Functionalized monomer, raw material composition containing same for hydrogenated nitrile butadiene rubber, and preparation method for hydrogenated nitrile butadiene rubber

Abstract

Provided in the present invention are a functionalized monomer, a raw material composition containing same for hydrogenated nitrile butadiene rubber, and a preparation method for hydrogenated nitrile butadiene rubber. In the functionalized monomer, a hydroxyl group, an ether group, an ester group and a long-chain alkyl branched structure are integrated into one macromolecular chain; and the functionalized monomer subsequently serves as a raw material monomer for preparing hydrogenated nitrile butadiene rubber, which can obtain hydrogenated nitrile butadiene rubber having better cold resistance and oil resistance.

Description

Functionalized monomers and hydrogenated nitrile butadiene rubber raw material compositions containing them, and methods for preparing hydrogenated nitrile butadiene rubber.

[0001] Cross-reference information

[0002] This application claims priority to Chinese Patent Application No. 202411544614.6, filed on October 31, 2024, entitled "Functionalized Monomer and Hydrogenated Nitrile Butadiene Rubber Raw Material Composition Containing the Same and Method for Preparing Hydrogenated Nitrile Butadiene Rubber", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of hydrogenated nitrile butadiene rubber, specifically to a functionalized monomer, a hydrogenated nitrile butadiene rubber raw material composition containing the same, and a method for preparing hydrogenated nitrile butadiene rubber. Background Technology

[0004] Rubber components used in oil exploration equipment are prone to malfunction due to low temperatures, leading to safety hazards. While hydrogenated nitrile butadiene rubber (HNBR) is prepared by selectively hydrogenating the carbon-carbon double bonds in nitrile butadiene rubber, exhibiting excellent oil resistance and thermal stability, it also presents a serious drawback: the higher the degree of hydrogenation, the more long-range ordered tetrasubunit sequences its main chain structure contains, making it highly susceptible to crystallization. Furthermore, higher nitrile group content results in greater molecular chain polarity and decreased flexibility, ultimately leading to an increase in temperature glyc (Tg), resulting in poorer low-temperature resistance but better oil resistance; conversely, lower hydrogenation leads to lower Tg and better oil resistance. Therefore, there is a contradictory relationship between the oil resistance and low-temperature resistance of HNBR. Given the low-temperature operating environment of oil exploration equipment, extremely high requirements are placed on the oil resistance and low-temperature resistance of rubber sealing materials. Therefore, balancing the low-temperature resistance and oil resistance of HNBR is a key challenge.

[0005] In existing technologies, although the low-temperature resistance of hydrogenated nitrile butadiene rubber (NBR) is often improved to some extent by adding small-molecule modifiers, copolymerization, or blending, these methods still have certain limitations. Their preparation processes are complex, difficult to operate in practice, require large amounts of additives, are costly, and the low-temperature modification effect is not significant. Therefore, it is necessary to provide a new method for preparing low-temperature resistant hydrogenated NBR for oilfield applications to address these problems. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a functionalized monomer, a hydrogenated nitrile butadiene rubber raw material composition containing the monomer, and a method for preparing hydrogenated nitrile butadiene rubber, wherein the hydrogenated nitrile butadiene rubber exhibits better cold resistance and oil resistance.

[0007] To achieve the above objectives, the present invention provides a functionalized monomer having the structure shown in Formula I:

[0008] In Formula I, R1 is a C4-C8 alkyl group, and R2 is a C6-C12 straight-chain alkyl group; B is a 1,3-butadiene segment with a cap; L, m, and n represent the number of repeating units, where L≥1, n≥1, and m≥1, and L, m, and n are positive integers.

[0009] First, this functionalized monomer is a monomer with free radical reactivity. This monomer integrates hydroxyl, ether, ester and long-chain alkyl branched structures into a macromolecular chain. When used as a raw material monomer for the preparation of HNBR, the "cumulative effect" of the macromolecule can be fully utilized during the hydrogenation process, giving full play to the "group effect" of hydroxyl and ether groups and the "structural effect" of long-chain alkyl branching. This can effectively destroy the crystallinity of HNBR and greatly reduce the glass transition temperature (Tg) of HNBR. It can prepare cold-resistant and oil-resistant hydrogenated nitrile rubber for oil fields with a glass transition temperature Tg < -44℃. After low-temperature plasticizing and compounding, the products can be used for oil well exploration operations in extremely cold weather with a working temperature of -52℃.

[0010] Secondly, when this functionalized monomer is subsequently used as a raw material monomer for the preparation of HNBR, the introduction of its long-chain alkyl branched structure and flexible segment ether groups can effectively reduce the formation of gel during the synthesis of functionalized nitrile butadiene rubber, ensuring the stability of the polymerization process. It can effectively increase the content of ester groups, ether groups and cyano groups in HNBR, significantly improve the oil resistance of HNBR, reduce the volume deformation of HNBR in oilfield media, and prepare cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use with a raw rubber volume deformation rate of <+9%.

[0011] Furthermore, this functionalized monomer can achieve remarkable results in reducing the glass transition temperature (Tg) of HNBR and improving its oil resistance even at a low addition amount. It plays a good "synergistic effect" in achieving a balance between cold resistance and oil resistance, thus realizing the high efficiency of modification.

[0012] Furthermore, the number-average molecular weight of the functionalized monomers is 3000–4000.

[0013] The present invention also provides a hydrogenated nitrile rubber raw material composition, comprising a first component and a second component; the first component comprises acrylonitrile and butadiene monomers; the second component comprises the aforementioned functionalized monomers.

[0014] Furthermore, the hydrogenated nitrile butadiene rubber raw material composition includes a first component, a second component, and a third component; the first component includes acrylonitrile and 1,3-butadiene; the second component includes the aforementioned functionalized monomers; and the third component includes a terminator.

[0015] Furthermore, the first component also includes deionized water, emulsifier, activator, molecular weight regulator, oxygen scavenger, and first initiator.

[0016] Furthermore, the emulsifier is an emulsifier stable in acidic media, and can be selected from one or more combinations of alkyl sulfate emulsifiers, alkyl sulfonate emulsifiers, and aryl sulfonate emulsifiers. For example, it can be selected from potassium rosinate soap, methyl oleate soap, sodium pyrophosphate, fatty acids, disproportionated potassium rosinate, sodium fatty acid sodium salt (C8-C20). The amount of emulsifier used is conventional in the art and is not particularly limited in this invention. It is 2.0 to 6.0 parts, more preferably 4.0 to 5.0 parts, based on 100 parts of the total weight of monomers (acrylonitrile, 1,3-butadiene, and functionalized monomers).

[0017] Furthermore, the first initiator is a redox initiator, such as a combination of one or more of cumene hydroperoxide, dicumene hydroperoxide, isopropyl tert-butyl hydroperoxide, and isopropyl n-butyl hydroperoxide, preferably dicumene hydroperoxide. The amount of initiator used is conventional in the art and is not particularly limited in this invention. It is 0.05 to 0.40 parts, more preferably 0.10 to 0.25 parts, based on 100 parts of the total weight of monomers (acrylonitrile, 1,3-butadiene, and the total weight of functionalized monomers).

