A low temperature grade hydrogenated nitrile rubber with high deformation resistance and a method for preparing the same

Abstract

This invention discloses a deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber and its preparation method. The preparation method includes: (1) preparation of a macromolecular long-branched linking agent and (2) preparation of the deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber. The macromolecular long-branched linking agent has the following structure: wherein BR is a 1,3-butadiene homopolymer segment, and R is C6~C6. 12 The linear alkyl group; m and n are the number of repeating units, n is a positive integer ≥ 1, and m is a positive integer ≥ 1; the number average molecular weight (Mn) of the macromolecular long-linked branching agent is 7000-9000. The method for preparing the deformation-resistant, low-temperature hydrogenated nitrile butadiene rubber of this invention is characterized by being green and environmentally friendly, having a high and stable modification effect, a low addition ratio, readily available commercial raw materials, and suitability for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of rubber technology, specifically relating to a deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber modified with a macromolecular unsaturated long-chain branching agent and its preparation method. Background Technology

[0002] Hydrogenated nitrile butadiene rubber (HNBR) is prepared by selectively hydrogenating the carbon-carbon double bonds in nitrile butadiene rubber. Therefore, HNBR not only retains the oil resistance, corrosion resistance and elasticity of NBR, but also exhibits superior aging resistance and high temperature resistance. Furthermore, its mechanical properties such as tensile strength, elongation at break, abrasion resistance and hardness are improved. It is widely used in oil exploration equipment such as pump pistons, rotary hoses, valve seals, and drill pipe covers.

[0003] While hydrogenation of the carbon-carbon double bonds endows HNBR with excellent properties, it also introduces a serious drawback: the main chain of hydrogenated nitrile butadiene rubber (NBR) is a highly ordered polyethylene structure, which readily forms a crystalline structure, leading to an increase in temperature glycation (Tg). Consequently, HNBR products exhibit poor low-temperature resistance. Since most of my country's oil drilling operations are concentrated in the western and northeastern regions, where minimum temperatures can reach around -50°C, oil drilling equipment faces extremely demanding low-temperature resistance from rubber sealing materials.

[0004] In the prior art, there are many patent documents reporting methods for preparing low-temperature resistant hydrogenated nitrile butadiene rubber. For example:

[0005] CN 106349410 B discloses a special hydrogenated nitrile butadiene rubber with compression cold resistance and its preparation method. The rubber backbone contains epoxy groups, some of which are also attached to ester side groups. The ester side groups are generated by a ring-opening reaction between C6-C24 acid anhydrides and the epoxy groups. The preparation method includes introducing epoxy groups into the rubber molecular backbone, and then reacting some of the epoxy groups with acid anhydrides under the action of a catalyst to introduce ester groups, thereby obtaining a special hydrogenated nitrile butadiene rubber containing epoxy groups and ester groups. CN 105294939B discloses a low-temperature grade hydrogenated nitrile butadiene rubber raw rubber, which is a copolymer of butadiene, acrylonitrile, and dibutyl transbutenedioate, with a number-average molecular weight of 1.05–3.25 × 10⁻⁶. 5 The weight-average molecular weight is 3.02–9.32 × 10⁻⁶. 5The polydispersity index is 2.0–2.7; the degree of hydrogenation of the low-temperature grade hydrogenated nitrile butadiene rubber raw rubber is above 90%, and the glass transition temperature is -38℃ to -42℃. CN 112592461 B discloses a modified hydrogenated nitrile butadiene rubber material with low-temperature resistance and high damping characteristics, its preparation method, and its application. The modified hydrogenated nitrile butadiene rubber material is prepared using HNBR / PNB block copolymer as raw material; the HNBR / PNB block copolymer is obtained by modifying NBR or HNBR through olefin metathesis reaction using norbornene monomer as a modifier. CN 115594898A discloses a low-temperature resistant hydrogenated nitrile butadiene rubber compound and its internal mixing preparation method. The method mainly involves blending and internal mixing hydrogenated nitrile butadiene raw rubber, plasticizer, and hardness modifier to obtain a low-temperature resistant hydrogenated nitrile butadiene rubber compound with a Shore A hardness of 67±5, tensile strength ≥14MPa, elongation at break ≥180%, compression set ≤35%, and a 45℃ compression set ≥0.16. CN 105754164A discloses a low-temperature resistant rubber material. Although this material has improved low-temperature resistance, the addition of the plasticizer dioctyl phthalate (DOP) reduces the material's mechanical properties and oil resistance. Furthermore, DOP is not environmentally friendly and is prone to leaching. Zhang Dongheng et al. disclosed that by blending ethylene propylene rubber (EPDM) with HNBR, the low-temperature performance of HNBR was improved. When the EPDM content was 15%, the Tg decreased by 3°C. However, with further increasing the EPDM content, the Tg of the blended rubber no longer decreased (Synthetic Rubber Industry, 2002, 25(1)). ).

