Hydrogenated nitrile rubber sealing material with wide temperature range and anti-gas explosion and preparation method thereof

Abstract

This invention discloses a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile butadiene rubber sealing material and its preparation method, relating to the field of rubber technology. The hydrogenated nitrile butadiene rubber sealing material comprises the following raw materials, by weight: 100 parts hydrogenated nitrile butadiene rubber, 6-10 parts methyl methacrylate, 12-18 parts nanocomposite filler, 4-6 parts gradient crosslinking agent, and 3-5 parts functional additives. The nanocomposite material comprises graphene and boron nitride in a mass ratio of 2:1; the gradient crosslinking agent is composed of peroxide and sulfur; the functional additives include one or more of cold-resistant plasticizers, antioxidants, and anti-aging agents. The hydrogenated nitrile butadiene rubber sealing material of this application exhibits excellent high-temperature stability and low-temperature elasticity, while also possessing good gas-explosion resistance, facilitating practical applications.

Description

Technical Field

[0001] This invention relates to the field of rubber technology, specifically to a wide-temperature-range anti-gas-explosion hydrogenated nitrile butadiene rubber sealing material and its preparation method. Background Technology

[0002] Hydrogenated nitrile butadiene rubber (NBR) is a high-performance synthetic rubber produced by hydrogenation of NBR. It retains the advantages of NBR, such as good oil resistance, while significantly improving heat resistance, ozone resistance, chemical corrosion resistance, and mechanical properties. It is widely used in various fields, such as automotive engine parts, transmission system parts, and seals for oil extraction equipment.

[0003] However, in existing technologies, hydrogenated nitrile butadiene rubber has a narrow temperature range, typically between -30°C and 120°C. Its performance deteriorates significantly under extreme temperatures. For example, during long-term use at high temperatures, it faces problems such as the breakage of cross-links in the rubber, leading to a decrease in tensile strength, and during use at low temperatures, the movement of molecular chain segments is hindered, resulting in hardening and a decrease in elongation. It also suffers from poor low-temperature elasticity. Another option has a low critical pressure for gas explosion when used under high pressure, generally less than 8 MPa, which is difficult to meet the usage standards.

[0004] In summary, solving the above problems and preparing a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile rubber sealing material is of great significance. Summary of the Invention

[0005] The purpose of this invention is to provide a wide-temperature-range anti-gas-explosion hydrogenated nitrile rubber sealing material and its preparation method, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A wide-temperature-range gas explosion-resistant hydrogenated nitrile butadiene rubber sealing material, comprising the following raw materials in parts by weight: 100 parts hydrogenated nitrile butadiene rubber, 6-10 parts methyl methacrylate, 12-18 parts nanocomposite filler, 4-6 parts gradient crosslinking agent, and 3-5 parts functional additives.

[0008] In a more optimized manner, the nanocomposite material comprises graphene and boron nitride in a mass ratio of 2:1; the gradient crosslinking agent is composed of peroxide and sulfur; and the functional additives include one or more of cold-resistant plasticizers, antioxidants, and anti-aging agents.

[0009] More preferably, the hydrogenated nitrile butadiene rubber comprises a base hydrogenated nitrile butadiene rubber and a modified nitrile butadiene rubber in a mass ratio of 7~8:2~3.

[0010] A more optimized method for preparing the modified nitrile rubber is as follows:

[0011] (1) Add nitrile rubber to chlorobenzene and stir evenly. Gradually add a mixed solution of formic acid and hydrogen peroxide. Stir and react at 40~45℃ for 6~8h. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0012] (2) Add amino-polyethylene glycol-carboxylic acid to deionized water and stir evenly. Add activator and aminoacetonitrile, stir at 40~50℃ for 3~4h, distill under reduced pressure, wash, and dry to obtain amino-polyethylene glycol-acetonitrile;

[0013] (3) Add epoxidized nitrile rubber to chlorobenzene and stir evenly. Add palladium catalyst and stir at 100-120℃ for 2-3 hours under hydrogen pressure of 3-5 MPa. After exhausting the gas, obtain the adhesive solution. Add amino-polyethylene glycol-acetonitrile and potassium hydroxide to the adhesive solution and stir at 60-70℃ for 10-12 hours under nitrogen atmosphere. Use anhydrous ethanol to precipitate the adhesive, wash and dry to obtain modified nitrile rubber.

[0014] More preferably, the epoxidized nitrile rubber comprises the following raw materials, by weight: 8-10 parts nitrile rubber, 100 parts chlorobenzene, 1.4-1.6 parts a mixed solution of formic acid and hydrogen peroxide; the mass ratio of formic acid to hydrogen peroxide is 0.65:0.75-0.95;

[0015] The amino-polyethylene glycol-acetonitrile comprises the following raw materials, by weight: 20-22 parts amino-polyethylene glycol-carboxylic acid, 4-6 parts activator, and 1.1-1.2 parts aminoacetonitrile;

[0016] The modified nitrile rubber comprises the following raw materials, by weight: 8-10 parts epoxidized nitrile rubber, 100 parts chlorobenzene, 0.5-1 parts palladium catalyst, 25-30 parts amino-polyethylene glycol-acetonitrile, and 3-4 parts potassium hydroxide.

