Cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field and preparation method thereof

Abstract

The application discloses 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; SBR is a styrene and 1,3-butadiene random block copolymer segment; 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 5000-7000, and the molecular weight distribution (Mw / Mn) is 6.14-7.86. 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] The application belongs to the technical field of rubber, and particularly relates to a functional macromolecular long-branching grafting agent modified cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields and a preparation method thereof. BACKGROUND

[0002] The hydrogenated nitrile rubber (abbreviated as HNBR) is prepared by selectively hydrogenating the carbon-carbon double bond in the nitrile rubber, so that the HNBR not only retains the oil resistance, corrosion resistance and elasticity of the NBR, but also exhibits superior aging resistance and high temperature resistance, and the mechanical properties such as tensile strength, elongation at break, wear resistance and hardness are improved, and is widely used in petroleum exploration equipment such as pump pistons, rotary hoses, valve sealing rings and drill pipe shrouds.

[0003] Although the hydrogenation of the carbon-carbon double bond endows the HNBR with very excellent properties, it also brings a serious defect problem to the HNBR material. The main chain of the hydrogenated nitrile rubber (abbreviated as NBR) is a highly ordered polyethylene structure, which is very easy to form a crystalline structure, and at the same time causes the increase of Tg, so that the low temperature resistance of the HNBR product is poor. Since most of the oil drilling businesses in China are concentrated in the western and northeastern regions, the minimum temperature in these regions can reach about -50℃, and the oil drilling equipment faces the application environment under low temperature conditions, and the low temperature resistance of the rubber sealing material is extremely high.

[0004] There are many patent literatures about the preparation method of low-temperature-resistant hydrogenated nitrile rubber in the prior art. For example:

[0005] CN 106349410 B discloses a compression-resistant and cold-resistant special hydrogenated nitrile rubber and a preparation method thereof, which contains epoxy groups on the rubber main chain, and part of the epoxy groups are further connected with ester side groups; the ester side groups are generated by ring-opening reaction of C6-C24 acid anhydride and the epoxy groups. The preparation method comprises introducing epoxy groups into the rubber molecular main chain, and then introducing ester groups by reacting part of the epoxy groups with acid anhydride under the action of a catalyst to obtain the special hydrogenated nitrile rubber containing epoxy groups and ester groups. CN 105294939 B discloses a low-temperature-grade hydrogenated nitrile rubber raw rubber, which is a copolymer of butadiene, acrylonitrile and dibutyl fumarate, and the number average molecular weight of the copolymer is 1.05-3.25 x 10 5 , and the weight average molecular weight is 3.02-9.32 x 10 5polydispersity coefficient is 2.0-2.7; the hydrogenation degree of the low-temperature grade hydrogenated butyl nitrile rubber raw rubber is above 90%, and the glass transition temperature is -38℃ to -42℃. CN 112592461 B discloses a modified hydrogenated butyl nitrile rubber material with low-temperature resistance and high damping characteristics, and a preparation method and application thereof. The modified hydrogenated butyl nitrile rubber material is prepared by using an HNBR / PNB block copolymer as a raw material; the HNBR / PNB block copolymer is obtained by modifying NBR or HNBR through olefin metathesis reaction with norbornene monomer as a modifier. CN 115594898 A discloses a low-temperature resistant hydrogenated butyl nitrile rubber compound and a banburying preparation method thereof, mainly blending, banburying hydrogenated butyl nitrile rubber, plasticizer and hardness regulator, finally obtaining a hydrogenated butyl nitrile rubber compound with low-temperature resistance, having a Shore A hardness of 67±5, a tensile strength of ≥14 MPa, an elongation at break of ≥180%, a compression set of ≤35%, and a 45℃ compression cold resistance coefficient of ≥0.16. CN 105754164 A discloses a low-temperature resistant rubber material, although the low-temperature resistance of the material is improved, the addition of plasticizer dioctyl phthalate (DOP) causes the mechanical properties and oil resistance of the material to decrease, and DOP is not environmentally friendly and is easy to precipitate. Zhang Dongheng et al. disclose that the low-temperature performance of HNBR is improved by blending ethylene-propylene rubber (EPDM) with HNBR, and when the EPDM addition amount is 15%, the Tg decreases by 3℃; but further increasing the EPDM amount, the Tg of the blended rubber does not decrease any more (Synthetic Rubber Industry, 2002, 25(1): )。

