A rubber composite, a method for preparing the same and applications thereof

Abstract

This invention discloses a rubber composite material, its preparation method, and its application, belonging to the field of rubber composite materials for CCUS (carbon capture, utilization, and storage). The technical solution includes rubber, carbon black, a crosslinking agent, a co-crosslinking agent, and modified organomontmorillonite; after mixing and vulcanizing the rubber, carbon black, crosslinking agent, and co-crosslinking agent, the crosslinking density of the resulting material is 7.3 × 10⁻⁶. ‑4 -7.8×10 ‑4 mol·cm ‑3 The interlayer spacing of the modified organomontmorillonite is 1.26-3.46 nm. This invention is applied to CCUS (carbon capture, utilization, and storage) seals, solving the problem of poor resistance to supercritical CO2 corrosion of existing rubber sealing materials under actual working conditions. This rubber composite material exhibits excellent corrosion resistance in a supercritical CO2 environment at a temperature of 130℃ and a pressure of 9MPa.

Description

Technical Field

[0001] This invention belongs to the field of rubber composite materials for CCUS (carbon capture, utilization and storage), and particularly relates to a rubber composite material, its preparation method and application. Background Technology

[0002] Carbon capture, utilization and storage (CCUS) is a key technology for reducing carbon emissions and improving oil recovery in current oil extraction. The effectiveness of this engineering technology and the maturity of the process depend on the manufacturing technology of the seals, which include elastomeric sealing materials, gaskets, linings and coatings, and are required to exhibit the ability to resist corrosion under harsh operating conditions.

[0003] Under high pressure and high temperature conditions, carbon dioxide often exists in the form of supercritical fluid (SC-CO2), exhibiting strong corrosiveness to rubber sealing materials. As the most critical sealing component in oil production operations, packers and their associated rubber sealing materials are extremely susceptible to severe corrosion in supercritical CO2 media. This leads to a rapid decline in the overall mechanical properties of the materials, resulting in a sharp decrease in the sealing capacity and effectiveness of the seals, and ultimately causing system failures.

[0004] Fluororubber (FKM) is a polymer renowned for its excellent chemical resistance, high-temperature resistance, and oil resistance, making it widely used in demanding fields such as aerospace, petrochemicals, and energy equipment. With the increasing application of carbon dioxide miscible flooding technology in enhanced oil recovery, supercritical CO2 media, as a particularly harsh operating environment, are finding wider use, and the applicability of FKM composite materials in supercritical carbon dioxide (SC-CO2) environments is also expanding.

[0005] However, supercritical CO2 media often cause significant degradation of FKM materials, such as expansion and corrosion, thereby damaging the integrity of the materials and threatening the safe operation of oil wells. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is that the existing rubber sealing materials have poor resistance to supercritical CO2 corrosion under actual working conditions. The present invention proposes a rubber composite material that exhibits excellent corrosion resistance in a supercritical CO2 environment at a temperature of 130℃ and a pressure of 9MPa, its preparation method and application.

[0007] To solve the aforementioned technical problem, the technical solution adopted by the present invention is as follows: This invention provides a rubber composite material comprising rubber, carbon black, a crosslinking agent, a co-crosslinking agent, and modified organomontmorillonite; the crosslinking density of the material obtained after mixing and vulcanizing the rubber, carbon black, crosslinking agent, and co-crosslinking agent is 7.3 × 10⁻⁶. -4 -7.8×10-4 mol·cm -3 The interlayer spacing of the modified organomontmorillonite is 1.26-3.46 nm.

[0008] In some embodiments, the rubber composite material comprises, by weight: 100 parts rubber, 15-30 parts carbon black, 2.5-4.5 parts crosslinking agent, 8-12 parts co-crosslinking agent, and 0.25-3 parts modified organomontmorillonite.

[0009] In some embodiments, the rubber is selected from at least one of fluororubber, hydrogenated nitrile rubber, and fluoroether rubber; the fluororubber is selected from one of BR9151, FKM200S, FKM600S, FKM-246, or FEPM.

[0010] In some embodiments, the carbon black is selected from at least one of spray-dried carbon black, super abrasion-resistant carbon black 220, semi-reinforcing carbon black N330, N550, N774, and N990.

