Modified reinforcing aid, method for preparing the same, and carbon dioxide corrosion resistant rubber material containing the same

Abstract

This invention discloses a modified reinforcing agent, its preparation method, and a carbon dioxide corrosion-resistant rubber material containing the same. The modified reinforcing agent is composed of 10-16 parts by weight of carboxylated carbon nanotubes, 24-50 parts by weight of carbon black oxide, 6-8 parts by weight of silica, 8-10 parts by weight of styrene, and 12-16 parts by weight of acrylate monomers. This invention, through graft modification of carbon nanotubes, carbon black, and silica, not only reinforces the material using these materials but also allows the grafted polymers to fill the spaces between rubber macromolecular chains. Furthermore, the grafted polymers can crosslink with the rubber macromolecular chains, further increasing the structural complexity of the rubber material and thus making it more difficult for carbon dioxide molecules to penetrate into the rubber material.

Description

Technical Field

[0001] This invention belongs to the field of rubber technology. Specifically, it relates to a modified reinforcing agent, its preparation method, and a carbon dioxide corrosion-resistant rubber material containing the same. Background Technology

[0002] While carbon dioxide flooding (CCF) technology can achieve the dual benefits of increased oil production and carbon sequestration, the rubber packers in packers are susceptible to sealing failure due to carbon dioxide corrosion, especially in supercritical carbon dioxide environments, where the corrosion resistance of existing rubber materials used in packer fabrication significantly decreases. In the absence of entirely new sealing materials, combining existing materials has become a key research and development approach for carbon dioxide-resistant rubber materials. When developing new carbon dioxide-resistant rubber materials, researchers typically combine existing fluororubber, hydrogenated nitrile rubber, and EPDM rubber with other materials and additives to achieve better resistance to carbon dioxide corrosion. Carbon dioxide corrodes rubber through the gaps between molecular chains; specifically, carbon dioxide molecules jump and advance through the polymer network using the instantaneous voids created by the thermal motion of rubber macromolecular segments. To reduce these instantaneous voids, it is necessary to increase the crosslinking degree and the filling density between macromolecular chains in the rubber material. Currently, increasing the crosslinking degree of rubber materials is usually achieved by increasing the amount of vulcanizing agent or extending the vulcanization time. However, increasing the amount of vulcanizing agent or extending the vulcanization time can easily lead to over-vulcanization, which will cause a significant decrease in the mechanical properties of rubber products. Therefore, how to improve the degree of crosslinking of rubber and the complexity of the crosslinking structure of rubber materials without increasing the amount of vulcanizing agent or extending the vulcanization time has become a research direction. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to provide a modified reinforcing agent and its preparation method, as well as a carbon dioxide corrosion resistant rubber material containing the same. The present invention modifies carbon nanotubes, carbon black, and silica by grafting, so that in addition to using carbon nanotubes, carbon black, and silica to reinforce the material, some of the polymers grafted on their surfaces can be used to fill the spaces between the rubber macromolecular chains. At the same time, some of the polymers grafted on their surfaces can be used to crosslink with the rubber macromolecular chains, further increasing the structural complexity of the rubber material and thus increasing the difficulty for carbon dioxide molecules to penetrate into the rubber material.

[0004] The modified reinforcing agent provided by the present invention is made of the following components: 10-16 parts by weight of carboxylated carbon nanotubes, 24-50 parts by weight of carbon black oxide, 6-8 parts by weight of silica, 8-10 parts by weight of styrene and 12-16 parts by weight of acrylate monomers. The carboxylated carbon nanotubes are carboxylated single-walled carbon nanotubes with a length of 5 to 10 μm. The silica is fumed silica with a particle size of 10-20 nm. Styrene is used for the irradiation grafting modification of carbon black oxide, while acrylate monomers are used for the irradiation grafting modification of carboxylated carbon nanotubes and silica.

[0005] In the modified reinforcing agent, the acrylate monomer is one or more of methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate.

[0006] Further, the acrylate monomers are a mixture of methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 1:(0.2-0.3):(0.2-0.3):(0.3-0.4).

