An oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber and its preparation and application

Abstract

This invention provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, its preparation method, and its applications. The preparation method uses acrylonitrile, butadiene, and isoprene as monomers, employs a low-temperature emulsion polymerization method, and involves the introduction of fluorinated monomer copolymerization, multi-stage addition of butadiene and / or isoprene, and the addition of a molecular weight regulator to prepare an acrylonitrile-butadiene-isoprene rubber with high fluorinated bound nitrile content. The oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber provided by this invention exhibits excellent oil and solvent resistance, heat resistance, fatigue resistance, and excellent mechanical and processing properties. It can be used in petrochemical and other fields where high comprehensive performance requirements such as oil resistance and mechanical properties are necessary. For example, it can be used as a rubber diaphragm in diaphragm pumps, extending the service life of the diaphragm, thereby reducing costs and improving equipment efficiency.

Description

Technical Field

[0001] This invention relates to an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, its preparation method, and its application. Specifically, it relates to the preparation of modified nitrile rubber (acrylonitrile-butadiene-isoprene rubber) using isoprene monomer via low-temperature emulsion polymerization, belonging to the technical field of nitrile rubber and its preparation. Background Technology

[0002] Diaphragm pumps are a new type of conveying machinery capable of transporting various corrosive liquids, liquids containing particles, highly concentrated, flammable, and highly toxic liquids. Due to their small footprint, ease of movement, lack of foundation requirements, simple and quick installation, and economic practicality, they are widely used in industries such as petrochemicals, metallurgy, and water treatment. The rubber diaphragm is a crucial component in the two-position, two-way valve of a diaphragm pump, used to seal off air. During the valve's opening and closing process, the diaphragm reciprocates with the valve push rod (valve core), isolating air and the transported liquid (oil) into two different closed chambers. Its performance directly affects the diaphragm pump's application range and lifespan. For the transportation of oily liquids in the petrochemical field, the rubber diaphragm typically needs to possess excellent oil resistance, fatigue resistance, and mechanical properties, with minimal hardness change within the operating temperature range, and the rubber compound having good processing properties.

[0003] Rubber types suitable for use as rubber diaphragms include nitrile rubber (NBR), hydrogenated NBR, fluororubber, and acrylic rubber. Among them, NBR exhibits superior oil resistance, cold resistance balance, and chemical stability compared to the chlorine and ester groups in the functional groups of other oil-resistant rubbers. However, the presence of double bonds in its molecule results in poor aging resistance. Hydrogenated NBR can be produced by selectively hydrogenating the double bonds in the NBR backbone, resulting in superior strength, oil resistance, aging resistance, and low-temperature resistance. It is increasingly widely used in the automotive, oilfield, and military industries. However, the production process of hydrogenated NBR is complex, and its price is higher than that of general-purpose NBR, which limits its widespread application to some extent. Acrylic rubber holds a significant position among oil-resistant rubbers, exhibiting excellent balance in oil resistance, heat resistance, and ozone resistance. However, its resistance to water swelling, fuel oil, and alkali is poor. Fluororubber possesses unparalleled high-temperature resistance, chemical resistance, and aging resistance compared to other rubbers. In terms of oil resistance and heat resistance, no other rubber type currently can match fluororubber. Although fluororubber, hydrogenated nitrile rubber, and acrylate rubber outperform nitrile rubber in some aspects, nitrile rubber still holds a certain advantage in the production of rubber diaphragms due to its overall balance of cost, processing performance, oil resistance, and heat and cold resistance. However, in the petrochemical industry, general-purpose nitrile rubber diaphragms struggle to meet the comprehensive requirements for oil resistance, fuel oil resistance, solvent resistance, tensile strength, and fatigue resistance. Furthermore, since diaphragms are thin-sheet rubber products, the rubber compound must possess excellent processing properties.

[0004] To address the comprehensive requirements of rubber diaphragms for oil resistance, high strength, and other properties, many nitrile butadiene rubber (NBR) products and their compositions with oil resistance or high strength have been developed in this field. For example, Chinese patent application CN103819762A discloses a high-strength, high-oil-resistant NBR composition, the preparation method of which includes: adding liquid-phase acrylonitrile monomer to NBR, and polymerizing acrylonitrile into polyacrylonitrile during the vulcanization process of NBR to obtain a polyacrylonitrile-NBR composition with good oil resistance and mechanical properties. However, this method relies on physical blending, making it difficult to achieve uniform dispersion of acrylonitrile block polymers. Furthermore, acrylonitrile is a toxic and harmful chemical, and the acrylonitrile monomer volatilized during the mixing process poses a significant health hazard. Additionally, this preparation method is unfavorable for preparing sheet-like rubber products. Gu Wenzheng et al. (Gu Wenzheng, Zhang Chunqing, Li Yang, et al. Synthesis of acrylonitrile-butadiene-isoprene terpolymer [J]. Synthetic Rubber Industry, 2012(02):21-24.) prepared acrylonitrile-butadiene-isoprene rubber by low-temperature emulsion polymerization, which improved the mechanical properties of nitrile rubber. However, since butadiene and isoprene were not added during the preparation of the terpolymer, the acrylonitrile content in the obtained terpolymer was low, only below 40%, which was difficult to meet the requirements of rubber diaphragms for high oil resistance and fuel oil resistance.

[0005] The acrylonitrile-butadiene-isoprene rubber prepared by the above-mentioned existing technologies has a low acrylonitrile content, which cannot meet the requirements for high oil and solvent resistance. In addition, the nitrile rubber and its compositions with high bound acrylonitrile content prepared by existing technologies usually have uneven distribution of nitrile chain segments, low mechanical properties, and are difficult to prepare into thin sheet rubber products.

