A sealing material made of perfluoroether rubber and its preparation method

Abstract

This invention belongs to the field of rubber material technology, specifically proposing a perfluoroether rubber sealing material and its preparation method. The raw materials of the perfluoroether rubber sealing material, by weight, include: 100 parts of perfluoroether rubber raw rubber, 5-15 parts of amino graphene, 20-30 parts of carbon black, 1-3 parts of crosslinking agent, 0.5-2 parts of co-crosslinking agent, and 0-3 parts of processing aid. The perfluoroether rubber raw rubber is obtained by emulsion polymerization of tetrafluoroethylene, perfluoroalkyl vinyl ether, and aromatic aldehyde-containing fluorinated vinyl ether as comonomers under the conditions of vulcanization point monomers and chain transfer agents. This invention, through improving the interfacial interaction between graphene as a filler and the perfluoroether rubber matrix, enhances the dispersibility of graphene, thereby simultaneously improving high-temperature resistance, mechanical properties, and durability, significantly improving the sealing effect of the sealing material.

Description

Technical Field

[0001] This invention relates to the field of rubber materials technology, and in particular to a perfluoroether rubber sealing material and its preparation method. Background Technology

[0002] In recent years, research on perfluoroether rubber sealing materials has been conducted in fields such as semiconductor manufacturing, aerospace, and chemical equipment, resulting in the stable mass production of perfluoroether rubber and perfluoropolyether rubber. Compared to other rubbers, perfluoroether rubber is mainly used in various special media, exhibiting excellent resistance to high and low temperatures, media, and heat and oxygen aging. Sealing products made from perfluoroether rubber are widely used in high-temperature environments, propellant media, and sealing components requiring stable storage.

[0003] Perfluoroelastomer (PFE) rubber seals possess resistance to almost all media and high temperatures, and their ability to maintain elasticity and sealing performance at high temperatures far surpasses that of other elastomers. With the rapid development of industries such as semiconductor manufacturing, the requirements for processing equipment are becoming increasingly stringent. The PFE rubber materials used in sealing products not only need to have resistance to media, but also high-temperature resistance, mechanical properties, and durability.

[0004] To improve the aforementioned properties of perfluoroelastomer (PFE) rubber seals, adding fillers is a common method. Adding nanofillers such as nano-silica and carbon nanotubes to PFE rubber can increase the material's strength and hardness. However, the interfacial interaction between the filler and the rubber matrix is ​​weak, easily leading to stress concentration. Under stress, debonding can easily occur between the filler and the matrix, resulting in a significant decrease in performance. Furthermore, the dispersibility of the filler is also an issue. If the filler is not evenly dispersed in the rubber, it can create localized performance defects, reducing various properties of the material. Summary of the Invention

[0005] Based on the technical problems existing in the background technology, the present invention proposes a perfluoroether rubber sealing material and its preparation method. By improving the interfacial force between graphene as a filler and the perfluoroether rubber matrix, the dispersibility of graphene is improved, thereby simultaneously improving high temperature resistance, mechanical properties and durability, and significantly improving the sealing effect of the sealing material.

[0006] The present invention proposes a sealing material of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 5-15 parts of amino graphene, 20-30 parts of carbon black, 1-3 parts of crosslinking agent, 0.5-2 parts of co-crosslinking agent, and 0-3 parts of processing aid.

[0007] The perfluoroether rubber raw rubber is obtained by emulsion polymerization of tetrafluoroethylene, perfluoroalkyl vinyl ether and aromatic aldehyde fluorinated vinyl ether as comonomers under the conditions of vulcanization point monomer and chain transfer agent.

[0008] In this invention, the perfluoroether rubber raw material is obtained by using tetrafluoroethylene, perfluoroalkyl vinyl ether, and aromatic aldehyde-containing fluorinated vinyl ether as comonomers. Its molecular backbone contains aromatic aldehyde group reaction sites. On one hand, these aromatic aldehyde group reaction sites can undergo a Schiff base reaction with amino graphene to generate imine, thus allowing graphene to be chemically grafted into the perfluoroether rubber raw material molecular chain. This improves the interfacial interaction between graphene and the perfluoroether rubber matrix, significantly increasing the interfacial bonding energy and reducing stress concentration and debonding caused by weak interfacial interactions. It also fully leverages the effect of graphene in improving the high-temperature resistance, mechanical properties, and durability of the perfluoroether rubber material. On the other hand, aromatic aldehyde-containing fluorinated vinyl ether is a rigid monomer with high thermal and chemical stability. Its rigid structure can also restrict the movement of molecular chains, reducing relaxation at high temperatures. Therefore, by introducing aromatic aldehyde-containing fluorinated vinyl ether into the copolymerization process, the structure of the perfluoroether rubber is modified to further improve its high-temperature resistance and media resistance.

