A static seal material and a preparation process thereof

Abstract

The application provides a kind of static seal material and its preparation process, belongs to sealing material technical field, including the following steps: pretreated carbon fiber is added to fluorine silane-rosin mixed solution, stirring, filtering, washing, vacuum drying, and fluorine silane / rosin-modified carbon fiber is prepared;Cerium dioxide nanoparticles are added to ultrapure water, ultrasonic treatment, dopamine hydrochloride and Tris are sequentially added, the pH value is adjusted to alkaline, high-speed stirring, filtering, washing, drying and preparing dopamine modified CeO2;Fluorine rubber is put into internal mixer, and the fluorine silane-rosin modified carbon fiber and vulcanization mixture are sequentially added to the internal mixer, mixed, mixed, thin layer processing, placed in mold, high temperature and high pressure vulcanization, heating, and vulcanization to prepare static seal material. The application can improve the tensile strength and durability of the static seal material while being suitable for low temperature working environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing materials, in particular to a static sealing material and a preparation process thereof. BACKGROUND

[0002] In the petroleum and chemical industry, the application of static sealing materials is very important, especially in the connection of oil and gas transportation pipelines. With the continuous development of oil and gas pipeline technology, the sealing performance of the pipeline has become one of the important factors to ensure the smooth transportation of oil and gas and the safety of the pipeline. Oil and gas pipelines not only need to withstand high pressure and high temperature, but also often face the challenges of corrosive media, chemicals and external environmental conditions. Therefore, choosing the right sealing material, especially the static sealing material that can maintain stable performance under extreme working conditions, is the basis for ensuring the long-term stable operation of the pipeline system.

[0003] During the service of static sealing materials, environmental conditions have a great influence on their performance. Factors such as temperature, chemical corrosion, and long-term light exposure can cause changes in the performance of sealing materials, thereby affecting the sealing effect. In the field of petroleum and chemical industry, the working environment of oil and gas transportation pipelines is more demanding, and the requirements for mechanical strength and chemical stability are higher; however, as the temperature rises, the performance of rubber or polymer materials often deteriorates significantly, especially under the combined action of high temperature and corrosive media, the sealing material may lose its original stability and chemical resistance, leading to sealing failure, and in severe cases, it may even cause safety hazards.

[0004] In such working environment, fluororubber, as a relatively good static sealing material, has become the first choice material in many applications due to its high chemical stability, high temperature resistance, oil resistance and corrosion resistance. Fluororubber can work at around 200℃, has significant chemical resistance and can resist the corrosion of most chemical media, and is particularly suitable for high temperature environments in the petroleum and chemical industry.

[0005] However, fluororubber, although excellent in many aspects, still has certain limitations. First, the tensile properties of fluororubber are relatively insufficient, which may lead to reduced sealing effect, leakage at the sealing site, and shortened service life. On the other hand, fluororubber will change its molecular structure when exposed to ozone or ultraviolet radiation for a long time, causing the material to harden, become brittle or degrade in performance, which usually occurs when fluororubber is exposed to outdoor environments or direct sunlight, resulting in a shorter service life.

[0006] Furthermore, fluororubber has relatively poor low-temperature resistance. While it typically maintains a certain degree of elasticity between -15°C and -20°C, it can experience severe shrinkage and hardening at lower temperatures, leading to a loss of elasticity and even brittle cracking. In low-temperature environments, particularly in oil and gas pipeline systems in cold regions, fluororubber, when used as a static sealing material, is prone to leaks, compromising sealing effectiveness.

[0007] Therefore, it is necessary to provide a static sealing material and a preparation process thereof to solve the problems existing in the above-mentioned prior art. Summary of the Invention

[0008] In view of this, the present invention provides a static sealing material and a preparation process thereof, which can improve tensile strength and durability while being suitable for low-temperature working environments.

[0009] To achieve the above object, the present invention provides a process for preparing a static sealing material, comprising the following steps:

[0010] S1. Adding the pretreated carbon fiber to a fluorine-containing silane-rosin mixture, stirring, filtering, washing, and vacuum drying to obtain a fluorine-containing silane / rosin-carbon fiber;

[0011] S2, adding cerium dioxide nanoparticles to water, ultrasonically treating it, adding dopamine hydrochloride and Tris in sequence, adjusting the pH value to alkaline, stirring at high speed, filtering, washing, and drying to obtain dopamine-modified CeO2;

[0012] S3. Put the fluororubber into an internal mixer for internal mixing, and add the silicone rubber composite material, dopamine-modified CeO2, aromatic oil, fluorinated silane / rosin-carbon fiber and vulcanized mixture in sequence, mix them, process them in a thin layer, place them in a mold, vulcanize them at high temperature and high pressure, increase the temperature, and vulcanize them to obtain a static sealing material.

[0013] The present invention prepares a fluorinated silane / rosin-carbon fiber filler as a rubber matrix, improving overall water and oil resistance and tensile properties. The fluorinated silane acts as a bridge between cellulose and rosin, increasing the efficiency of rosin grafting onto the carbon fiber surface. The fluorinated silane and rosin synergistically enhance the hydrophobicity and oleophobicity of the carbon fiber, further improving the interfacial interaction between the carbon fiber inorganic filler and the organic matrix. Furthermore, the silane molecules can self-polymerize to form a polysiloxane network that fills the micropores within the carbon fiber network, tightening the connection between the carbon fiber and the matrix and contributing to improved overall tensile strength.

