Compression-resistant and cold-resistant hydrogenated nitrile rubber for oil field and preparation method thereof

Abstract

The invention discloses compression-resistant and cold-resistant hydrogenated butadiene-acrylonitrile rubber for an oil field and a preparation method of the compression-resistant and cold-resistant hydrogenated butadiene-acrylonitrile rubber. The preparation method comprises the following steps: (1) preparing a macromolecular three-miktoarm star-shaped composite functional grafting agent; and (2) preparing the compression-resistant and cold-resistant hydrogenated butadiene-acrylonitrile rubber for the oil field. The macromolecular three-miktoarm star-shaped composite functional grafting agent has the following structure: # imgabs0 #, wherein BR is a 1, 3-butadiene homopolymer segment with wide vinyl distribution; sB is a random segment of styrene and 1, 3-butadiene; (S-B) is a transition section of styrene and 1, 3-butadiene; b is terminated 1, 3-butadiene; n, m and L are repeating unit numbers, and n > = 1, m > = 1 and L > = 1 are positive integers; the number-average molecular weight (Mn) of the macromolecular three-miktoarm star-shaped composite functional grafting agent is 6000 to 9000, and the molecular weight distribution (Mw / Mn) of the macromolecular three-miktoarm star-shaped composite functional grafting agent is 12.13 to 13.94. The preparation method of the compression-resistant and cold-resistant hydrogenated butadiene-acrylonitrile rubber for the oil field has the characteristics of environmental friendliness, efficient modification effect, low modifier dosage, commercially available and easily available raw materials, suitability for industrial production and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber, and specifically relates to a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields prepared by a macromolecular three-arm star-shaped composite functional grafting agent and a preparation method thereof. Background Art

[0002] Hydrogenated nitrile rubber (HNBR for short) is prepared by selective hydrogenation of carbon-carbon double bonds in nitrile rubber. Therefore, HNBR not only retains the oil resistance, corrosion resistance and elasticity of NBR, but also exhibits excellent aging resistance and high temperature resistance. The mechanical properties such as tensile strength, elongation at break, wear resistance and hardness are improved. It is widely used in oil exploration equipment such as pump pistons, rotary hoses, valve seals, drill pipe shields, etc.

[0003] Although hydrogenation of carbon-carbon double bonds gives HNBR very excellent performance, it also brings a serious defect to HNBR materials. The main chain of hydrogenated nitrile rubber (NBR) is a highly ordered polyethylene structure, which is very easy to form a crystalline structure and causes an increase in Tg. Therefore, the cold resistance of HNBR products is poor. Since most of my country's oil drilling business is concentrated in the western and northeastern regions, the lowest temperature in these regions can reach about -50℃. Oil drilling equipment faces an application environment under low temperature conditions, which puts forward extremely high requirements on the cold resistance of rubber sealing materials.

[0004] In the prior art, there are many patent documents reporting on the preparation method of low temperature resistant hydrogenated nitrile rubber. For example:

[0005] CN 106349410 B discloses a special hydrogenated nitrile rubber with compression cold resistance and a preparation method thereof, wherein the rubber main chain contains epoxy groups, and some of the epoxy groups are also connected to ester side groups; the ester side groups are generated by the ring-opening reaction of C6-C24 acid anhydride and the epoxy groups. The preparation method comprises introducing epoxy groups into the main chain of the rubber molecule, and then reacting some of the epoxy groups with acid anhydride under the action of a catalyst to introduce ester groups to obtain a 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 to 3.25×10 5 , weight average molecular weight is 3.02~9.32×10 5, the polydispersity coefficient is 2.0-2.7; the low-temperature grade hydrogenated nitrile rubber raw rubber has a hydrogenation degree of more than 90% and a glass transition temperature of -38°C to -42°C. CN 112592461 B discloses a modified hydrogenated nitrile rubber material with the characteristics of low temperature resistance and high damping, and its preparation method and application. The modified hydrogenated nitrile 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 rubber compound and a banburying preparation method thereof, which mainly comprises blending and banburying hydrogenated nitrile raw rubber, a plasticizer and a hardness regulator, and finally obtains a cold-resistant hydrogenated nitrile rubber compound having a Shore A hardness of 67±5, a tensile strength ≥14MPa, an elongation at break ≥180%, a compression permanent deformation ≤35%, and a 45°C compression cold resistance coefficient ≥0.16. CN 105754164A discloses a low-temperature resistant rubber material, although the cold resistance of the material is improved, the addition of the plasticizer dioctyl phthalate (DOP) reduces the mechanical properties and oil resistance of the material, and DOP is not environmentally friendly and is easy to precipitate. Zhang Dongheng et al. disclosed that ethylene propylene rubber (EPDM) and HNBR were blended to improve the cold resistance of HNBR. When the EPDM addition amount was 15%, the Tg dropped by 3°C. However, when the EPDM addition amount was further increased, the Tg of the blended rubber did not drop any more (Synthetic Rubber Industry, 2002, 25(1): ).

[0006] In the above-mentioned prior art, although the cold resistance of hydrogenated nitrile rubber can be improved to a certain extent by adding small molecule modifiers, copolymerization and blending, these methods still have certain limitations, and the preparation methods thereof have the problems of complex process, difficulty in actual operation, large addition amount, high cost, and unclear modification effect. Summary of the invention

[0007] In order to solve the problems existing in the prior art, a method for preparing a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields is provided, which has a compression permanent deformation resistance of ≤11% and a glass transition temperature Tg<-74°C and can meet the requirements of use within the range of -74°C to -76°C. The invention first uses 1,3-butadiene, dihydromyrcenol and N-(4-hydroxybutyl) acrylamide to prepare a macromolecular composite functional long-chain monomer; secondly, an anionic polymerization method is used, and the reaction monomers are styrene, 1,3-butadiene and macromolecular composite functional long-chain monomers. Through variable temperature polymerization, variable speed polymerization and coupling agent trihalogenated benzene coupling, a macromolecular three-arm star-shaped composite functional grafting agent with wide vinyl distribution and random gradient segments is prepared. The grafting agent gives hydrogenated nitrile rubber very excellent deformation resistance and cold resistance, and achieves a balance between the deformation resistance and low temperature resistance of hydrogenated nitrile rubber, which is very suitable for oil well operations with compression requirements.