[0006] In the above prior art, although the low-temperature resistance of hydrogenated butyl nitrile rubber can be improved to some extent by adding small molecule modifiers, copolymerization and blending methods, these methods still have certain limitations, and the preparation methods have the problems of complex process, difficult actual operation, large addition amount, high cost, and unobvious modification effect. SUMMARY

[0007] In order to solve the problems in the prior art, the present application provides a preparation method of a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields with compression set < 26% and glass transition temperature Tg < -61℃, which can meet the use requirements in the range of -61℃ to -63℃. The application first uses an anionic polymerization method to prepare a functionalized macromolecular long branch linker with a wide ethylene group distribution and a free radical reaction activity by distributing synthesis of reaction monomers of isoprene, styrene, 1,3-butadiene and dihydromyrcenol; and then the functionalized macromolecular long branch linker is grafted to the main chain of the hydrogenated nitrile rubber to prepare the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields. The method not only solves the problem of easy crystallization of the hydrogenated nitrile rubber, but also improves the viscoelasticity of the hydrogenated nitrile rubber, so that the hydrogenated nitrile rubber shows very excellent low-temperature resistance and deformation resistance, and realizes the balance between the low-temperature resistance and the deformation resistance of the hydrogenated nitrile rubber. It is very suitable for oil well operation under low-temperature working conditions of -61℃.

[0008] Unless otherwise specified, the "parts" in the present application refer to mass parts, the "%" refers to mass percentage, and the "ratio" refers to mass ratio.

[0009] In order to achieve the above-mentioned purpose, the present application provides a preparation method of a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, which comprises the following steps:

[0010] (1) Preparation of a functionalized macromolecular long branch linker:

[0011] In the polymerization kettle, argon is introduced for replacement, and then the solvent, isoprene, the first structure regulator, and initiator 1 are sequentially added to the polymerization kettle for variable temperature polymerization, in which the temperature is gradually increased from 45℃ to 65℃ within 50-60 min to form an IR segment with a wide ethylene group distribution; then the temperature is increased to 70-80℃, and then 1,3-butadiene, styrene, and the second structure regulator are sequentially added to the polymerization kettle for reaction for 70-80 min to form an SBR random segment; then the functional monomer dihydromyrcenol and the third structure regulator are added to the polymerization kettle for reaction for 40-50 min; finally, 1,3-butadiene is added to the polymerization kettle for end capping for 20-30 min until no free monomer exists, and then the glue solution is subjected to wet coagulation and drying to obtain the functionalized macromolecular long branch linker;

[0012] (2) Preparation of a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0013] a Preparation of hydrogenated nitrile rubber (HNBR): the nitrile rubber is dissolved in chlorobenzene solution, configured into glue solution, then the glue solution is added into the reaction kettle, inert gas is introduced to replace the air in the reaction kettle, then the xylene solution of Grubbs I catalyst is added under the protection of nitrogen, pressurized, heated, reacted, the system is cooled, coagulated, dried, and HNBR rubber is obtained;

[0014] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field: the HNBR rubber is dissolved in chlorobenzene solution, configured into glue solution, then the glue solution is added into the reaction kettle, inert gas is introduced to replace the air in the reaction kettle, then the functionalized macromolecular long branch linking agent is added into the reaction kettle, stirred and mixed, heated, the mixed solution of initiator 2 and chlorobenzene is added, after reaction, flocculation, washing, drying, and the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field is obtained;

[0015] The functionalized macromolecular long branch linking agent has the following structure:

[0016]

[0017] Wherein, IR is an isoprene homopolymer segment with a wide ethylene group distribution; SBR is a random block copolymer segment of styrene and 1,3-butadiene; B is a capped 1,3-butadiene, n is the number of repeating units, 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 agent is 5000-7000, and the molecular weight distribution (Mw / Mn) is 6.14-7.86.

[0018] The initiator 1 in the application is a hydrocarbyl monolithium compound, that is, RLi, wherein R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of the above groups containing 1-20 carbon atoms. The hydrocarbyl monolithium compound is selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthyl lithium, cyclohexyllithium and dodecyl lithium, and preferably n-butyllithium. The amount of organic lithium added is determined by the molecular weight of the designed polymer.

