heated under nitrogen atmosphere and refluxed. A potassium hydroxide ethanol solution (20wt% potassium hydroxide concentration) accounting for 10% of the total weight of the solution was added dropwise. After the addition was completed, the reaction was allowed to proceed for 15 min. After the reaction was completed, the mixture was cooled and the solid was collected by filtration. The solid was dissolved in dichloromethane and purified by recrystallization to obtain the intermediate product bis(tetraphenylcyclopentadienone). SO2 is weighed at a weight ratio of 1:2 for bis(tetraphenylcyclopentadienone) and tetramethyldivinyldisiloxane (CAS: 2627-95-4), added to a reaction vessel, and nitrogen gas is introduced. The reaction is carried out at 210℃ for 36 h. After the reaction is completed, the unreacted tetramethyldivinyldisiloxane is removed by vacuum distillation to obtain the final product.

[0053] The preparation of CsPbBr3 perovskite nanocrystals with multidentate ligands includes the following steps: Preparation of S1 multidentate ligand poly(maleic anhydride-co-1-octadecene): Maleic anhydride and octadecene were dissolved in toluene in a weight ratio of 1:1.5:2. Benzoyl peroxide, an initiator accounting for 3% of the total weight of maleic anhydride and octadecene, was added. The mixture was heated to 95°C and reacted for 10 h. After the reaction was completed, the mixture was dried under vacuum to obtain the product. Preparation of S2 cesium oleate precursor: Cesium carbonate, oleic acid and octadecene in a weight ratio of 1:0.1:20 were added to a three-necked flask and heated until the cesium carbonate was completely dissolved. Synthesis of S3 perovskite nanocrystals: Lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine and octadecene in a weight ratio of 1:0.5:0.1:40 were added to a three-necked flask, heated to 160°C, and a cesium oleate solution preheated to 100°C was rapidly injected. After maintaining the reaction for 10 seconds, the flask was quickly immersed in an ice-water bath to cool to room temperature to obtain the crude product. S4 purification: An equal volume of ethyl acetate was added to the crude product, and the mixture was centrifuged to obtain polydentate ligand perovskite nanocrystals. The preparation method of this radiation-resistant EPDM rubber includes the following steps: (1) After adding EPDM rubber and reinforcing filler to the internal mixer and mixing them evenly, add multidentate ligand perovskite nanocrystal CsPbBr3, lead polyacrylate, polyphenyl vinyl silane and vulcanizing agent in sequence and mix them evenly to obtain a compound. The rotor speed is set to 60 r / min and the initial temperature is 55℃. Mix until the torque of the internal mixer is stable and unchanged, and then discharge the compound. (2) Place the compounded rubber in a vacuum vulcanizing machine and vulcanize it at 150°C for 15 minutes to obtain radiation-resistant EPDM rubber.

[0054] Example 2 This embodiment relates to a radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals, which comprises the following raw materials by weight: 100 parts of EPDM rubber, 80 parts of reinforcing filler N330 carbon black, 10 parts of multidentate ligand perovskite nanocrystals CsPbBr3, 5 parts of lead polyacrylate, 6 parts of polyphenyl vinyl silane, 5 parts of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 4 parts of co-crosslinking agent N,N'-m-phenylenebismaleimide. The structural formula of the polyphenylvinylsilane is as follows: .

[0055] The preparation of polyphenylvinylsilane includes the following steps: S01: Dibenzyl ketone (CAS: 102-04-5), 1,4-bis(phenyloxo)benzene (CAS: 3363-97-1), and anhydrous ethanol were weighed in a weight ratio of 1:0.8:4 and added to a reaction flask. The mixture was heated to reflux under a nitrogen atmosphere. A potassium hydroxide ethanol solution (20 wt% potassium hydroxide concentration) accounting for 15% of the total weight of the solution was added dropwise. After the addition was completed, the reaction was allowed to proceed for 30 min. After the reaction was completed, the mixture was cooled and the solid was collected by filtration. The solid was dissolved in dichloromethane and purified by recrystallization to obtain the intermediate product bis(tetraphenylcyclopentadienone). SO2 is weighed at a weight ratio of 1:4 for bis(tetraphenylcyclopentadienone) and tetramethyldivinyldisiloxane (CAS:2627-95-4), added to a reaction vessel, and nitrogen gas is introduced. The reaction is carried out at 230℃ for 12 h. After the reaction is completed, the unreacted tetramethyldivinyldisiloxane is removed by vacuum distillation to obtain the final product.

