Wide-temperature-range anti-gas-explosion hydrogenated nitrile rubber sealing material and preparation method thereof

Abstract

The invention discloses a wide-temperature-range anti-gas-explosion hydrogenated nitrile rubber sealing material and a preparation method thereof, and relates to the technical field of rubber. The hydrogenated butadiene-acrylonitrile rubber sealing material is prepared from the following raw materials in parts by mass: 100 parts of hydrogenated butadiene-acrylonitrile rubber, 6 to 10 parts of methyl methacrylate, 12 to 18 parts of nano composite filler, 4 to 6 parts of gradient cross-linking agent and 3 to 5 parts of functional additive. The nano composite material comprises graphene and boron nitride in a mass ratio of 2: 1; the gradient cross-linking agent is composed of peroxide and sulfur; the functional additive comprises one or more of a cold-resistant plasticizer, an antioxidant and an anti-aging agent. The hydrogenated butadiene-acrylonitrile rubber sealing material disclosed by the invention has excellent high-temperature stability and low-temperature elasticity, also has good gas explosion resistance, and is convenient for practical application.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber, and specifically to a hydrogenated nitrile rubber sealing material with wide temperature range and explosion resistance and its preparation method. Background Art

[0002] Hydrogenated nitrile rubber is a high-performance synthetic rubber prepared by hydrogenation reaction of nitrile rubber. It retains the advantages of good oil resistance of nitrile rubber, and at the same time has significant improvements in heat resistance, ozone resistance, chemical corrosion resistance and mechanical properties, etc. It is widely used in various fields, such as engine components and transmission system components of automobiles, and seals of oil extraction equipment.

[0003] However, in the prior art, the temperature adaptation range of hydrogenated nitrile rubber is relatively narrow, usually at -30~120°C, and its performance decreases significantly at some extreme temperatures. For example, when used at high temperature for a long time, the cross-linking bonds in the rubber break, resulting in a decrease in tensile strength, and when used at low temperature, the movement of molecular chain segments is hindered, resulting in hardening and a decrease in elongation rate, etc. There are defects of poor low-temperature elasticity; in another solution, when applied under high pressure, the explosion critical pressure is relatively low, generally less than 8 MPa, which is difficult to meet the use standards.

[0004] In summary, to solve the above problems, it is of great significance to prepare a hydrogenated nitrile rubber sealing material with wide temperature range and explosion resistance. Summary of the Invention

[0005] The purpose of the present invention is to provide a hydrogenated nitrile rubber sealing material with wide temperature range and explosion resistance and its preparation method to solve the problems raised in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A hydrogenated nitrile rubber sealing material with wide temperature range and explosion resistance, the hydrogenated nitrile rubber sealing material comprises the following raw materials by mass: 100 parts of hydrogenated nitrile rubber, 6~10 parts of methyl methacrylate, 12~18 parts of nano composite filler, 4~6 parts of gradient cross-linking agent, 3~5 parts of functional auxiliary agent.

[0008] Preferably, the nano composite material comprises graphene and boron nitride with a mass ratio of 2:1; the gradient cross-linking agent consists of peroxide and sulfur; the functional auxiliary agent includes one or more of cold-resistant plasticizer, antioxidant and anti-aging agent.

[0009] Preferably, the hydrogenated nitrile rubber comprises basic hydrogenated nitrile rubber and modified nitrile rubber with a mass ratio of 7~8:2~3.

[0010] Preferably, the preparation method of the modified nitrile rubber is as follows:

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

[0012] (2) Add amino - polyethylene glycol - carboxylic acid to deionized water and stir evenly. Add an activator and aminoacetonitrile, and stir at 40 - 50 °C for 3 - 4 h. 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 a palladium catalyst, and stir at 100 - 120 °C under a hydrogen pressure of 3 - 5 MPa for 2 - 3 h. After exhausting the gas, obtain a rubber solution. Add amino - polyethylene glycol - acetonitrile and potassium hydroxide to the rubber solution, and stir at 60 - 70 °C for 10 - 12 h under a nitrogen atmosphere. Precipitate the rubber with absolute ethanol, wash, and dry to obtain modified nitrile rubber.

[0014] More preferably, the epoxidized nitrile rubber comprises the following raw materials by mass parts: 8 - 10 parts of nitrile rubber, 100 parts of chlorobenzene, 1.4 - 1.6 parts of 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 mass parts: 20 - 22 parts of amino - polyethylene glycol - carboxylic acid, 4 - 6 parts of an activator, 1.1 - 1.2 parts of aminoacetonitrile.

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

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

[0018] More preferably, the hydrogenated nitrile rubber sealing material further comprises the following raw materials by mass parts: 1.5 - 1.8 parts of triallyl isocyanate, 1 - 1.2 parts of stearic acid, 4 - 5 parts of zinc oxide.