[0017] Ideally, the molecular weight of the amino-polyethylene glycol-carboxylic acid is 1000-1500.

[0018] In a more optimized manner, the hydrogenated nitrile rubber sealing material further includes the following raw materials, by weight: 1.5 to 1.8 parts triallyl isocyanate, 1 to 1.2 parts stearic acid, and 4 to 5 parts zinc oxide.

[0019] A method for preparing a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile butadiene rubber sealing material includes the following steps:

[0020] S1: Weigh out graphene and boron nitride according to the mass ratio to use as nanocomposite fillers;

[0021] S2: Hydrogenated nitrile butadiene rubber and methyl methacrylate are mixed once; nanocomposite filler is added and ultrasonically dispersed; gradient crosslinking agent and functional additives are added and mixed a second time; plate vulcanization is performed; post-treatment is carried out; room temperature recovery and vacuum drying are performed to obtain hydrogenated nitrile butadiene rubber sealing material.

[0022] More optimized, the process parameters for the first internal mixing are: mixing at 105~115℃ and a rotation speed of 30~50 rpm for 8~10 minutes; the process parameters for the ultrasonic dispersion are: dispersion at a power of 500~700W for 10~30 minutes; the process parameters for the second internal mixing are: mixing at 105~115℃ and a rotation speed of 50~60 rpm for 10~12 minutes; and the process parameters for the flat vulcanization are: vulcanization at 170~180℃ and a pressure of 6~8 MPa for 15~25 minutes.

[0023] The post-treatment is liquid nitrogen cryogenic embrittlement, with process parameters of -200~-190℃ for 2~3 hours.

[0024] In a more optimized manner, the pretreatment of the graphene and boron nitride specifically includes the following steps:

[0025] S1: Weigh out graphene and boron nitride according to the mass ratio to use as nanocomposite fillers;

[0026] S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.4~0.6 are added to deionized water, wet-milled for 1~2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene is dispersed in tetrahydrofuran, 1-thioglycerol is added, the amount of 1-thioglycerol added is 20~30wt% of the boric acid intercalated graphene, stirred at 25℃ for 24 hours, filtered, washed and dried to obtain modified graphite. (2) Add boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.4~0.6 to deionized water, wet grind for 1~2 hours, filter and dry to obtain boron nitride with boric acid; disperse boron nitride with boric acid in tetrahydrofuran, add glycerol allyl ether, the amount of glycerol allyl ether added is 20~30wt% of boron nitride with boric acid, stir at 25°C for 24 hours, filter, wash and dry to obtain modified boron nitride;

[0027] S3: Hydrogenated nitrile butadiene rubber and methyl methacrylate are mixed once; modified graphene and modified boron nitride are added and ultrasonically dispersed; gradient crosslinking agent and functional additives are added and mixed a second time; plate vulcanization is performed; post-treatment is carried out; room temperature recovery and vacuum drying are performed to obtain hydrogenated nitrile butadiene rubber sealing material.

[0028] Compared with the prior art, the beneficial effects of this application are as follows: In this scheme, hydrogenated nitrile butadiene rubber is used as the main body, and methyl methacrylate is introduced as a copolymer modifier to maintain both strength and high and low temperature elongation; a specific ratio of graphene and boron nitride is introduced as nanocomposite fillers to construct a thermal management network and increase the temperature range; at the same time, a specific gradient crosslinking agent is added to regulate the crosslinking density of the rubber material, and embrittlement treatment is carried out in the post-processing to eliminate internal stress concentration, thereby improving the high temperature stability and low temperature elasticity of the hydrogenated nitrile butadiene rubber sealing material, thus promoting the improvement of temperature range and anti-gas explosion performance.

[0029] In a further proposed approach, modified nitrile butadiene rubber (NBR) is compounded with basic hydrogenated NBR to form the main hydrogenated NBR. By introducing modified NBR and utilizing its grafted toughening side chains of specific molecular weights, the overall performance is further improved.

[0030] Modified nitrile butadiene rubber (NBR) is prepared by epoxidizing NBR through a mixture of formic acid and hydrogen peroxide to partially epoxidize the carbon-carbon double bonds, followed by hydrogenation to obtain epoxidized NBR. Then, aminoacetonitrile is grafted onto amino-polyethylene glycol-carboxylic acid and reacted with the epoxy groups in the epoxidized NBR to introduce polyethylene glycol side chains. Compared to simple hydrogenated NBR, this application improves the toughness and low-temperature performance of the rubber by introducing epoxy groups and grafting polyethylene glycol as side chains. Introducing nitrile groups at the other end of the polyethylene glycol improves the compatibility of the side chains in the rubber, further enhancing performance. Simultaneously, the grafted amide bonds promote subsequent vulcanization, increasing the material's high-temperature stability and low-temperature elasticity. However, the molecular weight of the polyethylene glycol needs to be limited. If the molecular weight is too small, the toughening effect is limited; if the molecular weight is too large, it is difficult to disperse evenly in the matrix, leading to performance degradation.