[0056] The preparation of CsPbBr3 perovskite nanocrystals with multidentate ligands includes the following steps: Preparation of S1 multidentate ligand poly(maleic anhydride-co-1-octadecene): Maleic anhydride and octadecene were dissolved in toluene in a weight ratio of 1:3:5. Benzoyl peroxide, an initiator accounting for 6% of the total weight of maleic anhydride and octadecene, was added. The mixture was heated to 120°C and reacted for 4 hours. After the reaction was completed, the mixture was dried under vacuum to obtain the product. Preparation of S2 cesium oleate precursor: Cesium carbonate, oleic acid and octadecene in a weight ratio of 1:0.6:50 are added to a three-necked flask and heated until the cesium carbonate is completely dissolved. Synthesis of S3 perovskite nanocrystals: Lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine and octadecene in a weight ratio of 1:2:1:80 were added to a three-necked flask, heated to 160°C, and a cesium oleate solution preheated to 100°C was rapidly injected. After maintaining the reaction for 10 seconds, the flask was quickly immersed in an ice-water bath to cool to room temperature to obtain the crude product. S4 purification: Add an equal volume of ethyl acetate to the crude product and centrifuge to obtain polydentate ligand perovskite nanocrystals.

[0057] The preparation method of this radiation-resistant EPDM rubber includes the following steps: (1) After adding EPDM rubber and reinforcing filler to the internal mixer and mixing them evenly, add multidentate ligand perovskite nanocrystal CsPbBr3, lead polyacrylate, polyphenyl vinyl silane, vulcanizing agent and crosslinking agent in sequence and mix them evenly to obtain a compound. The rotor speed is set to 60 r / min and the initial temperature is 55℃. Mix until the torque of the internal mixer is stable and unchanged, and then discharge the compound. (2) Place the compounded rubber in a vacuum vulcanizing machine and vulcanize it at 170°C for 8 minutes to obtain radiation-resistant EPDM rubber.

[0058] Example 3 This embodiment relates to a radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals, which comprises the following raw materials by weight: 100 parts of EPDM rubber, 60 parts of reinforcing filler N550 carbon black, 2 parts of multidentate ligand perovskite nanocrystals CsPbBr3, 4 parts of lead polyacrylate, 4 parts of polyphenyl vinyl silane, 3 parts of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2 parts of crosslinking agent triallyl isocyanurate. The structural formula of the polyphenylvinylsilane is as follows: .

[0059] The preparation of polyphenylvinylsilane includes the following steps: S01: Dibenzyl ketone (CAS: 102-04-5), 1,4-bis(phenyloxo)benzene (CAS: 3363-97-1), and anhydrous ethanol were weighed in a weight ratio of 1:0.8:3.5 and added to a reaction flask. The mixture was heated under a nitrogen atmosphere, and a potassium hydroxide ethanol solution (20 wt% potassium hydroxide concentration) accounting for 13% of the total weight of the solution was added dropwise. After the addition was completed, the reaction was allowed to proceed for 25 min. After the reaction was completed, the mixture was cooled, and the solid was collected by filtration. The solid was dissolved in dichloromethane and purified by recrystallization to obtain the intermediate product bis(tetraphenylcyclopentadienone). SO2 is prepared by weighing bis(tetraphenylcyclopentadienone) and tetramethyldivinyldisiloxane (CAS: 2627-95-4) at a weight ratio of 1:3, adding them to a reaction vessel, introducing nitrogen gas, and reacting at 220℃ for 30 h. After the reaction is completed, the unreacted tetramethyldivinyldisiloxane is removed by vacuum distillation to obtain the final product.

