Cross-linked elastomer composition, cross-linked elastomer and preparation method of cross-linked elastomer

Abstract

The invention relates to the technical field of rubber materials, and discloses a composition of a cross-linked elastomer, the cross-linked elastomer and a preparation method of the cross-linked elastomer, and the composition comprises epoxidized nitrile rubber, polybasic acid modified filler and a transesterification catalyst; relative to 100 parts by weight of epoxidized nitrile rubber, the content of the polyacid modified filler is 8-100 parts by weight, and the content of the ester exchange catalyst is 0.5-10 parts by weight; the grafting rate of carboxyl in the polybasic acid modified filler is 10-70%. A cross-linked elastomer prepared from the composition has high mechanical properties, and also has excellent dynamic mechanical properties and repeatable processability.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber materials, and in particular, to a composition of a crosslinked elastomer, the crosslinked elastomer, and a preparation method thereof. Background Art

[0002] Due to its unique high elasticity, rubber materials are widely used in fields such as tires, shock-absorbing bearings, conveyor belts, and aerospace, and are an important strategic resource. An important prerequisite for rubber materials to obtain high elasticity is the crosslinking (also known as vulcanization) of rubber. That is to say, rubber materials must transform the linear chain structure into a three-dimensional network structure through crosslinking before they can be transformed into useful rubber products. However, the crosslinking methods widely used in the current rubber industry (mainly sulfur crosslinking and peroxide crosslinking) have the following several inevitable inherent problems: (1) Toxic substances will inevitably be used in the crosslinking system; (2) Toxic and unpleasant "vulcanization fumes" will be released during the crosslinking reaction process. On the one hand, this will cause great harm to human health; in addition, the unpleasant smell remaining on the rubber products will also affect the user experience; (3) The recycling of waste rubber products is very difficult, bringing serious black pollution problems. At the same time, the recycling of waste rubber products is very difficult, causing serious "black pollution". Currently, the annual global production of waste rubber is about 30 million tons, most of which are incinerated to recover heat energy or ground into rubber powder. Another part of the waste rubber can be used to prepare reclaimed rubber, that is, by opening the carbon-carbon and carbon-sulfur crosslinking bonds in the crosslinking bonds of waste rubber and destroying the network structure therein to obtain reclaimed rubber. However, traditional desulfurization technologies do not have selectivity in opening crosslinking bonds, and at the same time, the rubber molecular chains will also be damaged, resulting in poor performance of reclaimed rubber; in addition, the desulfurization process also has problems such as high energy consumption and serious pollution.

[0003] Therefore, there is an urgent need for a crosslinked elastomer with high mechanical properties. At the same time, the crosslinked elastomer also has excellent dynamic mechanical properties and repeatable processing properties. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems of poor dynamic mechanical properties and repeatable processing properties of the crosslinked elastomers in the prior art, and to provide a composition of a crosslinked elastomer, the crosslinked elastomer, and a preparation method thereof. The composition of the crosslinked elastomer contains epoxidized nitrile rubber and polyacid-modified filler, and the prepared crosslinked elastomer has high mechanical properties, and at the same time also has excellent dynamic mechanical properties and repeatable processing properties.

[0005] To achieve the above purpose, the first aspect of the present invention provides a composition of a crosslinked elastomer, wherein the composition includes epoxidized nitrile rubber, polyacid-modified filler, and transesterification catalyst;

[0006] Based on 100 parts by weight of epoxidized nitrile rubber, the content of the polyacid-modified filler is 8 - 100 parts by weight, and the transesterification catalyst is 0.5 - 10 parts by weight;

[0007] The grafting rate of carboxyl groups in the polyacid-modified filler is 10 - 70%.

[0008] The second aspect of the present invention provides a crosslinked elastomer, wherein the crosslinked elastomer is prepared by mixing and vulcanizing the composition of the above crosslinked elastomer.

[0009] The third aspect of the present invention provides a method for preparing the above crosslinked elastomer, wherein the method includes: mixing and vulcanizing epoxidized nitrile rubber with the polyacid-modified filler to obtain the crosslinked elastomer;

[0010] The grafting rate of carboxyl groups in the polyacid-modified filler is 10 - 70%.