[0019] A preparation method of a hydrogenated nitrile rubber sealing material with wide - temperature - range anti - gas - explosion property, comprising the following steps:

[0020] S1: Weigh graphene and boron nitride according to a mass ratio as nano - composite fillers.

[0021] S2: First, conduct primary mixing of hydrogenated nitrile rubber and methyl methacrylate; add nano-composite fillers and disperse them by ultrasonic treatment; add gradient crosslinking agents and functional additives for secondary mixing, followed by flat vulcanization, post-treatment, room temperature recovery, and vacuum drying to obtain the hydrogenated nitrile rubber sealing material.

[0022] Preferably, the process parameters for the primary mixing are: at a temperature of 105 - 115°C and a rotation speed of 30 - 50 rpm, mix for 8 - 10 minutes; the process parameters for the ultrasonic dispersion are: disperse at a power of 500 - 700 W for 10 - 30 minutes; the process parameters for the secondary mixing are: at a temperature of 105 - 115°C and a rotation speed of 50 - 60 rpm, mix for 10 - 12 minutes; the process parameters for the flat vulcanization are: at a temperature of 170 - 180°C and a pressure of 6 - 8 MPa, vulcanize for 15 - 25 minutes.

[0023] The post-treatment is liquid nitrogen cryogenic embrittlement treatment, and the process parameters are: treat at -200 - -190°C for 2 - 3 hours.

[0024] Preferably, the graphene and boron nitride are pretreated, which specifically includes the following steps:

[0025] S1: Weigh graphene and boron nitride according to the mass ratio as nano-composite fillers.

[0026] S2: (1) Add graphene with a mass ratio of 1:0.4 - 0.6 and 1,4-benzenediboronic acid to deionized water in sequence, conduct wet grinding for 1 - 2 hours, filter and dry to obtain boric acid intercalated graphene; disperse the boric acid intercalated graphene in tetrahydrofuran, add 1-thioglycerol, and the addition amount of 1-thioglycerol accounts for 20 - 30 wt% of the boric acid intercalated graphene, stir at 25°C for 24 hours, filter, wash, and dry to obtain modified graphene; (2) Add boron nitride with a mass ratio of 1:0.4 - 0.6 and 1,4-benzenediboronic acid to deionized water in sequence, conduct wet grinding for 1 - 2 hours, filter and dry to obtain boric acid intercalated boron nitride; disperse the boric acid intercalated boron nitride in tetrahydrofuran, add allyl glycidyl ether, and the addition amount of allyl glycidyl ether accounts for 20 - 30 wt% of the boric acid intercalated boron nitride, stir at 25°C for 24 hours, filter, wash, and dry to obtain modified boron nitride.

[0027] S3: First, conduct primary mixing of hydrogenated nitrile rubber and methyl methacrylate; add modified graphene and modified boron nitride and disperse them by ultrasonic treatment; add gradient crosslinking agents and functional additives for secondary mixing, followed by flat vulcanization, post-treatment, room temperature recovery, and vacuum drying to obtain the hydrogenated nitrile rubber sealing material.

[0028] Compared with the prior art, the beneficial effects of the present application are as follows: In the solution, hydrogenated nitrile rubber is used as the main body, and methyl methacrylate is introduced as a copolymerization modifier to maintain the high and low temperature elongation while maintaining the strength; and a specific proportion of graphene and boron nitride are introduced as nano-composite fillers to construct a thermal management network, increasing 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 also carried out during the post-treatment process to eliminate internal stress concentration, thereby improving the high-temperature stability and low-temperature elasticity of the hydrogenated nitrile rubber sealing material, and thus promoting the improvement of the temperature range width and anti-gas explosion performance.

[0029] In a further solution, the modified nitrile rubber is compounded with the basic hydrogenated nitrile rubber to form the main hydrogenated nitrile rubber. By introducing the modified nitrile rubber and using its toughening side chains with a specific molecular weight grafted, the comprehensive performance is further improved.

[0030] The modified nitrile rubber is prepared by epoxidizing part of the carbon-carbon double bonds of nitrile rubber with a mixed solution of formic acid and hydrogen peroxide, followed by hydrogenation treatment to obtain epoxidized nitrile rubber, and then reacting with the epoxy groups in the epoxidized nitrile rubber after grafting amino-polyethylene glycol-carboxylic acid with aminoacetonitrile, thereby introducing polyethylene glycol side chains; compared with pure hydrogenated nitrile rubber, the present application introduces epoxy groups and grafts polyethylene glycol as side chains, which helps to improve the toughness of the rubber and the low-temperature performance, and introducing nitrile groups at the other end of polyethylene glycol is beneficial to improving the compatibility of the side chains in the rubber, thereby further improving the performance; at the same time, the amide bonds formed by grafting help to play a promoting role in the subsequent vulcanization process, thereby increasing the high-temperature stability and low-temperature elasticity of the material; however, the molecular weight of polyethylene glycol needs to be limited. When the molecular weight is too small, the toughening effect is limited, and when the molecular weight is too large, it is difficult to disperse evenly in the matrix, resulting in a decrease in performance.