[0007] The above-mentioned modified reinforcing agent is prepared by a method including the following steps: 1) Carboxylated carbon nanotubes and a first part of silica were ultrasonically dispersed in anhydrous ethanol to obtain a first mixed solution, carbon black oxide was ultrasonically dispersed in anhydrous ethanol to obtain a second mixed solution, and a second part of silica was ultrasonically dispersed in anhydrous ethanol to obtain a third mixed solution; wherein the weight ratio of the first part of silica to the second part of silica was (3-4):(1-2). 2) Add 80-90 wt% of acrylate monomers to the first mixed solution prepared in step 1) and stir until homogeneous to obtain the fourth mixed solution; add styrene to the second mixed solution and stir until homogeneous to obtain the fifth mixed solution; add the remaining acrylate monomers to the third mixed solution and stir until homogeneous to obtain the sixth mixed solution. 3) The fourth, fifth and sixth mixed solutions were irradiated and grafted to modify them respectively. Then the irradiated fourth and sixth mixed solutions were mixed and sonicated. The irradiated fifth mixed solution was added and stirred evenly. Then the mixture was filtered and dried to obtain the modified reinforcing agent.

[0008] In step 1) of the above method, when preparing the first mixed solution, 20-30 wt% of carboxylated carbon nanotubes are first ultrasonically dispersed in anhydrous ethanol, then 30-40 wt% of the first part of silica is added and ultrasonicated for 1-3 min, then 40-60 wt% of carboxylated carbon nanotubes are added and ultrasonicated for another 3-5 min, then 40-50 wt% of the first part of silica is added and ultrasonicated for another 5-8 min, then the remaining carboxylated carbon nanotubes are added and ultrasonicated for another 8-10 min, then the remaining first part of silica is added and ultrasonicated for another 10-12 min to obtain the first mixed solution.

[0009] Further, in step 1) of the above method, when preparing the first mixed solution, 24-28 wt% of carboxylated carbon nanotubes are first ultrasonically dispersed in anhydrous ethanol, then 32-36 wt% of the first part of silica is added and ultrasonicated for 1-2 min, then 44-56 wt% of carboxylated carbon nanotubes are added and ultrasonicated for another 3-5 min, then 42-46 wt% of the first part of silica is added and ultrasonicated for another 6-8 min, then the remaining carboxylated carbon nanotubes are added and ultrasonicated for another 9-10 min, then the remaining first part of silica is added and ultrasonicated for another 11-12 min to obtain the first mixed solution.

[0010] Carboxylated carbon nanotubes are prepared by introducing carboxyl functional groups into hollow tubular structures formed by seamlessly rolling single or multiple layers of graphene. When carboxylated carbon nanotubes are ultrasonically dispersed and mixed with silica, the addition of anhydrous ethanol in batches followed by ultrasonication facilitates the uniform dispersion of silica within the carboxylated carbon nanotubes. This also promotes the adsorption of silica particles at one end of the carboxylated carbon nanotubes, reducing silica agglomeration. Furthermore, it facilitates the formation of a composite structure of modified reinforcing agent particles after modification with acrylate monomers. This composite structure contains both carboxylated carbon nanotubes grafted with acrylate monomers and silica grafted with acrylate monomers, with the carboxylated carbon nanotubes and silica particles physically adsorbed together. When this composite structure of modified reinforcing agent particles is added to rubber products, it creates more complex gaps between the particles, the rubber macromolecular chains, and other additives, further hindering the penetration of carbon dioxide into the rubber.

[0011] In the above method, the weight ratio of the first part of silica to the second part of silica is (7-8):(2-3).

[0012] Step 3) of the above method is as follows: the fourth mixed solution, the fifth mixed solution, and the sixth mixed solution are placed in... 60 Irradiate with a Co radioactive source, then mix the irradiated fourth and sixth mixed solutions and sonicate for 15-30 minutes, then add the irradiated fifth mixed solution and stir evenly, then filter and dry to obtain the modified reinforcing agent. The absorbed dose is 10–800 kGy.