[0006] Therefore, providing a novel oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, its preparation method, and its application have become urgent technical problems to be solved in this field. Summary of the Invention

[0007] To address the aforementioned shortcomings and deficiencies, one objective of this invention is to provide a method for preparing an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber.

[0008] Another object of the present invention is to provide an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by the preparation method described above.

[0009] Another object of the present invention is to provide a rubber diaphragm made from the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber described above.

[0010] Another object of the present invention is to provide a diaphragm pump comprising the rubber diaphragm described above.

[0011] To achieve the above objectives, on the one hand, the present invention provides a method for preparing an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, wherein the preparation method includes:

[0012] Based on a total weight of 100 parts for acrylonitrile, butadiene, and isoprene, add 220–295 parts of deionized water, 1.5–10.0 parts of emulsifier, 0.001–0.5 parts of pH buffer, 0.0005–0.2 parts of first reducing agent, 0.0004–0.2 parts of second reducing agent, 0.0003–0.4 parts of chelating agent, 0.1–1.5 parts of molecular weight regulator, 39–51 parts of acrylonitrile, 15–41 parts of isoprene, and 0.01–0.1 parts of oxygen scavenger to the polymerization reactor.

[0013] After nitrogen purging, 15-41 parts of butadiene are added and pre-emulsified, followed by 0.005-0.5 parts of organic hydrogen peroxide oxidant, so that the three monomers acrylonitrile, butadiene and isoprene can undergo copolymerization reaction at a polymerization temperature of 3-15℃.

[0014] When the conversion rates of acrylonitrile, butadiene, and isoprene reach 25-30%, butadiene is added. When the monomer conversion rate reaches 40-45%, isoprene, fluorinated monomers, and emulsifiers are added. When the monomer conversion rate reaches 55-65%, butadiene and isoprene are added again. When the monomer conversion rate reaches 35-65%, 0.01-0.5 parts of molecular weight regulator are added. When the monomer conversion rate reaches 78-83%, 0.1-1 parts of terminator are added to terminate the copolymerization reaction, resulting in oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber.

[0015] In a specific embodiment of the preparation method described above in this invention, based on a total weight of 100 parts of acrylonitrile, butadiene, and isoprene, 220-295 parts of deionized water, 1.5-10.0 parts of emulsifier, 0.001-0.5 parts of pH buffer, 0.0005-0.2 parts of first reducing agent, 0.0004-0.2 parts of second reducing agent, 0.0003-0.4 parts of chelating agent, 0.1-1.5 parts of molecular weight regulator, 39-51 parts of acrylonitrile, 15-41 parts of isoprene, and 0.01-0.1 parts of oxygen scavenger are added sequentially to the polymerization reactor.

[0016] Alternatively, based on a total weight of 100 parts of acrylonitrile, butadiene, and isoprene, add sequentially to the polymerization reactor 220–295 parts of deionized water, 1.5–10.0 parts of emulsifier, 0.001–0.5 parts of pH buffer, 0.0004–0.2 parts of secondary reducing agent, 0.0005–0.2 parts of primary reducing agent, 0.0003–0.4 parts of chelating agent, 0.1–1.5 parts of molecular weight regulator, 39–51 parts of acrylonitrile, 15–41 parts of isoprene, and 0.01–0.1 parts of oxygen scavenger.

[0017] In a specific embodiment of the preparation method described above in this invention, when the conversion rates of acrylonitrile, butadiene, and isoprene reach 25-30%, the amount of butadiene added is 1-8 parts; when the monomer conversion rate reaches 40-45%, the amount of isoprene added is 1-8 parts; and when the monomer conversion rate reaches 55-65%, the amounts of butadiene and isoprene added again are 1-8 parts each.

[0018] In one specific embodiment of the preparation method described above in this invention, the molecular weight regulator is added simultaneously with isoprene, or simultaneously with butadiene and isoprene.

[0019] In one specific embodiment of the preparation method described above in this invention, a molecular weight regulator is added when the monomer conversion rate reaches 40-45%.

[0020] The molecular weight regulator described in this invention is not particularly limited. As a specific embodiment of the preparation method described above, the molecular weight regulator includes one or a combination of several of tert-dodecyl mercaptan, n-dodecyl mercaptan, and dithiodiisopropyl xanthate.

[0021] As a specific embodiment of the preparation method described above in this invention, the fluorinated monomer is a fluorinated fatty acid ester monomer that can copolymerize with butadiene, acrylonitrile, and isoprene, including one of trifluoroethyl methacrylate, hexafluorobutyl methacrylate, or dodecafluoroheptyl methacrylate.

[0022] In one specific embodiment of the preparation method described above in this invention, the amount of the fluorinated monomer used is 0.1 to 5.0 parts.

[0023] In one specific embodiment of the preparation method described above in this invention, the amount of the fluorinated monomer used is 1.0 to 3.0 parts.

[0024] In one specific embodiment of the preparation method described above in this invention, when the monomer conversion rate reaches 40-45%, the amount of emulsifier added is 1.0-6.0 parts.

[0025] The emulsifier described in this invention is not particularly limited; any emulsifier that can be used in synthetic rubber can be used. As a specific embodiment of the preparation method described above, the emulsifier includes one or a combination of several of the following: sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, dispersant N, potassium synthetic fatty acid, potassium oleate, and potassium disproportionated rosinate.

[0026] The pH buffer described in this invention is not particularly limited. As a specific embodiment of the preparation method described above, the pH buffer includes sodium carbonate or sodium acetate.

