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 composite functional macromolecular long-branch chain grafting agent; and (2) preparing the compression-resistant and cold-resistant hydrogenated butadiene-acrylonitrile rubber for the oil field. The compound functional macromolecular long branch chain grafting agent has the following structure: # imgabs0 #, wherein IR is an isoprene 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 butadiene; b is terminated 1, 3-butadiene, n is the number of repetitive units, and n is a positive integer greater than or equal to 1; the number-average molecular weight (Mn) of the composite functionalized macromolecular long branch chain grafting agent is 6000-8000, and the molecular weight distribution (Mw / Mn) of the composite functionalized macromolecular long branch chain grafting agent is 9.13-10.86. The preparation method of the compression-resistant and cold-resistant hydrogenated butadiene-acrylonitrile rubber for the oil field has the characteristics of environment friendliness, efficient modification effect, low dosage of a modifier, 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 in particular relates to a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields modified by a composite functional macromolecular long-branch 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 part 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 part of the epoxy groups with acid anhydride under the action of a catalyst to introduce ester groups, thereby obtaining a special hydrogenated nitrile rubber containing epoxy groups and ester groups. N 105294939B 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, the present invention provides a method for preparing a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields, which has a compression permanent deformation resistance of ≤16% and a glass transition temperature Tg<-71°C and can meet the use requirements within the range of -71°C to -74°C. The invention firstly uses dihydromyrcenol and N-(4-hydroxybutyl) acrylamide to prepare a composite functional macromolecular long-chain monomer through anionic polymerization; secondly, using anionic polymerization method, the reaction monomers are isoprene, styrene, 1,3-butadiene and composite functional macromolecular long-chain monomers, and a composite functional macromolecular long-chain branching grafting agent with free radical reaction activity containing a wide vinyl distribution and a random gradient segment is prepared through variable temperature polymerization and variable speed polymerization; finally, the composite functional macromolecular long-chain branching grafting agent is grafted onto the main chain of hydrogenated nitrile rubber to prepare a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields. This method not only solves the problem of easy crystallization of hydrogenated nitrile rubber, but also greatly improves the viscoelasticity of hydrogenated nitrile rubber, so that hydrogenated nitrile rubber shows 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 composite functionalized macromolecular long-branched grafting agent:

[0011] a Preparation of composite functional macromolecular long-chain monomers: In a polymerization kettle, argon gas is introduced to replace the system, and a solvent, dihydromyrcenol, N-(4-hydroxybutyl)acrylamide, and a structure regulator are sequentially added to the polymerization kettle, 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 carried out until no free monomers are present, and the glue solution is wet-coagulated and dried to obtain a composite functional macromolecular 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 composite functional macromolecular long-chain branching grafting agent: In a polymerization kettle, argon gas is introduced to replace the system, and a solvent, isoprene, and a first structural regulator are added to the polymerization kettle in sequence, the temperature is raised, and initiator 1 is added. The reaction is a variable temperature polymerization. Within 60 to 70 minutes, the temperature gradually rises from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then the SB / (S→B) copolymer and the composite functional macromolecular long-chain monomer are mixed with the solution and stirred to dissolve until they are completely dissolved, and then added to the polymerization kettle together with the second structural regulator for reaction; finally, 1,3-butadiene is added to the polymerization kettle for end-capping, and the reaction is carried out until no free monomer exists. The glue solution is wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching 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): dissolving nitrile rubber in chlorobenzene solution to prepare a rubber solution, then adding the rubber solution into a reactor and introducing an inert gas to remove the air in the reactor, then removing the inert gas in the reactor with hydrogen, adding a xylene solution of Grubbs I catalyst under nitrogen protection, pressurizing, heating, reacting, cooling the system, condensing, and drying 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 composite functional macromolecular long-branched 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 composite functionalized macromolecular long-branched grafting agent has the following structure:

[0018]

[0019] Among them, IR is an isoprene 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 butadiene; B is a terminal 1,3-butadiene, n is the number of repeating units, and n is a positive integer of ≥1; the number average molecular weight (Mn) of the composite functionalized macromolecular long-branched grafting agent is 6000-8000, and the molecular weight distribution (Mw / Mn) is 9.13-10.86.

[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 0.05-0.15 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 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).