[0014] The present invention prepares dopamine-modified CeO2 and adds it to a rubber matrix, enhancing both overall tensile strength and durability. Dopamine hydrochloride undergoes a self-polymerization reaction under alkaline conditions to produce polydopamine, which is then coated on the surface of ceria. The dopamine surface contains numerous phenolic hydroxyl groups, which can form hydrogen bonds with hydroxyl groups in the organic matrix, improving the compatibility and dispersibility of ceria within the rubber matrix. Furthermore, when exposed to ozone, CeO2 catalyzes the decomposition of ozone into more stable molecules (oxygen), reducing ozone damage to the rubber matrix. Furthermore, the uniformly dispersed ceria nanoparticles effectively inhibit molecular chain breakage in the rubber matrix caused by long-term UV irradiation, preventing crack propagation within the matrix and further improving overall tensile strength and durability.

[0015] The present invention uses fluororubber and silicone rubber composite materials in collaboration as the matrix material. The fluororubber gives the overall good oil resistance and water resistance. The addition of the silicone rubber composite material makes up for the defect of poor elasticity of fluororubber and gives the overall good low-temperature resistance. The two work together as the rubber matrix to improve the overall performance.

[0016] Optionally, the pretreated carbon fiber is obtained by washing the ground carbon fiber with ethyl acetate and acetone, and then drying at 100-120° C. for 40-60 minutes.

[0017] The present invention uses ethyl acetate and acetone to wash the carbon fiber to clean the surface thereof and remove pollutants and residues, thereby providing better surface properties for subsequent modification.

[0018] Optionally, the fluorinated silane-rosin mixed liquid is obtained by mixing a fluorinated silane coupling agent and an acetic acid solution with a volume concentration of 0.35% to 0.4%, hydrolyzing for 1 to 2 hours, and then adding a rosin emulsion with a mass concentration of 20% and magnetically stirring at 300 to 500 rpm for 10 to 20 minutes; the fluorinated silane coupling agent is one of 3-fluoropropyltrimethoxysilane, 2-(3,3,3-fluoropropyl)ethyltrimethoxysilane or fluorinated alkyltrimethoxysilane.

[0019] Optionally, in step S1, the stirring time is 6 to 8 hours at a speed of 150 rpm, the product is washed with deionized water 2 to 4 times after filtration, and the vacuum drying temperature is 100 to 120° C. for 40 to 60 minutes.

[0020] Optionally, in step S2, cerium dioxide nanoparticles are added to ultrapure water, ultrasonically treated for 2 to 3 hours, dopamine hydrochloride and Tris are added in sequence, the pH value is adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L, and then stirred at 2000 to 3000 rpm for 16 to 24 hours. After filtering, the mixture is washed with deionized water 2 to 4 times and dried at 60°C for 10 to 12 hours to obtain dopamine-modified CeO2.

[0021] In the preparation of dopamine-modified CeO2, high-speed stirring is performed for 16 to 24 hours to ensure that dopamine is fully wrapped on the surface of cerium dioxide particles to improve the effect of subsequent use as a filler.

[0022] Optionally, the silicone rubber composite material is obtained by uniformly mixing silicone rubber, perfluorodecanethiol grafted silicone rubber, fumed silica and hydroxy silicone oil at room temperature.

[0023] The present invention prepares a silicone rubber composite material, replacing the traditional method of directly using silicone rubber. The introduction of fluorinated side groups into the perfluorodecanethiol-grafted silicone rubber significantly increases the polarity of the silicone rubber, further enhancing the compatibility of the silicone rubber composite material with fluororubber. The enhanced bonding of the silicone / fluorine phases improves the blending effect, promoting the formation of a denser cross-linked network in the rubber, further enhancing the overall mechanical properties.

[0024] Optionally, the perfluorodecanethiol grafted silicone rubber is prepared by adding methyl vinyl silicone rubber to tetrahydrofuran, then adding perfluorodecanethiol, stirring for 30 to 50 minutes, adding 2,2-dimethoxy-2-phenylacetophenone, and placing the mixed solution in a sealed container, and irradiating it with a UV LED surface light source with a wavelength of 365 nm for 5 to 10 minutes;

[0025] The product is then flocculated with an ethanol solution, and the precipitate obtained after filtration is dissolved in tetrahydrofuran, and this step is repeated three times; and then dried in a vacuum oven at 55-65° C. for 16-24 hours.

[0026] The invention uses an ethanol solution to flocculate the product, and the precipitate obtained after filtering is dissolved in tetrahydrofuran, and the process is repeated three times to separate and purify the product, thereby improving the purity of the final product.

[0027] Optionally, in step S3, the fluororubber is placed in an internal mixer and mixed at 60°C and 25 r / min for 10 to 15 minutes. The silicone rubber composite material is first added and mixed for 5 minutes, and then dopamine-modified CeO2 and aromatic oil are added and mixed for 10 to 15 minutes. During this period, fluorinated silane / rosin-carbon fiber are added in 3 to 5 times, and finally the vulcanized mixture is added and mixed for 2 to 5 minutes. After thin layer processing on an open mill, it is placed in a mold, vulcanized at 160 to 170°C and 15 to 20 MPa for 10 to 20 minutes, and then heated to 180 to 200°C and vulcanized for 10 to 12 hours to finally obtain a static sealing material.

