Copolymer, preparation method thereof, cross-linked elastomer material and preparation method and application of cross-linked elastomer material

Abstract

The invention relates to the technical field of copolymerization materials and preparation, and discloses a copolymer and a preparation method thereof as well as a cross-linked elastomer material and a preparation method and application thereof, the copolymer comprises three structural units A, B and C. A is from a structural unit of an ethylene monomer, B is from a structural unit of an alpha-olefin monomer, and C is from a structural unit of an acrylate monomer. And a crosslinking structure from a crosslinking monomer; the copolymer has the following structure: A and C form a-A-C-A-C-alternating structure, and a part of position of A is replaced by B; wherein on the basis of the total molar content of the copolymer, the content of the structural unit A is 20-60 mol%, the content of the structural unit B is 5-30 mol%, and the content of the structural unit C is 30-65 mol%. The cross-linked elastomer material prepared by cross-linking the copolymer provided by the invention has the characteristics of low temperature resistance, oil resistance and high mechanical strength.

Description

Technical Field

[0001] This invention relates to the field of copolymer materials and their preparation technology, specifically to a copolymer and its preparation method, and a crosslinked elastomer material and its preparation method and application. Background Technology

[0002] Copolymerizing nonpolar ethylene monomers with polar acrylate monomers can yield amorphous polymers with unique comprehensive properties unmatched by homopolymerization of either nonpolar or polar monomers, such as oil resistance, heat resistance, and adhesion. Through crosslinking reactions, the copolymers can be prepared into rubber products, used in the automotive, industrial machinery, and general equipment industries as oil-resistant seals, damping components, etc. In practical applications, in addition to good oil resistance, rubber products also need to withstand low-temperature conditions and high loads or stresses, exhibiting both low-temperature resistance and high load-bearing capacity. Therefore, to meet the demands of different working conditions and to give these rubber elastomer materials prepared by copolymerizing nonpolar and polar monomers stronger environmental adaptability and application potential, the rubber elastomers need to possess excellent properties in low-temperature resistance, oil resistance, and mechanical strength.

[0003] CN116997580A discloses an ethylene-(meth)acrylate elastomer and its manufacturing method. This method copolymerizes 40-79.9% ethylene with 20-50% alkyl (meth)acrylates having 1-8 carbon atoms and / or alkoxy (meth)acrylates having 2-8 carbon atoms, 0.05-20% unsaturated dicarboxylic acids, and 0.05-20% unsaturated dicarboxylic anhydrides. The resulting crosslinked rubber material has a glass transition temperature of -30℃ and good low-temperature resistance; however, it has poor oil resistance, with a volume increase of 36.8-125.2% after immersion in standard oil for 70 hours. Furthermore, the manufacturing conditions for this elastomer are demanding, requiring high temperature and high pressure conditions of 150-170℃ and 100-250 MPa.

[0004] CN101878232A discloses a catalyst composition for preparing 1-olefin and acrylate copolymers, as well as a method for preparing 1-olefin and acrylate copolymers. The 1-olefin-acrylate copolymers obtained by this method have a high glass transition temperature, but as rubber elastomers, they exhibit insufficient low-temperature resistance.

[0005] Therefore, it is necessary to design new rubber materials that combine low-temperature resistance, oil resistance, and high strength, and to establish preparation technologies to meet the application requirements of oil-resistant sealing, damping, and other materials under different working conditions. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem that existing elastomer materials cannot simultaneously achieve low-temperature resistance, oil resistance, and high strength, and to provide a copolymer and its preparation method, as well as a crosslinked elastomer material, its preparation method, and its applications. The crosslinked elastomer material prepared from the copolymer provided by this invention exhibits low-temperature resistance, oil resistance, and high mechanical strength.

[0007] To achieve the above objectives, the first aspect of the present invention provides a copolymer comprising three structural units: A, B, and C, wherein A is a structural unit derived from an ethylene monomer, B is a structural unit derived from an α-olefin monomer, C is a structural unit derived from an acrylate monomer, and a crosslinking structure derived from a crosslinking monomer. The copolymer has the following structure: A and C form an alternating -ACAC- structure, and some positions of A are replaced by B; Based on the total molar content of the copolymer, the content of structural unit A is 20-60 mol%, the content of structural unit B is 5-30 mol%, and the content of structural unit C is 30-65 mol.

