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 polybutadiene 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 polybutadiene chain segment is 60-99.9 wt%; in the polybutadiene chain segment, based on the total molar weight of the polybutadiene chain segment, the content of a 1, 2-structure is 60-90 mol%. An ethylene structure chain segment is introduced into a butadiene structure chain segment of the high-vinyl polybutadiene rubber, so that the high-vinyl polybutadiene rubber is modified, and the mechanical property is remarkably improved.

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] Ethylene is a widely used and readily available monomer in the plastics industry. Conjugated dienes, especially butadiene and isoprene, are the most important monomers for synthetic rubber. However, due to the different polymerization mechanisms of conjugated dienes and α-olefins, it is difficult to achieve copolymerization of the two. Therefore, using the same catalytic system to catalyze the copolymerization of ethylene and conjugated dienes is a very challenging topic, and achieving the copolymerization of the two has always been the direction of academic and industrial efforts.

[0003] The excellent tensile strength, tear strength, corrosion resistance, electrical insulation, anti-slip, low heat generation and aging resistance of polyethylene can be used to improve the anti-slip, tensile strength, tear resistance and wear resistance of cis-1,1-dione rubber products, thereby improving the use performance and service life of cis-1,1-dione rubber products. CN106117655A discloses a kind of anti-slip cis-1,1-dione rubber material, using the method of blending to physically mix high-density polyethylene, chlorosulfonated polyethylene, polyvinyl butyral, alkylphenol polyoxyethylene ether, polyvinyl alcohol and cis-1,1-dione rubber. However, polyethylene is plastic, and butadiene rubber is elastomer, and the difference in performance of the two materials causes pure mechanical mixing to have poor dispersibility, the difficulty of processing difficulty improvement, and its rubber product physical and chemical properties are also not as good as copolymerization products.

[0004] Therefore, providing a polyethylene butadiene rubber reinforcement with good dispersibility and a catalytic preparation technology thereof is a problem that needs to be solved at present. Summary of the invention

[0005] The purpose of the present invention is to improve the disadvantage of poor mechanical properties of existing high-vinyl polybutadiene rubber materials, and to provide an ethylene-butadiene polymer and a preparation method thereof and a vulcanized rubber. The ethylene-butadiene polymer comprises a polyethylene segment and a polybutadiene segment, and an ethylene structure segment is introduced into the butadiene structure segment of the high-vinyl polybutadiene rubber to achieve modification of the high-vinyl polybutadiene rubber, so that the mechanical properties of the ethylene-butadiene polymer are significantly improved.

[0006] 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 polybutadiene 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 polybutadiene segment is 60-99.9wt%; in the polybutadiene segment, based on the total amount of the polybutadiene segment, the content of 1,2-structure is 60-90mol%.

[0007] A second aspect of the present invention provides a method for preparing an ethylene-butadiene polymer, the preparation method comprising:

[0008] (1) in the presence of an organic solvent and a catalyst, using an aluminum-containing cocatalyst-1 to initiate a polymerization reaction of ethylene monomer to obtain a polyethylene product;

[0009] (2) adding the phosphine-containing additive 1 to the polyethylene product;

[0010] (3) adding an organic solution containing butadiene and an aluminum-containing co-catalyst-2 to the mixed system obtained in step (2) in sequence to initiate a copolymerization reaction between the butadiene monomer and the polyethylene active chain segment in the polyethylene product to obtain the ethylene-butadiene polymer.

[0011] The third aspect of the present invention provides an ethylene-butadiene polymer prepared by the preparation method of the present invention.

[0012] A fourth aspect of the present invention provides a vulcanized rubber, wherein the vulcanized rubber is prepared from a composition comprising the ethylene-butadiene polymer of the present invention.