[0028] Optionally, the vulcanization mixture is obtained by mixing 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate; the mass ratio of the 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to triallyl isocyanurate is 2:3.

[0029] Optionally, the static sealing material comprises the following raw materials in parts by mass: 50-60 parts of fluororubber, 40-50 parts of silicone rubber composite material, 7-10 parts of dopamine-modified CeO2, 4-6 parts of aromatic oil, 20-35 parts of fluorinated silane / rosin-carbon fiber, and 4-6 parts of vulcanized mixture;

[0030] The silicone rubber composite material comprises the following raw materials in parts by mass: 40-50 parts of silicone rubber, 2-10 parts of perfluorodecanethiol grafted silicone rubber, 20 parts of fumed silica, and 2.5 parts of hydroxy silicone oil.

[0031] The present invention adopts the above mass proportion, which can better bring into play the comprehensive performance of the prepared static sealing material.

[0032] The above technical solution of the present invention includes at least the following beneficial effects:

[0033] 1. The present invention utilizes fluorinated silane / rosin-carbon fiber as a filler in a rubber matrix, improving water resistance, oil resistance, and tensile strength. The fluorinated silane promotes surface bonding between the rosin and carbon fibers, enhancing oleophobicity and hydrophobicity, and strengthening the interfacial interaction between the inorganic filler and the organic matrix. Simultaneously, the polysiloxane network formed by the self-polymerization of the silane improves the connection between the carbon fibers and the matrix, enhancing overall performance.

[0034] 2. This invention enhances overall tensile strength and durability by adding dopamine-modified CeO2 to the rubber matrix. The phenolic hydroxyl groups of dopamine form hydrogen bonds with the hydroxyl groups in the rubber matrix, improving compatibility and dispersibility. The evenly dispersed CeO2 nanoparticles effectively inhibit molecular chain breakage and crack propagation, enhancing overall performance.

[0035] 3. The present invention adopts a composite material of fluororubber and silicone rubber as a matrix. Fluororubber provides oil resistance and corrosion resistance, while silicone rubber improves the elasticity of fluororubber and enhances low-temperature resistance. The two work together to improve the overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The bar graph shows the mass change rate (%) of the samples of the embodiments of the present invention and the comparative examples after immersion in water or oil. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0038] Example 1

[0039] 100 parts of ground carbon fibers were washed with ethyl acetate and acetone, and then dried at 120°C for 40 min to obtain pretreated carbon fibers; 4 parts of 3-fluoropropyltrimethoxysilane were added to 500 parts of acetic acid solution with a volume concentration of 0.4%, hydrolyzed for 1.5 h, and then 60 parts of rosin emulsion with a mass concentration of 20% were added and magnetically stirred at 500 rpm for 15 min to obtain a fluorinated silane-rosin mixed solution; 50 parts of pretreated carbon fibers were added to the fluorinated silane-rosin mixed solution, stirred at 150 rpm at room temperature for 8 h, filtered, washed 4 times with deionized water, and vacuum dried at 100°C for 60 min to obtain a fluorinated silane / rosin-carbon fiber.

[0040] 15 parts of cerium dioxide nanoparticles were added to 1000 parts of ultrapure water and ultrasonically treated for 3 hours. 20 parts of dopamine hydrochloride and 16 parts of Tris (CAS No.: 77-86-1) were added in sequence. The pH value was adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L. The mixture was stirred at 3000 rpm for 24 hours. After filtering, it was washed with deionized water four times and dried at 60°C for 12 hours to obtain dopamine-modified CeO2.

[0041] 20 parts of methyl vinyl silicone rubber were added to 100 parts of tetrahydrofuran, followed by the addition of 1.5 parts of perfluorodecanethiol. After stirring for 50 minutes, 0.7 parts of 2,2-dimethoxy-2-phenylacetophenone were added, and the mixed solution was placed in a sealed container and irradiated with a UV LED surface light source with a wavelength of 365 nm for 10 minutes to initiate the reaction; the product was then flocculated with 300 parts of ethanol solution, and the precipitate obtained after filtration was dissolved in tetrahydrofuran. This step was repeated three times; and then dried in a vacuum oven at 55°C for 24 hours to obtain perfluorodecanethiol grafted silicone rubber.

[0042] The vulcanization mixture is prepared by mixing 4 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 6 parts of triallyl isocyanurate; 50 parts of silicone rubber are added to a double-roll mill, and then 10 parts of perfluorodecyl mercaptan grafted silicone rubber, 20 parts of fumed silica and 2.5 parts of hydroxy silicone oil are added, and then mixed uniformly at room temperature to obtain a silicone rubber composite material; 50 parts of fluororubber are placed in an internal mixer and kneaded at 60°C and 25 r / min for 15 min. n, first add 50 parts of silicone rubber composite material and mix for 5 minutes, then add 10 parts of dopamine-modified CeO2 and 6 parts of aromatic oil and mix for 15 minutes, during which time 35 parts of fluorinated silane / rosin-carbon fiber are added in 5 times until all are added, and finally 6 parts of vulcanized mixture are added and mixed for 5 minutes. After thin layer processing on an open mill, it is placed in a mold and vulcanized at 170°C and 15MPa for 15 minutes, then heated to 200°C and vulcanized for 10 hours to obtain a static sealing material.

