A tear-resistant, cold-resistant hydrogenated nitrile rubber for oil fields and a method for preparing the same

Abstract

The application discloses an oilfield anti-tearing and cold-resistant hydrogenated butyl nitrile rubber and a preparation method thereof, and the preparation method comprises the following steps: (1) preparing a macromolecular complex functionalized grafting agent, and (2) preparing the oilfield anti-tearing and cold-resistant hydrogenated butyl nitrile rubber; the macromolecular complex functionalized grafting agent has the following structure: wherein R is a linear alkyl group with 1-6 carbon atoms; B is a capped 1,3-butadiene; n and m are the number of repeating units, n is a positive integer greater than or equal to 1, and m is a positive integer greater than or equal to 1; and the number average molecular weight (Mn) of the macromolecular complex functionalized grafting agent is 7000-8000. The preparation method of the oilfield anti-tearing and cold-resistant hydrogenated butyl nitrile rubber has the characteristics of green environmental protection, high modification efficiency, 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 tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oilfield use prepared by a macromolecular composite functionalized grafting agent, 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. With minimum temperatures reaching around -50°C, oil drilling equipment faces extremely demanding low-temperature operating environments, placing exceptionally high requirements on the cold resistance of rubber sealing materials.

[0004] In the prior art, 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 oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber with a tear strength ≥74KN / m and a glass transition temperature Tg <-75℃, meeting the requirements for use in the range of -75℃ to -78℃. The invention first hydrolyzes 2,4,6-tribromophenylallyl ether to synthesize 2,4,6-trihydroxyphenylallyl ether. Then, it uses 2,4,6-trihydroxyphenylallyl ether and 4-hydroxy-3-alkoxy-1-propenylbenzene to prepare a macromolecular composite functionalized monomer. Next, it anionicly polymerizes the macromolecular composite functionalized monomer and the reactive monomer p-alkylstyrene to prepare a macromolecular composite functionalized grafting agent with free radical reactivity. Finally, it grafts the macromolecular composite functionalized grafting agent onto the main chain of hydrogenated nitrile butadiene rubber to prepare oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber. This method not only solves the problem of easy crystallization of hydrogenated nitrile butadiene rubber, but also avoids the problem of decreased tear strength due to decreased crystallinity. This allows hydrogenated nitrile butadiene rubber to exhibit excellent cold resistance while maintaining sufficient tear strength, achieving a balance between cold resistance and tear strength. This meets the oil well operation requirements of submersible screw pump stator rubber materials under low-temperature conditions of -75℃.

[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 tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields, the method comprising the following steps:

[0010] (1) Preparation of macromolecular composite functionalized grafting agents:

[0011] Preparation of 2,4,6-trihydroxyphenylallyl ether: Argon gas was introduced into the polymerization reactor for purging. Deionized water, 2,4,6-tribromophenylallyl ether, and NaOH aqueous solution were added to the polymerization reactor in sequence. The mixture was stirred, mixed, heated, and reacted. Finally, the mixture was extracted, separated, washed, and dried to obtain 2,4,6-trihydroxyphenylallyl ether.

[0012] b. Preparation of macromolecular composite functionalized monomers: Argon gas was introduced into the polymerization reactor to replace the system. Solvent, 4-hydroxy-3-alkoxy-1-propenylbenzene, 2,4,6-trihydroxyphenylallyl ether, and structure modifier were added to the polymerization reactor in sequence. The temperature was raised, and initiator 1 was added to the polymerization reactor for reaction. Finally, 1,3-butadiene was added to the polymerization reactor for end-capping. The reaction continued until no free monomers were present. The solution was wet coagulated and dried to obtain macromolecular composite functionalized monomers.

[0013] Preparation of macromolecular composite functionalized grafting agent: In a polymerization reactor, argon gas is introduced to replace the system. Solvent, p-alkylstyrene, and structure modifier are added to the polymerization reactor in sequence. The temperature is raised, and initiator 1 is added to react and form p-alkylstyrene homopolymer segments. Then, the macromolecular composite functionalized monomer and solution are mixed and stirred until completely dissolved. The solution is then added to the polymerization reactor and heated 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 then wet-coagulated and dried to obtain the macromolecular composite functionalized grafting agent.

[0014] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0015] 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 pressure is increased and the temperature is raised. After the reaction, the system is cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD < 90%).

[0016] Preparation of tear-resistant and cold-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. A macromolecular composite functionalized grafting agent is then 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 tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oilfields.

[0017] The macromolecular composite functionalized grafting agent has the following structure:

[0018]

[0019] Wherein, R is a C1-C6 straight-chain alkyl group; B is a capped 1,3-butadiene; n and m are the number of repeating units, n≥1 and m≥1 being positive integers; the number average molecular weight (Mn) of the macromolecular composite functionalized grafting agent is 7000-8000.

[0020] The p-alkylstyrene described in this invention is an aryl vinyl compound selected from p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-butylstyrene, p-pentylstyrene, and p-hexylstyrene, with p-methylstyrene being preferred.

