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

Abstract

The invention discloses a preparation method of cold-resistant and compression-resistant hydrogenated butadiene-acrylonitrile rubber for an oil field. The preparation method comprises the following steps: (1) preparing a composite functional macromolecular long branch chain grafting agent; and (2) preparing the cold-resistant and compression-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; 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 7.23-8.17. The preparation method of the cold-resistant and compression-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 cold-resistant and compression-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. CN 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, which has a compression permanent deformation resistance of ≤21% and a glass transition temperature Tg<-70°C and can meet the use requirements within the range of -70°C to -73°C. The invention firstly uses dihydromyrcenol and N-(4-hydroxybutyl) acrylamide to prepare a composite functionalized macromolecular long-chain monomer through anionic polymerization; secondly, using an anionic polymerization method, the reaction monomers are isoprene and composite functionalized macromolecular long-chain monomers, and a composite functionalized macromolecular long-chain branching grafting agent with free radical reaction activity containing a wide vinyl distribution is prepared through variable temperature polymerization; finally, the composite functionalized macromolecular long-chain branching grafting agent is grafted onto the main chain of hydrogenated nitrile rubber to prepare a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields. This method not only solves the problem of easy crystallization of hydrogenated nitrile rubber, but also improves the viscoelasticity of hydrogenated nitrile rubber, making hydrogenated nitrile rubber show very excellent low temperature resistance and deformation resistance, and achieves a balance between the low temperature resistance and deformation resistance of hydrogenated nitrile rubber. It is very suitable for oil well operations under low temperature conditions of -70℃.

[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 cold-resistant and compression-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 composite functional macromolecular long-chain branching grafting agent: In a polymerization kettle, argon 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 70°C to form an IR segment with a wide vinyl distribution; then the composite functional macromolecular long-chain monomer and the solution are mixed 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;

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

[0014] a Preparation of hydrogenated nitrile rubber (HNBR): First, the nitrile rubber is dissolved in a chlorobenzene solution to prepare a rubber solution, and then the rubber solution is added to a reactor and an inert gas is introduced to remove the air in the reactor. Then, the inert gas in the reactor is removed with hydrogen, and then a xylene solution of Grubbs I catalyst is added under nitrogen protection, pressurized, heated, reacted, the system is cooled, condensed, and vacuum dried to obtain HNBR rubber;

[0015] b. Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: HNBR rubber is dissolved in a 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 a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields;

[0016] The composite functionalized macromolecular long-branched grafting agent has the following structure:

[0017]

[0018] Among them, IR is an isoprene homopolymer segment with a wide vinyl distribution; 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 7.23-8.17.

[0019] 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.

[0020] 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 0.01-0.2 parts, preferably 0.08-0.15 parts, based on 100 parts by mass of HNBR rubber.

[0021] 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%.

[0022] 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 1,3-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).

[0023] 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.

[0024] 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.

[0025] In step (1) a of the present invention, the temperature is raised to 50-60°C.

[0026] In step (1) a of the present invention, the reaction time after adding the initiator 1 is 70 to 80 minutes; the reaction time after adding 1,3-butadiene is 30 to 40 minutes.

[0027] In step (1) b of the present invention, the mass ratio of the solvent, isoprene, the first structural regulator, the composite functionalized macromolecular long-chain monomer, the solution, the second structural regulator, and 1,3-butadiene is 300-400:100:0.1-0.5:5-10:100-200:0.1-0.3:2-5.

[0028] In step (1) b of the present invention, the stirring and dissolving time is 30 to 40 minutes; the time for adding them together into the polymerization kettle for reaction is 70 to 80 minutes; and the time for adding 1,3-butadiene for end-capping reaction is 20 to 30 minutes.

[0029] 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.

[0030] In step (2) a of the present invention, the mass fraction of nitrile rubber in the rubber solution is 3% to 6%.

[0031] 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%.

[0032] 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.

[0033] In step (2) a of the present invention, the degree of hydrogenation HD of the HNBR rubber is less than 90%.

