Ethylene-butadiene polymer, preparation method thereof and vulcanized rubber

Abstract

The invention relates to the field of synthetic rubber, and discloses an ethylene-butadiene polymer, a preparation method thereof and vulcanized rubber. The ethylene-butadiene polymer comprises a polyethylene chain segment and a butadiene rubber chain segment; based on the total weight of the ethylene-butadiene polymer, the content of the polyethylene chain segment is 0.1-40 wt%, and the content of the butadiene rubber chain segment is 60-99.9 wt%; in the butadiene rubber chain segment, based on the total amount of the butadiene rubber chain segment, the content of a cis-1, 4-structure is 90-98.5 mol%; based on the total weight of the ethylene-butadiene polymer, the content of toluene insoluble substances is 0.3-9 wt%. According to the ethylene-butadiene polymer, an ethylene structure chain segment is introduced into a butadiene structure chain segment of butadiene rubber, so that the butadiene rubber is modified, and the ethylene-butadiene polymer has improved tensile strength and tear resistance.

Description

Technical Field

[0001] The invention relates to the field of synthetic rubber, in particular to an ethylene-butadiene polymer and a preparation method thereof and a vulcanized rubber. Background Art

[0002] Butadiene rubber is a type of rubber material that is simply synthesized using cheap butadiene monomer as raw material. The molecular chain of butadiene rubber is regular and has no other substituent groups. Because it contains CC single bonds and a large number of free chains, the molecule is very soft. Its unique resilience, excellent wear resistance, cold resistance and dynamic performance have established its irreplaceable position in many fields such as tires, shoemaking, damping and shock absorption, and sealing industries. However, butadiene rubber also has shortcomings such as low tensile strength, tear strength and flexural strength, weak anti-slip properties, easy cold flow, and poor aging resistance, which limit its scope of application. Therefore, it is necessary to reinforce and modify butadiene rubber to overcome the shortcomings of butadiene rubber itself and expand the scope of application of butadiene rubber.

[0003] US4340685A discloses a cobalt and carbon disulfide catalyst system for in-situ synthesis of a blend of cis-1,4-polybutadiene / syndiotactic 1,2-polybutadiene and production of VCR rubber. The acidic gas generated by the use of carbon disulfide is highly corrosive to production equipment and the residue in the rubber has a certain impact on the performance.

[0004] CN105814132A discloses a method for synthesizing a polybutadiene composite material by in-situ blending of cis-1,4 polybutadiene and syndiotactic 1,2-polybutadiene. The in-situ copolymerization method requires the use of two catalytic systems during the polymerization process. In the first step, lanthanide catalysts are used to polymerize cis-1,4 polybutadiene, and then cobalt catalysts are used to add carbon disulfide to polymerize the cis-1,4 polybutadiene mixture to form syndiotactic 1,2-polybutadiene and thereby produce composite polybutadiene.

[0005] US9985115B2, US6291591B2 and US6331594B2 disclose the use of iron, chromium or molybdenum catalysts to polymerize butadiene in saturated alkanes of butadiene rubber to synthesize a blend of cis-1,4-polybutadiene / syndiotactic 1,2-polybutadiene. The above in-situ generated syndiotactic 1,2-polybutadiene is compounded with butadiene rubber solution. Since butadiene rubber is used as the dispersed phase, the polymerization activity is insufficient, the polymerization process is difficult to control, and the composition is difficult to adjust. More importantly, the two are not compatible, and phase separation and interface problems are easily generated, which affects the material properties.

[0006] At present, in order to improve the tensile strength, tear resistance, etc. of butadiene rubber products, thereby improving the performance and service life of butadiene rubber products, it is necessary to develop new butadiene rubber reinforcement technologies. Summary of the invention

[0007] The purpose of the present invention is to improve the tensile strength and tear resistance of existing cis-1,2-diene rubber materials, and to provide an ethylene-butadiene polymer and a preparation method thereof and a vulcanized rubber. In the ethylene-butadiene polymer, an ethylene structure segment is introduced into the butadiene structure segment of the cis-1,2-diene rubber to achieve modification of the cis-1,2-diene rubber, and the ethylene-butadiene polymer contains a specific content of toluene insoluble matter, so that the ethylene-butadiene polymer has improved tensile strength and tear resistance.

[0008] In order to achieve the above-mentioned object, the first aspect of the present invention provides an ethylene-butadiene polymer, wherein the ethylene-butadiene polymer comprises a polyethylene segment and a butadiene rubber segment; based on the total weight of the ethylene-butadiene polymer, the content of the polyethylene segment is 0.1-40wt%, and the content of the butadiene rubber segment is 60-99.9wt%; in the butadiene rubber segment, based on the total amount of the butadiene rubber segment, the content of cis-1,4-structure is 90-98.5mol%; based on the total weight of the butadiene rubber segment, the content of toluene insoluble matter is 0.2-10wt%.

[0009] A second aspect of the present invention provides a method for preparing an ethylene-butadiene polymer, the method comprising the following steps:

[0010] (1) in the presence of an organic solvent and a catalyst, initiating a polymerization reaction of butadiene monomer using an aluminum-containing cocatalyst-1 to obtain a polybutadiene product;

[0011] (2) adding the aluminum-containing co-catalyst-2 to the polymerization system obtained in step (1), and then introducing ethylene monomer to carry out copolymerization reaction with the polybutadiene active chain segment in the polybutadiene product to obtain the ethylene-butadiene polymer.

[0012] The third aspect of the present invention provides an ethylene-butadiene polymer prepared by the preparation method of the present invention.

[0013] A fourth aspect of the present invention provides a vulcanized rubber obtained from a composition comprising the ethylene-butadiene polymer of the present invention.

[0014] Through the above technical scheme, the ethylene-butadiene polymer and the preparation method thereof and the vulcanized rubber provided by the present invention achieve the following beneficial effects:

[0015] The ethylene-butadiene polymer provided by the present invention comprises a polyethylene segment and a butadiene rubber segment, and an ethylene structure segment is introduced into the butadiene structure segment of the butadiene rubber to achieve modification of the butadiene rubber. This chemical linking method effectively avoids the problems of phase separation, interface failure, etc. caused by directly blending polyethylene and butadiene rubber in a traditional process, and the polymer contains a specific content of toluene insoluble matter, so that the vulcanized rubber prepared from the composition comprising the ethylene-butadiene polymer has improved tensile strength and tear resistance.

[0016] In the method for preparing an ethylene-butadiene polymer provided by the present invention, a one-step polymerization process is adopted in the presence of a catalyst to simultaneously realize the synthesis of two traditional polymers, polyethylene and butadiene rubber, and the ethylene-butadiene polymer comprising polyethylene segments and butadiene rubber according to the present invention is obtained by in-situ polymerization. Meanwhile, compared with step-by-step polymerization, the preparation method provided by the present invention has the advantages of simple process, strong operability, low cost, easier adjustment of the polymerization process and the composition of the composite material, etc., and is conducive to industrial production. DETAILED DESCRIPTION

[0017] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0018] The first aspect of the present invention provides an ethylene-butadiene polymer, characterized in that the ethylene-butadiene polymer comprises a polyethylene segment and a butadiene rubber segment; based on the total weight of the ethylene-butadiene polymer, the content of the polyethylene segment is 0.1-40wt%, and the content of the butadiene rubber segment is 60-99.9wt%; in the butadiene rubber segment, based on the total molar amount of the butadiene rubber segment, the content of the cis-1,4-structure is 90-98.5mol%;

[0019] The content of toluene insoluble matter is 0.2-10 wt % based on the total weight of the ethylene-butadiene polymer.

[0020] In the present invention, the ethylene-butadiene polymer comprises a polyethylene segment and a butadiene rubber segment, and an ethylene structure segment is introduced into the butadiene structure segment of the butadiene rubber, thereby realizing modification of the butadiene rubber, so that the polyethylene phase of the reinforcement body and the butadiene rubber of the matrix have excellent compatibility, thereby avoiding the problems of phase separation and interface failure caused by directly blending polyethylene with butadiene rubber in the traditional process, and the polymer contains a specific content of toluene insoluble matter, thereby realizing reinforcement of the vulcanized rubber, and making the vulcanized rubber prepared from the composition comprising the ethylene-butadiene polymer have improved tensile strength and tear resistance.