[0021] The 4-hydroxy-3-alkoxy-1-propenylbenzene of this invention is an unsaturated organic compound selected from one of 4-hydroxy-3-methoxy-1-propenylbenzene, 4-hydroxy-3-ethoxy-1-propenylbenzene, 4-hydroxy-3-propoxy-1-propenylbenzene, 4-hydroxy-3-butoxy-1-propenylbenzene, 4-hydroxy-3-pentoxy-1-propenylbenzene, and 4-hydroxy-3-hexyloxy-1-propenylbenzene, preferably 4-hydroxy-3-ethoxy-1-propenylbenzene.

[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 DCP, and its addition amount is 0.2 to 0.5 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 a polymerization system, capable of adjusting the reactivity ratio between alkylstyrene and 1,3-butadiene, enabling random copolymerization of the two. 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, chloroform, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene, and xylene, with cyclohexane being preferred.

[0027] In step (1)a of this invention, the mass ratio of deionized water, 2,4,6-tribromophenylallyl ether, and NaOH aqueous solution is 300-400:100:20-30.

[0028] In step (1)a of the present invention, the mass concentration of the NaOH aqueous solution is 10% to 20%.

[0029] In step (1)a of the present invention, the temperature is raised to 130-140°C; the reaction time is 6-8 hours.

[0030] In step (1)a of the present invention, the yield of the 2,4,6-trihydroxyphenyl allyl ether is 80% to 83%.

[0031] In step (1)b of the present invention, the mass ratio of the solvent, 4-hydroxy-3-alkoxy-1-propenylbenzene, 2,4,6-trihydroxyphenylallyl ether, structure modifier, and 1,3-butadiene is 200-300:30-40:60-70:0.3-0.5:2-5.

[0032] In step (1)b of the present invention, the temperature is raised to 70-80°C.

[0033] In step (1)b of the present invention, the reaction time after adding initiator 1 is 90-100 min; the reaction time for end-capping with 1,3-butadiene is 30-40 min.

[0034] In step (1)c of the present invention, the mass ratio of the solvent, p-alkylstyrene, structure modifier, macromolecular composite functionalized monomer, solution, and 1,3-butadiene is 200-300:100:0.3-0.6:20-30:100-200:2-5.

[0035] In step (1)c of the present invention, after adding initiator 1, the reaction temperature is 50-60°C and the time is 80-90 min.

[0036] In step (1)c of the present invention, the stirring and dissolving time is 80-90 min.

[0037] In step (1)c of this invention, after adding the macromolecular composite functionalized monomer and solution, the temperature is raised to 80-90℃ and the reaction time is 80-90 min; the reaction time for adding 1,3-butadiene for end-capping is 30-40 min.

[0038] 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.

[0039] In step (2)a of the present invention, the mass fraction of nitrile rubber in the adhesive solution is 3% to 6%.

[0040] 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%.

[0041] 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.

[0042] In step (2)a of the present invention, the degree of hydrogenation of the HNBR rubber is less than 90%.

[0043] In step (2)b of the present invention, the mass ratio of the HNBR rubber, the macromolecular composite functionalized grafting agent, and chlorobenzene is 100:2-5:50-100.

[0044] In step (2)b of the present invention, the mass fraction of HNBR rubber in the adhesive solution is 6% to 9%.

[0045] In step (2)b of the present invention, the reaction temperature after adding the mixture of initiator 2 and chlorobenzene is 70-80°C and the reaction time is 12.0-13.0hr.

[0046] In step (2)b of the present invention, the grafting rate of the oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile rubber is 1.8% to 3.9%.

[0047] 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.

[0048] The reaction vessel described in this invention can be a loop reactor or a batch reactor, preferably a batch reactor.

[0049] 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.

[0050] The present invention also provides a tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields prepared by the above method.

[0051] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0052] (1) The macromolecular composite functionalized monomer prepared by the present invention is prepared by anionic polymerization of 2,4,6-trihydroxyphenylallyl ether and 4-hydroxy-3-alkoxy-1-propenylbenzene. This long-chain monomer integrates alkoxy, polyhydroxy and phenyl groups on a macromolecular chain, making full use of the "cumulative effect" of macromolecules and the "group effect" of ether, polyhydroxy and alkoxy groups. It can effectively destroy the crystallinity of HNBR, while also using the rigidity of phenyl to avoid the decrease in tear strength caused by the decrease in the crystallinity of HNBR. It can prepare a tear-resistant and cold-resistant hydrogenated nitrile rubber for oilfield use with a glass transition temperature Tg < -75℃, which can meet the requirements of oil well operation under low temperature conditions of -75℃.

[0053] (2) The macromolecular composite functionalized grafting agent prepared by the present invention integrates the alkyl styrene homopolymer segments and the macromolecular composite functionalized monomers into a macromolecular chain. It fully utilizes the "cumulative effect" of the alkyl styrene homopolymer and the "group effect" of the large steric hindrance and high rigidity of the polybenzene rings in the macromolecular composite functionalized monomers to produce a certain "synergistic effect", which can more effectively improve the tear strength of HNBR. At the same time, it avoids the damage to the crystallinity of HNBR caused by ether groups, polyhydroxy and alkoxy groups, which would lead to a decrease in the tear strength of HNBR. It can prepare a tear-resistant and cold-resistant hydrogenated nitrile rubber for oil fields with a raw rubber tear strength ≥74KN / m, which can meet the oil well operation requirements of submersible screw pump stator rubber materials.