[0060] The preparation of CsPbBr3 perovskite nanocrystals with multidentate ligands includes the following steps: Preparation of S1 multidentate ligand poly(maleic anhydride-co-1-octadecene): Maleic anhydride and octadecene were dissolved in toluene in a weight ratio of 1:2.5:4. Benzoyl peroxide, an initiator accounting for 4% of the total weight of maleic anhydride and octadecene, was added. The mixture was heated to 100°C and reacted for 10 h. After the reaction was completed, the mixture was dried under vacuum to obtain the product. Preparation of S2 cesium oleate precursor: Cesium carbonate, oleic acid and octadecene in a weight ratio of 1:0.4:45 were added to a three-necked flask and heated until the cesium carbonate was completely dissolved. Synthesis of S3 perovskite nanocrystals: Lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine and octadecene in a weight ratio of 1:1:0.8:50 were added to a three-necked flask, heated to 160°C, and a cesium oleate solution preheated to 100°C was rapidly injected. After maintaining the reaction for 10 seconds, the flask was quickly immersed in an ice-water bath to cool to room temperature to obtain the crude product. S4 purification: Add an equal volume of ethyl acetate to the crude product and centrifuge to obtain polydentate ligand perovskite nanocrystals.

[0061] The preparation method of this radiation-resistant EPDM rubber includes the following steps: (1) After adding EPDM rubber and reinforcing filler to the internal mixer and mixing them evenly, add multidentate ligand perovskite nanocrystal CsPbBr3, lead polyacrylate, polyphenyl vinyl silane, vulcanizing agent and crosslinking agent in sequence and mix them evenly to obtain a compound. The rotor speed is set to 60 r / min and the initial temperature is 55℃. Mix until the torque of the internal mixer is stable and unchanged, and then discharge the compound. (2) Place the compounded rubber in a vacuum vulcanizing machine and vulcanize it at 160°C for 15 minutes to obtain aging-resistant EPDM rubber.

[0062] Mass spectrometry analysis was performed on the bis(tetraphenylcyclopentadienone) obtained in Example 3 to obtain... Figure 1 ,Depend on Figure 1 The peaks at 691.26 and 713.24 in the mass spectrum indicate the successful synthesis of the product. Mass spectrometry and 1H NMR spectroscopy of the polyphenylvinylsilane yielded... Figure 2 ,Depend on Figure 2 The results showed that the characteristic peaks of hydrogen protons on the benzene ring were located at chemical shifts of 6.2–7.6 ppm, the characteristic peaks of hydrogen protons on -CH=CH2 were located at chemical shifts of 5.8–6.0 ppm, and the characteristic peaks of hydrogen protons on -CH3 were located at chemical shift of 0 ppm. The integral area ratio of hydrogen protons on -CH3 and -CH=CH2 was approximately 4:1, indicating the successful synthesis of polyphenylvinylsilane.

[0063] Example 4 This embodiment relates to a radiation-resistant EPDM rubber based on multidentate ligand perovskite nanocrystals, which comprises the following raw materials by weight: 100 parts of EPDM rubber, 45 parts of reinforcing filler N550 carbon black, 10 parts of multidentate ligand perovskite nanocrystals CsPbBr3, 3 parts of lead polyacrylate, 5 parts of polyphenyl vinyl silane, 2 parts of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of co-crosslinking agent trimethylolpropane trimethacrylate. The structural formula of the polyphenylvinylsilane is as follows: .

[0064] The preparation of polyphenylvinylsilane includes the following steps: S01: Dibenzyl ketone (CAS: 102-04-5), 1,4-bis(phenyloxo)benzene (CAS: 3363-97-1), and anhydrous ethanol were weighed in a weight ratio of 1:0.8:3.8 and added to a reaction flask. The mixture was heated to reflux under a nitrogen atmosphere. A potassium hydroxide ethanol solution (20 wt% potassium hydroxide concentration) accounting for 14% of the total weight of the solution was added dropwise. After the addition was completed, the reaction was allowed to proceed for 20 min. After the reaction was completed, the mixture was cooled and the solid was collected by filtration. The solid was dissolved in dichloromethane and purified by recrystallization to obtain the intermediate product bis(tetraphenylcyclopentadienone). SO2 is weighed at a weight ratio of 1:3.5 for bis(tetraphenylcyclopentadienone) and tetramethyldivinyldisiloxane (CAS:2627-95-4), added to a reaction vessel, and nitrogen gas is introduced. The reaction is carried out at 225°C for 36 h. After the reaction is completed, the unreacted tetramethyldivinyldisiloxane is removed by vacuum distillation to obtain the final product.