[0031] In nitrile rubber, the introduction of graphene and boron nitride in a mass ratio of 2:1 helps to improve the thermal stability of the material and construct a thermal management network. The synergistic effect of the two can reduce the interfacial thermal resistance between the filler and the nitrile rubber matrix, enabling more efficient heat transfer. As a reinforcing material, they can also improve the overall mechanical strength. However, their direct use has poor compatibility with rubber materials. Therefore, the two are modified separately to improve their dispersibility in the system and effectively maximize their reinforcing properties.

[0032] The modified graphene is introduced by grafting thiol groups onto boric acid and 1-thioglycerol; the modified boron nitride is also introduced by grafting alkenyl groups onto glycerol allyl ether after boric acid intercalation. Boric acid intercalation avoids agglomeration of the nanofiller and improves its dispersibility in the rubber matrix; it also helps the nanofiller form a thermal management network, improving high-temperature stability. The thiol and alkenyl groups introduced into the modified graphene and modified boron nitride, respectively, can undergo click reactions upon heating, further forming a thermal management network and further improving the high-temperature stability, low-temperature elasticity, and wide temperature range of the hydrogenated nitrile rubber sealing material. The two materials have a synergistic effect. Detailed Implementation

[0033] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include: graphene with a sheet diameter of 0.5~5μm; boron nitride with a particle size of 100nm; basic hydrogenated nitrile rubber with an acrylonitrile content of 35~40%; nitrile rubber with an acrylonitrile content of 25~30%; amino-polyethylene glycol-carboxylic acid with a molecular weight of 1000; methyl methacrylate CAS number: 80-62-6; triallyl isocyanate CAS number: 1025-15-6; stearic acid CAS number: 57-11-4; 1,4-phenylenediboric acid CAS number: 4612-26-4; 1-thioglycerol CAS number: 96-27-5; glycerol allyl ether CAS number: 123-34-2.

[0035] In the following embodiments, "parts" refers to parts by weight, and all raw materials mentioned above and used but not mentioned are commercially available.

[0036] Wherein, the cold-resistant plasticizer is cold-resistant plasticizer DOS, the antioxidant 1076 is antioxidant 1076; the antioxidant is antioxidant RD; the graphene is graphene oxide, and the boron nitride is hydroxylated boron nitride.

[0037] Example 1: The preparation method of the sealing material includes the following steps:

[0038] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene and stir evenly. Gradually add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85). Stir and react at 45℃ for 6 hours. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0039] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid to 125 parts of deionized water and stir evenly. Add 5 parts of activator and 1.15 parts of aminoacetonitrile. Stir at 45°C for 4 hours, distill under reduced pressure, wash and dry to obtain amino-polyethylene glycol-acetonitrile.

[0040] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene and stir evenly. Add 0.5 parts of palladium catalyst and stir at 110°C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution and stir at 65°C for 12 h under a nitrogen atmosphere. Use anhydrous ethanol to precipitate the rubber, wash, and dry to obtain modified nitrile rubber.

[0041] Step 2: Preparation of hydrogenated nitrile butadiene rubber sealing material:

[0042] S1: Weigh 15 parts of graphene and boron nitride at a mass ratio of 2:1 as nanocomposite fillers;

[0043] S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene was dispersed in tetrahydrofuran, 1-thioglycerol was added, the amount of 1-thioglycerol added was 25wt% of the boric acid intercalated graphene, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified graphene; (2) Boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated boron nitride; the boric acid intercalated boron nitride was dispersed in tetrahydrofuran, glycerol allyl ether was added, the amount of glycerol allyl ether added was 25wt% of the boric acid intercalated boron nitride, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified boron nitride;

[0044] S3: 100 parts of hydrogenated nitrile rubber (75 parts of base hydrogenated nitrile rubber, 25 parts of modified nitrile rubber) and 8 parts of methyl methacrylate were mixed at 110°C and 50 rpm for 10 minutes. Modified graphene and modified boron nitride prepared in step S2 were added and dispersed at 600W for 20 minutes. 4.5 parts of dicumyl peroxide, 0.5 parts of sulfur, 1.6 parts of triallyl isocyanate, 1.1 parts of stearic acid, 4.5 parts of zinc oxide, and 3.5 parts of functional additives (2.3 parts of cold-resistant plasticizer, 0.1 parts of antioxidant, and 1.1 parts of anti-aging agent) were mixed at 110°C and 50 rpm for 12 minutes. The mixture was then vulcanized at 175°C and 8 MPa for 20 minutes. After that, it was subjected to liquid nitrogen freeze-embrittlement treatment at -196°C for 2 hours, then restored to room temperature and vacuum dried to obtain hydrogenated nitrile rubber sealing material.