[0008] A second aspect of the present invention provides a method for preparing the above-mentioned copolymer, comprising: mixing α-olefin, acrylate, Lewis acid, initiator and crosslinking monomer in an organic solvent under polymerization reaction conditions, introducing ethylene and then polymerizing to obtain a polymer solution; and precipitating and drying the polymer solution to obtain the copolymer. The amount of ethylene charged results in a polymerization pressure of 0.5-20 MPa, and the amount of α-olefin used is 5-100 mol, based on the amount of acrylate monomer.

[0009] A third aspect of the present invention provides a crosslinked elastomer material, wherein the crosslinked elastomer material is obtained by vulcanization of the above-mentioned copolymer.

[0010] A fourth aspect of the present invention provides a method for preparing the above-mentioned crosslinked elastomer material, wherein the method includes: mixing the copolymer, a vulcanizing agent and a filler to obtain a blend, and vulcanizing the blend to obtain a crosslinked elastomer material.

[0011] The fifth aspect of the present invention provides an application of the above-mentioned cross-linked elastomer material as a sealing material or a damping material.

[0012] Through the above technical solutions, the copolymers and their preparation methods, as well as the crosslinked elastomer materials and their preparation methods and applications provided by the present invention, have the following beneficial effects.

[0013] The copolymer in this invention is an ethylene-α-olefin-acrylate copolymer, wherein structural unit A from ethylene and structural unit C from acrylate form an alternating -ACAC- structure, and some positions of A are replaced by structural unit B from α-olefin. Furthermore, when the content of each structural unit in the ternary copolymer meets a specific range, the crosslinked elastomer material produced by crosslinking this copolymer exhibits excellent performance in terms of low-temperature resistance, oil resistance, and mechanical strength. The crosslinked elastomer material of this invention can be used as a sealing material and a damping material, meeting the requirements of low-temperature resistance, oil resistance, and high mechanical strength under operating conditions. Attached Figure Description

[0014] Figure 1 This is the 1H NMR spectrum of Preparation Example 1.

[0015] Figure 2 This is the carbon NMR spectrum of Preparation Example 1.

[0016] Figure 3 These are the molecular weight distribution curves for Preparation Example 3, Preparation Example 4, and Preparation Example 6.

[0017] Figure 4 These are the DSC curves for Examples 1, 3, and 7. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The first aspect of the present invention provides a copolymer, wherein the copolymer comprises three structural units: A, B, and C, wherein A is a structural unit derived from an ethylene monomer, B is a structural unit derived from an α-olefin monomer, C is a structural unit derived from an acrylate monomer, and a crosslinking structure derived from a crosslinking monomer; The copolymer has the following structure: A and C form an alternating -ACAC- structure, and some positions of A are replaced by B; Based on the total molar content of the copolymer, the content of structural unit A is 20-60 mol%, the content of structural unit B is 5-30 mol%, and the content of structural unit C is 30-65 mol.

[0020] In this invention, the copolymer is an ethylene-α-olefin-acrylate copolymer, wherein structural unit A from ethylene and structural unit C from acrylate form an alternating -ACAC- structure, and some positions of A are replaced by structural unit B from α-olefin. Furthermore, when the content of each structural unit in the ternary copolymer meets a specific range, the crosslinked elastomer material produced by crosslinking this copolymer exhibits excellent performance in terms of low-temperature resistance, oil resistance, and mechanical strength. The crosslinked elastomer material of this invention can be used as a sealing material and a damping material, meeting the requirements of low-temperature resistance, oil resistance, and high mechanical strength under operating conditions.

[0021] In this invention, A and C form an alternating -ACAC- structure, and the partial replacement of A by B means that structural unit A or structural unit B and structural unit C form an alternating sequence structure. For example, -ACAC-, -BCBC-, and -ACBCAC- all belong to the alternating sequence structures described in this invention. The copolymers of this invention also contain non-alternating structures such as -AA-, -BB-, -CC-, and -AB-, but the content of non-alternating structures in the copolymer is lower than the content of alternating sequence structures; therefore, copolymers containing a small amount of non-alternating structures are copolymers with alternating sequence structures.

[0022] In this invention, the total molar amount of structural unit A, structural unit B and structural unit C is 100 mol.

[0023] Furthermore, based on the total molar content of the copolymer, the content of structural unit A is 30-45 mol%, the content of structural unit B is 5-20 mol%, and the content of structural unit C is 40-60 mol.

[0024] According to the present invention, the α-olefin monomer is a C4-C42 α-olefin.

[0025] In this invention, when the copolymer contains the above-mentioned α-olefin structural units, the resulting crosslinked elastomer material has the characteristics of low glass transition temperature and high mechanical strength while maintaining high oil resistance.