[0013] Silica contains silanol groups on its surface, which easily form hydrogen bonds and aggregate, limiting the amount of silica used or increasing the difficulty of rubber compounding. In this invention, a portion of silica is grafted and modified with carboxylated carbon nanotubes, while another portion is grafted and modified separately. The specific objectives are twofold: first, to construct reinforcing agent particles with a relatively complex surface structure, increasing the complexity of the internal channels of the rubber crosslinking network; second, to use the separately grafted silica as a supplementary reinforcing agent to fill the gaps between larger reinforcing agent particles, further increasing the complexity of the internal channels of the rubber crosslinking network. If all silica is grafted and modified together with carboxylated carbon nanotubes, only larger reinforcing agent particles will be formed; if all silica is grafted and modified separately, only smaller reinforcing agent particles will be formed. The reinforcing agent particles produced in both cases result in a significantly lower complexity of the internal channels of the rubber crosslinking network compared to the technical solution selected in this invention.

[0014] The present invention also provides a rubber material resistant to carbon dioxide corrosion.

[0015] The carbon dioxide corrosion-resistant rubber material provided by this invention comprises the following components: hydrogenated nitrile butadiene rubber, the above-mentioned modified reinforcing agents, plasticizers, oxides, antioxidants, accelerators, vulcanizing agents, and scorching inhibitors. Of which, by weight, hydrogenated nitrile rubber 100-120; modified reinforcing agent 120-150; plasticizer 2-6; oxide 6-10; antioxidant 6-10; accelerator 1-2; vulcanizing agent 2-5; scorch inhibitor 1-2; The oxide is a mixture of zinc oxide and magnesium oxide in a molar ratio of (4-7):(1-3), and the particle size of the oxide can be 30-50 nm. The vulcanizing agent is dicumyl peroxide or / and bis-tert-butyl dicumyl peroxide; The accelerator is one or more of benzoyl peroxide, diisopropylbenzene hydrogen peroxide, and methyl ethyl ketone peroxide; The antioxidant is antioxidant 445; The plasticizer is liquid nitrile rubber; The anti-scorching agent is anti-scorching agent CTP and / or rubber anti-scorching agent YG-1.

[0016] The application of the aforementioned carbon dioxide corrosion-resistant rubber material in carbon dioxide flooding packers also falls within the scope of protection of this invention.

[0017] The technical solution of the present invention achieves the following beneficial technical effects: 1. By grafting carbon nanotubes, carbon black, and silica, these materials can be incorporated into the rubber crosslinking network during the rubber vulcanization process. This increases the degree of crosslinking in the rubber and reduces the gaps between rubber macromolecular chains. Even if transient gaps are created in the rubber macromolecular chain segments due to thermal motion, the grafted polymer can partially or completely fill these gaps, thereby delaying the penetration of carbon dioxide molecules into the rubber material.

[0018] 2. By grafting carbon nanotubes with some silica, the adsorption capacity of carbon nanotubes can be used to construct an irregularly shaped particle, which increases the permeation path length of carbon dioxide molecules and delays the penetration of carbon dioxide molecules into the interior of rubber materials. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0020] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0021] The carboxylated carbon nanotubes used in the following examples are 5-10 μm long carboxylated single-walled carbon nanotubes, which are products of Sichuan Kenye Technology Development Co., Ltd., model H-S3.

[0022] The silica used in the following examples is fumed silica with a particle size of 10-20 nm, which is a product of Degussa, model A200, trade name AEROSIL.

[0023] Example 1: Preparation of Modified Reinforcing Agent The modified reinforcing agent in this embodiment is made from the following components: 10 parts by weight of carboxylated carbon nanotubes, 24 parts by weight of carbon black oxide, 6 parts by weight of silica, 8 parts by weight of styrene, and 12 parts by weight of acrylate monomers; wherein, the carboxylated carbon nanotubes are carboxylated single-walled carbon nanotubes with a length of 5-10 μm, the silica is fumed silica with a particle size of 10-20 nm, and the acrylate monomers are methyl acrylate.