[0045] Example 2: The preparation method of the sealing material includes the following steps:

[0046] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene and stir evenly. Gradually add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85). Stir and react at 45℃ for 6 hours. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0047] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid to 125 parts of deionized water and stir evenly. Add 5 parts of activator and 1.15 parts of aminoacetonitrile. Stir at 45°C for 4 hours, distill under reduced pressure, wash and dry to obtain amino-polyethylene glycol-acetonitrile.

[0048] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene and stir evenly. Add 0.5 parts of palladium catalyst and stir at 110°C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution and stir at 65°C for 12 h under a nitrogen atmosphere. Use anhydrous ethanol to precipitate the rubber, wash, and dry to obtain modified nitrile rubber.

[0049] Step 2: Preparation of hydrogenated nitrile butadiene rubber sealing material:

[0050] S1: Weigh 12 parts of graphene and boron nitride at a mass ratio of 2:1 as nanocomposite fillers;

[0051] S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene was dispersed in tetrahydrofuran, 1-thioglycerol was added, the amount of 1-thioglycerol added was 25wt% of the boric acid intercalated graphene, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified graphene; (2) Boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated boron nitride; the boric acid intercalated boron nitride was dispersed in tetrahydrofuran, glycerol allyl ether was added, the amount of glycerol allyl ether added was 25wt% of the boric acid intercalated boron nitride, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified boron nitride;

[0052] S3: 100 parts of hydrogenated nitrile rubber (70 parts of base hydrogenated nitrile rubber, 30 parts of modified nitrile rubber) and 6 parts of methyl methacrylate were mixed at 110°C and 50 rpm for 10 minutes. Modified graphene and modified boron nitride prepared in step S2 were added and dispersed at 600W for 20 minutes. 3.5 parts of dicumyl peroxide, 0.5 parts of sulfur, 1.5 parts of triallyl isocyanate, 1 part of stearic acid, 4 parts of zinc oxide, and 3.1 parts of functional additives (2 parts of cold-resistant plasticizer, 0.1 parts of antioxidant, and 1 part of anti-aging agent) were added and mixed at 110°C and 50 rpm for 12 minutes. The mixture was then vulcanized at 175°C and 8 MPa for 20 minutes. After that, it was subjected to liquid nitrogen freeze-embrittlement treatment at -196°C for 2 hours, then restored to room temperature and vacuum dried to obtain hydrogenated nitrile rubber sealing material.

[0053] Example 3: The preparation method of the sealing material includes the following steps:

[0054] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene and stir evenly. Gradually add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85). Stir and react at 45℃ for 6 hours. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0055] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid to 125 parts of deionized water and stir evenly. Add 5 parts of activator and 1.15 parts of aminoacetonitrile. Stir at 45°C for 4 hours, distill under reduced pressure, wash and dry to obtain amino-polyethylene glycol-acetonitrile.

[0056] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene and stir evenly. Add 0.5 parts of palladium catalyst and stir at 110°C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution and stir at 65°C for 12 h under a nitrogen atmosphere. Use anhydrous ethanol to precipitate the rubber, wash, and dry to obtain modified nitrile rubber.

[0057] Step 2: Preparation of hydrogenated nitrile butadiene rubber sealing material:

[0058] S1: Weigh 18 parts of graphene and boron nitride at a mass ratio of 2:1 as nanocomposite fillers;

[0059] S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene was dispersed in tetrahydrofuran, 1-thioglycerol was added, the amount of 1-thioglycerol added was 25wt% of the boric acid intercalated graphene, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified graphene; (2) Boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated boron nitride; the boric acid intercalated boron nitride was dispersed in tetrahydrofuran, glycerol allyl ether was added, the amount of glycerol allyl ether added was 25wt% of the boric acid intercalated boron nitride, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified boron nitride;

[0060] S3: 100 parts of hydrogenated nitrile butadiene rubber (80 parts of base hydrogenated nitrile butadiene rubber, 20 parts of modified nitrile butadiene rubber) and 10 parts of methyl methacrylate were mixed at 110°C and 50 rpm for 10 minutes. Modified graphene and modified boron nitride prepared in step S2 were added and dispersed at 600W for 20 minutes. 5 parts of dicumyl peroxide, 1 part of sulfur, 1.8 parts of triallyl isocyanate, 1.2 parts of stearic acid, 5 parts of zinc oxide, and 4.1 parts of functional additives (2.6 parts of cold-resistant plasticizer, 0.2 parts of antioxidant, and 1.3 parts of anti-aging agent) were mixed at 110°C and 50 rpm for 12 minutes. The mixture was then vulcanized at 175°C and 8 MPa for 20 minutes. After that, it was subjected to liquid nitrogen freeze-embrittlement treatment at -196°C for 2 hours, then restored to room temperature and vacuum dried to obtain hydrogenated nitrile butadiene rubber sealing material.