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

[0009] In order to achieve the above object, the present invention provides a method for preparing compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, the preparation method comprising the following steps:

[0010] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0011] a. Preparation of macromolecular composite functional long-chain monomers: In a polymerization kettle, argon is introduced to replace the system, and a solvent, dihydromyrcenol, N-(4-hydroxybutyl)acrylamide, and a structure regulator are added to the polymerization kettle in sequence, and the temperature is raised, and then initiator 1 is added to the polymerization kettle for reaction; finally, 1,3-butadiene is added to the polymerization kettle for end-capping, and the reaction is continued until no free monomers are present, and the colloid is wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer;

[0012] b Preparation of SB / (S→B) copolymer: In a polymerization kettle, argon gas is introduced to replace the system, and a solvent and a structure regulator are added to the polymerization kettle in sequence, the temperature is raised, and an initiator 1 is added. Subsequently, 1,3-butadiene and styrene are stirred and mixed, and then added to the polymerization kettle to react until no free monomer is present. The colloid is wet-coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer;

[0013] c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a polymerization kettle, argon is introduced to replace the system, and solvent 1, 1,3-butadiene, and a structure regulator are added to the polymerization kettle in sequence, the temperature is raised, and initiator 1 is added. The reaction is a temperature-variable polymerization. Within 50 to 70 minutes, the temperature is gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reaches 100%, the temperature is raised and a coupling agent is added to carry out a coupling reaction; then the SB / (S→B) copolymer and the solution are mixed and stirred to dissolve, and then the mixture is added to the polymerization kettle for a coupling reaction until it is completely dissolved; finally, the macromolecular composite functionalized long-chain monomer is mixed with solvent 2 and stirred to dissolve, and then the mixture is added to the polymerization kettle for a coupling reaction until no free monomer exists. The glue solution is wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functionalized grafting agent;

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

[0015] a Preparation of hydrogenated nitrile rubber (HNBR): dissolve nitrile rubber in chlorobenzene solution to prepare a rubber solution, then add the rubber solution into a reactor and introduce inert gas to remove the air in the reactor, then remove the inert gas in the reactor with hydrogen, add a xylene solution of Grubbs I catalyst under nitrogen protection, pressurize, heat, react, cool the system, condense, and vacuum dry to obtain HNBR rubber;

[0016] b. Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution, and then the glue solution is added to a reactor, and an inert gas is introduced for replacement, and then a macromolecular three-arm star-shaped composite functionalized grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of initiator 2 and chlorobenzene is added, reacted, flocculated, washed, and dried to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields;

[0017] The macromolecular three-arm star-shaped composite functionalized grafting agent has the following structure:

[0018]

[0019] Among them, BR is a 1,3-butadiene homopolymer segment with a wide vinyl distribution; SB is a random segment of styrene and 1,3-butadiene; (S→B) is a gradient segment of styrene and 1,3-butadiene; B is a terminal 1,3-butadiene; n, m, L are positive integers of the number of repeating units, n≥1, m≥1, L≥1; the number average molecular weight (Mn) of the macromolecular three-arm star-shaped composite functionalized grafting agent is 6000-9000, and the molecular weight distribution (Mw / Mn) is 12.13-13.94.

[0020] The initiator 1 of the present invention is a hydrocarbon monolithium compound, namely 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 to 20 carbon atoms. The hydrocarbon monolithium compound is selected from one of n-butyl lithium, sec-butyl lithium, methylbutyl lithium, phenylbutyl lithium, naphthalene lithium, cyclohexyl lithium and dodecyl lithium, preferably n-butyl lithium. The amount of organic lithium added is determined by the molecular weight of the designed polymer.

[0021] The initiator 2 described in the present invention is an organic peroxide, selected from one of diacetyl peroxide, diisobutyryl peroxide, cumene hydroperoxide, dicumyl peroxide (DCP) and dibenzoyl peroxide (BPO), preferably BPO, and its addition amount is 0.1 to 0.3 parts based on 100 parts by mass of HNBR rubber.

[0022] The nitrile rubber of the present invention is copolymerized by emulsion polymerization of 1,3-butadiene and acrylonitrile, wherein the acrylonitrile content of the nitrile rubber is 20wt% to 42wt%, preferably 22wt% to 35wt%.

[0023] The coupling agent of the present invention is one of 1,3,5-trichlorobenzene and 1,3,5-tribromobenzene, preferably 1,3,5-trichlorobenzene. The amount of the coupling agent used depends on the amount of the initiator 1. The excess coupling agent is gradually polymerized to eventually form a star polymer with a hetero-arm structure. The molar ratio of the total amount of the initiator 1 to the coupling agent is 3.0 to 4.0.

[0024] The structure regulator of the present invention is a polar organic compound that produces a solvation effect in the polymerization system, and can adjust the reactivity ratio of styrene and butadiene to make the two copolymerize randomly. This type of polar organic compound is selected from one of diethylene glycol dimethyl ether (2G), tetrahydrofuran (THF), ethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME), and triethylamine, preferably tetrahydrofuran (THF).

[0025] The solvent, solvent 1, solvent 2 or solution described in the present invention can be selected from one of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene and xylene, preferably cyclohexane.

[0026] In step (1) a of the present invention, the mass ratio of the solvent, dihydromyrcenol, N-(4-hydroxybutyl)acrylamide, structure regulator and 1,3-butadiene is 200-300:60-70, 30-40:0.1-0.3:2-5.

[0027] In step (1) a of the present invention, the temperature is raised to 50-60°C.

[0028] In step (1) a of the present invention, the time for adding initiator 1 to react is 70 to 80 minutes; the time for adding 1,3-butadiene to perform end-capping reaction is 30 to 40 minutes.

[0029] In step (1) b of the present invention, the mass ratio of the solvent, the structure regulator, 1,3-butadiene and styrene is 300-400: 0.1-0.4: 100: 30-40.

[0030] In step (1) b of the present invention, the temperature is raised to 60-70°C.

[0031] In step (1) b of the present invention, the stirring and mixing time is 20 to 30 minutes; the reaction time is 70 to 80 minutes, the initial feeding rate is >8.0% mixture / min, and the extent of the reduction in feeding rate depends on the reaction time.

[0032] In step (1) c of the present invention, the mass ratio of the solvent 1, 1,3-butadiene, structure regulator, SB / (S→B) copolymer, solution, macromolecular composite functionalized long-chain monomer, and solvent 2 is 200-300:100:0.05-0.1:20-30:100-200:4-7:100-150.

[0033] In step (1) c of the present invention, after the conversion rate of 1,3-butadiene monomer reaches 100%, the temperature is raised to 80° C. to 90° C.

[0034] In step (1) c of the present invention, the coupling reaction time after adding the coupling agent is 70 min to 80 min; the coupling reaction time after adding the SB / (S→B) copolymer and the solution is 90 min to 100 min; and the coupling reaction time after adding the macromolecular composite functionalized long-chain monomer and the solvent is 70 min to 80 min.