[0043] Example 2

[0044] 100 parts of ground carbon fibers were washed with ethyl acetate and acetone, and then dried at 100°C for 40 minutes to obtain pretreated carbon fibers; 4 parts of 2-(3,3,3-fluoropropyl)ethyltrimethoxysilane were added to 500 parts of acetic acid solution with a volume concentration of 0.35%, hydrolyzed for 1 hour, and then 40 parts of rosin emulsion with a mass concentration of 20% were added and magnetically stirred at 300 rpm for 10 minutes to obtain a fluorinated silane-rosin mixed solution; 50 parts of pretreated carbon fibers were added to the fluorinated silane-rosin mixed solution, stirred at 150 rpm at room temperature for 6 hours, filtered, washed twice with deionized water, and vacuum dried at 100°C for 40 minutes to obtain a fluorinated silane / rosin-carbon fiber.

[0045] 10 parts of cerium dioxide nanoparticles were added to 1000 parts of ultrapure water and ultrasonically treated for 2 hours. 10 parts of dopamine hydrochloride and 13 parts of Tris (CAS No.: 77-86-1) were added in sequence. The pH value was adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L. The mixture was stirred at 2000 rpm for 16 hours. After filtering, it was washed with deionized water four times and dried at 60°C for 10 hours to obtain dopamine-modified CeO2.

[0046] 20 parts of methyl vinyl silicone rubber were added to 100 parts of tetrahydrofuran, followed by the addition of 1.5 parts of perfluorodecanethiol. After stirring for 30 minutes, 0.7 parts of 2,2-dimethoxy-2-phenylacetophenone was added, and the mixed solution was placed in a sealed container and irradiated with a UV LED surface light source with a wavelength of 365 nm for 5 minutes to initiate the reaction; the product was then flocculated with 300 parts of ethanol solution, and the precipitate obtained after filtration was dissolved in tetrahydrofuran. This step was repeated three times; and then dried in a vacuum oven at 55°C for 16 hours to obtain perfluorodecanethiol grafted silicone rubber.

[0047] The vulcanization mixture is prepared by mixing 4 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 6 parts of triallyl isocyanurate; 40 parts of silicone rubber are added to a double-roll mill, and then 2 parts of perfluorodecanethiol grafted silicone rubber, 20 parts of fumed silica and 2.5 parts of hydroxy silicone oil are added, and then mixed uniformly at room temperature to obtain a silicone rubber composite material; 60 parts of fluororubber are placed in an internal mixer and kneaded at 60°C and 25 r / min for 10 minutes. First, add 40 parts of silicone rubber composite material and mix for 5 minutes, then add 7 parts of dopamine-modified CeO2 and 4 parts of aromatic oil and mix for 10 minutes, during which time 20 parts of fluorinated silane / rosin-carbon fiber are added in 3 times until all are added, and finally 4 parts of vulcanized mixture are added and mixed for 2 minutes. After thin layer processing on an open mill, it is placed in a mold and vulcanized at 160°C and 15MPa for 10 minutes, then heated to 180°C and vulcanized for 10 hours to finally obtain a static sealing material.

[0048] Example 3

[0049] 100 parts of ground carbon fibers were washed with ethyl acetate and acetone, and then dried at 120°C for 60 min to obtain pretreated carbon fibers; 4 parts of 2-(3,3,3-fluoropropyl)ethyltrimethoxysilane were added to 500 parts of acetic acid solution with a volume concentration of 0.35%, hydrolyzed for 2 h, and then 60 parts of rosin emulsion with a mass concentration of 20% were added and magnetically stirred at 400 rpm for 20 min to obtain a fluorinated silane-rosin mixture; 50 parts of pretreated carbon fibers were added to the fluorinated silane-rosin mixture, stirred at 150 rpm at room temperature for 8 h, filtered, washed three times with deionized water, and vacuum dried at 120°C for 60 min to obtain a fluorinated silane / rosin-carbon fiber.

[0050] 15 parts of cerium dioxide nanoparticles were added to 1000 parts of ultrapure water and ultrasonically treated for 2.5 hours. 15 parts of dopamine hydrochloride and 16 parts of Tris (CAS No.: 77-86-1) were added in sequence. The pH value was adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L. The mixture was stirred at 2200 rpm for 18 hours. After filtering, it was washed with deionized water three times and dried at 60°C for 10 hours to obtain dopamine-modified CeO2.

[0051] 20 parts of methyl vinyl silicone rubber were added to 100 parts of tetrahydrofuran, followed by the addition of 1.5 parts of perfluorodecanethiol. After stirring for 50 minutes, 0.7 parts of 2,2-dimethoxy-2-phenylacetophenone was added, and the mixed solution was placed in a sealed container and irradiated with a UV LED surface light source with a wavelength of 365 nm for 8 minutes to initiate the reaction; the product was then flocculated with 300 parts of ethanol solution, and the precipitate obtained after filtration was dissolved in tetrahydrofuran, and this step was repeated 3 times; and then dried in a vacuum oven at 65°C for 24 hours to obtain perfluorodecanethiol grafted silicone rubber.