[0061] Comparative Example 1: Based on Example 1, the low-temperature embrittlement treatment was not performed, and the remaining processes remained unchanged, as follows:

[0062] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene and stir evenly. Gradually add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85). Stir and react at 45℃ for 6 hours. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0063] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid to 125 parts of deionized water and stir evenly. Add 5 parts of activator and 1.15 parts of aminoacetonitrile. Stir at 45°C for 4 hours, distill under reduced pressure, wash and dry to obtain amino-polyethylene glycol-acetonitrile.

[0064] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene and stir evenly. Add 0.5 parts of palladium catalyst and stir at 110°C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution and stir at 65°C for 12 h under a nitrogen atmosphere. Use anhydrous ethanol to precipitate the rubber, wash, and dry to obtain modified nitrile rubber.

[0065] Step 2: Preparation of hydrogenated nitrile butadiene rubber sealing material:

[0066] S1: Weigh 15 parts of graphene and boron nitride at a mass ratio of 2:1 as nanocomposite fillers;

[0067] S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene was dispersed in tetrahydrofuran, 1-thioglycerol was added, the amount of 1-thioglycerol added was 25wt% of the boric acid intercalated graphene, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified graphene; (2) Boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated boron nitride; the boric acid intercalated boron nitride was dispersed in tetrahydrofuran, glycerol allyl ether was added, the amount of glycerol allyl ether added was 25wt% of the boric acid intercalated boron nitride, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified boron nitride;

[0068] S3: 100 parts of hydrogenated nitrile butadiene rubber (75 parts of base hydrogenated nitrile butadiene rubber, 25 parts of modified nitrile butadiene rubber) and 8 parts of methyl methacrylate were mixed at 110°C and 50 rpm for 10 minutes. Modified graphene and modified boron nitride prepared in step S2 were added and dispersed at 600W for 20 minutes. 4.5 parts of dicumyl peroxide, 0.5 parts of sulfur, 1.6 parts of triallyl isocyanate, 1.1 parts of stearic acid, 4.5 parts of zinc oxide, and 3.5 parts of functional additives (2.3 parts of cold-resistant plasticizer, 0.1 parts of antioxidant, and 1.1 parts of anti-aging agent) were added and mixed at 110°C and 50 rpm for 12 minutes. The mixture was then vulcanized at 175°C and 8 MPa for 20 minutes and vacuum dried to obtain hydrogenated nitrile butadiene rubber sealing material.

[0069] Comparative Example 2: Based on Example 1, the molecular weight of amino-polyethylene glycol-carboxylic acid was increased to 3000, while the rest of the process remained unchanged, as follows:

[0070] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene and stir evenly. Gradually add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85). Stir and react at 45℃ for 6 hours. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0071] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid (molecular weight 3000) to 125 parts of deionized water and stir evenly. Add 5 parts of activator and 1.15 parts of aminoacetonitrile. Stir at 45°C for 4 hours, distill under reduced pressure, wash and dry to obtain amino-polyethylene glycol-acetonitrile.

[0072] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene and stir evenly. Add 0.5 parts of palladium catalyst and stir at 110°C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution and stir at 65°C for 12 h under a nitrogen atmosphere. Use anhydrous ethanol to precipitate the rubber, wash, and dry to obtain modified nitrile rubber.

[0073] Step 2: Preparation of hydrogenated nitrile butadiene rubber sealing material:

[0074] S1: Weigh 15 parts of graphene and boron nitride at a mass ratio of 2:1 as nanocomposite fillers;

[0075] S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene was dispersed in tetrahydrofuran, 1-thioglycerol was added, the amount of 1-thioglycerol added was 25wt% of the boric acid intercalated graphene, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified graphene; (2) Boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated boron nitride; the boric acid intercalated boron nitride was dispersed in tetrahydrofuran, glycerol allyl ether was added, the amount of glycerol allyl ether added was 25wt% of the boric acid intercalated boron nitride, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified boron nitride;

[0076] S3: 100 parts of hydrogenated nitrile rubber (75 parts of base hydrogenated nitrile rubber, 25 parts of modified nitrile rubber) and 8 parts of methyl methacrylate were mixed at 110°C and 50 rpm for 10 minutes. Modified graphene and modified boron nitride prepared in step S2 were added and dispersed at 600W for 20 minutes. 4.5 parts of dicumyl peroxide, 0.5 parts of sulfur, 1.6 parts of triallyl isocyanate, 1.1 parts of stearic acid, 4.5 parts of zinc oxide, and 3.5 parts of functional additives (2.3 parts of cold-resistant plasticizer, 0.1 parts of antioxidant, and 1.1 parts of anti-aging agent) were mixed at 110°C and 50 rpm for 12 minutes. The mixture was then vulcanized at 175°C and 8 MPa for 20 minutes. After that, it was subjected to liquid nitrogen freeze-embrittlement treatment at -196°C for 2 hours, then restored to room temperature and vacuum dried to obtain hydrogenated nitrile rubber sealing material.