[0035] In step (1) c of the present invention, the stirring and dissolving time after adding the SB / (S→B) copolymer and the solution is 70 to 80 minutes; the stirring and dissolving time after adding the macromolecular composite functionalized long-chain monomer and the solvent is 60 to 70 minutes.

[0036] In step (2) a of the present invention, the mass ratio of the nitrile rubber to the Grubbs I catalyst is 100:0.02-0.1.

[0037] In step (2) a of the present invention, the mass fraction of nitrile rubber in the rubber solution is 3% to 6%.

[0038] In step (2) a of the present invention, the mass concentration of the Grubbs I catalyst in the xylene solution of the Grubbs I catalyst is 5% to 10%.

[0039] In step (2) a of the present invention, the pressurization is performed to a pressure of 11 to 14 MPa; the heating is performed to a temperature of 100 to 120° C.; and the reaction time is 9 to 11 hr.

[0040] In step (2) a of the present invention, the degree of hydrogenation of the HNBR rubber is HD<90%.

[0041] In step (2) b of the present invention, the mass ratio of the HNBR rubber, the macromolecular three-arm star-shaped composite functionalized grafting agent, and chlorobenzene is 100:2-4:50-100.

[0042] In step (2) b of the present invention, the mass fraction of HNBR rubber in the rubber solution is 6% to 9%.

[0043] In step (2) b of the present invention, the reaction temperature is 80-90° C. and the reaction time is 11.0-12.0 hr.

[0044] In step (2) b of the present invention, the grafting rate of the compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields is 1.9% to 2.7%.

[0045] The polymerization reaction of the present invention is carried out in an oxygen-free, water-free and inert gas environment. The inert gas is nitrogen or a gas of a Group 0 element in the periodic table except radon, preferably nitrogen.

[0046] The reactor described in the present invention can be a loop reactor or a tank reactor, preferably a tank reactor.

[0047] The pressurization in step (2) a of the present invention is achieved by adding hydrogen. The amount of hydrogen added is well known to those skilled in the art and is within the conventional addition range in the prior art, and is not particularly limited in the present invention.

[0048] The present invention also provides a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields obtained by the preparation method.

[0049] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0050] (1) The present invention combines three chain segments with different microstructures on a macromolecular chain to form a three-arm star structure through the design of a three-arm star structure, so that the performance of different chain segments can be organically combined and work synergistically. By utilizing the wide vinyl distribution in the BR chain segment, the randomness and gradual change of the -SB / (S→B)- chain segment, and the different reactivity ratios and steric hindrance effects of each chain segment in the arm structure, the disorder of the molecular chain segment increases during the graft polymerization of HNBR, which significantly destroys the regularity of the molecular chain, making the molecular weight distribution significantly broadened, ensuring that HNBR can obtain good viscoelastic properties, greatly improving the compression set resistance of HNBR, and being able to prepare a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields with a compression set of ≤11% of the raw rubber.

[0051] (2) The macromolecular composite functional long-chain monomer prepared by the present invention is prepared by anionic polymerization of dihydromyrcenol and N-(4-hydroxybutyl) acrylamide. This long-chain monomer integrates ether groups, amide groups and hydroxyl groups containing long carbon chains on a macromolecular chain, fully utilizing the "aggregation effect" of macromolecules and the "group effect" of hydroxyl groups and amide groups, which can effectively destroy the crystallinity of HNBR, and at the same time produce a certain "synergistic effect" with the three-arm star structure, which can more effectively reduce the glass transition temperature (Tg) of HNBR, and can prepare compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields with a glass transition temperature Tg of raw rubber <-74°C, which is suitable for oil well operations under low temperature conditions of -74°C.

[0052] (3) The macromolecular three-arm star-shaped composite functionalized grafting agent prepared by the present invention can significantly improve the compression set resistance and reduce the glass transition temperature (Tg) of HNBR with a low addition amount, and achieve a good "synergistic effect" in achieving a balance between compression set resistance and cold resistance.

[0053] (4) The method for preparing the compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields of the present invention is green and environmentally friendly, has a high modification effect, uses a low amount of modifier, has readily available raw materials on the market, and is suitable for industrial production. DETAILED DESCRIPTION

[0054] The following examples and comparative examples are listed to illustrate the effects of the present invention, but the protection scope of the present invention is not limited to these examples and comparative examples. The raw materials used in the examples are all industrial grade and used after purification without other special requirements. The "parts" described in the examples and comparative examples are all parts by mass.

[0055] (1) Source of raw materials:

[0056]

[0057]

[0058] (2) Analytical testing methods:

[0059] Determination of grafting rate: Take about 4g of sample from the three-necked bottle with a pipette and put it into a weighing bottle. After weighing, add 2-3 drops of hydroquinone solution and dry to constant weight. Then put the sample in a Soxhlet fat extractor and extract it with toluene in a 90℃ water bath for 24 hours, and then dry it to constant weight. Calculate the monomer grafting rate according to the following formula:

[0060]

[0061] Where: m0 is the total mass of the mortar (g); m is the mass of the sample weighed after the reaction (g); 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).

[0062] Molecular weight determination: The determination was performed using a 2414 gel permeation chromatograph (GPC) produced by Waters, USA. The polystyrene standard was used as the calibration curve, the mobile phase was tetrahydrofuran, the column temperature was 40°C, 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 .

[0063] Determination of HNBR hydrogenation degree: Using nuclear magnetic resonance hydrogen spectrum ( 1 The degree of hydrogenation of hydrogenated nitrile rubber is calculated by HNMR (HNMR), and the main method is as follows: 1. The product is completely dissolved in deuterated chloroform to prepare a nuclear magnetic resonance hydrogen spectrum sample; 2. After measuring the nuclear magnetic resonance hydrogen spectrum, its spectrum is analyzed: The degree of hydrogenation of hydrogenated nitrile rubber is measured by nuclear magnetic resonance hydrogen spectrum, and is calculated according to the following method: the proton characteristic peak of 1,4-C=C-: 5.4ppm, the proton characteristic peak of 1,2-C=C-: 5.0ppm, the proton characteristic peak of saturated hydrocarbons: 1.25ppm, the proton characteristic peak of cyano-linked: 2.5ppm, and the calculation formula of the degree of hydrogenation is as follows:

[0064] Degree of hydrogenation HD (%) = 1-unsaturation (U)

[0065] Determination of glass transition temperature Tg: DSC is used to measure the glass transition temperature of the product. The instrument model is DSC1, the company is Swiss Mettler, the temperature rise range is -80 to 80°C, and the temperature rise rate is 10°C / min.