[0024] The specific preparation method includes the following steps: Step 1) Prepare the ingredients according to the formula; Step 2) Disperse carboxylated carbon nanotubes and the first part of silica in anhydrous ethanol by ultrasonication to obtain a first mixed solution (added all at once), disperse carbon black by ultrasonication (5 min) in anhydrous ethanol to obtain a second mixed solution, and disperse the second part of silica by ultrasonication (5 min) in anhydrous ethanol to obtain a third mixed solution; wherein the weight ratio of the first part of silica to the second part of silica is 3:1. Step 3) Add 80 wt% of acrylate monomers to the first mixed solution prepared in Step 2) and stir until homogeneous to obtain the fourth mixed solution; add styrene to the second mixed solution prepared in Step 2) and stir until homogeneous to obtain the fifth mixed solution; add the remaining acrylate monomers to the third mixed solution prepared in Step 2) and stir until homogeneous to obtain the sixth mixed solution. Step 4) Place the fourth, fifth, and sixth mixed solutions into separate containers. 60 Irradiate the sample with a Co radiation source at an absorbed dose of 50 ± 2 kGy. Then, mix the irradiated fourth and sixth mixed solutions and sonicate for 30 min. Next, add the irradiated fifth mixed solution and stir until homogeneous. Then, filter and dry to obtain the modified reinforcing agent.

[0025] Example 2: Preparation of Modified Reinforcing Agent The modified reinforcing agent in this embodiment is made from the following components: 12 parts by weight of carboxylated carbon nanotubes, 36 parts by weight of carbon black oxide, 8 parts by weight of silica, 10 parts by weight of styrene, and 14 parts by weight of acrylate monomers; wherein, the carboxylated carbon nanotubes are carboxylated single-walled carbon nanotubes with a length of 5-10 μm, the silica is fumed silica with a particle size of 10-20 nm, and the acrylate monomers are ethyl acrylate.

[0026] The preparation method of the modified reinforcing agent in this embodiment is the same as that in Example 1.

[0027] Example 3: Preparation of Modified Reinforcing Agent The modified reinforcing agent in this embodiment is made from the following components: 16 parts by weight of carboxylated carbon nanotubes, 50 parts by weight of carbon black oxide, 8 parts by weight of silica, 10 parts by weight of styrene, and 16 parts by weight of acrylate monomers; wherein, the carboxylated carbon nanotubes are carboxylated single-walled carbon nanotubes with a length of 5-10 μm, the silica is fumed silica with a particle size of 10-20 nm, and the acrylate monomers are butyl acrylate.

[0028] The difference between the modified reinforcing agent preparation method in this embodiment and the modified reinforcing agent preparation method in Example 1 is that the weight ratio of the first part of silica to the second part of silica is 4:1; and the acrylate monomers added to the first mixed solution account for 90 wt% of all acrylate monomers.

[0029] Example 4: Preparation of Modified Reinforcing Agent The modified reinforcing agent in this embodiment is made from the following components: 16 parts by weight of carboxylated carbon nanotubes, 50 parts by weight of carbon black oxide, 8 parts by weight of silica, 10 parts by weight of styrene, and 16 parts by weight of acrylate monomers; wherein, the carboxylated carbon nanotubes are carboxylated single-walled carbon nanotubes with a length of 5-10 μm, the silica is fumed silica with a particle size of 10-20 nm, and the acrylate monomers are methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate mixed in a molar ratio of 1:0.2:0.2:0.3.

[0030] The method for preparing the modified reinforcing agent in this embodiment differs from that in Example 1 in that: the weight ratio of the first part of silica to the second part of silica is 7:3; and the acrylate monomers added to the first mixed solution account for 90 wt% of all acrylate monomers.

[0031] Example 5: Preparation of Modified Reinforcing Agent The modified reinforcing agent in this embodiment is made from the following components: 16 parts by weight of carboxylated carbon nanotubes, 48 ​​parts by weight of carbon black oxide, 8 parts by weight of silica, 10 parts by weight of styrene, and 16 parts by weight of acrylate monomers; wherein, the carboxylated carbon nanotubes are carboxylated single-walled carbon nanotubes with a length of 5-10 μm, the silica is fumed silica with a particle size of 10-20 nm, and the acrylate monomers are methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate mixed in a molar ratio of 1:0.3:0.3:0.4.