[0077] Comparative Example 3: Based on Example 1, without the addition of modified nitrile rubber; the remaining processes remain unchanged, as follows:

[0078] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene and stir evenly. Gradually add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85). Stir and react at 45℃ for 6 hours. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0079] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid to 125 parts of deionized water and stir evenly. Add 5 parts of activator and 1.15 parts of aminoacetonitrile. Stir at 45°C for 4 hours, distill under reduced pressure, wash and dry to obtain amino-polyethylene glycol-acetonitrile.

[0080] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene and stir evenly. Add 0.5 parts of palladium catalyst and stir at 110°C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution and stir at 65°C for 12 h under a nitrogen atmosphere. Use anhydrous ethanol to precipitate the rubber, wash, and dry to obtain modified nitrile rubber.

[0081] Step 2: Preparation of hydrogenated nitrile butadiene rubber sealing material:

[0082] S1: Weigh 15 parts of graphene and boron nitride at a mass ratio of 2:1 as nanocomposite fillers;

[0083] S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene was dispersed in tetrahydrofuran, 1-thioglycerol was added, the amount of 1-thioglycerol added was 25wt% of the boric acid intercalated graphene, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified graphene; (2) Boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.5 were added to deionized water, wet-milled for 2 hours, filtered and dried to obtain boric acid intercalated boron nitride; the boric acid intercalated boron nitride was dispersed in tetrahydrofuran, glycerol allyl ether was added, the amount of glycerol allyl ether added was 25wt% of the boric acid intercalated boron nitride, stirred at 25°C for 24 hours, filtered, washed and dried to obtain modified boron nitride;

[0084] S3: 100 parts of hydrogenated nitrile butadiene rubber (100 parts of base hydrogenated nitrile butadiene rubber) and 8 parts of methyl methacrylate were mixed at 110°C and 50 rpm for 10 minutes. Modified graphene and modified boron nitride prepared in step S2 were added and dispersed at 600W for 20 minutes. 4.5 parts of dicumyl peroxide, 0.5 parts of sulfur, 1.6 parts of triallyl isocyanate, 1.1 parts of stearic acid, 4.5 parts of zinc oxide, and 3.5 parts of functional additives (2.3 parts of cold-resistant plasticizer, 0.1 parts of antioxidant, and 1.1 parts of anti-aging agent) were added and mixed at 110°C and 50 rpm for 12 minutes. The mixture was then vulcanized at 175°C and 8 MPa for 20 minutes. After that, it was subjected to liquid nitrogen freeze-embrittlement treatment at -196°C for 2 hours, then restored to room temperature and vacuum dried to obtain hydrogenated nitrile butadiene rubber sealing material.

[0085] Comparative Example 4: Based on Example 1, the modified graphene and modified boron nitride were replaced with commercially available graphene oxide and hydroxylated boron nitride, respectively, while the remaining processes remained unchanged, as follows:

[0086] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene and stir evenly. Gradually add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85). Stir and react at 45℃ for 6 hours. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber.

[0087] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid to 125 parts of deionized water and stir evenly. Add 5 parts of activator and 1.15 parts of aminoacetonitrile. Stir at 45°C for 4 hours, distill under reduced pressure, wash and dry to obtain amino-polyethylene glycol-acetonitrile.

[0088] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene and stir evenly. Add 0.5 parts of palladium catalyst and stir at 110°C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution and stir at 65°C for 12 h under a nitrogen atmosphere. Use anhydrous ethanol to precipitate the rubber, wash, and dry to obtain modified nitrile rubber.

[0089] Step 2: Preparation of hydrogenated nitrile butadiene rubber sealing material:

[0090] S1: Weigh 15 parts of graphene oxide and hydroxylated boron nitride at a mass ratio of 2:1 to serve as nanocomposite fillers;

[0091] S2: 100 parts of hydrogenated nitrile rubber and 8 parts of methyl methacrylate were mixed at 110°C and 50 rpm for 10 minutes. Graphene oxide and hydroxylated boron nitride were added and dispersed at 600W for 20 minutes. 4.5 parts of dicumyl peroxide, 0.5 parts of sulfur, 1.6 parts of triallyl isocyanate, 1.1 parts of stearic acid, 4.5 parts of zinc oxide, and 3.5 parts of functional additives (2.3 parts of cold-resistant plasticizer, 0.1 parts of antioxidant, and 1.1 parts of anti-aging agent) were added and mixed at 110°C and 50 rpm for 12 minutes. The mixture was then vulcanized at 175°C and 8 MPa for 20 minutes. After that, it was subjected to liquid nitrogen freeze-embrittlement treatment at -196°C for 2 hours, then restored to room temperature and vacuum dried to obtain hydrogenated nitrile rubber sealing material.

