A cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field and a preparation method thereof

Abstract

The application discloses a cold-resistant and compression-resistant hydrogenated butyl nitrile rubber for oil fields and a preparation method thereof, and the preparation method comprises the following steps: (1) preparation of a functionalized macromolecular long-branch linking branching agent, and (2) preparation of the cold-resistant and compression-resistant hydrogenated butyl nitrile rubber for oil fields; the functionalized macromolecular long-branch linking branching agent has the following structure: wherein IR is an isoprene homopolymer segment with a wide ethylene group distribution; R is a straight-chain alkyl group with 6-12 carbon atoms; B is a capped 1,3-butadiene; n is a repeating unit number, and n is a positive integer greater than or equal to 1; the number average molecular weight (Mn) of the functionalized macromolecular long-branch linking branching agent is 6000-8000, and the molecular weight distribution (Mw / Mn) is 7.26-8.35. The preparation method of the cold-resistant and compression-resistant hydrogenated butyl nitrile rubber for oil fields has the characteristics of green environmental protection, efficient modification effect, low modifier consumption, easy availability of raw materials on the market and suitability for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of rubber technology, specifically relating to a cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields modified with a functionalized macromolecular long-branched linker and its preparation method. Background Technology

[0002] Hydrogenated nitrile butadiene rubber (HNBR) is prepared by selectively hydrogenating the carbon-carbon double bonds in nitrile butadiene rubber. Therefore, HNBR not only retains the oil resistance, corrosion resistance and elasticity of NBR, but also exhibits superior aging resistance and high temperature resistance. Furthermore, its mechanical properties such as tensile strength, elongation at break, abrasion resistance and hardness are improved. It is widely used in oil exploration equipment such as pump pistons, rotary hoses, valve seals, and drill pipe covers.

[0003] While hydrogenation of the carbon-carbon double bonds endows HNBR with excellent properties, it also introduces a serious drawback: the main chain of hydrogenated nitrile butadiene rubber (NBR) is a highly ordered polyethylene structure, which readily forms a crystalline structure, leading to an increase in temperature (Tg). Consequently, HNBR products exhibit poor cold resistance. Since most of my country's oil drilling operations are concentrated in the western and northeastern regions, where minimum temperatures can reach around -50°C, oil drilling equipment faces extremely demanding cold resistance requirements for rubber sealing materials.

[0004] In the existing technology, there are many patent documents reporting methods for preparing low-temperature resistant hydrogenated nitrile butadiene rubber. For example:

[0005] CN 106349410 B discloses a special hydrogenated nitrile butadiene rubber with compression cold resistance and its preparation method. The rubber backbone contains epoxy groups, some of which are also attached to ester side groups. The ester side groups are generated by a ring-opening reaction between C6-C24 acid anhydrides and the epoxy groups. The preparation method includes introducing epoxy groups into the rubber molecular backbone, and then reacting some of the epoxy groups with acid anhydrides under the action of a catalyst to introduce ester groups, thereby obtaining a special hydrogenated nitrile butadiene rubber containing epoxy groups and ester groups. CN 105294939B discloses a low-temperature grade hydrogenated nitrile butadiene rubber raw rubber, which is a copolymer of butadiene, acrylonitrile, and dibutyl transbutenedioate, with a number-average molecular weight of 1.05–3.25 × 10⁻⁶. 5 The weight-average molecular weight is 3.02–9.32 × 10⁻⁶. 5The polydispersity index is 2.0–2.7; the degree of hydrogenation of the low-temperature grade hydrogenated nitrile butadiene rubber raw rubber is above 90%, and the glass transition temperature is -38℃ to -42℃. CN 112592461 B discloses a modified hydrogenated nitrile butadiene rubber material with low-temperature resistance and high damping characteristics, its preparation method, and its application. The modified hydrogenated nitrile butadiene rubber material is prepared using HNBR / PNB block copolymer as raw material; the HNBR / PNB block copolymer is obtained by modifying NBR or HNBR through olefin metathesis reaction using norbornene monomer as a modifier. CN 115594898A discloses a low-temperature resistant hydrogenated nitrile butadiene rubber compound and its internal mixing preparation method. The method mainly involves blending and internal mixing hydrogenated nitrile butadiene raw rubber, plasticizer, and hardness modifier to obtain a hydrogenated nitrile butadiene rubber compound with a Shore A hardness of 67±5, tensile strength ≥14MPa, elongation at break ≥180%, compression set ≤35%, and a cold resistance coefficient at 45℃ ≥0.16, exhibiting cold resistance. CN 105754164A discloses a low-temperature resistant rubber material. Although this material shows improved cold resistance, the addition of the plasticizer dioctyl phthalate (DOP) reduces the material's mechanical properties and oil resistance. Furthermore, DOP is not environmentally friendly and is prone to leaching. Zhang Dongheng et al. disclosed that by blending ethylene propylene rubber (EPDM) with HNBR, the cold resistance of HNBR was improved. When the EPDM content was 15%, the Tg decreased by 3°C. However, with further increasing the EPDM content, the Tg of the blended rubber no longer decreased (Synthetic Rubber Industry, 2002, 25(1)). ).

[0006] While the cold resistance of hydrogenated nitrile butadiene rubber can be improved to some extent by adding small molecule modifiers, copolymerization, and blending, these methods still have limitations. Their preparation methods are complex, difficult to implement, require large amounts of additives, are costly, and have limited modification effects. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a method for preparing cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfield use, with a compression set ≤22% and a glass transition temperature (Tg) <-64℃, meeting the requirements for use in the range of -64℃ to -67℃. This invention first uses allyl ethylene glycol and long-chain α-olefins to prepare functionalized macromolecular long-chain monomers under the action of a nickel-based complexing catalyst. Second, using anionic polymerization, the reactive monomers are prepared from isoprene and the functionalized macromolecular long-chain monomers through temperature-switching polymerization to produce a functionalized macromolecular long-branched grafting agent with a broad vinyl distribution and free radical reactivity. Finally, the functionalized macromolecular long-branched grafting agent is grafted onto the main chain of hydrogenated NBR to prepare the cold-resistant and compression-resistant hydrogenated NBR for oilfield use. This method not only solves the problem of easy crystallization in hydrogenated nitrile butadiene rubber (NBR), but also improves its viscoelasticity, resulting in excellent low-temperature resistance and deformation resistance. It achieves a balance between these two properties, making it highly suitable for oil well operations at temperatures as low as -64°C.