[0011] In some embodiments, the crosslinking agent is 2,5-dimethyl-2,5-di-tert-butylperoxyhexane or cumene peroxide, and the co-crosslinking agent is triallyl isocyanurate.

[0012] In some embodiments, the modified organomontmorillonite is selected from one of SMP, SMF-LV, SMDK10, and SMDK18.

[0013] In some embodiments, the crosslinking density of the rubber composite material is 8.59 × 10⁻⁶. -4 -9.68×10 -4 mol·cm -3 .

[0014] Another aspect of the present invention provides a method for preparing a rubber composite material according to any of the above technical solutions, comprising: plasticizing rubber by open milling, sequentially adding modified organomontmorillonite and carbon black, and mixing; then adding crosslinking agent and co-crosslinking agent in batches, mixing, and sheeting to obtain a compound rubber, and cooling; and subjecting the cooled compound rubber to a first-stage vulcanization and a second-stage vulcanization to obtain a rubber composite material.

[0015] The present invention also provides the application of the rubber composite material of any of the above technical solutions as a sealing element in a supercritical CO2 environment with a temperature of 130°C and a pressure of 9MPa.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a rubber composite material in which, based on moderate cross-linking, a large interlayer spacing modified organomontmorillonite (OMMT) is introduced into the constructed chemical network structure. Utilizing the excellent dispersibility and barrier properties of the large interlayer spacing OMMT, the prepared rubber composite material exhibits superior resistance to supercritical CO2 corrosion. This rubber composite material demonstrates excellent resistance to supercritical carbon dioxide corrosion in a supercritical CO2 environment at a temperature of 130°C and a pressure of 9 MPa. Detailed Implementation

[0017] The technical solutions in specific embodiments of the present invention will be described in detail and completely below. Obviously, the described embodiments are only some specific implementations of the overall technical solution of the present invention, and not all implementations. Based on the overall concept of the present invention, all other embodiments obtained by those skilled in the art fall within the protection scope of the present invention.

[0018] This invention provides a rubber composite material comprising rubber, carbon black, a crosslinking agent, a co-crosslinking agent, and modified organomontmorillonite; the crosslinking density of the material obtained after mixing and vulcanizing the rubber, carbon black, crosslinking agent, and co-crosslinking agent is 7.3 × 10⁻⁶. -4 -7.8×10 -4 mol·cm -3 The interlayer spacing of the modified organomontmorillonite is 1.26-3.46 nm.

[0019] Since the cross-linked network structure of rubber inhibits the penetration and swelling of carbon dioxide into the rubber matrix and affects the diffusion kinetics in supercritical CO2 media, constructing a cross-linked network in the fluororubber matrix helps to improve the mechanical properties and thermal stability of FKM in supercritical CO2 media.

[0020] Besides chemical cross-linking networks that can inhibit supercritical CO2 diffusion, layered silicates, such as organo-montmorillonite (OMMT), also possess the ability to block the rapid diffusion and penetration of supercritical CO2 into rubber matrices. In particular, using cationic surfactants with longer molecular chains through cation exchange processes can produce organo-montmorillonite with even larger interlayer spacing. This organo-montmorillonite with larger interlayer spacing exhibits better dispersion and composite effects, demonstrating superior composite performance as a modifier for improving the mechanical properties of elastomeric sealing materials and enhancing their resistance to CO2 corrosion.

[0021] The rubber composite material of the present invention includes a crosslinking agent and modified organic montmorillonite. It adopts a coupling technology of chemical crosslinking and inorganic sheet particle physical crosslinking to regulate the slow diffusion penetration and escape rate of supercritical CO2 fluid in the rubber matrix, which can effectively improve the rubber's resistance to supercritical CO2 fluid corrosion.

[0022] Furthermore, this invention has found that moderate crosslinking helps improve the corrosion resistance of materials, rather than simply increasing the crosslinking density. Increasing the crosslinking density is not positively correlated with the rubber's resistance to supercritical CO2 fluid corrosion. Appropriate crosslinking density can effectively suppress expansion caused by supercritical CO2, while excessive crosslinking may lead to embrittlement and accelerate stress cracking. Based on moderate crosslinking, the above technical solution introduces large-interlayer-spacing OMMT into the constructed chemical network structure. Due to the excellent dispersibility and barrier properties of large-interlayer-spacing OMMT, the prepared novel fluororubber composite material exhibits superior resistance to supercritical CO2 corrosion.