[0009] Preferably, the structural formula of the aromatic aldehyde-containing fluorinated vinyl ether is as follows: .

[0010] Preferably, the aromatic aldehyde-containing fluorinated vinyl ether is obtained by electrophilic substitution reaction of p-hydroxybenzaldehyde and 4-bromo-1,1,2-trifluoro-1-butene.

[0011] Preferably, the perfluoroalkyl vinyl ether is at least one selected from perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, or perfluoropropyl vinyl ether;

[0012] The mass ratio of the tetrafluoroethylene, perfluoroalkyl vinyl ether, and aromatic aldehyde-containing fluorinated vinyl ether is 1:1-2:0.01-0.1.

[0013] Preferably, the sulfidation point monomer is at least one selected from 1-bromo-2,2-difluoroethylene, trifluorobromoethylene, 4-bromo-3,3,4,4-tetrafluorobutene, 4-bromo-1,1,2-trifluoro1-butene, or brominated ethyl vinyl ether; the chain transfer agent is at least one selected from 1,2-diiodoperfluoroethane, 1,3-diiodoperfluoropropane, 1,4-diiodoperfluorobutane, 1,3-diiodo-2-chloroperfluoropropane, or iodomethane.

[0014] The mass ratio of the tetrafluoroethylene, the sulfurization point monomer, and the chain transfer agent is 1:0.02-0.1:0.01-0.05.

[0015] Preferably, the amino-graphene is obtained by condensing graphene oxide and diamine, followed by a reduction reaction;

[0016] The diamine is at least one of ethylenediamine or butanediamine, and the reducing agent for the reduction reaction is at least one of hydrazine hydrate or sodium borohydride.

[0017] Preferably, the carbon black is at least one of carbon black N550, carbon black N774, or carbon black N990; the crosslinking agent is at least one of dicumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, or bis-tert-butylperoxyisopropylbenzene; and the co-crosslinking agent is at least one of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane or 2,2-bis(4-hydroxyphenyl)hexafluoropropane.

[0018] In this invention, a synergistic crosslinking system of peroxide crosslinking agent and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane or 2,2-bis(4-hydroxyphenyl)hexafluoropropane is used. The peroxide crosslinking agent decomposes at high temperature to generate free radicals, which initiate crosslinking reactions between rubber molecular chains, forming carbon-carbon crosslinking bonds and improving the strength and modulus of the rubber. 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane or 2,2-bis(4-hydroxyphenyl)hexafluoropropane can react with the aromatic aldehyde active groups in the rubber molecular chains to form a crosslinked structure, further increasing the crosslinking density. The two crosslinking agents have different mechanisms of action, and their synergistic effect can form a more complex and stable crosslinked network structure, thereby further improving the overall performance of the sealing material.

[0019] Preferably, the processing aid includes at least one of an antioxidant, a heat stabilizer, a lubricant, or a dispersant.

[0020] The present invention also proposes a method for preparing the above-mentioned perfluoroether rubber sealing material, comprising the following steps:

[0021] S1. Add perfluoroether rubber raw rubber and amino graphene to a mixer and mix at 110-120℃ for 3-5 minutes. Then add carbon black and mix at 145-155℃ for 10-12 minutes to obtain a premixed rubber.

[0022] S2. Add the premixed rubber, crosslinking agent, co-crosslinking agent, and processing aid to a two-roll mill and continue mixing at 110-120°C for 4-6 minutes. Place the resulting mixed rubber into a mold, hot press it into shape, and then vulcanize it to obtain the perfluoroether rubber sealing material.

[0023] Preferably, the vulcanization includes: compression vulcanization at 160-180℃ and 10-30MPa for 15-25 min; and vulcanization at 280-290℃ for 12-18 h.