[0031] Among them, introducing graphene and boron nitride with a mass ratio of 2:1 in nitrile rubber 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 heat to be transferred more efficiently, and as a reinforcing material, it can improve the comprehensive mechanical strength; however, their direct use has poor compatibility with the rubber material, so they are respectively modified to improve their dispersibility in the system and effectively maximize their reinforcement.

[0032] Among them, the modified graphene is obtained by intercalating boric acid and then grafting 1-thioglycerol to introduce mercapto groups; the modified boron nitride is also obtained by intercalating boric acid and then grafting allyl glycerol ether to introduce vinyl groups. After intercalating boric acid, on the one hand, the agglomeration of nano-fillers is avoided, and the dispersion of nano-fillers in the rubber matrix is improved; on the other hand, it helps the nano-fillers to further form a thermal management network and improve the high-temperature stability. The mercapto groups and vinyl groups introduced by the modified graphene and modified boron nitride respectively can undergo click reactions after heating to further form a thermal management network, further improving the high-temperature stability, low-temperature elasticity, and temperature wide range of the hydrogenated nitrile rubber sealing material. The two materials have a synergistic effect. Detailed implementation manners

[0033] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] It should be noted that there are no special restrictions on the purchasing manufacturers of all raw materials involved in the present invention. Exemplarily, they include: graphene with a sheet diameter of 0.5 - 5 μm; boron nitride with a particle size of 100 nm; 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; the CAS number of methyl methacrylate: 80-62-6; the CAS number of triallyl isocyanate: 1025-15-6; the CAS number of stearic acid: 57-11-4; the CAS number of 1,4-benzenediboronic acid: 4612-26-4; the CAS number of 1-thioglycerol: 96-27-5; the CAS number of allyl glycerol ether: 123-34-2.

[0035] Among them, in the following embodiments, "parts" refers to parts by mass, and all the above-mentioned raw materials used but not mentioned are commercially available.

[0036] Among them, the cold-resistant plasticizer is DOS, the antioxidant 1076 is antioxidant 1076; the anti-aging agent is anti-aging agent 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 drop 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (the mass ratio of the two is 0.65:0.85), and stir and react at 45°C for 6 h. Precipitate the rubber with absolute 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. Then add 5 parts of activator and 1.15 parts of aminoacetonitrile, stir at 45 °C for 4 h, perform vacuum distillation, 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. Then add 0.5 part of palladium catalyst, stir at 110 °C for 2.5 h under a hydrogen pressure of 4 MPa to obtain a glue solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the glue solution, stir at 65 °C for 12 h under a nitrogen atmosphere, precipitate the glue with absolute ethanol, wash, and dry to obtain modified nitrile rubber;

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

[0042] S1: Weigh 15 parts of graphene and boron nitride according to a mass ratio of 2:1 as nano-composite fillers;

[0043] S2: (1) Add graphene and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, perform wet grinding for 2 h, filter and dry to obtain boric acid intercalated graphene. Disperse the boric acid intercalated graphene in tetrahydrofuran, add 1-thioglycerol, and the addition amount of 1-thioglycerol accounts for 25 wt% of the boric acid intercalated graphene, stir at 25 °C for 24 h, filter, wash, and dry to obtain modified graphene. (2) Add boron nitride and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, perform wet grinding for 2 h, filter and dry to obtain boric acid intercalated boron nitride. Disperse the boric acid intercalated boron nitride in tetrahydrofuran, add allyl glycidyl ether, and the addition amount of allyl glycidyl ether accounts for 25 wt% of the boric acid intercalated boron nitride, stir at 25 °C for 24 h, filter, wash, and dry to obtain modified boron nitride;

[0044] S3: Add 100 parts of hydrogenated nitrile rubber (75 parts of basic hydrogenated nitrile rubber, 25 parts of modified nitrile rubber) and 8 parts of methyl methacrylate, perform primary internal mixing at 110 °C at a rotation speed of 50 rpm for 10 minutes; add the modified graphene and modified boron nitride prepared in step S2 and disperse at a power of 600 W for 20 minutes; add 4.5 parts of dicumyl peroxide, 0.5 part of sulfur, 1.6 parts of triallyl isocyanate, 1.1 parts of stearic acid, 4.5 parts of zinc oxide, 3.5 parts of functional additives (2.3 parts of cold-resistant plasticizer, 0.1 part of antioxidant, 1.1 parts of anti-aging agent), perform secondary internal mixing at 110 °C at a rotation speed of 50 rpm for 12 minutes, vulcanize at 175 °C under a pressure of 8 MPa for 20 minutes, then perform liquid nitrogen freezing embrittlement treatment at -196 °C for 2 h, restore at room temperature and perform vacuum drying to obtain the hydrogenated nitrile rubber sealing material.