[0018] Furthermore, the activator is selected from one or a combination of two or more of the following: sodium formaldehyde sulfoxylate, ferrous sulfate, tetrasodium EDTA (tetrasodium EDTA salt), and ferric sodium EDTA (ferric sodium EDTA salt). The amount of activator used is conventional in the art and is not particularly limited in this invention. It is 0.1 to 0.3 parts, more preferably 0.15 to 0.20 parts, based on 100 parts of the total weight of monomers (acrylonitrile, 1,3-butadiene, and functionalized monomers).

[0019] Furthermore, the molecular weight regulator is a common regulator used in emulsion polymerization and can be selected from tert-dodecyl mercaptan and / or dodecyl mercaptan, preferably tert-dodecyl mercaptan. The amount of molecular weight regulator used is a conventional amount in the art, and the present invention does not impose a particular limitation. It is 0.5 to 3.0 parts, more preferably 1.0 to 2.0 parts, based on 100 parts of the total weight of monomers (acrylonitrile, 1,3-butadiene and functionalized monomers).

[0020] Furthermore, the oxygen scavenger is selected from one or more combinations of sodium dithionite, dimethyl ketoxime, isoascorbic acid, carbazide, and N-isopropylhydroxylamine, with sodium dithionite being preferred. The amount of oxygen scavenger used is conventional in the art and is not particularly limited in this invention; it is 0.01 to 0.05 parts per 100 parts of the total weight of monomers (acrylonitrile, 1,3-butadiene, and functionalized monomers).

[0021] Furthermore, the terminator is selected from one or more combinations of hydroxylamine sulfate, diethylhydroxylamine, 2,5-pentanebutylquinone, sodium dimethyl dithiocarbamate (sodium thimerosi), sodium nitrite (NaNO2), actinol reagent, and p-aminoazobenzene, with sodium thimerosi being preferred. The amount of terminator used is conventional in the art and is not particularly limited in this invention; it is 0.30 to 0.50 parts per 100 parts of the total weight of monomers (acrylonitrile, 1,3-butadiene, and the total weight of the functionalized monomers).

[0022] Furthermore, the weight ratio of deionized water, emulsifier, activator, acrylonitrile, molecular weight regulator, oxygen scavenger, 1,3-butadiene, functionalized monomer and terminator is 200-400: 2.0-6.0: 0.1-0.3: 30-38: 0.5-3.0: 0.01-0.05: 58-69: 1.0-4.0: 0.3-0.5.

[0023] This invention also provides a method for preparing hydrogenated nitrile butadiene rubber, which uses the aforementioned raw material composition to prepare hydrogenated nitrile butadiene rubber, and includes the following steps:

[0024] The first component is mixed to carry out the first polymerization reaction in the first stage. When the acrylonitrile conversion rate reaches 35% to 40%, the second component is added to the system to carry out the first polymerization reaction in the second stage. When the acrylonitrile conversion rate reaches 85% to 90%, the polymerization is terminated to obtain functionalized nitrile rubber.

[0025] Functionalized nitrile butadiene rubber (NBR) is dissolved in an organic solvent to form a liquid, which is then hydrogenated under the action of a catalyst to obtain hydrogenated NBR. Firstly, using the aforementioned functionalized monomers as raw materials for preparing HNBR, the "cumulative effect" of macromolecules can be fully utilized during hydrogenation, leveraging the "group effect" of hydroxyl and ether groups and the "structural effect" of long-chain alkyl branching. This effectively disrupts the crystallinity of HNBR, significantly reducing its glass transition temperature (Tg). This allows for the preparation of cold-resistant and oil-resistant hydrogenated NBR for oilfield use with a raw rubber glass transition temperature (Tg) < -44℃. After low-temperature plasticizing and compounding, the resulting products are suitable for oil well exploration operations in extremely cold weather conditions with a working temperature of -52℃.

[0026] Secondly, using the aforementioned functionalized monomers as raw material monomers for preparing HNBR, the introduction of long-chain alkyl branched structures and flexible segment ether groups can effectively reduce the formation of gels during the synthesis of functionalized nitrile butadiene rubber, ensure the stability of the polymerization process, effectively increase the content of ester groups, ether groups and cyano groups in HNBR, significantly improve the oil resistance of HNBR, reduce the volume deformation of HNBR in oilfield media, and prepare cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use with a raw rubber volume deformation rate of <+9%.

[0027] Furthermore, using the aforementioned functionalized monomers as raw material monomers for preparing HNBR, even with a relatively low addition amount, significant effects can be achieved in reducing the glass transition temperature (Tg) of HNBR and improving its oil resistance. This results in a good "synergistic effect" in achieving a balance between cold resistance and oil resistance, thus realizing the high efficiency of the modification.

[0028] In addition, the preparation method of the cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oil fields of the present invention is green and environmentally friendly, with significant modification effect, stable process, small product quality fluctuation, and suitable for industrial production.

[0029] Furthermore, the preparation method includes the following steps:

[0030] The first component is mixed to carry out the first polymerization reaction in the first stage. When the acrylonitrile conversion rate reaches 35% to 40%, the second component is added to the system to carry out the first polymerization reaction in the second stage. When the acrylonitrile conversion rate reaches 85% to 90%, the third component is added to the system to terminate the polymerization, and functionalized nitrile rubber is obtained.

[0031] Functionalized nitrile rubber is dissolved in an organic solvent to form a solution, and the solution is then subjected to a hydrogenation reaction under the action of a catalyst to obtain hydrogenated nitrile rubber.

[0032] In one optional embodiment, the preparation method of the above-mentioned hydrogenated nitrile rubber includes the following steps:

[0033] Step 1: Add deionized water, emulsifier, activator, acrylonitrile, and molecular weight regulator to the polymerization reactor. After vacuuming and nitrogen purging, add oxygen scavenger and 1,3-butadiene. Add the first initiator at low temperature (4-11℃) to carry out the first stage of polymerization reaction. When the acrylonitrile polymerization conversion rate reaches 35%-40%, add functionalized monomers to the system to carry out the second stage of polymerization reaction. When the acrylonitrile conversion rate reaches 85%-90%, add a terminator to the system to terminate the polymerization. Discharge the polymerization product system and allow it to coagulate, wash, and dry to obtain functionalized nitrile rubber.

[0034] Step 2: Dissolve the above-mentioned functionalized nitrile rubber in an organic solvent (e.g., chlorobenzene solution) to prepare a rubber solution. Then, add the rubber solution to a reaction vessel and introduce an inert gas (e.g., nitrogen) to purge the air from the reaction vessel. Next, purge the inert gas (e.g., nitrogen) from the reaction vessel with hydrogen. Then, under the protection of an inert gas (e.g., nitrogen), add a toluene solution of Grubbs II catalyst. Pressurize and heat the reaction to carry out the hydrogenation reaction. After the reaction is completed, cool the hydrogenation product system and allow it to condense and dry to obtain cold-resistant and oil-resistant hydrogenated nitrile rubber for oil fields.