[0092] Performance Test 1: The hydrogenated nitrile rubber sealing materials prepared in each embodiment and comparative example were subjected to relevant performance tests; (1) High temperature stability: After measuring the tensile strength of the sample according to GB / T528, the sample was placed at 150℃ for 1000h, taken out, and the tensile strength was measured again to calculate the tensile strength retention rate; (2) Low temperature elasticity: The sample was placed at -46℃ and the elongation at break was measured according to GB / T528; The obtained data are shown in the table below:

[0093]

[0094] Conclusion: As shown in the table above, this application effectively constructs a hydrogenated nitrile rubber sealing material with high-temperature stability and low-temperature elasticity by introducing modified nitrile rubber into the hydrogenated nitrile rubber matrix and introducing methyl methacrylate as a copolymer modifier, further synergizing with a specific ratio of graphene and boron nitride, and correspondingly modifying it. In Comparative Example 1, no low-temperature embrittlement treatment was performed, resulting in stress concentration in the material and a decrease in material strength and tensile properties. In Comparative Example 2, increasing the molecular weight of amino-polyethylene glycol-carboxylic acid made it difficult for the side chains to disperse evenly in the matrix, leading to decreased interfacial properties and a decrease in elongation and other related properties. In Comparative Example 3, no modified nitrile rubber was added, resulting in a significant decrease in low-temperature elongation. In Comparative Example 4, modified graphene and modified boron nitride were replaced with commercially available graphene oxide and hydroxy boron nitride, respectively. Although this could reduce agglomeration and improve dispersibility to some extent, it was obviously not as good as Example 1, and the thermal management network capability of the component was not as good as that of the boric acid intercalation method, resulting in a decrease in related properties.

[0095] Performance Test 2: The hydrogenated nitrile rubber sealing material prepared in Example 1 was subjected to other performance tests, including wide temperature range performance, anti-gas explosion performance and dynamic fatigue performance.

[0096] Conclusion: In terms of wide temperature range performance, it can operate stably for extended periods within a temperature range of -46℃ to 150℃; in terms of anti-explosion performance, the critical pressure is >16MPa; and in terms of dynamic fatigue, the number of cycles is >150,000. This indicates that hydrogenated nitrile butadiene rubber sealing materials possess excellent temperature range, anti-explosion performance, and fatigue resistance.

[0097] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile butadiene rubber sealing material, characterized in that: Includes the following steps: S1: Weigh out graphene and boron nitride according to the mass ratio to use as nanocomposite fillers; S2: Hydrogenated nitrile butadiene rubber and methyl methacrylate are mixed in an internal mixer; nanocomposite filler is added and ultrasonically dispersed; gradient crosslinking agent and functional additives are added and mixed in an internal mixer for a second time; plate vulcanization is performed; post-treatment is carried out; room temperature recovery and vacuum drying are performed to obtain hydrogenated nitrile butadiene rubber sealing material. The hydrogenated nitrile butadiene rubber sealing material comprises the following raw materials, by weight: 100 parts hydrogenated nitrile butadiene rubber, 6-10 parts methyl methacrylate, 12-18 parts nanocomposite filler, 4-6 parts gradient crosslinking agent, and 3-5 parts functional additives. The nanocomposite filler comprises graphene and boron nitride in a mass ratio of 2:1; the gradient crosslinking agent is composed of peroxide and sulfur; and the functional additives include one or more of cold-resistant plasticizers, antioxidants, and anti-aging agents. The post-treatment is liquid nitrogen cryogenic embrittlement treatment, with the following process parameters: treatment at -200~-190℃ for 2~3 hours; The hydrogenated nitrile butadiene rubber includes a base hydrogenated nitrile butadiene rubber and a modified nitrile butadiene rubber in a mass ratio of 7~8:2~3. The modified nitrile butadiene rubber is obtained by epoxidizing part of the carbon-carbon double bonds of nitrile butadiene rubber through a mixed solution of formic acid and hydrogen peroxide, followed by hydrogenation treatment. Then, amino-polyethylene glycol-carboxylic acid is grafted onto aminoacetonitrile to obtain amino-polyethylene glycol-acetonitrile, which is then reacted with the epoxy groups in the epoxidized nitrile butadiene rubber to obtain modified nitrile butadiene rubber containing polyethylene glycol side chains.