[0045] Example 2: The preparation method of the sealing material comprises 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 (the mass ratio of the two is 0.65:0.85). Stir and react at 45°C for 6 h. Precipitate the rubber with absolute 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 h. 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 part of palladium catalyst. 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. Stir at 65°C for 12 h under a nitrogen atmosphere. Precipitate the rubber with absolute ethanol, wash, and dry to obtain modified nitrile rubber;

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

[0050] S1: Weigh 12 parts of graphene and boron nitride according to a mass ratio of 2:1 as the nano-composite filler;

[0051] S2: (1) Add graphene and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, wet mill for 2 h, filter, and dry to obtain boric acid intercalated graphene. Disperse the boric acid intercalated graphene in tetrahydrofuran, add 1-thioglycerol, and the addition amount of 1-thioglycerol accounts for 25 wt% of the boric acid intercalated graphene. Stir at 25°C for 24 h, filter, wash, and dry to obtain modified graphene; (2) Add boron nitride and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, wet mill for 2 h, filter, and dry to obtain boric acid intercalated boron nitride. Disperse the boric acid intercalated boron nitride in tetrahydrofuran, add allyl glycerol ether, and the addition amount of allyl glycerol ether accounts for 25 wt% of the boric acid intercalated boron nitride. Stir at 25°C for 24 h, filter, wash, and dry to obtain modified boron nitride;

[0052] S3: Weigh 100 parts of hydrogenated nitrile rubber (70 parts of basic hydrogenated nitrile rubber and 30 parts of modified nitrile rubber), 6 parts of methyl methacrylate, and conduct primary internal mixing at 110°C for 10 minutes at a rotation speed of 50 rpm; add the modified graphene and modified boron nitride prepared in step S2 and disperse them at a power of 600 W for 20 minutes; add 3.5 parts of dicumyl peroxide, 0.5 part 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 part of antioxidant, 1 part of anti-aging agent), and conduct secondary internal mixing at 110°C for 12 minutes at a rotation speed of 50 rpm, then vulcanize at 175°C under a pressure of 8 MPa for 20 minutes, and then conduct liquid nitrogen freezing embrittlement treatment at -196°C for 2 hours, restore to room temperature and conduct vacuum drying to obtain the 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, stir evenly, gradually dropwise add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (the mass ratio of the two is 0.65:0.85), stir and react at 45°C for 6 h, precipitate the rubber with absolute 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, stir evenly, add 5 parts of activator and 1.15 parts of aminoacetonitrile, stir at 45°C for 4 h, conduct reduced-pressure distillation, wash, and dry to obtain amino-polyethylene glycol-acetonitrile;

[0056] (3) Add 9 parts of epoxidized nitrile rubber to 100 parts of chlorobenzene, stir evenly, add 0.5 part 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, stir at 65°C for 12 h under a nitrogen atmosphere, precipitate the rubber with absolute ethanol, wash, and dry to obtain modified nitrile rubber;

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

[0058] S1: Weigh 18 parts of graphene and boron nitride according to a mass ratio of 2:1 as the nano-composite filler;

[0059] S2: (1) Graphene and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 are successively added to deionized water, wet milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene. The boric acid intercalated graphene is dispersed in tetrahydrofuran, and 1-thioglycerol is added. The addition amount of 1-thioglycerol accounts for 25 wt% of the boric acid intercalated graphene. Stir at 25 °C for 24 hours, filter, wash and dry to obtain modified graphene. (2) Boron nitride and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 are successively 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 is dispersed in tetrahydrofuran, and allyl glycidyl ether is added. The addition amount of allyl glycidyl ether accounts for 25 wt% of the boric acid intercalated boron nitride. Stir at 25 °C for 24 hours, filter, wash and dry to obtain modified boron nitride.

[0060] S3: 100 parts of hydrogenated nitrile rubber (80 parts of basic hydrogenated nitrile rubber, 20 parts of modified nitrile rubber) and 10 parts of methyl methacrylate are subjected to primary internal mixing at 110 °C at a rotation speed of 50 rpm for 10 minutes. The modified graphene and modified boron nitride prepared in step S2 are added and dispersed at a power of 600 W 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 part of antioxidant, 1.3 parts of anti-aging agent) are added and subjected to secondary internal mixing at 110 °C at a rotation speed of 50 rpm for 12 minutes, vulcanized at 175 °C under a pressure of 8 MPa for 20 minutes, then cryogenically embrittled at -196 °C for 2 hours, restored to room temperature and vacuum dried to obtain a hydrogenated nitrile rubber sealing material.