[0026] Furthermore, the α-olefin monomer is a C4-C20 α-olefin.

[0027] According to the present invention, the structure of the acrylate monomer is as shown in formula (1); Equation (1), Wherein, R1 is hydrogen or methyl, and R2 is a straight-chain alkyl group of C1-C8, a branched alkyl group of C3-C8, or the structure shown in formula (2); Equation (2), Wherein, R3 is a C2-C3 alkylene group, R4 is hydrogen or methyl, and n is an integer from 1 to 5.

[0028] In this invention, when the copolymer contains the structural units derived from the acrylate monomers described above, the copolymer exhibits high polarity, and the resulting crosslinked elastomer material exhibits high oil resistance.

[0029] Further, in formula (1), R1 is hydrogen or methyl, R2 is a straight-chain alkyl group of C1-C5, a branched alkyl group of C3-C5, or the structure shown in formula (2); wherein, R3 is ethylene, R4 is hydrogen or methyl, and n is an integer from 1 to 3.

[0030] Furthermore, the acrylate monomer is selected from at least one of methyl acrylate, ethyl acrylate, and 2-(2-methoxyethoxy)ethyl acrylate.

[0031] According to the present invention, the content of the cross-linked structure accounts for 0.1 mol%-10 mol% of the total content of the three structural units A, B and C.

[0032] In this invention, when the content of the cross-linked structure meets the above-mentioned range, the cross-linked elastomer material obtained by the copolymer has excellent low-temperature resistance, oil resistance, and high mechanical strength.

[0033] Furthermore, the content of the cross-linked structure accounts for 0.5 mol%-5 mol% of the total content of the three structural units A, B, and C.

[0034] According to the present invention, the crosslinking monomer is selected from at least one of nonpolar dienes, polar haloacrylates, polar halovinyl acetates, polar halovinyl ethers, polar epoxy acrylates, and polar epoxy allyl ethers.

[0035] Further, the crosslinking monomer is at least one selected from ethylidene norbornene, dicyclopentadiene, 1,7-octadiene, methyl chloroacrylate, vinyl chloroacetate, 2-chloroethyl vinyl ether, glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether.

[0036] According to the present invention, the number average molecular weight of the copolymer is 20,000-400,000 g / mol.

[0037] In this invention, when the number-average molecular weight of the copolymer meets the above-mentioned range, it indicates that the copolymer has excellent processing performance, and the elastomer made from the copolymer has excellent mechanical properties (tensile strength).

[0038] Furthermore, the number-average molecular weight of the copolymer is 40,000-200,000 g / mol.

[0039] According to the present invention, the molecular weight distribution of the copolymer is 1-10.

[0040] Furthermore, the copolymer has a molecular weight distribution of 1-5.

[0041] A second aspect of the present invention provides a method for preparing a copolymer, wherein the method comprises: mixing an α-olefin monomer, an acrylate monomer, a Lewis acid, an initiator, and a crosslinking monomer in an organic solvent under polymerization reaction conditions, introducing an ethylene monomer, and then polymerizing to obtain a polymer solution; the polymer solution is precipitated and dried to obtain a copolymer; The amount of ethylene charged results in a polymerization pressure of 0.5-20 MPa, and the amount of α-olefin monomer used is 5-100 mol, based on the amount of acrylate monomer used.

[0042] Furthermore, the amount of ethylene charged results in a polymerization pressure of 1-10 MPa, and the amount of α-olefin monomer used is 5-50 mol based on the amount of acrylate monomer used.

[0043] According to a preferred embodiment of the present invention, the amount of ethylene charged is such that the polymerization pressure is 1-6 MPa, and the amount of α-olefin monomer is 10-30 mol based on the amount of acrylate monomer.

[0044] According to the present invention, the amount of Lewis acid is 0.001 mol%-200 mol, based on the amount of acrylate monomer.

[0045] In this invention, when the amount of Lewis acid meets the above-mentioned range, it is beneficial to obtain copolymers with alternating sequence structures.

[0046] Furthermore, based on the amount of acrylate monomer used, the amount of Lewis acid used is 0.1 mol%-150 mol.

[0047] Furthermore, based on the amount of acrylate monomer used, the amount of Lewis acid used is 1-120 mol.

[0048] According to the present invention, the Lewis acid is selected from metal oxides and / or halides.