[0023] It is particularly important to emphasize that the appropriate crosslinking density here does not simply refer to the crosslinking density of the aforementioned rubber composite material. More crucial in this invention is the control of the crosslinking density of the rubber, carbon black, crosslinking agent, co-crosslinking agent, and modified organomontmorillonite. The crosslinking density of the material obtained after mixing and vulcanizing the rubber, carbon black, crosslinking agent, and co-crosslinking agent must meet a certain range. Only by introducing modified organomontmorillonite on the basis of a material system that meets this crosslinking density range can the rubber composite material be guaranteed to exhibit excellent resistance to supercritical carbon dioxide corrosion in a supercritical CO2 environment at a temperature of 130°C and a pressure of 9 MPa.

[0024] It is understandable that the crosslinking density of the material obtained after mixing and vulcanizing rubber, carbon black, crosslinking agent, and co-crosslinking agent can still be 7.31 × 10⁻⁶. -4 mol•cm -3 7.35×10 -4 mol•cm -3 7.40×10 -4 mol•cm -3 7.45×10 -4 mol•cm -3 7.50×10 -4 mol•cm -3 7.55×10 -4 mol•cm -3 7.60×10 -4 mol•cm -3 7.65×10 -4 mol•cm -3 7.70×10 -4 mol•cm -3 7.75×10 -4 mol•cm -3The interlayer spacing of modified organomontmorillonite can also be any value within the range of 1.26nm, 1.27nm, 1.30nm, 1.40nm, 1.50nm, 1.60nm, 1.70nm, 1.80nm, 1.90nm, 2.01nm, 2.20nm, 2.40nm, 2.60nm, 2.80nm, 3.00nm, 3.20nm, 3.40nm, 3.45nm, and 1.26nm.

[0025] In some embodiments, the rubber composite material comprises, by weight: 100 parts rubber, 15-30 parts carbon black, 2.5-4.5 parts crosslinking agent, 8-12 parts co-crosslinking agent, and 0.25-3 parts modified organomontmorillonite.

[0026] Understandably, the amount of carbon black can be any value within the range of 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, etc.; the amount of crosslinking agent can be any value within the range of 3.0 parts, 3.5 parts, 4.0 parts, etc.; the amount of co-crosslinking agent can be any value within the range of 9 parts, 10 parts, 11 parts, etc.; and the amount of modified organomontmorillonite can be any value within the range of 0.30 parts, 0.35 parts, 0.40 parts, 0.45 parts, 0.50 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, etc.

[0027] In some embodiments, the rubber is selected from at least one of fluororubber, hydrogenated nitrile rubber, and fluoroether rubber; the fluororubber is selected from one of BR9151, FKM200S, FKM600S, FKM-246, or FEPM. In some embodiments, the rubber is FKM600S.

[0028] The aforementioned technical solution prioritizes the use of fluororubber (FKM) as the rubber matrix, triallyl isocyanurate (TAIC) as a co-crosslinking agent, and organomontmorillonite (OMMT) as a physical barrier agent. A novel FKM composite material is prepared through a shear-mix vulcanization process. Based on the synergistic effect of the chemical crosslinking of TAIC and the physical crosslinking of organomontmorillonite, the prepared FKM composite material exhibits high resistance to supercritical CO2 corrosion, providing a practical and feasible processing technology for preparing high-performance corrosion-resistant rubber sealing materials suitable for carbon capture, utilization, and storage (CCUS) applications.

[0029] In some embodiments, the carbon black is selected from at least one of spray-dried carbon black, super abrasion-resistant carbon black 220, and semi-reinforcing carbon blacks N330, N550, N774, and N990. Spray-dried carbon black is preferred in this invention. Due to the chemical inertness of its main chain, FKM has limited interaction with carbon black, while spray-dried carbon black has lower reactivity, which can better balance the reinforcement and processing.