[0065] The preparation of CsPbBr3 perovskite nanocrystals with multidentate ligands includes the following steps: Preparation of S1 multidentate ligand poly(maleic anhydride-co-1-octadecene): Maleic anhydride and octadecene were dissolved in toluene in a weight ratio of 1:2:3. Benzoyl peroxide, an initiator accounting for 5% of the total weight of maleic anhydride and octadecene, was added. The mixture was heated to 120°C and reacted for 6 hours. After the reaction was completed, the mixture was dried under vacuum to obtain the product. Preparation of S2 cesium oleate precursor: Cesium carbonate, oleic acid and octadecene in a weight ratio of 1:0.2:35 were added to a three-necked flask and heated until the cesium carbonate was completely dissolved. Synthesis of S3 perovskite nanocrystals: Lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine and octadecene in a weight ratio of 1:1.5:0.5:70 were added to a three-necked flask, heated to 160°C, and a cesium oleate solution preheated to 100°C was rapidly injected. After maintaining the reaction for 10 seconds, the flask was quickly immersed in an ice-water bath to cool to room temperature to obtain the crude product. S4 purification: Add an equal volume of ethyl acetate to the crude product and centrifuge to obtain polydentate ligand perovskite nanocrystals.

[0066] The preparation method of this radiation-resistant EPDM rubber includes the following steps: (1) Add EPDM rubber and reinforcing filler to the internal mixer and mix evenly. Then add perovskite nanocrystals with multidentate ligands, lead polyacrylate, polyphenyl vinyl silane, vulcanizing agent and crosslinking agent in sequence and mix evenly to obtain a compound. The rotor speed is set to 60 r / min and the initial temperature is 55℃. Mix until the torque of the internal mixer is stable and unchanged, and then discharge the compound. (2) Place the compounded rubber in a vacuum vulcanizing machine and vulcanize it at 165°C for 15 minutes to obtain aging-resistant EPDM rubber.

[0067] Example 5 The difference between Example 5 and Example 3 is that the amount of multidentate ligand perovskite nanocrystals CsPbBr3 is 9 parts, while the rest are the same.

[0068] Example 6 The difference between Example 6 and Example 3 is that the amount of lead polyacrylate is 5 parts, while the rest are the same.

[0069] Example 7 The difference between Example 7 and Example 3 is that the amount of polyphenyl vinylsilane is 0.8 parts, and the rest are the same.

[0070] Example 8 The difference between Example 8 and Example 3 is that citric acid is used instead of polydentate ligand poly(maleic anhydride-co-1-octadecene) in step S3, and step S1 is omitted; all other steps are the same.

[0071] Comparative Example 1 The difference between Comparative Example 1 and Example 3 is that the amount of multidentate ligand perovskite nanocrystals CsPbBr3 is 11 parts, while the rest are the same.

[0072] Comparative Example 2 The difference between Comparative Example 2 and Example 3 is that the multidentate ligand perovskite nanocrystals CsPbBr3 are not added, and the preparation steps of multidentate ligand perovskite nanocrystals CsPbBr3 are not included; all other steps are the same.

[0073] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the amount of lead polyacrylate is 6 parts, while the rest are the same.

[0074] Comparative Example 4 The difference between Comparative Example 4 and Example 3 is that polyphenylvinylsilane is not added, but all other aspects are the same.

[0075] Comparative Example 5 The difference between Comparative Example 5 and Example 3 is that the amount of polyphenyl vinylsilane is 6.5 parts, and the rest are the same.