[0049] In this invention, the Lewis acids of the above types are used to control the polymerization rate of acrylate with ethylene and α-olefins. The resulting copolymers are used to prepare cross-linked elastomer materials, which have excellent oil resistance, low-temperature resistance and high mechanical strength.

[0050] Further, the Lewis acid is selected from at least one of alumina, aluminum trichloride, ferric chloride, tin tetrachloride, titanium tetrachloride, boron trifluoride, cerium trifluoromethanesulfonate, copper trifluoromethanesulfonate, hafnium trifluoromethanesulfonate, and scandium trifluoromethanesulfonate.

[0051] According to the present invention, the amount of the initiator is 0.001 mol%-5 mol, based on the amount of acrylate monomer.

[0052] In this invention, when the amount of initiator meets the above range, the polymerization reaction rate is high and a copolymer with a specific molecular weight can be obtained. The elastomer made from this copolymer has excellent mechanical properties (tensile strength).

[0053] Furthermore, based on the amount of acrylate monomer used, the amount of the initiator is 0.01 mol% to 1 mol.

[0054] According to the present invention, the initiator is selected from at least one of azo initiators, peroxide initiators, and redox initiators.

[0055] In this invention, there is no particular limitation on the specific type of initiator; conventional initiators in the art can be used. Preferably, the azo initiator is azobisisobutyronitrile and / or azobisisoheptanenitrile. Preferably, the peroxide initiator is selected from at least one of benzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, and dicumene peroxide. Preferably, in the redox initiator, the oxidant is selected from at least one of hydroperoxide, dialkyl peroxide, and diacyl peroxide, and the reducing agent is selected from at least one of tertiary amine, thiol, and oxalic acid.

[0056] According to the present invention, the organic solvent is selected from at least one of chloroform, dichloromethane, chlorobenzene, acetone, toluene, xylene, ethyl acetate and tetrahydrofuran.

[0057] In this invention, the molar ratio of the acrylate to the volume of the organic solvent is 0.1-5 mol / L.

[0058] Furthermore, the molar ratio of the acrylate to the volume of the organic solvent is 0.3-3 mol / L.

[0059] According to the present invention, the polymerization temperature is 20-100°C, and the polymerization time is 2-24 hours.

[0060] In this invention, when the polymerization conditions meet the above requirements, the polymer molecular weight and monomer conversion rate can be controlled, thereby improving the mechanical strength of the crosslinked elastomer material and reducing production costs.

[0061] Furthermore, the polymerization temperature is 30-80℃, and the polymerization time is 4-12h.

[0062] According to the present invention, the amount of the crosslinking monomer is 0.01 mol%-20 mol, based on the amount of acrylate monomer.

[0063] In this invention, when the amount of crosslinking monomers meets the above range, the resulting copolymer has a specific crosslinking structure, and the crosslinked elastomer material made from this copolymer has excellent low-temperature resistance, oil resistance, and high mechanical strength.

[0064] Furthermore, based on the amount of acrylate monomer used, the amount of crosslinking monomer used is 0.05 mol%-10 mol.

[0065] According to the present invention, the crosslinking monomer is selected from at least one of nonpolar dienes, polar haloacrylates, polar halovinyl acetates, polar halovinyl ethers, polar epoxy acrylates, and polar epoxy allyl ethers.

[0066] Further, the crosslinking monomer is at least one selected from ethylidene norbornene, dicyclopentadiene, 1,7-octadiene, methyl chloroacrylate, vinyl chloroacetate, 2-chloroethyl vinyl ether, glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether.

[0067] A third aspect of the present invention provides a crosslinked elastomer material, wherein the crosslinked elastomer material is obtained by vulcanization of the above-mentioned copolymer.

[0068] In this invention, the cross-linked elastomer material prepared by cross-linking with a specific copolymer exhibits excellent performance in terms of low-temperature resistance, oil resistance, and mechanical strength. The cross-linked elastomer material of this invention can be used as a sealing material and a damping material, meeting the requirements of operating conditions that simultaneously demand low-temperature resistance, oil resistance, and high mechanical strength.

[0069] According to the present invention, the glass transition temperature of the crosslinked elastomer material is -40°C to 5°C.

[0070] Furthermore, the glass transition temperature of the crosslinked elastomer material is -35°C to 0°C.

[0071] According to the present invention, after the crosslinked elastomer material is aged in IRM901 standard oil at 100°C for 70 hours, the volume change percentage ΔV is less than or equal to 15%.

[0072] Furthermore, after aging the crosslinked elastomer material in IRM901 standard oil at 100°C for 70 hours, the volume change percentage ΔV is less than or equal to 10%.