[0061] Comparative Example 1: Based on Example 1, no low-temperature embrittlement treatment is carried out, and the rest of the processes remain unchanged. Specifically as follows:

[0062] (1) 9 parts of nitrile rubber are added to 100 parts of chlorobenzene and stirred evenly. A mixed solution of 1.5 parts of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85) is gradually added dropwise, and the reaction is stirred at 45 °C for 6 h. The rubber is precipitated with absolute ethanol, washed and dried to obtain epoxidized nitrile rubber.

[0063] (2) 21 parts of amino-polyethylene glycol-carboxylic acid are added to 125 parts of deionized water and stirred evenly. 5 parts of activator and 1.15 parts of aminoacetonitrile are added, and the mixture is stirred at 45 °C for 4 h, followed by vacuum distillation, washing and drying 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 part 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, stir at 65 °C for 12 h under a nitrogen atmosphere, precipitate the rubber with absolute ethanol, wash, and dry to obtain modified nitrile rubber;

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

[0066] S1: Weigh 15 parts of graphene and boron nitride according to a mass ratio of 2:1 as nano-composite fillers;

[0067] S2: (1) Add graphene and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, wet mill for 2 h, filter, and dry to obtain boric acid intercalated graphene. Disperse the boric acid intercalated graphene in tetrahydrofuran, add 1-thioglycerol, and the addition amount of 1-thioglycerol accounts for 25 wt% of the boric acid intercalated graphene, stir at 25 °C for 24 h, filter, wash, and dry to obtain modified graphene; (2) Add boron nitride and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, wet mill for 2 h, filter, and dry to obtain boric acid intercalated boron nitride. Disperse the boric acid intercalated boron nitride in tetrahydrofuran, add glycerol allyl ether, and the addition amount of glycerol allyl ether accounts for 25 wt% of the boric acid intercalated boron nitride, stir at 25 °C for 24 h, filter, wash, and dry to obtain modified boron nitride;

[0068] S3: Add 100 parts of hydrogenated nitrile rubber (75 parts of basic hydrogenated nitrile rubber, 25 parts of modified nitrile rubber) and 8 parts of methyl methacrylate, mix them intensively at 110 °C at a speed of 50 rpm for 10 min; add the modified graphene and modified boron nitride prepared in step S2 and disperse them at a power of 600 W for 20 min; add 4.5 parts of dicumyl peroxide, 0.5 part of sulfur, 1.6 parts of triallyl isocyanate, 1.1 parts of stearic acid, 4.5 parts of zinc oxide, 3.5 parts of functional additives (2.3 parts of cold-resistant plasticizer, 0.1 part of antioxidant, 1.1 parts of anti-aging agent), mix them intensively at 110 °C at a speed of 50 rpm for 12 min, vulcanize at 175 °C under a pressure of 8 MPa for 20 min, and dry in vacuum to obtain hydrogenated nitrile rubber sealing material.

[0069] Comparative Example 2: Based on Example 1, increase the molecular weight of amino-polyethylene glycol-carboxylic acid to 3000, and keep the rest of the process unchanged. The details are 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 (the mass ratio of the two is 0.65:0.85). Stir and react at 45 °C for 6 h. Precipitate the rubber with absolute ethanol, wash, and dry to obtain epoxidized nitrile rubber;

[0071] (2) Add 21 parts of amino-polyethylene glycol-carboxylic acid (molecular weight of 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 h. 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 part of palladium catalyst. 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. Stir at 65 °C for 12 h under a nitrogen atmosphere. Precipitate the rubber with absolute ethanol, wash, and dry to obtain modified nitrile rubber;

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

[0074] S1: Weigh 15 parts of graphene and boron nitride according to a mass ratio of 2:1 as nano-composite fillers;

[0075] S2: (1) Add graphene and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, wet mill for 2 hours, filter, and dry to obtain boric acid intercalated graphene. Disperse the boric acid intercalated graphene in tetrahydrofuran, add 1-thioglycerol, and the addition amount of 1-thioglycerol accounts for 25 wt% of the boric acid intercalated graphene. Stir at 25 °C for 24 hours, filter, wash, and dry to obtain modified graphene; (2) Add boron nitride and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 to deionized water in sequence, wet mill for 2 hours, filter, and dry to obtain boric acid intercalated boron nitride. Disperse the boric acid intercalated boron nitride in tetrahydrofuran, add allyl glycerol ether, and the addition amount of allyl glycerol ether accounts for 25 wt% of the boric acid intercalated boron nitride. Stir at 25 °C for 24 hours, filter, wash, and dry to obtain modified boron nitride;

[0076] S3: Weigh 100 parts of hydrogenated nitrile rubber (75 parts of base hydrogenated nitrile rubber and 25 parts of modified nitrile rubber), 8 parts of methyl methacrylate, and carry out primary internal mixing at 110 °C with a rotation speed of 50 rpm for 10 minutes; add the modified graphene and modified boron nitride prepared in step S2 and disperse them at a power of 600 W for 20 minutes; add 4.5 parts of diisopropylbenzene peroxide, 0.5 part 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 part of antioxidant, 1.1 parts of anti-aging agent), and carry out secondary internal mixing at 110 °C with a rotation speed of 50 rpm for 12 minutes, vulcanize at 175 °C with a pressure of 8 MPa for 20 minutes, then carry out liquid nitrogen freezing embrittlement treatment at -196 °C for 2 hours, restore to room temperature, and carry out vacuum drying to obtain the hydrogenated nitrile rubber sealing material.