[0066] Compression set: Execute the method in standard GB / T 7759.1-2015.

[0067] Example 1

[0068] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0069] a Preparation of macromolecular composite functional long-chain monomers: In a 10L stainless steel polymerizer with a jacket, the system was replaced three times by passing argon, 1000g cyclohexane, 300g dihydromyrcenol, 200g N-(4-hydroxybutyl)acrylamide, and 0.5g THF were added to the polymerizer in sequence, and the temperature was raised to 50°C. Then, 150mmol n-butyl lithium was added to the polymerizer to react for 70min; finally, 10g 1,3-butadiene was added to the polymerizer for end-capping, and the reaction was carried out for 30min until no free monomers were present. The colloid was wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer.

[0070] b Preparation of SB / (S→B) copolymer: In a 10L stainless steel polymerizer with a jacket, the system was replaced three times with argon, 1500g of cyclohexane and 0.5g of THF were added to the polymerizer in sequence, the temperature was raised to 60°C, 170mmol of n-butyllithium was added, and then 500g of 1,3-butadiene and 150g of styrene were stirred and mixed for 20min. The mixture was added to the polymerizer by continuous injection at an initial feeding rate of 80g of mixture / min and the feeding rate was reduced by 4g of mixture per minute. The reaction was carried out for 70min until no free monomer was present. The rubber solution was wet-coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer.

[0071] Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system three times, 1000g cyclohexane, 500g 1,3-butadiene, and 0.25g THF were added to the polymerizer in sequence, and after the temperature was raised to 40°C, 310mmol n-butyl lithium was added to start the reaction. Within 55min, the temperature was gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reached 100%, the temperature was raised to 80°C, 100mmol 1,3,5-trichlorobenzene was added, and the coupling reaction was carried out for 70min; then 100g The SB / (S→B) copolymer was mixed with 500g of cyclohexane and stirred for dissolution for 70min, and then added into a polymerization kettle for coupling reaction for 90min until it was completely dissolved. Finally, 20g of a macromolecular composite functional long-chain monomer was mixed with 500g of cyclohexane and stirred for dissolution for 60min, and then added into a polymerization kettle for coupling reaction for 70min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent (Mn was 6100, Mw / Mn was 12.13).

[0072] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0073] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 3% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed with hydrogen for 30 minutes, and then 0.02g of GrubbsⅠ catalyst xylene solution (mass concentration of 5%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 11MPa, the temperature was raised to 100℃, and after reacting for 9.0hr, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=84.1%).

[0074] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 6% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 3 times, and then 4.0g of a macromolecular three-arm star-shaped composite functionalized grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 80°C, a mixture of 0.20g BPO and 100g chlorobenzene was added. After reacting for 11.0 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 1.9%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0075] Example 2

[0076] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0077] a Preparation of macromolecular composite functional long-chain monomers: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it three times, 1100g cyclohexane, 310g dihydromyrcenol, 190g N-(4-hydroxybutyl)acrylamide, and 0.7g THF were added to the polymerizer in sequence, and the temperature was raised to 52°C. Then, 147mmol n-butyl lithium was added to the polymerizer to react for 72min; finally, 13g 1,3-butadiene was added to the polymerizer for end-capping, and the reaction was continued for 32min until no free monomers were present. The colloid was wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer.

[0078] b Preparation of SB / (S→B) copolymer: In a 10L stainless steel polymerizer with a jacket, the system was replaced three times with argon, 1600g of cyclohexane and 1.0g of THF were added to the polymerizer in sequence, the temperature was raised to 62°C, 167mmol of n-butyllithium was added, and then 500g of 1,3-butadiene and 160g of styrene were stirred and mixed for 22min. The mixture was added to the polymerizer by continuous injection at an initial feeding rate of 80g of mixture / min and the feeding rate was reduced by 4g of mixture per minute. The reaction was carried out for 72min until no free monomer was present. The rubber solution was wet-coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer.

[0079] Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it three times, and 1100g cyclohexane, 500g 1,3-butadiene, and 0.30g THF were added to the polymerizer in sequence. After the temperature was raised to 40°C, 300mmol n-butyl lithium was added to start the reaction. Within 55min, the temperature was gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reached 100%, the temperature was raised to 82°C, 95mmol 1,3,5-trichlorobenzene was added, and the coupling reaction lasted for 72min. Then 110g The SB / (S→B) copolymer was mixed with 600g of cyclohexane and stirred for dissolution for 72min, and then added into a polymerization kettle for coupling reaction for 92min until it was completely dissolved; finally, 23g of a macromolecular composite functional long-chain monomer was mixed with 550g of cyclohexane and stirred for dissolution for 62min, and then added into a polymerization kettle for coupling reaction for 72min until no free monomer was present, and the colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent (Mn was 6800, Mw / Mn was 12.52).

[0080] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0081] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0082] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 6.5% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 3 times, and then 5.0g of a macromolecular three-arm star-shaped composite functionalized grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 82°C, a mixed solution of 0.32g BPO and 110g chlorobenzene was added, and after reacting for 11.2 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.1%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0083] Example 3

[0084] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0085] a Preparation of macromolecular composite functional long-chain monomers: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it 4 times, 1200g cyclohexane, 320g dihydromyrcenol, 180g N-(4-hydroxybutyl)acrylamide, and 0.9g THF were added to the polymerizer in sequence, and the temperature was raised to 54°C. Then, 143mmol n-butyl lithium was added to the polymerizer to react for 74min; finally, 17g 1,3-butadiene was added to the polymerizer for end-capping, and the reaction was continued for 34min until no free monomers were present. The colloid was wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer.

[0086] b Preparation of SB / (S→B) copolymer: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it 4 times, 1700g of cyclohexane and 1.3g of THF were added to the polymerizer in sequence, the temperature was raised to 64°C, 163mmol of n-butyllithium was added, and then 500g of 1,3-butadiene and 170g of styrene were stirred and mixed for 24min. The mixture was added to the polymerizer by continuous injection at an initial feeding rate of 65g of mixture / min. The feeding rate was reduced by 2g of mixture per minute and the reaction was carried out for 74min until no free monomer was present. The rubber solution was wet-coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer.

[0087] Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 4 times, 1200g cyclohexane, 500g 1,3-butadiene, and 0.35g THF were added to the polymerizer in sequence, and after the temperature was raised to 40°C, 300mmol n-butyl lithium was added to start the reaction. Within 60min, the temperature was gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reached 100%, the temperature was raised to 84°C, 90mmol 1,3,5-trichlorobenzene was added, and the coupling reaction lasted for 74min; then 120g The SB / (S→B) copolymer was mixed with 700 g of cyclohexane and stirred for dissolution for 74 min, and then added into a polymerization kettle for coupling reaction for 94 min until it was completely dissolved. Finally, 26 g of a macromolecular composite functional long-chain monomer was mixed with 600 g of cyclohexane and stirred for dissolution for 64 min, and then added into a polymerization kettle for coupling reaction for 74 min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent (Mn was 7300, Mw / Mn was 12.86).