[0024] The solvent or solution of the present invention can be selected from one of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene and xylene, preferably cyclohexane.

[0025] 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.

[0026] In step (1) a of the present invention, the temperature is raised to 50-60°C.

[0027] In step (1) a of the present invention, the reaction time after adding the initiator 1 is 70 to 80 minutes.

[0028] In step (1) a of the present invention, the reaction time for adding 1,3-butadiene for end-capping 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 a reaction temperature of 60 to 70°C.

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

[0032] In step (1) c of the present invention, the mass ratio of the solvent, isoprene, the first structural regulator, the SB / (S→B) copolymer and the composite functionalized macromolecular long-chain monomer, the solution, the second structural regulator, and 1,3-butadiene is 200%-300:100:0.05-0.2:30-40:5-10:300-400:0.2-0.5:2-5.

[0033] In step (1) of the present invention, the stirring and dissolving time is 50 to 60 minutes.

[0034] In step (1) c of the present invention, the reaction time after adding the second structure regulator is 90 to 100 minutes, and the reaction time after adding 1,3-butadiene for end-capping is 20 to 30 minutes.

[0035] 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.

[0036] In step (2) a of the present invention, the mass fraction of nitrile rubber in the rubber solution is 3% to 6%.

[0037] 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%.

[0038] 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.

[0039] In step (2) a of the present invention, the degree of hydrogenation HD of the HNBR rubber is less than 90%.

[0040] In step (2) b of the present invention, the mass ratio of the HNBR rubber, the composite functionalized macromolecular long-chain branching grafting agent, and chlorobenzene is 100:2-8:50-100.

[0041] In step (2) b of the present invention, the mass fraction of HNBR rubber in the rubber solution is 6% to 9%.

[0042] In step (2) b of the present invention, the reaction temperature is 80-90° C. and the reaction time is 8.0-10.0 hr.

[0043] 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 2.2% to 3.1%.

[0044] 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.

[0045] The reactor described in the present invention can be a loop reactor or a tank reactor, preferably a tank reactor.

[0046] 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.

[0047] The present invention also provides a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields obtained by the preparation method.

[0048] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0049] (1) The SB / (S→B) copolymer prepared by the present invention is mainly prepared by using an anionic polymerization method to prepare a random and segmented SB / (S→B) copolymer by variable speed polymerization of the reaction monomers 1,3-butadiene and styrene. This copolymer utilizes the "structural effect" of the randomness of SB and the gradual change of the (S→B) long chain segment and the "aggregation effect" of the macromolecules to significantly broaden the molecular weight distribution of HNBR, which can significantly improve the viscoelasticity of HNBR. At the same time, it achieves a good "synergistic effect" with the wide distribution of the unsaturated "carbon-carbon" double bonds of IR in improving the viscoelasticity of HNBR, greatly reducing the compression permanent deformation resistance of HNBR, and can prepare a compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields with a compression permanent deformation of ≤16%.

[0050] (2) The composite functional macromolecular 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, and can effectively destroy the crystallinity of HNBR and effectively reduce the glass transition temperature (Tg) of HNBR. It can prepare compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields with a glass transition temperature Tg of raw rubber <-71°C, which is suitable for oil well operations under low temperature conditions of -71°C.

[0051] (3) The composite functional macromolecular long-branched 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.

[0052] (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

[0053] 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.

[0054] (1) Source of raw materials:

[0055]

[0056] (2) Analytical testing methods:

[0057] 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:

[0058]

[0059] 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).

[0060] 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 .

[0061] 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:

[0062] Degree of hydrogenation HD (%) = 1-unsaturation (U)

[0063] 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.

[0064] Compression set: Execute the method in standard GB / T 7759.1-2015.

[0065] Example 1

[0066] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0067] a Preparation of composite functional macromolecular long-chain monomers: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace it three times, 1000g cyclohexane, 300g dihydromyrcenol, 200g N-(4-hydroxybutyl)acrylamide, and 0.5g THF were added to the polymerization kettle in sequence, and the temperature was raised to 50°C. Then, 150mmol n-butyl lithium was added to the polymerization kettle to react for 70min; finally, 10g 1,3-butadiene was added to the polymerization kettle 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 composite functional macromolecular long-chain monomer.