[0054] (3) The macromolecular composite functionalized grafting agent prepared by the present invention can significantly improve the tear strength of HNBR and reduce the glass transition temperature (Tg) of HNBR with a low addition amount, and achieves high efficiency in modification in achieving a balance between the tear strength and cold resistance of HNBR.

[0055] (4) The preparation method of the oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile 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

[0056] 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.

[0057] (1) Source of raw materials:

[0058]

[0059]

[0060] (2) Analysis and testing methods:

[0061] 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:

[0062]

[0063] 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).

[0064] 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 .

[0065] 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:

[0066] Degree of hydrogenation (HD%) = 1 - Degree of unsaturation (U)

[0067] 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.

[0068] Tear strength: The method specified in standard GB / T 529-2009 shall be applied.

[0069] Example 1

[0070] (1) Preparation of macromolecular composite functionalized grafting agents:

[0071] Preparation of 2,4,6-trihydroxyphenylallyl ether: First, in a 5L stainless steel polymerization reactor with a jacket, argon gas was purged three times. Then, 1500 g of deionized water, 500 g of 2,4,6-tribromophenylallyl ether, and 100 g of 10% NaOH aqueous solution were added to the polymerization reactor in sequence. The mixture was stirred, mixed, and heated to 130°C. After reacting for 6.0 hours, the mixture was finally extracted, separated, washed, and dried to obtain 2,4,6-trihydroxyphenylallyl ether (yield 80%).

[0072] b. Preparation of macromolecular composite functionalized monomers: In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 2000g of cyclohexane, 300g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 700g of 2,4,6-trihydroxyphenyl allyl ether, and 3.0g of THF were added to the polymerization reactor in sequence. The temperature was raised to 70℃, and then 320mmol of n-butyllithium was added to the polymerization reactor and reacted for 90min. Finally, 20g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 30min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the macromolecular composite functionalized monomers.

[0073] Preparation of macromolecular composite functionalized grafting agent: In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 2000g of cyclohexane, 1000g of p-methylstyrene, and 3.0g of THF were added sequentially to the polymerization reactor. After heating to 50℃, 210mmol of n-butyllithium was added to initiate a reaction for 80min, forming p-methylstyrene segments. Then, 200g of macromolecular composite functionalized monomer and 1000g of cyclohexane were mixed and stirred for 80min until completely dissolved. This mixture was then added to the polymerization reactor and heated to 80℃ for another 80min. Finally, 20g of 1,3-butadiene was added to the polymerization reactor for a capping reaction for 30min until no free monomers remained. The resulting solution was then wet-coagulated and dried to obtain the macromolecular composite functionalized grafting agent (Mn = 7000).

[0074] (2) Preparation of tear-resistant and cold-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 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%).

[0076] Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfield use: 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, 4.0g of a macromolecular composite functionalized grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 70℃, a mixture of 0.40g of DCP and 100g of 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 tear-resistant and cold-resistant hydrogenated NBR for oilfield use (grafting rate 1.8%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0077] Example 2

[0078] (1) Preparation of macromolecular composite functionalized grafting agents:

[0079] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 1.

[0080] b. Preparation of macromolecular composite functionalized monomers: In a jacketed 10L stainless steel polymerization reactor, the system was purged three times with argon gas. 2200g of cyclohexane, 320g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 680g of 2,4,6-trihydroxyphenyl allyl ether, and 3.5g of THF were added to the polymerization reactor in sequence. The temperature was raised to 72℃, and then 316mmol of n-butyllithium was added to the polymerization reactor and reacted for 92min. Finally, 30g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 32min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the macromolecular composite functionalized monomers.

[0081] Preparation of macromolecular composite functionalized grafting agent: In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 2200g of cyclohexane, 1000g of p-methylstyrene, and 3.5g of THF were added sequentially to the polymerization reactor. After heating to 52℃, 207mmol of n-butyllithium was added to initiate a reaction for 82min, forming p-methylstyrene segments. Then, 220g of macromolecular composite functionalized monomer and 1200g of cyclohexane were mixed and stirred for 82min until completely dissolved. This mixture was then added to the polymerization reactor, heated to 82℃, and reacted for 82min. Finally, 26g of 1,3-butadiene was added to the polymerization reactor for a capping reaction for 32min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the macromolecular composite functionalized grafting agent (Mn = 7100).

[0082] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0083] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 1.

[0084] Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6.5% (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, 5.5g of a macromolecular composite functionalized grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 72℃, a mixture of 0.52g of DCP and 120g of chlorobenzene was added. After reacting for 12.2 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain tear-resistant and cold-resistant hydrogenated NBR for oilfield use (grafting rate 2.3%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0085] Example 3

[0086] (1) Preparation of macromolecular composite functionalized grafting agents:

[0087] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 1.