[0011] Through the above technical solutions, the composition of the crosslinked elastomer, the crosslinked elastomer and its preparation method of the present invention have the following beneficial effects:

[0012] In the composition of the crosslinked elastomer of the present invention, the epoxy groups of the epoxidized nitrile rubber and the carboxyl groups in the polyacid-modified filler generate a dynamic crosslinked structure. When the epoxidized nitrile rubber and the polyacid-modified filler are used in specific amounts, and when the grafting rate of carboxyl groups in the polyacid-modified filler is within a specific range, the prepared crosslinked elastomer has high mechanical properties, excellent dynamic mechanical properties and repeatable processing properties. Detailed Embodiments

[0013] In the ranges disclosed herein, the endpoints and any values are not limited to the exact range or value, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0014] The first aspect of the present invention provides a composition of a crosslinked elastomer, wherein the composition includes epoxidized nitrile rubber, a polyacid-modified filler and a transesterification catalyst;

[0015] Based on 100 parts by weight of epoxidized nitrile rubber, the content of the polyacid-modified filler is 8 - 100 parts by weight, and the transesterification catalyst is 0.5 - 10 parts by weight;

[0016] The grafting rate of carboxyl groups in the polyacid-modified filler is 10 - 70%.

[0017] In the present invention, an epoxy group of the epoxidized nitrile rubber and a carboxyl group in the polyacid-modified filler generate a dynamic crosslinked structure. When the epoxidized nitrile rubber and the polyacid-modified filler are used in specific amounts, and when the grafting rate of the carboxyl group in the polyacid-modified filler is within a specific range, the obtained crosslinked elastomer has high mechanical properties, excellent dynamic mechanical properties, and repeatable processing properties.

[0018] In the present invention, the grafting rate of the carboxyl group in the polyacid-modified filler is measured by a thermogravimetric method, in a nitrogen atmosphere, at a temperature of 40 - 800 °C, and a heating rate of 10 °C / min. In the present invention, the grafting rate of the carboxyl group in the polyacid-modified filler refers to the grafting rate of the polyacid modifier on the filler.

[0019] Furthermore, relative to 100 parts by weight of the epoxidized nitrile rubber, the content of the polyacid-modified filler is 30 - 80 parts by weight, and the transesterification catalyst is 0.5 - 3 parts by weight.

[0020] Furthermore, the grafting rate of the carboxyl group in the polyacid-modified filler is 20 - 45%.

[0021] According to the present invention, the epoxidation degree of the epoxidized nitrile rubber is 10 - 80%.

[0022] In the present invention, when the epoxidation degree of the epoxidized nitrile rubber meets the above range, it is beneficial to improve the reprocessability of the crosslinked elastomer, and good wet skid resistance and low rolling resistance can be obtained.

[0023] Furthermore, the epoxidation degree of the epoxidized nitrile rubber is 25 - 60%.

[0024] According to the present invention, the acrylonitrile content in the epoxidized nitrile rubber is 10 - 50 wt%.

[0025] Furthermore, the acrylonitrile content in the epoxidized nitrile rubber is 20 - 35 wt%.

[0026] According to the present invention, the epoxidized nitrile rubber is epoxidized hydrogenated nitrile rubber.

[0027] According to the present invention, the double bond content in the epoxidized hydrogenated nitrile rubber is 0.1 wt% - 20 wt%.

[0028] Furthermore, the double bond content in the epoxidized hydrogenated nitrile rubber is 0.5 wt% - 5 wt%.

[0029] According to the present invention, the polyacid-modified filler is selected from at least one of polyacid-modified carbon black, polyacid-modified silica, polyacid-modified montmorillonite, polyacid-modified kaolin, polyacid-modified mica, and polyacid-modified talc.

[0030] In the present invention, when the above-mentioned polyacid-modified filler is used, it has more crosslinkable groups, thereby improving the reprocessability and mechanical properties of the crosslinked elastomer.