[0076] Comparative Example 6 The difference between Comparative Example 6 and Example 3 is that phenyltriethoxysilane (CAS: 780-69-8) was used instead of polyphenylvinylsilane, and all other aspects were the same.

[0077] Comparative Example 7 The difference between Comparative Example 7 and Example 3 is that CsSnBr3 is used instead of CsPbBr3, and stannous bromide is used instead of lead bromide in step S3. All other aspects are the same.

[0078] Comparative Example 8 The difference between Comparative Example 8 and Example 3 is that CsPbI3 is used instead of CsPbBr3, and lead iodide is used instead of lead bromide in step S3. All other aspects are the same.

[0079] Comparative Example 9 The difference between Comparative Example 9 and Example 3 is that perovskite nanocrystals CsPbBr3 are used instead of the multidentate ligand perovskite nanocrystals CsPbBr3, and the multidentate ligand poly(maleic anhydride-co-1-octadecene) in step S3 is replaced with oleic acid, while the rest are the same.

[0080] Test Example 1 The EPDM rubbers prepared according to the above examples were subjected to mechanical property tests. The tests were conducted on an electronic universal testing machine at a speed of 500 mm / min, in accordance with the national standard GB / T-528—2009. Each sample underwent three parallel experiments, and the average value was taken. The test results are shown in Table 1.

[0081] Table 1

[0082] As shown in Table 1, all embodiments exhibited good mechanical properties under non-irradiation conditions, with tensile strength ranging from 15.4 to 16.8 MPa and elongation at break ranging from 323 to 350%. This indicates that the introduction of multidentate ligand perovskite nanocrystals, lead polyacrylate, and polyphenyl vinyl silane within a reasonable ratio range did not have a significant adverse effect on the intrinsic mechanical properties of EPDM rubber.

[0083] Among them, Example 3 achieved the highest tensile strength and elongation at break, reaching 16.8 MPa and 350%, respectively. This indicates that under this formulation, a relatively reasonable synergistic reinforcement system was formed between the multidentate ligand perovskite nanocrystals, lead polyacrylate, and polyphenylvinylsilane. On the one hand, the multidentate ligand perovskite nanocrystals, under the modification of the multidentate ligands, can be uniformly dispersed in the EPDM matrix and form good interfacial interactions with the rubber molecular chains; on the other hand, the rigid phenyl structure of the polyphenylvinylsilane participates in network construction during vulcanization, which helps to improve the load-bearing capacity of the system, thereby enabling the material to obtain high tensile strength while maintaining high elongation at break.

[0084] Comparative examples 5-7 show that when the amounts of the multidentate ligand perovskite nanocrystals, polyphenylvinylsilane, or lead polyacrylate deviate from the specified ratio range, the tensile strength and elongation at break of the material all decrease to varying degrees. This indicates that the above three components must be maintained in a reasonable ratio in the rubber system; excessively high or low additions may lead to interfacial compatibility or network structure imbalance, thereby affecting mechanical properties.

[0085] In addition, the amount of multidentate ligand perovskite nanocrystals in Comparative Example 1 exceeded 10 parts, the amount of lead polyacrylate in Comparative Example 3 exceeded 5 parts, and the amount of polyphenyl vinyl silane in Comparative Example 5 exceeded 6 parts. All of these resulted in a significant decrease in tensile strength and elongation at break, indicating that excessive addition can cause filler agglomeration or excessive network rigidity, thereby weakening the overall mechanical properties of the rubber material.

[0086] Test Example 2 The EPDM rubber samples prepared in the above examples were irradiated with 60Co γ-rays at room temperature, with a cumulative irradiation dose of 1000 kGy. Mechanical properties were then tested according to national standard GB / T-528—2009 on an electronic universal testing machine at a speed of 500 mm / min. Each sample underwent three parallel experiments, and the average value was taken. The test results are shown in Table 1, where the change rate of tensile strength before and after irradiation is calculated as (tensile strength after irradiation - tensile strength before irradiation) / tensile strength before irradiation *%, and the change rate of elongation at break before and after irradiation is calculated as (elongation at break after irradiation - elongation at break before irradiation) / elongation at break before irradiation *%.