[0008] Unless otherwise specified, the term "parts" in this invention refers to parts by mass, "%" refers to percentage by mass, and "ratio" refers to mass ratio.

[0009] To achieve the above objectives, the present invention provides a method for preparing cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields, the method comprising the following steps:

[0010] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0011] Inert gas was introduced into the reactor for purging, solvent was added, the temperature was raised, and alkylaluminoxane co-catalyst was added under stirring. Stirring continued under inert gas protection. Then, allyl ethylene glycol, long-chain α-olefin, and nickel-based complexing catalyst were added to the reactor. Ethylene was introduced at this time, and the reaction was carried out. After the reaction was completed, the product was separated by centrifugation and dried to obtain functionalized macromolecular long-chain monomers.

[0012] b. In the polymerization reactor, argon gas is introduced to purge the system. Solvent, isoprene, first structure modifier, and initiator 1 are added to the polymerization reactor in sequence. The reaction is a temperature-switching polymerization, in which the temperature is gradually increased from 50°C to 70°C within 60-70 minutes to form IR segments with a wide vinyl distribution. Then, the functionalized macromolecular long-chain monomer is mixed with the solution and stirred until completely dissolved. Then, it is added to the polymerization reactor with the second structure modifier to react. Finally, 1,3-butadiene is added to the polymerization reactor for end-capping. The reaction continues until no free monomers are present. The solution is wet-coagulated and dried to obtain the functionalized macromolecular long-branched branching agent.

[0013] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0014] The preparation of hydrogenated nitrile butadiene rubber (HNBR) involves dissolving nitrile butadiene rubber in a chlorobenzene solution to prepare a rubber solution. The rubber solution is then added to a reaction vessel, and an inert gas is introduced to remove air from the reaction vessel. After removing the inert gas from the reaction vessel with hydrogen, a xylene solution containing Grubbs I catalyst is added under nitrogen protection. The mixture is then pressurized, heated, and reacted. The system is then cooled, condensed, and dried to obtain HNBR rubber.

[0015] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields: HNBR rubber is dissolved in chlorobenzene solution to prepare a rubber solution. The rubber solution is then added to a reaction vessel, and an inert gas is introduced for purging. Functionalized macromolecular long-branched linking agent is then added to the reaction vessel, stirred and mixed, heated, and a mixture of initiator 2 and chlorobenzene is added. The reaction proceeds, followed by flocculation, washing, and drying to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields.

[0016] The functionalized macromolecular long-branched linker has the following structure:

[0017]

[0018] Wherein, IR is a homopolymer segment of isoprene with a broad vinyl distribution; R is a straight-chain alkyl group of C6 to C12; B is a terminal 1,3-butadiene; n is the number of repeating units, and n is a positive integer ≥ 1; the number average molecular weight (Mn) of the functionalized macromolecular long-branched linker is 6000 to 8000, and the molecular weight distribution (Mw / Mn) is 7.26 to 8.35.

[0019] The long-chain α-olefin described in this invention is a C6-C12 straight-chain olefin, which can be selected from one of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene, with 1-octene being preferred.

[0020] The nickel-based complexing catalyst of the present invention is selected from one of (1-naphthyl)[8-(diphenylphosphino)quinoline]nickel, trans-phenylbromo(di(triphenylphosphine))nickel and 2,5-dicarboxypyrrole dibromide, preferably trans-phenylbromo(di(triphenylphosphine))nickel.

[0021] The alkylaluminoxane cocatalyst described in this invention is selected from one of methylaluminoxane (MAO) and ethylaluminoxane (EAO), with methylaluminoxane being preferred.

[0022] The initiator 1 described in this invention is a hydrocarbon-based monolithium compound, namely RLi, wherein R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic group, or a complex group containing 1 to 20 carbon atoms. This hydrocarbon-based monolithium compound is selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthenelithium, cyclohexyllithium, and dodecyllithium, preferably n-butyllithium. The amount of organolithium added is determined by the molecular weight of the designed polymer.

[0023] The initiator 2 described in this invention is an organic peroxide selected from one of diacetyl peroxide, diisobutyryl peroxide, cumene hydroperoxide, diisobutyryl peroxide (DCP), and benzoyl peroxide (BPO), preferably BPO, and its addition amount is 0.05 to 0.1 parts based on 100 parts by weight of HNBR rubber.

[0024] The nitrile rubber of this invention is copolymerized from 1,3-butadiene and acrylonitrile via emulsion polymerization. The acrylonitrile content of the nitrile rubber is 20 wt% to 42 wt%, preferably 22 wt% to 35 wt%.

[0025] The structure modifier described in this invention is a polar organic compound that produces a solvation effect in the polymerization system, enabling it to adjust the reactivity ratio of styrene and butadiene, thus allowing them to copolymerize randomly. This type of polar organic compound is selected from one of diethylene glycol dimethyl ether (2G), tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, diethylene glycol dimethyl ether (DME), and triethylamine, preferably tetrahydrofuran (THF).

[0026] The solvent or solution described in this invention may be selected from one of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene, and xylene, with cyclohexane being preferred.

[0027] In step (1)a of the present invention, the mass ratio of the solvent, alkylaluminoxane co-catalyst, allyl ethylene glycol, long-chain α-olefin, and nickel-based complex catalyst is 200-300:10-20:5-10:10-20:1.