[0077] Comparative example 3: Based on Example 1, do not add modified nitrile rubber; the rest of the processes remain unchanged, specifically as follows:

[0078] (1) Add 9 parts of nitrile rubber to 100 parts of chlorobenzene, stir evenly, gradually dropwise add 1.5 parts of a mixed solution of formic acid and hydrogen peroxide (the mass ratio of the two is 0.65:0.85), stir and react at 45 °C for 6 h, precipitate the rubber with absolute 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, stir evenly, add 5 parts of activator and 1.15 parts of aminoacetonitrile, stir at 45 °C for 4 h, carry out vacuum distillation, wash, and dry to obtain amino-polyethylene glycol-acetonitrile;

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

[0081] Step two: Preparation of the hydrogenated nitrile rubber sealing material:

[0082] S1: Weigh 15 parts of graphene and boron nitride according to a mass ratio of 2:1 as the nano-composite filler;

[0083] S2: (1) Graphene and 1,4-benzenediboronic acid with a mass ratio of 1:0.5 are successively added to deionized water, wet milled for 2 hours, filtered and dried to obtain boric acid intercalated graphene; the boric acid intercalated graphene is dispersed in tetrahydrofuran, 1-thioglycerol is added, and the addition amount of 1-thioglycerol accounts for 25 wt% 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-benzenediboronic acid with a mass ratio of 1:0.5 are successively 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 is dispersed in tetrahydrofuran, allyl glycidyl ether is added, and the addition amount of allyl glycidyl ether accounts for 25 wt% 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 rubber (100 parts of basic hydrogenated nitrile rubber) and 8 parts of methyl methacrylate are first mixed in a kneader at 110 °C and a rotation speed of 50 rpm for 10 minutes; the modified graphene and modified boron nitride prepared in step S2 are added and dispersed at a power of 600 W for 20 minutes; 4.5 parts of dicumyl peroxide, 0.5 part of sulfur, 1.6 parts of triallyl isocyanurate, 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 part of antioxidant, 1.1 parts of anti-aging agent) are added and secondarily mixed in a kneader at 110 °C and a rotation speed of 50 rpm for 12 minutes, vulcanized at 175 °C and a pressure of 8 MPa for 20 minutes, then cryogenically embrittled by liquid nitrogen freezing at -196 °C for 2 hours, restored to room temperature and vacuum dried to obtain a hydrogenated nitrile rubber sealing material.

[0085] Comparative Example 4: Based on Example 1, the modified graphene and modified boron nitride are respectively replaced with commercially available graphene oxide and hydroxylated boron nitride, and the rest of the process remains unchanged, specifically as follows:

[0086] (1) 9 parts of nitrile rubber are added to 100 parts of chlorobenzene and stirred evenly, and a mixed solution of 1.5 parts of formic acid and hydrogen peroxide (mass ratio of the two is 0.65:0.85) is gradually added dropwise, stirred and reacted at 45 °C for 6 h, precipitated with absolute ethanol, washed and dried to obtain epoxidized nitrile rubber;

[0087] (2) 21 parts of amino-polyethylene glycol-carboxylic acid are added to 125 parts of deionized water and stirred evenly, 5 parts of activator and 1.15 parts of aminoacetonitrile are added, stirred at 45 °C for 4 h, distilled under reduced pressure, washed and dried 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 part of palladium catalyst. Under a hydrogen pressure of 4 MPa, stir at 110 °C for 2.5 h to obtain a rubber solution. Add 28 parts of amino-polyethylene glycol-acetonitrile and 3.5 parts of potassium hydroxide to the rubber solution. Stir at 65 °C for 12 h under a nitrogen atmosphere. Precipitate the rubber with absolute ethanol, wash, and dry to obtain modified nitrile rubber.

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

[0090] S1: Weigh 15 parts of graphene oxide and hydroxylated boron nitride according to a mass ratio of 2:1 as nano-composite fillers.