[0013] 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:

[0014] The ethylene-butadiene polymer provided by the present invention comprises polyethylene segments and polybutadiene segments, and the polyethylene segments and polybutadiene segments are distributed in blocks; the polyethylene segments contained in the polymer can achieve modification of high-vinyl polybutadiene segments, and this chemical linking method effectively avoids the problems of phase separation, interface failure, etc. caused by direct blending of polyethylene and high-vinyl polybutadiene rubber in traditional processes, so that the vulcanized rubber prepared from the composition comprising the ethylene-butadiene polymer has improved mechanical properties.

[0015] In the preparation method of the 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 high-vinyl polybutadiene, and the polymer containing polyethylene segments and high-vinyl polybutadiene segments of the present invention is obtained by in-situ polymerization. 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. DETAILED DESCRIPTION

[0016] 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.

[0017] 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 polybutadiene 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 polybutadiene segment is 60-99.9wt%; in the polybutadiene segment, based on the total molar amount of the polybutadiene segment, the content of 1,2-structure is 60-90mol%.

[0018] In the present invention, the ethylene-butadiene polymer comprises polyethylene segments and polybutadiene segments, and the polyethylene segments and polybutadiene segments are distributed in blocks; the polyethylene segments contained in the polymer can achieve modification of high-vinyl polybutadiene segments, and the chemical bonding method avoids the problems of phase separation and interface failure caused by direct blending of polyethylene with high-vinyl polybutadiene rubber in the traditional process, so that the vulcanized rubber prepared from the composition comprising the ethylene-butadiene polymer has improved mechanical properties.

[0019] Furthermore, when the contents of the polyethylene segment and the polybutadiene segment in the ethylene-butadiene polymer and the content of the 1,2-structure in the polybutadiene segment meet the above ranges, the mechanical properties of the vulcanized rubber prepared from the composition containing the ethylene-butadiene polymer are further improved.

[0020] 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 1-30 wt %, and the content of the polybutadiene segment is 70-99 wt %.

[0021] In some preferred embodiments of the present invention, preferably, in the polybutadiene segment, based on the total molar amount of the polybutadiene segment, the content of 1,2-structure is 65-85 mol%.

[0022] In the present invention, the contents of polyethylene segments and polybutadiene segments in the ethylene-butadiene polymer, and the content of 1,2-structure in the polybutadiene segment are measured by hydrogen nuclear magnetic spectrum.

[0023] In some preferred embodiments of the present invention, the Tm of the ethylene-butadiene polymer is 120-150°C, preferably 125-145°C.

[0024] In some preferred embodiments of the present invention, the Tc of the ethylene-butadiene polymer is 100-125°C, preferably 105-121°C.

[0025] In some preferred embodiments of the present invention, the crystallinity of the ethylene-butadiene polymer is 0.2-30%, preferably 0.5-25%.

[0026] In the present invention, when at least one of Tm, Tc and crystallinity of the ethylene-butadiene polymer satisfies the above range, the comprehensive properties of the ethylene-butadiene polymer can be further improved, so that the mechanical properties of the vulcanized rubber prepared therefrom are improved.

[0027] In the present invention, Tm, Tc and crystallinity of the ethylene-butadiene polymer are measured by DSC.

[0028] In some preferred embodiments of the present invention, preferably, the number average molecular weight of the ethylene-butadiene polymer is 100,000-800,000, preferably 150,000-600,000.

[0029] In some preferred embodiments of the present invention, preferably, the molecular weight distribution of the ethylene-butadiene polymer is 2.5-6.5, preferably 3-5.

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

[0032] (1) in the presence of an organic solvent and a catalyst, using an aluminum-containing cocatalyst-1 to initiate a polymerization reaction of ethylene monomer to obtain a polyethylene product;

[0033] (2) adding a phosphine-containing additive 1 to the polyethylene product;

[0034] (3) adding an organic solution containing butadiene and an aluminum-containing co-catalyst-2 to the mixed system obtained in step (2) in sequence to initiate a copolymerization reaction between the butadiene monomer and the polyethylene active chain segment in the polyethylene product to obtain the ethylene-butadiene polymer.