[0032] The specific preparation method includes the following steps: Step 1) Prepare the ingredients according to the formula; Step 2) Carboxylated carbon nanotubes and the first part of silica are ultrasonically dispersed in anhydrous ethanol to obtain a first mixed solution. Carbon black oxide is ultrasonically dispersed in anhydrous ethanol to obtain a second mixed solution. The second part of silica is ultrasonically dispersed in anhydrous ethanol to obtain a third mixed solution. The weight ratio of the first part of silica to the second part of silica is 7:3. The specific preparation operation of the first mixed solution is as follows: First, 26 wt% of carboxylated carbon nanotubes are ultrasonically dispersed in anhydrous ethanol. Then, 32 wt% of the first part of silica is added and ultrasonicated for 2 min. Next, 50 wt% of carboxylated carbon nanotubes are added and ultrasonicated for another 5 min. Then, 45 wt% of the first part of silica is added and ultrasonicated for another 5 min. Next, the remaining carboxylated carbon nanotubes are added and ultrasonicated for another 10 min. Finally, the remaining first part of silica is added and ultrasonicated for another 10 min to obtain the first mixed solution. Step 3) Add 80 wt% of acrylate monomers to the first mixed solution prepared in Step 2) and stir until homogeneous to obtain the fourth mixed solution; add styrene to the second mixed solution prepared in Step 2) and stir until homogeneous to obtain the fifth mixed solution; add the remaining acrylate monomers to the third mixed solution prepared in Step 2) and stir until homogeneous to obtain the sixth mixed solution. Step 4) Place the fourth, fifth, and sixth mixed solutions into separate containers. 60 Irradiate the sample with a Co radiation source at an absorbed dose of 50 ± 2 kGy. Then, mix the irradiated fourth and sixth mixed solutions and sonicate for 30 min. Next, add the irradiated fifth mixed solution and stir until homogeneous. Then, filter and dry to obtain the modified reinforcing agent.

[0033] Example 6: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The carbon dioxide corrosion-resistant rubber material in this embodiment is made of 100 parts by weight of hydrogenated nitrile rubber, 120 parts by weight of modified reinforcing agent, 2 parts by weight of plasticizer, 6 parts by weight of oxide, 6 parts by weight of antioxidant, 1 part by weight of accelerator, 2 parts by weight of vulcanizing agent, and 2 parts by weight of scorching inhibitor; wherein, the modified reinforcing agent is the modified reinforcing agent prepared in Example 1, the oxide is a mixture of zinc oxide and magnesium oxide in a molar ratio of 7:2, the oxide particle size is 30-50 nm, and the vulcanizing agent... The accelerator is dicumyl peroxide, the antioxidant is benzoyl peroxide, the antioxidant is antioxidant 445, the plasticizer is liquid nitrile rubber, and the scorching inhibitor is scorching inhibitor CTP; the acrylonitrile content of the hydrogenated nitrile rubber is 39% to 44%, the saturation of the hydrogenated nitrile rubber is 92% to 99%, and the Mooney viscosity ML1+4 (100°C) of the raw rubber of the hydrogenated nitrile rubber is 60 to 100. The hydrogenated nitrile rubber mentioned in this embodiment and subsequent embodiments is Therban 4367.

[0034] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is as follows: the rubber compound is prepared by mixing in an open mill, the cooling water is turned on, the roller temperature is kept not higher than 50°C, the hydrogenated nitrile rubber is plasticized several times in the open mill, then the plasticizer, antioxidant and anti-scorching agent are mixed for 5 minutes, then the modified reinforcing agent and oxide are added and mixed for 5 minutes, then the accelerator and vulcanizing agent are added and mixed for 3 minutes, then the sheet is thinned 6 times and then plate-cured at 160°C for 10 minutes at a pressure of 15 MPa to obtain sample 1.

[0035] Example 7: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The difference between the carbon dioxide corrosion resistant rubber material in this embodiment and the carbon dioxide corrosion resistant rubber material in Example 6 is that the modified reinforcing agent used to prepare the carbon dioxide corrosion resistant rubber material in this embodiment is the modified reinforcing agent prepared in Example 2.

[0036] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in Sample 2.

[0037] Example 8: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The difference between the carbon dioxide corrosion resistant rubber material in this embodiment and the carbon dioxide corrosion resistant rubber material in Example 6 is that the modified reinforcing agent used to prepare the carbon dioxide corrosion resistant rubber material in this embodiment is the modified reinforcing agent prepared in Example 3.

[0038] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in Sample 3.