[0034] 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 100:3-5:50-100.

[0035] In step (2) b of the present invention, the mass fraction of HNBR rubber in the rubber solution is 6% to 9%.

[0036] In step (2) of the present invention, the heating temperature is 70 to 80° C. and the reaction time is 8.0 to 10.0 hr.

[0037] In step (2) b of the present invention, the grafting rate of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 2.6% to 3.4%.

[0038] 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.

[0039] The reactor described in the present invention can be a loop reactor or a tank reactor, preferably a tank reactor.

[0040] 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.

[0041] The present invention also provides a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields obtained by the preparation method.

[0042] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0043] (1) 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 group, amide group and hydroxyl group containing long carbon chain on a macromolecular chain, fully utilizes the "aggregation effect" of macromolecules, and the "group effect" of hydroxyl group and amide group, can effectively destroy the crystallinity of HNBR, greatly reduce the glass transition temperature (Tg) of HNBR, and can prepare cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields with a glass transition temperature Tg of raw rubber <-70°C, which is suitable for oil well operations under low temperature conditions of -70°C.

[0044] (2) The composite functional macromolecular long-chain branching grafting agent prepared by the present invention is mainly prepared by using an anionic polymerization method to polymerize the reaction monomer isoprene and the composite functional macromolecular long-chain monomer through variable temperature polymerization. This grafting agent can significantly improve the viscoelasticity of HNBR and reduce the compression permanent deformation resistance of HNBR by using the "structural effect" of the branched structure of the widely distributed unsaturated "carbon-carbon" double bonds and the long-chain branches, and can prepare cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields with a compression permanent deformation of ≤21%.

[0045] (3) The composite functional macromolecular long-branched grafting agent prepared by the present invention can significantly reduce the glass transition temperature (Tg) of HNBR and improve the compression set resistance of HNBR at a low addition amount, and achieve a good "synergistic effect" in achieving a balance between cold resistance and compression set resistance.

[0046] (4) The preparation method of the cold-resistant and compression-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, and has readily available raw materials on the market, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is the infrared spectrum of the composite functionalized macromolecular long-branched grafting agent in Example 1. DETAILED DESCRIPTION

[0048] 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.

[0049] (1) Source of raw materials:

[0050]

[0051] (2) Analytical testing methods:

[0052] 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:

[0053]

[0054] 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).

[0055] 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 .

[0056] 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:

[0057] Degree of hydrogenation HD (%) = 1-unsaturation (U)

[0058] Infrared spectrum analysis of samples: The functional group analysis of nano-silica before and after modification was performed using an infrared spectrometer from German Bruke Spectrometer. The samples were dried in a vacuum oven at 100°C and pressed into a tablet using potassium bromide. The wave number range was 400-4000cm -1 .

[0059] 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.

[0060] Compression set: Execute the method in standard GB / T 7759.1-2015.

[0061] Example 1

[0062] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0063] 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.

[0064] b Preparation of composite functional macromolecular long-chain branching grafting agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace it three times, 1500g cyclohexane, 500g isoprene, and 0.5g THF were added to the polymerization kettle in sequence, the temperature was raised to 50°C, and 93mmol n-butyl lithium was added to start the reaction. Within 60min, the temperature gradually increased from 50°C to 70°C to form an IR segment with a wide vinyl distribution; then 25g of composite functional macromolecular long-chain monomer and 500g cyclohexane were mixed and stirred to dissolve for 30min, until completely dissolved, and then added to the polymerization kettle together with 0.5g THF to react for 70min; finally, 10g 1,3-butadiene was added to the polymerization kettle for end-capping, and the reaction was continued for 20min until no free monomer was present. The glue solution was wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching grafting agent (Mn was 6000, Mw / Mn was 7.23).

[0065] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0066] 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%).

[0067] b Preparation of cold-resistant and compression-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 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 70°C, a mixed solution of 0.16g 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 cold-resistant and compression-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.