[0068] 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 in a continuous manner at an initial feeding rate of 70g of mixture / min. The feeding rate was reduced by 3g of mixture per minute and 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.

[0069] Preparation of composite functional macromolecular long-chain branching agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace it three times, and 1000g cyclohexane, 500g isoprene, and 0.25g THF were added to the polymerization kettle in sequence. After the temperature was raised to 50°C, 93mmol n-butyl lithium was added to start the reaction. Within 60min, the temperature was gradually raised from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then 150g SB / (S→B) copolymer and 25g composite functional macromolecular long-chain monomer were mixed with 1500g cyclohexane and stirred to dissolve for 50min, and then added to the polymerization kettle together with 1.0g THF to react for 90min; finally, 10.0g The 1,3-butadiene was capped and the reaction was carried out for 20 minutes until no free monomer was present. The colloid was coagulated and dried by a wet method to obtain a composite functional macromolecular long-branched grafting agent (Mn was 6000, Mw / Mn was 9.13).

[0070] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0071] 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%).

[0072] 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 composite functional macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 80°C, a mixed solution of 0.10g BPO and 100g chlorobenzene was added, and after reacting for 8.0 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 2.2%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0073] Example 2

[0074] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0075] a Preparation of composite functional macromolecular 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 composite functional macromolecular long-chain monomer.

[0076] 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 70g of mixture / min and the feeding rate was reduced by 3g 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.

[0077] Preparation of composite functional macromolecular long-chain branching agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace it three times, and 1100g cyclohexane, 500g isoprene, and 0.45g THF were added to the polymerization kettle in sequence. After the temperature was raised to 50°C, 85mmol n-butyl lithium was added to start the reaction. Within 62min, the temperature gradually increased from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then 160g SB / (S→B) copolymer and 30g composite functional macromolecular long-chain monomer were mixed with 1600g cyclohexane and stirred to dissolve for 52min, until they were completely dissolved, and then added to the polymerization kettle together with 1.5g THF to react for 92min; finally, 13.0g The 1,3-butadiene was capped and the reaction was carried out for 22 minutes until no free monomer was present. The colloid was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent (Mn was 6600, Mw / Mn was 9.54).

[0078] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0079] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0080] 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 6.0g of composite functional macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 82°C, a mixture of 0.15g BPO and 120g chlorobenzene was added. After reacting for 8.5 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 2.3%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0081] Example 3

[0082] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0083] a Preparation of composite functional macromolecular 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 composite functional macromolecular long-chain monomer.

[0084] 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.

[0085] Preparation of composite functional macromolecular long-chain branching agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace it 4 times, and 1200g cyclohexane, 500g isoprene, and 0.55g THF were added to the polymerization kettle in sequence. After the temperature was raised to 50°C, 80mmol n-butyl lithium was added to start the reaction. Within 64min, the temperature gradually increased from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then 170g SB / (S→B) copolymer and 35g composite functional macromolecular long-chain monomer were mixed with 1700g cyclohexane and stirred to dissolve for 54min, until they were completely dissolved, they were added to the polymerization kettle together with 1.7g THF and reacted for 94min; finally, 18.0g The 1,3-butadiene was capped and the reaction was carried out for 24 minutes until no free monomer was present. The colloid was coagulated and dried by a wet method to obtain a composite functional macromolecular long-branched grafting agent (Mn was 7100, Mw / Mn was 9.78).

[0086] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0087] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0088] 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 9.0g of composite functional macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 84°C, a mixture of 0.20g BPO and 140g chlorobenzene was added. After reacting for 9.0 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 2.5%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0089] Example 4

[0090] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0091] a Preparation of composite functional macromolecular 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 carried out for 36min until no free monomers were present. The colloid was wet-coagulated and dried to obtain a composite functional macromolecular long-chain monomer.

[0092] 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.