[0091] S2: Mix 100 parts of hydrogenated nitrile rubber and 8 parts of methyl methacrylate at 110 °C and a rotation speed of 50 rpm for the first stage of internal mixing for 10 minutes. Add graphene oxide and hydroxylated boron nitride and disperse at a power of 600 W for 20 minutes. Add 4.5 parts of dicumyl peroxide, 0.5 part 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 part of antioxidant, 1.1 parts of anti-aging agent) and conduct the second stage of internal mixing at 110 °C and a rotation speed of 50 rpm for 12 minutes. Cure at 175 °C and a pressure of 8 MPa for 20 minutes, then conduct liquid nitrogen freezing embrittlement treatment at -196 °C for 2 hours, restore to room temperature, and dry in vacuum to obtain the hydrogenated nitrile rubber sealing material.

[0092] Performance test 1: Conduct relevant performance tests on the hydrogenated nitrile rubber sealing materials prepared in each example and comparative example; (1) High-temperature stability: After measuring the tensile strength of the sample according to GB / T528, place the sample at 150 °C for 1000 h, take it out, measure the tensile strength again, and calculate the tensile strength retention rate; (2) Low-temperature elasticity: Place the sample at -46 °C for treatment, and measure the elongation at break according to GB / T528; the obtained data are shown in the following table:

[0093]

[0094] Conclusion: As can be seen from the above table, in this application, modified nitrile rubber is introduced into the hydrogenated nitrile rubber matrix, and methyl methacrylate is introduced as a copolymerization modifier. Further, graphene and boron nitride in a specific ratio are synergistically used and correspondingly modified to effectively construct a hydrogenated nitrile rubber sealing material with high-temperature stability and low-temperature elasticity. In Comparative Example 1, no low-temperature embrittlement treatment is carried out, stress concentration occurs in the material, and the material strength and tensile properties decrease; in Comparative Example 2, the molecular weight of amino-polyethylene glycol-carboxylic acid is increased, and the side chains are difficult to disperse evenly in the matrix, resulting in a decrease in interfacial properties and a decrease in elongation rate and other related properties; in Comparative Example 3, no modified nitrile rubber is added, and the low-temperature elongation rate is greatly reduced; in Comparative Example 4, modified graphene and modified boron nitride are respectively replaced by commercially available graphene oxide and hydroxyboron nitride. Although it can reduce agglomeration and improve dispersion to a certain extent, it is obviously inferior to Example 1, and its ability to construct a thermal management network is inferior to the boric acid intercalation method, and related properties decrease.

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

[0096] Conclusion: In terms of wide-temperature range performance, it can serve stably for a long time in the temperature range of -46°C to 150°C; in terms of anti-gas explosion performance, the critical pressure > 16 MPa; in dynamic fatigue, the number of cycles > 150,000 times. It shows that the hydrogenated nitrile rubber sealing material has excellent temperature range width, anti-gas explosion performance, and fatigue resistance.

[0097] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used 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 perform equivalent replacements on some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A hydrogenated nitrile rubber sealing material with wide temperature range resistance to gas explosion, characterized in that: The hydrogenated nitrile rubber sealing material comprises the following raw materials by mass: 100 parts of hydrogenated nitrile rubber, 6-10 parts of methyl methacrylate, 12-18 parts of nano-composite filler, 4-6 parts of gradient crosslinking agent, and 3-5 parts of functional additive.

2. The hydrogenated nitrile rubber sealing material with wide temperature range and anti-gas explosion according to claim 1, wherein: The nano-composite material comprises graphene and boron nitride with a mass ratio of 2:1; the gradient crosslinking agent consists of peroxide and sulfur; the functional additive includes one or more of cold-resistant plasticizer, antioxidant, and anti-aging agent.

3. The hydrogenated nitrile rubber sealing material with wide temperature range and anti-gas explosion resistance according to claim 1, characterized in that: The hydrogenated nitrile rubber comprises basic hydrogenated nitrile rubber and modified nitrile rubber with a mass ratio of 7-8:2-3.

4. The hydrogenated nitrile rubber sealing material with wide temperature range and anti-gas explosion according to claim 3, characterized in that: The preparation method of the modified nitrile rubber is as follows: (1) Add nitrile rubber into chlorobenzene and stir evenly. Gradually dropwise add the mixed solution of formic acid and hydrogen peroxide, and stir and react at 40-45 °C for 6-8 h. Precipitate the rubber with absolute ethanol, wash, and dry to obtain epoxidized nitrile rubber. (2) Add amino-polyethylene glycol-carboxylic acid into deionized water and stir evenly. Add an activator and aminoacetonitrile, and stir at 40-50 °C for 3-4 h. Carry out reduced-pressure distillation, wash, and dry to obtain amino-polyethylene glycol-acetonitrile. (3) Add epoxidized nitrile rubber into chlorobenzene and stir evenly. Add a palladium catalyst, and stir at 100-120 °C under a hydrogen pressure of 3-5 MPa for 2-3 h. After exhausting the gas, obtain a rubber solution. Add amino-polyethylene glycol-acetonitrile and potassium hydroxide into the rubber solution, and stir at 60-70 °C for 10-12 h under a nitrogen atmosphere. Precipitate the rubber with absolute ethanol, wash, and dry to obtain modified nitrile rubber.