[0021] Furthermore, when the content of the polyethylene segment in the ethylene-butadiene polymer, the content of the butadiene rubber segment, and the content of the cis-1,4 structure in the butadiene rubber meet the above ranges, the tensile strength and tear strength of the vulcanized rubber prepared from the composition containing the ethylene-butadiene polymer can be further improved.

[0022] In the present invention, the toluene insoluble matter refers to the components insoluble in toluene in the ethylene-isoprene polymer when tested according to SH / T 1050-2014.

[0023] In the present invention, the content of toluene insoluble matter in the ethylene-isoprene polymer is measured with reference to SH / T1050-2014.

[0024] In some preferred embodiments of the present invention, preferably, based on the total weight of the ethylene-butadiene polymer, the content of the polyethylene segment is 1-35 wt%, and the content of the butadiene rubber segment is 65-99 wt%.

[0025] In some preferred embodiments of the present invention, preferably, in the butadiene rubber segment, based on the total molar amount of the butadiene rubber segment, the content of cis-1,4-structure is 92-98 mol%.

[0026] In some preferred embodiments of the present invention, preferably, based on the total weight of the ethylene-butadiene polymer, the content of toluene insoluble matter is 0.3-9 wt %.

[0027] In the present invention, the content of polyethylene segment and cis-1,4-butadiene segment in the ethylene-butadiene polymer and the content of cis-1,4-structure in the cis-1,4-butadiene rubber segment are measured by hydrogen nuclear magnetic spectrum.

[0028] In some preferred embodiments of the present invention, preferably, the number average molecular weight of the ethylene-butadiene polymer is 50,000-700,000, preferably 80,000-500,000.

[0029] In some preferred embodiments of the present invention, preferably, the molecular weight distribution of the ethylene-butadiene polymer is 2-5, preferably 2.5-4.5.

[0030] In the present invention, the number average molecular weight and molecular weight distribution of the ethylene-butadiene polymer are measured by GPC method.

[0031] In some preferred embodiments of the present invention, the total weight of the toluene insoluble matter, wherein the content of polyethylene segments is 85-95 wt %.

[0032] In the present invention, the polyethylene segment content in the toluene insoluble matter is measured by hydrogen nuclear magnetic spectrum.

[0033] In the present invention, when the content of the polyethylene segment in the toluene insoluble matter meets the above range, it is beneficial to achieve effective compatibility of the polyethylene segment and the isoprene segment in the ethylene-butadiene polymer without phase separation, thereby further improving the tensile strength and tear strength of the obtained vulcanized rubber.

[0034] A second aspect of the present invention provides a method for preparing an ethylene-butadiene polymer, characterized in that the method comprises the following steps:

[0035] (1) in the presence of an organic solvent and a catalyst, initiating a polymerization reaction of butadiene monomer using an aluminum-containing cocatalyst-1 to obtain a polybutadiene product;

[0036] (2) adding the aluminum-containing co-catalyst-2 to the polymerization system obtained in step (1), and then introducing ethylene monomer to carry out copolymerization reaction with the polybutadiene active chain segment in the polybutadiene product to obtain the ethylene-butadiene polymer.

[0037] In the method for preparing ethylene-butadiene polymer described in the present invention, a one-step polymerization process is adopted in the presence of a catalyst to simultaneously realize the synthesis of two traditional polymers, polyethylene and butadiene rubber, and the ethylene-butadiene polymer comprising polyethylene segments and butadiene rubber described in the present invention is obtained by in-situ polymerization. In the butadiene rubber, the polyethylene segments and the polybutadiene segments are bonded together by chemical bonds, which significantly improves the comprehensive properties of the butadiene rubber, especially the tensile properties and tear resistance.

[0038] At the same time, compared with step-by-step polymerization, the preparation method provided by the present invention has the advantages of simple process, strong operability, low cost, easier adjustment of the polymerization process and the composition of the composite material, etc., which is conducive to industrial production.

[0039] Specifically, by adopting the method provided by the present invention, the ethylene-butadiene polymer containing a specific content of polyethylene segments and butadiene rubber segments as described in the first aspect of the present invention can be obtained, and the butadiene rubber contains a specific content of cis-1,4-structure.

[0040] In some embodiments of the present invention, the polymerization reaction of butadiene can be carried out first, and then the copolymerization reaction of polybutadiene and ethylene monomer can be carried out. The two reaction processes can be carried out continuously, and the same catalyst can be used in the polymerization reaction and the copolymerization reaction, and then different monomers can be initiated with different co-catalysts to achieve the reaction synthesis of different monomers to form corresponding segments.

[0041] In some embodiments of the present invention, preferably, the catalyst is a cobalt-based catalyst containing a cobalt organic compound.

[0042] In some embodiments of the present invention, preferably, in step (1), the catalyst is selected from at least one of the compound represented by Formula 1, the compound represented by Formula 2 and the compound represented by Formula 3:

[0043]

[0044]

[0045] Wherein, X is chlorine or bromine;

[0046] R1 is H, or a monosubstituted substituent at position 2 or 4 on the benzene ring, or the same or different substituents at positions 2, 4 or 2, 6 on the benzene ring, or the same or different substituents at positions 2, 4, and 6 on the benzene ring, and the substituent is -F, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2;

[0047] R3 is H, or -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2 which are monosubstituted at the 6-position of the pyridine ring, or -CH3, -N(CH3)2 or -CF3 which are monosubstituted at the 4-position of the pyridine ring, or -CH3, -CH2CH3, -C6H5, -CH(C6H5)2, -N(CH3)2 or -CF3 which are disubstituted at the 4- and 6-positions of the pyridine ring, which are the same or different;

[0048] R5 is H, or -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2 which is monosubstituted at the 4-position of the dihydrooxazole ring;

[0049] R2, R4, and R6 are each independently hydrogen, or -Cl, -F, -CH3, -OCH3, -N(CH3)2, or -CF3 which is monosubstituted at the 4-position of the pyridine ring.

[0050] In some embodiments of the present invention, R1 represents a substituent on the benzene ring in Formula 1, and multiple substitution positions on the benzene ring are allowed to be all H, preferably R1 is H; or R1 represents that some of the substitution positions on the benzene ring are substituents other than H, as described above, the 2nd or 4th position on the benzene ring is monosubstituted, or the 2nd, 4th or 2nd, 6th positions on the benzene ring are disubstituted, or the 2nd, 4th, 6th positions on the benzene ring are trisubstituted, and the other substitution positions are H, wherein the substituents may be the same or different in the case of disubstituted and trisubstituted, preferably -F, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C 6H5 or -CH(C6H5)2, or -F, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2 disubstituted at the 2, 4 or 2, 6 positions on the benzene ring, or -F, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2 trisubstituted at the 2, 4, 6 positions on the benzene ring, more specifically, one of the following groups represented by the substitution position on the benzene ring: 2-F-, 2-CH3-, 4-F-, 4-CH3-, 2,4- F-, 2,4-CH3-, 2,6-F-, 2,6-CH3-, 2,4,6-F-, 2,4,6-CH3-, 2-CH2CH3-, 4-CH2CH3-, 2,4-CH2CH3-, 2-CH2CH3-4-CH3-, 2,6-C H2CH3-, 2-CH2CH3-6-CH3-, 2,4,6-CH2CH3-, 2-CH(CH3)2-, 4-CH(CH3)2-, 2,4-CH(CH3)2-, 2,6-CH(CH3)2-, 2,4,6-CH(CH3) 2-, 2-C(CH3)3-, 4-C(CH3)3-, 2,4-C(CH3)3-, 2,6-C(CH3)3-, 2-C(CH3)3-6-CH3-, 2,4,6-C(CH3)3-, 2-C6H5-, 4-C6H5-, 2,4-C6H5-, 2,6-C6H5-, 2,4,6-C6H5-, 2-CH(C6H5)2-, 4-CH(C6H5)2-, 2,4-CH(C6H5)2-, 2,6-CH(C6H5)2-, 2,4,6-CH(C6H5)2-. In the present invention, the number in front of the substituent refers to the substitution position on the benzene ring. For example, 2-F- refers to -F substituted at the 2nd position on the benzene ring.

