Amine-terminated liquid hydrogenated nitrile rubber and preparation method thereof

Abstract

The invention relates to the technical field of rubber materials, in particular to amine-terminated liquid hydrogenated nitrile rubber and a preparation method thereof. The preparation method comprises the following steps: S1, carrying out nucleophilic substitution reaction on hydroxyl-terminated liquid hydrogenated butadiene-acrylonitrile rubber and benzene sulfonyl chloride to generate an intermediate A; and S2, carrying out nucleophilic substitution reaction on the intermediate A and diamine. According to the amine-terminated liquid hydrogenated butadiene-acrylonitrile rubber and the preparation method thereof provided by the invention, HHTBN is subjected to amination modification by virtue of a terminal group two-step modification method, hydroxyl groups at two ends are converted into benzenesulfonyl with very high reaction activity, then the benzenesulfonyl reacts with amine, and groups at two ends are converted into amino groups.

Description

Technical Field

[0001] The invention relates to the technical field of rubber materials, in particular to amine-terminated liquid hydrogenated nitrile rubber and a preparation method thereof. Background Art

[0002] Hydrogenated nitrile rubber (HNBR) is a highly saturated elastomer produced by selectively hydrogenating the unsaturated carbon-carbon double bonds in the backbone of nitrile rubber (NBR). It exhibits excellent chemical properties such as oil resistance, heat resistance, oxidation resistance, and corrosion resistance, while also possessing physical properties such as high strength, good wear resistance, and tear resistance. Due to its excellent overall performance, it is widely used in industries such as automotive, petrochemical, and aerospace.

[0003] Hydroxyl-terminated liquid hydrogenated nitrile rubber (HHTBN) is a liquid hydrogenated nitrile rubber with hydroxyl groups attached to both ends. It is widely used in adhesives, toughening agents, polyurethane elastomers, resistance materials, coatings, and more. Nowadays, many fields are increasingly demanding the comprehensive performance of materials, necessitating further modification of the rubber, such as polymerizing it with other monomers. While the terminal hydroxyl groups themselves possess a certain degree of activity, they still struggle to react effectively with many substances, or require very harsh conditions to react effectively, which presents a certain obstacle to the polymerization of this type of rubber. Therefore, terminal modification is necessary to convert the hydroxyl groups at both ends of the rubber into more active groups, making it easier for them to form good chemical bonds with other substances.

[0004] In the prior art, patent CN115477742A discloses a method for preparing end-group-modified polyoxalate. This method uses an end-capping agent during the reaction process. By using different end-capping agents, it is possible to regulate the properties of the polyester material and effectively control the degradation time of the polyoxalate. Patent CN114874120A discloses a method for preparing end-group-modified bismaleimide. By using a solution method, a bismaleimide raw material and 4-chloromethylstyrene are subjected to a heating reaction under the catalysis of a catalyst to obtain a modified product. This method has contributed to broadening the application range of bismaleimide. Patent CN117777443A discloses a method for end-group modification using a continuous reaction extrusion process, which produces an end-group-modified thermoplastic polyimide. This method can effectively modify the end groups without the addition of a catalyst, but this method is more likely to cause some defects in the produced material during the extrusion process. Summary of the Invention

[0005] The present invention aims to provide an amine-terminated liquid hydrogenated nitrile rubber and a preparation method thereof. The amine-terminated liquid hydrogenated nitrile rubber is first reacted with benzenesulfonyl chloride to convert the hydroxyl groups at both ends of the nitrile rubber into benzenesulfonyl groups. The intermediate obtained by the reaction is purified and then reacted with the diamine to finally prepare the amine-terminated liquid hydrogenated nitrile rubber. The amine groups at both ends of the nitrile rubber have greater activity than the hydroxyl groups and are more easily reacted with other chemical substances. The amine-terminated liquid hydrogenated nitrile rubber can be used to further prepare hydrogenated nitrile materials with excellent comprehensive properties to meet the needs of various fields.

[0006] Based on this, the present invention has the following technical solutions: In a first aspect, the present invention provides a method for preparing an amine-terminated liquid hydrogenated nitrile rubber, comprising: S1: a nucleophilic substitution reaction is carried out between the hydroxyl-terminated liquid hydrogenated nitrile rubber and benzenesulfonyl chloride to generate intermediate A; S2: subjecting the intermediate A to a nucleophilic substitution reaction with a diamine.