[0006] While the low-temperature resistance of hydrogenated nitrile butadiene rubber can be improved to some extent by adding small-molecule modifiers, copolymerization, and blending, these methods still have certain limitations. Their preparation methods are complex, difficult to implement, require large amounts of additives, are costly, and have limited modification effects. Summary of the Invention

[0007] To address the problems of existing technologies, this invention provides a method for preparing a deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR) with a compression set ≤28% and a glass transition temperature (Tg) <-55℃, meeting the requirements for use in the -55℃ to -57℃ temperature range. This invention first synthesizes a homopolymer containing unsaturated double bonds using anionic polymerization. Then, it reacts with a long-chain α-olefin monomer and ethylene under the action of a nickel-based complexing catalyst to prepare a macromolecular long-chain grafting agent with free radical reactivity. Finally, the macromolecular long-chain grafting agent is grafted onto the main chain of the HNBR to prepare a deformation-resistant, low-temperature-grade HNBR for oilfield use. This method solves the problem of easy crystallization in HNBR, enabling it to exhibit not only excellent low-temperature performance but also sufficient deformation resistance, achieving a balance between low-temperature performance and deformation resistance. It is highly suitable for oil well operations under conditions of -55℃ and a compression set ≤28%.

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

[0009] To achieve the above objectives, the present invention provides a method for preparing deformation-resistant, low-temperature-grade hydrogenated nitrile rubber, the preparation process comprising the following steps:

[0010] (1) Preparation of macromolecular long-branched linking agents:

[0011] Preparation of 1,3-butadiene homopolymer (BR): Argon gas was introduced into the polymerization reactor for purging. Solvent, 1,3-butadiene, structure modifier and initiator 1 were added to the polymerization reactor in sequence. The temperature was raised and the reaction was carried out until no free monomers were present. The glue solution was wet coagulated and dried to obtain BR homopolymer.

[0012] b. Preparation of macromolecular long-branched linking agent: Inert gas was introduced into the reactor for purging, solvent was added, the temperature was raised, and alkylaluminoxane co-catalyst was added under stirring. Stirring was continued under inert gas protection. Then, BR homopolymer and solution were mixed and stirred to dissolve until completely dissolved. Then, it was added to a high-pressure reactor together with long-chain α-olefin and nickel-based complexing catalyst. Ethylene was introduced at this time, and the reaction was carried out. After the reaction was completed, the macromolecular long-branched linking agent was obtained by centrifugation and drying.

[0013] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

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

[0015] b. Preparation of deformation-resistant, low-temperature hydrogenated nitrile butadiene rubber: HNBR rubber is dissolved in chlorobenzene solution to prepare a rubber solution. The rubber solution is then added to a reaction vessel, and an inert gas is introduced for purging. Then, a macromolecular long-branched linking agent is added to the reaction vessel, stirred and mixed, heated, and a mixture of initiator 2 and chlorobenzene is added. The reaction is carried out, flocculated with anhydrous ethanol, washed, and dried to obtain deformation-resistant, low-temperature hydrogenated nitrile butadiene rubber.

[0016] The macromolecular long-branched linker has the following structure:

[0017]

[0018] Wherein, BR is the 1,3-butadiene homopolymer segment, and R is C6~C6. 12 The linear alkyl group; m and n are the number of repeating units, n is a positive integer ≥ 1, and m is a positive integer ≥ 1; the number average molecular weight (Mn) of the macromolecular long-linked branching agent is 7000 to 9000.

[0019] The long-chain α-olefin described in this invention is a C6-C6 α-olefin. 12 The straight-chain olefin may be selected from one of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene, with 1-octene being preferred.

[0020] The nickel-based complexing catalyst of the present invention is selected from one of (1-naphthyl)[8-(diphenylphosphino)quinoline]nickel, trans-phenylbromo(di(triphenylphosphine))nickel and 2,5-dicarboxypyrrole dibromide, preferably trans-phenylbromo(di(triphenylphosphine))nickel.

[0021] The alkylaluminoxane cocatalyst described in this invention is selected from one of methylaluminoxane (MAO) and ethylaluminoxane (EAO), with methylaluminoxane being preferred.

[0022] The initiator 1 described in this invention is a hydrocarbon-based monolithium compound, namely RLi, wherein R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic group, or a complex group containing 1 to 20 carbon atoms. This hydrocarbon-based monolithium compound is selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthenelithium, cyclohexyllithium, and dodecyllithium, preferably n-butyllithium. The amount of organolithium added is determined by the molecular weight of the designed polymer.

[0023] The initiator 2 described in this invention is an organic peroxide selected from one of diacetyl peroxide, diisobutyryl peroxide, cumene hydroperoxide, dicumene peroxide (DCP), and dibenzoyl peroxide, preferably dicumene peroxide (DCP). The amount added is 0.01 to 0.1 parts, preferably 0.04 to 0.06 parts, based on 100 parts by weight of HNBR rubber.

[0024] The nitrile rubber of this invention is copolymerized from 1,3-butadiene and acrylonitrile via emulsion polymerization. The acrylonitrile content of the nitrile rubber is 20 wt% to 42 wt%, preferably 22 wt% to 35 wt%.

[0025] The structure modifier described in this invention is a polar organic compound that produces a solvation effect in the polymerization system, enabling it to adjust the reactivity ratio of styrene and 1,3-butadiene, thus allowing them to copolymerize randomly. This type of polar organic compound is selected from one of diethylene glycol dimethyl ether (2G), tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, diethylene glycol dimethyl ether (DME), and triethylamine, preferably tetrahydrofuran (THF).

[0026] The solvent or solution described in this invention may be selected from one of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene, and xylene, with cyclohexane being preferred.

[0027] In step (1)a of the present invention, the mass ratio of the solvent, 1,3-butadiene and the structure modifier is 2-4:1:0.005-0.01.