[0028] In step (1)a of the present invention, the temperature is raised to 80-90°C; the stirring speed is 700-800 rpm; and the stirring time is 20-30 min.

[0029] In step (1)a of the present invention, the reaction pressure is 10-15 MPa and the time is 2.0-3.0 hr.

[0030] In step (1)b of the present invention, the mass ratio of the solvent, isoprene, primary structure modifier, functionalized macromolecular long-chain monomer, solution, secondary structure modifier, and 1,3-butadiene is 200-400:100:0.2-0.5:5-10:100-200:0.05-0.3:2-4.

[0031] In step (1)b of the present invention, the time for stirring and dissolving after mixing is 60-70 min.

[0032] In step (1)b of the present invention, the reaction time in the polymerization reactor is 60-70 min.

[0033] In step (1)b of the present invention, the reaction time for the end capping is 20 to 30 minutes.

[0034] In step (2)a of the present invention, the mass ratio of the nitrile rubber and the Grubbs I catalyst is 100:0.02-0.1.

[0035] In step (2)a of the present invention, the mass fraction of nitrile rubber in the adhesive solution is 3% to 6%.

[0036] In step (2)a of the present invention, the mass concentration of GrubbsⅠ catalyst in the xylene solution of the GrubbsⅠ catalyst is 5% to 10%.

[0037] In step (2)a of the present invention, the pressure is increased to 11-14 MPa; the temperature is increased to 100-120°C; and the reaction time is 9-11 hours.

[0038] In step (2)a of the present invention, the degree of hydrogenation of the HNBR rubber is less than 90%.

[0039] In step (2)b of the present invention, the mass ratio of the HNBR rubber, the functionalized macromolecular long-branched linker, and the chlorobenzene is 100:3-5:100-200.

[0040] In step (2)b of the present invention, the mass fraction of HNBR rubber in the adhesive solution is 6% to 9%.

[0041] In step (2)b of the present invention, the reaction temperature is 70-80°C and the time is 10.0-12.0hr.

[0042] In step (2)b of the present invention, the grafting rate of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 2.7% to 3.9%.

[0043] The polymerization reactions described in this invention are carried out in an oxygen-free, anhydrous, and inert gas environment. The inert gas is nitrogen or a gas of a group 0 element in the periodic table, excluding radon, with nitrogen being preferred.

[0044] The reaction vessel described in this invention can be a loop reactor or a batch reactor, preferably a batch reactor.

[0045] In step (2)a of this invention, pressurization 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. This invention does not impose any special limitations on this.

[0046] The present invention also provides a cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields obtained by the above preparation method.

[0047] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0048] (1) The functionalized macromolecular long-branched linker prepared by the present invention firstly uses allyl ethylene glycol and long-chain α-olefin to prepare functionalized macromolecular long-chain monomers under the action of nickel-based complexing catalysts; then, using anionic polymerization method, functionalized macromolecular long-branched copolymers with free radical reactivity and containing isoprene homopolymer segments (IR), long branches, ether groups and hydroxyl groups are prepared through temperature-switched process; so that they can be grafted onto hydrogenated nitrile butadiene rubber, forming a branched structure containing widely distributed unsaturated double bonds, long branches, hydroxyl groups and ether groups on the main chain structure of hydrogenated nitrile butadiene rubber. This structure is very effective in destroying the crystallinity of HNBR and improving viscoelasticity, and achieves a good "synergistic effect" in achieving a balance between low temperature resistance and deformation resistance. It can prepare oilfield cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber with a glass transition temperature Tg < -64℃ and a compression set ≤ 22%.

[0049] (2) The cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber prepared by the present invention, under the condition of ensuring a certain degree of hydrogenation, makes full use of the "accumulation effect" of macromolecules, the "group effect" of hydroxyl and ether groups, and the "structural effect" of wide distribution and long chain branched structure. It can greatly reduce the glass transition temperature (Tg) of HNBR with a low addition amount, while also significantly improving the compression set resistance of HNBR. It is suitable for oil well operations under low temperature conditions of -64℃.

[0050] (3) The preparation method of the oilfield cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber of the present invention has the characteristics of being green and environmentally friendly, having a high efficiency of modification effect, low amount of modifier, readily available raw materials, and being suitable for industrial production. Detailed Implementation

[0051] The following examples and comparative examples illustrate the inventive effects of the present invention, but the scope of protection of the present invention is not limited to these examples and comparative examples. The raw materials used in the examples are all industrial grade, purified before use, and have no other special requirements. The "parts" mentioned in the examples and comparative examples refer to parts by weight.

[0052] (1) Source of raw materials:

[0053]

[0054] (2) Analysis and testing methods:

[0055] Grafting rate determination: Approximately 4g of sample was pipetted from a three-necked flask into a weighing bottle. After weighing, 2-3 drops of hydroquinone solution were added, and the sample was dried to constant weight. The sample was then placed in a Soxhlet extractor and extracted with toluene in a 90°C water bath for 24 hours, followed by drying to constant weight. The monomer grafting rate was calculated using the following formula:

[0056]

[0057] Where: m0—total mass of adhesive (g); m—mass of the sample taken after reaction (g); m m —Total mass of monomers in the reactants (g); m HNBR —The mass of hydrogenated nitrile rubber in the sample (g); m1—The mass of the sample after extraction (g).

[0058] 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 .

[0059] Determination of HNBR hydrogenation degree: using nuclear magnetic resonance hydrogen spectroscopy (NMR spectroscopy). 1 The degree of hydrogenation of hydrogenated nitrile butadiene rubber (NMR) is calculated using the following main methods: 1. The product is completely dissolved in deuterated chloroform to prepare a 1H NMR sample; 2. The 1H NMR spectrum is measured and analyzed: The degree of hydrogenation of hydrogenated nitrile butadiene rubber is determined by 1H NMR spectroscopy and calculated using 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 hydrocarbons: 1.25 ppm, characteristic proton peak of cyano-linked groups: 2.5 ppm. The formula for calculating the degree of hydrogenation is as follows:

[0060] Degree of hydrogenation (HD%) = 1 - Degree of unsaturation (U)

[0061] 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.