[0088] b. Preparation of macromolecular composite functionalized monomers: In a jacketed 10L stainless steel polymerization reactor, the system was purged with argon gas four times. 2400g of cyclohexane, 340g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 660g of 2,4,6-trihydroxyphenyl allyl ether, and 4.0g of THF were added to the polymerization reactor sequentially. The temperature was raised to 74℃, and then 309mmol of n-butyllithium was added to the polymerization reactor and reacted for 94min. Finally, 35g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 34min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the macromolecular composite functionalized monomers.

[0089] Preparation of macromolecular composite functionalized grafting agent: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas four times. 2400g of cyclohexane, 1000g of p-methylstyrene, and 4.0g of THF were added sequentially to the polymerization reactor. After heating to 54℃, 202 mmol of n-butyllithium was added to initiate a reaction for 84 min, forming p-methylstyrene segments. Then, 240g of macromolecular composite functionalized monomer and 1400g of cyclohexane were mixed and stirred for 84 min until completely dissolved. This mixture was then added to the polymerization reactor, heated to 84℃, and reacted for 84 min. Finally, 30g of 1,3-butadiene was added to the polymerization reactor for a capping reaction for 34 min until no free monomer remained. The resulting solution was wet-coagulated and dried to obtain the macromolecular composite functionalized grafting agent (Mn = 7400).

[0090] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0091] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 1.

[0092] Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (NBR) 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 four times for purging. Next, 6.3g of a macromolecular composite functionalized grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 74℃, a mixture of 0.61g of DCP and 140g of chlorobenzene was added. After reacting for 12.4 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain tear-resistant and cold-resistant hydrogenated NBR for oilfield use (grafting rate 2.8%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0093] Example 4

[0094] (1) Preparation of macromolecular composite functionalized grafting agents:

[0095] Preparation of 2,4,6-trihydroxyphenylallyl ether: First, in a 5L stainless steel polymerization reactor with a jacket, argon gas was purged four times. Then, 2000 g of deionized water, 500 g of 2,4,6-tribromophenylallyl ether, and 150 g of 20% NaOH aqueous solution were added to the polymerization reactor in sequence. The mixture was stirred, mixed, and heated to 140°C. After reacting for 8.0 hours, the mixture was finally extracted, separated, washed, and dried to obtain 2,4,6-trihydroxyphenylallyl ether (yield 83%).

[0096] b. Preparation of macromolecular composite functionalized monomers: In a jacketed 10L stainless steel polymerization reactor, the system was purged with argon gas four times. 2600g of cyclohexane, 350g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 650g of 2,4,6-trihydroxyphenyl allyl ether, and 4.3g of THF were added sequentially to the polymerization reactor. The temperature was raised to 76℃, and then 303mmol of n-butyllithium was added to the polymerization reactor and reacted for 96min. Finally, 40g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 36min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the macromolecular composite functionalized monomers.

[0097] Preparation of macromolecular composite functionalized grafting agent: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas four times. 2600g of cyclohexane, 1000g of p-methylstyrene, and 4.5g of THF were added sequentially to the polymerization reactor. After heating to 56℃, 197mmol of n-butyllithium was added to initiate a reaction for 86min, forming p-methylstyrene segments. Then, 260g of macromolecular composite functionalized monomer and 1600g of cyclohexane were mixed and stirred for 86min until completely dissolved. This mixture was then added to the polymerization reactor, heated to 86℃, and reacted for 86min. Finally, 35g of 1,3-butadiene was added to the polymerization reactor for a capping reaction for 36min until no free monomer remained. The resulting solution was wet-coagulated and dried to obtain the macromolecular composite functionalized grafting agent (Mn = 7600).

[0098] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0099] 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%).

[0100] Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 7.9% (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, 7.8g of a macromolecular composite functionalized grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 76℃, a mixture of 0.73g of DCP and 160g of chlorobenzene was added. After reacting for 12.5 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain tear-resistant and cold-resistant hydrogenated NBR for oilfield use (grafting rate 3.2%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0101] Example 5

[0102] (1) Preparation of macromolecular composite functionalized grafting agents:

[0103] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 4.

[0104] b. Preparation of macromolecular composite functionalized monomers: In a jacketed 10L stainless steel polymerization reactor, the system was purged with argon gas five times. 2800g of cyclohexane, 370g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 630g of 2,4,6-trihydroxyphenyl allyl ether, and 4.8g of THF were added sequentially to the polymerization reactor. The temperature was raised to 78℃, and then 297mmol of n-butyllithium was added to the polymerization reactor and reacted for 98min. Finally, 45g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 38min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the macromolecular composite functionalized monomers.

[0105] Preparation of macromolecular composite functionalized grafting agent: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas five times. 2800g of cyclohexane, 1000g of p-methylstyrene, and 5.2g of THF were added sequentially to the polymerization reactor. After heating to 57℃, 193mmol of n-butyllithium was added to initiate a reaction for 88min, forming p-methylstyrene segments. Then, 280g of macromolecular composite functionalized monomer and 1800g of cyclohexane were mixed and stirred for 88min until completely dissolved. This mixture was then added to the polymerization reactor, heated to 88℃, and reacted for 88min. Finally, 40g of 1,3-butadiene was added to the polymerization reactor for end-capping reaction for 38min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the macromolecular composite functionalized grafting agent (Mn = 7800).