[0019] The initiator 2 in the application is an organic peroxide selected from one of diacetyl peroxide, diisobutyryl peroxide, cumene hydroperoxide, dicumyl peroxide (DCP) and dibenzoyl peroxide, and preferably dicumyl peroxide (DCP). The amount of initiator 2 added is 0.05-0.3 parts, and preferably 0.1-0.2 parts, based on 100 parts of HNBR rubber.

[0020] The nitrile rubber in the application is copolymerized by emulsion polymerization of 1,3-butadiene and acrylonitrile. The acrylonitrile content of the nitrile rubber is 20wt%-42wt%, and preferably 22wt%-35wt%.

[0021] The structure regulator is a polar organic compound which produces a solvation effect in a polymerization system, can regulate the reactivity ratio of styrene and 1,3-butadiene, and makes the two randomly copolymerize.

[0022] The solvent can be selected from one of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene, xylene, preferably cyclohexane.

[0023] In step (1), the mass ratio of the solvent, isoprene, structure regulator, 1,3-butadiene, styrene, and second structure regulator in the formation of the SBR random segment is 200-300:100:0.2-0.5:30-40:20-30:0.5-1.0.

[0024] In the end-capping process, the mass ratio of the dihydromyrcenol, third structure regulator, and 1,3-butadiene is 10-20:0.1-0.5:2-4.

[0025] In step (2)a, the mass ratio of the nitrile rubber and Grubbs I catalyst is 100:0.02-0.1.

[0026] In step (2)a, the mass fraction of nitrile rubber in the glue solution is 3%-6%.

[0027] In step (2)a, the mass concentration of the Grubbs I catalyst in the xylene solution is 5%-10%.

[0028] In step (2)a, the pressure is 11-14 MPa, the temperature is 100-120℃, and the reaction time is 9-11 hr.

[0029] In step (2)a, the hydrogenation degree HD of the HNBR rubber is less than 90%.

[0030] In step (2)b, the mass ratio of the HNBR rubber, functionalized macromolecular long-chain branch linker, and chlorobenzene is 100:3-5:100-200.

[0031] In step (2)b, the mass fraction of HNBR rubber in the glue solution is 6%-9%.

[0032] In step (2)b of the present application, the reaction temperature is 70-80℃. The time is 10.0-12.0 hours.

[0033] In step (2)b of the present application, the grafting rate of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field is 2.3%-3.4%.

[0034] The polymerization reaction of the present application is carried out in an oxygen-free, water-free and inert gas environment. The inert gas is nitrogen or a gas of the element of group 0 in the periodic table except radon, preferably nitrogen.

[0035] The high-pressure reactor of the present application can be a loop reactor or a tank reactor, preferably a tank reactor.

[0036] In step (2)a of the present application, the pressurization is achieved by adding hydrogen. The amount of hydrogen added is well known to those skilled in the art, and the amount of hydrogen added conforms to the conventional addition range in the prior art, which is not particularly limited in the present application.

[0037] The present application also provides a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field prepared by the above preparation method.

[0038] Compared with the prior art, the present application has at least the following advantages and beneficial effects:

[0039] (1) The functionalized macromolecular long-branching grafting agent prepared by the present application utilizes an anionic polymerization method to prepare a macromolecular copolymer with free radical reaction activity, containing a wide ethylene group distribution isoprene homopolymer segment (IR), a styrene and 1,3-butadiene random block copolymer segment (SBR), and a long carbon chain hydroxyl group, which can be grafted onto hydrogenated nitrile rubber to form a branched structure containing a wide distribution of unsaturated double bonds, a random distribution of benzene rings and 1,3-butadiene, and a long carbon chain hydroxyl group on the main chain structure of the hydrogenated nitrile rubber. This structure has a very significant effect on destroying the crystallinity of HNBR and improving the viscoelasticity, achieving a good "synergistic effect" in balancing the low temperature resistance and deformation resistance, and being able to prepare a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field with a compression set of raw rubber ≤26% and a glass transition temperature Tg<-61℃.

[0040] (2) The cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field prepared by the present application fully utilizes the "accumulation effect", "group effect" and "structure effect" of the hydroxyl group, benzene ring and unsaturated double bond under the condition of ensuring a certain hydrogenation degree, which can greatly reduce the glass transition temperature (Tg) of HNBR while significantly improving the compression set resistance of HNBR with a low addition amount, and is suitable for oil well operation under low temperature conditions of-61℃.