[0035] In the preparation method of the 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 high-vinyl polybutadiene, and the polymer comprising polyethylene segments and high-vinyl polybutadiene segments of the present invention is obtained by in-situ polymerization. In the polymer, the polyethylene segments and the polybutadiene segments are bonded together by chemical bonds, so that the obtained ethylene-butadiene polymer has improved performance.

[0036] 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.

[0037] Specifically, by adopting the preparation method provided by the present invention, the ethylene-butadiene polymer comprising a specific content of polyethylene segments and polybutadiene segments as described in the first aspect of the present invention can be obtained, and the polybutadiene segments contain a specific content of 1,2-structure.

[0038] In a specific embodiment of the present invention, ethylene polymerization can be performed first, and then copolymerization of polyethylene and butadiene monomers can be performed. The two reaction processes can be performed continuously, and the same catalyst can be used in the polymerization reaction and the copolymerization reaction, and then different co-catalysts can be used to initiate different monomers, respectively, to achieve the reaction of different monomers to synthesize the corresponding segments.

[0039] In a specific embodiment of the present invention, preferably, the catalyst is a cobalt-based catalyst containing a cobalt organic compound.

[0040] In one embodiment of the present invention, preferably, in step (1), the catalyst is selected from the compound represented by formula 1 and / or the compound represented by formula 2:

[0041]

[0042] wherein X is chlorine or bromine; R1 is H, or a monosubstituted substituent at position 2 or 4 on the benzene ring, or a disubstituted substituent at positions 2, 4 or 2, 6 on the benzene ring that is the same or different, or a trisubstituted substituent at positions 2, 4, and 6 on the benzene ring that is the same or different, and the substituent is -F, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -C6H5, or -CH(C6H5)2;

[0043] R3 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;

[0044] R2 and R4 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.

[0045] 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, mono-substituted at position 2 or 4 on the benzene ring, or di-substituted at position 2, 4 or 2, 6 on the benzene ring, or tri-substituted at position 2, 4, 6 on the benzene ring, and the other substitution positions are H, wherein the substituents may be the same or different in the case of di- and tri-substitution, and preferably, -F, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, - C6H5 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.

[0046] In some embodiments of the present invention, R3 represents a substituent on the dihydrooxazole ring in Formula 3, and multiple substitution positions on the dihydrooxazole ring are allowed to be all H; or R3 represents that some of the substitution positions on the dihydrooxazole ring are substituent groups 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.

[0047] In some embodiments of the present invention, R2 and R4 each independently represent a substituent on the pyridine ring in formula 1 and 2, and multiple substitution positions on the pyridine ring substituted by R2 and R4 are all H, preferably R2 and R4 are H; or, R2 and R4 represent -Cl, -F, -CH3, -OCH3, -N(CH3)2 or -CF3 substituted at the 4th position 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-. R2 and R4 may be the same or different. 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 the 4th position on the pyridine ring.

[0048] In some embodiments of the present invention, the aluminum-containing cocatalyst-1 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-1, the polymerization reaction of the ethylene monomer is initiated.

[0049] In some embodiments of the present invention, preferably, in step (2), the phosphine-containing auxiliary agent 1 is selected from at least one of triphenylphosphine, tri(3-methylphenyl)phosphine, tri(3-methoxyphenyl)phosphine, isopropyldiphenylphosphine, isopropyldiphenylphosphine and tert-butyldiphenylphosphine, preferably selected from triphenylphosphine and / or isopropyldiphenylphosphine.

[0050] In some 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 and n-octylaluminum dichloride, preferably at least one of diisobutylaluminum chloride, diethylaluminum chloride and ethylaluminum sesquichloride. In the present invention, under the joint action of the catalyst, the phosphine-containing cocatalyst 1 and the aluminum-containing cocatalyst-2, the copolymerization reaction of butadiene monomer and polyethylene active chain segment is initiated.