[0035] Furthermore, the first polymerization reaction is a low-temperature emulsion polymerization, and the reaction temperature of the first polymerization reaction is 4–11°C.

[0036] Furthermore, the gel content in the obtained functionalized nitrile rubber is <1.5%.

[0037] Furthermore, the weight ratio of functionalized nitrile rubber to the toluene solution of Grubbs II catalyst is 100:0.05–0.25. The weight percentage of functionalized nitrile rubber in the solution is 3%–5%. The weight concentration of Grubbs II catalyst in the toluene solution is 6%–12%.

[0038] Furthermore, the treatment time for removing the inert gas from the reactor with hydrogen is 20–30 min; the pressure is increased to 13–16 MPa; the temperature is increased to 110–130 °C; and the hydrogenation reaction time is 10–13 h.

[0039] Furthermore, the degree of hydrogenation (HD) of cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oil fields is ≥96%.

[0040] Furthermore, the polymerization reactions of the present invention are carried out in an oxygen-free, anhydrous, and inert gas environment. The inert gas is nitrogen or a gas of a Group O element in the periodic table other than radon, with nitrogen being preferred.

[0041] Furthermore, the reactor of the present invention can be a loop reactor or a batch reactor, preferably a batch reactor.

[0042] Furthermore, the pressurization of the present invention is achieved by adding hydrogen gas. The amount of hydrogen gas added is well known to those skilled in the art, and the amount of hydrogen gas added is within the conventional addition range in the prior art. The present invention does not impose any particular limitation.

[0043] In a preferred embodiment, the functionalized monomer in the second component is prepared by the following steps: a second polymerization reaction is carried out by mixing diethylene glycol monovinyl ether, a first solvent, carbon chain methacrylate, a structure modifier, and a second initiator; then, 1,3-butadiene is added to the system for end-capping reaction, and the polymerization is terminated when no free monomer is present, to obtain a functionalized random copolymer; a third polymerization reaction is carried out by mixing the functionalized random copolymer, α-olefin, ethylene, a main catalyst, a co-catalyst, and a second solvent, to obtain the functionalized monomer.

[0044] In one optional embodiment, the method for preparing the above-mentioned functionalized monomer includes the following steps:

[0045] Step 1: In the polymerization reactor, argon gas is introduced to purge the system. The first solvent, diethylene glycol monovinyl ether, carbon chain methacrylate, structure modifier, and second initiator are added to the polymerization reactor in sequence. The temperature is raised to carry out the second polymerization reaction. Then, 1,3-butadiene is added to the polymerization reactor to carry out the end-capping reaction. The polymerization is terminated when no free monomers are present, and a glue solution is obtained. The glue solution is then wet-coagulated and dried to obtain a functionalized random copolymer.

[0046] Step 2: Inert gas is introduced into the high-pressure reactor for purging, a second solvent is added, the temperature is raised, and a co-catalyst is added under stirring. Stirring continues under inert gas protection. Then, the functionalized random copolymer, α-olefin, and main catalyst are added to the high-pressure reactor in sequence. At this time, ethylene is introduced to carry out the third reaction. After the reaction is completed, the product is centrifuged and dried to obtain the aforementioned functionalized monomer.

[0047] Furthermore, the weight ratio of diethylene glycol monovinyl ether, the first solvent, carbon chain methacrylate, the structure modifier, and 1,3-butadiene is 100:200-300:70-80:0.1-0.5:1.0-3.0;

[0048] The weight ratio of the second solvent, co-catalyst, functionalized random copolymer, α-olefin, and main catalyst is 200–300: 15–20: 4–8: 5–10: 1.

[0049] Furthermore, the carbon chain methacrylate is selected from one or more combinations of butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, and octyl methacrylate, with hexyl methacrylate being preferred.

[0050] Furthermore, the α-olefin may be selected from one or more combinations of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene, with 1-octene being preferred.

[0051] Furthermore, the main catalyst is a nickel-based complex catalyst, such as one or more combinations of nickel (1-naphthyl)[8-(diphenylphosphine)quinoline]chloride, trans-phenyl (di(triphenylphosphine))nickel bromide, and 2,5-dicarboxypyrrole dibromide, preferably trans-phenyl (di(triphenylphosphine))nickel bromide.

[0052] Furthermore, the cocatalyst is an alkylaluminoxane cocatalyst, such as methylaluminoxane (MAO) and / or ethylaluminoxane (EAO), with methylaluminoxane being preferred.

[0053] Furthermore, the second initiator is a hydrocarbon-based monolithium compound with the general structural formula RLi, wherein R is selected from one or more combinations of C1-20 saturated aliphatic hydrocarbon groups, C1-20 alicyclic hydrocarbon groups, and C1-20 aromatic hydrocarbon groups (two or more combinations refer to complex groups of the above groups), for example, one or more combinations of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthenelithium, cyclohexyllithium, and dodecyllithium, preferably n-butyllithium. The amount of the second initiator added is determined by the molecular weight of the designed polymer, which is known to those skilled in the art and will not be elaborated here.

[0054] Furthermore, the structure modifier is selected from one or more combinations of diethylene glycol dimethyl ether (2G), tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, diethylene glycol dimethyl ether (DME), and triethylamine.

[0055] Furthermore, the first solvent and the second solvent are each independently selected from one or more combinations of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene, and xylene, with cyclohexane being preferred. Attached Figure Description

[0056] Figure 1 is the infrared spectrum of hydrogenated nitrile rubber in Example 1 of the present invention.

[0057] Figure 2 is the NMR spectrum of the functionalized monomer in Example 1 of the present invention. Detailed Implementation

[0058] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this invention, the technical solution is described in detail below, but this should not be construed as limiting the scope of the invention. All raw materials used in the examples are industrial grade, purified before use, and have no other special requirements. The "parts" in the examples and comparative examples refer to parts by weight.

[0059] Raw material source:

[0060] Acrylonitrile, industrial polymer grade, China Petroleum Lanzhou Petrochemical Company;

[0061] 1,3-Butadiene, 99% purity, Lanzhou Petrochemical Company of China National Petroleum Corporation;

[0062] Diethylene glycol monovinyl ether, 99% purity, Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0063] Hexyl methacrylate, 99% purity, Suzhou Yake Technology Co., Ltd.

[0064] Ethylene, 99% purity, from Lanzhou Petrochemical Company of China National Petroleum Corporation;

[0065] 1-Octenene, purity 99.5%, Shandong Heze Xileng Chemical Co., Ltd.;

[0066] Grubbs II catalyst, 99% purity, Hubei Xinyuhong Biomedical Technology Co., Ltd.

[0067] Dicumyl peroxide, Lanzhou Additives Factory.

[0068] All other reagents are commercially available industrial products.

[0069] Molecular weight determination: Molecular weight was determined using a Waters 2414 gel permeation chromatography (GPC) system (Waters, Inc., USA). A polystyrene standard was used as the calibration curve. The mobile phase was tetrahydrofuran, the column temperature was 40℃, the sample concentration was 1 mg / mL, the injection volume was 50 μL, the elution time was 40 min, and the flow rate was 1 mL / min. -1 .