[0087] Table 2

[0088] As shown in Table 2, after 1000 kGy γ-ray irradiation, the change rates of tensile strength and elongation at break of each embodiment were significantly smaller than those of the comparative embodiments, indicating that the rubber system described in this application has better mechanical property retention under high-dose irradiation conditions.

[0089] Among them, the tensile strength change rate of Example 3 was only -8.40%, and the elongation at break change rate was -30.56%, which was the smallest attenuation among all samples. This indicates that the multidentate ligand perovskite nanocrystals, lead polyacrylate, and polyphenylvinylsilane can form a stable synergistic protective system under this ratio, effectively suppressing radiation-induced molecular chain breakage and excessive cross-linking.

[0090] In comparison, Comparative Example 2, without the addition of multidentate ligand perovskite nanocrystals, showed the most significant performance degradation, with tensile strength and elongation at break decreasing by 31.35% and 58.65%, respectively. This indicates that relying solely on reinforcing fillers and sulfurized networks is insufficient to effectively resist the damage to the EPDM molecular chain structure caused by high-energy irradiation.

[0091] In Comparative Example 4, without the addition of polyphenylvinylsilane, the rate of change of tensile strength and the rate of change of elongation at break were significantly higher than those in Example 3. This indicates that the thermal effect generated during irradiation exacerbates the instability of lead polyacrylate and perovskite nanocrystals, while the thermal barrier and rigid network structure formed by polyphenylvinylsilane play an important role in mitigating irradiation-induced temperature rise.

[0092] In Comparative Example 6, replacing polyphenylvinylsilane with phenyltriethoxysilane significantly increased the performance degradation after irradiation, indicating that the unique rigid polyphenyl ring structure and the ability of vinyl groups to participate in crosslinking in polyphenylvinylsilane play an irreplaceable role in constructing a stable radiation-resistant network structure.

[0093] In Comparative Examples 7 and 8, CsSnBr3 and CsPbI3 were used to replace CsPbBr3, respectively. The rate of change in their mechanical properties was significantly higher than that in Example 3. This indicates that the perovskite composition and halogen type have a significant impact on its radiation energy absorption, carrier trapping ability, and structural stability. Furthermore, the CsPbBr3 modified with multidentate ligands exhibits superior radiation resistance in this system. In summary, this application, through the synergistic effect of multidentate ligand perovskite nanocrystals, lead polyacrylate, and polyphenylvinylsilane, can effectively slow down the degradation of the mechanical properties of EPDM rubber under high-dose gamma-ray irradiation, and significantly improve the material's radiation resistance and long-term service reliability.

[0094] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, this application is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope of this application should be within the protection scope of this application.

Claims

1. A radiation tolerant ethylene propylene diene rubber based on a multi-dentate ligand perovskite nanocrystal, characterized in that, By weight parts, including the following components: ternary ethylene propylene rubber 100 parts, reinforcing filler 30-80 parts, polydentate ligand perovskite nanocrystals CsPbBr30.5-10 parts, lead polyacrylate 0.5-5 parts, polyphenyl vinyl silane 0.5-6 parts, vulcanizing agent 1-5 parts, auxiliary crosslinking agent 0-4 parts; The structure of the polyphenyl vinyl silane is as follows: 。 2. The irradiation tolerant EPDM terpolymer based on multi-dentate ligand perovskite nanocrystals of claim 1, wherein, The preparation of the polyphenyl vinyl silane comprises the following steps: S01 Take dibenzyl ketone, 1,4-bis(phenyldiacetyl) benzene and anhydrous ethanol according to the weight ratio of 1:0.8:(3-4), heat and reflux under inert gas atmosphere, add 10-15% of potassium hydroxide ethanol solution based on the total weight of the solution, react for 15-30 min, cool and filter after the reaction is completed, and collect the solid, to obtain the intermediate product bis-tetraphenyl cyclopentadienone after purification; S02 Take bis-tetraphenyl cyclopentadienone and tetramethyl divinyl disiloxane according to the weight ratio of 1:(2-4), introduce inert gas, and react at 210-230℃ for 12-36 h, to obtain the product after removing the unreacted monomer after the reaction is completed.