[0027] The initiation system used in this invention is a redox system, and the reducing agent is not particularly limited. As a specific embodiment of the preparation method described above, the first reducing agent includes ferrous sulfate, cuprous sulfate, EDTA-iron sodium salt, or EDTA-copper sodium salt; the second reducing agent includes sodium formaldehyde sulfoxylate or glucose.

[0028] The chelating agent described in this invention is not particularly limited. As a specific embodiment of the preparation method described above, the chelating agent includes EDTA-tetrasodium salt or sodium aminotriacetate.

[0029] The oxygen scavenger described in this invention is not particularly limited. As a specific embodiment of the preparation method described above, the oxygen scavenger includes one of sodium dithionite, dimethyl ketoxime, isoascorbic acid, carbazide, or N-isopropylhydroxylamine.

[0030] In one specific embodiment of the preparation method described above in this invention, the pre-emulsification time is 40 to 60 minutes.

[0031] The organic hydrogen peroxide oxidant described in this invention is not particularly limited. As a specific embodiment of the preparation method described above, the organic hydrogen peroxide oxidant includes one of cumene hydrogen peroxide, dicumene hydrogen peroxide, or p-monane hydrogen peroxide.

[0032] In one specific embodiment of the preparation method described above in this invention, the polymerization temperature is 4.5–8°C.

[0033] The terminator described in this invention is not particularly limited. As a specific embodiment of the preparation method described above, the terminator includes one or a combination of hydroxylamine sulfate, diethylhydroxylamine, and hydroquinone.

[0034] In this invention, the conversion rates of the three monomers acrylonitrile, butadiene, and isoprene are measured using the conventional dry matter method used in the art.

[0035] On the other hand, the present invention also provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by the above-described method for preparing the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber.

[0036] As a specific embodiment of the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber described above in this invention, the content of acrylonitrile is 39-50% and the content of isoprene is 18-37% based on 100% of the total weight of the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber. The raw rubber of the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber has a Mooney viscosity of 40-70, a swelling degree of <26%, a tensile strength of >27 MPa, a 300% elongation of 15-19 MPa, a glass transition temperature of -11 to -6°C, and a Shore A hardness of 68-73. It is evident that the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber provided by this invention exhibits excellent physical properties and superior oil resistance and high-temperature resistance.

[0037] In another aspect, the present invention also provides a rubber diaphragm, which is made from the oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber described above.

[0038] In another aspect, the present invention also provides a diaphragm pump, which includes the rubber diaphragm described above.

[0039] This invention uses acrylonitrile, butadiene, and isoprene as monomers and employs a low-temperature emulsion polymerization method. Through the introduction of fluorinated monomer copolymerization, multi-stage addition of butadiene and / or isoprene, and the addition of a molecular weight regulator, a fluorinated acrylonitrile-butadiene-isoprene rubber with high bound nitrile content is prepared. The preparation method provided by this invention improves the uniform distribution of nitrile chain segments in the polymer chain of the high-bound-nitrile-content acrylonitrile-butadiene-isoprene rubber by multi-stage addition of butadiene and / or isoprene. Furthermore, the introduction of fluorinated monomers enhances the product's oil and solvent resistance, solving the problem of poor high-temperature oil resistance in general-purpose nitrile rubber under harsh conditions, thereby broadening the application range of nitrile rubber. The preparation method provided by this invention also improves the physical and mechanical properties and processing performance of the resulting product by introducing isoprene. In addition, the introduction of isoprene increases the number of methyl groups on the side chains of the product's molecular chain, thereby reducing the flexibility of the molecular chain, increasing the glass transition temperature, and enhancing the product's heat resistance.

[0040] In summary, the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber provided by this invention possesses excellent oil and solvent resistance, heat resistance, fatigue resistance, as well as superior mechanical and processing properties. It can be used in petrochemical and other fields where comprehensive performance requirements such as oil resistance and mechanical properties are high. For example, it can be used as a rubber diaphragm in a diaphragm pump, which can extend the service life of the rubber diaphragm, thereby reducing costs and improving equipment efficiency. Detailed Implementation

[0041] It should be noted that the term "comprising" and any variations thereof in the specification and claims of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0042] The "range" disclosed in this invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for specific parameters, it is also understandable that ranges of 60–110 and 80–120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5.

[0043] In this invention, unless otherwise specified, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this invention, and "0~5" is simply a shortened representation of these numerical combinations.

[0044] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in this invention can be combined with each other to form new technical solutions.

[0045] In this invention, unless otherwise specified, all technical features and preferred features mentioned in this invention can be combined with each other to form new technical solutions.

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the appendix and embodiments. The embodiments described below are some, but not all, embodiments of this invention, and are only used to illustrate the invention, and should not be considered as limiting the scope of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially. The polymerization reactor used in the embodiments is a 15L emulsion polymerization reactor with a stirrer. Unless otherwise specified, "parts" and "%" mentioned in the embodiments refer to parts by weight or percentage by mass.

[0047] Example 1

[0048] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0049] 260 parts of demineralized water, 3.3 parts of sodium dodecylbenzenesulfonate, 0.4 parts of dispersant N, 0.2 parts of sodium carbonate, 0.024 parts of sodium formaldehyde sulfoxylate, 0.009 parts of EDTA-sodium iron salt, 0.02 parts of EDTA-tetrasodium salt, 0.38 parts of tert-dodecyl mercaptan, 48.0 parts of acrylonitrile, 22.0 parts of isoprene, and 0.01 parts of oxygen scavenger sodium dithionite were added sequentially to the polymerization reactor. After evacuation, the reactor was purged with nitrogen three times. Then, 22.0 parts of monomer butadiene were added and pre-emulsified for 40-60 minutes. When the temperature of the polymerization reactor dropped to 5°C, 0.051 parts of dicumyl peroxide were added to start the polymerization reaction.