[0028] In step (1)a of the present invention, the temperature is raised to 50-60°C; the reaction time is 60-70 min.

[0029] In step (1)b of the present invention, the mass ratio of the solvent, alkylaluminoxane co-catalyst, BR homopolymer, solution, long-chain α-olefin, and nickel-based complex catalyst is 400-500: 20-30: 3.0-5.0: 100-200: 10-20: 1.

[0030] In step (1)b of the present invention, the temperature is raised to 80-90°C, the stirring speed is 700-800 rpm, the stirring is continued for 20-30 min, the stirring and dissolving time is 30-50 min, the reaction pressure is 15-20 MPa, and the reaction time is 4.0-6.0 hr.

[0031] 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, based on 100 parts by mass of nitrile rubber; the degree of hydrogenation of the HNBR rubber is HD<90%.

[0032] In step (2)a of the present invention, the mass fraction of the adhesive solution is 3% to 6%.

[0033] In step (2)a of this invention, the mass concentration of the xylene solution of the Grubbs I catalyst is 5% to 10%.

[0034] In step (2)a of the present invention, the pressure is increased to 11-14 MPa; the temperature is increased to 100-120°C; and the reaction time is 9-11 hours.

[0035] In step (2)b of the present invention, the mass ratio of the HNBR rubber, the macromolecular long-branched linker, and the chlorobenzene is 100:3-5:100-200.

[0036] In step (2)b of the present invention, the mass concentration of HNBR rubber in the adhesive solution is 6% to 9%.

[0037] In step (2)b of the present invention, the heating temperature is 80-90°C and the reaction time is 8.0-9.0 hr.

[0038] In step (2)b of the present invention, the grafting rate of the deformation-resistant, low-temperature grade hydrogenated nitrile rubber is 2.9% to 3.7%.

[0039] The polymerization reactions described in this invention are carried out in an oxygen-free, anhydrous, and inert gas environment. The inert gas is nitrogen or a gas of a group 0 element in the periodic table, excluding radon, with nitrogen being preferred.

[0040] The reaction vessel described in this invention can be a loop reactor or a batch reactor, preferably a batch reactor.

[0041] In step (2)a of this invention, pressurization is achieved by adding hydrogen gas. The amount of hydrogen gas added is well known to those skilled in the art, and the amount of hydrogen gas added is within the conventional addition range in the prior art. This invention does not impose any special limitations on this.

[0042] The present invention also provides a deformation-resistant, low-temperature-grade hydrogenated nitrile rubber obtained by the above preparation method.

[0043] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0044] (1) The macromolecular long-branched grafting agent prepared in this invention is synthesized into 1,3-butadiene homopolymer by anionic polymerization, and then synthesized into a macromolecular long branched chain by coordination polymerization with long-chain α-olefin. It is activated by ethylene to make it free radical reactive and can be grafted onto hydrogenated nitrile butadiene rubber. A long-chain branched structure containing unsaturated double bonds is formed on the main chain structure of hydrogenated nitrile butadiene rubber. This structure organically combines the long branched structure and the unsaturated double bond structure into a whole, achieving a good "synergistic effect" in reducing the crystallinity and viscoelasticity of HNBR. It can greatly reduce the glass transition temperature (Tg) of HNBR with a low addition amount, while also significantly improving the compression set resistance of HNBR. It can prepare a deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber with a compression set resistance ≤28% and a glass transition temperature Tg <-55℃.

[0045] (2) The deformation-resistant, low-temperature hydrogenated nitrile rubber prepared by the present invention, under the condition of ensuring a certain degree of hydrogenation, makes full use of the "stacking effect" and "group effect" of the long branched structure and unsaturated double bond, and achieves a balance between the low temperature and deformation resistance of the hydrogenated nitrile rubber, which is suitable for oil well operations under low temperature conditions of -55℃.

[0046] (3) The method for preparing deformation-resistant, low-temperature hydrogenated nitrile rubber of the present invention has the characteristics of being green and environmentally friendly, having a high efficiency and stable modification effect, low addition ratio, readily available raw materials, and being suitable for industrial production. Detailed Implementation

[0047] The following examples and comparative examples illustrate the inventive effects of the present invention, but the scope of protection of the present invention is not limited to these examples and comparative examples. The raw materials used in the examples are all industrial grade, purified before use, and have no other special requirements. The "parts" mentioned in the examples and comparative examples refer to parts by weight.

[0048] (1) Source of raw materials:

[0049]

[0050] (2) Analysis and testing methods:

[0051] Grafting rate determination: Approximately 4g of sample was pipetted from a three-necked flask into a weighing bottle. After weighing, 2-3 drops of hydroquinone solution were added, and the sample was dried to constant weight. The sample was then placed in a Soxhlet extractor and extracted with toluene in a 90°C water bath for 24 hours, followed by drying to constant weight. The monomer grafting rate was calculated using the following formula:

[0052]

[0053] Where: m0—total mass of adhesive (g); m—mass of the sample taken after reaction (g); m m —Total mass of monomers in the reactants (g); m HNBR —The mass of hydrogenated nitrile rubber in the sample (g); m1—The mass of the sample after extraction (g).