[0070] Determination of the degree of hydrogenation of HNBR: The degree of hydrogenation of hydrogenated nitrile butadiene rubber was calculated using 1H NMR spectroscopy. The main methods are as follows: 1. The product was completely dissolved in deuterated chloroform to prepare a 1H NMR spectroscopy sample; 2. The 1H NMR spectrum was measured and analyzed: The degree of hydrogenation of hydrogenated nitrile butadiene rubber was determined by 1H NMR spectroscopy and calculated according to the following methods: characteristic proton peak of 1,4-C=C-: 5.4 ppm, characteristic proton peak of 1,2-C=C-: 5.0 ppm, characteristic proton peak of saturated hydrocarbon: 1.25 ppm, characteristic proton peak of cyano-linked group: 2.5 ppm. The formula for calculating the degree of hydrogenation is as follows: Degree of hydrogenation HD (%) = 1 - Degree of unsaturation (U).

[0071] 1 Determination of HNBR functional groups: using proton nuclear magnetic resonance spectroscopy (NMR spectroscopy) 1 The functional groups of the functionalized monomers were analyzed and characterized by 1H NMR. The main methods are as follows: 1. The product was completely dissolved in deuterated chloroform to prepare a 1H NMR sample; 2. The 1H NMR spectrum was measured and analyzed.

[0072] Gel content test: Perform the method in standard SH / T1050-91.

[0073] Determination of glass transition temperature (Tg): The glass transition temperature of the product was measured using DSC. The instrument model was DSC1, manufactured by Mettler AG, Switzerland. The heating range was -80 to 80 °C, and the heating rate was 10 °C / min.

[0074] Oil resistance test: The method in standard GB / T1690-2010 shall be followed.

[0075] Example 1

[0076] This embodiment provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0077] (I) Preparation of functionalized monomers:

[0078] S1. Preparation of functionalized random copolymers: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas three times. 2000g cyclohexane, 1000g diethylene glycol monovinyl ether, 700g hexyl methacrylate, 1.0g THF, and 260mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 60℃ and the reaction was carried out for 50min. Finally, 10g 1,3-butadiene was added to the polymerization reactor for end-capping reaction for 20min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the functionalized random copolymer.

[0079] S2. Preparation of functionalized monomers: Nitrogen gas was purged three times in a 10L high-pressure reactor, 2000g of cyclohexane was added, and the temperature was raised to 80℃. Then, 150g of methylaluminoxane co-catalyst was added dropwise under uniform stirring at 600rpm. Stirring was continued for 20min under nitrogen protection. Subsequently, 40g of functionalized random copolymer, 50g of 1-octene, and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor in sequence. Ethylene was introduced, and the pressure was maintained at 13MPa for 5.0h. After the reaction was completed, the functionalized monomer (number average molecular weight Mn of 3000) was obtained by separation, devolatilization, and drying.

[0080] (II) Preparation of Functionalized Nitrile Rubber: 2000g of deionized water, 40g of sodium dodecylbenzene sulfonate soap, 1.3g of sodium formaldehyde sulfoxylate, 0.2g of EDTA-iron sodium salt, 300g of acrylonitrile monomer, and 10g of tert-dodecyl mercaptan were added to a 10L stirred pressure vessel. After evacuation, the mixture was purged with nitrogen three times. Then, 0.1g of sodium dithionite scavenger and 690g of 1,3-butadiene monomer were added. When the temperature of the polymerization vessel dropped to 4℃, 1.0g of dicumyl peroxide initiator was added to start the polymerization reaction. When the polymerization conversion rate reached 35%, 10g of functionalized monomer was added and the reaction continued. When the conversion rate reached 85%, 3.0g of sodium thiram termite was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to obtain functionalized nitrile rubber (gel content of 1.49%).

[0081] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfield Use: First, 200g of functionalized nitrile-butadiene rubber was dissolved in a chlorobenzene solution to prepare a 3% (by weight) rubber solution. Then, the solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 20 minutes. Then, under nitrogen protection, 0.10g of a toluene solution containing Grubbs II catalyst (6% by weight) was added. The hydrogen pressure in the reactor was increased to 13MPa, and the temperature was raised to 110℃. After reacting for 10 hours, the system was cooled, condensed, and vacuum dried to obtain cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfield use. Sampling and Analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0082] Figure 1 shows the infrared spectrum of the cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use in Example 1. As can be seen from Figure 1, the wavenumber is 2200–2350 cm⁻¹. -1 An absorption peak for the condensation vibration of the nitrile group (-CN) appears at a wavenumber of 1650–1800 cm⁻¹. -1 An absorption peak for the condensation vibration of the ester group appears at a wavenumber of 1200–1270 cm⁻¹. -1 An absorption peak for the condensation vibration of the ether group appears at a wavenumber of 1000–1080 cm⁻¹. -1 An absorption peak for the secondary condensation vibration of the alcohol group appears at a wavenumber of 700–720 cm⁻¹. -1 The presence of an absorption peak for saturated methylene groups indicates that the oilfield-grade, cold-resistant, and oil-resistant hydrogenated nitrile butadiene rubber prepared from functionalized monomers contains ester, hydroxyl, ether, nitrile, and saturated methylene groups.

[0083] Figure 2 shows the functional group NMR spectra of the functionalized monomers in Example 1. As can be seen from Figure 2, the unsaturated double bond hydrogens in the functionalized monomers have a signal at 1.95–2.02 ppm; the hydroxyl hydrogens in the functionalized monomers have a signal at 3.32–3.53 ppm; and the ester group hydrogens in the functionalized monomers have a signal at 2.42–2.51 ppm.

[0084] Example 2

[0085] This embodiment provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0086] (I) Preparation of functionalized monomers:

[0087] S1. Preparation of functionalized random copolymers: In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 2400g cyclohexane, 1000g diethylene glycol monovinyl ether, 720g hexyl methacrylate, 2.5g THF, and 265mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 63℃ and the reaction was carried out for 52min. Finally, 16g 1,3-butadiene was added to the polymerization reactor for end-capping reaction for 22min until no free monomers were present. The adhesive solution was wet-coagulated and dried to obtain the functionalized random copolymer.

[0088] S2. Preparation of functionalized monomers: Nitrogen gas was purged three times in a 10L high-pressure reactor, 2300g of cyclohexane was added, and the temperature was raised to 83℃. Then, 160g of methylaluminoxane co-catalyst was added dropwise under uniform stirring at 620rpm. Stirring was continued for 23min under nitrogen protection. Subsequently, 50g of functionalized random copolymer, 60g of 1-octene, and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor in sequence. Ethylene was introduced, and the pressure was maintained at 14MPa for 5.3h. After the reaction was completed, the functionalized monomer (number average molecular weight Mn of 3200) was obtained by separation, devolatilization, and drying.