[0051] In some embodiments of the present invention, R3 represents a substituent on the pyridine ring (different from the pyridine ring substituted by R4) in Formula 2, and multiple substitution positions on the pyridine ring are allowed to be all H, preferably R3 is H; or R3 represents that some of the substitution positions on the pyridine ring are substituents other than H, as described above, the 4 or 6 position on the pyridine ring is monosubstituted, or the 4 and 6 positions on the pyridine ring are disubstituted, and the substitution position is H, wherein, when disubstituted, the substituents may be the same or different, preferably, the 6 position on the pyridine ring is monosubstituted by -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2, or the 4 position on the pyridine ring is monosubstituted by -CH3, -N(CH3)2 or -CF3, or the 4 and 6 positions on the pyridine ring are disubstituted by -CH3, -CH2CH3, -C6H5, -CH(C6H5)2, -N(CH3)2 or -CF3, more specifically, one of the following groups represented by the substitution position on the pyridine ring: 6-CH3-, 6-CH2CH3-, 6-C6H5-, 6-CH(C6H5)2-, 4-CH3-, 4-N(CH3)2-, 4-CF3-, 4,6-CH3-, 4-CH3-6-CH2CH3-, 4-CH3-6-C6H5-, 4-CH3-6-CH(C In the present invention, the number in front of the substituent refers to the substitution position on the pyridine ring. For example, 6-CH3- refers to the substitution -CH3 at the 6th position on the pyridine ring.

[0052] In some embodiments of the present invention, R5 represents a substituent on the dihydrooxazole ring in Formula 3, and multiple substitution positions on the dihydrooxazole ring are allowed to be all H, preferably R3 is H; or R3 represents that some of the substitution positions on the dihydrooxazole ring are substituents other than H. As mentioned above, the 4-position on the dihydrooxazole ring is monosubstituted, and the other substitution positions are H. Preferably, the 4-position on the dihydrooxazole ring is monosubstituted with -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2, more specifically, one of the following groups represented by the substitution position on the dihydrooxazole ring: 4-CH3-, 4-CH2CH3-, 4-CH(CH3)2-, 4-C(CH3)3-, 4-C6H5-, 4-CH(C6H5)2-. In the present invention, the number before the substituent refers to the substitution position on the dihydrooxazole ring. For example, 4-CH3- refers to -CH3 substituted at the 4-position on the dihydrooxazole ring.

[0053] In some embodiments of the present invention, R2, R4, and R6 each independently represent a substituent on the pyridine ring in Formulas 1, 2, and 3 (different from the pyridine ring substituted by R3 in Formula 2), and multiple substitution positions on the pyridine ring substituted by R2, R4, and R6 are allowed to be all H, preferably R2, R4, and R6 are H; or, R2, R4, and R6 represent -Cl, -F, -CH3, -OCH3, -N(CH3)2, or -CF3 substituted at position 4 on the substituted pyridine ring, more specifically, one of the following groups represented by the substitution position on the pyridine ring: 4-Cl-, 4-F-, 4-CH3-, 4-OCH3-, 4-N(CH3)2-, 4-CF3-. In the present invention, the number in front of the substituent refers to the substitution position on the pyridine ring. For example, 4-Cl- refers to -Cl substituted at position 4 on the pyridine ring.

[0054] In some embodiments of the present invention, preferably, the molar ratio of the catalyst, the aluminum-containing co-catalyst-1 and the aluminum-containing co-catalyst 2 is 1:20-1000:15-1000, preferably 1:40-900:20-900.

[0055] In the present invention, when the molar ratio of the catalyst, the aluminum-containing co-catalyst-1 and the aluminum-containing co-catalyst-2 is controlled to meet the above range, the reaction activities of the polymerization reaction and the copolymerization reaction in steps (1) and (2) can be controlled, thereby achieving control of the content of the polyethylene segment and the butadiene rubber segment in the ethylene-butadiene polymer, and the content of the cis-1,4-structure in the butadiene rubber.

[0056] In some specific embodiments of the present invention, preferably, the amount of the catalyst is 0.1-1.6 mmoL, preferably 0.15-1.2 mmoL, relative to 1 mol of butadiene. In the present invention, the amount of the catalyst and butadiene is controlled to satisfy the above relationship, which can ensure the polymerization activity of butadiene and achieve the regulation of the content of each segment in the polymer.

[0057] In some specific embodiments of the present invention, preferably, the organic solvent is selected from at least one of n-pentane, neopentane, n-hexane, cyclohexane, n-heptane, n-octane, isooctane, benzene, toluene, decahydronaphthalene, dodecane and hydrogenated gasoline, preferably toluene.

[0058] In some specific embodiments of the present invention, preferably, the polymerization reaction conditions include: polymerization reaction temperature of 30-70°C, preferably 40-60°C; polymerization reaction pressure of 1-10 bar, preferably 2-5 bar; polymerization reaction time of 1-6h, preferably 2-5h. In the present invention, the polymerization reaction pressure of step (1) can be the gas phase pressure of the fed butadiene monomer.

[0059] In some specific embodiments of the present invention, preferably, the copolymerization reaction conditions include: copolymerization reaction temperature of 20-70°C, preferably 30-60°C; copolymerization reaction pressure of 1-70 bar, preferably 5-50 bar; copolymerization reaction time of 1-80 min, preferably 5-60 min. In the present invention, the copolymerization reaction pressure in step (2) can be the gas phase pressure of the fed ethylene monomer.

[0060] In some embodiments of the present invention, the amount relationship between ethylene monomer and butadiene can be controlled by the time and pressure of the ethylene monomer being introduced into the reaction, thereby obtaining an ethylene-butadiene polymer with cis-1,4-butadiene rubber as an elastomer matrix and polyethylene as a reinforcing phase. Preferably, the feed weight relationship of ethylene monomer and butadiene monomer satisfies the amount of the corresponding polyethylene segment and cis-1,4-butadiene rubber segment in the obtained ethylene-butadiene polymer, for example, based on the total weight of the ethylene-butadiene polymer, the content of the polyethylene segment is 0.1-40wt%, preferably 1-35wt%, and the content of the polyisoprene segment is 60-99.9wt%, preferably 65-99wt%; based on the total molar amount of the cis-1,4-butadiene rubber segment, the content of the cis-1,4-structure is 90-98.5mol%, preferably 92-98mol%.

[0061] In some specific embodiments of the present invention, preferably, the aluminum-containing cocatalyst-1 is selected from at least one of diethylaluminum chloride, ethylaluminum sesquichloride, di-n-propylaluminum chloride, diisopropylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, di-n-octylaluminum chloride, ethylaluminum dichloride, n-propylaluminum dichloride, isopropylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride, n-octylaluminum dichloride, methylaluminoxane (MAO) and triisobutylaluminum-modified methylaluminoxane (MMAO), preferably at least one of diisobutylaluminum chloride, diethylaluminum chloride, ethylaluminum sesquichloride and methylaluminoxane. In the present invention, under the joint action of the catalyst and the aluminum-containing cocatalyst-1, the polymerization reaction of butadiene monomer is initiated.

[0062] In some embodiments of the present invention, preferably, the aluminum-containing cocatalyst-2 is selected from at least one of methylaluminoxane (MAO), triisobutylaluminum-modified methylaluminoxane (MMAO), diethylaluminum chloride, sesquiethylaluminum, di-n-propylaluminum chloride, diisopropylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, di-n-octylaluminum chloride, ethylaluminum dichloride, n-propylaluminum dichloride, isopropylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride and n-octylaluminum dichloride, preferably selected from at least one of methylaluminoxane, triisobutylaluminum-modified methylaluminoxane, diisobutylaluminum chloride, diethylaluminum chloride and sesquiethylaluminum. In the present invention, under the joint action of the catalyst and the aluminum-containing cocatalyst-2, the copolymerization reaction of the active chain segments of the ethylene monomer and the polybutadiene is initiated.

[0063] In the present invention, when the copolymerization reaction needs to be terminated, the following steps may also be performed:

[0064] When the copolymerization reaction reaches a suitable time, a stabilizer and a terminator are added in sequence to terminate the copolymerization reaction, and then the obtained product is washed and vacuum dried to obtain the ethylene-reinforced butadiene rubber.

[0065] The stabilizer may be a reagent that has an antioxidant effect, and may be a toluene solution of 2,2-methylenebis-(4-methyl-6-tert-butylphenol) with a mass concentration of 5%, and may be added in an amount of 0.5%-1.0% of the total weight of the monomer. The terminator may be a reagent that terminates polymerization and removes residual catalysts, and may be a methanol solution of hydrochloric acid with a mass concentration of 4%, and may be added in an amount of 0.1%-1.0% of the total weight of the monomer. The washing process may be using a methanol solution and water in sequence for about 3 times.