[0041] (3) The method for preparing cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oil fields 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

[0042] 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.

[0043] (1) Source of raw materials:

[0044]

[0045] (2) Analysis and testing methods:

[0046] 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:

[0047]

[0048] 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).

[0049] 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 .

[0050] Determination of HNBR hydrogenation degree: using nuclear magnetic resonance hydrogen spectroscopy (NMR spectroscopy). 1The 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:

[0051] Degree of hydrogenation (HD%) = 1 - Degree of unsaturation (U)

[0052] 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.

[0053] Compression set: The method specified in standard GB / T 7759.1-2015 shall be followed.

[0054] Example 1

[0055] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0056] In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. Then, 1000g of cyclohexane, 500g of isoprene, and 1.0g of THF were added sequentially. The temperature was raised to 45°C, and 165mmol of n-butyllithium was added to initiate the reaction. The reaction temperature was gradually increased from 45°C to 65°C over 50 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 70°C, and 150g of 1,3-butadiene, 100g of styrene, and 2.5g of THF were added sequentially. The reaction was continued for 70 minutes, forming SBR random segments. Next, 50g of dihydromyrceneol and 0.5g of THF were added, and the reaction was continued for 40 minutes. Finally, 10g of... 1,3-Butadiene was end-capped and reacted for 20 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain a functionalized macromolecular long-branched linker (Mn = 5000, Mw / Mn = 6.14).

[0057] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0058] 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%).

[0059] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfields: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6% (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, 6.0g of a 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 of DCP and 200g of 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 oilfields (grafting rate 2.3%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0060] Example 2

[0061] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0062] In a jacketed 10L stainless steel polymerization reactor, the system was purged three times with argon gas. Then, 1100g of cyclohexane, 500g of isoprene, and 1.3g of THF were added sequentially. The temperature was raised to 45°C, and 156 mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 45°C to 65°C within 52 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 72°C, and 160g of 1,3-butadiene, 110g of styrene, and 3.0g of THF were added sequentially. The reaction was continued for 72 minutes, forming SBR random segments. Next, 60g of dihydromyrceneol and 1.0g of THF were added, and the reaction was continued for 42 minutes. Finally, 12g of... 1,3-Butadiene was used for end-capping, and the reaction was carried out for 22 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain a functionalized macromolecular long-branched linker (Mn = 5600, Mw / Mn = 6.53).

[0063] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0064] 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%).

[0065] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfields: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6.5% (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, 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 of DCP and 260g of 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 oilfields (grafting rate 2.5%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0066] Example 3

[0067] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0068] In a jacketed 10L stainless steel polymerization reactor, the system was purged four times with argon gas. Then, 1200g of cyclohexane, 500g of isoprene, and 1.8g of THF were added sequentially. The temperature was raised to 45°C, and 142 mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 45°C to 65°C within 54 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 74°C, and 170g of 1,3-butadiene, 120g of styrene, and 3.5g of THF were added sequentially. The reaction was continued for 74 minutes, forming SBR random segments. Next, 70g of dihydromyrceneol and 1.5g of THF were added, and the reaction was continued for 44 minutes. Finally, 14g of... 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 a functionalized macromolecular long-branched linker (Mn = 5900, Mw / Mn = 6.87).

[0069] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0070] 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%).

[0071] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfields: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 7.0% (w / w) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced to purge the solution 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 of DCP and 290g of chlorobenzene was added. After reacting for 11 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 oilfields (grafting rate 2.7%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0072] Example 4

[0073] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0074] In a jacketed 10L stainless steel polymerization reactor, the system was purged four times with argon gas. Then, 1300g of cyclohexane, 500g of isoprene, and 2.0g of THF were added sequentially. The temperature was raised to 45°C, and 134 mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 45°C to 65°C within 56 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 76°C, and 180g of 1,3-butadiene, 130g of styrene, and 4.0g of THF were added sequentially. The reaction was continued for 76 minutes, forming SBR random segments. Next, 80g of dihydromyrceneol and 2.0g of THF were added, and the reaction was continued for 46 minutes. Finally, 16g of... 1,3-Butadiene was used for end-capping, and the reaction was carried out for 26 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain a functionalized macromolecular long-branched linker (Mn = 6200, Mw / Mn = 7.12).