[0054] Molecular weight determination: Molecular weight was determined using a Waters 2414 gel permeation chromatography (GPC) system (Waters, Inc., USA). A polystyrene standard was used as the calibration curve. The mobile phase was tetrahydrofuran, the column temperature was 40℃, the sample concentration was 1 mg / mL, the injection volume was 50 μL, the elution time was 40 min, and the flow rate was 1 mL / min. -1 .

[0055] Determination of HNBR hydrogenation degree: using nuclear magnetic resonance hydrogen spectroscopy (NMR spectroscopy). 1 The degree of hydrogenation of hydrogenated nitrile butadiene rubber (NMR) is calculated using the following main methods: 1. The product is completely dissolved in deuterated chloroform to prepare a 1H NMR sample; 2. The 1H NMR spectrum is measured and analyzed: The degree of hydrogenation of hydrogenated nitrile butadiene rubber is determined by 1H NMR spectroscopy and calculated using the following methods: characteristic proton peak of 1,4-C=C-: 5.4 ppm, characteristic proton peak of 1,2-C=C-: 5.0 ppm, characteristic proton peak of saturated hydrocarbons: 1.25 ppm, characteristic proton peak of cyano-linked groups: 2.5 ppm. The formula for calculating the degree of hydrogenation is as follows:

[0056] Degree of hydrogenation (HD%) = 1 - Degree of unsaturation (U)

[0057] Determination of glass transition temperature (Tg): The glass transition temperature of the product was measured using DSC. The instrument model was DSC1, manufactured by Mettler AG, Switzerland. The heating range was -80 to 80 °C, and the heating rate was 10 °C / min.

[0058] Compression set: The method specified in standard GB / T 7759.1-2015 shall be followed.

[0059] Example 1

[0060] (1) Preparation of macromolecular long-branched linking agents:

[0061] Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 1000g cyclohexane, 500g 1,3-butadiene, 2.5g THF, and 171mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 50℃ and the reaction was carried out for 60min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the BR homopolymer.

[0062] b. Preparation of macromolecular long-branched linking agent: First, nitrogen was purged three times in a 10L high-pressure reactor. 4000g of cyclohexane was added, and the temperature was raised to 80℃. Then, 200g of methylaluminoxane co-catalyst was added dropwise under uniform stirring at 700rpm. Stirring was continued for 20min under nitrogen protection. Subsequently, 30g of BR homopolymer and 1000g of cyclohexane were mixed and stirred for 30min to dissolve. Then, 100g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced, and the pressure was maintained at 15MPa for 4.0hr. After the reaction was completed, the macromolecular long-branched linking agent (number average molecular weight Mn of 7000) was obtained by centrifugation and drying.

[0063] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0064] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2707 was dissolved in chlorobenzene solution to prepare a 3% (w / w) rubber solution. Then, the rubber solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 30 minutes. Then, under nitrogen protection, 0.02g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 11MPa, and the temperature was raised to 100℃. After reacting for 9.0 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 84.1%).

[0065] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR): First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced three times for purging. Next, 6.0g of a macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 80℃, a mixture of 0.08g of DCP and 200g of chlorobenzene was added. After reacting for 8.0 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (grafting rate 2.9%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0066] Example 2

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

[0068] Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerization reactor with a jacket, the system was purged three times with argon gas. 1300g cyclohexane, 500g 1,3-butadiene, 3.0g THF, and 182mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 52℃ and the reaction was carried out for 62min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the BR homopolymer.

[0069] b. Preparation of macromolecular long-branched linking agent: First, nitrogen was purged three times in a 10L high-pressure reactor, and 4200g of cyclohexane was added. After heating to 82℃, 210g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 720rpm. Stirring was continued for 22min under nitrogen protection. Then, 35g of BR homopolymer and 1200g of cyclohexane were mixed and stirred to dissolve for 35min. Then, 120g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced and the pressure was maintained at 16MPa for 4.5hr. After the reaction was completed, the macromolecular long-branched linking agent (number average molecular weight Mn of 7300) was obtained by centrifugation and drying.

[0070] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0071] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2707 was dissolved in chlorobenzene solution to prepare a 3% (w / w) rubber solution. Then, the rubber solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 32 minutes. Then, under nitrogen protection, 0.03g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 12MPa, and the temperature was raised to 105℃. After reacting for 9.5 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 85.7%).

[0072] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR): First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6.5% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced three times for purging. Next, 7.0g of a macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 82℃, a mixture of 0.09g of DCP and 240g of chlorobenzene was added. After reacting for 8.2 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (grafting rate 3.0%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0073] Example 3

[0074] (1) Preparation of macromolecular long-branched linking agents:

[0075] Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas four times. 1500g cyclohexane, 500g 1,3-butadiene, 3.5g THF, and 191mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 54℃ and the reaction was carried out for 64min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the BR homopolymer.

[0076] b. Preparation of macromolecular long-branched linking agent: First, nitrogen was purged four times in a 10L high-pressure reactor, and 4400g of cyclohexane was added. After heating to 84℃, 230g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 740rpm. Stirring was continued for 24min under nitrogen protection. Then, 40g of BR homopolymer and 1400g of cyclohexane were mixed and stirred for 40min to dissolve. Then, 150g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced and the pressure was maintained at 17MPa for 5.0hr. After the reaction was completed, the macromolecular long-branched linking agent (number average molecular weight Mn of 7800) was obtained by centrifugation and drying.