[0066] In one specific embodiment of the present invention, the method for preparing the ethylene-butadiene polymer specifically comprises the following steps:

[0067] The reaction equipment is used to purify the polymerization reaction environment using a double-row pipe operation technology; the cobalt-based catalyst and the organic solvent provided by the present invention are added to the reaction equipment, stirred and dispersed evenly, and heated to a set temperature; then butadiene monomer is added to the reaction equipment, and then a set amount of aluminum-containing co-catalyst-1 is added to initiate the polymerization reaction of butadiene for a set time;

[0068] After reaching the set polymerization reaction time, add aluminum-containing co-catalyst-2, and introduce 1-70 bar ethylene gas to initiate copolymerization of ethylene monomer and polybutadiene active chain segments. Maintain constant pressure until the set time according to the different ethylene chain segment content in the final ethylene-butadiene polymer.

[0069] Finally, a stabilizer and a terminator are added to terminate the reaction; the obtained product is then washed three times with a methanol solution and vacuum dried to obtain the polyethylene in-situ reinforced butadiene rubber.

[0070] The third aspect of the present invention provides an ethylene-butadiene polymer obtained by the method of the present invention.

[0071] In the present invention, the ethylene-butadiene polymer is as described in the first aspect of the present invention, and will not be described again here to avoid repetition.

[0072] A fourth aspect of the present invention provides a vulcanized rubber prepared from a composition comprising the ethylene-butadiene polymer of the present invention.

[0073] The present invention will be described in detail below by way of examples. In the following examples,

[0074] The content of polyethylene segments in ethylene-butadiene polymer, the content of butadiene rubber segments, the content of cis-1,4-structure in butadiene rubber and the content of polyethylene segments in toluene insoluble matter were measured by nuclear magnetic resonance spectroscopy.

[0075] The number average molecular weight and molecular weight distribution of ethylene-butadiene polymers were measured by GPC.

[0076] The test of toluene insoluble content refers to SH / T 1050-2014: Cut thin strips of the obtained polymer sample at multiple points, weigh about 0.3g (accurate to 0.1mg), and spread them flat on the filter with constant weight to prevent the strips from sticking. Add about 100ml of toluene to the weighing bottle and suspend the filter in the weighing bottle. Cover the weighing bottle cap and dissolve it on an oscillator at room temperature for 48 hours. Then take out the filter, rinse it several times, vacuum dry it, and weigh it.

[0077] The raw materials used in the examples and comparative examples are all commercially available.

[0078] Example 1

[0079] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH(CH3)2- (other substitution positions on the benzene ring are hydrogen), R2 is H (all substitution positions on the pyridine ring are hydrogen), and X is chlorine) (2.260mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 45°C, 300g of 1,3-butadiene is added, and a constant pressure (3bar) atmosphere is maintained, and diisobutylaluminum chloride (0.679mol) is injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature is 45°C and the polymerization reaction time is 2h;

[0080] The temperature of the mixed system was controlled at 30°C, and ethylene monomer was introduced to maintain a constant pressure (10 bar) atmosphere, and then methylaluminoxane (MAO) (0.679 mol) was added to initiate copolymerization of ethylene and polybutadiene. The polymerization temperature was 30°C, and the introduction of ethylene monomer was stopped after polymerization for 10 minutes.

[0081] Then, a toluene solution of 2,2-methylenebis-(4-methyl-6-tert-butylphenol) with a mass concentration of 5% was added as a stabilizer, and 20 mL of a methanol solution of hydrochloric acid with a mass concentration of 4% was added to the polymerization system to terminate the reaction. Finally, the polymerization product was washed with methanol three times and vacuum dried to obtain 282.8 g of ethylene-butadiene polymer.

[0082] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1650, 736 characteristic peaks of cis-1,4-butadiene rubber, 720 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 7.3wt%, cis-1,4-butadiene rubber segment content is 92.7wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 96.5mol%;

[0083] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 220,000 and the molecular weight distribution is 3.08.

[0084] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 1 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 93.2 wt %.

[0085] Example 2

[0086] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH(CH3)2- (other substitution positions on the benzene ring are hydrogen), R2 is 4-OCH3- (while other substitution positions on the pyridine ring are hydrogen), and X is chlorine) (2.260mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 42°C, 500g of 1,3-butadiene is added, and a constant pressure (2.5bar) atmosphere is maintained, and diisobutylaluminum chloride (0.679mol) is injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature is 42°C, and the polymerization reaction time is 3h;

[0087] The temperature of the mixed system was controlled at 39°C, and ethylene monomer was introduced to maintain a constant pressure (7 bar) atmosphere, and then methylaluminoxane (MAO) (0.452 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 39°C, and the introduction of ethylene monomer was stopped after 6 minutes of copolymerization.

[0088] The polymerization product was post-treated according to the method of Example 1 to obtain 454.1 g of ethylene-butadiene polymer.

[0089] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1644, 734 characteristic peaks of cis-1,4-butadiene rubber, 719 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 1.7wt%, cis-1,4-butadiene rubber segment content is 98.3wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 98mol%;

[0090] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 363,000 and the molecular weight distribution is 2.79.

[0091] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 0.3 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 94.8 wt %.

[0092] Example 3

[0093] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 3 L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,4,6-CH3- (other substitution positions on the benzene ring are hydrogen), R2 is 4-F- (while other substitution positions on the pyridine ring are hydrogen), and X is chlorine) (2.260 mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 48° C., 650 g of 1,3-butadiene is added, and a constant pressure (3.2 bar) atmosphere is maintained, and diisobutylaluminum chloride (0.679 mol) is injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature is 48° C., and the polymerization reaction time is 3.5 h;

[0094] The temperature of the mixed system was controlled at 35°C, and ethylene monomer was introduced to maintain a constant pressure (15 bar) atmosphere, and then diethylaluminum chloride (0.113 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 35°C, the copolymerization time was 25 min, and then the introduction of ethylene monomer was stopped;

[0095] The polymerization product was post-treated according to the method of Example 1 to obtain 607.9 g of ethylene-butadiene polymer.

[0096] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1644, 738 characteristic peaks of cis-1,4-butadiene rubber, 720 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.1 ethylene segment peak); polyethylene segment content is 3.6wt%, cis-1,4-butadiene rubber segment content is 96.4wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 97mol%;

[0097] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 479,000 and the molecular weight distribution is 2.95.

[0098] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 0.9 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 94.1 wt %.

[0099] Example 4

[0100] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH2CH3- (other substitution positions on the benzene ring are hydrogen), R2 is 4-CH3- (while other substitution positions on the pyridine ring are hydrogen), and X is bromine) (2.260mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 52°C, 200g of 1,3-butadiene is added, and a constant pressure (4bar) atmosphere is maintained, and diisobutylaluminum chloride (1.131mol) is injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature is 43°C, and the polymerization reaction time is 4h;

[0101] The temperature of the mixed system was controlled at 40°C, and ethylene monomer was introduced to maintain a constant pressure (8.5 bar) atmosphere, and then methylaluminoxane (MAO) (1.131 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 40°C, and the copolymerization time was 9 minutes, after which the introduction of ethylene monomer was stopped;

[0102] The polymerization product was post-treated according to the method of Example 1 to obtain 202.9 g of ethylene-butadiene polymer.

[0103] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1)(1649, 741 characteristic peaks of cis-1,4-butadiene rubber, 721 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 for cis-1,4-butadiene rubber peak, 1.10 for ethylene segment peak); polyethylene segment content is 10.3wt%, cis-1,4-butadiene rubber segment content is 89.7wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 96.1mol%;

[0104] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 148,000 and the molecular weight distribution is 3.31.

[0105] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 1.3 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 92.3 wt %.

[0106] Example 5

[0107] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2 L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH2CH3- (other substitution positions on the benzene ring are hydrogen), R2 is 4-Cl- (while other substitution positions on the pyridine ring are hydrogen), and X is chlorine) (2.260 mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 53° C., 280 g of 1,3-butadiene is added, and a constant pressure (3 bar) atmosphere is maintained, and diisobutylaluminum chloride (1.584 mol) is injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature is 53° C. and the polymerization reaction time is 3 h;

[0108] The temperature of the mixed system was controlled at 33°C, and ethylene monomer was introduced to maintain a constant pressure (5 bar) atmosphere, and then methylaluminoxane (MAO) (1.584 mol) was added to initiate copolymerization of ethylene and polybutadiene. The polymerization temperature was 33°C, and the introduction of ethylene monomer was stopped after 20 minutes of polymerization.