[0062] Compression set: The method specified in standard GB / T 7759.1-2015 shall be followed.

[0063] Example 1

[0064] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0065] Preparation of functionalized macromolecular long-chain monomers: First, inert gas was purged three times in a 10L high-pressure reactor, and 2000g of cyclohexane was added. After heating to 80℃, 100g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 700rpm. Stirring was continued for 20min under inert gas protection. Then, 50g of allyl ethylene glycol, 100g of 1-octene, and 10g of trans--phenylbromophenyl(di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced at this time, and the pressure was maintained at 10MPa for 2.0hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying, and processing.

[0066] Preparation of functionalized macromolecular long-branched linker: In a jacketed 10L stainless steel polymerization reactor, the system was purged three times with argon gas. 1000g cyclohexane, 500g isoprene, and 1.0g THF were added sequentially to the reactor. The temperature was raised to 50℃, and 89mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 50℃ to 70℃ within 60 minutes, forming IR segments with a broad vinyl distribution. Then, 25g of functionalized macromolecular long-chain monomer and 500g cyclohexane were mixed and stirred for 60 minutes to dissolve, followed by the addition of 0.3g THF to the polymerization reactor and reacted for 60 minutes. Finally, 10g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 20 minutes until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker (Mn = 6000, Mw / Mn = 7.26).

[0067] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0068] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2907 was dissolved in chlorobenzene solution to prepare a 3% (w / w) rubber solution. Then, the rubber 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, 0.02g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 11MPa, and the temperature was raised to 100℃. After reacting for 9.0 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 84.1%).

[0069] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced three times for purging. Next, 6.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 70℃, a mixture of 0.10g BPO and 200g chlorobenzene was added. After reacting for 10.0 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use (grafting rate 2.7%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0070] Example 2

[0071] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0072] Preparation of functionalized macromolecular long-chain monomers: First, inert gas was purged three times in a 10L high-pressure reactor, and 2200g of cyclohexane was added. After heating to 82℃, 110g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a stirring speed of 720rpm. Stirring was continued for 22min under inert gas protection. Then, 60g of allyl ethylene glycol, 120g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine)) nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced at this time, and the pressure was maintained at 11MPa for 2.1hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying and processing.

[0073] Preparation of functionalized macromolecular long-branched linker: In a jacketed 10L stainless steel polymerization reactor, the system was purged three times with argon gas. 1200g of cyclohexane, 500g of isoprene, and 1.3g of THF were added sequentially to the reactor. The temperature was raised to 50℃, and 85mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 50℃ to 70℃ within 62 minutes, forming IR segments with a broad vinyl distribution. Then, 26g of functionalized macromolecular long-chain monomer and 600g of cyclohexane were mixed and stirred for 62 minutes to dissolve, followed by the addition of 0.6g of THF to the polymerization reactor and reacted for 62 minutes. Finally, 12g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 22 minutes until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker (Mn = 6400, Mw / Mn = 7.41).

[0074] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0075] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2907 was dissolved in chlorobenzene solution to prepare a 3% (w / w) rubber solution. Then, the rubber 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 32 minutes. Then, under nitrogen protection, 0.03g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 12MPa, and the temperature was raised to 105℃. After reacting for 9.5 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 85.7%).

[0076] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6.7% (by mass) rubber solution. Then, the solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced three times for purging. Next, 7.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 72℃, a mixture of 0.12g BPO and 260g chlorobenzene was added. After reacting for 10.5 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use (grafting rate 3.0%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0077] Example 3

[0078] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0079] Preparation of functionalized macromolecular long-chain monomers: First, inert gas was purged four times in a 10L high-pressure reactor, and 2400g of cyclohexane was added. After heating to 84℃, 130g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a stirring speed of 740rpm. Stirring was continued for 24min under inert gas protection. Then, 70g of allyl ethylene glycol, 140g of 1-octene and 10g of trans--phenylbromophenyl(di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced at this time, and the pressure was maintained at 12MPa for 2.3hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying and processing.

[0080] Preparation of functionalized macromolecular long-branched linker: In a jacketed 10L stainless steel polymerization reactor, the system was purged four times with argon gas. 1400g of cyclohexane, 500g of isoprene, and 1.7g of THF were added sequentially to the reactor. The temperature was raised to 50℃, and 78mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 50℃ to 70℃ within 64 minutes, forming IR segments with a broad vinyl distribution. Then, 27g of functionalized macromolecular long-chain monomer and 700g of cyclohexane were mixed and stirred for 64 minutes to dissolve, followed by the addition of 0.9g of THF to the polymerization reactor and reacted for 64 minutes. Finally, 14g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 24 minutes until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker (Mn = 6900, Mw / Mn = 7.82).

[0081] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0082] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2907 was dissolved in chlorobenzene solution to prepare a 4% (w / w) rubber solution. Then, the rubber 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 34 min. Then, under nitrogen protection, 0.05g of xylene solution containing Grubbs I catalyst (w / w, 7% (w / w)) was added. The hydrogen pressure in the reactor was increased to 12MPa, and the temperature was raised to 110℃. After reacting for 10 h, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 86.2%).

[0083] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 7.6% (by mass) rubber solution. Then, the solution was added to a 10L jacketed stainless steel reactor, and nitrogen was introduced to purge the mixture four times. Next, 8.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 74℃, a mixture of 0.14g BPO and 290g chlorobenzene was added. After reacting for 11.0 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use (grafting rate 3.2%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0084] Example 4

[0085] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0086] Preparation of functionalized macromolecular long-chain monomers: First, inert gas was purged four times in a 10L high-pressure reactor, and 2600g of cyclohexane was added. After heating to 86℃, 150g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 760rpm. Stirring was continued for 26min under inert gas protection. Then, 80g of allyl ethylene glycol, 160g of 1-octene, and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced at this time, and the pressure was maintained at 13MPa for 2.5hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying, and processing.