[0039] Example 9: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The difference between the carbon dioxide corrosion resistant rubber material in this embodiment and the carbon dioxide corrosion resistant rubber material in Example 6 is that the modified reinforcing agent used to prepare the carbon dioxide corrosion resistant rubber material in this embodiment is the modified reinforcing agent prepared in Example 4.

[0040] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in Sample 4.

[0041] Example 10: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The difference between the carbon dioxide corrosion resistant rubber material in this embodiment and the carbon dioxide corrosion resistant rubber material in Example 6 is that the modified reinforcing agent used to prepare the carbon dioxide corrosion resistant rubber material in this embodiment is the modified reinforcing agent prepared in Example 5.

[0042] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in sample 5.

[0043] Example 11: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The carbon dioxide corrosion-resistant rubber material in this embodiment is made of 120 parts by weight of hydrogenated nitrile rubber, 120 parts by weight of modified reinforcing agent, 6 parts by weight of plasticizer, 7 parts by weight of oxide, 9 parts by weight of antioxidant, 1.5 parts by weight of accelerator, 5 parts by weight of vulcanizing agent and 1.5 parts by weight of scorch inhibitor; wherein, the modified reinforcing agent is the modified reinforcing agent prepared in Example 5, the oxide is a mixture of zinc oxide and magnesium oxide in a molar ratio of 7:2, the oxide particle size is 30-50 nm, the vulcanizing agent is dicumyl peroxide, the accelerator is benzoyl peroxide, the antioxidant is antioxidant 445, the plasticizer is liquid nitrile rubber, and the scorch inhibitor is scorch inhibitor CTP.

[0044] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in Sample 6.

[0045] Example 12: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The carbon dioxide corrosion-resistant rubber material in this embodiment is made of 110 parts by weight of hydrogenated nitrile rubber, 130 parts by weight of modified reinforcing agent, 5 parts by weight of plasticizer, 9 parts by weight of oxide, 7 parts by weight of antioxidant, 1.8 parts by weight of accelerator, 4 parts by weight of vulcanizing agent and 1.3 parts by weight of scorch inhibitor. Among them, the modified reinforcing agent is the modified reinforcing agent prepared in Example 5, the oxide is a mixture of zinc oxide and magnesium oxide in a molar ratio of 7:2, the oxide particle size is 30-50 nm, the vulcanizing agent is dicumyl peroxide, the accelerator is benzoyl peroxide, the antioxidant is antioxidant 445, the plasticizer is liquid nitrile rubber, and the scorch inhibitor is scorch inhibitor CTP.

[0046] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in sample 7.

[0047] Example 13: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The carbon dioxide corrosion-resistant rubber material in this embodiment is made of 120 parts by weight of hydrogenated nitrile rubber, 150 parts by weight of modified reinforcing agent, 5 parts by weight of plasticizer, 9 parts by weight of oxide, 8 parts by weight of antioxidant, 1.8 parts by weight of accelerator, 5 parts by weight of vulcanizing agent and 1.5 parts by weight of scorch inhibitor. Among them, the modified reinforcing agent is the modified reinforcing agent prepared in Example 5, the oxide is a mixture of zinc oxide and magnesium oxide in a molar ratio of 7:2, the oxide particle size is 30-50 nm, the vulcanizing agent is dicumyl peroxide, the accelerator is benzoyl peroxide, the antioxidant is antioxidant 445, the plasticizer is liquid nitrile rubber, and the scorch inhibitor is scorch inhibitor CTP.

[0048] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in sample 8.

[0049] Example 14: Preparation of Carbon Dioxide Corrosion Resistant Rubber Material The difference between the carbon dioxide corrosion resistant rubber material in this embodiment and the carbon dioxide corrosion resistant rubber material in Example 13 is that the modified reinforcing agent used to prepare the carbon dioxide corrosion resistant rubber material in this embodiment is prepared by the method of preparing the modified reinforcing agent in Example 1, and the raw materials of the modified reinforcing agent in this embodiment are the same as those of the modified reinforcing agent used in Example 13.

[0050] The preparation method of the carbon dioxide corrosion resistant rubber material in this embodiment is the same as that in Example 6, resulting in sample 9.