[0109] The polymerization product was post-treated according to the method of Example 1 to obtain 277.5 g of ethylene-butadiene polymer.

[0110] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1648, 737 characteristic peaks of cis-1,4-butadiene rubber, 723 wavenumber of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 5.4wt%, cis-1,4-butadiene rubber segment content is 94.6wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 97.1mol%;

[0111] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 198,000 and the molecular weight distribution is 3.02.

[0112] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 0.7 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 93.6 wt %.

[0113] Example 6

[0114] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 2 L of toluene and a catalyst as shown in Formula 2 (wherein R3 is 4,6-CH3- (other substitution positions on the pyridine ring substituted by R3 are hydrogen), R4 is hydrogen (all substitution positions on the pyridine ring substituted by R4 are hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was uniformly dispersed by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 58° C., 300 g of 1,3-butadiene was added, and a constant pressure (3.5 bar) atmosphere was maintained, and diisobutylaluminum chloride (1.131 mol) was injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature was 58° C. and the polymerization reaction time was 4 h;

[0115] The temperature of the mixed system was controlled at 60°C, and ethylene monomer was introduced to maintain a constant pressure (50 bar) atmosphere, and then methylaluminoxane (MAO) (1.131 mol) was added to initiate copolymerization of ethylene and polybutadiene. The polymerization temperature was 60°C, and the polymerization reaction time was 19 min, after which the introduction of ethylene monomer was stopped;

[0116] The polymerization product was post-treated according to the method of Example 1 to obtain 451.8 g of ethylene-butadiene polymer.

[0117] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1639, 739 characteristic peaks of cis-1,4-butadiene rubber, 720 wavenumber of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 25.1wt%, cis-1,4-butadiene rubber segment content is 74.9wt%; in cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 93.7mol%;

[0118] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 275,000 and the molecular weight distribution is 3.98.

[0119] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 5.1 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 87.1 wt %.

[0120] Example 7

[0121] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2L of toluene and the catalyst shown in Formula 2 (wherein R3 is 4-N(CH3)2-6-CH2CH3- (other substitution positions on the pyridine ring substituted by R3 are hydrogen), R4 is 4-OCH3- (while other substitution positions on the pyridine ring substituted by R4 are hydrogen), and X is bromine) (2.260mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 60°C, 460g of 1,3-butadiene is added, and a constant pressure (3.5bar) atmosphere is maintained, and diisobutylaluminum chloride (0.684mol) is injected to initiate a butadiene polymerization reaction, the polymerization reaction temperature is 60°C, and the polymerization reaction time is 4.8h;

[0122] The temperature of the mixed system was controlled at 50°C, and ethylene monomer was introduced to maintain a constant pressure (30 bar) atmosphere, and then diethylaluminum chloride (0.684 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 50°C, and the copolymerization reaction time was 40 min, after which the introduction of ethylene monomer was stopped;

[0123] The polymerization product was post-treated according to the method of Example 1 to obtain 588.0 g of ethylene-butadiene polymer.

[0124] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1649, 729 characteristic peaks of cis-1,4-butadiene rubber, 719 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 for cis-1,4-butadiene rubber peak, 1.10 for ethylene segment peak); polyethylene segment content is 28.5wt%, cis-1,4-butadiene rubber segment content is 71.5wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 93.6mol%;

[0125] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 474,000 and the molecular weight distribution is 4.11.

[0126] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 8.4 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 86.4 wt %.

[0127] Example 8

[0128] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2 L of toluene and the catalyst shown in Formula 2 (wherein R3 is 4-CF3-6-C6H5- (other substitution positions on the pyridine ring substituted by R3 are hydrogen), R4 is 4-F- (while other substitution positions on the pyridine ring substituted by R4 are hydrogen), and X is chlorine) (2.260 mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 55° C., 180 g of 1,3-butadiene is added, and a constant pressure (2.5 bar) atmosphere is maintained, and diisobutylaluminum chloride (1.584 mol) is injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature is 55° C. and the polymerization reaction time is 3.2 h;

[0129] The temperature of the mixed system was controlled at 55°C, and ethylene monomer was introduced to maintain a constant pressure (20 bar) atmosphere, and then methylaluminoxane (MAO) (1.584 mol) was added to initiate the polymerization of ethylene and polybutadiene. The polymerization temperature was 55°C, and the copolymerization reaction time was 30 min, after which the introduction of ethylene monomer was stopped;

[0130] The polymerization product was post-treated according to the method of Example 1 to obtain 228.9 g of ethylene-butadiene polymer.

[0131] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1646, 741 characteristic peaks of cis-1,4-butadiene rubber, 722 wavenumber of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 31.6wt%, cis-1,4-butadiene rubber segment content is 68.4wt%; in cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 93.2mol%;

[0132] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 153,000 and the molecular weight distribution is 4.25.

[0133] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 5.3 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 85.7 wt %.

[0134] Example 9

[0135] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 1 L of toluene and a catalyst as shown in Formula 2 (wherein R3 is 6-CH(C6H5)2- (other substitution positions on the pyridine ring substituted by R3 are hydrogen), R4 is 4-Cl (other substitution positions on the pyridine ring substituted by R4 are hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was uniformly dispersed by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 50° C., 150 g of 1,3-butadiene was added, and a constant pressure (2.5 bar) atmosphere was maintained, and methylaluminoxane (MAO) (0.678 mol) was injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature was 50° C. and the polymerization reaction time was 2.4 h;

[0136] The temperature of the mixed system was controlled at 47°C, and ethylene monomer was introduced to maintain a constant pressure (15 bar) atmosphere, and then methylaluminoxane (MAO) (0.452 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 47°C, and the copolymerization reaction time was 15 min. The introduction of ethylene monomer was stopped;

[0137] The polymerization product was post-treated according to the method of Example 1 to obtain 146.3 g of ethylene-butadiene polymer.

[0138] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1647, 731 characteristic peaks of cis-1,4-butadiene rubber, 720 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 13.9wt%, cis-1,4-butadiene rubber segment content is 86.1wt%; in cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 96mol%;

[0139] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 101,000 and the molecular weight distribution is 3.45.

[0140] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 1.6 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 91.5 wt %.

[0141] Example 10

[0142] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 2 L of toluene and a catalyst as shown in Formula 3 (wherein R5 is 4-CH3- (other substitution positions on the dihydrooxazole ring are hydrogen), R6 is H (other substitution positions on the pyridine ring are hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 48° C., 190 g of 1,3-butadiene was added, and a constant pressure (2.7 bar) atmosphere was maintained, and methylaluminoxane (MAO) (0.678 mol) was injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature was 50° C., and the polymerization reaction time was 4.2 h;

[0143] The temperature of the mixed system was controlled at 32°C, and ethylene monomer was introduced to maintain a constant pressure (25 bar) atmosphere, and then methylaluminoxane (MAO) (0.452 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 32°C, and the copolymerization reaction time was 25 min, and then the introduction of ethylene monomer was stopped;

[0144] The polymerization product was post-treated according to the method of Example 1 to obtain 210.8 g of ethylene-butadiene polymer.

[0145] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1648, 741 characteristic peaks of cis-1,4-butadiene rubber, 721 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 for cis-1,4-butadiene rubber peak, 1.10 for ethylene segment peak); polyethylene segment content is 22.5wt%, cis-1,4-butadiene rubber segment content is 77.5wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 94mol%;

[0146] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 148,000 and the molecular weight distribution is 3.83.

[0147] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 3.2 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 88.2 wt %.