[0052] The vulcanization mixture is prepared by mixing 4 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 6 parts of triallyl isocyanurate; 45 parts of silicone rubber are added to a double-roll mill, and then 8 parts of perfluorodecyl mercaptan grafted silicone rubber, 20 parts of fumed silica and 2.5 parts of hydroxy silicone oil are added, and then mixed uniformly at room temperature to obtain a silicone rubber composite material; 55 parts of fluororubber are placed in an internal mixer and kneaded at 60°C and 25 r / min for 12 minutes. First, add 45 parts of silicone rubber composite material and mix for 5 minutes, then add 8 parts of dopamine-modified CeO2 and 5 parts of aromatic oil and mix for 12 minutes, during which time 30 parts of fluorinated silane / rosin-carbon fiber are added in 4 times until all are added, and finally 5 parts of vulcanized mixture are added and mixed for 4 minutes. After thin layer processing on an open mill, it is placed in a mold and vulcanized at 165°C and 20MPa for 20 minutes, then heated to 190°C and vulcanized for 11 hours to finally obtain a static sealing material.

[0053] Example 4

[0054] 100 parts of ground carbon fibers were washed with ethyl acetate and acetone, and then dried at 110°C for 50 min to obtain pretreated carbon fibers; 4 parts of fluorinated alkyltrimethoxysilane were added to 500 parts of acetic acid solution with a volume concentration of 0.4%, hydrolyzed for 2 h, and then 60 parts of rosin emulsion with a mass concentration of 20% were added and magnetically stirred at 300 rpm for 16 min to obtain a fluorinated silane-rosin mixed solution; 50 parts of pretreated carbon fibers were added to the fluorinated silane-rosin mixed solution, stirred at 150 rpm at room temperature for 7 h, filtered, washed twice with deionized water, and vacuum dried at 110°C for 45 min to obtain a fluorinated silane / rosin-carbon fiber.

[0055] 12 parts of cerium dioxide nanoparticles were added to 1000 parts of ultrapure water and ultrasonically treated for 2.5 hours. 20 parts of dopamine hydrochloride and 13 parts of Tris (CAS No.: 77-86-1) were added in sequence. The pH value was adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L. The mixture was stirred at 2000 rpm for 24 hours. After filtering, it was washed twice with deionized water and dried at 60°C for 12 hours to obtain dopamine-modified CeO2.

[0056] 20 parts of methyl vinyl silicone rubber were added to 100 parts of tetrahydrofuran, followed by the addition of 1.5 parts of perfluorodecanethiol. After stirring for 40 minutes, 0.7 parts of 2,2-dimethoxy-2-phenylacetophenone were added, and the mixed solution was placed in a sealed container and irradiated with a UV LED surface light source with a wavelength of 365 nm for 6 minutes to initiate the reaction; the product was then flocculated with 300 parts of ethanol solution, and the precipitate obtained after filtration was dissolved in tetrahydrofuran. This step was repeated three times; and then dried in a vacuum oven at 60°C for 20 hours to obtain perfluorodecanethiol grafted silicone rubber.

[0057] The vulcanization mixture is prepared by mixing 4 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 6 parts of triallyl isocyanurate; 42 parts of silicone rubber are added to a double-roll mill, and then 5 parts of perfluorodecanethiol grafted silicone rubber, 20 parts of fumed silica and 2.5 parts of hydroxy silicone oil are added and then mixed uniformly at room temperature to obtain a silicone rubber composite material; 52 parts of fluororubber are placed in an internal mixer and mixed at 60°C and 25 r / min for 13 minutes. First, add 48 parts of silicone rubber composite material and mix for 5 minutes, then add 8 parts of dopamine-modified CeO2 and 5 parts of aromatic oil and mix for 13 minutes, during which time 30 parts of fluorinated silane / rosin-carbon fiber are added in 4 times until all are added, and finally 4.5 parts of vulcanized mixture are added and mixed for 3 minutes. After thin layer processing on an open mill, it is placed in a mold and vulcanized at 170°C and 16MPa for 15 minutes, then heated to 200°C and vulcanized for 10 hours to finally obtain a static sealing material.

[0058] Example 5

[0059] 100 parts of ground carbon fibers were washed with ethyl acetate and acetone, and then dried at 120°C for 40 min to obtain pretreated carbon fibers; 4 parts of fluorinated alkyltrimethoxysilane were added to 500 parts of acetic acid solution with a volume concentration of 0.4%, hydrolyzed for 2 h, and then 55 parts of rosin emulsion with a mass concentration of 20% were added and magnetically stirred at 400 rpm for 12 min to obtain a fluorinated silane-rosin mixed solution; 50 parts of pretreated carbon fibers were added to the fluorinated silane-rosin mixed solution, stirred at 150 rpm at room temperature for 7.5 h, filtered, washed twice with deionized water, and vacuum dried at 100°C for 50 min to obtain a fluorinated silane / rosin-carbon fiber.