[0050] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 28%, 2.0 parts of butadiene are added; when the monomer conversion rate reaches 42%, 2.0 parts of isoprene, 2.0 parts of hexafluorobutyl methacrylate, 0.1 parts of tert-dodecyl mercaptan, and 3.0 parts of sodium dodecylbenzenesulfonate are added respectively; when the monomer conversion rate reaches 58%, 2.0 parts of butadiene and 2.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 80%, 0.05 parts of diethylhydroxylamine and 0.07 parts of hydroquinone are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, namely, oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0051] Example 2

[0052] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0053] Add 240 parts of deionized water, 3.8 parts of sodium dodecylbenzenesulfonate, 0.5 parts of potassium oleate, 0.2 parts of sodium carbonate, 0.056 parts of sodium formaldehyde sulfoxylate, 0.01 parts of EDTA-sodium iron salt, 0.025 parts of EDTA-tetrasodium salt, 0.36 parts of tert-dodecyl mercaptan, 45.0 parts of acrylonitrile, 25.0 parts of isoprene, and 0.01 parts of sodium dithionite (oxygen scavenger) to the polymerization reactor in sequence. After evacuation, purge with nitrogen three times. Then add 20.0 parts of butadiene monomer and pre-emulsify for 40-60 minutes. When the temperature of the polymerization reactor drops to 5°C, add 0.062 parts of dicumyl peroxide to start the polymerization reaction.

[0054] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 25%, 3.0 parts of butadiene are added; when the monomer conversion rate reaches 42%, 3.0 parts of isoprene, 1.0 part of trifluoroethyl methacrylate, 0.12 parts of tert-dodecyl mercaptan, and 2.0 parts of sodium dodecylbenzenesulfonate are added respectively; when the monomer conversion rate reaches 58%, 2.0 parts of butadiene and 2.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 79%, 0.05 parts of diethylhydroxylamine and 0.1 parts of hydroxylamine sulfate are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, namely, oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0055] Example 3

[0056] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0057] 230 parts of deionized water, 3.3 parts of sodium dodecylbenzenesulfonate, 0.8 parts of potassium synthetic fatty acid, 0.3 parts of sodium acetate, 0.033 parts of sodium formaldehyde sulfoxylate, 0.009 parts of EDTA-sodium iron salt, 0.02 parts of EDTA-tetrasodium salt, 0.39 parts of tert-dodecyl mercaptan, 43.5 parts of acrylonitrile, 25.0 parts of isoprene, and 0.01 parts of sodium dithionite (oxygen scavenger) were added sequentially to the polymerization reactor. After evacuation, the reactor was purged with nitrogen three times. Then, 15.0 parts of butadiene monomer were added and pre-emulsified for 40-60 minutes. When the temperature of the polymerization reactor dropped to 5°C, 0.062 parts of dicumyl peroxide were added to start the polymerization reaction.

[0058] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 26%, 3.0 parts of butadiene are added; when the monomer conversion rate reaches 40%, 6.5 parts of isoprene, 3.0 parts of dodecylfluoroheptyl methacrylate, and 5.0 parts of sodium dodecylbenzenesulfonate are added; when the monomer conversion rate reaches 45%, 0.13 parts of tert-dodecyl mercaptan are added; when the monomer conversion rate reaches 58%, 2.0 parts of butadiene and 5.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 80%, 0.05 parts of diethylhydroxylamine and 0.1 parts of hydroxylamine sulfate are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, i.e., oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0059] Example 4

[0060] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0061] Add 290 parts of demineralized water, 4.5 parts of sodium dodecylbenzenesulfonate, 0.8 parts of dispersant N, 0.2 parts of sodium acetate, 0.03 parts of sodium formaldehyde sulfoxylate, 0.007 parts of ferrous sulfate, 0.05 parts of EDTA-tetrasodium salt, 0.40 parts of tert-dodecyl mercaptan, 47.0 parts of acrylonitrile, 16.0 parts of isoprene, and 0.01 parts of oxygen scavenger sodium dithionite to the polymerization reactor in sequence. After evacuation, purge with nitrogen three times, then add 23.0 parts of monomer butadiene and pre-emulsify for 40-60 minutes. When the temperature of the polymerization reactor drops to 5°C, add 0.055 parts of dicumyl peroxide to start the polymerization reaction.

[0062] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 27%, 7.0 parts of butadiene are added; when the monomer conversion rate reaches 44%, 2.0 parts of isoprene, 3.0 parts of trifluoroethyl methacrylate, 0.1 parts of n-dodecyl mercaptan, and 2.0 parts of sodium dodecylbenzenesulfonate are added respectively; when the monomer conversion rate reaches 60%, 3.0 parts of butadiene and 2.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 81%, 0.05 parts of diethylhydroxylamine and 0.08 parts of hydroquinone are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, namely, oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0063] Example 5

[0064] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0065] 270 parts of demineralized water, 4.0 parts of sodium dodecylbenzenesulfonate, 0.6 parts of dispersant N, 0.4 parts of sodium carbonate, 0.028 parts of sodium formaldehyde sulfoxylate, 0.007 parts of EDTA-sodium iron salt, 0.03 parts of EDTA-tetrasodium salt, 0.36 parts of tert-dodecyl mercaptan, 46.0 parts of acrylonitrile, 21.0 parts of isoprene, and 0.01 parts of oxygen scavenger sodium dithionite were added sequentially to the polymerization reactor. After evacuation, the reactor was purged with nitrogen three times. Then, 21.0 parts of monomer butadiene were added and pre-emulsified for 40-60 minutes. When the temperature of the polymerization reactor dropped to 5°C, 0.046 parts of dicumyl peroxide were added to start the polymerization reaction.