[0024] Compared with the prior art, the sealing material of perfluoroether rubber and its preparation method provided by the present invention add a small amount of amino graphene to the perfluoroether rubber raw rubber with a specific structure, and at the same time optimize the filler and vulcanization system. Under the condition of ensuring a high rubber content in the entire formulation system, the sealing material provided by the present invention has excellent hardness, tensile strength and resistance to compression deformation, and the material also has excellent resistance to media. Attached Figure Description

[0025] Figure 1 The infrared spectrum of the perfluoroether rubber raw material described in Example 1 of this invention;

[0026] Figure 2 This is a schematic diagram of the perfluoroether rubber sealing material described in Embodiment 1 of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will be described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0028] Example 1

[0029] A sealing material of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 10 parts of amino graphene, 25 parts of carbon black (carbon black N550), 2 parts of crosslinking agent (dicumyl peroxide), 1 part of co-crosslinking agent (2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane), and 0.5 parts of processing aid (sodium stearate);

[0030] The preparation method of the perfluoroether rubber raw rubber includes:

[0031] Water, dipotassium hydrogen phosphate, and sodium perfluorooctanoate were added to a reaction vessel at a mass ratio of 100:0.005:0.01 and stirred until homogeneous. After purging the air in the reaction vessel with nitrogen, aromatic aldehyde-containing fluorinated vinyl ether was added and stirred until homogeneous. The mixture was heated to 95°C, and a mixture of tetrafluoroethylene and perfluoropropyl vinyl ether was pressurized using a diaphragm compressor, raising the pressure inside the reaction vessel to 3 MPa. Then, under stirring conditions, potassium persulfate, the sulfidation point monomer 4-bromo-3,3,4,4-tetrafluorobutene, and the chain transfer agent 1,2-diiodoperfluoroethane were added. During the reaction... A mixture of tetrafluoroethylene and perfluoropropyl vinyl ether was continuously pressurized to maintain a constant pressure. The reaction was stirred until the predetermined feed amount was reached. The mass ratio of tetrafluoroethylene, perfluoropropyl vinyl ether, aromatic fluorinated vinyl ether, 4-bromo-3,3,4,4-tetrafluorobutene, 1,2-diiodoperfluoroethane, and potassium persulfate was 1:1.5:0.05:0.06:0.02:0.01. After cooling to room temperature, the polymerization reaction was terminated, and magnesium chloride aqueous solution was added for coagulation. The mixture was filtered, washed with water, and vacuum dried to obtain perfluoroether rubber raw rubber. Its infrared spectrum is shown below. Figure 1 As shown;

[0032] The aromatic aldehyde-containing fluorinated vinyl ether is prepared by the following method:

[0033] p-Hydroxybenzaldehyde was dissolved in N,N-dimethylformamide (DMF), and pyridine and 4-bromo-1,1,2-trifluoro-1-butene were added. The molar ratio of p-hydroxybenzaldehyde, pyridine, and 4-bromo-1,1,2-trifluoro-1-butene was 1:0.5:1. The mixture was heated to 80°C and stirred for 24 hours. After rotary evaporation and concentration, the mixture was washed with water, extracted with petroleum ether, dried, and rotary evaporated again to obtain the aromatic aldehyde-containing fluorinated vinyl ether, with the following structural formula:

[0034]

[0035] Its structural characterization data are as follows: 1 H NMR (400MHz, CDCl3) δ 9.81 (s, 1H), 7.82 (d, J=7.8Hz, 2H), 7.24 (d, J=8.1Hz, 2H), 4.55 (m, 2H), 4.32 (m, 2H);

[0036] The preparation method of the amino-graphene includes:

[0037] Graphene oxide (monolayer, sheet diameter <40 μm, thickness <1 nm) was ultrasonically dispersed in DMF until homogeneous. Ethylenediamine was then added and stirred until homogeneous, with a graphene oxide to ethylenediamine mass ratio of 1:0.1. The mixture was heated to 80 °C and stirred for 4 h. Hydrazine hydrate (N₂H₄·H₂O) was then added, with a graphene oxide to hydrazine hydrate mass ratio of 1:1. The mixture was heated to 90 °C and stirred for 4 h. The mixture was then filtered, washed with water, and dried to obtain aminographene, the structure of which is shown below.

[0038]

[0039] The preparation method of the above-mentioned perfluoroether rubber sealing material includes:

[0040] (1) Add perfluoroether rubber raw rubber and amino graphene to a mixer for mixing. Mix at 115°C for 4 min, then add carbon black and mix at 150°C for 10 min to obtain a premixed rubber.