[0106] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0107] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 4.

[0108] Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (NBR) for oilfield use: First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a rubber solution with a mass fraction of 8.4%. 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, 9.1g of a macromolecular composite functionalized grafting agent was added to the reactor, stirred, mixed, and heated. When the reactor temperature reached 78℃, a mixture of 0.84g of DCP and 180g of chlorobenzene was added. After reacting for 12.7 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain tear-resistant and cold-resistant hydrogenated NBR for oilfield use (grafting rate 3.5%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0109] Example 6

[0110] (1) Preparation of macromolecular composite functionalized grafting agents:

[0111] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 4.

[0112] b. Preparation of macromolecular composite functionalized monomers: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas five times. 3000g of cyclohexane, 400g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 600g of 2,4,6-trihydroxyphenyl allyl ether, and 5.0g of THF were added to the polymerization reactor sequentially. The temperature was raised to 80℃, and then 289 mmol of n-butyllithium was added to the polymerization reactor and reacted for 100 min. Finally, 50g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 40 min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the macromolecular composite functionalized monomers.

[0113] Preparation of macromolecular composite functionalized grafting agent: In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas five times. 3000g of cyclohexane, 1000g of p-methylstyrene, and 6.0g of THF were added sequentially to the polymerization reactor. After heating to 60℃, 187mmol of n-butyllithium was added to initiate a reaction for 90min, forming p-methylstyrene segments. Then, 300g of macromolecular composite functionalized monomer and 2000g of cyclohexane were mixed and stirred for 90min until completely dissolved. This mixture was then added to the polymerization reactor, heated to 90℃, and reacted for 90min. Finally, 50g of 1,3-butadiene was added to the polymerization reactor for a 40min end-capping reaction until no free monomer remained. The resulting solution was wet-coagulated and dried to obtain the macromolecular composite functionalized grafting agent (Mn = 8000).

[0114] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0115] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 4.

[0116] Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (NBR) 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, 10.0g of a macromolecular composite functionalized grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 80℃, a mixture of 1.00g of DCP and 200g of chlorobenzene was added. After reacting for 13.0 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain tear-resistant and cold-resistant hydrogenated NBR for oilfield use (grafting rate 3.9%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0117] Comparative Example 1

[0118] (1) Preparation of macromolecular composite functionalized grafting agents:

[0119] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 1.

[0120] b. Preparation of macromolecular composite functionalized monomers: Other conditions are the same as in Example 1, except that the amount of 2,4,6-trihydroxyphenyl allyl ether added in the preparation of macromolecular composite functionalized monomers is 400g. That is: in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas three times, and 2000g of cyclohexane, 300g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 400g of 2,4,6-trihydroxyphenyl allyl ether, and 3.0g of THF are added to the polymerization reactor in sequence. The temperature is raised to 70°C, and then 320mmol of n-butyllithium is added to the polymerization reactor and reacted for 90min. Finally, 20g of 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction is carried out for 30min until no free monomers are present. The solution is wet-coagulated and dried to obtain macromolecular composite functionalized monomer a.

[0121] Preparation of macromolecular composite functionalized grafting agent: Other conditions are the same as in Example 1, except that macromolecular composite functionalized monomers are not added during the preparation of the macromolecular composite functionalized grafting agent. Instead, macromolecular composite functionalized monomer a is added in an amount of 200g. That is, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas three times. 2000g of cyclohexane, 1000g of p-methylstyrene, and 3.0g of THF are added to the polymerization reactor in sequence. After heating to 50°C, 210mmol of n-butyllithium is added to start the reaction for 80min to form p-methylstyrene segments. Then, 200g of macromolecular composite functionalized monomer a and 1000g of cyclohexane are mixed and stirred for 80min until completely dissolved. This mixture is then added to the polymerization reactor and heated to 80°C for 80min. Finally, 20g of macromolecular composite functionalized monomer a is added to the polymerization reactor. 1,3-Butadiene was subjected to a capping reaction for 30 minutes until no free monomers were present. The adhesive solution was then wet-coagulated and dried to obtain macromolecular composite functionalized grafting agent a (Mn is 6700).

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

[0123] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 1.

[0124] Preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber: Other conditions are the same as in Example 1, except that no macromolecular composite functionalized grafting agent is added during the preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber. Instead, macromolecular composite functionalized grafting agent a is added, with an addition amount of 4.0g. That is: 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 replace it three times. Then, 4.0g of macromolecular composite functionalized grafting agent a is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 70°C, a mixture of 0.40g of DCP and 100g 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 oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (grafting rate 1.8%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0125] Comparative Example 2

[0126] (1) Preparation of macromolecular composite functionalized grafting agents:

[0127] Preparation of macromolecular composite functionalized monomers: Other conditions are the same as in Example 2, except that 2,4,6-trihydroxyphenyl allyl ether is not added in the preparation of macromolecular composite functionalized monomers. That is: in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas three times, and 2200g of cyclohexane, 320g of 4-hydroxy-3-alkoxy-1-propenylbenzene and 3.5g of THF are added to the polymerization reactor in sequence. The temperature is raised to 72°C, and then 316mmol of n-butyllithium is added to the polymerization reactor and reacted for 92min. Finally, 30g of 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction is carried out for 32min until no free monomers are present. The solution is wet coagulated and dried to obtain macromolecular composite functionalized monomer b.