[0030] In some embodiments, the crosslinking agent is 2,5-dimethyl-2,5-di-tert-butylperoxide (DBPH) or cumene peroxide (DCP), and the co-crosslinking agent is triallyl isocyanurate (TAIC). Preferably, a peroxide vulcanization system constructed from 2,5-dimethyl-2,5-di-tert-butylperoxide (DBPH) and triallyl isocyanurate (TAIC) is used. This system is chosen primarily because it requires superior chemical stability in supercritical CO2 media. TAIC contains three highly reactive allyl double bonds, which can synergistically interact with the free radicals generated by the decomposition of the peroxide (DBPH), significantly improving crosslinking efficiency and constructing a more complete network structure.

[0031] In some embodiments, the modified organomontmorillonite is selected from one of SMP, SMF-LV, SMDK10, and SMDK18.

[0032] Modified organomontmorillonite was prepared by the following steps: 6 g of Na-MMT and 200 g of deionized water were placed in a 500 mL three-necked flask at 80 °C and stirred vigorously for two hours. Subsequently, the mixture was cooled to a modification temperature of 60 °C, and a measured amount of cationic waterborne polyurethane resin intercalating agent was added. The mixture was then ultrasonically treated for 4 hours under high-speed mechanical stirring. After modification, the mixture was vacuum filtered and washed repeatedly 4-5 times. The washed solid was dried in a vacuum oven at 80 °C. The larger particles after drying were pulverized using a grinder and then ground in a mortar. Finally, the material was sieved through a 400-mesh molecular sieve for subsequent use, thus obtaining quaternary ammonium salt modified organomontmorillonite (OMMT) particles.

[0033] In some embodiments, the crosslinking density of the material obtained after mixing and vulcanizing rubber, carbon black, crosslinking agent, and co-crosslinking agent is calculated by the following method:

[0034] in, Ve The crosslinking density of the sample; V 0 represents the volume fraction of rubber at swelling equilibrium; m 0 represents the sample mass before swelling; m 1 and m 2 represents the sample mass before and after drying; f This represents the mass fraction of rubber in the vulcanized rubber. αThis refers to the rate of change in the sample's own mass. r r The density of rubber is taken as 1.85 g / cm³. 3 ; r s The solvent density is taken as 0.902 g / cm³. 3 ; x The Huggins parameters for rubber and ethyl acetate are given. Vs. The value is the molar volume of ethyl acetate solvent, which is 98.4 mL / mol.

[0035] In some embodiments, the crosslinking density of the rubber composite material is 8.59 × 10⁻⁶. -4 -9.68×10 -4 mol•cm -3 Understandably, the crosslinking density of the rubber composite material could also be 8.68 × 10⁻⁶. -4 mol•cm -3 8.96×10 -4 mol•cm -3 9.20×10 -4 mol•cm -3 9.40×10 -4 mol•cm -3 The values ​​at any point within its range. The mechanical properties exhibited by this rubber composite material after 10 days of corrosion in a supercritical CO2 environment at 130℃ and 9MPa pressure are significantly better than those of the original composite material.

[0036] Another aspect of the present invention provides a method for preparing a rubber composite material according to any of the above technical solutions, comprising: plasticizing rubber by open milling, sequentially adding modified organomontmorillonite and carbon black, and mixing; then adding crosslinking agent and co-crosslinking agent in batches, mixing, and sheeting to obtain a compound rubber, and cooling; and subjecting the cooled compound rubber to a first-stage vulcanization and a second-stage vulcanization to obtain a rubber composite material.

[0037] When the rubber is fluororubber, the preparation method of the above-mentioned rubber composite material adopts conventional methods to mix the above components, followed by vulcanization treatment to obtain the desired vulcanized rubber strip. A first-stage vulcanization is performed at 170℃ / 15MPa for 7 minutes, followed by a second-stage vulcanization at 200℃ for 12 hours to obtain a fluororubber composite material resistant to supercritical CO2 corrosion. During the above preparation process, it is important to note that the total amount of carbon black, crosslinking agent, and co-crosslinking agent added each time should not exceed 10g. After each addition, the material should be cut from both sides and rolled to ensure thorough and uniform mixing with the colloid. After the final addition, at least 10 triangular wraps should be made before thinning. This preparation method is simple, easy to control, and suitable for large-scale production.