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

[0089] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0090] b. Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 7.6% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 4 times, and then 5.5g of a macromolecular three-arm star-shaped composite functionalized grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 84°C, a mixture of 0.43g BPO and 140g chlorobenzene was added, and after reacting for 11.4 hours, anhydrous ethanol was used for flocculation, washing, and drying in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.3%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0091] Example 4

[0092] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0093] a Preparation of macromolecular composite functional long-chain monomers: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it 4 times, 1300g cyclohexane, 330g dihydromyrcenol, 170g N-(4-hydroxybutyl) acrylamide, and 1.1g THF were added to the polymerizer in sequence, and the temperature was raised to 56°C. Then, 140mmol n-butyl lithium was added to the polymerizer to react for 76min; finally, 20g 1,3-butadiene was added to the polymerizer for end-capping, and the reaction was continued for 36min until no free monomers were present. The colloid was wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer.

[0094] b Preparation of SB / (S→B) copolymer: In a 10L stainless steel polymerizer with a jacket, the system was replaced 4 times by passing argon, 1800g of cyclohexane and 1.6g of THF were added to the polymerizer in sequence, the temperature was raised to 66°C, 158mmol of n-butyllithium was added, and then 500g of 1,3-butadiene and 180g of styrene were stirred and mixed for 26min. The mixture was added to the polymerizer by continuous injection at an initial feeding rate of 65g of mixture / min. The feeding rate was reduced by 2g of mixture per minute and the reaction was carried out for 76min until no free monomer was present. The rubber solution was wet-coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer.

[0095] Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 4 times, 1300g cyclohexane, 500g 1,3-butadiene, and 0.40g THF were added to the polymerizer in sequence, and after the temperature was raised to 40°C, 292mmol n-butyl lithium was added to start the reaction. Within 63min, the temperature was gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reached 100%, the temperature was raised to 86°C, 85mmol 1,3,5-trichlorobenzene was added, and the coupling reaction lasted for 76min; then 130g The SB / (S→B) copolymer was mixed with 800g of cyclohexane and stirred for dissolution for 76min, and then added into a polymerization kettle for coupling reaction for 96min until it was completely dissolved. Finally, 29g of a macromolecular composite functional long-chain monomer was mixed with 650g of cyclohexane and stirred for dissolution for 66min, and then added into a polymerization kettle for coupling reaction for 76min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent (Mn was 7900, Mw / Mn was 13.15).

[0096] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0097] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 4.5% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed with hydrogen for 36 minutes, and then 0.07g of GrubbsⅠ catalyst xylene solution (mass concentration was 8%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 12MPa, and the temperature was raised to 113°C. After reacting for 10 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=87.1%).

[0098] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.2%, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 4 times, and then 6.0g of a macromolecular three-arm star-shaped composite functionalized grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 86°C, a mixed solution of 0.48g BPO and 160g chlorobenzene was added, and after reacting for 11.6 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.5%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0099] Example 5

[0100] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0101] a Preparation of macromolecular composite functional long-chain monomers: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 5 times, 1400g cyclohexane, 340g dihydromyrcenol, 160g N-(4-hydroxybutyl) acrylamide, and 1.3g THF were added to the polymerizer in sequence, and the temperature was raised to 58°C. Then, 145mmol n-butyl lithium was added to the polymerizer to react for 78min; finally, 23g 1,3-butadiene was added to the polymerizer for end-capping, and the reaction was continued for 38min until no free monomers were present. The colloid was wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer.

[0102] b Preparation of SB / (S→B) copolymer: In a 10L stainless steel polymerizer with a jacket, the system was replaced 5 times by passing argon, 1900g of cyclohexane and 1.8g of THF were added to the polymerizer in sequence, the temperature was raised to 68°C, 152mmol of n-butyllithium was added, and then 500g of 1,3-butadiene and 190g of styrene were stirred and mixed for 28min. The mixture was added to the polymerizer by continuous injection at an initial feeding rate of 65g of mixture / min. The feeding rate was reduced by 2g of mixture per minute and the reaction was carried out for 78min until no free monomer was present. The rubber solution was wet coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer.

[0103] Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 5 times, 1400g cyclohexane, 500g 1,3-butadiene, and 0.45g THF were added to the polymerizer in sequence, and after the temperature was raised to 40°C, 285mmol n-butyl lithium was added to start the reaction. Within 66min, the temperature was gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reached 100%, the temperature was raised to 88°C, 80mmol 1,3,5-trichlorobenzene was added, and the coupling reaction lasted for 78min; then 140g The SB / (S→B) copolymer was mixed with 900 g of cyclohexane and stirred for 78 min until it was completely dissolved, and then added to a polymerization kettle for coupling reaction for 98 min. Finally, 32 g of a macromolecular composite functional long-chain monomer was mixed with 700 g of cyclohexane and stirred for 68 min until it was completely dissolved, and then added to a polymerization kettle for coupling reaction for 78 min until no free monomer was present. The gel was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent (Mn was 8400, Mw / Mn was 13.57).

[0104] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0105] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0106] b. Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.7%, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 5 times, and then 7.2g of a macromolecular three-arm star-shaped composite functionalized grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 88°C, a mixed solution of 0.53g BPO and 180g chlorobenzene was added, and after reacting for 11.8 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.6%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0107] Example 6

[0108] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0109] a Preparation of macromolecular composite functional long-chain monomers: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 5 times, 1500g cyclohexane, 350g dihydromyrcenol, 150g N-(4-hydroxybutyl)acrylamide, and 1.5g THF were added to the polymerizer in sequence, and the temperature was raised to 60°C. Then, 132mmol n-butyl lithium was added to the polymerizer to react for 80min; finally, 25g 1,3-butadiene was added to the polymerizer for end-capping, and the reaction was carried out for 40min until no free monomers were present. The colloid was wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer.

[0110] b Preparation of SB / (S→B) copolymer: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it 5 times, 2000g cyclohexane and 2.0g THF were added to the polymerizer in sequence, the temperature was raised to 70°C, 149mmol n-butyllithium was added, and then 500g 1,3-butadiene and 200g styrene were stirred and mixed for 30min. The mixture was added to the polymerizer by continuous injection at an initial feeding rate of 65g mixture / min. The feeding rate was reduced by 2g mixture per minute and the reaction was carried out for 80min until no free monomer was present. The rubber solution was wet coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer.