[0089] (II) Preparation of Functionalized Nitrile Rubber: 2600g of deionized water, 42g of sodium dodecylbenzenesulfonate soap, 1.4g of sodium formaldehyde sulfoxylate, 0.3g of EDTA-iron sodium salt, 330g of acrylonitrile monomer, and 12g of tert-dodecyl mercaptan were added to a 10L stirred pressure vessel. After evacuation, the mixture was purged with nitrogen three times. Then, 0.3g of sodium dithionite, an oxygen scavenger, and 650g of 1,3-butadiene monomer were added. When the temperature of the polymerization vessel dropped to 8℃, 1.5g of dicumyl peroxide initiator was added to start the polymerization reaction. When the polymerization conversion rate reached 37%, 20g of functionalized monomer was added, and the reaction continued. When the conversion rate reached 87.0%, 4.0g of sodium thiram, a terminator, was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to obtain functionalized nitrile rubber (gel content of 1.46%).

[0090] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfield Use: First, 200g of functionalized nitrile-butadiene rubber was dissolved in a chlorobenzene solution to prepare a 3.5% (by weight) rubber solution. Then, the solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 23 minutes. Then, under nitrogen protection, 0.31g of a toluene solution containing Grubbs II catalyst (9% by weight) was added. The hydrogen pressure in the reactor was increased to 14MPa, and the temperature was raised to 120℃. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfield use. Sampling and Analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0091] Example 3

[0092] This embodiment provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0093] (I) Preparation of functionalized monomers:

[0094] S1. Preparation of functionalized random copolymers: In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 2800g cyclohexane, 1000g diethylene glycol monovinyl ether, 760g hexyl methacrylate, 3.8g THF, and 275mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 67℃ and the reaction was carried out for 58min. Finally, 26g 1,3-butadiene was added to the polymerization reactor for end-capping reaction for 27min until no free monomers were present. The adhesive solution was wet-coagulated and dried to obtain the functionalized random copolymer.

[0095] S2. Preparation of functionalized monomers: Nitrogen gas was purged three times in a 10L high-pressure reactor, 2800g of cyclohexane was added, and the temperature was raised to 88℃. Then, 180g of methylaluminoxane co-catalyst was added dropwise under uniform stirring at 670rpm. Stirring was continued for 28min under nitrogen protection. Subsequently, 70g of functionalized random copolymer, 80g of 1-octene, and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor in sequence. Ethylene was introduced, and the pressure was maintained at 15MPa for 5.6h. After the reaction was completed, the functionalized monomer (number average molecular weight Mn of 3700) was obtained by separation, devolatilization, and drying.

[0096] (II) Preparation of Functionalized Nitrile Rubber: 3500g of deionized water, 50g of sodium dodecylbenzene sulfonate soap, 1.4g of sodium formaldehyde sulfoxylate, 0.5g of EDTA-iron sodium salt, 360g of acrylonitrile monomer, and 17g of tert-dodecyl mercaptan were added to a 10L stirred pressure vessel. After evacuation, the mixture was purged with nitrogen three times. Then, 0.4g of sodium dithionite scavenger and 610g of 1,3-butadiene monomer were added. When the temperature of the polymerization vessel dropped to 9℃, 2.1g of dicumyl peroxide initiator was added to start the polymerization reaction. When the polymerization conversion rate reached 38%, 30g of functionalized monomer was added to continue the reaction. When the conversion rate reached 88.0%, 4.3g of sodium thiram termite was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to obtain functionalized nitrile rubber (gel content of 1.42%).

[0097] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfield Use: First, 200g of functionalized nitrile-butadiene rubber was dissolved in a chlorobenzene solution to prepare a 4.7% (by weight) rubber solution. Then, the solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 28 minutes. Then, under nitrogen protection, 0.43g of a toluene solution containing Grubbs II catalyst (10% by weight) was added. The hydrogen pressure in the reactor was increased to 15MPa, and the temperature was raised to 126℃. After reacting for 12 hours, the system was cooled, condensed, and vacuum dried to obtain cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfield use. Sampling and Analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0098] Example 4

[0099] This embodiment provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0100] (I) Preparation of functionalized monomers:

[0101] S1. Preparation of functionalized random copolymers: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas three times. Then, 3000g of cyclohexane, 1000g of diethylene glycol monovinyl ether, 800g of hexyl methacrylate, 5.0g of THF, and 276mmol of n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 70℃ and the reaction was carried out for 60min. Finally, 30g of 1,3-butadiene was added to the polymerization reactor for end-capping reaction for 30min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the functionalized random copolymer.

[0102] S2. Preparation of functionalized monomers: Nitrogen gas was purged three times in a 10L high-pressure reactor, 3000g of cyclohexane was added, and the temperature was raised to 90℃. Then, 200g of methylaluminoxane co-catalyst was added dropwise under uniform stirring at 700rpm. Stirring was continued for 30min under nitrogen protection. Subsequently, 80g of functionalized random copolymer, 100g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor in sequence. Ethylene was introduced and the pressure was maintained at 16MPa for 6.0h. After the reaction was completed, the functionalized monomer (number average molecular weight Mn of 4000) was obtained by separation, devolatilization and drying.

[0103] (II) Preparation of Functionalized Nitrile Rubber: 4000g of deionized water, 50g of sodium dodecylbenzene sulfonate soap, 1.5g of sodium formaldehyde sulfoxylate, 0.5g of EDTA-iron sodium salt, 380g of acrylonitrile monomer, and 20g of tert-dodecyl mercaptan were added to a 10L stirred pressure vessel. After evacuation, the mixture was purged with nitrogen three times. Then, 0.5g of sodium dithionite scavenger and 580g of 1,3-butadiene monomer were added. When the temperature of the polymerization vessel dropped to 11℃, 2.5g of dicumyl peroxide initiator was added to start the polymerization reaction. When the polymerization conversion rate reached 40%, 40g of functionalized monomer was added to continue the reaction. When the conversion rate reached 90%, 5.0g of sodium thiram termite was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to obtain functionalized nitrile rubber (gel content of 1.39%).

[0104] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfield Use: First, 200g of functionalized nitrile-butadiene rubber was dissolved in a chlorobenzene solution to prepare a 5.0% (by weight) rubber solution. Then, the solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 30 minutes. Then, under nitrogen protection, 0.5g of a toluene solution containing Grubbs II catalyst (12% by weight) was added. The hydrogen pressure in the reactor was increased to 16MPa, and the temperature was raised to 130℃. After reacting for 13 hours, the system was cooled, condensed, and vacuum dried to obtain cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfield use. Sampling and Analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0105] Comparative Example 1

[0106] This comparative example provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0107] (I) Preparation of functionalized monomers:

[0108] S1. Preparation of functionalized random copolymer: Other conditions are the same as in Example 1, except that methyl methacrylate is added instead of hexyl methacrylate during the preparation of the functionalized random copolymer. The amount added is 700g. That is, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas three times. 2000g cyclohexane, 1000g diethylene glycol monovinyl ether, 700g methyl methacrylate, 1.0g THF, and 260mmol n-butyllithium are added to the polymerization reactor in sequence. The temperature is raised to 60°C and the reaction is carried out for 50min. Finally, 10g 1,3-butadiene is added to the polymerization reactor for end-capping reaction for 20min until no free monomers are present. The glue solution is wet coagulated and dried to obtain functionalized random copolymer a.