[0060] 12 parts of cerium dioxide nanoparticles were added to 1000 parts of ultrapure water and ultrasonically treated for 3 hours. 18 parts of dopamine hydrochloride and 14 parts of Tris (CAS No.: 77-86-1) were added in sequence. The pH value was adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L. The mixture was stirred at 2300 rpm for 22 hours. After filtering, it was washed twice with deionized water and dried at 60°C for 10 hours to obtain dopamine-modified CeO2.

[0061] 20 parts of methyl vinyl silicone rubber were added to 100 parts of tetrahydrofuran, followed by the addition of 1.5 parts of perfluorodecanethiol. After stirring for 50 minutes, 0.7 parts of 2,2-dimethoxy-2-phenylacetophenone was added, and the mixed solution was placed in a sealed container and irradiated with a UV LED surface light source with a wavelength of 365 nm for 8 minutes to initiate the reaction; the product was then flocculated with 300 parts of ethanol solution, and the precipitate obtained after filtration was dissolved in tetrahydrofuran. This step was repeated three times; and then dried in a vacuum oven at 55°C for 18 hours to obtain perfluorodecanethiol grafted silicone rubber.

[0062] The vulcanization mixture is prepared by mixing 4 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 6 parts of triallyl isocyanurate; 50 parts of silicone rubber are added to a double-roll mill, and then 2 parts of perfluorodecanethiol grafted silicone rubber, 20 parts of fumed silica and 2.5 parts of hydroxy silicone oil are added, and then mixed uniformly at room temperature to obtain a silicone rubber composite material; 57 parts of fluororubber are placed in an internal mixer and kneaded at 60°C and 25 r / min for 10 minutes. First, add 43 parts of silicone rubber composite material and mix for 5 minutes, then add 8 parts of dopamine-modified CeO2 and 5 parts of aromatic oil and mix for 10 minutes, during which time 25 parts of fluorinated silane / rosin-carbon fiber are added in 5 times until all are added, and finally 5 parts of vulcanized mixture are added and mixed for 4 minutes. After thin layer processing on an open mill, it is placed in a mold and vulcanized at 165°C and 17MPa for 12 minutes, then heated to 185°C and vulcanized for 12 hours to finally obtain a static sealing material.

[0063] Example 6

[0064] 100 parts of ground carbon fibers were washed with ethyl acetate and acetone, and then dried at 120°C for 40 min to obtain pretreated carbon fibers; 4 parts of 3-fluoropropyltrimethoxysilane were added to 500 parts of acetic acid solution with a volume concentration of 0.37%, hydrolyzed for 1.5 h, and then 45 parts of rosin emulsion with a mass concentration of 20% were added and magnetically stirred at 300 rpm for 16 min to obtain a fluorinated silane-rosin mixed solution; 50 parts of pretreated carbon fibers were added to the fluorinated silane-rosin mixed solution, stirred at 150 rpm at room temperature for 6.5 h, filtered, washed twice with deionized water, and vacuum dried at 110°C for 45 min to obtain a fluorinated silane / rosin-carbon fiber.

[0065] 12 parts of cerium dioxide nanoparticles were added to 1000 parts of ultrapure water and ultrasonically treated for 2.5 hours. 12 parts of dopamine hydrochloride and 15 parts of Tris (CAS No.: 77-86-1) were added in sequence. The pH value was adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L. The mixture was stirred at 2000 rpm for 18 hours. After filtering, it was washed with deionized water four times and dried at 60°C for 11 hours to obtain dopamine-modified CeO2.

[0066] 20 parts of methyl vinyl silicone rubber were added to 100 parts of tetrahydrofuran, and then 1.5 parts of perfluorodecanethiol were added. After stirring for 40 minutes, 0.7 parts of 2,2-dimethoxy-2-phenylacetophenone were added, and the mixed solution was placed in a sealed container and irradiated with a UV LED surface light source with a wavelength of 365nm for 7 minutes to initiate the reaction; then, 300 parts of ethanol solution were used to flocculate the product, and the precipitate obtained after filtration was dissolved in tetrahydrofuran, and this step was repeated 3 times; then, it was dried in a vacuum oven at 65°C for 24 hours to obtain perfluorodecanethiol grafted silicone rubber.

[0067] The vulcanization mixture is prepared by mixing 4 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 6 parts of triallyl isocyanurate; 47 parts of silicone rubber are added to a double-roll mill, and then 6 parts of perfluorodecyl mercaptan grafted silicone rubber, 20 parts of fumed silica and 2.5 parts of hydroxy silicone oil are added, and then mixed uniformly at room temperature to obtain a silicone rubber composite material; 58 parts of fluororubber are put into an internal mixer and kneaded at 60°C and 25r / min for 11 minutes, and then added first. 42 parts of silicone rubber composite material were added and mixed for 5 minutes, and then 9 parts of dopamine-modified CeO2 and 4.5 parts of aromatic oil were added and mixed for 12 minutes. During this period, 28 parts of fluorinated silane-rosin modified carbon fiber were added in 4 times until all were added. Finally, 4.5 parts of vulcanized mixture were added and mixed for 3 minutes. After thin layer processing on an open mill, it was placed in a mold and vulcanized at 160°C and 20MPa for 20 minutes. Then the temperature was raised to 200°C and vulcanized for 10 hours to finally obtain a static sealing material.