[0093] Preparation of composite functional macromolecular long-chain branching agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace it 4 times, and 1300g cyclohexane, 500g isoprene, and 0.75g THF were added to the polymerization kettle in sequence. After the temperature was raised to 50°C, 76mmol n-butyl lithium was added to start the reaction. Within 66min, the temperature gradually increased from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then 180g SB / (S→B) copolymer and 40g composite functional macromolecular long-chain monomer were mixed with 1800g cyclohexane and stirred to dissolve for 56min, until they were completely dissolved, and then added to the polymerization kettle together with 2.0g THF to react for 96min; finally, 20.0g The 1,3-butadiene was capped and the reaction was carried out for 26 minutes until no free monomer was present. The colloid was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent (Mn was 7500, Mw / Mn was 10.13).

[0094] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0095] 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%).

[0096] 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 8.1%, 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 11.0g of composite functional macromolecular long-branched 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 0.23g BPO and 160g chlorobenzene was added. After reacting for 9.2 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 2.7%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0097] Example 5

[0098] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0099] a. Preparation of composite functionalized macromolecular long-chain monomer: same as Example 4.

[0100] 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.

[0101] Preparation of composite functional macromolecular long-chain branching agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace the system 5 times, and 1400g cyclohexane, 500g isoprene, and 0.85g THF were added to the polymerization kettle in sequence. After the temperature was raised to 50°C, 72mmol n-butyl lithium was added to start the reaction. Within 68min, the temperature was gradually raised from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then 190g SB / (S→B) copolymer and 45g composite functional macromolecular long-chain monomer were mixed with 1900g cyclohexane and stirred to dissolve for 58min, until they were completely dissolved, and then added to the polymerization kettle together with 2.3g THF to react for 98min; finally, 22.0g The 1,3-butadiene was capped and the reaction was carried out for 28 minutes until no free monomer was present. The colloid was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent (Mn was 7800, Mw / Mn was 10.59).

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

[0103] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0104] 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 8.5%, 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 13.0g of composite functional macromolecular long-branched 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 0.26g BPO and 180g chlorobenzene was added. After reacting for 9.6 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 2.9%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0105] Example 6

[0106] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0107] a Preparation of composite functional macromolecular long-chain monomers: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it 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 composite functional macromolecular long-chain monomer.

[0108] 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.

[0109] Preparation of composite functional macromolecular long-chain branching agent: In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 5 times, and 1500g cyclohexane, 500g isoprene, and 1.0g THF were added to the polymerizer in sequence. After the temperature was raised to 50°C, 70mmol n-butyl lithium was added to start the reaction. Within 70min, the temperature was gradually raised from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then 200g SB / (S→B) copolymer and 50g composite functional macromolecular long-chain monomer were mixed with 2000g cyclohexane and stirred for 60min to dissolve, and then added to the polymerizer together with 2.5g THF to react for 100min; finally, 25.0g The 1,3-butadiene was capped and the reaction was carried out for 30 minutes until no free monomer was present. The colloid was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent (Mn was 8000, Mw / Mn was 10.86).

[0110] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0111] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0112] 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 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 16.0g of composite functional macromolecular long-branched 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 0.30g BPO and 200g chlorobenzene was added. After reacting for 10.0 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 3.1%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0113] Comparative Example 1

[0114] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0115] a. Preparation of composite functionalized macromolecular long-chain monomers: same as in Example 1.

[0116] 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, 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 to react for 70 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.

[0117] c Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 1, except that SB / (S→B) copolymer is not added in the preparation process of the composite functional macromolecular long-chain branching grafting agent, but SB / (S→B) copolymer a is added in an amount of 150 g, that is: in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace 3 times, 1000 g cyclohexane, 500 g isoprene, and 0.25 g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 50° C., 93 mmol n-butyl lithium is added to start the reaction, and within 60 min, the temperature is gradually raised from 50° C. to 80° C. to form an IR segment with a wide vinyl distribution; then 150 g SB / (S→B) copolymer a and 25 g of composite functional macromolecular long-chain monomer are mixed with 1500 g cyclohexane and stirred for 50 min until completely dissolved, and then mixed with 1.0 g THF, added together into the polymerization kettle and reacted for 90 minutes; finally, 10.0 g of 1,3-butadiene was added into the polymerization kettle for end-capping, and the reaction was continued for 20 minutes until no free monomer was present. The gel was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent a (Mn was 5900, Mw / Mn was 6.76).