[0109] S2. Preparation of functionalized monomers: Other conditions were the same as in Example 1, except that functionalized random copolymer a was added during the preparation of the functionalized monomers. The amount added was 40g. Specifically, nitrogen was purged three times in a 10L high-pressure reactor, 2000g of cyclohexane was added, the temperature was raised to 80°C, and 150g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 600rpm. Stirring was continued for 20min under nitrogen protection. Then, 40g of functionalized random copolymer a, 50g of 1-octene, and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added sequentially to the high-pressure reactor. Ethylene was introduced, and the pressure was maintained at 13MPa for 5.0h. After the reaction was completed, functionalized monomer a (number average molecular weight Mn of 2900) was obtained by separation, devolatilization, and drying.

[0110] (II) Preparation of Functionalized Nitrile Rubber: Other conditions are the same as in Example 1, except that functionalized monomer a is not added during the preparation of functionalized nitrile rubber. The amount added is 10g, that is: 2000g of deionized water, 40g of sodium dodecylbenzene sulfonate soap, 1.3g of sodium formaldehyde sulfoxylate, 0.2g of EDTA-iron sodium salt, 300g of acrylonitrile monomer, and 10g of tert-dodecyl mercaptan are added to a 10L stirred pressure vessel. After evacuation, the mixture is purged with nitrogen three times, and then added... 0.1g of sodium dithionite (an oxygen scavenger) and 690g of 1,3-butadiene monomer were added. When the temperature of the polymerization reactor dropped to 4℃, 1.0g of dicumyl hydroperoxide (an initiator) was added to start the polymerization reaction. When the polymerization conversion rate reached 35%, 10g of functionalized monomer a was added, and the reaction continued. When the conversion rate reached 85.0%, 3.0g of sodium thiram (a terminator) was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to prepare functionalized nitrile rubber a (with a gel content of 2.13%).

[0111] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfields: Other conditions were the same as in Example 1, except that functionalized nitrile-butadiene rubber a was added during the preparation process. The amount added was 200g. Specifically: First, 200g of functionalized nitrile-butadiene rubber a was dissolved in a chlorobenzene solution to prepare a 3% (by weight) rubber solution. Then, the solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 20 minutes. Then, under nitrogen protection, 0.10g of a toluene solution containing Grubbs II catalyst (6% by weight) was added. The hydrogen pressure in the reactor was increased to 13MPa, and the temperature was raised to 110℃. After reacting for 10 hours, the system was cooled, condensed, and vacuum dried to obtain the cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfields. Sampling and Analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0112] Comparative Example 2

[0113] This comparative example provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0114] (I) Preparation of functionalized monomers:

[0115] S1. Preparation of functionalized random copolymer: Other conditions are the same as in Example 2, except that diethylene glycol monovinyl ether is not added during the preparation of the functionalized random copolymer. That is, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas three times. 2400g of cyclohexane, 720g of hexyl methacrylate, 2.5g of THF, and 265mmol of n-butyllithium are added to the polymerization reactor in sequence. The temperature is raised to 63°C and the reaction is carried out for 52min. Finally, 16g of 1,3-butadiene is added to the polymerization reactor for end-capping reaction for 22min until no free monomers are present. The adhesive solution is wet-coagulated and dried to obtain functionalized random copolymer b.

[0116] S2. Preparation of functionalized monomers: Other conditions were the same as in Example 2, except that functionalized random copolymer b was added during the preparation of the functionalized monomers. The amount added was 50g. Specifically, nitrogen was purged three times in a 10L high-pressure reactor, 2300g of cyclohexane was added, the temperature was raised to 83°C, and 160g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 620rpm. Stirring was continued for 23min under nitrogen protection. Then, 50g of functionalized random copolymer b, 60g of 1-octene, and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added sequentially to the high-pressure reactor. Ethylene was introduced, and the pressure was maintained at 14MPa for 5.3h. After the reaction was completed, functionalized monomer b (number average molecular weight Mn of 2100) was obtained by separation, devolatilization, and drying.

[0117] (II) Preparation of Functionalized Nitrile Rubber: Other conditions are the same as in Example 2, except that functionalized monomer b is added during the preparation of functionalized nitrile rubber. The amount added is 20g, namely: 2600g deionized water, 42g sodium dodecylbenzenesulfonate soap, 1.4g sodium formaldehyde sulfoxylate, 0.3g EDTA-iron sodium salt, 330g acrylonitrile monomer, and 12g tert-dodecyl mercaptan are added to a 10L stirred pressure vessel. After evacuation, the mixture is purged with nitrogen three times, and then 0g of functionalized nitrile rubber is added. 0.3g of sodium dithionite (oxygen scavenger) and 650g of 1,3-butadiene monomer were added. When the temperature of the polymerization reactor dropped to 8°C, 1.5g of dicumyl hydroperoxide (initiator) was added to start the polymerization reaction. When the polymerization conversion rate reached 37%, 20g of functionalized monomer b was added, and the reaction continued. When the conversion rate reached 87.0%, 4.0g of sodium thiram (terminant) was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to prepare functionalized nitrile rubber b (gel content of 1.93%).

[0118] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfields: Other conditions were the same as in Example 2, except that functionalized nitrile-butadiene rubber b was added during the preparation process. The amount added was 200g. Specifically: First, 200g of functionalized nitrile-butadiene rubber b was dissolved in a chlorobenzene solution to prepare a 3.5% (by weight) rubber solution. Then, the solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 23 minutes. Then, under nitrogen protection, 0.31g of a toluene solution containing Grubbs II catalyst (9% by weight) was added. The hydrogen pressure in the reactor was increased to 14MPa, and the temperature was raised to 120℃. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain the cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfields. Sampling and Analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0119] Comparative Example 3

[0120] This comparative example provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0121] (I) Preparation of functionalized monomers: Other conditions are the same as in Example 3, except that no functionalized random copolymer is added during the preparation of functionalized monomers. Instead, 70g of diethylene glycol monovinyl ether is added. Specifically, nitrogen is purged three times in a 10L high-pressure reactor, 2800g of cyclohexane is added, the temperature is raised to 88°C, and 180g of methylaluminoxane co-catalyst is added dropwise under uniform stirring at 670rpm. Stirring is continued for 28min under nitrogen protection. Then, 70g of diethylene glycol monovinyl ether, 80g of 1-octene, and 10g of trans-phenyl bromide (di(triphenylphosphine))nickel main catalyst are added sequentially to the high-pressure reactor. Ethylene is introduced, and the pressure is maintained at 15MPa for 5.6h. After the reaction is completed, functionalized monomer c (number average molecular weight Mn is 2600) is obtained by separation, devolatilization, and drying.