[0066] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 25%, 3.0 parts of butadiene are added; when the monomer conversion rate reaches 41%, 3.0 parts of isoprene, 3.0 parts of trifluoroethyl methacrylate, 0.10 parts of n-dodecyl mercaptan, and 2.0 parts of sodium dodecylbenzenesulfonate are added respectively; when the monomer conversion rate reaches 58%, 3.0 parts of butadiene and 3.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 78%, 0.05 parts of diethylhydroxylamine and 0.08 parts of hydroxylamine sulfate are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, namely, oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0067] Example 6

[0068] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0069] 230 parts of demineralized water, 3.8 parts of sodium dodecylbenzenesulfonate, 0.7 parts of dispersant N, 0.09 parts of sodium carbonate, 0.033 parts of sodium formaldehyde sulfoxylate, 0.009 parts of EDTA-sodium iron salt, 0.05 parts of EDTA-tetrasodium salt, 0.35 parts of tert-dodecyl mercaptan, 44.0 parts of acrylonitrile, 20.0 parts of isoprene, and 0.01 parts of oxygen scavenger sodium dithionite were added sequentially to the polymerization reactor. After evacuation, the reactor was purged with nitrogen three times. Then, 20.0 parts of monomer butadiene were added and pre-emulsified for 40-60 minutes. When the temperature of the polymerization reactor dropped to 5°C, 0.046 parts of dicumyl peroxide were added to start the polymerization reaction.

[0070] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 28%, 4.0 parts of butadiene are added; when the monomer conversion rate reaches 43%, 4.0 parts of isoprene, 1.5 parts of dodecylfluoroheptyl methacrylate, 0.10 parts of tert-dodecyl mercaptan, and 1.0 part of sodium dodecylbenzenesulfonate are added respectively; when the monomer conversion rate reaches 58%, 4.0 parts of butadiene and 4.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 78%, 0.05 parts of diethylhydroxylamine and 0.08 parts of hydroxylamine sulfate are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, namely, oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0071] Example 7

[0072] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0073] 220 parts of demineralized water, 3.6 parts of sodium dodecylbenzenesulfonate, 0.5 parts of dispersant N, 0.06 parts of sodium carbonate, 0.031 parts of sodium formaldehyde sulfoxylate, 0.01 parts of EDTA-sodium iron salt, 0.03 parts of EDTA-tetrasodium salt, 0.40 parts of tert-dodecyl mercaptan, 46.0 parts of acrylonitrile, 18.0 parts of isoprene, and 0.01 parts of oxygen scavenger sodium dithionite were added sequentially to the polymerization reactor. After evacuation, the reactor was purged with nitrogen three times. Then, 18.0 parts of monomer butadiene were added and pre-emulsified for 40-60 minutes. When the temperature of the polymerization reactor dropped to 5°C, 0.05 parts of dicumyl peroxide were added to start the polymerization reaction.

[0074] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 28%, 6.0 parts of butadiene are added; when the monomer conversion rate reaches 44%, 6.0 parts of isoprene, 1.8 parts of dodecylfluoroheptyl methacrylate, 0.13 parts of tert-dodecyl mercaptan, and 2.0 parts of sodium dodecylbenzenesulfonate are added respectively; when the monomer conversion rate reaches 58%, 3.0 parts of butadiene and 3.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 80%, 0.05 parts of diethylhydroxylamine and 0.08 parts of hydroxylamine sulfate are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, namely, oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0075] Example 8

[0076] This embodiment provides an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by a method including the following specific steps:

[0077] Add 240 parts of deionized water, 3.9 parts of sodium dodecylbenzenesulfonate, 0.7 parts of dispersant N, 0.1 parts of sodium carbonate, 0.042 parts of sodium formaldehyde sulfoxylate, 0.007 parts of EDTA-sodium iron salt, 0.03 parts of EDTA-tetrasodium salt, 0.38 parts of tert-dodecyl mercaptan, 45.0 parts of acrylonitrile, 15.0 parts of isoprene, and 0.01 parts of oxygen scavenger sodium dithionite to the reactor in sequence. After evacuation, purge with nitrogen three times, then add 26.0 parts of monomer butadiene and pre-emulsify for 40-60 minutes. When the temperature of the polymerization reactor drops to 5°C, add 0.041 parts of dicumyl peroxide to start the polymerization reaction.

[0078] When the conversion rate of the three monomers acrylonitrile, butadiene, and isoprene reaches 27%, 6.0 parts of butadiene are added; when the monomer conversion rate reaches 43.5%, 3.0 parts of isoprene, 1.2 parts of dodecylfluoroheptyl methacrylate, 0.10 parts of tert-dodecyl mercaptan, and 2.0 parts of sodium dodecylbenzenesulfonate are added respectively; when the monomer conversion rate reaches 58%, 3.0 parts of butadiene and 2.0 parts of isoprene are added respectively; when the monomer conversion rate reaches 81%, 0.05 parts of diethylhydroxylamine and 0.08 parts of hydroxylamine sulfate are added to terminate the polymerization reaction, resulting in fluorinated acrylonitrile-butadiene-isoprene rubber, namely, oil-resistant and high-strength modified acrylonitrile-butadiene-isoprene rubber, the properties of which are shown in Table 1.