[0051] 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 1:15-1000:20-1000.

[0052] In some embodiments of the present invention, preferably, the molar ratio of the catalyst to the phosphine-containing auxiliary agent 1 is 1:0.5-2.

[0053] In the present invention, when the molar ratio of the catalyst, the aluminum-containing co-catalyst-1 to the aluminum-containing co-catalyst-2, and the molar ratio of the catalyst to the phosphine-containing auxiliary agent 1 are controlled to meet the above ranges, the reaction activities of the polymerization reaction and the copolymerization reaction in step (1) and step (3) can be controlled, thereby achieving control of the content of the polyethylene segment and the polybutadiene segment in the ethylene-butadiene polymer, and the content of the 1,2-structure in the polybutadiene segment.

[0054] In a preferred embodiment 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 1:20-900:40-900.

[0055] In a preferred embodiment of the present invention, preferably, the molar ratio of the catalyst to the phosphine-containing auxiliary agent 1 is 1:0.8-1.5.

[0056] In some embodiments of the present invention, preferably, the amount of the catalyst is 0.3-16mmoL, preferably 0.4-12mmoL, relative to 1moL ethylene. In the present invention, controlling the amount of the catalyst to meet the above range has the effect of ensuring the ethylene polymerization activity and regulating the content of the polyethylene segment of the polymer.

[0057] In some embodiments of the present invention, preferably, in step (1), the polymerization temperature is 20-70°C, preferably 30-60°C; the polymerization pressure is 1-70 bar, preferably 2.5-50 bar; the polymerization time is 1-80 min, preferably 2-60 min. In the present invention, the polymerization pressure in step (1) can be the gas phase pressure of the ethylene monomer.

[0058] In some embodiments of the present invention, preferably, in step (3), the concentration of the butadiene-containing organic solution is 0.4-12 mol / L, preferably 0.6-9 mol / L. In the present invention, there is no particular limitation on the amount of the organic solvent, as long as the concentration of the butadiene-containing organic solvent in step (3) satisfies the above range.

[0059] In some embodiments of the present invention, the organic solvent in step (1) and step (3) is the same. 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.

[0060] In some embodiments of the present invention, preferably, in step (3), the copolymerization reaction temperature is 30-70°C, preferably 40-60°C; the copolymerization reaction pressure is 1-10 bar, preferably 2-5 bar; the copolymerization reaction time is 2-7h, preferably 3-6h. In the present invention, the copolymerization reaction pressure of step (3) can be the gas phase pressure of the fed butadiene monomer.

[0061] In some embodiments of the present invention, the amount relationship of ethylene and butadiene can be controlled by the time and pressure of the ethylene monomer into the reaction, thereby obtaining the ethylene-butadiene polymer of the present invention, that is, a polymer with a high vinyl polybutadiene segment as an elastic phase and a polyethylene segment as a reinforcing phase. Preferably, the feed weight relationship of the ethylene monomer and the butadiene monomer satisfies the amount of the corresponding polyethylene segment and the polybutadiene 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 1-30wt%; the content of the polybutadiene segment is 60-99.9wt%, preferably 70-99wt%; in the polybutadiene segment, based on the total molar amount of the polybutadiene segment, the content of 1,2-structure is 60-90mol%, preferably 65-85mol%.

[0062] In the present invention, when the copolymerization reaction needs to be terminated, the following steps may also be included:

[0063] 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-butadiene polymer.

[0064] In the present invention, the stabilizer can be a reagent that has an antioxidant effect, and can be a toluene solution of 2,2-methylenebis-(4-methyl-6-tert-butylphenol) with a mass concentration of 5%, and can be added in an amount of 0.5wt%-1wt% of the total weight of the monomer. The terminator can be a reagent that terminates polymerization and removes residual catalysts, and can be a methanol solution of hydrochloric acid with a mass concentration of 4%, and can be added in an amount of 0.1wt%-1wt% of the total weight of the monomer. The washing process can be using methanol solution and water in sequence for about 3 times.