[0007] The present invention provides a new approach to amination modification, namely, an indirect conversion method involving two-step end group modification, whereby the terminal hydroxyl group of the reactant is first converted into a highly reactive phenylsulfonyl group and then into an amino group. This reaction method is simple to operate and operates under mild reaction conditions, eliminating the complex and demanding reaction conditions of direct amination methods and providing a new approach to end group modification. The resulting amine-terminated liquid hydrogenated nitrile butadiene rubber (hereinafter referred to as "HATBN") can be used for further reactions with other substances, such as chain extension and cross-linking reactions, to form polymers with desired properties. This invention is of great significance in the fields of hydrogenated nitrile butadiene rubber and liquid rubber.

[0008] In the present invention, the intermediate A is a liquid hydrogenated nitrile rubber with benzenesulfonyl groups attached to both ends.

[0009] Preferably, the diamine includes one or more of 1,3-propylenediamine, 1,4-butylenediamine, 1,6-hexanediamine, 1,10-decanediamine and p-phenylenediamine.

[0010] Preferably, the degree of hydrogenation of the hydroxyl-terminated liquid hydrogenated nitrile rubber is 90% to 99.8%, and the acrylonitrile content is 16% to 40%.

[0011] Preferably, in S1, the molar ratio of the hydroxyl group of the hydroxyl-terminated liquid hydrogenated nitrile rubber to the sulfonyl chloride group of benzenesulfonyl chloride is 1:(1-2).

[0012] Preferably, S1 comprises: conducting a nucleophilic substitution reaction of hydroxyl-terminated liquid hydrogenated nitrile rubber, an acid binding agent and benzenesulfonyl chloride in an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa to generate intermediate A.

[0013] Preferably, the inert gas includes nitrogen, argon, etc.

[0014] More preferably, the temperature of the nucleophilic substitution reaction in S1 is 20-30°C.

[0015] Preferably, the acid binding agent is one or more of triethylamine, pyridine, triethanolamine, and tetrabutylammonium bromide.

[0016] More preferably, the molar ratio of benzenesulfonyl chloride to triethylamine is (1.2-2):1.2.

[0017] Preferably, in S2, the molar ratio of the intermediate A to the diamine is 1:(2-2.5).

[0018] Preferably, S2 comprises: conducting a nucleophilic substitution reaction between the intermediate A and a diamine in an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa.

[0019] Preferably, the preparation method of the amine-terminated liquid hydrogenated nitrile rubber comprises: S1: dissolving hydroxyl-terminated liquid hydrogenated nitrile rubber in a first solvent to obtain a first adhesive solution; mixing the first adhesive solution, an acid-binding agent, and benzenesulfonyl chloride, and performing a nucleophilic substitution reaction under an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa to obtain a first reaction solution; and then sequentially centrifuging, rotary evaporating, washing, and drying the first reaction solution to produce an intermediate A; S2: dissolving the intermediate A in a second solvent to obtain a second adhesive solution; mixing the second adhesive solution with a diamine, and performing a nucleophilic substitution reaction under an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa to obtain a second reaction solution; and then sequentially centrifuging, rotary evaporating, washing, and drying the second reaction solution to produce an amine-terminated liquid hydrogenated nitrile rubber; Preferably, the first solvent and the second solvent each independently, identically or differently, comprise one or more of dichloromethane, tetrahydrofuran, ethyl acetate and n-heptane.

[0020] Preferably, the concentration of the first glue solution is 5% to 40%, more preferably 7% to 20%.

[0021] Preferably, the concentration of the second glue is 7% to 20%.