[0051] Comparative Example 1 The difference between the carbon dioxide corrosion resistant rubber material in this comparative example and the carbon dioxide corrosion resistant rubber material in Example 13 is that the reinforcing agent used is a mixture of 16 parts by weight of carboxylated carbon nanotubes, 48 ​​parts by weight of carbon black oxide, and 8 parts by weight of silica.

[0052] The preparation method of the carbon dioxide corrosion resistant rubber material in this comparative example is the same as that in Example 6.

[0053] Comparative Example 2 The difference between the carbon dioxide corrosion-resistant rubber material in this comparative example and the carbon dioxide corrosion-resistant rubber material in Example 13 is that the reinforcing agent used is carbon black oxide.

[0054] The preparation method of the carbon dioxide corrosion resistant rubber material in this comparative example is the same as that in Example 6.

[0055] The following performance tests were performed on the carbon dioxide corrosion-resistant rubber materials prepared in Examples 6-14 and Comparative Examples 1-2: (1) Tear strength: GB / T 529 Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser type, right angle and crescent type specimens) (2) Tensile strength and elongation at break: GB / T 528 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber; (3) Shore hardness: GB / T 531 Test method for indentation hardness of vulcanized rubber or thermoplastic rubber Part 1: Calculation of Shore hardness (Shore hardness) (4) Resistance to carbon dioxide corrosion: NACE™ 0187—2003 Evaluation of elastomer materials in acidic media, test conditions: pressure 35MPa, temperature 120℃, test period 168h, gas phase is pure CO2, liquid phase is distilled water.

[0056]

[0057] Among them, samples 1 to 9 are samples made from the carbon dioxide corrosion resistant rubber materials in Examples 6 to 14, respectively; comparative sample 1 is a sample made from the carbon dioxide corrosion resistant rubber material in Comparative Example 1; and comparative sample 2 is a sample made from the carbon dioxide corrosion resistant rubber material in Comparative Example 2.

[0058] As shown in Table 1, when the grafted modified reinforcing agent is used as a reinforcing agent for carbon dioxide corrosion resistant rubber materials, the physical properties and corrosion resistance of the materials are significantly improved. Furthermore, the stepwise mixing of carboxylated carbon nanotubes and silica before grafting modification effectively improves the uniformity of silica adsorption on carboxylated carbon nanotubes. This results in the grafted modified silica and grafted carboxylated carbon nanotubes becoming entangled, forming a composite particle. This composite particle, within the cross-linked structure of the carbon dioxide corrosion resistant rubber material, can not only cross-link with the rubber macromolecular chains but also become entangled with them through the carboxylated carbon nanotubes and the grafted polymer molecular chains on the silica. This makes the path of instantaneous voids generated by thermal motion within the rubber material more tortuous and prone to closing due to thermal motion. Consequently, it increases the difficulty for carbon dioxide molecules to enter the rubber interior through the voids between the rubber macromolecular chains, thus reducing the permeation rate of carbon dioxide into the rubber.

[0059] Analysis of the data recorded in Table 1 shows that when modifying rubber materials, the particle shape and structure of reinforcing agents can be improved. In addition to using sheet-like reinforcing agents (existing technology), grafting modification can be used to grow linear polymer molecular chains on the reinforcing agent particles (referring to the irradiation grafting modification of this invention). This allows the modified reinforcing agent to modify the internal cross-linked structure of the rubber material, making the pathways formed by the gaps between the rubber macromolecular chains and cross-linked chains more complex. It also increases the difficulty for carbon dioxide molecules to penetrate from the surface of the rubber material into the interior of the rubber material, and can also ensure that the rubber material has good tear resistance. This feature is significantly better than the effect brought by sheet-like reinforcing agents.

[0060] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. A modified reinforcing agent, made from raw materials comprising the following components: 10-16 parts by weight of carboxylated carbon nanotubes, 24-50 parts by weight of carbon black oxide, 6-8 parts by weight of silica, 8-10 parts by weight of styrene, and 12-16 parts by weight of acrylate monomers; wherein, The carboxylated carbon nanotubes are carboxylated single-walled carbon nanotubes with a length of 5-10 μm, and the silica is fumed silica with a particle size of 10-20 nm; styrene is used for the irradiation grafting modification of carbon black, and acrylate monomers are used for the irradiation grafting modification of carboxylated carbon nanotubes and silica.