[0075] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0076] 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%).

[0077] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfields: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 7.5% (by mass) rubber solution. Then, the solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced four times for purging. 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 DCP 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 oilfields (grafting rate 3.0%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0078] Example 5

[0079] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0080] In a jacketed 10L stainless steel polymerization reactor, the system was purged five times with argon gas. Then, 1400g of cyclohexane, 500g of isoprene, and 2.3g of THF were added sequentially. The temperature was raised to 45°C, and 127 mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 45°C to 65°C within 58 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 78°C, and 190g of 1,3-butadiene, 140g of styrene, and 4.5g of THF were added sequentially. The reaction was continued for 78 minutes, forming SBR random segments. Next, 90g of dihydromyrceneol and 2.3g of THF were added, and the reaction was continued for 48 minutes. Finally, 18g of... 1,3-Butadiene was used for end-capping, and the reaction was carried out for 28 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain a functionalized macromolecular long-branched linker (Mn = 6700, Mw / Mn = 7.51).

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

[0082] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2907 was dissolved in chlorobenzene solution to prepare a 5.0% (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 38 min. Then, under nitrogen protection, 0.09g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 13MPa, and the temperature was raised to 117℃. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 88.3%).

[0083] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfields: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a rubber solution with a mass fraction of 8.0%. 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 DCP and 360g of chlorobenzene was added. After reacting for 11.6 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 oilfields (grafting rate 3.1%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0084] Example 6

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

[0086] In a 10L stainless steel polymerization reactor with a jacket, the system was purged five times with argon gas. Then, 1500g of cyclohexane, 500g of isoprene, and 2.5g of THF were added sequentially. The temperature was raised to 45°C, and 120mmol of n-butyllithium was added to initiate the reaction. The reaction temperature was gradually increased from 45°C to 65°C over 60 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 80°C, and 200g of 1,3-butadiene, 150g of styrene, and 5.0g of THF were added sequentially. The reaction was continued for 80 minutes, forming SBR random segments. Next, 100g of dihydromyrceneol and 2.5g of THF were added, and the reaction was continued for 50 minutes. Finally, 20g of... 1,3-Butadiene was end-capped and reacted for 30 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain a functionalized macromolecular long-branched linker (Mn = 7000, Mw / Mn = 7.86).

[0087] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0088] 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%).

[0089] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (HNBR) for oilfields: 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 stainless steel reactor with a jacket, and nitrogen was introduced to purge the mixture 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 0.2g of DCP and 400g of chlorobenzene was added. After reacting for 12 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 oilfields (grafting rate 3.4%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0090] Comparative Example 1

[0091] (1) Preparation of functionalized macromolecular long-branched linker: Same as in Example 1.

[0092] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0093] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 1.

[0094] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfields: Other conditions were the same as in Example 1, except that the amount of functionalized macromolecular long-branched grafting agent added was 4.0 g. Specifically: First, 200 g 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, 4.0 g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 70°C, a mixture of 0.10 g of DCP and 200 g of chlorobenzene was added. After reacting for 10.0 hours, the mixture was 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 2.0%). Sampling and analysis: Standard samples were prepared, and the tested performance is shown in Table 1.

[0095] Comparative Example 2

[0096] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0097] Other conditions were the same as in Example 2, except that the IR segments in the preparation of the functionalized macromolecular long-branched linker were not subjected to temperature-switched polymerization to generate narrowly distributed IR segments. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 1100g of cyclohexane, 500g of isoprene, and 1.3g of THF were added sequentially to the polymerization reactor. The temperature was raised to 45°C, and 156mmol of n-butyllithium was added to initiate the reaction. The reaction was carried out for 52 minutes to form narrowly distributed vinyl IR segments. Then, the temperature was raised to 72°C, and 160g of 1,3-butadiene, 110g of styrene, and 3.0g of THF were added sequentially to the polymerization reactor. The reaction was carried out for 72 minutes to form SBR random segments. Then, 60g of dihydromyrceneol and 1.0g of THF were added to the polymerization reactor, and the reaction was carried out for 42 minutes. Finally, 12g of [unspecified substance] was added to the polymerization reactor. 1,3-Butadiene was 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 a (Mn is 5600, Mw / Mn is 4.76).