[0022] Preferably, the preparation method of the amine-terminated liquid hydrogenated nitrile rubber comprises: S1: dissolving hydroxyl-terminated liquid hydrogenated nitrile rubber in tetrahydrofuran to obtain a first glue solution; mixing the first glue solution, triethylamine, and benzenesulfonyl chloride, and conducting a nucleophilic substitution reaction under a nitrogen atmosphere at 20-30° C. and 1.5-2.5 MPa to obtain a first reaction solution; and then sequentially centrifuging, rotary evaporating, washing, and drying the first reaction solution to produce an intermediate A; S2: dissolving the intermediate A in dichloromethane or tetrahydrofuran to obtain a second glue solution; mixing the second glue solution with a diamine, and performing a nucleophilic substitution reaction under a nitrogen atmosphere at 20-30° C. and 1.5-2.5 MPa to obtain a second reaction solution; and then sequentially centrifuging, rotary evaporating, washing, and drying the second reaction solution to produce an amine-terminated liquid hydrogenated nitrile rubber; In a second aspect, the present invention provides an amine-terminated liquid hydrogenated nitrile rubber, which is prepared by the above-mentioned preparation method of the amine-terminated liquid hydrogenated nitrile rubber.

[0023] The present invention provides an amine-terminated liquid hydrogenated nitrile rubber and a preparation method thereof. HHTBN is modified by amination via a two-step end group modification process. The hydroxyl groups at both ends are first converted to highly reactive benzenesulfonyl groups, which are then reacted with amines to convert the end groups into amino groups. This method requires no catalyst, operates under simple, mild reaction conditions, and is easy to execute. It addresses the challenging and demanding requirements for direct conversion of hydroxyl groups to amino groups, thus broadening the application areas of rubber modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 The infrared spectra of HHTBN and a series of amine-terminated liquid hydrogenated nitrile rubbers provided by the present invention.

[0026] Figure 2 The present invention provides HHTBN, intermediate A and a series of amine-terminated liquid hydrogenated nitrile rubber nuclear magnetic hydrogen spectra (400MHz, CDCl3).

[0027] Figure 3 TG curves and DTG curves of HHTBN and a series of HATBN provided by the present invention.

[0028] Figure 4 The DTG curves of HHTBN and a series of HATBN provided by the present invention.

[0029] Figure 5 This is a statistical line graph of the thermal decomposition temperature of HHTBN and a series of HATBN provided by the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0031] Unless otherwise specified, the various raw materials used in the examples and comparative examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0032] Example 1 This embodiment provides a method for preparing amine-terminated liquid hydrogenated nitrile rubber, comprising the following steps: (1) 27.9 g of HHTBN with a hydrogenation degree of 99.8% and an acrylonitrile content of 16% was prepared into a 10% HHTBN gel solution using tetrahydrofuran as a solvent. 279 g of the gel solution and 1.28 g of benzenesulfonyl chloride were then added to a clean, dry 500 ml three-necked flask. The mixture was stirred at room temperature under nitrogen for 6 h. After the reaction was complete, the intermediate A was obtained by centrifugation, rotary evaporation, and washing. The product was named HLNBR-BSO.

[0033] (2) Using dichloromethane as the solvent, the intermediate A was prepared into a 10% by weight gel solution. 93 g of the gel solution and 0.15 g of 1,3-propylenediamine were then added to a clean, dry 250 ml three-necked flask. The mixture was stirred at room temperature under nitrogen for 24 h. After the reaction was complete, the mixture was centrifuged, rotary evaporated, washed, and dried to obtain the reactant B, which was named HAmTBN-P. Its molecular weight, glass transition temperature, and thermal decomposition temperature were determined.

[0034] Example 2 This embodiment provides a method for preparing amine-terminated liquid hydrogenated nitrile rubber, comprising the following steps: (1) 27.9 g of HHTBN with a hydrogenation degree of 99.8% and an acrylonitrile content of 16% was prepared into a 10% HHTBN gel solution using tetrahydrofuran as a solvent. 279 g of the gel solution and 1.28 g of benzenesulfonyl chloride were then added to a clean, dry 500 ml three-necked flask. The mixture was stirred at room temperature under nitrogen for 6 h. After the reaction was complete, the mixture was centrifuged, rotary evaporated, and washed to obtain intermediate A.

[0035] (2) Using tetrahydrofuran as solvent, the intermediate A was prepared into a 10% by weight gel solution. 93 g of the gel solution and 0.18 g of 1,4-butanediamine were then added to a clean, dry 250 ml three-necked flask. The mixture was stirred at room temperature under nitrogen for 24 h. After the reaction was complete, the mixture was centrifuged, rotary evaporated, washed, and dried to obtain the reactant C, which was named HAmTBN-B.