[0041] (2) The premixed rubber, crosslinking agent, co-crosslinking agent, and processing aid are added to a two-roll mill and mixed for 5 minutes at 115°C. The resulting mixed rubber is placed in an O-ring mold for hot pressing and molding, followed by vulcanization treatment. The molding vulcanization is carried out at 170°C and 20MPa for 20 minutes, and then at 280°C for 12 hours. The mold is removed, and the mixture is allowed to cool naturally and demolded to obtain the perfluoroether rubber sealing material. Its product schematic diagram is shown below. Figure 2 As shown.

[0042] Example 2

[0043] A sealing material made of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 5 parts of amino graphene, 30 parts of carbon black (carbon black N774), 1 part of crosslinking agent (benzoyl peroxide), and 2 parts of co-crosslinking agent (2,2-bis(4-hydroxyphenyl)hexafluoropropane).

[0044] The preparation method of the perfluoroether rubber raw rubber includes:

[0045] Water, dipotassium hydrogen phosphate, and sodium perfluorooctanoate were added to a reaction vessel at a mass ratio of 100:0.005:0.01 and stirred until homogeneous. After purging the air in the reaction vessel with nitrogen, aromatic aldehyde-containing fluorinated vinyl ether was added and stirred until homogeneous. The mixture was heated to 85°C, and a mixture of tetrafluoroethylene and perfluoromethyl vinyl ether was pressurized using a diaphragm compressor, raising the pressure inside the reaction vessel to 3 MPa. Then, under stirring conditions, potassium persulfate, the sulfidation point monomer 1-bromo-2,2-difluoroethylene, and the chain transfer agent 1,3-diiodoperfluoropropane were added. During the reaction, tetrafluoroethylene and... A mixture of perfluoromethyl vinyl ethers was stirred at a constant pressure until a predetermined feed amount was reached. The mass ratio of tetrafluoroethylene, perfluoromethyl vinyl ether, aromatic aldehyde-containing fluorinated vinyl ether, 1-bromo-2,2-difluoroethylene, 1,3-diiodoperfluoropropane, and potassium persulfate was 1:1:0.05:0.06:0.02:0.01. After cooling to room temperature, the polymerization reaction was terminated, and magnesium chloride aqueous solution was added for coagulation. The mixture was filtered, washed with water, and vacuum dried to obtain perfluoroether rubber raw material. The aromatic aldehyde-containing fluorinated vinyl ether was prepared using the method described in Example 1.

[0046] The amino-graphene was also prepared using the method described in Example 1.

[0047] The preparation method of the above-mentioned perfluoroether rubber sealing material includes:

[0048] (1) Add perfluoroether rubber raw rubber and amino graphene to a mixer for mixing. Mix at 110°C for 5 min, then add carbon black and mix at 145°C for 12 min to obtain a premixed rubber.

[0049] (2) Add the premixed rubber, crosslinking agent, and co-crosslinking agent to the open mill and continue mixing at 120°C for 4 minutes. Place the resulting mixed rubber into the O-ring mold for hot pressing and then vulcanize it. Mold vulcanize at 160°C and 30MPa for 15 minutes and vulcanize at 290°C for 12 hours. Remove the mold, allow it to cool naturally and demold to obtain the perfluoroether rubber sealing material.

[0050] Example 3

[0051] A sealing material of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 15 parts of amino graphene, 20 parts of carbon black (carbon black N990), 3 parts of crosslinking agent (2,5-dimethyl-2,5-di(tert-butylperoxy)hexane), 0.5 parts of co-crosslinking agent (2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane), and 0.5 parts of processing aid (sodium stearate);

[0052] The perfluoroether rubber raw rubber was prepared using the method described in Example 1;

[0053] The preparation method of the amino-graphene includes:

[0054] Graphene oxide (monolayer, sheet diameter <40μm, thickness <1nm) was added to DMF and ultrasonically dispersed evenly. Butylene diamine was added and stirred evenly. The mass ratio of graphene oxide to butylene diamine was 1:0.2. The mixture was heated to 80℃ and stirred for 4 hours. Sodium borohydride (NaBH4) was then added. The mass ratio of graphene oxide to sodium borohydride was 1:1. The mixture was heated to 90℃ and stirred for 4 hours. The mixture was then filtered, washed with water, and dried to obtain aminographene.