[0077] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0078] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2707 was dissolved in chlorobenzene solution to prepare a 4% (w / w) rubber solution. Then, the rubber solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 34 min. Then, under nitrogen protection, 0.05g of xylene solution containing Grubbs I catalyst (w / w, 7% (w / w)) was added. The hydrogen pressure in the reactor was increased to 12MPa, and the temperature was raised to 110℃. After reacting for 10 h, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 86.2%).

[0079] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR): First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 7.0% (w / w) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced four times for purging. Next, 8.0g of a macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 84℃, a mixture of 0.1g of DCP and 300g of chlorobenzene was added. After reacting for 8.4 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (grafting rate 3.2%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0080] Example 4

[0081] (1) Preparation of macromolecular long-branched linking agents:

[0082] Preparation of 1,3-butadiene homopolymer (BR): In a jacketed 10L stainless steel polymerization reactor, the system was purged with argon gas four times. 1700g cyclohexane, 500g 1,3-butadiene, 4.0g THF, and 210mmol n-butyllithium were added to the polymerization reactor sequentially. The temperature was raised to 56℃, and the reaction was carried out for 66min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the BR homopolymer.

[0083] Preparation of macromolecular long-branched linking agent: First, nitrogen was purged four times in a 10L high-pressure reactor, and 4600g of cyclohexane was added. After heating to 86℃, 260g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 760rpm. Stirring was continued for 26min under nitrogen protection. Then, 43g of BR homopolymer and 1600g of cyclohexane were mixed and stirred to dissolve for 44min. Then, 160g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced and the pressure was maintained at 18MPa for 5.3hr. After the reaction was completed, the macromolecular long-branched linking agent (number average molecular weight Mn of 8200) was obtained by centrifugation and drying.

[0084] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0085] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2707 was dissolved in chlorobenzene solution to prepare a 4.5% (w / w) rubber solution. Then, the rubber solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 36 min. Then, under nitrogen protection, 0.07g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 12MPa, and the temperature was raised to 113℃. After reacting for 10 h, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 87.1%).

[0086] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR): First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 8.0%. Then, the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen gas was introduced to purge four times. Next, 8.5g of a macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the reactor temperature reached 86℃, a mixture of 0.1g of DCP and 300g of chlorobenzene was added. After reacting for 8.6 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (grafting rate 3.5%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0087] Example 5

[0088] (1) Preparation of macromolecular long-branched linking agents:

[0089] Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerization reactor with a jacket, the system was purged with argon gas 5 times. 1900g cyclohexane, 500g 1,3-butadiene, 4.5g THF, and 230mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 58℃ and the reaction was carried out for 68min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the BR homopolymer.

[0090] b. Preparation of macromolecular long-branched linking agent: First, nitrogen was purged five times in a 10L high-pressure reactor, and 4800g of cyclohexane was added. After heating to 88℃, 280g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 780rpm. Stirring was continued for 28min under nitrogen protection. Then, 47g of BR homopolymer and 1800g of cyclohexane were mixed and stirred to dissolve for 47min. Then, 180g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst were added to the high-pressure reactor. Ethylene was introduced and the pressure was maintained at 19MPa for 5.6hr. After the reaction was completed, the macromolecular long-branched linking agent (number average molecular weight Mn of 8400) was obtained by centrifugation and drying.

[0091] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0092] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2707 was dissolved in chlorobenzene solution to prepare a 5.0% (w / w) rubber solution. Then, the rubber solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 38 min. Then, under nitrogen protection, 0.09g of xylene solution containing Grubbs I catalyst (w / w) was added. The hydrogen pressure in the reactor was increased to 13MPa, and the temperature was raised to 117℃. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 88.3%).

[0093] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR): First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 9.0% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced to purge five times. Next, 9.0g of a macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 88℃, a mixture of 0.11g of DCP and 350g of chlorobenzene was added. After reacting for 8.8 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (grafting rate 3.6%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0094] Example 6

[0095] (1) Preparation of macromolecular long-branched linking agents:

[0096] Preparation of 1,3-butadiene homopolymer (BR): In a jacketed 10L stainless steel polymerization reactor, the system was purged with argon gas 5 times. Then, 2000g cyclohexane, 500g 1,3-butadiene, 5.0g THF, and 260mmol n-butyllithium were added to the polymerization reactor in sequence. The temperature was raised to 60℃ and the reaction was carried out for 70min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the BR homopolymer.

[0097] b. Preparation of macromolecular long-branched linking agent: First, nitrogen was purged five times in a 10L high-pressure reactor. 5000g of cyclohexane was added, and the temperature was raised to 90℃. Then, 300g of ethylaluminoxane co-catalyst was added dropwise under uniform stirring at 800rpm. Stirring was continued for 30min under nitrogen protection. Subsequently, 50g of BR homopolymer and 2000g of cyclohexane were mixed and stirred to dissolve for 50min. Then, 200g of 1-hexene and 10g of 2,5-dicarboxypyrrole nickel dibromide main catalyst were added to the high-pressure reactor. Ethylene was introduced, and the pressure was maintained at 20MPa for 6.0hr. After the reaction was completed, the macromolecular long-branched linking agent (number average molecular weight Mn of 9000) was obtained by centrifugation and drying.