[0031] Further, the polyacid-modified filler is a combination of polyacid-modified silica and at least one selected from polyacid-modified carbon black, polyacid-modified montmorillonite, polyacid-modified kaolin, polyacid-modified mica, and polyacid-modified talc powder.

[0032] In the present invention, when the above-mentioned polyacid-modified filler combinations are used, a hybrid reinforcing network structure can be formed between the fillers, increasing the contact area between the fillers and the base rubber, thereby improving the reprocessability and mechanical properties of the crosslinked elastomer.

[0033] According to the present invention, based on the total weight of the polyacid-modified filler, the content of the polyacid-modified silica is 5-100 wt%.

[0034] In the present invention, when the content of the polyacid-modified silica meets the above range, a better hybrid reinforcing network can be formed between the polyacid-modified silica and other polyacid-modified fillers, enabling the crosslinked elastomer to have better static and dynamic mechanical properties and a faster stress relaxation rate at high temperatures.

[0035] Further, based on the total weight of the polyacid-modified filler, the content of the polyacid-modified silica is 40-95 wt%.

[0036] In the present invention, there is no special limitation on the selection of the transesterification catalyst, and it can be a conventional transesterification catalyst in the art. Preferably, the transesterification catalyst is selected from at least one of zinc acetate, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

[0037] According to the present invention, the composition further includes an antioxidant.

[0038] In the present invention, there is no special limitation on the selection of the antioxidant, and it can be a conventional antioxidant in the art. Preferably, the antioxidant is selected from at least one of N,N'-diphenyl-p-phenylenediamine (antioxidant H), N-isopropyl-N'-phenyl-p-phenylenediamine (antioxidant 4010NA), 2,2,4-trimethyl-1,2-dihydroquinoline polymer (antioxidant RD), 9,9-dimethylacridine (antioxidant BLE), 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (antioxidant 2246), N-phenyl-2-naphthylamine (antioxidant D), and N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine (antioxidant 4020).

[0039] According to the present invention, relative to 100 parts by weight of epoxidized nitrile rubber, the antioxidant is 0.06 - 4 parts by weight.

[0040] Further, relative to 100 parts by weight of epoxidized nitrile rubber, the antioxidant is 1 - 3.5 parts by weight.

[0041] According to the present invention, the composition further comprises a plasticizer.

[0042] In the present invention, there is no special limitation on the selection of the plasticizer, and it can be a conventional plasticizer in the art. Preferably, the plasticizer is selected from at least one of naphthenic oil, aromatic oil, paraffin wax, coumarone resin, and petrolatum.

[0043] According to the present invention, relative to 100 parts by weight of epoxidized nitrile rubber, the plasticizer is 0.1 - 20 parts by weight.

[0044] Further, relative to 100 parts by weight of epoxidized nitrile rubber, the plasticizer is 3 - 8 parts by weight.

[0045] In the second aspect of the present invention, a crosslinked elastomer is provided, wherein the crosslinked elastomer is prepared by kneading and vulcanizing the composition of the above crosslinked elastomer.

[0046] According to the present invention, the tensile strength of the crosslinked elastomer is greater than or equal to 20 MPa.

[0047] Further, the tensile strength of the crosslinked elastomer is greater than or equal to 25 MPa.

[0048] According to the present invention, the elongation at break of the crosslinked elastomer is 400 - 800%.

[0049] Further, the elongation at break of the crosslinked elastomer is 400 - 700%.

[0050] According to the present invention, at 140 °C, the time for the crosslinked elastomer to stress-relax to 37% of the original stress is less than or equal to 70 min.

[0051] In the present invention, when the stress relaxation time of the crosslinked elastomer satisfies the above range, it indicates that the crosslinked elastomer has good reprocessability.

[0052] Further, at 140 °C, the time for the crosslinked elastomer to stress-relax to 37% of the original stress is less than or equal to 60 min.

[0053] According to the present invention, at 160 °C, the time for the crosslinked elastomer to stress-relax to 37% of the original stress is less than or equal to 30 min.