[0122] (II) Preparation of Functionalized Nitrile Rubber: Other conditions are the same as in Example 3, except that functionalized monomer C is added during the preparation of functionalized nitrile rubber. The amount added is 30g, namely: 3500g deionized water, 50g sodium dodecylbenzenesulfonate soap, 1.4g sodium formaldehyde sulfoxylate, 0.5g EDTA-iron sodium salt, 360g acrylonitrile monomer, and 17g tert-dodecyl mercaptan are added to a 10L stirred pressure vessel. After evacuation, the mixture is purged with nitrogen three times, and then 0g of sodium formaldehyde sulfoxylate is added. 4g of sodium dithionite (an oxygen scavenger) and 610g of 1,3-butadiene monomer were added. When the temperature of the polymerization reactor dropped to 9°C, 2.1g of dicumyl hydroperoxide (an initiator) was added to start the polymerization reaction. When the polymerization conversion rate reached 38%, 30g of functionalized monomer C was added, and the reaction continued. When the conversion rate reached 88.0%, 4.3g of sodium thiram (a terminator) was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to prepare functionalized nitrile rubber C (with a gel content of 1.79%).

[0123] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfields: Other conditions were the same as in Example 3, except that 200g of functionalized nitrile-butadiene rubber (C) was added during the preparation process. Specifically, 200g of C was first dissolved in a chlorobenzene solution to prepare a 4.7% (by weight) solution. This solution was then added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. After purging the reactor with hydrogen gas for 28 minutes, 0.43g of a toluene solution containing Grubbs II catalyst (10% by weight) was added under nitrogen protection. The hydrogen pressure in the reactor was increased to 15MPa, and the temperature was raised to 126℃. After reacting for 12 hours, the system was cooled, condensed, and vacuum dried to obtain the cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfields. Sampling and Analysis: Standard samples were prepared, and their performance is shown in Table 1.

[0124] Comparative Example 4

[0125] This comparative example provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0126] (I) Preparation of functionalized monomers: Other conditions are the same as in Example 4, except that no functionalized random copolymer is added during the preparation of functionalized monomers. Instead, 80g of hexyl methacrylate is added. Specifically, nitrogen is purged three times in a 10L high-pressure reactor, 3000g of cyclohexane is added, the temperature is raised to 90°C, and 200g of methylaluminoxane co-catalyst is added dropwise under uniform stirring at 700rpm. Stirring is continued for 30min under nitrogen protection. Then, 80g of functionalized random copolymer d, 100g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst are added to the high-pressure reactor in sequence. Ethylene is introduced and the pressure is maintained at 16MPa for 6.0h. After the reaction is completed, functionalized monomer d (number average molecular weight Mn is 2700) is obtained by separation, devolatilization and drying.

[0127] (II) Preparation of Functionalized Nitrile Rubber: Other conditions are the same as in Example 4, except that functionalized monomer d is added during the preparation of functionalized nitrile rubber. The amount added is 40g, that is: 4000g of deionized water, 50g of sodium dodecylbenzenesulfonate soap, 1.5g of sodium formaldehyde sulfoxylate, 0.5g of EDTA-iron sodium salt, 380g of acrylonitrile monomer, and 20g of tert-dodecyl mercaptan are added to a 10L stirred pressure vessel. After vacuuming, the mixture is purged with nitrogen three times, and then added... 0.5g of sodium dithionite (oxygen scavenger) and 580g of 1,3-butadiene monomer were added. When the temperature of the polymerization reactor dropped to 11℃, 2.5g of dicumyl hydroperoxide (initiator) was added to start the polymerization reaction. When the polymerization conversion rate reached 40%, 40g of functionalized monomer d was added and the reaction continued. When the conversion rate reached 90%, 5.0g of sodium thiram (terminant) was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to prepare functionalized nitrile rubber d (gel content of 1.89%).

[0128] (III) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfields: Other conditions were the same as in Example 4, except that 200g of functionalized nitrile-butadiene rubber (d) was added during the preparation process. Specifically, 200g of functionalized nitrile-butadiene rubber (d) was first dissolved in a chlorobenzene solution to prepare a 5.0% (by weight) rubber solution. This solution was then added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. After purging the reactor with hydrogen gas for 30 minutes, 0.5g of a toluene solution containing Grubbs II catalyst (12% by weight) was added under nitrogen protection. The hydrogen pressure in the reactor was increased to 16MPa, and the temperature was raised to 130℃. After reacting for 13 hours, the system was cooled, condensed, and vacuum dried to obtain the cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfields. Sampling and Analysis: Standard samples were prepared, and their performance is shown in Table 1.

[0129] Comparative Example 5

[0130] This comparative example provides a method for preparing cold-resistant and oil-resistant hydrogenated nitrile butadiene rubber for oilfield use, which includes:

[0131] (I) Preparation of Functionalized Nitrile Rubber: Other conditions are the same as in Example 4, except that no functionalized monomer is added during the preparation of the functionalized nitrile rubber. Instead, 40g of hexyl methacrylate is added, namely: 4000g of deionized water, 50g of sodium dodecylbenzenesulfonate soap, 1.5g of sodium formaldehyde sulfoxylate, 0.5g of EDTA-iron sodium salt, 380g of acrylonitrile monomer, and 20g of tert-dodecyl mercaptan are added to a 10L stirred pressure vessel. After evacuation, nitrogen is used to replace the three... Next, 0.5g of sodium dithionite, an oxygen scavenger, and 580g of 1,3-butadiene monomer were added. When the temperature of the polymerization reactor dropped to 11℃, 2.5g of dicumyl hydroperoxide, an initiator, was added to start the polymerization reaction. When the polymerization conversion rate reached 40%, 40g of hexyl methacrylate was added to continue the reaction. When the conversion rate reached 90%, 5.0g of sodium thiram, a terminator, was added to terminate the polymerization. The mixture was stirred, discharged, coagulated, washed, and dried to prepare functionalized nitrile rubber e (gel content of 6.84%).

[0132] (II) Preparation of Cold-Resistant and Oil-Resistant Hydrogenated Nitrile-Butadiene Rubber for Oilfields: Other conditions were the same as in Example 4, except that 200g of functionalized nitrile-butadiene rubber e was added during the preparation process. Specifically, 200g of functionalized nitrile-butadiene rubber e was first dissolved in a chlorobenzene solution to prepare a 5.0% (by weight) rubber solution. This solution was then added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. After purging the reactor with hydrogen gas for 30 minutes, 0.5g of a toluene solution containing Grubbs II catalyst (12% by weight) was added under nitrogen protection. The hydrogen pressure in the reactor was increased to 16MPa, and the temperature was raised to 130℃. After reacting for 13 hours, the system was cooled, condensed, and vacuum dried to obtain the cold-resistant and oil-resistant hydrogenated nitrile-butadiene rubber for oilfields. Sampling and Analysis: Standard samples were prepared, and their performance is shown in Table 1.