[0068] Example 2

[0069] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0070] 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.

[0071] b Preparation of composite functional macromolecular long-chain branching grafting agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed through the system to replace it three times, 1600g cyclohexane, 500g isoprene, and 1.0g THF were added to the polymerization kettle in sequence, the temperature was raised to 50°C, and 87mmol n-butyl lithium was added to start the reaction. Within 62min, the temperature gradually increased from 50°C to 70°C to form an IR segment with a wide vinyl distribution; then 30g of composite functional macromolecular long-chain monomer and 600g cyclohexane were mixed and stirred to dissolve for 32min, until completely dissolved, and then added to the polymerization kettle together with 0.7g THF to react for 72min; finally, 13g 1,3-butadiene was added to the polymerization kettle for end-capping, and the reaction was continued for 22min until no free monomer was present. The glue solution was wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching grafting agent (Mn was 6500, Mw / Mn was 7.39).

[0072] (2) Preparation of cold-resistant and compression-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 32 minutes, and then 0.03g of GrubbsⅠ catalyst xylene solution (mass concentration of 6%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 12MPa, the temperature was raised to 105℃, and after reacting for 9.5hr, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=85.7%).

[0074] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 6.6% 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 7.0g 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 72°C, a mixture of 0.19g 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.8%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0075] Example 3

[0076] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0077] 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.

[0078] b Preparation of composite functional macromolecular long-chain branching grafting agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed to replace the system 4 times, 1700g cyclohexane, 500g isoprene, and 1.5g THF were added to the polymerization kettle in sequence, the temperature was raised to 50°C, and 82mmol n-butyl lithium was added to start the reaction. Within 64min, the temperature gradually increased from 50°C to 70°C to form an IR segment with a wide vinyl distribution; then 35g of composite functional macromolecular long-chain monomer and 700g cyclohexane were mixed and stirred to dissolve for 34min, until completely dissolved, and then added to the polymerization kettle together with 0.9g THF to react for 74min; finally, 15g 1,3-butadiene was added to the polymerization kettle for end-capping, and the reaction was continued for 24min until no free monomer was present. The glue solution was wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching grafting agent (Mn was 7000, Mw / Mn was 7.68).

[0079] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0080] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 4% 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 34 minutes, and then 0.05g of GrubbsⅠ catalyst xylene solution (mass concentration was 7%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 12MPa, and the temperature was raised to 110°C. After reacting for 10 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=86.2%).

[0081] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 7.4% 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 8.0g 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 74°C, a mixture of 0.22g 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.0%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0082] Example 4

[0083] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0084] 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.

[0085] b Preparation of composite functional macromolecular long-chain branching grafting agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed to replace the system 4 times, 1800g cyclohexane, 500g isoprene, and 2.0g THF were added to the polymerization kettle in sequence, the temperature was raised to 50°C, and 79mmol n-butyl lithium was added to start the reaction. Within 66min, the temperature gradually increased from 50°C to 70°C to form an IR segment with a wide vinyl distribution; then 40g of composite functional macromolecular long-chain monomer and 800g cyclohexane were mixed and stirred to dissolve for 36min, until completely dissolved, and then added to the polymerization kettle together with 1.0g THF to react for 76min; finally, 19g 1,3-butadiene was added to the polymerization kettle for end-capping, and the reaction was continued for 26min until no free monomer was present. The glue solution was wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching grafting agent (Mn was 7400, Mw / Mn was 7.86).

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

[0087] 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%).

[0088] b Preparation of cold-resistant and compression-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 8.0%, 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 76°C, a mixture of 0.24g BPO and 160g chlorobenzene was added. After reacting for 9.3 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-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.