2. The method for preparing a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile butadiene rubber sealing material according to claim 1, characterized in that: The modified nitrile rubber is prepared by: (1) Add nitrile rubber to chlorobenzene and stir evenly. Gradually add a mixed solution of formic acid and hydrogen peroxide. Stir and react at 40~45℃ for 6~8h. Precipitate the rubber with anhydrous ethanol, wash and dry to obtain epoxidized nitrile rubber. (2) Add amino-polyethylene glycol-carboxylic acid to deionized water and stir evenly. Add activator and aminoacetonitrile, stir at 40~50℃ for 3~4h, distill under reduced pressure, wash, and dry to obtain amino-polyethylene glycol-acetonitrile; (3) Add epoxidized nitrile rubber to chlorobenzene and stir evenly. Add palladium catalyst and stir at 100-120℃ for 2-3 hours under hydrogen pressure of 3-5 MPa. After exhausting the gas, obtain the adhesive solution. Add amino-polyethylene glycol-acetonitrile and potassium hydroxide to the adhesive solution and stir at 60-70℃ for 10-12 hours under nitrogen atmosphere. Use anhydrous ethanol to precipitate the adhesive, wash and dry to obtain modified nitrile rubber.

3. The method for preparing a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile butadiene rubber sealing material according to claim 2, characterized in that: The epoxidized nitrile rubber comprises the following raw materials, by weight: 8-10 parts nitrile rubber, 100 parts chlorobenzene, 1.4-1.6 parts a mixed solution of formic acid and hydrogen peroxide; the mass ratio of formic acid to hydrogen peroxide is 0.65:0.75-0.95; The amino-polyethylene glycol-acetonitrile comprises the following raw materials, by weight: 20-22 parts amino-polyethylene glycol-carboxylic acid, 4-6 parts activator, and 1.1-1.2 parts aminoacetonitrile; The modified nitrile rubber comprises the following raw materials, by weight: 8-10 parts epoxidized nitrile rubber, 100 parts chlorobenzene, 0.5-1 parts palladium catalyst, 25-30 parts amino-polyethylene glycol-acetonitrile, and 3-4 parts potassium hydroxide.

4. The method for preparing a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile butadiene rubber sealing material according to claim 2, characterized in that: The molecular weight of the amino-polyethylene glycol-carboxylic acid is 1000~1500.

5. The method for preparing a wide-temperature-range, gas-explosion-resistant hydrogenated nitrile butadiene rubber sealing material according to claim 1, characterized in that: The hydrogenated nitrile rubber sealing material also includes the following raw materials, by weight: 1.5-1.8 parts triallyl isocyanate, 1-1.2 parts stearic acid, and 4-5 parts zinc oxide.

6. The method for preparing a wide-temperature-range anti-gas-explosion hydrogenated nitrile rubber sealing material according to claim 1, characterized in that: The process parameters for the first internal mixing are: mixing at 105~115℃ and a speed of 30~50 rpm for 8~10 minutes; the process parameters for the ultrasonic dispersion are: dispersing at a power of 500~700W for 10~30 minutes; the process parameters for the second internal mixing are: mixing at 105~115℃ and a speed of 50~60 rpm for 10~12 minutes; the process parameters for the flat vulcanization are: vulcanizing at 170~180℃ and a pressure of 6~8 MPa for 15~25 minutes.

7. The method for preparing a wide-temperature-range anti-gas-explosion hydrogenated nitrile rubber sealing material according to claim 1, characterized in that: The pretreatment of graphene and boron nitride specifically includes the following steps: S1: Weigh out graphene and boron nitride according to the mass ratio to use as nanocomposite fillers; S2: (1) Graphene and 1,4-phenylenediboric acid in a mass ratio of 1:0.4~0.6 are added to deionized water, wet-milled for 1~2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene is dispersed in tetrahydrofuran, 1-thioglycerol is added, the amount of 1-thioglycerol added is 20~30wt% of the boric acid intercalated graphene, stirred at 25℃ for 24 hours, filtered, washed and dried to obtain modified graphite. (2) Add boron nitride and 1,4-phenylenediboric acid in a mass ratio of 1:0.4~0.6 to deionized water, wet grind for 1~2 hours, filter and dry to obtain boron nitride with boric acid; disperse boron nitride with boric acid in tetrahydrofuran, add glycerol allyl ether, the amount of glycerol allyl ether added is 20~30wt% of boron nitride with boric acid, stir at 25°C for 24 hours, filter, wash and dry to obtain modified boron nitride; S3: Hydrogenated nitrile butadiene rubber and methyl methacrylate are mixed once; modified graphene and modified boron nitride are added and ultrasonically dispersed; gradient crosslinking agent and functional additives are added and mixed a second time; plate vulcanization is performed; post-treatment is carried out; room temperature recovery and vacuum drying are performed to obtain hydrogenated nitrile butadiene rubber sealing material.

8. The wide-temperature-range resistant hydrogenated nitrile butadiene rubber sealing material prepared by the preparation method of the wide-temperature-range resistant hydrogenated nitrile butadiene rubber sealing material according to any one of claims 1 to 7.

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