[0068] The present invention also carried out comparative examples and related tests.

[0069] Comparative Example 1

[0070] Compared with Example 1, the only difference is that fluorinated silane / rosin-carbon fiber is not prepared, and carbon fiber is directly added to the internal mixer instead of fluorinated silane / rosin-carbon fiber. The other preparation methods and components are exactly the same, and a static sealing material is finally obtained.

[0071] Comparative Example 2

[0072] Compared with Example 1, the only difference is that dopamine-modified CeO2 is not added during the preparation of the static sealing material. Other preparation methods and components are completely consistent, and the static sealing material is finally prepared.

[0073] Comparative Example 3

[0074] Compared with Example 1, the only difference is that no silicone rubber composite material is added in the process of preparing the static sealing material, and only fluororubber is used as the matrix. The other preparation methods are exactly the same as the components, namely: 100 parts of fluororubber are placed in an internal mixer, and mixed at 60°C and 25r / min for 15 minutes, 10 parts of dopamine-modified CeO2 and 6 parts of aromatic oil are added and mixed for 15 minutes, during which 35 parts of fluorinated silane / rosin-carbon fiber are added in 5 times until all are added, and finally 6 parts of the vulcanization mixture are added and mixed for 5 minutes. After thin layer processing on an open mill, it is placed in a mold, vulcanized at 170°C and 15MPa for 15 minutes, and then heated to 200°C and vulcanized for 10 hours to obtain a static sealing material.

[0075] Performance testing

[0076] Basic performance tests were performed on the static sealing material samples prepared in Examples 1 to 6 and Comparative Examples 1 to 3. The test methods are as follows:

[0077] Tensile strength and elongation at break: tested in accordance with the national testing standard GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber";

[0078] Low temperature resistance: According to the national standard test method GB / T1682-2014 "Determination of low temperature brittleness of vulcanized rubber - Single specimen method", the brittle temperature of the sample is tested as the low temperature resistance evaluation standard;

[0079] Rebound rate: tested in accordance with the national testing standard GB / T1681-2009 "Determination of rebound elasticity of vulcanized rubber";

[0080] Compression set: Tested in accordance with the national standard test method GB / T1683-2018 "Determination of permanent compression of vulcanized rubber at constant deformation", the test conditions are 200℃, 20h, and the compression rate is 30%;

[0081] The basic performance test results of the static sealing material samples prepared in Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 1.

[0082] Table 1: Basic performance test table

[0083]

[0084] As can be seen from Table 1, the mechanical properties and low temperature resistance of the static sealing material samples prepared using Examples 1 to 6 of the present invention are better than those of Comparative Examples 1 to 3.

[0085] According to the data analysis in Table 1, in Comparative Example 1, since the carbon fiber was not modified, the bonding between the fiber and the matrix was weak, the tensile strength, elongation at break, and rebound rate were significantly reduced, and the compression permanent deformation performance was also significantly increased. In Comparative Example 3, since no silicone rubber composite material was added, the low temperature resistance and rebound rate were significantly reduced.

[0086] The durability of the static sealing material samples prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was evaluated using ozone resistance, artificial weathering resistance, and hot air aging resistance. The specific test methods are as follows:

[0087] Ozone resistance: tested in accordance with the national test standard GB / T24134-2009 "Evaluation of ozone resistance of rubber and plastic hoses under static conditions". The test conditions are: at an ozone concentration of (100±10)×10 -8 In an environment of 40℃ for 48h, keep the elongation of the specimen at 20%±2% and observe whether cracks appear;

[0088] Artificial weathering resistance: tested in accordance with the national standard test method GB / T16585-1996 "Test method for artificial weathering of vulcanized rubber (fluorescent ultraviolet lamp)", and evaluated by the retention rate (%) of tensile strength under alternating conditions of ultraviolet light and condensation;

[0089] The durability test results of the static sealing material samples prepared in Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 2.

[0090] Table 2: Durability test table

[0091]

[0092] As shown in Table 2, the durability of the static sealing material samples prepared using Examples 1 to 6 of the present invention is better than that of Comparative Examples 1 to 3. Among them, the durability of Comparative Example 2 is most significantly reduced due to the lack of dopamine-modified CeO2.

[0093] The present invention also conducts oil resistance and water resistance tests on the static sealing material samples prepared in Examples 1 to 6 and Comparative Examples 1 to 3 according to the national standard test method of GB-T1690-2010 "Test method for liquid resistance of vulcanized rubber or thermoplastic rubber", and evaluates the mass change rate (%) before and after the 72h immersion test. The test results of the mass change rate (%) of the samples after immersion in water or oil are shown in Figure 1 ,according to Figure 1 It can be clearly seen that in Comparative Example 1, since the carbon fiber is not modified, the mass change rate increases significantly, and water or oil can more easily penetrate into the sample, that is, the oil and water resistance decreases significantly.

[0094] In summary, the durability and mechanical strength of the static sealing material prepared by the present invention are significantly improved, and the low temperature resistance and medium intrusion resistance are also significantly improved, and it can be better applied in various working environments.