[0079] Comparative Example 1

[0080] This comparative example provides a fluorinated acrylonitrile-butadiene-isoprene rubber, which differs from Example 1 only in that:

[0081] The initial feed consisted of 36.0 parts of acrylonitrile, 28.0 parts of butadiene, and 28.0 parts of isoprene. The properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0082] Comparative Example 2

[0083] This comparative example provides a fluorinated acrylonitrile-butadiene rubber, which differs from Example 2 only in that:

[0084] Copolymerization was carried out without the addition of a third monomer, isoprene. The initial feed consisted of 45.0 parts of acrylonitrile and 45.0 parts of butadiene. When the monomer conversion rate reached 42%, 3.0 parts of butadiene, 1.0 part of trifluoroethyl methacrylate, 0.12 parts of tert-dodecyl mercaptan, and 2.0 parts of emulsifier were added. When the monomer conversion rate reached 58%, 4.0 parts of butadiene were added. The properties of the fluorinated acrylonitrile-butadiene rubber obtained in this comparative example are shown in Table 1.

[0085] Comparative Example 3

[0086] This comparative example provides a fluorinated acrylonitrile-isoprene rubber, which differs from Example 3 only in that:

[0087] The initial feed consisted of only two monomers: acrylonitrile and isoprene. The initial feed amounts of acrylonitrile and isoprene were 43.5 parts and 40.0 parts, respectively. When the monomer conversion reached 26%, 3.0 parts of isoprene were added. When the monomer conversion reached 58%, 7.0 parts of isoprene were added. The properties of the fluorinated acrylonitrile-isoprene rubber obtained in this comparative example are shown in Table 1.

[0088] Comparative Example 4

[0089] This comparative example provides a fluorinated acrylonitrile-butadiene-isoprene rubber, which differs from Example 4 only in that:

[0090] The monomer was added only once, that is, when the monomer conversion reached 37%, 10.0 parts of butadiene and 5.0 parts of isoprene were added respectively. The properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0091] Comparative Example 5

[0092] This comparative example provides a fluorinated acrylonitrile-butadiene-isoprene rubber, which differs from Example 5 only in that:

[0093] The monomer was added only once, that is, when the monomer conversion rate reached 58%, 6.0 parts of butadiene and 6.0 parts of isoprene were added respectively. The properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0094] Comparative Example 6

[0095] This comparative example provides a fluorinated acrylonitrile-butadiene-isoprene rubber, which differs from Example 6 only in that:

[0096] No monomers were added during the reaction. The initial feed consisted of 44.0 parts of acrylonitrile, 28.0 parts of butadiene, and 28.0 parts of isoprene. The properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0097] Comparative Example 7

[0098] This comparative example provides a fluorinated acrylonitrile-butadiene-isoprene rubber, which differs from Example 7 only in that:

[0099] The initial feeding of butadiene is not within the scope of protection claimed in this invention. Specifically, in the initial feeding, the amounts of butadiene and isoprene are 9.0 parts and 27.0 parts, respectively. The properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0100] Comparative Example 8

[0101] This comparative example provides a fluorinated acrylonitrile-butadiene-isoprene rubber, which differs from Example 8 only in that:

[0102] The initial feeding of isoprene is not within the scope of protection claimed in this invention. Specifically, in the initial feeding, the amounts of butadiene and isoprene are 33.0 parts and 8.0 parts, respectively. The properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0103] Comparative Example 9

[0104] This comparative example provides an acrylonitrile-butadiene-isoprene rubber, which differs from Example 1 only in that:

[0105] Without introducing fluorinated monomers for copolymerization, when the monomer conversion rate reached 42%, 2.0 parts of isoprene, 0.1 parts of tert-dodecyl mercaptan, and 3.0 parts of emulsifier were added respectively. The properties of the acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0106] Comparative Example 10

[0107] This comparative example provides a fluorinated acrylonitrile-butadiene-isoprene rubber, which differs from Example 4 only in that:

[0108] The timing of the first addition of butadiene and the timing of subsequent additions of butadiene and isoprene are not within the scope of protection claimed in this invention. Specifically: when the monomer conversion rate reaches 10%, 7.0 parts of butadiene are added; when the monomer conversion rate reaches 70%, 3.0 parts of butadiene and 2.0 parts of isoprene are added respectively. The properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained in this comparative example are shown in Table 1.

[0109] Table 1. Performance test results of the products obtained in the examples and comparative examples.

[0110]

[0111]

[0112] Note:

[0113] The acrylonitrile content was determined according to SH / T1157.2-2015;

[0114] The glass transition temperature was measured according to SH / T 1771-2010;

[0115] Mechanical properties (tensile strength and 300% elongation) were measured according to GB / T 528-2009;

[0116] The degree of swelling was measured according to SH / T 1159-2010;

[0117] The Shore A hardness was measured according to GB / T 531.1-2008;

[0118] The Mooney viscosity was measured according to the roll-passing method in GB / T 1232.1;

[0119] The isoprene content was determined by 1H NMR spectroscopy.

[0120] Comparing the experimental data of Example 1 and Comparative Example 1 shown in Table 1 above, it can be seen that, compared with Example 1, the amount of acrylonitrile monomer used in Comparative Example 1 is less, which reduces the content of bound acrylonitrile in the fluorinated acrylonitrile-butadiene-isoprene rubber, resulting in varying degrees of reduction in the oil resistance and mechanical properties of the rubber product obtained in Comparative Example 1.