[0111] Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 5 times, 1500g cyclohexane, 500g 1,3-butadiene, and 0.50g THF were added to the polymerizer in sequence, and after the temperature was raised to 40°C, 279mmol n-butyl lithium was added to start the reaction. Within 70min, the temperature was gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reached 100%, the temperature was raised to 90°C, 75mmol 1,3,5-trichlorobenzene was added, and the coupling reaction was carried out for 80min; then 150g The SB / (S→B) copolymer was mixed with 1000g of cyclohexane and stirred for 80min until it was completely dissolved, and then added to a polymerization kettle for coupling reaction for 100min. Finally, 35g of a macromolecular composite functional long-chain monomer was mixed with 700g of cyclohexane and stirred for 70min until it was completely dissolved, and then added to a polymerization kettle for coupling reaction for 80min until no free monomer was present. The gel was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent (Mn was 9000, Mw / Mn was 13.94).

[0112] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0113] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0114] b. Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: First, 200g of HNBR rubber was dissolved in chlorobenzene solution to prepare a 9.0% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 5 times, and then 8.0g of a macromolecular three-arm star-shaped composite functionalized grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 90°C, a mixed solution of 0.60g of BPO and 200g of chlorobenzene was added. After reacting for 12.0 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.7%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0115] Comparative Example 1

[0116] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0117] a. Preparation of macromolecular composite functionalized long-chain monomer: same as Example 1.

[0118] b Preparation of SB / (S→B) copolymer: Other conditions were the same as those in Example 1, except that variable speed polymerization was not used in the preparation of SB / (S→B) copolymer, i.e., in a 10 L stainless steel polymerizer with a jacket, the system was replaced three times by passing argon gas, 1500 g of cyclohexane and 0.5 g of THF were added to the polymerizer in sequence, the temperature was raised to 60°C, 170 mmol of n-butyl lithium was added, and then 500 g of 1,3-butadiene and 150 g of styrene were stirred and mixed for 20 min, and then added to the polymerizer together to react for 70 min until no free monomer was present. The rubber solution was wet coagulated and dried to obtain SBR copolymer.

[0119] c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: Other conditions are the same as those in Example 1, except that SB / (S→B) copolymer is not added during the preparation of the macromolecular three-arm star-shaped composite functionalized grafting agent, but SBR copolymer is added in an amount of 100 g, that is: in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace the system 3 times, 1000 g cyclohexane, 500 g 1,3-butadiene, and 0.25 g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 40°C, 310 mmol n-butyl lithium is added to start the reaction, and within 55 min, the temperature is gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution, and after the conversion rate of 1,3-butadiene monomer reaches 100%; the temperature is raised to 80°C, 100 mmol 1,3,5-trichlorobenzene is added, and the coupling reaction is carried out for 70 min; then 100 g The SBR copolymer and 500g of cyclohexane were mixed and stirred for 70 minutes to dissolve, and then added to a polymerization kettle for coupling reaction for 90 minutes until they were completely dissolved; finally, 20g of a macromolecular composite functional long-chain monomer was mixed with 500g of cyclohexane and stirred for 60 minutes to dissolve, and then added to a polymerization kettle for coupling reaction for 70 minutes until no free monomers were present. The glue was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent a (Mn was 5900, Mw / Mn was 8.24).

[0120] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0121] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0122] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 1, except that in the preparation process of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, no macromolecular three-arm star-shaped composite functionalized grafting agent is added, but a macromolecular three-arm star-shaped composite functionalized grafting agent a is added, and the addition amount is 4.0 g, that is: first, 200 g HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 6%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 3 times, and then 4.0 g of macromolecular three-arm star-shaped composite functionalized grafting agent a is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 80°C, 0.20 g of The mixture of BPO and 100g chlorobenzene was reacted for 11.0 hours, flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 1.7%). Sampling analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0123] Comparative Example 2

[0124] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0125] a. Preparation of macromolecular composite functionalized long-chain monomer: same as Example 2.

[0126] b. Preparation of SB / (S→B) copolymer: Other conditions were the same as those in Example 2, except that the rate of addition of 1,3-butadiene and styrene mixture was reduced by 1 g per minute during the preparation of SB / (S→B) copolymer, i.e., in a 10 L stainless steel polymerizer with a jacket, the system was replaced three times by argon, 1600 g of cyclohexane and 1.0 g of THF were added to the polymerizer in sequence, the temperature was raised to 62° C., 167 mmol of n-butyl lithium was added, 500 g of 1,3-butadiene and 160 g of styrene were stirred and mixed for 22 min, and then the mixture was added to the polymerizer in a continuous injection manner at an initial rate of 80 g of mixture / min and the rate of addition was reduced by 1 g per minute, and the mixture was reacted for 72 min until no free monomer was present. The rubber solution was wet coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer a.

[0127] c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: Other conditions are the same as those in Example 2, except that SB / (S→B) copolymer is not added during the preparation of the macromolecular three-arm star-shaped composite functionalized grafting agent, but SB / (S→B) copolymer a is added in an amount of 110 g, that is: in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace the system 3 times, 1100 g cyclohexane, 500 g 1,3-butadiene, and 0.30 g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 40°C, 300 mmol n-butyl lithium is added to start the reaction, and within 55 minutes, the temperature is gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution, and after the conversion rate of 1,3-butadiene monomer reaches 100%; the temperature is raised to 82°C, 95 mmol 1,3,5-trichlorobenzene is added, and the coupling reaction is carried out for 72 minutes; then 110 g SB / (S→B) copolymer a was mixed with 600g cyclohexane and stirred for 72min to dissolve until it was completely dissolved, and then added to a polymerization kettle for coupling reaction for 92min; finally, 23g of a macromolecular composite functional long-chain monomer was mixed with 550g cyclohexane and stirred for 62min to dissolve until it was completely dissolved, and then added to a polymerization kettle for coupling reaction for 72min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent b (Mn was 6300, Mw / Mn was 10.46).

[0128] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0129] a Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 2.

[0130] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 2, except that in the preparation process of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, no macromolecular three-arm star-shaped composite functionalized grafting agent is added, but a macromolecular three-arm star-shaped composite functionalized grafting agent b is added, and the addition amount is 5.0 g, that is: first, 200 g HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 6.5%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 3 times, and then 5.0 g of macromolecular three-arm star-shaped composite functionalized grafting agent b is added to the reactor, stirred, mixed, and heated, and when the temperature of the reactor reaches 82°C, 0.32 g of The mixture of BPO and 110g chlorobenzene was reacted for 11.2 hours, flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 1.8%). Sampling analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0131] Comparative Example 3

[0132] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0133] a. Preparation of macromolecular composite functionalized long-chain monomer: same as Example 3.