[0128] c. Preparation of macromolecular composite functionalized grafting agent: Other conditions are the same as in Example 2, except that macromolecular composite functionalized monomers are not added during the preparation of the macromolecular composite functionalized grafting agent. Instead, macromolecular composite functionalized monomer b is added in an amount of 220g. That is, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas three times. 2200g of cyclohexane, 1000g of p-methylstyrene, and 3.5g of THF are added to the polymerization reactor in sequence. After heating to 52°C, 207mmol of n-butyllithium is added to start the reaction for 82min to form p-methylstyrene segments. Then, 220g of macromolecular composite functionalized monomer b and 1200g of cyclohexane are mixed and stirred for 82min until completely dissolved. This mixture is then added to the polymerization reactor and heated to 82°C for 82min. Finally, 26g of [unspecified substance] is added to the polymerization reactor. 1,3-Butadiene was subjected to a capping reaction for 32 minutes until no free monomers were present. The adhesive solution was then wet-coagulated and dried to obtain macromolecular composite functionalized grafting agent b (Mn is 6300).

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

[0130] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 2.

[0131] Preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (NBR): Other conditions are the same as in Example 2, except that no macromolecular composite functionalized grafting agent is added during the preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber. Instead, macromolecular composite functionalized grafting agent b is added, with an addition amount of 5.5g. Specifically: 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 purge it three times. Next, 5.5g of macromolecular composite functionalized grafting agent b is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 72°C, a mixture of 0.52g of DCP and 120g of chlorobenzene is added. After reacting for 12.2 hours, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (grafting rate 1.7%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0132] Comparative Example 3

[0133] (1) Preparation of macromolecular composite functionalized grafting agents:

[0134] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 3.

[0135] b. Preparation of macromolecular composite functionalized monomers: Other conditions are the same as in Example 3, except that 2,4,6-trihydroxyphenyl allyl ether is not added during the preparation of macromolecular composite functionalized monomers. Instead, 3,4-dihydroxystyrene is added in an amount of 660g. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas four times. 2400g of cyclohexane, 340g of 4-hydroxy-3-alkoxy-1-propenylbenzene, 660g of 3,4-dihydroxystyrene, and 4.0g of THF are added to the polymerization reactor in sequence. The temperature is raised to 74°C, and then 309 mmol of n-butyllithium is added to the polymerization reactor and reacted for 94 min. Finally, 35g of 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction is continued for 34 min until no free monomers are present. The solution is then wet-coagulated and dried to obtain macromolecular composite functionalized monomer c.

[0136] Preparation of macromolecular composite functionalized grafting agent c: Other conditions are the same as in Example 3, except that macromolecular composite functionalized monomer c is not added during the preparation of the macromolecular composite functionalized grafting agent. Instead, macromolecular composite functionalized monomer c is added in an amount of 240g. That is, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas four times. 2400g of cyclohexane, 1000g of p-methylstyrene, and 4.0g of THF are added to the polymerization reactor in sequence. After heating to 54°C, 202mmol of n-butyllithium is added to start the reaction for 84min to form p-methylstyrene segments. Then, 240g of macromolecular composite functionalized monomer c and 1400g of cyclohexane are mixed and stirred to dissolve for 84min until completely dissolved. This is then added to the polymerization reactor and heated to 84°C for 84min. Finally, 30g of [unspecified substance] is added to the polymerization reactor. 1,3-Butadiene was subjected to a capping reaction for 34 minutes until no free monomers were present. The adhesive solution was then wet-coagulated and dried to obtain a macromolecular composite functionalized grafting agent c (Mn = 7100).

[0137] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0138] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 3.

[0139] Preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber: Other conditions are the same as in Example 3, except that no macromolecular composite functionalized grafting agent is added during the preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber. Instead, macromolecular composite functionalized grafting agent c is added, with an addition amount of 6.3g. 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, 6.3g of macromolecular composite functionalized grafting agent c is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 74°C, a mixture of 0.61g of DCP and 140g of chlorobenzene is added. After reacting for 12.4 hours, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (grafting rate 2.5%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0140] Comparative Example 4

[0141] (1) Preparation of macromolecular composite functionalized grafting agents:

[0142] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 4.