3. The irradiation tolerant EPDM terpolymer based on multi-dentate ligand perovskite nanocrystals of claim 1, wherein, The weight ratio of the polydentate ligand perovskite nanocrystals and the polyphenyl vinyl silane is (0.5-2):

1.

4. The irradiation tolerant EPDM terpolymer based on multi-dentate ligand perovskite nanocrystals of claim 1, wherein, The weight ratio of the polydentate ligand perovskite nanocrystals and the lead polyacrylate is (0.5-2):

1.

5. The irradiation tolerant EPDM terpolymer based on multi-dentate ligand perovskite nanocrystals of claim 1, wherein, The preparation method of the polydentate ligand perovskite nanocrystals CsPbBr3 is as follows: S1 Preparation of polydentate ligand poly(maleic anhydride-co-1-octadecene): dissolve maleic anhydride and octadecene in a solvent, add initiator dibenzoyl peroxide, heat to 95-120℃ and react for 4-10 h, and dry under vacuum after the reaction is completed; S2 Preparation of cesium oleate precursor: add cesium carbonate, oleic acid and octadecene into a three-necked flask, and heat to completely dissolve the cesium carbonate, to obtain the product; S3 Synthesis of perovskite nanocrystals: add lead bromide, polydentate ligand poly(maleic anhydride-co-1-octadecene), oleylamine and octadecene into a three-necked flask, heat to 160℃, quickly inject the preheated cesium oleate solution to 100℃, maintain the reaction for 10 s, quickly immerse the flask into ice water bath to cool to room temperature, and obtain the crude product; S4 Purification: add equal volume of ethyl acetate into the crude product, and centrifuge, to obtain the polydentate ligand perovskite nanocrystals.

6. The irradiation tolerant EPDM terpolymer based on multi-dentate ligand perovskite nanocrystals of claim 5, wherein, The weight ratio of the maleic anhydride, octadecene and toluene in step S1 is 1:(1.5-3):(2-5); The amount of the dibenzoyl peroxide is 2-6% of the total weight of the maleic anhydride and octadecene; Preferably, the weight ratio of the maleic anhydride, octadecene and toluene is 1:(2-2.5):(3-4); Preferably, the amount of the dibenzoyl peroxide is 2-4% of the total weight of the maleic anhydride and octadecene.

7. The irradiation tolerant EPDM terpolymer based on multi-dentate ligand perovskite nanocrystals of claim 5, wherein, The weight ratio of the cesium carbonate, oleic acid and octadecene in step S2 is 1:(0.1-0.6):(20-50); Preferably, the weight ratio of the cesium carbonate, oleic acid and octadecene is 1:(0.2-0.4):(35-45).

8. The irradiation tolerant EPDM terpolymer based on multi-dentate ligand perovskite nanocrystals of claim 5, wherein, The weight ratio of the lead bromide, the polydentate ligand poly(maleic anhydride-co-1-octadecene), the oleylamine and the octadecene in step S3 is 1:(0.5-2):(0.1-1):(40-80); Preferably, the weight ratio of the lead bromide, the polydentate ligand poly(maleic anhydride-co-1-octadecene), the oleylamine and the octadecene is 1:(0.5-1):(0.1-0.8):(50-70).

9. The method of producing a radiation tolerant terpolymer ethylene propylene rubber based on multidentate ligand perovskite nanocrystals according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: (1) uniformly mixing the ethylene-propylene-diene rubber and the reinforcing filler, then adding the polydentate ligand perovskite nanocrystal, the lead polyacrylate, the polyphenyl vinyl silane, the vulcanizing agent and the auxiliary crosslinking agent in sequence, uniformly dispersing and mixing to obtain a mixed rubber, and when the auxiliary crosslinking agent is 0 part, no auxiliary crosslinking agent is added; (2) vulcanizing and forming the mixed rubber to obtain the product.

10. The method of claim 9, wherein the method is characterized by, The vulcanization condition in step (2) is that the vulcanization temperature is 150-170℃ and the vulcanization time is 8-15 min.

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