[0098] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0099] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 2.

[0100] b. Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber 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 cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields. Instead, functionalized macromolecular long-branched grafting agent a is added, with an addition amount of 7.0g. That is: first, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 6.5% by mass solution. Then, the solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced to replace it three times. Then, 7.0g of functionalized macromolecular long-branched grafting agent a is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 72°C, a mixture of 0.12g of DCP and 260g of chlorobenzene is added. After reacting for 10.5hr, 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.

[0101] Comparative Example 3

[0102] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0103] Other conditions were the same as in Example 3, except that isoprene was not added during the preparation of the functionalized macromolecular long-branched linker. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas four times. 1200g of cyclohexane, 170g of 1,3-butadiene, 120g of styrene, and 3.5g of THF were added sequentially to the polymerization reactor. The temperature was raised to 74°C, and 142mmol of n-butyllithium was added to initiate a reaction for 74 minutes to form SBR random segments. Then, 70g of dihydromyrceneol and 1.5g of THF were added to the polymerization reactor, and the reaction was carried out for 44 minutes. Finally, 14g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 24 minutes until no free monomers were present. The solution was then wet-coagulated and dried to obtain the functionalized macromolecular long-branched linker b (Mn = 4800, Mw / Mn = 3.14).

[0104] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0105] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 3.

[0106] 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 cold-resistant and compression-resistant NBR for oilfields. Instead, functionalized macromolecular long-branched grafting agent b is added, with an addition amount of 8.0g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 7.0% 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. Next, 8.0g of functionalized macromolecular long-branched grafting agent b is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 74°C, a mixture of 0.14g of DCP and 290g of chlorobenzene is added. After reacting for 11 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 2.5%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0107] Comparative Example 4

[0108] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0109] Other conditions were the same as in Example 4, except that the amount of dihydromyrcenol added during the preparation of the functionalized macromolecular long-branched linker was 40g. Specifically: in a jacketed 10L stainless steel polymerization reactor, the system was purged four times with argon gas. Then, 1300g of cyclohexane, 500g of isoprene, and 2.0g of THF were added sequentially. The temperature was raised to 45°C, and 134 mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 45°C to 65°C within 56 minutes, forming IR segments with a broad vinyl distribution. Then, the temperature was raised to 76°C, and 180g of 1,3-butadiene, 130g of styrene, and 4.0g of THF were added sequentially. The reaction was continued for 76 minutes, forming SBR random segments. Next, 40g of dihydromyrcenol and 2.0g of THF were added to the polymerization reactor, and the reaction was continued for 46 minutes. Finally, 16g of dihydromyrcenol 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 c (Mn is 5700, Mw / Mn is 6.98).

[0110] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use:

[0111] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 4.

[0112] Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber 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 cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields. Instead, functionalized macromolecular long-branched grafting agent c is added, with an addition amount of 9.0g. That is: first, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 7.5% by mass solution. Then, the 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 c is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 76°C, a mixture of 0.16g of DCP 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 nitrile butadiene rubber for oilfields (grafting rate 2.8%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0113] Comparative Example 5

[0114] (1) Preparation of functionalized macromolecular long-branched linking agents:

[0115] Other conditions were the same as in Example 5, except that dihydromyrcene alcohol was not added during the preparation of the functionalized macromolecular long-branched linker; instead, 90g of allyl alcohol was added. Specifically, in a jacketed 10L stainless steel polymerization reactor, the system was purged five times with argon gas. Then, 1400g of cyclohexane, 500g of isoprene, and 2.3g of THF were added sequentially. The temperature was raised to 45°C, and 127mmol of n-butyllithium was added to initiate the reaction. The reaction temperature gradually increased from 45°C to 65°C within 58 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 78°C, and 190g of 1,3-butadiene, 140g of styrene, and 4.5g of THF were added sequentially. The reaction was allowed to proceed for 78 minutes, forming SBR random segments. Finally, 90g of allyl alcohol and 2.3g of THF were added to the polymerization reactor. THF reaction for 48 min; then 18 g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 28 min until no free monomers were present. The solution was then wet-coagulated and dried to obtain functionalized macromolecular long-branched linker d (Mn is 6500, Mw / Mn is 7.42).

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

[0117] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 5.