[0073] According to the present invention, the tensile strength of the crosslinked elastomer material is greater than or equal to 12 MPa.

[0074] Furthermore, the tensile strength of the cross-linked elastomer material is greater than or equal to 15 MPa.

[0075] A fourth aspect of the present invention provides a method for preparing the above-mentioned crosslinked elastomer material, wherein the method includes: mixing the copolymer, a vulcanizing agent and a filler to obtain a blend, and vulcanizing the blend to obtain a crosslinked elastomer material.

[0076] According to the present invention, in the blend, the copolymer is 100 parts by weight, the filler is 10-100 parts by weight, and the vulcanizing agent is 0.1-10 parts by weight.

[0077] Furthermore, in the blend, the copolymer is 100 parts by weight, the filler is 30-100 parts by weight, and the vulcanizing agent is 1-5 parts by weight.

[0078] In this invention, there is no particular limitation on the type of filler, and conventional fillers in the art can be used. Preferably, the filler is silicon dioxide.

[0079] In this invention, there is no particular limitation on the type of vulcanizing agent, and conventional vulcanizing agents in the art can be used. Preferably, the vulcanizing agent is selected from at least one of sulfur, peroxide, diamine, polyamine, binary epoxy compound, and multi-cyclic epoxy compound.

[0080] According to the present invention, there are no particular limitations on the vulcanization temperature and vulcanization time. Those skilled in the art can adjust the vulcanization temperature and time according to the crosslinking monomer and the selected vulcanizing agent.

[0081] The fifth aspect of the present invention provides an application of the above-mentioned cross-linked elastomer material as a sealing material or a damping material.

[0082] The present invention will be described in detail below through embodiments.

[0083] The number-average molecular weight and molecular weight distribution of the copolymers were determined by gel permeation chromatography.

[0084] The content and structural composition of each structural unit in the copolymer were determined by nuclear magnetic resonance spectroscopy.

[0085] Low-temperature performance: The glass transition temperature (Tg) of the copolymer was tested using differential scanning calorimetry. g (Evaluate)

[0086] Oil resistance: Tested according to GB / T 1690-2010, the percentage change in volume ΔV of the elastomer after aging in IRM901 standard oil at 100℃ for 70h was evaluated (calculated according to formula (2) in 7.3 Volume Change in GB / T 1690-2010).

[0087] Tensile strength: According to GB / T 528-2009, the tensile strength of the dumbbell-shaped elastomer specimens was tested using a universal tensile testing machine at a tensile rate of 500 mm / min.

[0088] The raw materials used in the following examples and comparative examples are all commercially available products.

[0089] Preparation Example 1 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, methyl acrylate, 1-octadecene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene. The ethylene pressure was maintained at 4 MPa, and the reaction was carried out at 40°C for 8 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0090] Based on the amount of acrylate monomer used, the α-olefin is 16.7 mol%, the Lewis acid is 10 mol%, the initiator is 0.5 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of acrylate to organic solvent volume is 0.6 mol / L.

[0091] Preparation Example 2 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, ethyl acrylate, 1-octene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene at a pressure of 2 MPa. The reaction was carried out at 40°C for 7 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0092] Based on the amount of acrylate monomer used, the α-olefin is 26.7 mol%, the Lewis acid is 20 mol%, the initiator is 0.5 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of acrylate to organic solvent volume is 0.6 mol / L.

[0093] Preparation Example 3 Azobisisobutyronitrile (AIBN), scandium trifluoromethanesulfonate (STMS), ethyl acrylate (EY), 1-octadecene, vinyl chloroacetate (VCA), and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and then filled with ethylene at a pressure of 6 MPa. The reaction was carried out at 60°C for 8 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate the polymer, followed by drying and purification to obtain the copolymer.

[0094] Based on the amount of acrylate monomer used, the α-olefin is 10 mol%, the Lewis acid is 15 mol%, the initiator is 0.33 mol%, and the crosslinking monomer is 7 mol%. The molar ratio of acrylate to organic solvent volume is 0.6 mol / L.

[0095] Preparation Example 4 Azobisisobutyronitrile (AIBN), aluminum trichloride, ethyl acrylate, 1-octadecene, vinyl chloride chloroacetate, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene, maintaining the ethylene pressure at 6 MPa. The reaction was carried out at 60°C for 8 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0096] Based on the amount of acrylate monomer used, the α-olefin is 33.3 mol%, the Lewis acid is 100 mol%, the initiator is 0.33 mol%, and the crosslinking monomer is 7 mol%. The molar ratio of the acrylate to the volume of the organic solvent is 0.6 mol / L.