[0133] Table 1

[0134] As shown in Table 1, the cold-resistant and oil-resistant hydrogenated nitrile rubber for oil fields of the present invention has a high degree of hydrogenation, a glass transition temperature Tg < -44℃, and a volume change rate < +9% under the condition of 150℃ × 42h in No. 1 standard oil, exhibiting excellent cold resistance and good oil resistance. The products after further low-temperature plasticizing and compounding can be used for oil well operations under extremely cold conditions of -52℃.

Claims

1. A functionalized monomer, wherein, The functionalized monomer has the structure shown in Formula I: In Formula I, R1 is a C4-C8 alkyl group, and R2 is a C6-C12 straight-chain alkyl group; B is a 1,3-butadiene segment with a cap; L, m, and n represent the number of repeating units, where L≥1, n≥1, and m≥1, and L, m, and n are positive integers.

2. The functionalized monomer according to claim 1, wherein, The number-average molecular weight of the functionalized monomer is 3000-4000.

3. A hydrogenated nitrile butadiene rubber raw material composition, wherein, Includes the first component and the second component; The first component includes acrylonitrile and butadiene monomer; The second component includes the functionalized monomer as described in claim 1 or 2.

4. The hydrogenated nitrile butadiene rubber raw material composition according to claim 3, wherein, It includes the first component, the second component, and the third component; The first component includes the acrylonitrile and 1,3-butadiene; The second component includes the functionalized monomer; The third component includes a terminator.

5. The hydrogenated nitrile butadiene rubber raw material composition according to claim 4, wherein, The first component also includes deionized water, emulsifier, activator, molecular weight regulator, oxygen scavenger and first initiator.

6. The hydrogenated nitrile butadiene rubber raw material composition according to claim 5, wherein, The weight ratio of the deionized water, the emulsifier, the activator, the acrylonitrile, the molecular weight regulator, the oxygen scavenger, 1,3-butadiene, the functionalized monomer, and the terminator is 200–400: 2.0–6.0: 0.1–0.3: 30–38: 0.5–3.0: 0.01–0.05: 58–69: 1.0–4.0: 0.3–0.

5.

7. The hydrogenated nitrile butadiene rubber raw material composition according to claim 5, wherein, The emulsifier is selected from one or a combination of two or more of alkyl sulfate emulsifiers, alkyl sulfonate emulsifiers, and aryl sulfonate emulsifiers.

8. The hydrogenated nitrile butadiene rubber raw material composition according to claim 5, wherein, The first initiator is selected from one or more of cumene hydroperoxide, dicumene hydroperoxide, isopropyl tert-butyl peroxide, and isopropyl n-butyl peroxide.

9. The hydrogenated nitrile butadiene rubber raw material composition according to claim 5, wherein, The activator is selected from one or a combination of two or more of the following: sodium formaldehyde sulfoxylate, ferrous sulfate, sodium EDTA, and sodium ferric EDTA.

10. The hydrogenated nitrile butadiene rubber raw material composition according to claim 5, wherein, The oxygen scavenger is selected from one or more combinations of sodium dithionite, dimethyl ketoxime, isoascorbic acid, carbazide, and N-isopropylhydroxylamine.

11. The hydrogenated nitrile butadiene rubber raw material composition according to claim 5, wherein, The terminating agent is selected from one or more combinations of hydroxylamine sulfate, diethylhydroxylamine, 2,5-pentanebutylquinone, sodium dimethyl dithiocarbamate, sodium nitrite, actinol reagent, and p-aminoazobenzene.

12. A method for preparing hydrogenated nitrile butadiene rubber, wherein, Hydrogenated nitrile butadiene rubber is prepared using the raw material composition according to any one of claims 3 to 11; the preparation method includes the following steps: The first component is mixed to carry out the first polymerization reaction in the first stage. When the acrylonitrile conversion rate reaches 35% to 40%, the second component is added to the system to carry out the first polymerization reaction in the second stage. When the acrylonitrile conversion rate reaches 85% to 90%, the polymerization is terminated to obtain functionalized nitrile rubber. The functionalized nitrile rubber is dissolved in an organic solvent to form a solution, and the solution is subjected to a hydrogenation reaction under the action of a catalyst to obtain the hydrogenated nitrile rubber.

13. The method for preparing hydrogenated nitrile butadiene rubber according to claim 12, wherein, The preparation method includes the following steps: The first component is mixed to carry out the first polymerization reaction in the first stage. When the acrylonitrile conversion rate reaches 35% to 40%, the second component is added to the system to carry out the first polymerization reaction in the second stage. When the acrylonitrile conversion rate reaches 85% to 90%, the third component is added to the system to terminate the polymerization, thereby obtaining functionalized nitrile rubber. The functionalized nitrile rubber is dissolved in an organic solvent to form a solution, and the solution is subjected to a hydrogenation reaction under the action of a catalyst to obtain the hydrogenated nitrile rubber.

14. The method for preparing hydrogenated nitrile butadiene rubber according to claim 12, wherein, The reaction temperature of the first polymerization reaction is 4–11 °C.

15. The method for preparing hydrogenated nitrile butadiene rubber according to claim 12, wherein, The hydrogenation reaction is carried out at a pressure of 13–16 MPa, a temperature of 110–130 °C, and a time of 10–13 h.

16. The method for preparing hydrogenated nitrile butadiene rubber according to claim 12, wherein, The functionalized monomer in the second component is prepared by the following steps: Diethylene glycol monovinyl ether, a first solvent, carbon chain methacrylate, a structure modifier, and a second initiator are mixed to carry out a second polymerization reaction. Then, 1,3-butadiene is added to the system to carry out an end-capping reaction. The polymerization is terminated when no free monomers are present, resulting in a functionalized random copolymer. The functionalized random copolymer, α-olefin, ethylene, main catalyst, co-catalyst, and second solvent are mixed to carry out a third polymerization reaction to obtain the functionalized monomer.

17. The method for preparing hydrogenated nitrile butadiene rubber according to claim 16, wherein, The weight ratio of the diethylene glycol monovinyl ether, the first solvent, the carbon chain methacrylate, the structure modifier, and 1,3-butadiene is 100:200-300:70-80:0.1-0.5:1.0-3.0; The weight ratio of the second solvent, the co-catalyst, the functionalized random copolymer, the α-olefin, and the main catalyst is 200–300:15–20:4–8:5–10:

1.

18. The method for preparing hydrogenated nitrile butadiene rubber according to claim 16, wherein, The carbon chain methacrylate is selected from one or more of butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, and octyl methacrylate.

19. The method for preparing hydrogenated nitrile butadiene rubber according to claim 16, wherein, The α-olefin is selected from one or more combinations of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene.

20. The method for preparing hydrogenated nitrile butadiene rubber according to claim 16, wherein, The main catalyst is selected from one or more of (1-naphthyl)[8-(diphenylphosphino)quinoline]nickel chloride, trans-phenyl bromide (di(triphenylphosphine))nickel, and 2,5-dicarboxypyrrole dibromide nickel.

21. The method for preparing hydrogenated nitrile butadiene rubber according to claim 16, wherein, The second initiator has the general structural formula RLi, wherein R is selected from one or more combinations of saturated aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups of C1-20.

Images