[0054] Further, at 160 °C, the time for the stress of the crosslinked elastomer to relax to 37% of the original stress is less than or equal to 20 min.

[0055] According to the present invention, the loss factor of the crosslinked elastomer at 0 °C is greater than or equal to 1.2.

[0056] In the present invention, a high loss factor at 0 °C indicates good wet skid resistance of the elastomer.

[0057] According to the present invention, the loss factor of the crosslinked elastomer at 60 °C is less than or equal to 0.8.

[0058] In the present invention, a low loss factor at 60 °C indicates low rolling resistance of the elastomer. When at least one of the loss factors of the crosslinked elastomer at 0 °C and 60 °C meets the above range, it indicates that the crosslinked elastomer has excellent dynamic mechanical properties.

[0059] The third aspect of the present invention provides a method for preparing the above crosslinked elastomer, wherein the method includes: mixing and vulcanizing epoxidized nitrile rubber with the polyacid-modified filler to obtain the crosslinked elastomer;

[0060] The grafting rate of carboxyl groups in the polyacid-modified filler is 10 - 70%.

[0061] Further, the grafting rate of carboxyl groups in the polyacid-modified filler is 20 - 45%.

[0062] According to the present invention, the polyacid-modified filler is selected from at least one of polyacid-modified carbon black, polyacid-modified silica, polyacid-modified montmorillonite, polyacid-modified kaolin, polyacid-modified mica, and polyacid-modified talc powder.

[0063] Further, the polyacid-modified filler is a combination of polyacid-modified silica and at least one selected from polyacid-modified carbon black, polyacid-modified montmorillonite, polyacid-modified kaolin, polyacid-modified mica, and polyacid-modified talc powder.

[0064] According to the present invention, based on the total weight of the polyacid-modified filler, the dosage of the polyacid-modified silica is 5 - 100 wt%.

[0065] Further, based on the total weight of the polyacid-modified filler, the dosage of the polyacid-modified silica is 40 - 95 wt%.

[0066] In the present invention, there is no special limitation on the source of the polyacid-modified filler, and it can be prepared according to the existing preparation methods or obtained through commercial purchase.

[0067] The present invention does not particularly limit the preparation method of the polybasic acid-modified filler, and conventional modification methods in the art can be used. Preferably, to better modify the filler, the modification method includes: after grinding the filler into a uniform powder with a particle size of 10-50 nm, placing the filler and the polybasic acid modifier in a solvent, and stirring and reacting at 70-90 °C for 1-3 h to obtain the polybasic acid-modified filler.

[0068] According to a preferred embodiment of the present invention, the polybasic acid modifier is selected from at least one of dibasic acids, polybasic acids, and polybasic anhydrides.

[0069] Further, the polybasic acid modifier is a polybasic acid and / or a polybasic anhydride.

[0070] In the present invention, the dibasic acid is selected from at least one of malonic acid, phthalic acid, malic acid, and octadecane unsaturated fatty acid dimer.

[0071] In the present invention, the polybasic acid refers to a compound containing three or more carboxyl groups. Preferably, the polybasic acid is a tribasic acid and / or a tetrabasic acid. Preferably, the polybasic acid is citric acid.

[0072] Preferably, the mass ratio of the filler to the polybasic acid modifier is 1:2-50, preferably 1:2-40.

[0073] According to the present invention, the vulcanization temperature is 120-200 °C, the vulcanization pressure is 0.1-25 MPa, and the vulcanization time is 2 min-10 h.

[0074] Further, the vulcanization temperature is 150-190 °C, the vulcanization pressure is 10-20 MPa, and the vulcanization time is 10 min-120 min.

[0075] According to the present invention, the method includes: mixing and vulcanizing epoxidized nitrile rubber, the polybasic acid-modified filler, an ester exchange catalyst, an antioxidant, and a plasticizer to obtain the crosslinked elastomer.

[0076] In the present invention, the selection and dosage of the epoxidized nitrile rubber, the ester exchange catalyst, the antioxidant, and the plasticizer are the same as those of the epoxidized nitrile rubber, the ester exchange catalyst, the antioxidant, and the plasticizer in the first aspect, and will not be elaborated here.