[0038] The present invention also provides the application of the rubber composite material of any of the above technical solutions as a sealing element in a supercritical CO2 environment with a temperature of 130°C and a pressure of 9MPa.

[0039] In some embodiments, the rubber composite material is used for sealing critical equipment in CCUS (Carbon Capture, Utilization, and Sequestration) engineering technologies. This rubber composite material can be used for long-term operation and sealing of critical equipment in supercritical carbon dioxide working media. It solves the technical problem that rubber sealing materials manufactured using traditional processing techniques cannot meet the requirements for resistance to supercritical carbon dioxide corrosion. By constructing a coupled network structure in the rubber matrix through the synergistic effect of chemical crosslinking generated by a crosslinking agent and physical crosslinking of organo-montmorillonite (OMMT), the prepared rubber composite material exhibits excellent resistance to supercritical carbon dioxide corrosion in a supercritical carbon dioxide medium at 130℃ × 9MPa, meeting the application requirements for corrosion resistance of rubber sealing materials in actual working conditions under supercritical CO2 media.

[0040] To provide a clearer and more detailed description of the rubber composite material, its preparation method, and its application provided in the embodiments of the present invention, the following description will be based on specific embodiments.

[0041] Example 1 100 parts by weight of fluororubber were fed into a two-roll mill for raw rubber plasticizing. Then, 0.25 parts of modified OMMT, 23 parts of carbon black, 2.5 parts of crosslinking agent, and 8 parts of co-crosslinking agent were added sequentially. The mixture was then thoroughly mixed to obtain a compound. The compound was allowed to stand at room temperature for 12 hours to eliminate any stress that might have occurred during mixing. The cooled compound was then subjected to a first-stage vulcanization at 170℃ / 15MPa for 7 minutes, followed by a second-stage vulcanization at 200℃ for 12 hours to obtain an FKM composite material resistant to supercritical CO2 corrosion.

[0042] The fluororubber mentioned above is FKM600S, the carbon black is spray-dried carbon black, the crosslinking agent is 2,5-dimethyl-2,5-di-tert-butylperoxyhexane (DBPH), the co-crosslinking agent is triallyl isocyanate (TAIC), the modified OMMT is SMP, and the interlayer spacing of the modified OMMT is 1.26 nm.

[0043] Specific preparation methods include: (1) Mold and plasticize 100 parts by weight of rubber (fluororubber), and slowly add organomontmorillonite (OMMT) and carbon black in sequence, and mix for 30 minutes; (2) Add crosslinking agent and co-crosslinking agent to the above system in batches, mix for 30 minutes, and then uniformly sheet the mixture to obtain the compound and cool it. (3) The cooled compound was vulcanized for 7 minutes at 170℃ / 15MPa on a vulcanizing machine, and then vulcanized for 12 hours at 200℃ to obtain a rubber composite material resistant to supercritical carbon dioxide corrosion.

[0044] In the above preparation process, the total amount of carbon black, crosslinking agent and co-crosslinking agent added each time shall not exceed 10g, and after each addition, the material shall be cut with left and right cuts and rolled up to ensure that the material and colloid are fully and evenly mixed. After the last addition is completed, the material shall be rolled up at least 10 times in a triangular shape and then passed through thinly.

[0045] Example 2 Same as Example 1, except that the modified OMMT added is different. The added OMMT is SMF-LV with an interlayer spacing of 1.27 nm.

[0046] Example 3 Same as Example 1, except that the modified OMMT added is different. The added OMMT is SMDK18 with an interlayer spacing of 2.01 nm.

[0047] Example 4 Same as Example 1, except that the modified OMMT added is different. The added OMMT is SMDK10 with an interlayer spacing of 3.46 nm.

[0048] Comparative Example 1 Same as Example 4, except that 3 parts of modified OMMT were added.

[0049] Comparative Example 2 Same as Example 1, except that no modified OMMT was added.

[0050] Comparative Example 3 Similar to Comparative Example 2, except that the amount of crosslinking agent used was 7 parts.