[0098] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0099] Preparation of hydrogenated nitrile butadiene rubber (HNBR): First, 100g of nitrile butadiene rubber 2707 was dissolved in chlorobenzene solution to prepare a 6.0% (w / w) rubber solution. Then, the rubber solution was added to a 10L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 40 minutes. Then, under nitrogen protection, 0.1g of xylene solution containing Grubbs I catalyst (w / w, 10% (w / w)) was added. The hydrogen pressure in the reactor was increased to 14MPa, and the temperature was raised to 120℃. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD = 89.4%).

[0100] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR): First, 200g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 9.0% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L jacketed stainless steel reactor, and nitrogen was introduced to purge five times. Next, 10.0g of a macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 90℃, a mixture of 0.12g of DCP and 400g of chlorobenzene was added. After reacting for 9.0 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70℃ oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (grafting rate 3.7%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0101] Comparative Example 1

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

[0103] Preparation of 1,3-butadiene homopolymer (BR): Same as in Example 1.

[0104] Preparation of macromolecular long-branched linking agent: Other conditions are the same as in Example 1, except that the amount of BR homopolymer added in the preparation of macromolecular long-branched linking agent is 20g. That is: first, nitrogen gas is purged three times in a 10L high-pressure reactor, 4000g of cyclohexane is added, the temperature is raised to 80℃, and 200g of methylaluminoxane co-catalyst is added dropwise under uniform stirring at 700rpm. Stirring is continued for 20min under nitrogen protection. Then, 20g of BR homopolymer and 1000g of cyclohexane are mixed and stirred to dissolve for 30min. Then, 100g of 1-octene and 10g of trans-bromophenyl (di(triphenylphosphine))nickel main catalyst are added to the high-pressure reactor. Ethylene is introduced and the pressure is maintained at 15MPa for 4.0hr. After the reaction is completed, the macromolecular long-branched linking agent a (number average molecular weight Mn is 6100) is obtained by centrifugation and drying.

[0105] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0106] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 1.

[0107] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (NBR): Other conditions were the same as in Example 1, except that no long-branched macromolecular linker was added during the preparation of the deformation-resistant, low-temperature-grade hydrogenated NBR. Instead, long-branched macromolecular linker a was added at a rate of 6.0 g. Specifically: First, 200 g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced three times for purging. Next, 6.0 g of long-branched macromolecular linker a was added to the reactor, stirred, and heated. When the reactor temperature reached 80°C, a mixture of 0.08 g of DCP and 200 g of chlorobenzene was added. After reacting for 8.0 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated NBR (grafting rate 2.4%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0108] Comparative Example 2

[0109] (1) Preparation of macromolecular long-branched linking agents:

[0110] Other conditions were the same as in Example 2, except that no BR homopolymer was added during the preparation of the deformation-resistant, low-temperature hydrogenated nitrile butadiene rubber. Instead, 35g of 1,3-butadiene was added. Specifically, nitrogen was first purged three times in a 10L high-pressure reactor, followed by the addition of 4200g of cyclohexane. After heating to 82°C, 210g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at 720rpm. Stirring continued for 22min under nitrogen protection. Then, 35g of 1,3-butadiene and 1200g of cyclohexane were mixed and stirred for 35min to dissolve. This mixture was then added to the high-pressure reactor along with 120g of 1-octene and 10g of trans-bromophenyl(di(triphenylphosphine))nickel main catalyst. Ethylene was introduced, and the reaction was carried out at 16MPa for 4.5hr. After the reaction was completed, the mixture was centrifuged, dried, and the macromolecular long-branched linker b (number average molecular weight Mn of 6400) was obtained.

[0111] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0112] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 2.

[0113] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (NBR): Other conditions were the same as in Example 2, except that no long-branched macromolecular linker was added during the preparation of the deformation-resistant, low-temperature-grade hydrogenated NBR. Instead, long-branched macromolecular linker b was added at a rate of 7.0 g. Specifically: First, 200 g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 6.5% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced three times for purging. Next, 7.0 g of long-branched macromolecular linker b was added to the reactor, stirred, and heated. When the reactor temperature reached 82°C, a mixture of 0.09 g of DCP and 240 g of chlorobenzene was added. After reacting for 8.2 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated NBR (grafting rate 2.7%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0114] Comparative Example 3

[0115] (1) Preparation of macromolecular long-branched linking agents:

[0116] Preparation of 1,3-butadiene homopolymer (BR): Same as in Example 3.

[0117] b. Preparation of macromolecular long-branched linking agent: Other conditions are the same as in Example 3, except that 1-octene is not added in the preparation of macromolecular long-branched linking agent, but 1-butene is added instead, with an addition amount of 150g. That is: first, nitrogen is purged into a 10L high-pressure reactor four times, 4400g of cyclohexane is added, and after heating to 84℃, 230g of methylaluminoxane co-catalyst is added dropwise under uniform stirring at 740rpm. Stirring is continued for 24min under nitrogen protection. Then, 40g of BR homopolymer and 1400g of cyclohexane are mixed and stirred to dissolve for 40min. Then, 150g of 1-butene and 10g of trans-bromophenyl(di(triphenylphosphine))nickel main catalyst are added to the high-pressure reactor. Ethylene is introduced and the pressure is maintained at 17MPa for 5.0hr. After the reaction is completed, the macromolecular long-branched linking agent c (number average molecular weight Mn is 6800) is obtained by centrifugation, drying.

[0118] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0119] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 3.