5. The hydrogenated nitrile rubber sealing material with wide temperature range and anti-air explosion according to claim 4, characterized in that: The epoxidized nitrile rubber comprises the following raw materials by mass: 8-10 parts of nitrile rubber, 100 parts of chlorobenzene, 1.4-1.6 parts of the 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 mass: 20-22 parts of amino-polyethylene glycol-carboxylic acid, 4-6 parts of activator, and 1.1-1.2 parts of aminoacetonitrile. The modified nitrile rubber comprises the following raw materials by mass: 8-10 parts of epoxidized nitrile rubber, 100 parts of chlorobenzene, 0.5-1 part of palladium catalyst, 25-30 parts of amino-polyethylene glycol-acetonitrile, and 3-4 parts of potassium hydroxide.

6. The hydrogenated nitrile rubber sealing material with wide temperature range and anti-air explosion according to claim 5, characterized in that: The molecular weight of the amino-polyethylene glycol-carboxylic acid is 1000-1500.

7. The hydrogenated nitrile rubber sealing material with wide temperature range and anti-air explosion according to claim 1, characterized in that: The hydrogenated nitrile rubber sealing material further comprises the following raw materials by mass: 1.5-1.8 parts of triallyl isocyanate, 1-1.2 parts of stearic acid, and 4-5 parts of zinc oxide.

8. The preparation method of a hydrogenated nitrile rubber sealing material with wide temperature range and anti-air explosion according to any one of claims 1 to 7, characterized in that: It includes the following steps: S1: Weigh graphene and boron nitride according to the mass ratio as the nano-composite filler. S2: First, carry out one-stage internal mixing of hydrogenated nitrile rubber and methyl methacrylate; add the nano-composite filler for ultrasonic dispersion; add the gradient crosslinking agent and functional additive for second-stage internal mixing, carry out flat vulcanization, post-treatment, restore at room temperature, and vacuum dry to obtain the hydrogenated nitrile rubber sealing material.

9. The preparation method of a hydrogenated nitrile rubber sealing material with wide temperature range resistance to gas explosion according to claim 8, characterized in that: The process parameters of the first stage of internal mixing are as follows: internal mixing for 8 - 10 minutes at a temperature of 105 - 115°C and a rotational speed of 30 - 50 rpm; the process parameters of ultrasonic dispersion are as follows: dispersing for 10 - 30 minutes at a power of 500 - 700 W; the process parameters of the second stage of internal mixing are as follows: internal mixing for 10 - 12 minutes at a temperature of 105 - 115°C and a rotational speed of 50 - 60 rpm; the process parameters of flat vulcanization are as follows: vulcanizing for 15 - 25 minutes at a temperature of 170 - 180°C and a pressure of 6 - 8 MPa; The post - treatment is liquid nitrogen cryogenic embrittlement treatment, and the process parameters are as follows: treating for 2 - 3 hours at - 200~ - 190°C.

10. The preparation method of a hydrogenated nitrile rubber sealing material with wide temperature range and anti-air explosion according to claim 8, characterized in that: The graphene and boron nitride are pretreated, which specifically includes the following steps: S1: Weigh graphene and boron nitride according to the mass ratio as nano - composite fillers; S2: (1) Add graphene with a mass ratio of 1:0.4 - 0.6 and 1,4 - benzenediboronic acid to deionized water in sequence, wet - grind for 1 - 2 hours, filter and dry to obtain boric acid - intercalated graphene; disperse the boric acid - intercalated graphene in tetrahydrofuran, add 1 - thioglycerol, and the addition amount of 1 - thioglycerol accounts for 20 - 30 wt% of the boric acid - intercalated graphene, stir at 25°C for 24 hours, filter, wash and dry to obtain modified graphene; (2) Add boron nitride with a mass ratio of 1:0.4 - 0.6 and 1,4 - benzenediboronic acid to deionized water in sequence, wet - grind for 1 - 2 hours, filter and dry to obtain boric acid - intercalated boron nitride; disperse the boric acid - intercalated boron nitride in tetrahydrofuran, add allyl glycidyl ether, and the addition amount of allyl glycidyl ether accounts for 20 - 30 wt% of the boric acid - intercalated boron nitride, stir at 25°C for 24 hours, filter, wash and dry to obtain modified boron nitride; S3: First stage of internal mixing of hydrogenated nitrile rubber and methyl methacrylate; add modified graphene and modified boron nitride for ultrasonic dispersion; add gradient cross - linker and functional additives for the second stage of internal mixing, flat vulcanization, post - treatment, room - temperature recovery and vacuum drying to obtain the hydrogenated nitrile rubber sealing material.

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