[0055] The preparation method of the above-mentioned perfluoroether rubber sealing material includes:

[0056] (1) Add perfluoroether rubber raw rubber and amino graphene to a mixer and mix for 3 min at 120°C. Then add carbon black and mix for 10 min at 155°C to obtain a premixed rubber.

[0057] (2) Add the premixed rubber, crosslinking agent, co-crosslinking agent and processing aid to the open mill and continue to mix at 110°C for 6 minutes. Place the resulting mixed rubber into the O-ring mold for hot pressing and molding, and then vulcanize it. Mold vulcanize at 180°C and 10MPa for 25 minutes, and vulcanize at 280°C for 18 hours. Take out the mold, cool naturally and demold to obtain the perfluoroether rubber sealing material.

[0058] Example 4

[0059] A sealing material of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 10 parts of amino graphene, 25 parts of carbon black (carbon black N550), 2 parts of crosslinking agent (dicumyl peroxide), 1 part of co-crosslinking agent (tracelyl isocyanurate), and 0.5 parts of processing aid (sodium stearate).

[0060] The perfluoroether rubber raw material was prepared using the method described in Example 1; the amino graphene was also prepared using the method described in Example 1.

[0061] The preparation method of the above-mentioned perfluoroether rubber sealing material includes:

[0062] (1) Add perfluoroether rubber raw rubber and amino graphene to a mixer for mixing. Mix at 115°C for 4 min, then add carbon black and mix at 150°C for 10 min to obtain a premixed rubber.

[0063] (2) Add the premixed rubber, crosslinking agent, co-crosslinking agent and processing aid to the open mill and continue to mix at 115°C for 5 minutes. Place the resulting mixed rubber into the O-ring mold for hot pressing and molding, and then vulcanize it. Mold vulcanize at 170°C and 20MPa for 20 minutes, and vulcanize at 280°C for 12 hours. Take out the mold, cool naturally and demold to obtain the perfluoroether rubber sealing material.

[0064] Comparative Example 1

[0065] A sealing material of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 10 parts of amino graphene, 25 parts of carbon black (carbon black N550), 2 parts of crosslinking agent (dicumyl peroxide), 1 part of co-crosslinking agent (2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane), and 0.5 parts of processing aid (sodium stearate);

[0066] The preparation method of the perfluoroether rubber raw rubber includes:

[0067] Water, dipotassium hydrogen phosphate, and sodium perfluorooctanoate were added to a reaction vessel at a mass ratio of 100:0.005:0.01 and stirred until homogeneous. After purging the air from the reaction vessel with nitrogen, the temperature was raised to 95°C. A mixture of tetrafluoroethylene and perfluoropropyl vinyl ether was then pressurized using a diaphragm compressor, raising the pressure inside the reaction vessel to 3 MPa. Potassium persulfate, the sulfidation point monomer 4-bromo-3,3,4,4-tetrafluorobutene, and the chain transfer agent 1,2-diiodoperfluoroethane were then added under stirring. The reaction proceeded... During the process, a mixture of tetrafluoroethylene and perfluoropropyl vinyl ether was continuously injected to maintain a constant pressure. The reaction was stirred until the predetermined feed amount was reached. The mass ratio of tetrafluoroethylene, perfluoropropyl vinyl ether, 4-bromo-3,3,4,4-tetrafluorobutene, 1,2-diiodoperfluoroethane and potassium persulfate was 1:1.5:0.06:0.02:0.01. After cooling to room temperature, the polymerization reaction was terminated and magnesium chloride aqueous solution was added for coagulation. The mixture was filtered, washed with water, and vacuum dried to obtain perfluoroether rubber raw rubber.

[0068] The amino-graphene was prepared using the method described in Example 1.

[0069] The preparation method of the above-mentioned perfluoroether rubber sealing material includes:

[0070] (1) Add perfluoroether rubber raw rubber and amino graphene to a mixer for mixing. Mix at 115°C for 4 min, then add carbon black and mix at 150°C for 10 min to obtain a premixed rubber.

[0071] (2) Add the premixed rubber, crosslinking agent, co-crosslinking agent and processing aid to the open mill and continue to mix at 115°C for 5 minutes. Place the resulting mixed rubber into the O-ring mold for hot pressing and molding, and then vulcanize it. Mold vulcanize at 170°C and 20MPa for 20 minutes, and vulcanize at 280°C for 12 hours. Take out the mold, cool naturally and demold to obtain the perfluoroether rubber sealing material.