[0134] b Preparation of SB / (S→B) copolymer: same as Example 3.

[0135] c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: Other conditions are the same as those in Example 3, except that the BR segment is not polymerized at variable temperature during the preparation of the macromolecular three-arm star-shaped composite functionalized grafting agent, that is: in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace it 4 times, 1200g cyclohexane, 500g 1,3-butadiene, and 0.35g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 40°C, 300mmol n-butyl lithium is added to start the reaction for 60min to form a BR segment, and after the conversion rate of 1,3-butadiene monomer reaches 100%; the temperature is raised to 84°C, 90mmol 1,3,5-trichlorobenzene is added, and the coupling reaction is carried out for 74min; then 120g The SB / (S→B) copolymer was mixed with 700 g of cyclohexane and stirred for dissolution for 74 min, and then added into a polymerization kettle for coupling reaction for 94 min until it was completely dissolved. Finally, 26 g of a macromolecular composite functional long-chain monomer was mixed with 600 g of cyclohexane and stirred for dissolution for 64 min, and then added into a polymerization kettle for coupling reaction for 74 min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functional grafting agent c (Mn was 7100, Mw / Mn was 9.86).

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

[0137] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 3.

[0138] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 3, except that in the preparation process of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, no macromolecular three-arm star-shaped composite functionalized grafting agent is added, but a macromolecular three-arm star-shaped composite functionalized grafting agent c is added, and the addition amount is 5.5 g, that is: first, 200 g HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 7.6%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 4 times, and then 5.5 g of macromolecular three-arm star-shaped composite functionalized grafting agent c is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 84°C, 0.43 g of The mixture of BPO and 140g chlorobenzene was reacted for 11.4 hours, flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.1%). Sampling analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0139] Comparative Example 4

[0140] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0141] a. Preparation of macromolecular composite functionalized long-chain monomer: same as Example 4.

[0142] b Preparation of SB / (S→B) copolymer: same as Example 4.

[0143] c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: Other conditions are the same as those in Example 4, except that 1,3,5-trichlorobenzene is not added during the preparation of the macromolecular three-arm star-shaped composite functionalized grafting agent, that is: in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace 4 times, 1300g cyclohexane, 500g 1,3-butadiene, and 0.40g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 40°C, 292mmol n-butyl lithium is added to start the reaction. Within 63min, the temperature is gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reaches 100%, the temperature is raised to 86°C, and then 130g The SB / (S→B) copolymer was mixed with 800 g of cyclohexane and stirred for dissolution for 76 min, and then added into a polymerization kettle for coupling reaction for 96 min until it was completely dissolved. Finally, 29 g of a macromolecular composite functionalized long-chain monomer was mixed with 650 g of cyclohexane and stirred for dissolution for 66 min, and then added into a polymerization kettle for coupling reaction for 76 min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functionalized grafting agent d (Mn was 5600, Mw / Mn was 8.49).

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

[0145] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0146] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 4, except that in the preparation process of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, no macromolecular three-arm star-shaped composite functionalized grafting agent is added, but a macromolecular three-arm star-shaped composite functionalized grafting agent d is added, and the addition amount is 6.0 g, that is: first, 200 g of HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.2%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 4 times, and then 6.0 g of macromolecular three-arm star-shaped composite functionalized grafting agent d is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 86°C, 0.48 g of The mixture of BPO and 160g chlorobenzene was reacted for 11.6 hours, flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 1.6%). Sampling analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0147] Comparative Example 5

[0148] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0149] a. Preparation of macromolecular composite functionalized long-chain monomer: same as Example 5.

[0150] b Preparation of SB / (S→B) copolymer: same as Example 5.

[0151] c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: Other conditions are the same as those in Example 5, except that the amount of 1,3,5-trichlorobenzene added during the preparation of the macromolecular three-arm star-shaped composite functionalized grafting agent is 300 mmol, that is: in a 10L stainless steel polymerization kettle with a jacket, the system is replaced 5 times by argon, 1400 g of cyclohexane, 500 g of 1,3-butadiene, and 0.45 g of THF are added to the polymerization kettle in sequence, and after the temperature is raised to 40°C, 285 mmol of n-butyl lithium is added to start the reaction. Within 66 minutes, the temperature is gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reaches 100%, the temperature is raised to 88°C, 300 mmol of 1,3,5-trichlorobenzene is added, and the coupling reaction is carried out for 78 minutes; then 140 g of The SB / (S→B) copolymer was mixed with 900 g of cyclohexane and stirred for dissolution for 78 min, and then added into a polymerization kettle for coupling reaction for 98 min until it was completely dissolved. Finally, 32 g of a macromolecular composite functionalized long-chain monomer was mixed with 700 g of cyclohexane and stirred for dissolution for 68 min, and then added into a polymerization kettle for coupling reaction for 78 min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functionalized grafting agent e (Mn was 7600, Mw / Mn was 11.26).

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

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

[0154] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 5, except that in the preparation process of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, no macromolecular three-arm star-shaped composite functionalized grafting agent is added, but a macromolecular three-arm star-shaped composite functionalized grafting agent e is added, and the addition amount is 7.2g, that is: first, 200g HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.7%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 5 times, and then 7.2g of macromolecular three-arm star-shaped composite functionalized grafting agent e is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 88°C, 0.53g of The mixture of BPO and 180g chlorobenzene was reacted for 11.8 hours, flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.2%). Sampling analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0155] Comparative Example 6

[0156] (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent:

[0157] a. Preparation of macromolecular composite functionalized long-chain monomer: same as Example 6.

[0158] b Preparation of SB / (S→B) copolymer: omitted.

[0159] c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: Other conditions were the same as those in Example 6, except that SB / (S→B) copolymer was not added during the preparation of the macromolecular three-arm star-shaped composite functionalized grafting agent, namely: in a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace the system 5 times, 1500g cyclohexane, 500g 1,3-butadiene, and 0.50g THF were added to the polymerization kettle in sequence, and after the temperature was raised to 40°C, 279mmol n-butyl lithium was added to start the reaction, and within 70min, the temperature was gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution, and after the 1,3-butadiene monomer conversion rate reached 100%; the temperature was raised to 90°C, 75mmol n-butyl lithium was added, and the reaction mixture was stirred for 2 hours. 1,3,5-trichlorobenzene, coupling reaction for 80 minutes; then 35g of the macromolecular composite functional long-chain monomer was mixed with 700g of cyclohexane and stirred for 70 minutes until it was completely dissolved and then added into the polymerization kettle for coupling reaction for 80 minutes until there was no free monomer. The gel was wet-coagulated and dried to obtain a macromolecular two-arm star-shaped composite functional grafting agent (Mn was 4800, Mw / Mn was 7.15).