[0097] Preparation Example 5 Azobisisobutyronitrile (AIBN), aluminum trichloride (ACH), methyl acrylate (Methyl acrylate), 1-hexene, vinyl chloroacetate (CHC), and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and then filled with ethylene at a pressure of 6 MPa. The reaction was carried out at 60°C for 8 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate the polymer, followed by drying and purification to obtain the copolymer.

[0098] Based on the amount of acrylate monomer used, the α-olefin is 10 mol%, the Lewis acid is 80 mol%, the initiator is 0.33 mol%, and the crosslinking monomer is 7 mol%. The molar ratio of acrylate to organic solvent volume is 0.6 mol / L.

[0099] Preparation Example 6 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, ethyl acrylate, 1-octadecene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene at a pressure of 2 MPa. The reaction was carried out at 40°C for 8 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0100] Based on the amount of acrylate monomer used, the α-olefin is 10 mol%, the Lewis acid is 10 mol%, the initiator is 0.27 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of acrylate to organic solvent volume is 0.6 mol / L.

[0101] Preparation Example 7 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, ethyl acrylate, 1-octene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene at a pressure of 1 MPa. The reaction was carried out at 50°C for 5 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0102] Based on the amount of acrylate monomer used, the α-olefin is 37.5 mol%, the Lewis acid is 10 mol%, the initiator is 0.2 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of the acrylate to the volume of the organic solvent is 0.5 mol / L.

[0103] Preparation Example 8 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, methyl acrylate, 2-(2-methoxyethoxy)ethyl acrylate (acrylate monomer), 1-octadecene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene at a pressure of 6 MPa. The reaction was carried out at 40°C for 6 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water for precipitation, followed by drying and purification to obtain the copolymer.

[0104] Based on the amount of acrylate monomer used, the α-olefin is 7.5 mol%, the Lewis acid is 10 mol%, the initiator is 0.25 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of acrylate to organic solvent volume is 0.5 mol / L.

[0105] Preparation Example 9 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, ethyl acrylate, 1-octadecene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene at a pressure of 2 MPa. The reaction was carried out at 40°C for 8 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0106] Based on the amount of acrylate monomer used, the α-olefin is 50 mol%, the Lewis acid is 10 mol%, the initiator is 0.27 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of acrylate to organic solvent volume is 0.6 mol / L.

[0107] Comparative Preparation Example 1 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, methyl acrylate, vinyl chloroacetate, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene, maintaining an ethylene pressure of 4 MPa. The reaction was carried out at 40°C for 6 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0108] Specifically, based on the amount of acrylate monomer used, the amount of Lewis acid is 10 mol%, the amount of initiator is 0.33 mol%, and the amount of crosslinking monomer is 7 mol%. The molar amount of acrylate to the volume of organic solvent is 0.6 mol / L.

[0109] Comparative Preparation Example 2 Azobisisobutyronitrile, scandium trifluoromethanesulfonate, methyl acrylate, 1-decene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was purged with high-pressure nitrogen, and then filled with nitrogen at a pressure maintained at 4 MPa. The reaction was carried out at 40°C for 6 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate the polymer, which was then dried and purified to obtain the copolymer.

[0110] Based on the amount of acrylate monomer used, the α-olefin is 200 mol%, the Lewis acid is 10 mol%, the initiator is 0.33 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of acrylate to organic solvent volume is 0.375 mol / L.

[0111] Comparative preparation example 3 Azobisisobutyronitrile (AIBN), scandium trifluoromethanesulfonate (STMS), methyl acrylate (Methyl acrylate), 1-octadecene, vinyl chloroacetate (VCA), and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and then filled with ethylene at a pressure of 5 MPa. The reaction was carried out at 60°C for 8 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate the polymer, which was then dried and purified to obtain the copolymer.

[0112] Based on the amount of acrylate monomer used, the α-olefin is 5 mol%, the Lewis acid is 8 mol%, the initiator is 0.26 mol%, and the crosslinking monomer is 7 mol%. The molar ratio of acrylate to organic solvent volume is 0.6 mol / L.