[0120] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (NBR): Other conditions were the same as in Example 3, except that no long-branched macromolecular linker was added during the preparation of the deformation-resistant, low-temperature-grade hydrogenated NBR. Instead, long-branched macromolecular linker c was added at a rate of 8.0 g. Specifically: First, 200 g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 7.0% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced four times for purging. Next, 8.0 g of long-branched macromolecular linker c was added to the reactor, stirred, and heated. When the reactor temperature reached 84°C, a mixture of 0.1 g of DCP and 300 g of chlorobenzene was added. After reacting for 8.4 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated NBR (grafting rate 3.0%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0121] Comparative Example 4

[0122] (1) Preparation of macromolecular long-branched linking agents:

[0123] Preparation of 1,3-butadiene homopolymer (BR): Same as in Example 4.

[0124] Preparation of macromolecular long-branched linking agent: Other conditions are the same as in Example 4, except that the amount of trans-bromophenyl(di(triphenylphosphine))nickel main catalyst added in the preparation of macromolecular long-branched linking agent is 5.0 g. That is: first, nitrogen gas is purged into a 10L high-pressure reactor four times, 4600 g of cyclohexane is added, and after heating to 86°C, 260 g of methylaluminoxane co-catalyst is added dropwise under uniform stirring at 760 rpm. Stirring is continued for 26 min under nitrogen protection. Then, 43 g of BR homopolymer and 1600 g of cyclohexane are mixed and stirred to dissolve for 44 min. Then, 160 g of 1-octene and 5.0 g of trans-bromophenyl(di(triphenylphosphine))nickel main catalyst are added to the high-pressure reactor. Ethylene is introduced and the pressure is maintained at 18 MPa for 5.3 hr. After the reaction is completed, the macromolecular long-branched linking agent d (number average molecular weight Mn is 4300) is obtained by centrifugation, drying.

[0125] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0126] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 4.

[0127] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (NBR): Other conditions were the same as in Example 4, except that no long-branched macromolecular linker was added during the preparation of the deformation-resistant, low-temperature-grade hydrogenated NBR. Instead, long-branched macromolecular linker d was added at a rate of 8.5 g. Specifically: First, 200 g of HNBR rubber was dissolved in a chlorobenzene solution to prepare an 8.0% (by mass) adhesive solution. Then, the adhesive solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced four times for purging. Next, 8.5 g of long-branched macromolecular linker d was added to the reactor, stirred, and heated. When the reactor temperature reached 86°C, a mixture of 0.1 g of DCP and 300 g of chlorobenzene was added. After reacting for 8.6 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated NBR (grafting rate 3.1%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0128] Comparative Example 5

[0129] (1) Preparation of macromolecular long-branched linking agents:

[0130] Preparation of 1,3-butadiene homopolymer (BR): Same as in Example 5.

[0131] b. Preparation of macromolecular long-branched linking agents: Same as in Example 5.

[0132] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0133] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Other conditions were the same as in Example 5, except that the amount of xylene solution (9% by mass) of Grubbs I catalyst added during the preparation of hydrogenated nitrile butadiene rubber (HNBR) was 0.2 g. Specifically: First, 100 g of nitrile butadiene rubber 2707 was dissolved in chlorobenzene solution to prepare a 5.0% by mass solution. Then, the solution was added to a 10 L high-pressure reactor, and nitrogen gas was introduced to remove air from the reactor. Next, hydrogen gas was used to purge the nitrogen from the reactor for 38 min. Then, under nitrogen protection, 0.2 g of xylene solution (9% by mass) of Grubbs I catalyst was added. The hydrogen pressure in the reactor was increased to 13 MPa, and the temperature was raised to 117 °C. After reacting for 11 h, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber b (hydrogenation degree HD = 92.3%).

[0134] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (HNBR) b: Other conditions were the same as in Example 5, except that HNBR rubber was not added during the preparation of the deformation-resistant, low-temperature-grade HNBR rubber. Instead, 200g of HNBR rubber b was added. Specifically, 200g of HNBR rubber b was first dissolved in a chlorobenzene solution to prepare a 9.0% (by mass) adhesive solution. This solution was then added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced five times for purging. Next, 9.0g of a macromolecular long-branched grafting agent was added to the reactor, and the mixture was stirred, heated, and when the reactor temperature reached 88°C, a mixture of 0.11g of DCP and 350g of chlorobenzene was added. After reacting for 8.8 hours, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (grafting rate 1.6%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0135] Comparative Example 6

[0136] (1) Preparation of macromolecular long-branched linking agents:

[0137] Preparation of 1,3-butadiene homopolymer (BR): Same as in Example 6.

[0138] b. Preparation of macromolecular long-branched linking agents: Same as in Example 6.

[0139] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile butadiene rubber:

[0140] Preparation of hydrogenated nitrile butadiene rubber (HNBR): Same as in Example 6.