[0121] Comparing the experimental data of Example 2 and Comparative Example 2 shown in Table 1 above, it can be seen that, compared with Example 2, the mechanical properties and heat resistance of the fluorinated acrylonitrile-butadiene rubber prepared in Comparative Example 2 are reduced because the third monomer isoprene is not used. At the same time, its oil resistance is slightly reduced compared with the oil resistance of the fluorinated acrylonitrile-butadiene-isoprene rubber prepared in Example 2.

[0122] Comparing the experimental data of Example 3 and Comparative Example 3 shown in Table 1 above, it can be seen that, compared with Example 3, the mechanical properties of the fluorinated acrylonitrile-isoprene rubber prepared in Comparative Example 3 are reduced due to the absence of butadiene. At the same time, its oil resistance is slightly reduced compared with the oil resistance of the fluorinated acrylonitrile-butadiene-isoprene rubber prepared in Example 3.

[0123] Comparing the experimental data of Example 4 and Comparative Example 4 shown in Table 1 above, it can be seen that the initial ratio of acrylonitrile to butadiene is relatively large. That is, when the ratio of acrylonitrile to butadiene is higher than the constant ratio point, especially when the bound acrylonitrile content is higher than 40%, butadiene will polymerize first. Moreover, compared with Example 4, Comparative Example 4 only added monomer once during the polymerization reaction, resulting in an uneven distribution of nitrile units in the polymer chain. This leads to a lower bound acrylonitrile content in the resulting product, and reduced oil resistance and mechanical properties. This also proves that in Example 4 of the present invention, the addition of butadiene and / or isoprene in multiple stages improves the uniform distribution of nitrile units in the polymer chain of acrylonitrile-butadiene-isoprene rubber with high bound nitrile content, thereby improving the oil resistance and mechanical properties of the rubber product.

[0124] Comparing the experimental data of Example 5 and Comparative Example 5 shown in Table 1 above, it can be seen that, compared to Example 5, Comparative Example 5 only added monomer once during the polymerization reaction, resulting in an uneven distribution of nitrile units in the polymer chain. This led to a lower bound acrylonitrile content in the resulting product, and reduced oil resistance and mechanical properties. This also demonstrates that Example 5 of the present invention, by adding butadiene and / or isoprene in multiple stages, improved the uniform distribution of nitrile units in the polymer chain of acrylonitrile-butadiene-isoprene rubber with high bound nitrile content, thereby improving the oil resistance and mechanical properties of the rubber product.

[0125] Comparing the experimental data of Example 6 and Comparative Example 6 shown in Table 1 above, it can be seen that, compared to Example 6, Comparative Example 6 did not add monomers during the polymerization reaction. The results show that the bound acrylonitrile content of the product is significantly lower than the monomer feed ratio, resulting in an uneven distribution of nitrile units in the polymer chain. This leads to a lower bound acrylonitrile content in the resulting product, and reduced oil resistance and mechanical properties. This also proves that Example 6 of the present invention, through multi-stage addition of butadiene and / or isoprene, improves the uniform distribution of nitrile units in the polymer chain of acrylonitrile-butadiene-isoprene rubber with high bound acrylonitrile content, thereby increasing the bound acrylonitrile content of the rubber product (and narrowing the gap between it and the monomer feed ratio) and the oil resistance and mechanical properties of the rubber product.

[0126] Comparing the experimental data of Example 7 and Comparative Example 7, as well as Example 8 and Comparative Example 8 shown in Table 1 above, it can be seen that, compared with Example 7 and Example 8, the initial feed of butadiene in Comparative Example 7 and isoprene in Comparative Example 8 is lower, and both are outside the range of feed amounts claimed in this invention, thus causing a decrease in the mechanical properties of the fluorinated acrylonitrile-butadiene-isoprene rubber obtained therefrom.

[0127] Comparing the experimental data of Example 1 and Comparative Example 9 shown in Table 1 above, it can be seen that, compared with Example 1, Comparative Example 9 did not use fluorinated monomers. Although the acrylonitrile content of the rubber products obtained by the two were roughly the same, the swelling degree of the rubber product obtained in Comparative Example 9 was significantly higher than that of the rubber product obtained in Example 1. This indicates that the addition of fluorinated monomers significantly improved the oil resistance of the rubber product.

[0128] Comparing the experimental data of Example 4 and Comparative Example 10 shown in Table 1 above, it can be seen that, compared with Example 4, the oil resistance and mechanical properties of the fluorinated acrylonitrile-butadiene-isoprene rubber prepared in Comparative Example 10 are reduced because the timing of the first addition of butadiene and the timing of the subsequent addition of butadiene and isoprene are not within the scope of protection claimed in this invention.

[0129] This invention uses acrylonitrile, butadiene, and isoprene as monomers, employs a low-temperature emulsion polymerization method, and introduces fluorinated monomer copolymerization, multi-stage addition of butadiene and / or isoprene, and the addition of molecular weight regulators to prepare acrylonitrile-butadiene-isoprene rubber with high bound nitrile content. The preparation method provided by this invention improves the uniform distribution of nitrile segments in the polymer chain of the high bound nitrile content acrylonitrile-butadiene-isoprene rubber by multi-stage addition of butadiene and / or isoprene. Furthermore, the introduction of fluorinated monomers improves the product's oil and solvent resistance, solving the problem of poor high-temperature oil resistance in general-purpose nitrile rubber under harsh conditions, thus broadening the application fields of nitrile rubber. The preparation method provided by this invention also improves the physical and mechanical properties and processing performance of the obtained product by introducing isoprene. In addition, the introduction of isoprene increases the number of methyl groups on the side chains of the product's molecular chain, thereby reducing the flexibility of the molecular chain, increasing the glass transition temperature, and enhancing the product's heat resistance.