[0148] Embodiment 11

[0149] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 3 L of toluene and a catalyst as shown in Formula 3 (wherein R5 is 4-CH2CH3- (other substituents on the dihydrooxazole ring are hydrogen), R6 is 4-CH3- (while other substituents on the pyridine ring are hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 45° C., 410 g of 1,3-butadiene was added, and a constant pressure (2.5 bar) atmosphere was maintained, and diisobutylaluminum chloride (0.226 mol) was injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature was 45° C. and the polymerization reaction time was 5 h;

[0150] The temperature of the mixed system was controlled at 42°C, and ethylene monomer was introduced to maintain a constant pressure (6 bar) atmosphere, and then methylaluminoxane (MAO) (0.339 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 42°C, the copolymerization time was 50 min, and then the introduction of ethylene monomer was stopped;

[0151] The polymerization product was post-treated according to the method of Example 1 to obtain 383.5 g of ethylene-butadiene polymer.

[0152] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1647, 738 characteristic peaks of cis-1,4-butadiene rubber, 721 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 for cis-1,4-butadiene rubber peak, 1.10 for ethylene segment peak); polyethylene segment content is 11.3wt%, cis-1,4-butadiene rubber segment content is 88.7wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 95.9mol%;

[0153] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 258,000 and the molecular weight distribution is 3.42.

[0154] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 2.0 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 92.1 wt %.

[0155] Example 12

[0156] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 4 L of toluene and a catalyst as shown in Formula 3 (wherein R5 is 4-CH(CH3)2- (other substituents on the dihydrooxazole ring are hydrogen), R6 is 4-OCH3- (while other substituents on the pyridine ring are hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was uniformly dispersed by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 45° C., 150 g of 1,3-butadiene was added, and a constant pressure (2.7 bar) atmosphere was maintained, and diisobutylaluminum chloride (0.113 mol) was injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature was 45° C., and the polymerization reaction time was 4.5 h;

[0157] The temperature of the mixed system was controlled at 50°C, and ethylene monomer was introduced to maintain a constant pressure (40 bar) atmosphere, and then sesquiethylaluminum (0.904 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization reaction temperature was 50°C, the copolymerization reaction time was 22 min, and then the introduction of ethylene monomer was stopped;

[0158] The polymerization product was post-treated according to the method of Example 1 to obtain 186.9 g of ethylene-butadiene polymer.

[0159] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1649, 733 characteristic peaks of cis-1,4-butadiene rubber, 722 wavenumber of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 34.2wt%, cis-1,4-butadiene rubber segment content is 65.8wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 92.3mol%;

[0160] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 138,000 and the molecular weight distribution is 4.35.

[0161] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 4.3 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 85.2 wt %.

[0162] Example 13

[0163] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 2 L of toluene and a catalyst as shown in Formula 3 (wherein R5 is 4-C6H5- (other substituents on the dihydrooxazole ring are hydrogen), R6 is 4-CF3- (while other substituents on the pyridine ring are hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 40° C., 480 g of 1,3-butadiene was added, and a constant pressure (2.7 bar) atmosphere was maintained, and diisobutylaluminum chloride (0.791 mol) was injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature was 40° C., and the polymerization reaction time was 4.7 h;

[0164] The temperature of the mixed system was controlled at 45°C, and ethylene monomer was introduced to maintain a constant pressure (35 bar) atmosphere, and then methylaluminoxane (MAO) (1.131 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization reaction temperature was 45°C, and the copolymerization reaction time was 36 min. The introduction of ethylene monomer was stopped;

[0165] The polymerization product was post-treated according to the method of Example 1 to obtain 509.0 g of ethylene-butadiene polymer.

[0166] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1646, 738 characteristic peaks of cis-1,4-butadiene rubber, 721 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 for cis-1,4-butadiene rubber peak, 1.10 for ethylene segment peak); polyethylene segment content is 17.1wt%, cis-1,4-butadiene rubber segment content is 82.9wt%; in cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 94.5mol%;

[0167] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 352,000 and the molecular weight distribution is 3.63.

[0168] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 4.0 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 90.9 wt %.

[0169] Embodiment 14

[0170] (1) After the polymerization reaction equipment was circulated three times using the double-row pipe operation technology, 2 L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH3- (other substituents on the benzene ring are hydrogen), R2 is H (all substituents on the pyridine ring are hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 45° C., 520 g of 1,3-butadiene was added, and a constant pressure (2.7 bar) atmosphere was maintained, and diisobutylaluminum chloride (1.357 mol) was injected to initiate the polymerization reaction of butadiene, and the polymerization reaction temperature was 45° C. and the polymerization reaction time was 4.7 h;

[0171] The temperature of the mixed system was controlled at 38°C, and ethylene monomer was introduced to maintain a constant pressure (42 bar) atmosphere, and then methylaluminoxane (MAO) (1.131 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 38°C, and the copolymerization time was 60 min, after which the introduction of ethylene monomer was stopped;

[0172] The polymerization product was post-treated according to the method of Example 1 to obtain 594.0 g of ethylene-butadiene polymer.

[0173] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1647, 738 characteristic peaks of cis-1,4-butadiene rubber, 721 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 20.4wt%, cis-1,4-butadiene rubber segment content is 79.6wt%; in cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 94.2mol%;

[0174] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 416,000 and the molecular weight distribution is 3.75.

[0175] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 5.3 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 89.6 wt %.

[0176] Embodiment 15

[0177] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 2 L of toluene and a catalyst as shown in Formula 1 (wherein R1 is 2,6-CH2CH3- (other substituents on the benzene ring are hydrogen), R2 is H (all substituents on the pyridine ring are hydrogen), and X is bromine) (2.260 mmol) were added, and the mixed system was dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 43° C., 480 g of 1,3-butadiene was added, and a constant pressure (2.7 bar) atmosphere was maintained, and diisobutylaluminum chloride (1.131 mol) was injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature was 43° C., and the polymerization reaction time was 3.9 h;

[0178] The temperature of the mixed system was controlled at 45°C, and ethylene monomer was introduced to maintain a constant pressure (18 bar) atmosphere, and then sesquiethylaluminum (0.452 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 45°C, and the copolymerization reaction time was 32 min, and then the introduction of ethylene monomer was stopped;

[0179] The polymerization product was post-treated according to the method of Example 1 to obtain 440.8 g of ethylene-butadiene polymer.

[0180] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1647, 741 characteristic peaks of cis-1,4-butadiene rubber, 722 wavenumber of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 8.8wt%, cis-1,4-butadiene rubber segment content is 91.2wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 96.3mol%;

[0181] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 312,000 and the molecular weight distribution is 3.19.

[0182] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 1.6 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 92.6 wt %.

[0183] Comparative Example 1

[0184] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2L of toluene and the catalyst shown in Formula 1 (wherein, R1=2,4,6-CH3- (other substituents on the benzene ring are hydrogen), R2 is H (the substituents on the pyridine ring are all hydrogen), and X is bromine) (2.260mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 55°C, 420g of 1,3-butadiene is added, and a constant pressure (3bar) atmosphere is maintained, and diisobutylaluminum chloride (1.584mol) is injected to initiate polymerization of butadiene monomers, and the reaction time is 4h;

[0185] The polymerization product was post-treated according to the method of Example 1 to obtain 381.4 g of butadiene rubber.

[0186] (2) Characterization of the obtained butadiene rubber: FT-IR (KBr, cm -1 ), (characteristic peaks of cis-1,4-butadiene rubber with wave numbers of 1644 and 739); H-NMR spectrum (ppm) (cis-1,4-butadiene rubber peak with chemical shift of 5.4); the content of cis-1,4-butadiene rubber segment is 100wt%; the content of cis-1,4-structure is 98.2mol%.

[0187] According to GPC test data, the number average molecular weight of the butadiene rubber is 147,000 and the molecular weight distribution is 2.68.

[0188] No toluene insoluble matter.

[0189] Comparative Example 2

[0190] The cis-1,4-butadiene rubber and polyethylene prepared in Comparative Example 1 were solution blended to prepare 124.6 g of a blend of polyethylene and cis-1,4-butadiene rubber, wherein the content of polyethylene was 7.3 wt % based on the total weight of the blend.

[0191] Toluene insoluble matter test data, the toluene insoluble matter content in the blend is 7.3wt%, based on the total weight of the toluene insoluble matter, the polyethylene segment content is 100wt%.

[0192] Comparative Example 3

[0193] The cis-1,4-butadiene rubber and polyethylene prepared in Comparative Example 1 were solution blended to prepare 100.6 g of a blend of polyethylene and cis-1,4-butadiene rubber, wherein the content of polyethylene was 10.3 wt % based on the total weight of the blend.

[0194] Toluene insoluble matter test data, the toluene insoluble matter content in the blend is 10.3wt%, based on the total weight of the toluene insoluble matter, the polyethylene segment content is 100wt%.