[0141] Preparation of deformation-resistant, low-temperature-grade hydrogenated nitrile butadiene rubber (NBR): Other conditions were the same as in Example 6, except that the amount of macromolecular long-branched grafting agent added during the preparation of the deformation-resistant, low-temperature-grade hydrogenated NBR was 4.0 g. Specifically: First, 200 g of HNBR rubber was dissolved in a chlorobenzene solution to prepare a 9.0% (by mass) adhesive solution. Then, the adhesive solution was added to a 10 L stainless steel reactor with a jacket, and nitrogen was introduced five times for purging. Next, 4.0 g of macromolecular long-branched grafting agent was added to the reactor, stirred, and heated. When the reactor temperature reached 90 °C, a mixture of 0.12 g of DCP and 400 g of chlorobenzene was added. After reacting for 9.0 h, the mixture was flocculated with anhydrous ethanol, washed, and dried in a 70 °C oven to constant weight to obtain deformation-resistant, low-temperature-grade hydrogenated NBR (grafting rate 3.5%). Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0142] Table 1 Properties of Deformation Resistance and Low-Temperature Grade Hydrogenated Nitrile Rubber

[0143]

[0144]

[0145] As shown in Table 1, the deformation-resistant, low-temperature hydrogenated nitrile rubber of the present invention has small compression set and low glass transition temperature, making it suitable for oil well operations with a working temperature of -55℃ and a compression set of ≤28%.

[0146] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the present invention.

Claims

1. A process for the preparation of a low temperature, high strain hydrogenated nitrile rubber characterized in that, It comprises the following steps: (1) Preparation of macromolecular long-branching linking agent: a Preparation of 1,3-butadiene homopolymer BR: in a polymerization kettle, argon is introduced to replace the air, and then solvent, 1,3-butadiene, structure regulator and initiator 1 are sequentially added into the polymerization kettle, and the temperature is raised for reaction until no free monomer exists; the glue solution is obtained by wet coagulation and drying to obtain BR homopolymer; b Preparation of macromolecular long-branching linking agent: inert gas is introduced into the reaction kettle to replace the air, and then solvent is added, and the temperature is raised; under stirring, alkyl aluminoxane cocatalyst is added, and the stirring is continued under inert gas protection; then BR homopolymer and solution are mixed and dissolved under stirring until complete dissolution, and then long-chain α-olefin and nickel-based complex catalyst are added into the high-pressure reaction kettle, and at this time, ethylene is introduced for reaction; After the reaction is completed, centrifugal separation and drying are performed to obtain the macromolecular long-branching linking agent; the long-chain α-olefin is selected from one of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene and 1-dodecene; the mass ratio of the solvent, alkyl aluminoxane cocatalyst, BR homopolymer, solution, long-chain α-olefin, nickel-based complex catalyst is 400-500:20-30:3.0-5.0:100-200:10-20:1; (2) Preparation of deformation-resistant and low-temperature hydrogenated nitrile rubber: a Preparation of hydrogenated nitrile rubber HNBR: first, nitrile rubber is dissolved in chlorobenzene solution to prepare a glue solution, and then the glue solution is added into a reaction kettle to introduce inert gas to remove air in the reaction kettle; then, after the inert gas in the reaction kettle is removed by hydrogen, xylene solution of Grubbs I catalyst is added under nitrogen protection, and the system is pressurized and heated for reaction; the system is cooled, coagulated and vacuum dried to obtain HNBR rubber; wherein, based on 100 parts of nitrile rubber, the mass ratio of the nitrile rubber and Grubbs I catalyst is 100:0.02-0.1; b Preparation of deformation-resistant and low-temperature hydrogenated nitrile rubber: HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution, and then the glue solution is added into a reaction kettle to introduce inert gas to replace the air in the reaction kettle; then, macromolecular long-branching linking agent is added into the reaction kettle, and stirring, heating, addition of initiator 2 and mixed solution of chlorobenzene, reaction, flocculation with anhydrous ethanol, washing and drying are performed to obtain deformation-resistant and low-temperature hydrogenated nitrile rubber; the mass ratio of the HNBR rubber, macromolecular long-branching linking agent and chlorobenzene is 100:3-5:100-200; The number average molecular weight Mn of the macromolecular long-branching linking agent is 7000-9000.

2. The production method according to claim 1, characterized by, The nickel-based complex catalyst is selected from one of chloro(1-naphthyl)〔8-(diphenylphosphino)quinoline〕nickel, trans-bromophenyl(di(triphenylphosphine))nickel and 2,5-diformylpyrrole dibromide nickel.

3. The preparation method according to claim 1, characterized in that, The alkyl aluminoxane cocatalyst is selected from one of methyl aluminoxane MAO and ethyl aluminoxane EAO.

4. The method of claim 1, wherein, The initiator 1 is selected from one of n-butyl lithium, sec-butyl lithium, methyl butyl lithium, phenyl butyl lithium, naphthyl lithium, cyclohexyl lithium and dodecyl lithium.

5. 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, and is added in an amount of 0.01-0.1 parts based on 100 parts of the mass of the HNBR rubber.

6. The method of claim 1, wherein, The nitrile rubber is copolymerized by emulsion polymerization of 1,3-butadiene and acrylonitrile, and the acrylonitrile content of the nitrile rubber is 20wt%-42wt%.

7. 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.

8. 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.

9. The method of claim 1, wherein, In a of the step (1), the mass ratio of the solvent, 1,3-butadiene and the structure regulator is 2-4:1:0.005-0.

01.

10. The method of claim 1, wherein, The hydrogenation degree HD of the HNBR rubber is less than 90%.

11. The method of claim 1, wherein, In b of the step (2), the grafting rate of the deformation-resistant and low-temperature grade hydrogenated nitrile rubber is 2.9%-3.7%.

12. A deformation-resistant and low-temperature grade hydrogenated nitrile rubber prepared by the method of any one of claims 1-11.

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