[0118] b. Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber 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 cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields. Instead, functionalized macromolecular long-branched grafting agent d is added, with an addition amount of 9.5g. That is: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.0%. 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 d is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 78°C, a mixture of 0.18g of DCP and 360g of chlorobenzene is added. After reacting for 11.6 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 nitrile butadiene rubber for oilfields (grafting rate 2.9%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0119] Comparative Example 6

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

[0121] Other conditions were the same as in Example 6, except that 1,3-butadiene was not added during the preparation of the functionalized macromolecular long-branched linker, thus preventing the formation of SBR random segments and instead generating PS homopolymer segments. Specifically, in a jacketed 10L stainless steel polymerization reactor, the system was purged five times with argon gas. Then, 1500g of cyclohexane, 500g of isoprene, and 2.5g of THF were added sequentially to the reactor. The temperature was raised to 45°C, and 120mmol of n-butyllithium was added to initiate the reaction. The reaction temperature was gradually increased from 45°C to 65°C within 60 minutes, forming IR segments with a broad vinyl distribution. The temperature was then raised to 80°C, and 150g of styrene and 5.0g of THF were added sequentially. The reaction was continued for 80 minutes to form PS homopolymer segments. Finally, 100g of dihydromyrcene alcohol and 2.5g of... THF reaction for 50 min; then add 20 g of 1,3-butadiene to the polymerization reactor for end-capping and react for 30 min until no free monomers are present. The solution is then wet-coagulated and dried to obtain functionalized macromolecular long-branched linker e (Mn is 58000, Mw / Mn is 5.63).

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

[0123] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 6.

[0124] b. 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 cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields. Instead, functionalized macromolecular long-branched grafting agent e 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 e is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 80°C, a mixture of 0.2g of DCP and 400g of chlorobenzene is added. After reacting for 12 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 nitrile butadiene rubber for oilfields (grafting rate 3.2%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0125] Table 1. Properties of Cold-Resistant and Compression-Resistant Hydrogenated Nitrile Rubber for Oilfield Use

[0126]

[0127]

[0128] 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 -61℃.

[0129] 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 the polymerization reactor, argon gas is introduced for purging. Solvent, isoprene, primary structure modifier, and initiator 1 are added sequentially. The reaction is a temperature-switched polymerization, with the temperature gradually increased from 45°C to 65°C over 50-60 minutes to form broad vinyl distribution IR segments. Then, the temperature is raised to 70-80°C, and 1,3-butadiene, styrene, and secondary structure modifier are added sequentially. The reaction is continued for 70-80 minutes to form SBR random segments. Finally, more... The functional monomer dihydromyrcenol and the third structure modifier are added and reacted for 40-50 minutes. Finally, 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction is continued for 20-30 minutes until no free monomers are present. The solution is then wet-coagulated and dried to obtain a functionalized macromolecular long-branched linker. In the end-capping process, the mass ratio of dihydromyrcenol, the third structure modifier, and 1,3-butadiene is 10-20:0.1-0.5:2-4. (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use: 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. b. 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. Then, the rubber solution is added to a reaction vessel and replaced with an inert gas. Then, functionalized macromolecular long-branched linking agent is added to the reaction vessel, stirred and mixed, heated, and a mixture of initiator 2 and chlorobenzene is added. After reaction, flocculation, washing, and drying are performed to obtain cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfields. In step (2) b, the mass ratio of HNBR rubber, functionalized macromolecular long-branched linking agent, and chlorobenzene is 100:3~5:100~200. The functionalized macromolecular long-branched linker has a number-average molecular weight (Mn) of 5000-7000 and a molecular weight distribution (Mw / Mn) of 6.14-7.

86.

2. 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.

3. 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, and its addition amount is 0.05 to 0.3 parts based on 100 parts of HNBR rubber.

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

5. 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.

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

7. The preparation method according to claim 1, characterized in that, In step (1), during the formation of the SBR random segments, the mass ratio of the solvent, isoprene, primary structure modifier, 1,3-butadiene, styrene, and secondary structure modifier is 200~300:100:0.2~0.5:30~40:20~30:0.5~1.

0.

8. 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.

1.

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

10. 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 2.3% to 3.4%.

11. A cold-resistant and compression-resistant hydrogenated nitrile butadiene rubber for oilfield use, prepared by any one of claims 1-10.

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