[0118] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0119] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0120] 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 composite functionalized macromolecular long-branched grafting agent is added, but a composite functionalized macromolecular long-branched grafting agent a is added, and the addition amount is 4.0 g, that is, first, 200 g of HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 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 composite functionalized macromolecular long-branched grafting agent a is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 80°C, a mixed solution of 0.10 g of BPO and 100 g of chlorobenzene is added, and after reacting for 8.0 hours, it is 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 1.9%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0121] Comparative Example 2

[0122] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0123] a. Preparation of composite functionalized macromolecular long-chain monomers: Same as Example 2.

[0124] b Preparation of SB / (S→B) copolymer: Other conditions were the same as those in Example 2, except that 150 g of 1,3-butadiene was added during the preparation of the SB / (S→B) copolymer. That is, in a 10 L stainless steel polymerizer with a jacket, the system was replaced three times by passing argon gas, 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, and then 150 g of 1,3-butadiene and 160 g of styrene were stirred and mixed for 22 min. The mixture was then added to the polymerizer in a continuous injection manner at an initial feeding rate of 70 g of the mixture / min and the feeding rate was reduced by 3 g of the mixture per minute 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 b.

[0125] c Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 2, except that SB / (S→B) copolymer is not added in the preparation process of the composite functional macromolecular long-chain branching grafting agent, but SB / (S→B) copolymer b is added in an amount of 160 g, that is: in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace 3 times, 1100 g cyclohexane, 500 g isoprene, and 0.45 g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 50° C., 85 mmol n-butyl lithium is added to start the reaction, and within 62 min, the temperature is gradually raised from 50° C. to 80° C. to form an IR segment with a wide vinyl distribution; then 160 g SB / (S→B) copolymer b and 30 g of composite functional macromolecular long-chain monomer are mixed with 1600 g cyclohexane and stirred for 52 min until completely dissolved and then mixed with 1.5 g THF, added together into the polymerization kettle and reacted for 92 minutes; finally, 13.0 g of 1,3-butadiene was added into the polymerization kettle for end-capping, and the reaction was continued for 22 minutes until no free monomer was present. The gel was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent b (Mn was 5700, Mw / Mn was 8.79).

[0126] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0127] a Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 2.

[0128] 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 composite functionalized macromolecular long-branched grafting agent is added, but a composite functionalized macromolecular long-branched grafting agent b is added, and the addition amount is 6.0 g, that is: first, 200 g of HNBR rubber is dissolved in a 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 6.0 g of composite functionalized macromolecular long-branched grafting agent b is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 82°C, a mixed solution of 0.15 g of BPO and 120 g of chlorobenzene is added, and after reacting for 8.5 hours, it is 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 2.0%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0129] Comparative Example 3

[0130] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0131] a. Preparation of composite functionalized macromolecular long-chain monomer: same as Example 3.

[0132] b Preparation of SB / (S→B) copolymer: same as Example 3.

[0133] c Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 3, except that the amount of SB / (S→B) copolymer added during the preparation of the composite functional macromolecular long-chain branching grafting agent is 100 g, that is: in a 10L stainless steel polymerizer with a jacket, the system is replaced 4 times by passing argon gas, 1200 g cyclohexane, 500 g isoprene, and 0.55 g THF are added to the polymerizer in sequence, and after the temperature is raised to 50° C., 80 mmol n-butyl lithium is added to start the reaction, and within 64 min, the temperature is gradually raised from 50° C. to 80° C. to form an IR segment with a wide vinyl distribution; then 100 g SB / (S→B) copolymer and 35 g composite functional macromolecular long-chain monomer are mixed with 1700 g cyclohexane and stirred to dissolve for 54 min, until they are completely dissolved, and then added together with 1.7 g THF to the polymerizer for reaction for 94 min; finally, 18.0 g The 1,3-butadiene was capped and the reaction was continued for 24 min until no free monomer was present. The colloid was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent c (Mn was 5600, Mw / Mn was 8.92).

[0134] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0135] a Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 3.

[0136] 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 composite functionalized macromolecular long-branched grafting agent is added, but a composite functionalized macromolecular long-branched grafting agent c is added, and the addition amount is 9.0 g, that is: first, 200 g of HNBR rubber is dissolved in a 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 9.0 g of composite functionalized macromolecular long-branched grafting agent c is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 84°C, a mixed solution of 0.20 g of BPO and 140 g of chlorobenzene is added, and after reacting for 9.0 hours, it is 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 2.2%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0137] Comparative Example 4

[0138] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0139] a. Preparation of composite functionalized macromolecular long-chain monomer: same as Example 4.