[0095] The above is a preferred embodiment of the present invention. Those skilled in the art may make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A preparation process of a static sealing material, characterized in that: The steps include: S1. Adding the pretreated carbon fiber to a fluorine-containing silane-rosin mixture, stirring, filtering, washing, and vacuum drying to obtain a fluorine-containing silane / rosin-carbon fiber; S2, adding cerium dioxide nanoparticles to water, ultrasonically treating it, adding dopamine hydrochloride and Tris in sequence, adjusting the pH value to alkaline, stirring at high speed, filtering, washing, and drying to obtain dopamine-modified CeO2; S3, putting fluororubber into an internal mixer for internal mixing, adding silicone rubber composite material, dopamine-modified CeO2, aromatic oil, fluorinated silane / rosin-carbon fiber and vulcanized mixture in sequence, mixing, processing thin layers, placing in a mold, vulcanizing at high temperature and high pressure, heating, and vulcanizing to obtain a static sealing material; The pretreated carbon fiber is obtained by washing the ground carbon fiber with ethyl acetate and acetone, and then drying at 100-120° C. for 40-60 minutes; The silicone rubber composite material is obtained by uniformly mixing silicone rubber, perfluorodecanethiol grafted silicone rubber, fumed silica and hydroxy silicone oil at room temperature; The sulfurization mixture is obtained by mixing 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate.

2. The process for preparing a static sealing material according to claim 1, characterized in that: The fluorinated silane-rosin mixed liquid is prepared by mixing a fluorinated silane coupling agent and an acetic acid solution having a volume concentration of 0.35% to 0.4%, hydrolyzing the mixture for 1 to 2 hours, and then adding a rosin emulsion having a mass concentration of 20% and magnetically stirring the mixture at 300 to 500 rpm for 10 to 20 minutes. The fluorinated silane coupling agent is selected from the group consisting of 3-fluoropropyltrimethoxysilane, 2-(3,3,3-fluoropropyl)ethyltrimethoxysilane, and fluorinated alkyltrimethoxysilane.

3. The process for preparing a static sealing material according to claim 1, characterized in that: In step S1, the stirring time is 6-8 hours at a speed of 150 rpm, and after filtration, the mixture is washed with deionized water 2-4 times. The vacuum drying temperature is 100-120° C. and the time is 40-60 minutes.

4. The process for preparing a static sealing material according to claim 1, wherein: In step S2, cerium dioxide nanoparticles are added to ultrapure water and ultrasonically treated for 2 to 3 hours. Dopamine hydrochloride and Tris are added in sequence. The pH value is adjusted to 8.5 using a hydrochloric acid solution with a molar concentration of 0.1 mol / L. The mixture is stirred at 2000 to 3000 rpm for 16 to 24 hours. After filtering, the mixture is washed with deionized water 2 to 4 times and dried at 60°C for 10 to 12 hours to obtain dopamine-modified CeO2.

5. The process for preparing a static sealing material according to claim 1, wherein: The perfluorodecanethiol grafted silicone rubber is prepared by adding methyl vinyl silicone rubber to tetrahydrofuran, then adding perfluorodecanethiol, stirring for 30-50 minutes, adding 2,2-dimethoxy-2-phenylacetophenone, and placing the mixed solution in a sealed container. The mixture is irradiated with a 365nm ultraviolet LED surface light source for 5-10 minutes. The product is then flocculated with an ethanol solution, and the precipitate obtained after filtration is dissolved in tetrahydrofuran. This step is repeated three times. The product is then dried in a vacuum oven at 55-65°C for 16-24 hours.

6. The process for preparing a static sealing material according to claim 1, wherein: In the step S3, the fluororubber is placed in an internal mixer and kneaded at 60° C. and a speed of 25 r / min for 10 to 15 minutes. The silicone rubber composite material is first added and mixed for 5 minutes. Then, the dopamine-modified CeO2 and the aromatic oil are added and mixed for 10 to 15 minutes. During this period, the fluorinated silane / rosin-carbon fiber are added in 3 to 5 times. Finally, the vulcanized mixture is added and mixed for 2 to 5 minutes. After thin layer processing on an open mill, it is placed in a mold and vulcanized at 160 to 170° C. and 15 to 20 MPa for 10 to 20 minutes. Then, the temperature is raised to 180 to 200° C. and vulcanized for 10 to 12 hours to finally obtain a static sealing material.

7. The process for preparing a static sealing material according to claim 1, wherein: The mass ratio of the 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to triallyl isocyanurate is 2:

3.

8. A static sealing material, characterized in that: Prepared according to the preparation process of a static sealing material according to any one of claims 1 to 7, comprising the following raw materials in parts by mass: 50-60 parts of fluororubber, 40-50 parts of silicone rubber composite material, 7-10 parts of dopamine-modified CeO2, 4-6 parts of aromatic oil, 20-35 parts of fluorinated silane / rosin-carbon fiber, and 4-6 parts of a vulcanized mixture; the silicone rubber composite material comprises the following raw materials in parts by mass: 40-50 parts of silicone rubber, 2-10 parts of perfluorodecanethiol grafted silicone rubber, 20 parts of fumed silica, and 2.5 parts of hydroxy silicone oil.

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