[0077] In the present invention, after the crosslinked elastomer is physically damaged, the damaged crosslinked elastomer is hot-pressed to obtain a secondarily formed crosslinked elastomer. Preferably, the hot-pressing temperature is 120-200 °C, preferably 165-190 °C; the pressure is 0.1-25 MPa, preferably 10-20 MPa; the time is 2 min-10 h, preferably 5 min-4 h.

[0078] The present invention will be described in detail below by way of examples.

[0079] The tensile strength and elongation at break were measured by a tensile machine using the method of GB / T 528-1998.

[0080] The loss factor was measured by a DMA tester. The test frequency was 60 HZ, the temperature was from -80°C to 80°C, and the heating rate was 3°C / min.

[0081] Tensile strength of secondary hot pressing molding: The crosslinked elastomer was cut into pieces, and then the damaged crosslinked elastomer was re-hot pressed and molded on a flat vulcanizing machine under a pressure of 15 MPa at 190°C for 30 min to obtain a flat sample sheet with a thickness of 2 mm.

[0082] The stress relaxation time to 37% of the original stress was measured by a rubber processing analyzer. The fixed strain was 100%, and the test temperatures were 140°C and 160°C respectively.

[0083] The grafting rate of carboxyl groups in the polybasic acid-modified filler was measured by thermogravimetric method. The nitrogen atmosphere, the temperature was 40 - 800°C, and the heating rate was 10°C / min.

[0084] Epoxidized hydrogenated nitrile rubber: The epoxidized nitrile rubber obtained by copolymerizing acrylonitrile, butadiene and glycidyl methacrylate was hydrogenated to obtain epoxidized hydrogenated nitrile rubber. The epoxy degree of the epoxidized nitrile rubber was 55%, the content of acrylonitrile was 30 wt%, and the content of double bonds was 4.5 wt%.

[0085] Other raw materials used in the preparation examples, examples and comparative examples were all commercially available products.

[0086] Preparation Example 1

[0087] Polybasic acid-modified filler A: Weigh 100 g of silica, grind it in a ball mill for 60 min, take it out, place it in a solvent containing 100 ml of deionized water and 2500 ml of ethanol, ultrasonicate for 30 min, add 560 g of citric acid at 80°C, and react for 12 hours. The product was centrifuged with absolute ethanol. Dried for later use to obtain polybasic acid-modified silica. The grafting rate of carboxyl groups in the prepared polybasic acid-modified silica was 35%.

[0088] Preparation Example 2

[0089] Prepare polybasic acid-modified filler B according to the method of Preparation Example 1. The difference is that the silica is replaced with montmorillonite to obtain polybasic acid-modified montmorillonite. The grafting rate of carboxyl groups in the polybasic acid-modified montmorillonite is 31%.

[0090] Preparation Example 3

[0091] The polyacid-modified filler C was prepared according to the method of Preparation Example 1, except that the silica was replaced with carbon black to obtain a polyacid-modified carbon black, and the grafting rate of carboxyl groups in the polyacid-modified carbon black was 24%.

[0092] Preparation Example 4

[0093] The polyacid-modified filler D was prepared according to the method of Preparation Example 1, except that the silica was replaced with kaolin to obtain a polyacid-modified kaolin, and the grafting rate of carboxyl groups in the polyacid-modified kaolin was 26.8%.

[0094] Preparation Example 5

[0095] The polyacid-modified filler E was prepared according to the method of Preparation Example 1, except that the silica was replaced with mica to obtain a polyacid-modified mica, and the grafting rate of carboxyl groups in the polyacid-modified mica was 25.4%.

[0096] Preparation Example 6

[0097] The polyacid-modified filler F was prepared according to the method of Preparation Example 1, except that the silica was replaced with talcum powder to obtain a polyacid-modified talcum powder, and the grafting rate of carboxyl groups in the polyacid-modified talcum powder was 28.4%.