[0089] Example 5

[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 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, 137mmol 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 carried out for 38min 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 composite functional macromolecular long-chain branching grafting agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed to replace the system 5 times, 1900g cyclohexane, 500g isoprene, and 2.2g THF were added to the polymerization kettle in sequence, the temperature was raised to 50°C, and 74mmol n-butyl lithium was added to start the reaction. Within 68min, the temperature gradually increased from 50°C to 70°C to form an IR segment with a wide vinyl distribution; then 45g of composite functional macromolecular long-chain monomer and 900g cyclohexane were mixed and stirred to dissolve for 38min, until completely dissolved, and then added to the polymerization kettle together with 1.3g THF to react for 78min; finally, 22g 1,3-butadiene was added to the polymerization kettle for end-capping, and the reaction was continued for 28min until no free monomer was present. The glue solution was wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching grafting agent (Mn was 7800, Mw / Mn was 7.98).

[0093] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0094] 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%).

[0095] b Preparation of cold-resistant and compression-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 8.4%, 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 9.5g 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 78°C, a mixture of 0.27g BPO and 180g chlorobenzene was added. After reacting for 9.7 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.3%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0096] Example 6

[0097] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0098] 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.

[0099] b Preparation of composite functional macromolecular long-chain branching grafting agent: In a 10L stainless steel polymerization kettle with a jacket, argon was passed to replace the system 5 times, 200g cyclohexane, 500g isoprene, and 2.5g THF were added to the polymerization kettle in sequence, the temperature was raised to 50°C, and 71mmol n-butyl lithium was added to start the reaction. Within 70min, the temperature gradually increased from 50°C to 70°C to form an IR segment with a wide vinyl distribution; then 50g of composite functional macromolecular long-chain monomer and 1000g cyclohexane were mixed and stirred to dissolve for 40min, until completely dissolved and added to the polymerization kettle together with 1.5g THF to react for 80min; finally, 25g 1,3-butadiene was added to the polymerization kettle for end-capping, and the reaction was continued for 30min until no free monomer was present. The glue solution was wet-coagulated and dried to obtain a composite functional macromolecular long-chain branching grafting agent (Mn was 8000, Mw / Mn was 8.17).

[0100] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0101] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 6.0% 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 by hydrogen for 40 minutes, and then 0.1g of GrubbsⅠ catalyst xylene solution (mass concentration of 10%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 14MPa, and the temperature was raised to 120°C. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=89.4%).

[0102] b Preparation of cold-resistant and compression-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 10.0g 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 0.30g 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.4%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0103] Comparative Example 1

[0104] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0105] Preparation of a composite functional macromolecular long-chain monomer: Other conditions are the same as those in Example 1, except that N-(4-hydroxybutyl) acrylamide is not added during the preparation of the composite functional macromolecular long-chain monomer, but acrylamide is added in an amount of 200 g, that is: in a 10L stainless steel polymerizer with a jacket, the system is replaced 3 times by passing argon gas, 1000 g cyclohexane, 300 g dihydromyrcenol, 200 g acrylamide, and 0.5 g THF are added to the polymerizer in sequence, the temperature is raised to 50° C., and 150 mmol n-butyl lithium is added to the polymerizer for reaction for 70 min; finally, 10 g 1,3-butadiene is added to the polymerizer for end-capping, and the reaction is carried out for 30 min until no free monomer is present, and the glue is wet-coagulated and dried to obtain a composite functional macromolecular long-chain monomer a.

[0106] b Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 1, except that composite functional macromolecular long-chain monomer is not added in the preparation process of composite functional macromolecular long-chain branching grafting agent, but composite functional macromolecular long-chain monomer a is added in an amount of 25 g, that is: in a 10L stainless steel polymerization kettle with a jacket, argon is passed through the system to replace 3 times, 1500g cyclohexane, 500g isoprene, 0.5g THF are added to the polymerization kettle in sequence, the temperature is raised to 50°C, 93mmol n-butyl lithium is added to start the reaction, and within 60min, the temperature is gradually raised from 50°C to 70°C to form an IR segment with a wide vinyl distribution; then 25g of composite functional macromolecular long-chain monomer a and 500g of cyclohexane are mixed and stirred to dissolve for 30min, until completely dissolved, and then added to the polymerization kettle together with 0.5g THF to react for 70min; finally, 10g of The 1,3-butadiene was capped and the reaction was continued for 20 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 a (Mn was 5900, Mw / Mn was 6.91).