[0113] Comparative preparation example 4 Azobisisobutyronitrile, aluminum trichloride, methyl acrylate, 1-decene, 1,7-octadiene, and chloroform were added to a high-pressure reactor. The reactor was vented using high-pressure ethylene, and finally filled with ethylene at a pressure maintained at 0.5 MPa. The reaction was carried out at 40°C for 6 hours to obtain a polymer solution. The polymer solution was then added to a mixture of methanol and deionized water to precipitate, dried, and purified to obtain the copolymer.

[0114] Based on the amount of acrylate monomer used, the α-olefin is 150 mol%, the Lewis acid is 100 mol%, the initiator is 0.26 mol%, and the crosslinking monomer is 1.5 mol%. The molar ratio of acrylate to organic solvent volume is 0.375 mol / L.

[0115] The structures and properties of the polymers obtained from the preparation examples and comparative preparation examples are shown in Table 1.

[0116] Table 1

[0117] Examples 1-9 The copolymers synthesized in Examples 1-9 were premixed with a vulcanizing agent and filler (100 parts copolymer, 60 parts SiO2 filler, and 2 parts benzoyl peroxide vulcanizing agent) in a Banbury mixer, followed by mixing in a two-roll mill to obtain a homogeneous blend. Finally, the blend was vulcanized in a flat vulcanizing mold to obtain a crosslinked elastomer material. The vulcanization conditions included: vulcanization at 120°C for 10 min, followed by vulcanization at 140°C for 20 min, and then vulcanization at 170°C for 10 min, with a vulcanization pressure of 10 MPa. The properties of the obtained crosslinked elastomer material are shown in Table 2.

[0118] Comparative Examples 1-4 Following the method of Example 1, the copolymers synthesized in Comparative Preparation Examples 1-4 were used to prepare crosslinked elastomers. The properties of the obtained crosslinked elastomer materials are shown in Table 2.

[0119] Table 2

[0120] By comparing the examples and comparative examples (as shown in Table 2), it can be found that the elastomer prepared based on the copolymer composed of ethylene, α-olefin and acrylate can obtain a lower glass transition temperature, extremely low standard oil swelling degree and high tensile strength, showing good comprehensive performance with low temperature resistance, oil resistance and high strength. However, the binary copolymer composed of ethylene or α-olefin and acrylate only shows excellent performance in oil resistance and tensile strength (Comparative Example 1) or low temperature resistance (Comparative Example 2). Its performance in other aspects is inferior to the copolymer provided by the present invention. When the content of α-olefin structural units is too low or too high, it will lead to a decrease in low temperature resistance and strength (Comparative Example 3) or a decrease in oil resistance (Comparative Example 4).

[0121] Figure 1 The image shows the 1H NMR spectrum of the copolymer from Preparation Example 1, from which the polymer structure obtained using Preparation Example 1 can be seen, indicating that ethylene, α-olefin, acrylate, and crosslinking monomers were all introduced into the copolymer.

[0122] Figure 2 The NMR 1C spectrum of the copolymer prepared in Example 1 shows the polymer structure and sequence structure obtained in Example 1. No obvious homopolymer sequence was found in the spectrum, and the main sequence was alternating, indicating that an ethylene-α-olefin-acrylate copolymer with alternating structure was prepared.

[0123] Figure 3 The figures show the molecular weight distribution curves of the copolymers prepared in Example 3, Example 4, and Example 6. It can be seen that the number average molecular weight of the polymers obtained by the above preparation methods is not less than 20,000 g / mol.

[0124] Figure 4 The DSC curves of the copolymers of Preparation Example 1, Preparation Example 3, and Preparation Example 7 show that the DSC curves contain only one glass transition and no glass transition of the homopolymer is observed, indicating that the polymer used in the elastomer material is a copolymer structure; moreover, the glass transition temperature is much lower than 0°C, indicating that it has high low-temperature resistance.

[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 inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A copolymer, characterized in that, The copolymer comprises three structural units: A, B, and C, wherein A is a structural unit derived from ethylene monomer, B is a structural unit derived from α-olefin monomer, C is a structural unit derived from acrylate monomer, and a crosslinking structure derived from crosslinking monomer. The copolymer has the following structure: A and C form an alternating -ACAC- structure, and some positions of A are replaced by B; Based on the total molar content of the copolymer, the content of structural unit A is 20-60 mol%, the content of structural unit B is 5-30 mol%, and the content of structural unit C is 30-65 mol.