[0087] Preparation of functionalized macromolecular long-branched linker: In a jacketed 10L stainless steel polymerization reactor, the system was purged four times with argon gas. 1600g of cyclohexane, 500g of isoprene, and 1.9g of THF were added sequentially to the reactor. The temperature was raised to 50℃, and 74mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 50℃ to 70℃ within 66min, forming IR segments with a broad vinyl distribution. Then, 28g of functionalized macromolecular long-chain monomer and 800g of cyclohexane were mixed and stirred for 64min, followed by the addition of 1.2g of THF to the polymerization reactor and reacted for 66min. Finally, 16g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 26min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker (Mn = 7300, Mw / Mn = 7.96).

[0088] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0089] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2907 was dissolved in chlorobenzene solution to prepare a 4.5% (w / w) rubber solution. Then, the rubber 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 36 min. Then, under nitrogen protection, 0.07g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 12MPa, and the temperature was raised to 113℃. After reacting for 10 h, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 87.1%).

[0090] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a rubber solution with a mass fraction of 8.1%. Then, the rubber solution was added to a 10L stainless steel reactor with a jacket, and nitrogen gas was introduced to purge the solution four times. Next, 9.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 76℃, a mixture of 0.16g of BPO and 320g of chlorobenzene was added. After reacting for 11.3 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use (grafting rate 3.5%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0091] Example 5

[0092] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0093] Preparation of functionalized macromolecular long-chain monomers: First, inert gas was purged five times in a 10L high-pressure reactor, and 2800g of cyclohexane was added. After heating to 88℃, 170g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 780rpm. Stirring was continued for 28min under inert gas protection. Then, 90g of allyl ethylene glycol, 180g of 1-octene, and 10g of trans-phenyl bromide (di(triphenylphosphine)) nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced at this time, and the pressure was maintained at 14MPa for 2.7hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying, and processing.

[0094] Preparation of functionalized macromolecular long-branched linker: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas five times. 1800g of cyclohexane, 500g of isoprene, and 2.2g of THF were added sequentially to the polymerization reactor. The temperature was raised to 50℃, and 69mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 50℃ to 70℃ within 68min, forming IR segments with a broad vinyl distribution. Then, 29g of functionalized macromolecular long-chain monomer and 900g of cyclohexane were mixed and stirred for 68min, followed by the addition of 1.3g of THF to the polymerization reactor and reacted for 68min. Finally, 18g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 28min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker (Mn = 7700, Mw / Mn = 8.16).

[0095] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0096] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2907 was dissolved in chlorobenzene solution to prepare a 4.5% (w / w) rubber solution. Then, the rubber 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 36 min. Then, under nitrogen protection, 0.07g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 12MPa, and the temperature was raised to 113℃. After reacting for 10 h, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 87.1%).

[0097] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a rubber solution with a mass fraction of 8.1%. Then, the rubber solution was added to a 10L stainless steel reactor with a jacket, and nitrogen gas was introduced to purge five times. Next, 9.5g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred, mixed, and heated. When the reactor temperature reached 78℃, a mixture of 0.18g of BPO and 380g of chlorobenzene was added. After reacting for 11.8 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use (grafting rate 3.8%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0098] Example 6

[0099] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0100] Preparation of functionalized macromolecular long-chain monomers: First, inert gas was purged five times in a 10L high-pressure reactor, and 3000g of cyclohexane was added. After heating to 90℃, 200g of ethylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 800rpm. Stirring was continued for 30min under inert gas protection. Then, 100g of allyl ethylene glycol, 200g of 1-hexene, and 10g of 2,5-dicarboxypyrrole nickel dibromide main catalyst were added to the high-pressure reactor. Ethylene was introduced at this time, and the pressure was maintained at 15MPa for 3.0hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying, and processing.

[0101] Preparation of functionalized macromolecular long-branched linker: In a jacketed 10L stainless steel polymerization reactor, the system was purged five times with argon gas. 2000g of cyclohexane, 500g of isoprene, and 2.5g of THF were added sequentially to the reactor. The temperature was raised to 50℃, and 65mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 50℃ to 70℃ over 70 minutes, forming IR segments with a broad vinyl distribution. Then, 50g of functionalized macromolecular long-chain monomer and 1000g of cyclohexane were mixed and stirred for 70 minutes to dissolve. This mixture was then added to the polymerization reactor along with 1.4g of THF and reacted for another 70 minutes. Finally, 20g of 1,3-butadiene was added to the reactor for end-capping, and the reaction continued for 30 minutes until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker (Mn = 8000, Mw / Mn = 8.35).

[0102] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0103] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2907 was dissolved in chlorobenzene solution to prepare a 6.0% (w / w) rubber solution. Then, the rubber 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 40 minutes. Then, under nitrogen protection, 0.1g of xylene solution containing Grubbs I catalyst (w / w, 10% (w / w)) 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 HNBR rubber (hydrogenation degree HD = 89.4%).

[0104] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 9.0% (by mass) rubber solution. Then, the solution was added to a 10L jacketed stainless steel reactor, and nitrogen was introduced to purge five times. Next, 10g of a functionalized macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 80℃, a mixture of 0.20g BPO and 400g chlorobenzene was added. After reacting for 12.0 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use (grafting rate 3.9%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0105] Comparative Example 1

[0106] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0107] Preparation of functionalized macromolecular long-chain monomer a: Other conditions are the same as in Example 1, except that allyl ethylene glycol is not added during the preparation of the functionalized macromolecular long-chain monomer. Instead, allyl alcohol is added in an amount of 50g. Specifically: First, inert gas is purged three times in a 10L high-pressure reactor, then 2000g of cyclohexane is added. After heating to 80°C, 100g of methylaluminoxane co-catalyst is gradually added dropwise under uniform stirring at a speed of 700rpm. Stirring is continued for 20min under inert gas protection. Then, 50g of allyl alcohol, 100g of 1-octene, and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst are added to the high-pressure reactor. Ethylene is then introduced, and the pressure is maintained at 10MPa for 2.0hr. After the reaction is completed, the functionalized macromolecular long-chain monomer a is obtained by centrifugation, drying, and processing.