[0107] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0108] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0109] b Preparation of cold-resistant and compression-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 cold-resistant and compression-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 6.0 g, that is: first, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a 6% glue solution by mass, 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 a is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 70°C, a mixed solution of 0.16 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.3%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0110] Comparative Example 2

[0111] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0112] Preparation of a composite functional macromolecular long-chain monomer: The other conditions are the same as those in Example 2, except that dihydromyrcenol is not added during the preparation of the composite functional macromolecular long-chain monomer, but allyl alcohol is added in an amount of 310 g, that is: in a 10L stainless steel polymerizer with a jacket, the system is replaced 3 times by passing argon gas, 1100 g cyclohexane, 310 g allyl alcohol, 190 g N-(4-hydroxybutyl) acrylamide, and 0.7 g THF are added to the polymerizer in sequence, the temperature is raised to 52° C., and 147 mmol n-butyl lithium is added to the polymerizer for reaction for 72 min; finally, 13 g 1,3-butadiene is added to the polymerizer for end-capping, and the reaction is carried out for 32 min until no free monomer is present, and the glue is wet-coagulated and dried to obtain a composite functional macromolecular long-chain monomer b.

[0113] b Preparation of composite functionalized macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 2, except that composite functionalized macromolecular long-chain monomer b is added in an amount of 30 g instead of composite functionalized macromolecular long-chain monomer b in a preparation process of composite functionalized macromolecular long-chain branching grafting agent, namely: in a 10L stainless steel polymerization kettle with a jacket, the system is replaced 3 times by passing argon gas, 1600 g cyclohexane, 500 g isoprene, and 1.0 g THF are added to the polymerization kettle in sequence, the temperature is raised to 50° C., 87 mmol n-butyl lithium is added to start the reaction, and the temperature is gradually raised from 50° C. to 70° C. within 62 min to form an IR segment with a wide vinyl distribution; then 30 g of composite functionalized macromolecular long-chain monomer b and 600 g of cyclohexane are mixed and stirred to dissolve for 32 min, until completely dissolved and added to the polymerization kettle together with 0.7 g THF to react for 72 min; finally, 13 g of The 1,3-butadiene was capped and the reaction was continued for 22 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 b (Mn was 5700, Mw / Mn was 5.75).

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

[0115] a. Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 2.

[0116] b Preparation of cold-resistant and compression-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 cold-resistant and compression-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 7.0 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 6.6%, 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 7.0 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 72°C, a mixed solution of 0.19 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.6%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0117] Comparative Example 3

[0118] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0119] Preparation of a composite functional macromolecular long-chain monomer: The other conditions are the same as those in Example 3, except that N-(4-hydroxybutyl) acrylamide is not added during the preparation of the composite functional macromolecular long-chain monomer, that is, in a 10L stainless steel polymerizer with a jacket, the system is replaced 4 times by argon, 1200g of cyclohexane, 320g of dihydromyrcenol, and 0.9g of THF are added to the polymerizer in sequence, the temperature is raised to 54°C, and 143mmol of n-butyl lithium is added to the polymerizer for reaction for 74min; finally, 17g of 1,3-butadiene is added to the polymerizer for end-capping, and the reaction is carried out for 34min until no free monomer is present, and the colloid is wet-coagulated and dried to obtain a composite functional macromolecular long-chain monomer c.