2. The modified reinforcing agent according to claim 1, characterized in that, In the modified reinforcing agent, the acrylate monomer is one or more of methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate.

3. The modified reinforcing agent according to claim 2, characterized in that, The acrylate monomers are a mixture of methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 1:(0.2-0.3):(0.2-0.3):(0.3-0.4).

4. A method for preparing the modified reinforcing agent according to any one of claims 1-3, comprising the following steps: 1) ultrasonically dispersing carboxylated carbon nanotubes and a first portion of precipitated silica in anhydrous ethanol to obtain a first mixed solution, ultrasonically dispersing oxidized carbon black in anhydrous ethanol to obtain a second mixed solution, and ultrasonically dispersing a second portion of precipitated silica in anhydrous ethanol to obtain a third mixed solution; wherein, The weight ratio of the first part of silica to the second part of silica is (3-4):(1-2); 2) Add 80-90 wt% of acrylate monomers to the first mixed solution prepared in step 1) and stir until homogeneous to obtain the fourth mixed solution; add styrene to the second mixed solution and stir until homogeneous to obtain the fifth mixed solution; add the remaining acrylate monomers to the third mixed solution and stir until homogeneous to obtain the sixth mixed solution. 3) The fourth, fifth and sixth mixed solutions were irradiated and grafted to modify them respectively. Then the irradiated fourth and sixth mixed solutions were mixed and sonicated. The irradiated fifth mixed solution was added and stirred evenly. Then the mixture was filtered and dried to obtain the modified reinforcing agent.

5. The method according to claim 4, characterized in that, In step 1), when preparing the first mixed solution, 20-30 wt% of carboxylated carbon nanotubes are first ultrasonically dispersed in anhydrous ethanol. Then, 30-40 wt% of the first part of silica is added and ultrasonicated for 1-3 min. Next, 40-60 wt% of carboxylated carbon nanotubes are added and ultrasonicated for another 3-5 min. Then, 40-50 wt% of the first part of silica is added and ultrasonicated for another 5-8 min. Next, the remaining carboxylated carbon nanotubes are added and ultrasonicated for another 8-10 min. Finally, the remaining first part of silica is added and ultrasonicated for another 10-12 min to obtain the first mixed solution.

6. The method according to claim 4, characterized in that, Step 3) involves placing the fourth, fifth, and sixth mixed solutions into separate containers. 60 Irradiate with a Co radioactive source, then mix the irradiated fourth and sixth mixed solutions and sonicate for 15-30 minutes, then add the irradiated fifth mixed solution and stir evenly, then filter and dry to obtain the modified reinforcing agent; The absorbed dose is 10–800 kGy.

7. A carbon dioxide corrosion-resistant rubber material, comprising the following components: hydrogenated nitrile butadiene rubber, a modified reinforcing agent according to any one of claims 1-3 or a modified reinforcing agent prepared by the method according to any one of claims 4-6, a plasticizer, an oxide, an antioxidant, an accelerator, a vulcanizing agent, and a scorching inhibitor. in, By weight, hydrogenated nitrile rubber 100-120; modified reinforcing agent 120-150; plasticizer 2-6; oxide 6-10; antioxidant 6-10; accelerator 1-2; vulcanizing agent 2-5; scorch inhibitor 1-2.

8. The carbon dioxide corrosion-resistant rubber material according to claim 7, characterized in that, The oxide is a mixture of zinc oxide and magnesium oxide in a molar ratio of (4-7):(1-3), and the particle size of the oxide is 30-50 nm. The vulcanizing agent is dicumyl peroxide or / and bis-tert-butyl dicumyl peroxide; The accelerator is one or more of benzoyl peroxide, diisopropylbenzene hydrogen peroxide, and methyl ethyl ketone peroxide; The antioxidant is antioxidant 445; The plasticizer is liquid nitrile rubber; The anti-scorching agent is anti-scorching agent CTP and / or rubber anti-scorching agent YG-1.

9. The application of the carbon dioxide corrosion-resistant rubber material as described in claim 7 or 8 in a carbon dioxide flooding packer.

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