[0108] Preparation of functionalized macromolecular long-chain branching agent: Other conditions are the same as in Example 1, except that no functionalized macromolecular long-chain monomer is added during the preparation of the functionalized macromolecular long-chain branching agent. Instead, functionalized macromolecular long-chain monomer a is added in an amount of 25g. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system is purged three times with argon gas. 1000g of cyclohexane, 500g of isoprene, and 1.0g of THF are added to the polymerization reactor sequentially. The temperature is raised to 50°C, and 89mmol of n-butyllithium is added to initiate the reaction. The reaction temperature is gradually increased from 50°C to 70°C within 60min to form IR segments with a broad vinyl distribution. Then, 25g of functionalized macromolecular long-chain monomer a and 500g of cyclohexane are mixed and stirred for 60min to dissolve. Then, 0.3g of THF is added to the polymerization reactor and reacted for 60min. Finally, 10g of THF is added to the polymerization reactor. 1,3-Butadiene was capped and reacted for 20 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain functionalized macromolecular long-branched linker a (Mn is 5800, Mw / Mn is 7.05).

[0109] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0110] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 1.

[0111] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfields: Other conditions are the same as in Example 1, except that no functionalized macromolecular long-branched grafting agent is added during the preparation of the cold-resistant and compression-resistant hydrogenated NBR for oilfields. Instead, functionalized macromolecular long-branched grafting agent a is added, with an addition amount of 6.0g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 6% by mass solution. Then, the solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced to purge the solution three times. Next, 6.0g of functionalized macromolecular long-branched grafting agent a is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 70°C, a mixture of 0.10g of BPO and 200g of chlorobenzene is added. After reacting for 10.0hr, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated NBR for oilfields (grafting rate 2.5%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0112] Comparative Example 2

[0113] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0114] Preparation of functionalized macromolecular long-chain monomers: Other conditions were the same as in Example 2, except that 1-octene was not added during the preparation of functionalized macromolecular long-chain monomers, but 1-butene was added in an amount of 120g. Specifically: First, inert gas was purged three times in a 10L high-pressure reactor, then 2200g of cyclohexane was added. After heating to 82°C, 110g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 720rpm. Stirring was continued for 22min under inert gas protection. Then, 60g of allyl ethylene glycol, 120g of 1-butene, and 10g of trans-phenyl bromide (di(triphenylphosphine)) nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced at this time, and the pressure was maintained at 11MPa for 2.1hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying, and processing.

[0115] Preparation of functionalized macromolecular long-chain branching agent b: Other conditions are the same as in Example 2, except that no functionalized macromolecular long-chain monomer is added during the preparation of the functionalized macromolecular long-chain branching agent. Instead, functionalized macromolecular long-chain monomer b is added in an amount of 26g. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system is purged three times with argon gas. 1200g of cyclohexane, 500g of isoprene, and 1.3g of THF are added to the polymerization reactor sequentially. The temperature is raised to 50°C, and 85mmol of n-butyllithium is added to initiate the reaction. The reaction temperature gradually increases from 50°C to 70°C within 62min, forming IR segments with a broad vinyl distribution. Then, 26g of functionalized macromolecular long-chain monomer b and 600g of cyclohexane are mixed and stirred for 62min to dissolve. Then, 0.6g of THF is added to the polymerization reactor and reacted for 62min. Finally, 12g of functionalized macromolecular long-chain monomer b is added to the polymerization reactor. 1,3-Butadiene was end-capped and reacted for 22 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain functionalized macromolecular long-branched linker b (Mn is 5600, Mw / Mn is 5.82).

[0116] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0117] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 2.

[0118] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfields: Other conditions are the same as in Example 2, except that no functionalized macromolecular long-branched grafting agent is added during the preparation of NBR for oilfields. Instead, functionalized macromolecular long-branched grafting agent b is added, with an addition amount of 7.0g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 6.7% by mass solution. Then, the solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced to purge three times. Then, 7.0g of functionalized macromolecular long-branched grafting agent b is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 72°C, a mixture of 0.12g of BPO and 260g of chlorobenzene is added. After reacting for 10.5 hours, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated NBR for oilfields (grafting rate 3.0%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0119] Comparative Example 3

[0120] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0121] Other conditions are the same as in Example 3, except that no functionalized macromolecular long-chain monomers are added during the preparation of the functionalized macromolecular long-branched linker. Instead, 27g of the small molecule reactive monomer allyl ethylene glycol is added. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas four times. 1400g of cyclohexane, 500g of isoprene, and 1.7g of THF are added to the polymerization reactor sequentially. The temperature is raised to 50°C, and 78mmol of n-butyllithium is added to initiate the reaction. The reaction temperature gradually increases from 50°C to 70°C within 64 minutes, forming IR segments with a broad vinyl distribution. Then, 27g of allyl ethylene glycol and 700g of cyclohexane are mixed and stirred for 64 minutes to dissolve, and then 0.9g of THF is added to the polymerization reactor and reacted for 64 minutes. Finally, 14g of allyl ethylene glycol is added to the polymerization reactor. 1,3-Butadiene was end-capped and reacted for 24 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain functionalized macromolecular long-branched linker c (Mn is 4700, Mw / Mn is 5.32).

[0122] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0123] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 3.