[0195] Comparative Example 4

[0196] (1) After the polymerization reaction equipment is circulated three times using the double-row pipe operation technology, 2L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH2CH3- (other substitution positions on the benzene ring are hydrogen), R2 is 4-CH3- (while other substitution positions on the pyridine ring are hydrogen), and X is bromine) (2.260mmol) are added, and the mixed system is dispersed uniformly by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 52°C, 200g of 1,3-butadiene is added, and a constant pressure (4bar) atmosphere is maintained, and diisobutylaluminum chloride (1.131mol) is injected to initiate a butadiene polymerization reaction, and the polymerization reaction temperature is 43°C, and the polymerization reaction time is 4h;

[0197] The temperature of the mixed system was controlled at 40°C, and ethylene monomer was introduced to maintain a constant pressure (20 bar) atmosphere, and then methylaluminoxane (MAO) (1.131 mol) was added to initiate copolymerization of ethylene and polybutadiene. The copolymerization temperature was 40°C, and the copolymerization time was 30 min, after which the introduction of ethylene monomer was stopped;

[0198] The polymerization product was post-treated according to the method of Example 1 to obtain 355.5 g of ethylene-butadiene polymer.

[0199] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1649, 741 characteristic peaks of cis-1,4-butadiene rubber, 721 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 for cis-1,4-butadiene rubber peak, 1.10 for ethylene segment peak); polyethylene segment content is 44.3wt%, cis-1,4-butadiene rubber segment content is 55.7wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 91.8mol%;

[0200] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 228,000 and the molecular weight distribution is 5.24.

[0201] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 10 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 84.2 wt %.

[0202] Comparative Example 5

[0203] (1) The polymerization reaction equipment was operated by double-row pipes for three cycles, and then 2 L of toluene and a catalyst as shown in Formula 1 (wherein R1 is 2,6-CH(CH3)2- (other substitution positions on the benzene ring are hydrogen), R2 is H (the substitution positions on the pyridine ring are all hydrogen), and X is chlorine) (2.260 mmol) were added. The mixed system was uniformly dispersed by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 45° C., diisobutylaluminum chloride (0.679 mol) and methylaluminoxane (MAO) (0.679 mol) were injected, 300 g of 1,3-butadiene was added, and ethylene monomer was introduced to maintain a constant pressure (10 bar). The polymerization temperature was 40° C. After polymerization for 10 min, the introduction of ethylene monomer was stopped, and the reaction time was 3 hours.

[0204] The polymerization product was post-treated according to the method of Example 1 to obtain 268.4 g of ethylene-butadiene polymer.

[0205] (2) Characterization of the obtained ethylene-butadiene polymer: FT-IR (KBr, cm -1 )(1650, 736 characteristic peaks of cis-1,4-butadiene rubber, 720 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 cis-1,4-butadiene rubber peak, 1.10 ethylene segment peak); polyethylene segment content is 6.7wt%, cis-1,4-butadiene rubber segment content is 93.3wt%; in the cis-1,4-butadiene rubber segment, the content of cis-1,4-structure is 85.8mol%;

[0206] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 68,000 and the molecular weight distribution is 3.22.

[0207] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 0.2 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 93.2 wt %.

[0208] Comparative Example 6

[0209] 200 g of the ethylene-butadiene polymer obtained in Example 6 was added with about 2 L of toluene and stirred at room temperature for 48 hours until no obvious solids were found. The filtrate was filtered through a stainless steel mesh with a pore size of 125 μm, and the filtrate was washed with methanol three times and vacuum dried to obtain 184.7 g of ethylene-butadiene polymer D6.

[0210] The obtained ethylene-butadiene polymer was characterized by FT-IR (KBr, cm -1)(1650, 736 characteristic peaks of cis-1,4-butadiene rubber, 720 wave number of polyethylene segment); H-NMR spectrum (ppm) (chemical shift of 5.4 for cis-1,4-butadiene rubber peak, 1.10 for ethylene segment peak); the content of polyethylene segment is 21.1wt%, the content of cis-1,4-butadiene rubber segment is 78.9wt%; the content of cis-1,4-structure in cis-1,4-butadiene rubber segment is 93.7mol%;

[0211] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 282,000 and the molecular weight distribution is 3.89.

[0212] No toluene insoluble matter.

[0213] Comparative Example 7

[0214] 300 mL of a toluene solution containing 13.5 g (0.25 mol) of 1,3-butadiene was added to a fully dried 400 mL pressure-resistant glass reactor, and then ethylene was introduced therein at 0.4 MPa. At the same time, in a glove box protected by a nitrogen atmosphere, 18.0 μmol of bis(2-phenylindenyl) gadolinium bis(dimethylsilylamide) [(2-PhC9H6)2GdN(SiHMe2)2], 36.0 μmol of dimethylaniline tetrakis(pentafluorophenyl)borate (Me2NHPhB(C6F5)4) and 0.90 mmol of diisobutylaluminum hydride were taken out from a glass container and dissolved in 10 mL of toluene to obtain a catalyst solution. The catalyst solution was then taken out from the glove box, and the catalyst solution converted to 17.5 μmol of gadolinium was added to the monomer solution, which was then polymerized at room temperature for 180 minutes. After the polymerization, the polymerization product was post-treated according to the method of Example 1 to obtain 11.7 g of copolymer D7.

[0215] The obtained ethylene-butadiene polymer was characterized by FT-IR (KBr, cm -1 )(characteristic peaks of butadiene rubber with wave numbers of 1650 and 736, and polyethylene segment with wave number of 720); H-NMR spectrum (ppm) (chemical shift of butadiene rubber peak is 5.4, and ethylene segment peak is 1.10); the content of polyethylene segment is 11.2wt%, and the content of butadiene rubber segment is 88.8wt%; in the butadiene rubber segment, the content of cis-1,4-structure is 97.7mol%.

[0216] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 177,000 and the molecular weight distribution is 1.93.

[0217] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-butadiene polymer is 0.1 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 83.4 wt %.

[0218] It can be seen from the examples and comparative examples that as the content of the ethylene segment in the polymer increases, the cis-1,4-structure content of the butadiene segment decreases slightly but remains above 92%, the molecular weight is between 80,000 and 500,000, and the molecular weight distribution shows a broadening trend but remains within 4.5. In Examples 1-15, the polymers are prepared by in-situ polymerization, and the content of toluene insolubles in the prepared polymers is 0.3-9wt%.

[0219] Comparative Example 1 is cis-1,4 polybutadiene without polyethylene segments. Comparative Examples 2-3 are blends of polyethylene and butadiene rubber with the same ethylene content as Examples 1 and 4. In Comparative Example 4, the ethylene segment structure content exceeds 40%, the cis-1,4-structure content of the butadiene segment is reduced to less than 92% and the polymer distribution is further widened to 5.24. In Comparative Example 5, by adding ethylene and butadiene monomers together, the cis-1,4-structure content of the obtained polymer is further reduced to 85.8% and the molecular weight is reduced.

[0220] Comparative Example 1 has no toluene insoluble matter, Comparative Examples 2-3 use physical mixing to add toluene insoluble polyethylene, the polymer of Comparative Example 4 has a high toluene insoluble matter content, and the polymer of Comparative Example 5 has a low toluene insoluble matter content; in Comparative Example 6, after filtering through a stainless steel mesh, the polyethylene segment content of the polymer decreases compared to Example 6, and there is no toluene insoluble matter. The toluene insoluble matter content of the polymer in Comparative Example 7 is low.

[0221] Test Case

[0222] Mixing and vulcanization: The ethylene-butadiene polymer prepared in Example 1, and the cis-1,2-butadiene rubber, and the blend of polyethylene and cis-1,2-butadiene rubber prepared in the comparative example were prepared into vulcanized rubber samples by the following methods:

[0223] Mixing process: All vulcanized rubber formulations were mixed in a HaproRM-200A torque rheometer (Harbin Hapro Electrical Technology Co., Ltd.), and the mixed samples were thinned 20 times on a two-roll mill to obtain the final mixed rubber. The mixing process is shown in Table 1.

[0224] Preparation of vulcanized rubber samples: After the obtained mixed rubber was allowed to stand at room temperature for 24 hours, it was placed in a processing template and vulcanized in an XLB-D350×350 flat plate vulcanizer with the vulcanization temperature set at 150°C and t90 as the vulcanization time.