[0120] b Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 3, except that composite functional macromolecular long-chain monomer c is added in an amount of 35 g instead of composite functional macromolecular long-chain monomer c in a preparation process of composite functional macromolecular long-chain branching grafting agent, namely: in a 10L stainless steel polymerization kettle with a jacket, the system is replaced 4 times by passing argon gas, 1700 g cyclohexane, 500 g isoprene, and 1.5 g THF are added to the polymerization kettle in sequence, the temperature is raised to 50° C., 82 mmol n-butyl lithium is added to start the reaction, and the temperature is gradually raised from 50° C. to 70° C. within 64 min to form an IR segment with a wide vinyl distribution; then 35 g composite functional macromolecular long-chain monomer c and 700 g cyclohexane are mixed and stirred to dissolve for 34 min, until completely dissolved and added to the polymerization kettle together with 0.9 g THF to react for 74 min; finally, 15 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 5200, Mw / Mn was 5.23).

[0121] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0122] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 3.

[0123] b Preparation of cold-resistant and compression-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 cold-resistant and compression-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 8.0 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 7.4%, 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 8.0 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 74°C, a mixed solution of 0.22 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.3%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0124] Comparative Example 4

[0125] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0126] a Preparation of composite functional macromolecular long-chain monomer: The other conditions are the same as those in Example 4, except that the amount of N-(4-hydroxybutyl)acrylamide added during the preparation of the composite functional macromolecular long-chain monomer is 100 g, that is, in a 10L stainless steel polymerizer with a jacket, the system is replaced 4 times by passing argon, 1300 g of cyclohexane, 330 g of dihydromyrcenol, 100 g of N-(4-hydroxybutyl)acrylamide, and 1.1 g of THF are added to the polymerizer in sequence, the temperature is raised to 56° C., and 140 mmol of n-butyl lithium is added to the polymerizer for reaction for 76 min; finally, 20 g of 1,3-butadiene is added to the polymerizer for end-capping, and the reaction is carried out for 36 min until no free monomer is present, and the glue is wet-coagulated and dried to obtain composite functional macromolecular long-chain monomer d.

[0127] b Preparation of composite functional macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 4, except that composite functional macromolecular long-chain monomer d is added in an amount of 40 g instead of composite functional macromolecular long-chain monomer d in the preparation process of the composite functional macromolecular long-chain branching grafting agent, that is: in a 10L stainless steel polymerization kettle with a jacket, the system is replaced 4 times by passing argon gas, 1800 g cyclohexane, 500 g isoprene, and 2.0 g THF are added to the polymerization kettle in sequence, the temperature is raised to 50° C., 79 mmol n-butyl lithium is added to start the reaction, and the temperature is gradually raised from 50° C. to 70° C. within 66 min to form an IR segment with a wide vinyl distribution; then 40 g of composite functional macromolecular long-chain monomer d and 800 g of cyclohexane are mixed and stirred to dissolve for 36 min, until completely dissolved, and then added to the polymerization kettle together with 1.0 g THF to react for 76 min; finally, 19 g of 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 5700, Mw / Mn was 7.12).

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

[0129] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0130] b Preparation of cold-resistant and compression-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 cold-resistant and compression-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 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 8.0%, 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 d is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 76°C, a mixed solution of 0.24 g of BPO and 160 g of chlorobenzene is added, and after reacting for 9.3 hours, it is flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.1%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0131] Comparative Example 5

[0132] (1) Preparation of composite functionalized macromolecular long-branched grafting agent:

[0133] The other conditions are the same as those in Example 5, except that in the preparation process of the composite functionalized macromolecular long-chain branching grafting agent, no composite functionalized macromolecular long-chain monomer is added, but a small molecular reactive monomer N-(4-hydroxybutyl) acrylamide is added in an amount of 45 g, that is: in a 10L stainless steel polymerizer with a jacket, the system is replaced 5 times by argon, 1900 g cyclohexane, 500 g isoprene, and 2.2 g THF are added to the polymerizer in sequence, the temperature is raised to 50° C., 74 mmol n-butyl lithium is added to start the reaction, and the temperature is gradually raised from 50° C. to 70° C. within 68 min to form an IR segment with a wide vinyl distribution; then 45 g N-(4-hydroxybutyl) acrylamide and 900 g cyclohexane are mixed and stirred to dissolve for 38 min, until completely dissolved and added to the polymerizer together with 1.3 g THF to react for 78 min; finally, 22 g The 1,3-butadiene was capped and the reaction was continued for 28 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 e (Mn was 4900, Mw / Mn was 4.63).