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

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

[0162] b Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 6, except that in the preparation process of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, a macromolecular three-arm star-shaped composite functionalized grafting agent is not added, but a macromolecular two-arm star-shaped composite functionalized grafting agent is added, and the amount added is 8.0 g, that is, firstly, 200 g of HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 9.0%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 5 times, and then 8.0 g of a macromolecular two-arm star-shaped composite functionalized grafting agent is added to the reactor, stirred, mixed, and heated, and when the temperature of the reactor reaches 90°C, 0.60 g of The mixture of BPO and 200g chlorobenzene was reacted for 12.0 hours, flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields (grafting rate 1.8%). Sampling analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0163] Table 1 Properties of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields

[0164]

[0165]

[0166] It can be seen from Table 1 that the compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields of the present invention has a small compression permanent deformation and a low glass transition temperature, and is suitable for oil well operations under the working conditions of compression permanent deformation ≤ 11% and an ambient temperature of -74°C.

[0167] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, characterized in that: The steps include: (1) Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: a. Preparation of macromolecular composite functional long-chain monomers: In a polymerization kettle, argon is introduced to replace the system, and a solvent, dihydromyrcenol, N-(4-hydroxybutyl)acrylamide, and a structure regulator are added to the polymerization kettle in sequence, and the temperature is raised, and then initiator 1 is added to the polymerization kettle for reaction; finally, 1,3-butadiene is added to the polymerization kettle for end-capping, and the reaction is continued until no free monomers are present, and the colloid is wet-coagulated and dried to obtain a macromolecular composite functional long-chain monomer; b Preparation of SB / (S→B) copolymer: In a polymerization kettle, argon gas is introduced to replace the system, and a solvent and a structure regulator are added to the polymerization kettle in sequence, the temperature is raised, and an initiator 1 is added. Subsequently, 1,3-butadiene and styrene are stirred and mixed, and then added to the polymerization kettle to react until no free monomer is present. The colloid is wet-coagulated and dried to obtain a random, long gradient SB / (S→B) copolymer; c Preparation of macromolecular three-arm star-shaped composite functionalized grafting agent: In a polymerization kettle, argon is introduced to replace the system, and solvent 1, 1,3-butadiene, and a structure regulator are added to the polymerization kettle in sequence, the temperature is raised, and initiator 1 is added. The reaction is a temperature-variable polymerization. Within 50 to 70 minutes, the temperature is gradually raised from 40°C to 70°C to form a BR segment with a wide vinyl distribution. After the conversion rate of 1,3-butadiene monomer reaches 100%, the temperature is raised and a coupling agent is added to carry out a coupling reaction; then the SB / (S→B) copolymer and the solution are mixed and stirred to dissolve, and then the mixture is added to the polymerization kettle for a coupling reaction until it is completely dissolved; finally, the macromolecular composite functionalized long-chain monomer is mixed with solvent 2 and stirred to dissolve, and then the mixture is added to the polymerization kettle for a coupling reaction until no free monomer exists. The glue solution is wet-coagulated and dried to obtain a macromolecular three-arm star-shaped composite functionalized grafting agent; (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: a Preparation of hydrogenated nitrile rubber (HNBR): dissolve nitrile rubber in chlorobenzene solution to prepare a rubber solution, then add the rubber solution into a reactor and introduce inert gas to remove the air in the reactor, then remove the inert gas in the reactor with hydrogen, add a xylene solution of Grubbs I catalyst under nitrogen protection, pressurize, heat, react, cool the system, condense, and vacuum dry to obtain HNBR rubber; b. Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution, and then the glue solution is added to a reactor, and an inert gas is introduced for replacement, and then a macromolecular three-arm star-shaped composite functionalized grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of initiator 2 and chlorobenzene is added, reacted, flocculated, washed, and dried to obtain compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields; The macromolecular three-arm star-shaped composite functionalized grafting agent has the following structure: Among them, BR is a 1,3-butadiene homopolymer segment with a wide vinyl distribution; SB is a random segment of styrene and 1,3-butadiene; (S→B) is a gradient segment of styrene and 1,3-butadiene; B is a terminal 1,3-butadiene; n, m, L are positive integers of the number of repeating units, n≥1, m≥1, L≥1; the number average molecular weight (Mn) of the macromolecular three-arm star-shaped composite functionalized grafting agent is 6000-9000, and the molecular weight distribution (Mw / Mn) is 12.13-13.

94.

2. The preparation method according to claim 1, characterized in that: The initiator 1 is selected from one of n-butyl lithium, sec-butyl lithium, methylbutyl lithium, phenylbutyl lithium, naphthalene lithium, cyclohexyl lithium and dodecyl lithium.

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, dicumyl peroxide (DCP) and dibenzoyl peroxide (BPO), and its addition amount is 0.1 to 0.3 parts based on 100 parts of the mass of the HNBR rubber.

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

5. The preparation method according to claim 1, characterized in that: The coupling agent is one of 1,3,5-trichlorobenzene and 1,3,5-tribromobenzene.

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

7. The preparation method according to claim 1, characterized in that: The solvent, solvent 1, solvent 2 or solution is selected from one of cyclohexane, 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 ratio of the solvent, dihydromyrcenol, N-(4-hydroxybutyl)acrylamide, structure regulator and 1,3-butadiene is 200-300:60-70, 30-40:0.1-0.3:2-5.

9. The preparation method according to claim 1, characterized in that: In step (1) b, the mass ratio of the solvent, the structure regulator, 1,3-butadiene and styrene is 300-400: 0.1-0.4: 100: 30-40.

10. The preparation method according to claim 1, characterized in that: In step (1) c, the mass ratio of the solvent 1, 1,3-butadiene, structure regulator, SB / (S→B) copolymer, solution, macromolecular composite functionalized long-chain monomer, and solvent 2 is 200-300:100:0.05-0.1:20-30:100-200:4-7:100-150.

11. 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.

12. 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%.

13. The preparation method according to claim 1, characterized in that: In step (2) b, the mass ratio of the HNBR rubber, the macromolecular three-arm star-shaped composite functionalized grafting agent, and chlorobenzene is 100:2-4:50-100.

14. The preparation method according to claim 1, characterized in that: In step (2) b, the grafting rate of the compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields is 1.9% to 2.7%.

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

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