[0130] In summary, the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber provided in this invention possesses excellent oil and solvent resistance, heat resistance, fatigue resistance, as well as superior mechanical and processing properties. It can be used in petrochemical and other fields where comprehensive performance requirements such as oil resistance and mechanical properties are high. For example, it can be used as a rubber diaphragm in a diaphragm pump, which can extend the service life of the rubber diaphragm, thereby reducing costs and improving equipment efficiency.

[0131] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this invention can be freely combined and used.

Claims

1. A method for preparing an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, characterized in that, The preparation method includes: Based on a total weight of 100 parts for acrylonitrile, butadiene, and isoprene, add 220-295 parts of deionized water, 1.5-10.0 parts of emulsifier, 0.001-0.5 parts of pH buffer, 0.0005-0.2 parts of first reducing agent, 0.0004-0.2 parts of second reducing agent, 0.0003-0.4 parts of chelating agent, 0.1-1.5 parts of molecular weight regulator, 39-51 parts of acrylonitrile, 15-41 parts of isoprene, and 0.01-0.1 parts of oxygen scavenger to the polymerization reactor. After nitrogen purging, 15-41 parts of butadiene are added and pre-emulsified, followed by 0.005-0.5 parts of organic hydrogen peroxide oxidant, so that the three monomers acrylonitrile, butadiene and isoprene can undergo copolymerization reaction at a polymerization temperature of 3-15℃. When the conversion rates of acrylonitrile, butadiene, and isoprene reach 25-30%, 1-8 parts of butadiene are added. When the monomer conversion rate reaches 40-45%, 1-8 parts of isoprene, 0.1-5.0 parts of fluorinated monomer, and emulsifier are added. When the monomer conversion rate reaches 55-65%, 1-8 parts of butadiene and 1-8 parts of isoprene are added again. When the monomer conversion rate reaches 35-65%, 0.01-0.5 parts of molecular weight regulator are added. When the monomer conversion rate reaches 78-83%, 0.1-1 parts of terminator are added to terminate the copolymerization reaction, resulting in an oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber.

2. The preparation method according to claim 1, characterized in that, The molecular weight regulator is added simultaneously with isoprene, or simultaneously with butadiene and isoprene.

3. The preparation method according to claim 2, characterized in that, Add a molecular weight regulator when the monomer conversion rate reaches 40-45%.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The molecular weight regulator includes one or a combination of several of tert-dodecyl mercaptan, n-dodecyl mercaptan, and dithiodiisopropyl xanthate.

5. The preparation method according to claim 1, characterized in that, The fluorinated monomer is a fluorinated fatty acid ester monomer that can copolymerize with butadiene, acrylonitrile, and isoprene, including one of trifluoroethyl methacrylate, hexafluorobutyl methacrylate, or dodecafluoroheptyl methacrylate.

6. The preparation method according to claim 1, characterized in that, The amount of the fluorinated monomer used is 1.0 to 3.0 parts.

7. The preparation method according to claim 1, characterized in that, When the monomer conversion rate reaches 40-45%, the amount of emulsifier to be added is 1.0-6.0 parts.

8. The preparation method according to claim 1 or 7, characterized in that, The emulsifier includes one or a combination of several of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, dispersant N, potassium synthetic fatty acid, potassium oleate, and potassium disproportionated rosinate.

9. The preparation method according to claim 1, characterized in that, The pH buffer includes sodium carbonate or sodium acetate.

10. The preparation method according to claim 1, characterized in that, The first reducing agent includes ferrous sulfate, cuprous sulfate, EDTA-iron sodium salt, or EDTA-copper sodium salt; the second reducing agent includes sodium formaldehyde sulfoxylate or glucose.

11. The preparation method according to claim 1, characterized in that, The chelating agent includes EDTA-tetrasodium salt or sodium aminotriacetate.

12. The preparation method according to claim 1, characterized in that, The oxygen scavenger includes one of sodium dithionite, dimethyl ketoxime, isoascorbic acid, carbazide, or N-isopropylhydroxylamine.

13. The preparation method according to claim 1, characterized in that, The pre-emulsification time is 40-60 minutes.

14. The preparation method according to claim 1, characterized in that, The organic hydrogen peroxide oxidant includes one of cumene hydrogen peroxide, dicumene hydrogen peroxide, or p-menthane hydrogen peroxide.

15. The preparation method according to claim 1, characterized in that, The polymerization temperature is 4.5~8℃.

16. The preparation method according to claim 1, characterized in that, The terminating agent includes one or a combination of several of hydroxylamine sulfate, diethylhydroxylamine, and hydroquinone.

17. An oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, which is prepared by the method of preparing the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber according to any one of claims 1 to 16.

18. The oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber according to claim 17, characterized in that, Based on 100% of the total weight of the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber, the acrylonitrile content is 39-50%, and the isoprene content is 18-37%; the raw rubber of the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber has a Mooney viscosity of 40-70, a swelling degree of <26%, a tensile strength of >27 MPa, a 300% elongation of 15-19 MPa, and a glass transition temperature of -11 to -6. o C, Shore A hardness is 68~73.

19. A rubber diaphragm made from the oil-resistant, high-strength modified acrylonitrile-butadiene-isoprene rubber as described in claim 17 or 18.

20. A diaphragm pump comprising the rubber diaphragm of claim 19.

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