[0098] Preparation Example 7

[0099] The polyacid-modified filler G was prepared according to the method of Preparation Example 1, except that citric acid was replaced with 560 g of octadecane unsaturated fatty acid dimer to obtain a polyacid-modified silica, and the grafting rate of carboxyl groups in the polyacid-modified silica was 34.1%.

[0100] Preparation Example 8

[0101] The polyacid-modified filler H was prepared according to the method of Preparation Example 1, except that citric acid was replaced with 560 g of octadecane unsaturated fatty acid dimer and the silica was replaced with montmorillonite to obtain a polyacid-modified montmorillonite, and the grafting rate of carboxyl groups in the polyacid-modified montmorillonite was 32.4%.

[0102] Preparation Example 9

[0103] The polyacid-modified filler X was prepared according to the method of Preparation Example 1, except that 105 g of citric acid was used to obtain a polyacid-modified silica, and the grafting rate of carboxyl groups in the polyacid-modified silica was 6%.

[0104] Example 1

[0105] Mix 135 g of epoxidized hydrogenated nitrile rubber, 0.7 g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 2.7 g of antioxidant 4020, 4.1 g of naphthenic oil, 33.75 g of citric acid modified silica, and 33.75 g of citric acid modified carbon black at 50 °C, and then take out the sheet.

[0106] Under the conditions of 15 MPa pressure and 175 °C, press and mold to make a cross-linked elastomer sample sheet with a thickness of 2 mm. The vulcanization time is 30 min. The properties of the cross-linked elastomer are shown in Table 2.

[0107] Example 2 - 10

[0108] Prepare the cross-linked elastomer according to the method of Example 1. The difference is that the selection and dosage of raw materials are shown in Table 1, and the properties of the cross-linked elastomer are shown in Table 2.

[0109] Comparative Example 1 - 4

[0110] Prepare the cross-linked elastomer according to the method of Example 1. The difference is that the selection and dosage of raw materials are shown in Table 1, and the properties of the cross-linked elastomer are shown in Table 2.

[0111] Comparative Example 5

[0112] Mix 135 g of epoxidized hydrogenated nitrile rubber, 0.7 g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 2.7 g of antioxidant 4020, 4.1 g of naphthenic oil, 21.94 g of silica, 21.94 g of carbon black, and 23.625 g of citric acid at 50 °C, and then take out the sheet.

[0113] Under the conditions of 15 MPa pressure and 175 °C, press and mold to make a cross-linked elastomer sample sheet with a thickness of 2 mm. The vulcanization time is 30 min. The properties of the cross-linked elastomer are shown in Table 2.

[0114] Table 1

[0115]

[0116]

[0117] Continued Table 1

[0118]

[0119] Continued Table 1

[0120]

[0121]

[0122] Table 2

[0123]

[0124] It can be seen from the results that, compared with the comparative example, the crosslinked elastomer of the present invention has the characteristics of high tensile strength, high tensile strength in secondary hot pressing molding, and fast stress relaxation at 140 °C and 160 °C. At the same time, the crosslinked elastomer has a high loss factor at 0 °C and a low loss factor at 60 °C, indicating that the crosslinked elastomer of the present invention has excellent anti-slip and low rolling resistance performance.

[0125] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A composition of a crosslinked elastomer, characterized in that, The composition comprises epoxidized nitrile rubber, polyacid-modified filler and transesterification catalyst; Based on 100 parts by weight of the epoxidized nitrile rubber, the content of the polyacid-modified filler is 8 - 100 parts by weight, and the transesterification catalyst is 0.5 - 10 parts by weight; The grafting rate of carboxyl groups in the polyacid-modified filler is 10 - 70%.

2. The composition according to claim 1, wherein, Based on 100 parts by weight of the epoxidized nitrile rubber, the content of the polyacid-modified filler is 30 - 80 parts by weight, and the transesterification catalyst is 0.5 - 3 parts by weight; The grafting rate of carboxyl groups in the polyacid-modified filler is 20 - 45%.