[0036] The molecular weight, glass transition temperature and thermal decomposition temperature were determined.

[0037] Example 3 This embodiment provides a method for preparing amine-terminated liquid hydrogenated nitrile rubber, comprising the following steps: (1) 27.9 g of HHTBN with a hydrogenation degree of 99.8% and an acrylonitrile content of 16% was prepared into a 10% HHTBN gel solution using tetrahydrofuran as a solvent. 279 g of the gel solution and 1.28 g of benzenesulfonyl chloride were then added to a clean, dry 500 ml three-necked flask. The mixture was stirred at room temperature under nitrogen for 6 h. After the reaction was complete, the mixture was centrifuged, rotary evaporated, and washed to obtain intermediate A.

[0038] (2) Using tetrahydrofuran as solvent, the intermediate A was prepared into a 10% by weight gel solution. 93 g of the gel solution and 0.24 g of 1,6-hexanediamine were then added to a clean, dry 250 ml three-necked flask. The mixture was stirred at room temperature under nitrogen for 24 h. After the reaction was complete, the product was centrifuged, rotary evaporated, washed, and dried to obtain the reactant D, which was named HAmTBN-H. Its molecular weight, glass transition temperature, and thermal decomposition temperature were determined.

[0039] Example 4 This embodiment provides a method for preparing amine-terminated liquid hydrogenated nitrile rubber, comprising the following steps: (1) 27.9 g of HHTBN with a hydrogenation degree of 99.8% and an acrylonitrile content of 16% was prepared into a 10% HHTBN gel solution using tetrahydrofuran as a solvent. 279 g of the gel solution and 1.28 g of benzenesulfonyl chloride were then added to a clean, dry 500 ml three-necked flask. The mixture was stirred at room temperature under nitrogen for 6 h. After the reaction was complete, the mixture was centrifuged, rotary evaporated, and washed to obtain intermediate A.

[0040] (2) Using tetrahydrofuran as solvent, the intermediate A was prepared into a 10% by weight gel solution. 93 g of the gel solution and 0.35 g of 1,10-decanediamine were then added to a clean, dry 250 ml three-necked flask. The mixture was reacted at room temperature for 24 h under nitrogen. After the reaction was complete, the mixture was centrifuged, rotary evaporated, washed, and dried to obtain the reactant E, which was named HAmTBN-D.

[0041] The molecular weight, glass transition temperature and thermal decomposition temperature were determined.

[0042] Example 5 This embodiment provides a method for preparing amine-terminated liquid hydrogenated nitrile rubber. The only difference between this embodiment and Examples 1 to 4 is that the fatty diamine in Examples 1 to 4 is replaced by an equimolar amount of p-phenylenediamine. After the same reaction steps, reactant F is obtained, and the product is named HAmTBN-M.

[0043] The infrared spectra of HHTBN and a series of amine-terminated liquid hydrogenated nitrile rubbers are shown in Figure 1 .

[0044] HHTBN, intermediate A and a series of amine-terminated liquid hydrogenated nitrile rubber NMR hydrogen spectra (400MHz, CDCl3) are shown in Figure 2 .

[0045] Test example The testing methods for the molecular weight and glass transition temperature of the above examples are as follows: Molecular weight test method: Molecular weight tests were performed using a Waters 1515 gel permeation chromatograph (GPC). 5 mg of each of reactants B to E was weighed using an analytical balance and dissolved in 1 ml of THF until a completely clear solution was formed. The solution was then filtered using a syringe and a 0.45 μm nylon filter to obtain the test sample. The standard sample was polystyrene (PS). The flow rate during the test was 1 ml / min.

[0046] Glass transition temperature (Tg) test method: A MicroCal PEAQ-ITC differential scanning calorimeter was used, with a test temperature range of -80°C to 100°C. Test subjects included HHTBN and reactants B to E. The test procedure was as follows: the temperature was first raised from room temperature to 100°C, held for 5 minutes to eliminate thermal stress in the material, then lowered to 100°C, held for 5 minutes, and then raised back to 100°C at a ramp rate of 10°C / min.