[0051] Comparative Example 4 Similar to Comparative Example 2, except that the amount of crosslinking agent used was 12 parts.

[0052] Comparative Example 5 Similar to Comparative Example 2, except that the amount of crosslinking agent used is 3 parts.

[0053] Comparative Example 6 100 parts by weight of hydrogenated nitrile butadiene rubber were fed into a two-roll mill for raw rubber plasticizing. Then, 1 part of softener stearic acid (SA), 5 parts of accelerator zinc oxide (ZnO), 0.75 parts of antioxidant 4,4′-bis(α,α′-dimethylbenzyl)diphenylamine (445), 0.75 parts of antioxidant (GM), 50 parts of carbon black (N550), 5 parts of crosslinking agent cumene peroxide (DCP), and 2 parts of co-crosslinking agent triallyl isocyanate (TAIC) were added sequentially. The mixture was then thoroughly mixed to obtain a compound. The compound was allowed to stand at room temperature for 12 hours to eliminate any stress that might have occurred during mixing. The cooled compound was then subjected to a first-stage vulcanization at 170℃ / 15MPa for 20 minutes, followed by a second-stage vulcanization at 150℃ for 4 hours to obtain the hydrogenated nitrile butadiene composite material.

[0054] Performance testing The physical properties of the hydrogenated nitrile rubber and fluororubber composites prepared in Examples 1-4 and Comparative Examples 1-6 were tested: the hardness was tested according to GB / T531.1-2008; the tensile properties were tested according to GB / T528-2009; the crosslinking density was calculated according to formulas (1) and (2); the corrosion resistance coefficient was calculated according to formula (3); the interlayer spacing was analyzed using a D-MAx2500 / PC X-ray diffractometer (XRD, Rigaku Corporation, Japan), with a radiation tube voltage of 40kV, a current of 100mA, a scanning range of 0.5°-20°, and a scanning rate of 1° / min. The Bragg equation (4) was used for calculation during the analysis.

[0055]

[0056] in, Ve The crosslinking density of the sample; V 0 represents the volume fraction of rubber at swelling equilibrium; m 0 represents the sample mass before swelling; m 1 and m 2 represents the sample mass before and after drying; f This represents the mass fraction of rubber in the vulcanized rubber. α This refers to the rate of change in the sample's own mass. r r The density of rubber is taken as 1.85 g / cm³. 3 ; r s The solvent density is taken as 0.902 g / cm³. 3 ; x The Huggins parameters for rubber and ethyl acetate are given. Vs. The value is the molar volume of ethyl acetate solvent, which is 98.4 mL / mol.

[0057]

[0058] In the formula s 0 represents the initial tensile strength. e 0 represents the initial elongation at break. s 1 represents the tensile strength after corrosion. e 1 represents the elongation at break after corrosion. l The higher the value, the stronger the resistance to supercritical CO2 corrosion.

[0059]

[0060] In the formula d It is the interlayer spacing of the OMMT (001) layer. i It is the diffraction angle. n =1, and l =0.154nm.

[0061] The testing conditions were as follows: the prepared test sample was placed in an autoclave, CO2 was injected into the autoclave, the pressure of the autoclave was increased to 9 MPa, and the temperature was set to 130℃. The experimental conditions were close to the actual working conditions. Samples were taken at 48h, 96h, 144h, 168h, and 192h and the performance was tested.

[0062] The test results are shown in Table 1.

[0063] Table 1 Comparison of corrosion resistance of rubber composite materials obtained from comparative examples and embodiments (130℃×9MPa)

[0064] As shown in Table 1, under the same supercritical CO2 medium corrosion conditions, Comparative Example 5 exhibits better corrosion resistance and mechanical properties than Comparative Example 6 and Comparative Example 5. That is, the supercritical CO2 corrosion resistance of fluororubber is better than that of hydrogenated nitrile rubber.

[0065] Based on Comparative Example 5, Comparative Examples 2-4 differed only in the amount of crosslinking agent, but their crosslinking densities increased sequentially. This indicates that, without the addition of a composite material, the crosslinking agent TAIC is the main factor affecting the crosslinking density, and the two are positively correlated.