[0072] Comparative Example 2

[0073] A sealing material of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 10 parts of graphene oxide (graphene oxide, single layer, sheet diameter <40μm, thickness <1nm), 25 parts of carbon black (carbon black N550), 2 parts of crosslinking agent (dicumyl peroxide), 1 part of co-crosslinking agent (2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane), and 0.5 parts of processing aid (sodium stearate);

[0074] The perfluoroether rubber raw rubber was prepared using the method described in Example 1.

[0075] The preparation method of the above-mentioned perfluoroether rubber sealing material includes:

[0076] (1) Add perfluoroether rubber raw rubber and graphene oxide into a mixer and mix for 4 min at 115°C. Then add carbon black and mix for 10 min at 150°C to obtain a premixed rubber.

[0077] (2) Add the premixed rubber, crosslinking agent, co-crosslinking agent and processing aid to the open mill and continue to mix at 115°C for 5 minutes. Place the resulting mixed rubber into the O-ring mold for hot pressing and molding, and then vulcanize it. Mold vulcanize at 170°C and 20MPa for 20 minutes, and vulcanize at 280°C for 12 hours. Take out the mold, cool naturally and demold to obtain the perfluoroether rubber sealing material.

[0078] Comparative Example 3

[0079] A sealing material of perfluoroether rubber, the raw materials of which include, by weight: 100 parts of perfluoroether rubber raw rubber, 10 parts of amino graphene, 25 parts of carbon black (carbon black N550), 2 parts of crosslinking agent (dicumyl peroxide), 1 part of co-crosslinking agent (2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane), and 0.5 parts of processing aid (sodium stearate);

[0080] The perfluoroether rubber raw rubber was prepared using the method described in Example 1;

[0081] The preparation method of the amino-graphene includes:

[0082] Graphene oxide (monolayer, sheet diameter <40 μm, thickness <1 nm) was ultrasonically dispersed in anhydrous ethanol until homogeneous. Deionized water and γ-aminopropyltriethoxysilane were then added and stirred until homogeneous. The mass ratio of graphene oxide, deionized water, and γ-aminopropyltriethoxysilane was 1:2:0.5. The mixture was heated to 80 °C and stirred for 12 h. After filtration, washing with water, and drying, aminographene was obtained, with the structural schematic shown below.

[0083]

[0084] The preparation method of the above-mentioned perfluoroether rubber sealing material includes:

[0085] (1) Add perfluoroether rubber raw rubber and graphene oxide into a mixer and mix for 4 min at 115°C. Then add carbon black and mix for 10 min at 150°C to obtain a premixed rubber.

[0086] (2) Add the premixed rubber, crosslinking agent, co-crosslinking agent and processing aid to the open mill and continue to mix at 115°C for 5 minutes. Place the resulting mixed rubber into the O-ring mold for hot pressing and molding, and then vulcanize it. Mold vulcanize at 170°C and 20MPa for 20 minutes, and vulcanize at 280°C for 12 hours. Take out the mold, cool naturally and demold to obtain the perfluoroether rubber sealing material.

[0087] The perfluoroether rubber seals obtained from the above embodiments and comparative examples were prepared and tested according to standard test strips. The performance test data results are shown in Table 1 below.

[0088] Shore A hardness: Tested according to GB / T 531.1-2008 "Test method for indentation hardness of vulcanized rubber or thermoplastic rubber - Part 1: Shore hardness tester method (Shore hardness)";

[0089] Tensile strength and elongation at break: Tested in accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber";

[0090] Tear strength: Tested in accordance with GB / T 529-2008 "Determination of tear strength of vulcanized rubber or thermoplastic rubber";

[0091] Compression set: Tested according to GB / T1683-2018 "Determination of compression set of vulcanized rubber under constant deformation", test conditions: 290℃, 70h;

[0092] Heat resistance air aging: Tested according to GB / T3512-2014 "Hot air aging and heat resistance test of vulcanized rubber or thermoplastic rubber", test conditions: 300℃, 72h;

[0093] Plasma resistance: In an O2 plasma atmosphere, plasma treatment was performed for 60 min at a temperature of 150℃, a power of 500W, a vacuum of 1 Torr, and a gas flow rate of 500 sccm. The mass loss rate was then calculated.