[0047] Thermal decomposition temperature (T5%) test method: The samples were tested and analyzed using a Mettler Toledo TG / DSC instrument. The test temperature range was 30°C to 600°C. The test subjects were HHTBN and reactants B to E. The test procedure was to increase the sample temperature from 30°C to 600°C at a rate of 10°C / min. The test was conducted under a protective atmosphere of N2.

[0048] The TG and DTG curves of HHTBN and a series of HABN are shown in Figure 3 .

[0049] The DTG curves of HHTBN and a series of HABN are shown in Figure 4 .

[0050] The thermal decomposition temperature line graphs of HHTBN and a series of HATBN are shown in Figure 5 .

[0051] After testing, the results are shown in Table 1: Table 1 Test results of HHTBN and liquid hydrogenated nitrile rubber with different terminal amines

[0052] Note: T 5% The temperature at which the rubber loses 5% of its mass in the thermogravimetric test is the thermal decomposition temperature.

[0053] The data in Table 1 show that the molecular weight of the hydrogenated nitrile materials after end group modification has been improved to a certain extent. For Examples 1 to 4, the molecular weight is positively correlated with the size of the rubber end group. This indicates that several fatty diamines have been successfully connected to the two ends of the rubber through the nucleophilic substitution reaction of the end group two-step modification method, replacing the hydroxyl groups at both ends of HHTBN. The Tg of the hydrogenated nitrile rubber after end group modification is slightly improved relative to the Tg of HHTBN. Since the polarity of the amine groups at both ends of the modified rubber is greater than the polarity of the hydroxyl groups at both ends of the rubber before modification, this will lead to an increase in the Tg of the modified rubber. For Example 5, its molecular weight is greater than that of Examples 1 and 2 and less than that of Examples 3 and 4. First, by comparing the molecular weights of their end groups, it can be seen that: Example 4> Example 3> Example 5> Example 2> Example 1, which is consistent with the molecular weight relationship of the corresponding amine-terminated liquid hydrogenated nitrile rubber, further illustrating that the molecular weight of the rubber is positively correlated with the size of its end group. Analysis of the data from Examples 1-4 reveals that the Tg values of Examples 1-4 show a gradually decreasing trend. In Examples 1-4, the chain length of the diamine reacting with Intermediate A gradually increases, resulting in increasingly longer chain lengths of the groups at the ends of the resulting reactants. This increases the flexibility of the rubber's molecular chain, a key factor in the lowering of the rubber's Tg. Since the polarity of HHTBN is increased after modification, the Tg values of Examples 1-4 are all greater than those of HHTBN. Example 5 has a higher Tg value than both HHTBN and Examples 1-4. This is because the introduction of p-phenylenediamine, a rigid benzene ring structure, increases the rigidity of the rubber chain structure. Furthermore, the rigid groups at the end groups may also restrict the movement of the entire molecular chain. Furthermore, the rubber chain length of Example 5 is shorter than that of Examples 1-4, all of which are significant factors contributing to the higher Tg value of Example 5.

[0054] After amination modification, the thermal decomposition temperature of the rubber is lower than that of HHTBN. After amination modification, the CO bond in HHTBN is transformed into a CN bond. The bond energy of the CN bond is lower than that of the CO bond. Therefore, after modification, the bond energy inside the rubber decreases, resulting in a decrease in the thermal decomposition temperature. As the chain length of the fatty diamine participating in the reaction increases, the thermal decomposition temperature of HAmTBN shows a trend of first increasing and then decreasing. As the molecular chain length of the fatty diamine participating in the reaction increases, the molecular chain flexibility of the rubber increases. The increase in molecular chain flexibility is beneficial to improving the thermal stability of the rubber, but at the same time, the bond energy inside the rubber decreases. The decrease in bond energy will lead to a decrease in thermal stability. Therefore, it may be because when the molecular chain length is shorter, When the rubber chain is modified with p-phenylenediamine, the increased flexibility of the rubber molecular chain outweighs the decreased bond energy, resulting in an increase in the thermal decomposition temperature in Examples 1 through 3 with increasing chain length of the participating fatty diamine. However, when HHTBN is modified with the longer-chain 1,10-decanediamine, the thermal decomposition temperature of the resulting HAmTBN-D does not continue to rise, but instead decreases compared to that of HAmTBN-H. This may be because the increased flexibility brought about by the increased molecular chain length is insufficient to compensate for the decreased internal bond energy, leading to decreased thermal stability. In Example 5, while the introduction of benzene rings theoretically enhances rubber stability and is a favorable factor in raising the thermal decomposition temperature, TG testing revealed a thermal decomposition temperature of 340.4°C, only slightly higher than that of Example 1. This may be because the introduction of p-phenylenediamine makes the overall material structurally too rigid, making it more susceptible to breakage when heated, resulting in a lower-than-expected thermal decomposition temperature. It may also be related to the varying reaction efficiencies of the diamines with the intermediates.