[0143] Preparation of macromolecular composite functionalized grafting agent: Other conditions are the same as in Example 4, except that no macromolecular composite functionalized monomer is added during the preparation of the macromolecular composite functionalized grafting agent. Instead, 2,4,6-trihydroxyphenyl allyl ether is added in an amount of 260g. Specifically, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas four times. 2600g of cyclohexane, 1000g of p-methylstyrene, and 4.5g of THF are added to the polymerization reactor sequentially. After heating to 56°C, 197mmol of n-butyllithium is added to initiate the reaction for 86min, forming p-methylstyrene segments. Then, 260g of 2,4,6-trihydroxyphenyl allyl ether and 1600g of cyclohexane are mixed and stirred for 86min until completely dissolved. This mixture is then added to the polymerization reactor, heated to 86°C, and reacted for 86min. Finally, 35g of [unspecified substance] is added to the polymerization reactor. 1,3-Butadiene was subjected to a capping reaction for 36 minutes until no free monomers were present. The adhesive solution was then wet-coagulated and dried to obtain a macromolecular composite functionalized grafting agent d (Mn = 5600).

[0144] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0145] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 4.

[0146] Preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber: Other conditions are the same as in Example 4, except that no macromolecular composite functionalized grafting agent is added during the preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber. Instead, macromolecular composite functionalized grafting agent d is added, with an addition amount of 7.8g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a 7.9% 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, 7.8g of macromolecular composite functionalized grafting agent d is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 76°C, a mixture of 0.73g of DCP and 160g of chlorobenzene is added. After reacting for 12.5 hours, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (grafting rate 3.1%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0147] Comparative Example 5

[0148] (1) Preparation of macromolecular composite functionalized grafting agents:

[0149] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 5.

[0150] b. Preparation of macromolecular complex functionalized monomers: Same as in Example 5.

[0151] Preparation of macromolecular composite functionalized grafting agent: Other conditions are the same as in Example 5, except that the amount of p-methylstyrene added in the preparation of the macromolecular composite functionalized grafting agent is 400.0 g. That is: in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas 5 times, and 2800 g of cyclohexane, 400 g of p-methylstyrene, and 5.2 g of THF are added to the polymerization reactor in sequence. After heating to 57°C, 193 mmol of n-butyllithium is added to start the reaction for 88 min to form p-methylstyrene segments; then 280 g of macromolecular composite functionalized monomer and 1800 g of cyclohexane are mixed and stirred to dissolve for 88 min until completely dissolved, and then added to the polymerization reactor. The temperature is raised to 88°C and the reaction is carried out for 88 min; finally, 40 g of p-methylstyrene is added to the polymerization reactor. 1,3-Butadiene was subjected to a capping reaction for 38 minutes until no free monomers were present. The adhesive solution was then wet-coagulated and dried to obtain a macromolecular composite functionalized grafting agent e (Mn = 6700).

[0152] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0153] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 5.

[0154] Preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber: Other conditions are the same as in Example 5, except that no macromolecular composite functionalized grafting agent is added during the preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber. Instead, macromolecular composite functionalized grafting agent e is added, with an addition amount of 9.1g. Specifically: First, 200g of HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.4%. 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, 9.1g of macromolecular composite functionalized grafting agent e is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 78°C, a mixture of 0.84g of DCP and 180g of chlorobenzene is added. After reacting for 12.7 hours, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (grafting rate 3.5%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0155] Comparative Example 6

[0156] (1) Preparation of macromolecular composite functionalized grafting agents:

[0157] Preparation of α-2,4,6-trihydroxyphenylallyl ether: Same as in Example 6.

[0158] b. Preparation of macromolecular composite functionalized monomers: Other conditions are the same as in Example 6, except that 4-hydroxy-3-alkoxy-1-propenylbenzene is not added during the preparation of macromolecular composite functionalized monomers. Instead, N-(hydroxymethyl)acrylamide is added in an amount of 400g. That is, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas 5 times. 3000g of cyclohexane, 400g of N-(hydroxymethyl)acrylamide, 600g of 2,4,6-trihydroxyphenyl allyl ether, and 5.0g of THF are added to the polymerization reactor in sequence. The temperature is raised to 80°C, and then 289mmol of n-butyllithium is added to the polymerization reactor and reacted for 100min. Finally, 50g of 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction is carried out for 40min until no free monomers are present. The solution is wet-coagulated and dried to obtain macromolecular composite functionalized monomer d.

[0159] Preparation of macromolecular composite functionalized grafting agent: Other conditions are the same as in Example 6, except that macromolecular composite functionalized monomers are not added during the preparation of the macromolecular composite functionalized grafting agent. Instead, macromolecular composite functionalized monomer d is added in an amount of 300g. That is, in a 10L stainless steel polymerization reactor with a jacket, the system is purged with argon gas 5 times. 3000g of cyclohexane, 1000g of p-methylstyrene, and 6.0g of THF are added to the polymerization reactor in sequence. After heating to 60°C, 187mmol of n-butyllithium is added to start the reaction for 90min to form p-methylstyrene segments. Then, 300g of macromolecular composite functionalized monomer d and 2000g of cyclohexane are mixed and stirred to dissolve for 90min until completely dissolved. This is then added to the polymerization reactor and heated to 90°C for 90min. Finally, 50g of [unspecified substance] is added to the polymerization reactor. 1,3-Butadiene was subjected to a capping reaction for 40 minutes until no free monomers were present. The adhesive solution was then wet-coagulated and dried to obtain a macromolecular composite functionalized grafting agent f (Mn = 7200).