[0124] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfields: Other conditions are the same as in Example 3, except that no functionalized macromolecular long-branched grafting agent is added during the preparation of NBR for oilfields. Instead, functionalized macromolecular long-branched grafting agent c is added, with an addition amount of 8.0g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 7.6% by mass solution. Then, the solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced to purge it four times. Then, 8.0g of functionalized macromolecular long-branched grafting agent c is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 74°C, a mixture of 0.14g of BPO and 290g of chlorobenzene is added. After reacting for 11.0hr, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated NBR for oilfields (grafting rate 2.9%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0125] Comparative Example 4

[0126] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0127] Preparation of functionalized macromolecular long-chain monomers: Same as in Example 4.

[0128] Preparation of functionalized macromolecular long-chain branching agents: Other conditions were the same as in Example 4, except that the amount of functionalized macromolecular long-chain monomer added during the preparation of the functionalized macromolecular long-chain branching agent was 10g. That is, in a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas four times, and 1600g of cyclohexane, 500g of isoprene, and 1.9g of THF were added to the polymerization reactor in sequence. The temperature was raised to 50°C, and 74mmol of n-butyllithium was added to start the reaction. The reaction temperature gradually increased from 50°C to 70°C within 66min, forming IR segments with a broad vinyl distribution. Then, 10g of functionalized macromolecular long-chain monomer and 800g of cyclohexane were mixed and stirred to dissolve for 64min, and then 1.2g of THF were added to the polymerization reactor and reacted for 66min. Finally, 16g of THF was added to the polymerization reactor. 1,3-Butadiene was end-capped and reacted for 26 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain functionalized macromolecular long-branched linker d (Mn is 5900, Mw / Mn is 7.21).

[0129] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0130] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 4.

[0131] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfields: Other conditions are the same as in Example 4, except that no functionalized macromolecular long-branched grafting agent is added during the preparation of the cold-resistant and compression-resistant hydrogenated NBR for oilfields. Instead, functionalized macromolecular long-branched grafting agent d is added, with an addition amount of 9.0g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.1%. Then, the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced to replace it 4 times. Then, 9.0g of functionalized macromolecular long-branched grafting agent is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 76°C, a mixture of 0.16g of BPO and 320g of chlorobenzene is added. After reacting for 11.3 hours, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated NBR for oilfields (grafting rate 2.6%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0132] Comparative Example 5

[0133] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0134] Preparation of functionalized macromolecular long-chain monomers: Same as in Example 5.

[0135] Preparation of functionalized macromolecular long-branched branching agents: Other conditions were the same as in Example 5, except that the IR segments were not subjected to temperature-switched polymerization during the preparation of the functionalized macromolecular long-branched branching agents, resulting in narrowly distributed IR segments. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas five times. 1800g of cyclohexane, 500g of isoprene, and 2.2g of THF were added sequentially to the polymerization reactor. The temperature was raised to 50°C, and 69 mmol of n-butyllithium was added. The reaction was carried out for 68 min to form narrowly distributed vinyl IR segments. Then, 29g of functionalized macromolecular long-chain monomer and 900g of cyclohexane were mixed and stirred for 68 min to dissolve, followed by the addition of 1.3g of THF to the polymerization reactor and a reaction for 68 min. Finally, 18g of… 1,3-Butadiene was capped and reacted for 28 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain functionalized macromolecular long-branched linker e (Mn is 7600, Mw / Mn is 4.12).

[0136] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0137] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 5.

[0138] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfields: Other conditions are the same as in Example 5, except that no functionalized macromolecular long-branched grafting agent is added during the preparation of the cold-resistant and compression-resistant hydrogenated NBR for oilfields. Instead, functionalized macromolecular long-branched grafting agent e is added, with an addition amount of 9.5g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.1%. Then, the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced to replace it 5 times. Then, 9.5g of functionalized macromolecular long-branched grafting agent e is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 78°C, a mixture of 0.18g of BPO and 380g of chlorobenzene is added. After reacting for 11.8 hours, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated NBR for oilfields (grafting rate 3.5%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0139] Comparative Example 6

[0140] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0141] Preparation of functionalized macromolecular long-chain monomers: Other conditions were the same as in Example 6, except that the amount of allyl ethylene glycol added during the preparation of functionalized macromolecular long-chain monomers was 30g. Specifically: First, inert gas was purged five times in a 10L high-pressure reactor, then 3000g of cyclohexane was added. After heating to 90°C, 200g of ethylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 800rpm. Stirring was continued for 30min under inert gas protection. Subsequently, 30g of allyl ethylene glycol, 200g of 1-hexene, and 10g of 2,5-dicarboxypyrrole nickel dibromide main catalyst were added to the high-pressure reactor. Ethylene was then introduced, and the pressure was maintained at 15MPa for 3.0hr. After the reaction was completed, the functionalized macromolecular long-chain monomers were obtained by centrifugation, drying, and processing.

[0142] Preparation of functionalized macromolecular long-chain branching agent: Other conditions are the same as in Example 6, except that no functionalized macromolecular long-chain monomer is added during the preparation of the functionalized macromolecular long-chain branching agent. Instead, functionalized macromolecular long-chain monomer c is added in an amount of 50g. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas 5 times. 2000g of cyclohexane, 500g of isoprene, and 2.5g of THF are added sequentially to the polymerization reactor. The temperature is raised to 50°C, and 65mmol of n-butyllithium is added to initiate the reaction. The reaction temperature is gradually increased from 50°C to 70°C within 70min, forming IR segments with a broad vinyl distribution. Then, 50g of functionalized macromolecular long-chain monomer c and 1000g of cyclohexane are mixed and stirred for 70min to dissolve, followed by the addition of 1.4g of... THF was added to the polymerization reactor and reacted for 70 min; finally, 20 g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 30 min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker f (Mn is 6600, Mw / Mn is 7.15).

[0143] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0144] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 6.