[0094]

[0095] As shown in the table above, the sealing material of the present invention has good mechanical properties, high temperature resistance, and durability. However, in Comparative Example 1, the use of fluorinated vinyl ethers as comonomers in the perfluoroether rubber raw rubber is detrimental to the improvement of overall performance. In Comparative Example 2, the use of graphene oxide has low reactivity with the perfluoroether rubber raw rubber, which is also detrimental to the improvement of overall performance. Although amino graphene is also used in Comparative Example 3, the use of aminosilane coupling modification results in low reactivity of the grafted amino groups, which is also detrimental to the improvement of graphene dispersion performance. Therefore, the overall performance of the sealing material cannot be effectively improved.

[0096] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A sealing material of a perfluoroether rubber, characterized by, The raw materials include, by weight parts: perfluoroether rubber raw rubber 100 parts, amino graphene 5-15 parts, carbon black 20-30 parts, crosslinking agent 1-3 parts, co-crosslinking agent 0.5-2 parts, processing aid 0-3 parts; The perfluoroether rubber raw rubber is obtained by emulsion polymerization of tetrafluoroethylene, perfluoroalkyl vinyl ether and aryl aldehyde group fluorine-containing vinyl ether as comonomers under the conditions of a vulcanization point monomer and a chain transfer agent; The mass ratio of the tetrafluoroethylene, perfluoroalkyl vinyl ether and aryl aldehyde group fluorine-containing vinyl ether is 1:1-2:0.01-0.1; The aryl aldehyde group fluorine-containing vinyl ether has the following structure: The amino graphene is obtained by condensation reaction of graphene oxide and a binary amine, and then reduction reaction; the binary amine is at least one of ethylenediamine or butanediamine, and the reducing agent of the reduction reaction is at least one of hydrazine hydrate or sodium borohydride.

2. The seal material of claim 1, wherein The aryl aldehyde group fluorine-containing vinyl ether is obtained by electrophilic substitution reaction of p-hydroxybenzaldehyde and 4-bromo-1,1,2-trifluoro-1-butene.

3. The seal material of claim 1, wherein The perfluoroalkyl vinyl ether is at least one of perfluoromethyl vinyl ether, perfluoroethyl vinyl ether or perfluoropropyl vinyl ether.

4. The seal material of perfluoroelastomer according to any one of claims 1 to 3, characterized in that, The vulcanization point monomer is at least one of 1-bromo-2,2-difluoroethylene, trifluorobromoethylene, 4-bromo-3,3,4,4-tetrafluorobutene, 4-bromo-1,1,2-trifluoro-1-butene or brominated ethyl vinyl ether; and the chain transfer agent is at least one of 1,2-diiodoperfluoroethane, 1,3-diiodoperfluoropropane, 1,4-diiodoperfluorobutane, 1,3-diiodo-2-chloroperfluoropropane or iodomethane. The mass ratio of the tetrafluoroethylene, vulcanization point monomer and chain transfer agent is 1:0.02-0.1:0.01-0.

05.

5. The seal material of perfluoroether rubber according to any one of claims 1 to 3, characterized by, The carbon black is at least one of carbon black N550, carbon black N774 or carbon black N990; the crosslinking agent is at least one of dicumyl peroxide, dibenzoyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane or bis-tert-butylperoxyisopropylbenzene; and the co-crosslinking agent is at least one of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane or 2,2-bis(4-hydroxyphenyl)hexafluoropropane.

6. The seal material of perfluoroelastomer according to any one of claims 1 to 3, characterized in that, The processing aid includes at least one of an antioxidant, a heat stabilizer, a lubricant or a dispersant.

7. A process for the production of a sealing material of the perfluoroether rubber as claimed in any one of claims 1 to 6, characterized in that The method includes the following steps: S1, adding the perfluoroether rubber raw rubber and the amino graphene into a banbury mixer for mixing, mixing at 110-120℃ for 3-5min, then adding the carbon black, mixing at 145-155℃ for 10-12min to obtain a premixed rubber; S2, adding the premixed rubber, the crosslinking agent, the co-crosslinking agent and the processing aid into an open mill for mixing, mixing at 110-120℃ for 4-6min, then placing the obtained mixed rubber into a mold for hot pressing, and then vulcanizing to obtain the sealing material of the perfluoroether rubber.

8. The method for preparing the sealing material of perfluoroether rubber according to claim 7, characterized in that, The vulcanization includes: mold pressing at 160-180℃ and 10-30MPa for 15-25min, and vulcanizing at 280-290℃ for 12-18h.

Images