[0160] (2) Preparation of tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields:

[0161] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 6.

[0162] Preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber: Other conditions are the same as in Example 6, except that no macromolecular composite functionalized grafting agent is added during the preparation of oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber. Instead, macromolecular composite functionalized grafting agent f is added, with an addition amount of 10.0g. Specifically: 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 purge five times. Then, 10.0g of macromolecular composite functionalized grafting agent f is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 80°C, a mixture of 1.00g of DCP and 200g of chlorobenzene is added. After reacting for 13.0hr, the mixture is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber (grafting rate 3.1%). Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0163] Table 1. Properties of tear-resistant and cold-resistant hydrogenated nitrile rubber for oilfield applications.

[0164]

[0165]

[0166] As shown in Table 1, the oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile rubber of the present invention has high tear strength and low glass transition temperature, and is suitable for oil well operation requirements of submersible screw pump stator rubber material with tear strength ≥74KN / m and ambient temperature of -75℃.

[0167] 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 tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oilfield use, characterized in that, Includes the following steps: (1) Preparation of macromolecular composite functionalized grafting agents: Preparation of 2,4,6-trihydroxyphenylallyl ether: Argon gas was introduced into the polymerization reactor for purging. Deionized water, 2,4,6-tribromophenylallyl ether, and NaOH aqueous solution were added sequentially to the polymerization reactor. The mixture was stirred, mixed, heated, and allowed to react. Finally, the mixture was extracted, separated, washed, and dried to obtain 2,4,6-trihydroxyphenylallyl ether. The mass ratio of the deionized water, 2,4,6-tribromophenylallyl ether, and NaOH aqueous solution was 300~400:100:20~30. b. Preparation of macromolecular composite functionalized monomers: Argon gas was introduced into the polymerization reactor to replace the system. Solvent, 4-hydroxy-3-alkoxy-1-propenylbenzene, 2,4,6-trihydroxyphenylallyl ether, and structure modifier were added to the polymerization reactor in sequence. The temperature was raised, and initiator 1 was added to the polymerization reactor for reaction. Finally, 1,3-butadiene was added to the polymerization reactor for end-capping. The reaction continued until no free monomers were present. The solution was wet coagulated and dried to obtain macromolecular composite functionalized monomers. Preparation of macromolecular composite functionalized grafting agent: In a polymerization reactor, argon gas is introduced to purge the system. Solvent, p-alkylstyrene, and structure modifier are added sequentially to the polymerization reactor. The temperature is raised, and initiator 1 is added to react and form p-alkylstyrene homopolymer segments. Then, the macromolecular composite functionalized monomer and solution are mixed and stirred until completely dissolved. The solution is then added to the polymerization reactor and heated to react. 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 the macromolecular composite functionalized grafting agent. The mass ratio of solvent, p-alkylstyrene, structure modifier, macromolecular composite functionalized monomer, solution, and 1,3-butadiene is 200~300:100:0.3~0.6:20~30:100~200:2~5. (2) Preparation of tear-resistant and cold-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 pressure is increased and the temperature is raised. After the reaction, the system is cooled, condensed, and vacuum dried to obtain HNBR rubber. Preparation of tear-resistant and cold-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. A macromolecular composite functionalized grafting agent is then 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 tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oilfields. The macromolecular composite functionalized grafting agent has the following structure: Wherein, R is a C1-C6 straight-chain alkyl group; B is a capped 1,3-butadiene; n and m are the number of repeating units, n≥1 and m≥1 being positive integers; the number average molecular weight (Mn) of the macromolecular composite functionalized grafting agent is 7000~8000.

2. The preparation method according to claim 1, characterized in that, The p-alkylstyrene is selected from one of p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-butylstyrene, p-pentylstyrene, and p-hexylstyrene.

3. 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.

4. 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 0.2 to 0.5 parts based on 100 parts by weight of HNBR rubber.

5. 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%.

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

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

8. The preparation method according to claim 1, characterized in that, In step (1)a, the mass concentration of the NaOH aqueous solution is 10%~20%.

9. The preparation method according to claim 1, characterized in that, In step (1)b, the mass ratio of the solvent, 4-hydroxy-3-alkoxy-1-propenylbenzene, 2,4,6-trihydroxyphenylallyl ether, structure modifier, and 1,3-butadiene is 200~300:30~40:60~70:0.3~0.5:2~5.

10. 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.

11. 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%.

12. The preparation method according to claim 1, characterized in that, In step (2)b, the mass ratio of HNBR rubber, macromolecular composite functionalized grafting agent, and chlorobenzene is 100:2~5:50~100.

13. The preparation method according to claim 1, characterized in that, In step (2)b, the grafting rate of the oilfield-grade tear-resistant and cold-resistant hydrogenated nitrile rubber is 1.8% to 3.9%.

14. A tear-resistant and cold-resistant hydrogenated nitrile butadiene rubber for oil fields, obtained by the preparation method according to any one of claims 1-13.

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