[0066] As can be seen from the corrosion resistance coefficients and crosslinking densities of Comparative Examples 2-5 in Table 1, the crosslinking density of Comparative Example 4 is higher than that of Comparative Example 2, but the corrosion resistance coefficient of Comparative Example 2 is greater than that of Comparative Example 4. Therefore, moderate crosslinking can exhibit better corrosion resistance.

[0067] Based on Comparative Example 2, Examples 1-4 and Comparative Example 1 introduced OMMT lamellar particles with different interlayer spacings on the basis of Comparative Example 2. It can be seen from the data comparison in Table 1 that the corrosion resistance of FKM composite materials with different interlayer spacings of OMMT is also different. Moreover, the interlayer spacing of OMMT in Examples 1-4 is from small to large in sequence. It can be seen that the modified OMMT with large interlayer spacing brings better corrosion resistance to FKM composite materials.

[0068] In addition, Comparative Example 1 changed the amount of OMMT introduced based on Example 4. As can be seen from the data in the table, OMMT with a large interlayer spacing was introduced on the basis of moderate crosslinking. The crosslinking density of Comparative Example 1 was higher than that of Example 4, but its corrosion resistance coefficient was significantly lower than that of Example 4, which further confirms that moderate crosslinking is more beneficial to the corrosion resistance of the material.

[0069] Based on the above data, a suitable crosslinking density was optimized and screened from Comparative Examples 2-5, and Example 4 was prepared based on this. Example 4 introduces large interlayer spacing OMMT under moderate crosslinking, that is, under the synergistic effect of moderate chemical crosslinking initiated by the co-crosslinking agent and physical crosslinking caused by the two-dimensional lamellar particles, the fluororubber composite material of Example 4 exhibits the best corrosion resistance in high temperature, high pressure, and supercritical CO2 media.

Claims

1. A rubber composite material, characterized in that, The material comprises rubber, carbon black, crosslinking agent, co-crosslinking agent, and modified organomontmorillonite; the crosslinking density of the material obtained after mixing and vulcanizing the rubber, carbon black, crosslinking agent, and co-crosslinking agent is 7.3 × 10⁻⁶. -4 -7.8×10 -4 mol·cm -3 The interlayer spacing of the modified organomontmorillonite is 1.26-3.46 nm.

2. The rubber composite material according to claim 1, characterized in that, The rubber composite material comprises, by weight, 100 parts rubber, 15-30 parts carbon black, 2.5-4.5 parts crosslinking agent, 8-12 parts co-crosslinking agent, and 0.25-3 parts modified organomontmorillonite.

3. The rubber composite material according to claim 1, characterized in that, The rubber is selected from at least one of fluororubber, hydrogenated nitrile rubber, and fluoroether rubber; the fluororubber is selected from one of BR9151, FKM200S, FKM600S, FKM-246, or FEPM.

4. The rubber composite material according to claim 1, characterized in that, The carbon black is selected from at least one of spray-dried carbon black, super abrasion-resistant carbon black 220, semi-reinforcing carbon black N330, N550, N774, and N990.

5. The rubber composite material according to claim 1, characterized in that, The crosslinking agent is 2,5-dimethyl-2,5-di-tert-butylperoxyhexane or cumene peroxide, and the co-crosslinking agent is triallyl isocyanurate.

6. The rubber composite material according to claim 1, characterized in that, The modified organomontmorillonite is selected from one of SMP, SMF-LV, SMDK10, and SMDK18.

7. The rubber composite material according to claim 1, characterized in that, The crosslinking density of the rubber composite material is 8.59 × 10⁻⁶. -4 -9.68×10 -4 mol·cm -3 .

8. The method for preparing the rubber composite material according to any one of claims 1-7, characterized in that, include: The rubber is plasticized by open milling, and the modified organomontmorillonite and carbon black are added sequentially and mixed. Then, the crosslinking agent and co-crosslinking agent are added in batches and mixed. The mixture is then sheeted to obtain a compound and cooled. The cooled compound is subjected to a first-stage vulcanization and a second-stage vulcanization to obtain the rubber composite material.

9. The application of the rubber composite material according to any one of claims 1-7 as a sealant in a supercritical CO2 environment at a temperature of 130°C and a pressure of 9 MPa.

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