[0225] Table 1

[0226] Adding time (min) Additives and fillers (parts by weight) 0-1 Polymer, 100 parts 1-2 ZnO, 4 parts; stearic acid, 1.5 parts 2-3 4010NA, 1 piece 3-6 N330, 45 copies 6-7 CZ, 1 part; D, 0.5 part 7-13 Mixing 13-14 Sulfur S, 1.5 parts 14-15 Finish

[0227] The tensile strength and tear strength of the prepared vulcanized rubber samples were measured, wherein the tensile strength was measured according to the standard GB / T 528-1998, and the tear strength was measured according to the standard GB / T529-1999. The results are shown in Table 2.

[0228] Table 2

[0229]

[0230]

[0231] It can be seen from the results of Table 2 and the comparison with the comparative examples that the polyethylene-enhanced cis-1,2-butadiene rubber prepared by the one-step polymerization method of the present invention in Examples 1-15 has a higher fracture strength and tear strength of the vulcanized rubber of the polymer, showing a better enhancement effect. With the increase of polyethylene content, the fracture strength and tear strength of the vulcanized rubber are on an upward trend. Relative to Comparative Examples 2-3, the fracture strength and tear strength of the polymer with the same ethylene content are also higher. At the same time, with the increase of the number average molecular weight, the fracture strength and tear strength of the vulcanized rubber are also on an upward trend. In Comparative Example 4, the ethylene segment content is further improved, and the tear strength maintains a higher strength, but the fracture strength is reduced. Due to the low molecular weight of the polymer obtained in Comparative Example 5, the fracture strength and tear strength of the vulcanized rubber are not high. In Comparative Example 6, after the toluene insoluble matter removal process, the mechanical properties of the obtained polymer vulcanized rubber decrease, which is lower than Example 6 and Example 11 with a lower polyethylene segment content, indicating that the toluene insoluble matter has a better reinforcement effect in the vulcanized rubber, and the fracture strength and tear strength of the vulcanized rubber can be improved. In Comparative Example 7, although the content of polyethylene segments in the ethylene-butadiene polymer is comparable to that in Example 11 and higher than that in Example 15 and Example 4, the content of toluene insoluble matter in Comparative Example 7 is relatively low, resulting in the breaking strength and tear strength of the vulcanized rubber being lower than those in Examples 4, 11 and 15.

[0232] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An ethylene-butadiene polymer, characterized in that The ethylene-butadiene polymer comprises a polyethylene segment and a butadiene rubber segment; based on the total weight of the ethylene-butadiene polymer, the content of the polyethylene segment is 0.1-40wt%, and the content of the butadiene rubber segment is 60-99.9wt%; in the butadiene rubber segment, based on the total molar amount of the butadiene rubber segment, the content of cis-1,4-structure is 90-98.5mol%; based on the total weight of the ethylene-butadiene polymer, the content of toluene insoluble matter is 0.2-10wt%.

2. The ethylene-butadiene polymer according to claim 1, wherein Based on the total weight of the ethylene-butadiene polymer, the content of the polyethylene segment is 1-35wt%, and the content of the butadiene rubber segment is 65-99wt%.

3. The ethylene-butadiene polymer according to claim 1 or 2, wherein In the butadiene rubber segment, based on the total molar amount of the butadiene rubber segment, the content of cis-1,4-structure is 92-98 mol%.

4. The ethylene-butadiene polymer according to any one of claims 1 to 3, wherein The number average molecular weight of the ethylene-butadiene polymer is 50,000-700,000, preferably 80,000-500,000; Preferably, the molecular weight distribution of the ethylene-butadiene polymer is 2-5, preferably 2.5-4.

5.

5. The ethylene-butadiene polymer according to any one of claims 1 to 4, wherein Based on the total weight of the ethylene-butadiene polymer, the content of toluene insoluble matter is 0.3-9wt%; Preferably, the content of the polyethylene segment is 85-95 wt % based on the total amount of the toluene insoluble matter.

6. A method for preparing an ethylene-butadiene polymer, characterized in that: The method comprises the following steps: (1) in the presence of an organic solvent and a catalyst, initiating a polymerization reaction of butadiene monomer using an aluminum-containing cocatalyst-1 to obtain a polybutadiene product; (2) adding the aluminum-containing co-catalyst-2 to the polymerization system obtained in step (1), and then introducing ethylene monomer to carry out copolymerization reaction with the polybutadiene active chain segment in the polybutadiene product to obtain the ethylene-butadiene polymer.

7. The method according to claim 6, wherein: In step (1), the catalyst is a cobalt-containing organic compound; Preferably, the catalyst is selected from at least one of the compound represented by Formula 1, the compound represented by Formula 2 and the compound represented by Formula 3: Wherein, X is chlorine or bromine; R1 is H, or a monosubstituted substituent at position 2 or 4 on the benzene ring, or the same or different substituents at positions 2, 4 or 2, 6 on the benzene ring, or the same or different substituents at positions 2, 4, and 6 on the benzene ring, and the substituent is -F, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2; R3 is H, or -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2 which are monosubstituted at the 6-position of the pyridine ring, or -CH3, -N(CH3)2 or -CF3 which are monosubstituted at the 4-position of the pyridine ring, or -CH3, -CH2CH3, -C6H5, -CH(C6H5)2, -N(CH3)2 or -CF3 which are disubstituted at the 4- and 6-positions of the pyridine ring, which are the same or different; R5 is H, or -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5 or -CH(C6H5)2 which is monosubstituted at the 4-position of the dihydrooxazole ring; R2, R4, and R6 are each independently hydrogen, or -Cl, -F, -CH3, -OCH3, -N(CH3)2, or -CF3 which is monosubstituted at the 4-position of the pyridine ring.

8. The method according to claim 6 or 7, wherein: The catalyst: the molar ratio of the aluminum-containing co-catalyst-1 to the aluminum-containing co-catalyst-2 is 1:20-1000:15-1000, preferably 1:40-900:20-900; Preferably, relative to 1 mol of butadiene, the amount of the catalyst is 0.1-1.6 mmol, preferably 0.15-1.2 mmol; Preferably, the organic solvent is selected from at least one of n-pentane, neopentane, n-hexane, cyclohexane, n-heptane, n-octane, isooctane, benzene, toluene, decahydronaphthalene, dodecane and hydrogenated gasoline, preferably toluene.

9. The method according to any one of claims 6 to 8, wherein: The polymerization reaction conditions include: polymerization reaction temperature of 30-70°C, preferably 40-60°C; polymerization reaction pressure of 1-10 bar, preferably 2-5 bar; polymerization reaction time of 1-6h, preferably 2-5h; Preferably, the copolymerization reaction conditions include: copolymerization reaction temperature of 20-70°C, preferably 30-60°C; copolymerization reaction pressure of 1-70 bar, preferably 5-50 bar; copolymerization reaction time of 1-80 min, preferably 5-60 min.

10. The method according to any one of claims 6 to 9, wherein: The aluminum-containing co-catalyst-1 is selected from at least one of diethylaluminum chloride, ethylaluminum sesquichloride, di-n-propylaluminum chloride, diisopropylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, di-n-octylaluminum chloride, ethylaluminum dichloride, n-propylaluminum dichloride, isopropylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride, n-octylaluminum dichloride, methylaluminoxane and methylaluminoxane modified with triisobutylaluminum, preferably at least one of diisobutylaluminum chloride, diethylaluminum chloride, ethylaluminum sesquichloride and methylaluminoxane.

11. The method according to any one of claims 6 to 10, wherein: The aluminum-containing co-catalyst-2 is selected from at least one of methylaluminoxane, methylaluminoxane modified with triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, di-n-propylaluminum chloride, diisopropylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, di-n-octylaluminum chloride, ethylaluminum dichloride, n-propylaluminum dichloride, isopropylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride and n-octylaluminum dichloride, preferably at least one of methylaluminoxane, methylaluminoxane modified with triisobutylaluminum, diisobutylaluminum chloride, diethylaluminum chloride and ethylaluminum sesquichloride.

12. An ethylene-butadiene polymer obtained by the process according to any one of claims 6 to 11.

13. A vulcanized rubber obtained from a composition comprising the ethylene-butadiene polymer according to any one of claims 1 to 5 and 12.

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