[0140] b Preparation of SB / (S→B) copolymer: same as Example 4.

[0141] c Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 4, except that the synthesis of IR segments in the preparation process of the composite functional macromolecular long-chain branching grafting agent does not adopt variable temperature polymerization, that is: in a 10L stainless steel polymerization kettle with a jacket, argon gas is passed through the system to replace 4 times, 1300g cyclohexane, 500g isoprene, and 0.75g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 50°C, 76mmol n-butyl lithium is added to start the reaction, and the reaction is carried out for 66min to form IR segments; then 180g SB / (S→B) copolymer and 40g composite functional macromolecular long-chain monomer are mixed with 1800g cyclohexane and stirred to dissolve for 56min, until they are completely dissolved, they are added together with 2.0g THF to the polymerization kettle and reacted for 96min; finally, 20.0g The 1,3-butadiene was capped and the reaction was continued for 26 min until no free monomer was present. The colloid was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent d (Mn was 7300, Mw / Mn was 7.58).

[0142] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0143] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0144] 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 composite functionalized macromolecular long-branched grafting agent is added, but a composite functionalized macromolecular long-branched grafting agent d is added, and the addition amount is 11.0 g, that is, firstly, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 8.1%, 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 11.0 g of composite functionalized macromolecular long-branched grafting agent d is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 86°C, a mixed solution of 0.23 g of BPO and 160 g of chlorobenzene is added, and after reacting for 9.2 hours, it is 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 2.4%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0145] Comparative Example 5

[0146] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0147] a. Preparation of composite functionalized macromolecular long-chain monomer: same as Example 5.

[0148] b Preparation of SB / (S→B) copolymer: same as Example 5.

[0149] c Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions were the same as those in Example 5, except that 300 g of isoprene was added during the preparation of the composite functional macromolecular long-chain branching grafting agent, namely: in a 10 L stainless steel polymerizer with a jacket, the system was replaced 5 times by passing argon, 1400 g of cyclohexane, 300 g of isoprene, and 0.85 g of THF were added to the polymerizer in sequence, and after the temperature was raised to 50° C., 72 mmol of n-butyl lithium was added to start the reaction, and within 68 min, the temperature was gradually raised from 50° C. to 80° C. to form an IR segment with a wide vinyl distribution; then 190 g of SB / (S→B) copolymer and 45 g of composite functional macromolecular long-chain monomer were mixed with 1900 g of cyclohexane and stirred for 58 min until completely dissolved and then mixed with 2.3 g of THF, added together into the polymerization kettle and reacted for 98 minutes; finally, 22.0g 1,3-butadiene was added into the polymerization kettle for end-capping, and the reaction was continued for 28 minutes until no free monomer was present. The gel was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent e (Mn was 5300, Mw / Mn was 9.13).

[0150] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0151] a Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 5.

[0152] 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 composite functionalized macromolecular long-branched grafting agent is added, but a composite functionalized macromolecular long-branched grafting agent e is added, and the amount added is 13.0 g, that is, first, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 8.5%, 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 13.0 g of composite functionalized macromolecular long-branched grafting agent e is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 88°C, a mixed solution of 0.26 g of BPO and 180 g of chlorobenzene is added, and after reacting for 9.6 hours, it is 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 2.5%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0153] Comparative Example 6

[0154] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0155] a. Preparation of composite functionalized macromolecular long-chain monomer: same as Example 6.

[0156] b Preparation of SB / (S→B) copolymer: The difference from Example 6 is that the preparation of SB / (S→B) copolymer is omitted.