2. The copolymer according to claim 1, wherein, Based on the total molar content of the copolymer, the content of structural unit A is 30-45 mol%, the content of structural unit B is 5-20 mol%, and the content of structural unit C is 40-60 mol%. Preferably, the α-olefin monomer is a C4-C42 α-olefin, and more preferably a C4-C20 α-olefin; Preferably, the structure of the acrylate monomer is as shown in formula (1); Equation (1), Wherein, R1 is hydrogen or methyl, and R2 is a straight-chain alkyl group of C1-C8, a branched alkyl group of C3-C8, or the structure shown in formula (2); Equation (2), Wherein, R3 is a C2-C3 alkylene group, R4 is hydrogen or methyl, and n is an integer from 1 to 5.

3. The copolymer according to claim 1 or 2, wherein, The content of the cross-linked structure accounts for 0.1 mol%-10 mol% of the total content of the three structural units A, B, and C, preferably 0.5 mol%-5 mol%. Preferably, the crosslinking monomer is selected from at least one of nonpolar dienes, polar haloacrylates, polar halovinyl acetates, polar halovinyl ethers, polar epoxy acrylates, and polar epoxy allyl ethers.

4. The copolymer according to any one of claims 1-3, wherein, The copolymer has a number average molecular weight of 20,000-400,000 g / mol, preferably 40,000-200,000 g / mol; Preferably, the copolymer has a molecular weight distribution of 1-10, more preferably 1-5.

5. A method for preparing the copolymer according to any one of claims 1-4, characterized in that, The method includes: mixing α-olefin monomers, acrylate monomers, Lewis acids, initiators, and crosslinking monomers in an organic solvent under polymerization reaction conditions, introducing ethylene monomers, and then polymerizing to obtain a polymer solution; the polymer solution is then precipitated and dried to obtain a copolymer. The amount of ethylene charged results in a polymerization pressure of 0.5-20 MPa, and the amount of α-olefin monomer used is 5-100 mol, based on the amount of acrylate monomer used.

6. The method for preparing the copolymer according to claim 5, wherein, The amount of ethylene charged results in a polymerization pressure of 1-10 MPa, and the amount of the α-olefin monomer is 5-50 mol% based on the amount of acrylate monomer used. Preferably, based on the amount of acrylate monomer used, the amount of Lewis acid is 0.001 mol%-200 mol%, more preferably 0.1 mol%-150 mol%, and even more preferably 1-120 mol%. Preferably, the Lewis acid is selected from metal oxides and / or halides; Preferably, the amount of the initiator is 0.001 mol%-5 mol% based on the amount of acrylate monomer, more preferably 0.01 mol%-1 mol%. Preferably, the initiator is selected from at least one of azo initiators, peroxide initiators, and redox initiators; Preferably, the organic solvent is selected from at least one of chloroform, dichloromethane, chlorobenzene, acetone, toluene, xylene, ethyl acetate, and tetrahydrofuran; Preferably, the polymerization temperature is 20-100℃, more preferably 30-80℃, and the polymerization time is 2-24h, more preferably 4-12h.

7. In the method for preparing the copolymer according to claim 5 or 6, the amount of the crosslinking monomer is 0.01 mol%-20 mol%, preferably 0.05 mol%-10 mol%, based on the amount of acrylate monomer used. Preferably, the crosslinking monomer is selected from at least one of nonpolar dienes, polar haloacrylates, polar halovinyl acetates, polar halovinyl ethers, polar epoxy acrylates, and polar epoxy allyl ethers.

8. A cross-linked elastomer material, characterized in that, The crosslinked elastomer material is obtained by vulcanization of the copolymer described in any one of claims 1-4.

9. The crosslinked elastomer material according to claim 8, wherein, The glass transition temperature of the crosslinked elastomer material is -40°C to 5°C, preferably -35°C to 0°C; Preferably, after aging in IRM901 standard oil at 100°C for 70 hours, the volume change percentage ΔV of the crosslinked elastomer material is less than or equal to 15%, and more preferably less than or equal to 10%. Preferably, the tensile strength of the crosslinked elastomer material is greater than or equal to 12 MPa, and more preferably greater than or equal to 15 MPa.

10. A method for preparing the crosslinked elastomer material according to claim 8 or 9, characterized in that, The method includes: mixing the copolymer, vulcanizing agent and filler to obtain a blend, and then vulcanizing the blend to obtain a crosslinked elastomer material.

11. The method according to claim 10, wherein, In the blend, the copolymer is 100 parts by weight, the filler is 10-100 parts by weight, preferably 30-100 parts by weight, and the vulcanizing agent is 0.1-10 parts by weight, preferably 1-5 parts by weight.

12. The application of the cross-linked elastomer material according to claim 8 or 9 as a sealing material or a damping material.

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