[0145] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields: Other conditions are the same as in Example 6, except that no functionalized macromolecular long-branched grafting agent is added during the preparation of the cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields. Instead, functionalized macromolecular long-branched grafting agent f is added, with an addition amount of 10g. That is: first, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 9.0% by mass solution. Then, the solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced to replace it 5 times. Then, 10g of functionalized macromolecular long-branched grafting agent f is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 80°C, a mixture of 0.20g of BPO and 400g of chlorobenzene is added. After reacting for 12.0hr, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields (grafting rate 2.4%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0146] Table 1. Properties of Cold-Resistant and Compression-Resistant Hydrogenated Nitrile Rubber for Oilfield Use

[0147]

[0148]

[0149] As shown in Table 1, the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields of the present invention has small compression set and low glass transition temperature, making it suitable for oil well operations under low-temperature conditions of -64℃.

[0150] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the present invention.

Claims

1. A method for preparing cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use, characterized in that, Includes the following steps: (1) Preparation of functionalized macromolecular long-branched linking agents: In an inert gas purging process, a solvent is added to a reaction vessel, the temperature is raised, and an alkylaluminoxane co-catalyst is added under stirring. Stirring continues under inert gas protection. Then, allyl ethylene glycol, a long-chain α-olefin, and a nickel-based complexing catalyst are added to the reaction vessel, and ethylene is introduced to initiate the reaction. After the reaction is complete, the mixture is centrifuged and dried to obtain a functionalized macromolecular long-chain monomer. The long-chain α-olefin is selected from one of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene. The mass ratio of the solvent, alkylaluminoxane co-catalyst, allyl ethylene glycol, long-chain α-olefin, and nickel-based complexing catalyst is 200~300:10~20:5~10:10~20:

1. b. In the polymerization reactor, argon gas is introduced to purge the system. Solvent, isoprene, first structure modifier, and initiator 1 are added sequentially to the polymerization reactor. The reaction is a temperature-switching polymerization, with the temperature gradually increasing from 50°C to 70°C over 60-70 minutes to form isoprene homopolymer segments with a wide vinyl distribution. Then, functionalized macromolecular long-chain monomers are mixed with the solution and stirred until completely dissolved. After complete dissolution, they are added to the polymerization reactor along with the second structure modifier. Finally, 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction continues until no free monomers are present. The solution is then wet-coagulated and dried to obtain a functionalized macromolecular long-branched linker. The mass ratio of the solvent, isoprene, first structure modifier, functionalized macromolecular long-chain monomer, solution, second structure modifier, and 1,3-butadiene is 200-400:100:0.2-0.5:5-10:100-200:0.05-0.3:2-4. (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields: Preparation of hydrogenated nitrile butadiene rubber (HNBR): Nitrile butadiene rubber is dissolved in chlorobenzene solution to prepare a rubber solution. The rubber solution is then added to a reaction vessel, and an inert gas is introduced to remove the air from the reaction vessel. After the inert gas in the reaction vessel is removed by hydrogen, a xylene solution of Grubbs I catalyst is added under nitrogen protection. The system is pressurized, heated, and reacted. The system is then cooled, condensed, and dried to obtain HNBR rubber. Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields: HNBR rubber is dissolved in chlorobenzene solution to prepare a rubber solution. The rubber solution is then added to a reaction vessel, and an inert gas is introduced for purging. Functionalized macromolecular long-branched linking agent is then added to the reaction vessel, stirred and mixed, heated, and a mixture of initiator 2 and chlorobenzene is added. The reaction proceeds, followed by flocculation, washing, and drying to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields. The functionalized macromolecular long-branched linker has a number-average molecular weight (Mn) of 6000-8000 and a molecular weight distribution (Mw / Mn) of 7.26-8.

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2. The preparation method according to claim 1, characterized in that, The nickel-based complexing catalyst is selected from one of (1-naphthyl)[8-(diphenylphosphino)quinoline]nickel chloride, trans-phenyl bromide (di(triphenylphosphine))nickel, and 2,5-dicarboxypyrrole nickel dibromide.

3. The preparation method according to claim 1, characterized in that, The alkylaluminoxane cocatalyst is selected from methylaluminoxane (MAO) and ethylaluminoxane (EAO).

4. The preparation method according to claim 1, characterized in that, The initiator 1 is selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium, and dodecyllithium.

5. The preparation method according to claim 1, characterized in that, The initiator 2 is selected from one of diacetyl peroxide, diisobutyryl peroxide, cumene hydroperoxide, diisobutyryl peroxide (DCP), and benzoyl peroxide (BPO), and its addition amount is 0.05 to 0.1 parts based on 100 parts by weight of HNBR rubber.

6. The preparation method according to claim 1, characterized in that, The nitrile rubber is copolymerized from 1,3-butadiene and acrylonitrile through emulsion polymerization, wherein the acrylonitrile content of the nitrile rubber is 20wt% to 42wt%.

7. The preparation method according to claim 1, characterized in that, The structure modifier is selected from one of diethylene glycol dimethyl ether 2G, tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, diethylene glycol dimethyl ether (DME), and triethylamine.

8. The preparation method according to claim 1, characterized in that, The solvent or solution is selected from one of cyclohexane, carbon disulfide CS2, nitrobenzene, petroleum ether, tetrachloroethane, toluene, and xylene.

9. The preparation method according to claim 1, characterized in that, In step (2)a, the mass ratio of the nitrile rubber to the Grubbs I catalyst is 100:0.02~0.

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10. The preparation method according to claim 1, characterized in that, In step (2)a, the degree of hydrogenation of the HNBR rubber is less than 90%.

11. The preparation method according to claim 1, characterized in that, In step (2)b, the mass ratio of HNBR rubber, functionalized macromolecular long-branched linker, and chlorobenzene is 100:3~5:100~200.

12. The preparation method according to claim 1, characterized in that, In step (2)b, the grafting rate of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 2.7% to 3.9%.

13. A cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields, prepared by the method according to any one of claims 1-12.

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