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

[0135] a Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 5.

[0136] b Preparation of cold-resistant and compression-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 cold-resistant and compression-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 addition amount is 9.5 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 8.4%, 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 9.5 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 78°C, a mixed solution of 0.27 g of BPO and 180 g of chlorobenzene is added, and after reacting for 9.7 hours, it is flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain cold-resistant and compression-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.

[0137] Comparative Example 6

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

[0139] a. Preparation of composite functionalized macromolecular long-chain monomer: same as Example 6.

[0140] b. Preparation of composite functionalized macromolecular long-branched grafting agent: same as Example 6.

[0141] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0142] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 6.

[0143] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: Other conditions are the same as those in Example 6, except that the amount of BPO added during the preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 0.005 g, that is, first 200 g HNBR rubber is dissolved in chlorobenzene solution to form a 9.0% glue solution by mass, then the glue solution is added to a 10L stainless steel reactor with a jacket, nitrogen is introduced for replacement 5 times, and then 10.0 g of a composite functional macromolecular long-branched grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of 0.005 g BPO and 200 g chlorobenzene is added when the reactor temperature reaches 80°C, reacted for 10.0 hours, flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 1.6%). Sampling analysis: Standard samples are made, and the tested performance is shown in Table 1.

[0144] Table 1 Performance of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields

[0145]

[0146] It can be seen from Table 1 that the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields of the present invention has a low glass transition temperature and a small compression permanent deformation and is suitable for oil well operations under low temperature conditions of -70°C.

[0147] Figure 1 This is the infrared spectrum of the composite functionalized macromolecular long-branched grafting agent in Example 1. Figure 1 It can be seen that the wave number is 3600~35100cm -1 The asymmetric secondary contraction vibration double absorption peak appears at 2950~2800cm -1 The secondary contraction vibration absorption peak of methyl (CH3) appears at 1680~1500cm -1 The secondary contraction vibration absorption peak of "carbon-carbon double bond" appears at 1630~1520cm -1 The secondary contraction vibration absorption peak of the amide group appears at , indicating that the composite functionalized macromolecular long-branched grafting agent prepared from dihydromyrcenol, N-(4-hydroxybutyl)acrylamide and isoprene contains structures such as amide group, hydroxyl group, methyl group and "carbon-carbon double bond".

[0148] 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 cold-resistant and compression-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 composite functional macromolecular long-chain branching grafting agent: In a polymerization kettle, argon 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 70°C to form an IR segment with a wide vinyl distribution; then the composite functional macromolecular long-chain monomer and the solution are mixed 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 cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: a Preparation of hydrogenated nitrile rubber (HNBR): First, the nitrile rubber is dissolved in a chlorobenzene solution to prepare a rubber solution, and then the rubber solution is added to a reactor and an inert gas is introduced to remove the air in the reactor. Then, the inert gas in the reactor is removed with hydrogen, and then a xylene solution of Grubbs I catalyst is added under nitrogen protection, pressurized, heated, reacted, the system is cooled, condensed, and vacuum dried to obtain HNBR rubber; b. Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: HNBR rubber is dissolved in a 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 a cold-resistant and compression-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; 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 7.23-8.

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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 0.01-0.2 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, isoprene, the first structural regulator, the composite functionalized macromolecular long-chain monomer, the solution, the second structural regulator, and 1,3-butadiene is 300-400:100:0.1-0.5:5-10:100-200:0.1-0.3:2-5.

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

1.

10. 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%.

11. 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-branched grafting agent, and chlorobenzene is 100:3-5:50-100.

12. The preparation method according to claim 1, characterized in that: In step (2) b, the grafting rate of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 2.6% to 3.4%.

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

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