[0157] c Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 6, except that SB / (S→B) copolymer is not added during the preparation of the composite functional macromolecular long-chain branching grafting agent, but small molecular monomer 1,3-butadiene is added in an amount of 200 g, that is, the amount of isoprene added is 300 g, that is, in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace 5 times, 1500 g cyclohexane, 500 g isoprene, and 1.0 g THF are added to the polymerization kettle in sequence, and after the temperature is raised to 50°C, 70 mmol n-butyl lithium is added to start the reaction, and within 70 min, the temperature is gradually raised from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then 200 g 1,3-butadiene and 50 g of the composite functional macromolecular long-chain monomer are mixed with 2000 g cyclohexane and stirred for 60 min until completely dissolved and then mixed with 2.5 g THF, added together into the polymerization kettle and reacted for 100 minutes; finally, 25.0 g of 1,3-butadiene was added into the polymerization kettle for end-capping, and the reaction was continued for 30 minutes until no free monomer was present. The gel was coagulated and dried by wet method to obtain a composite functional macromolecular long-branched grafting agent f (Mn was 7600, Mw / Mn was 8.26).

[0158] (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields:

[0159] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 6.

[0160] 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, no composite functionalized macromolecular long-branched grafting agent is added, but a composite functionalized macromolecular long-branched grafting agent f is added, and the addition amount is 16.0 g, that is: first, 200 g of HNBR rubber is dissolved in a 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 16.0 g of composite functionalized macromolecular long-branched grafting agent f is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 90°C, a mixed solution of 0.30 g of BPO and 200 g of chlorobenzene is added, and after reacting for 10.0 hours, it is 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 2.9%). Sampling analysis: Standard samples were made and the tested performance is shown in Table 1

[0161] Table 1 Performance of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields

[0162]

[0163] 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 ≤ 16% and a working temperature of -71°C.

[0164] 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 composite functionalized macromolecular long-branched grafting agent: a Preparation of composite functional macromolecular long-chain monomers: In a polymerization kettle, argon gas is introduced to replace the system, and a solvent, dihydromyrcenol, N-(4-hydroxybutyl)acrylamide, and a structure regulator are sequentially added to the polymerization kettle, 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 carried out until no free monomers are present, and the glue solution is wet-coagulated and dried to obtain a composite functional macromolecular 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 composite functional macromolecular long-chain branching grafting agent: In a polymerization kettle, argon gas is introduced to replace the system, and a solvent, isoprene, and a first structural regulator are added to the polymerization kettle in sequence, the temperature is raised, and initiator 1 is added. The reaction is a variable temperature polymerization. Within 60 to 70 minutes, the temperature gradually rises from 50°C to 80°C to form an IR segment with a wide vinyl distribution; then the SB / (S→B) copolymer and the composite functional macromolecular long-chain monomer are mixed with the solution and stirred to dissolve until they are completely dissolved and then added to the polymerization kettle together with the second structural regulator for reaction; finally, 1,3-butadiene is added to the polymerization kettle for end-capping, and the reaction is carried out until no free monomer exists. The glue solution is wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching grafting agent; (2) Preparation of compression-resistant and cold-resistant hydrogenated nitrile rubber for oil fields: a Preparation of hydrogenated nitrile rubber (HNBR): dissolving nitrile rubber in chlorobenzene solution to prepare a rubber solution, then adding the rubber solution into a reactor and introducing an inert gas to remove the air in the reactor, then removing the inert gas in the reactor with hydrogen, adding a xylene solution of Grubbs I catalyst under nitrogen protection, pressurizing, heating, reacting, cooling the system, condensing, and drying 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 composite functional macromolecular long-branched 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 composite functionalized macromolecular long-branched grafting agent has the following structure: Among them, IR is an isoprene 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 butadiene; B is a terminal 1,3-butadiene, n is the number of repeating units, and n is a positive integer of ≥1; the number average molecular weight (Mn) of the composite functionalized macromolecular long-branched grafting agent is 6000-8000, and the molecular weight distribution (Mw / Mn) is 9.13-10.

86.

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 0.05-0.15 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 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.

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

7. 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.

8. 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.

9. The preparation method according to claim 1, characterized in that: In step (1) c, the mass ratio of the solvent, isoprene, the first structural regulator, the SB / (S→B) copolymer and the composite functionalized macromolecular long-chain monomer, the solution, the second structural regulator, and 1,3-butadiene is 200%-300:100:0.05-0.2:30-40:5-10:300-400:0.2-0.5:2-5.

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 HD 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 the HNBR rubber, the composite functionalized macromolecular long-chain branching grafting agent, and chlorobenzene is 100:2-8:50-100.

13. 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 2.2% to 3.1%.

14. 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 13.

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