[0055] The above experimental results show that the amination modification of HHTBN with a fatty diamine of appropriate chain length can significantly enhance the thermal stability of the rubber, and can also reduce the Tg value of the rubber after amination modification by increasing the chain length of the fatty diamine participating in the reaction, so that the rubber maintains its original excellent low-temperature resistance.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing amine-terminated liquid hydrogenated nitrile rubber, characterized in that: include: S1: a nucleophilic substitution reaction is carried out between the hydroxyl-terminated liquid hydrogenated nitrile rubber and benzenesulfonyl chloride to generate intermediate A; S2: subjecting the intermediate A to a nucleophilic substitution reaction with a diamine.

2. The method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to claim 1, wherein The diamine includes one or more of 1,3-propylenediamine, 1,4-butylenediamine, 1,6-hexanediamine, 1,10-decanediamine and p-phenylenediamine.

3. The method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to claim 1 or 2, wherein: The hydrogenation degree of the hydroxyl-terminated liquid hydrogenated nitrile rubber is 90% to 99.8%, and the acrylonitrile content is 16% to 40%.

4. The method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to any one of claims 1 to 3, wherein In S1, the molar ratio of the hydroxyl group of the hydroxyl-terminated liquid hydrogenated nitrile rubber to the sulfonyl chloride group of benzenesulfonyl chloride is 1:(1-2).

5. The method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to any one of claims 1 to 4, wherein: S1 includes: The hydroxy-terminated liquid hydrogenated nitrile rubber, an acid-binding agent and benzenesulfonyl chloride are subjected to a nucleophilic substitution reaction in an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa to generate an intermediate A.

6. The method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to claim 5, wherein: The acid binding agent is one or more of triethylamine, pyridine, triethanolamine, and tetrabutylammonium bromide; preferably, the molar ratio of benzenesulfonyl chloride to triethylamine is (1.2~2):1.

2.

7. The method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to any one of claims 1 to 6, wherein: In S2, the molar ratio of the intermediate A to the diamine is 1:(2-2.5).

8. The method for preparing an amine-terminated liquid hydrogenated nitrile rubber according to any one of claims 1 to 7, wherein S2 include: The intermediate A is reacted with diamine in an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa for a nucleophilic substitution reaction.

9. The method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to any one of claims 1 to 8, wherein: include: S1: dissolving hydroxyl-terminated liquid hydrogenated nitrile rubber in a first solvent to obtain a first adhesive solution; mixing the first adhesive solution, an acid-binding agent, and benzenesulfonyl chloride, and performing a nucleophilic substitution reaction under an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa to obtain a first reaction solution; and then sequentially centrifuging, rotary evaporating, washing, and drying the first reaction solution to produce an intermediate A; S2: dissolving the intermediate A in a second solvent to obtain a second adhesive solution; mixing the second adhesive solution with a diamine, and performing a nucleophilic substitution reaction under an inert gas atmosphere at 20-80° C. and 1.5-2.5 MPa to obtain a second reaction solution; and then sequentially centrifuging, rotary evaporating, washing, and drying the second reaction solution to produce an amine-terminated liquid hydrogenated nitrile rubber; Preferably, the first solvent and the second solvent each independently, identically or differently, comprise one or more of dichloromethane, tetrahydrofuran, ethyl acetate and n-heptane.

10. An amine-terminated liquid hydrogenated nitrile rubber, characterized in that: The rubber is prepared by the method for preparing the amine-terminated liquid hydrogenated nitrile rubber according to any one of claims 1 to 9.

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