3. The composition according to claim 1 or 2, wherein The epoxy degree of the epoxidized nitrile rubber is 10 - 80%, preferably 25 - 60%; Preferably, the acrylonitrile content in the epoxidized nitrile rubber is 10 - 50 wt%, preferably 20 - 35 wt%; Preferably, the epoxidized nitrile rubber is epoxidized hydrogenated nitrile rubber; Preferably, the double bond content in the epoxidized hydrogenated nitrile rubber is 0.1 wt% - 20 wt%, preferably 0.5 wt% - 5 wt%.

4. The composition according to any one of claims 1-3, wherein The polyacid-modified filler is selected from at least one of polyacid-modified carbon black, polyacid-modified silica, polyacid-modified montmorillonite, polyacid-modified kaolin, polyacid-modified mica and polyacid-modified talc powder; preferably a combination of polyacid-modified silica and at least one selected from polyacid-modified carbon black, polyacid-modified montmorillonite, polyacid-modified kaolin, polyacid-modified mica and polyacid-modified talc powder; Preferably, based on the total weight of the polyacid-modified filler, the content of the polyacid-modified silica is 5 - 100 wt%, preferably 40 - 95 wt%.

5. According to the composition described in any one of claims 1 - 4, based on 100 parts by weight of the epoxidized nitrile rubber, the antioxidant is 0.06 - 4 parts by weight, preferably 1 - 3.5 parts by weight; Preferably, the composition further comprises a plasticizer; Preferably, based on 100 parts by weight of the epoxidized nitrile rubber, the plasticizer is 0.1 - 20 parts by weight, preferably 3 - 8 parts by weight.

6. A crosslinked elastomer, characterized in that, The crosslinked elastomer is prepared by mixing and vulcanizing the composition of the crosslinked elastomer described in any one of claims 1 - 5.

7. The crosslinked elastomer according to claim 6, wherein, The tensile strength of the crosslinked elastomer is greater than or equal to 20 MPa, preferably greater than or equal to 25 MPa; Preferably, the elongation at break of the crosslinked elastomer is 400 - 800%, preferably 400 - 700%; Preferably, at 140 °C, the time for the crosslinked elastomer to stress-relax to 37% of the original stress is less than or equal to 70 min, preferably less than or equal to 60 min; Preferably, at 160 °C, the time for the crosslinked elastomer to stress-relax to 37% of the original stress is less than or equal to 30 min, preferably less than or equal to 20 min. Preferably, the loss factor of the crosslinked elastomer at 0 °C is greater than or equal to 1.2; Preferably, the loss factor of the crosslinked elastomer at 60 °C is less than or equal to 0.

8.

8. A method for preparing the crosslinked elastomer according to claim 6 or 7, characterized in that, The method includes: mixing and vulcanizing the epoxidized nitrile rubber with the polyacid-modified filler to obtain the crosslinked elastomer; The grafting rate of carboxyl groups in the polybasic acid-modified filler is 10-70%.

9. The method according to claim 8, wherein, The grafting rate of carboxyl groups in the polybasic acid-modified filler is 20-45%; Preferably, the polybasic acid-modified filler is selected from at least one of polybasic acid-modified carbon black, polybasic acid-modified silica, polybasic acid-modified montmorillonite, polybasic acid-modified kaolin, polybasic acid-modified mica, and polybasic acid-modified talc powder; preferably a combination of polybasic acid-modified silica and at least one selected from polybasic acid-modified carbon black, polybasic acid-modified montmorillonite, polybasic acid-modified kaolin, polybasic acid-modified mica, and polybasic acid-modified talc powder; Preferably, based on the total weight of the polybasic acid-modified filler, the amount of the polybasic acid-modified silica is 5-100 wt%, preferably 40-95 wt%; Preferably, the temperature of vulcanization is 120-200 °C, preferably 150-190 °C; Preferably, the pressure of vulcanization is 0.1-25 MPa, preferably 10-20 MPa; Preferably, the time of vulcanization is 2 min-10 h, preferably 10-120 min.

10. The method according to claim 8 or 9, wherein The method includes: mixing and vulcanizing epoxidized nitrile rubber, the polybasic acid-modified filler, a transesterification catalyst, an antioxidant, and a plasticizer to obtain the crosslinked elastomer.

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