[0065] In one specific embodiment of the present invention, the method for preparing the ethylene-butadiene polymer comprises the following steps:

[0066] The reaction equipment is operated with double-row pipes to purify the polymerization reaction environment; 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 ethylene monomer is introduced into the reaction equipment at a pressure of 1-70 bar, and after maintaining a constant pressure, a set amount of aluminum-containing cocatalyst-1 is added to initiate ethylene polymerization reaction, and the polymerization reaction time is determined according to the different content of polyethylene segments in the finally obtained ethylene butadiene polymer;

[0067] After reaching the set polymerization reaction time, stop introducing ethylene monomer, add phosphine-containing auxiliary agent 1, and then add purified butadiene monomer, remove residual ethylene monomer and reduce the pressure to 1-10 bar; add aluminum-containing co-catalyst-2 to initiate copolymerization of butadiene monomer and polyethylene active chain segment, and maintain constant pressure for the set time;

[0068] 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 ethylene-butadiene polymer.

[0069] The third aspect of the present invention provides an ethylene-butadiene polymer prepared by the preparation method of the present invention.

[0070] 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.

[0071] A fourth aspect of the present invention provides a vulcanized rubber, wherein the vulcanized rubber is prepared from a composition comprising the ethylene-butadiene polymer of the present invention.

[0072] The present invention will be described in detail below by way of examples. In the following examples,

[0073] The content of polyethylene segments in ethylene-butadiene polymers, the content of polybutadiene segments and the content of 1,2-structure in polybutadiene segments were measured by hydrogen nuclear magnetic spectroscopy.

[0074] The number average molecular weight and molecular weight distribution of ethylene-butadiene polymers were measured by GPC.

[0075] The Tm, Tc and crystallinity of ethylene-butadiene polymers were measured by DSC.

[0076] The raw materials used in the examples and comparative examples are all commercially available.

[0077] Example 1

[0078] (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-diisopropyl, R2 is H, and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 30° C., ethylene monomer was introduced to maintain a constant pressure (4 bar) atmosphere, and then methylaluminoxane (MAO) (0.679 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after 5 minutes of polymerization; triphenylphosphine (2.260 mmol) was added to the obtained polyethylene product.

[0079] Nitrogen was introduced into the polymerization device to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 247 g of 1,3-butadiene was added, and a constant pressure (3 bar) atmosphere was maintained. Diisobutylaluminum chloride (0.679 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 45° C. and the copolymerization reaction time was 4 h.

[0080] 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 for 3 times and vacuum dried to obtain 242.7 g of ethylene-butadiene polymer A1.

[0081] (2) The obtained ethylene-butadiene polymer was characterized: H NMR spectrum (ppm) (chemical shifts were 5.4 and 5 for the polybutadiene segment peaks, 1.10 for the polyethylene segment peak); the polyethylene segment content was 4.2 wt%, the polybutadiene segment content was 95.8 wt%; in the polybutadiene segment, the 1,2-structure content was 83.9 mol%;

[0082] DSC test data, the melting temperature of the ethylene-butadiene polymer is Tm = 131.2 ° C, the crystallization temperature is Tc = 113.6 ° C, and the crystallinity is 2.8%;

[0083] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 163,000 and the molecular weight distribution is 3.16.

[0084] Example 2

[0085] (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-diisopropyl, R2 is 4-OCH3-, and X is bromine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 39° C., ethylene monomer was introduced while maintaining a constant pressure (4.9 bar) atmosphere, and then methylaluminoxane (MAO) (1.36 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after 2 minutes of polymerization; triphenylphosphine (2.03 mmol) was added to the obtained polyethylene product.

[0086] Nitrogen was introduced into the polymerization equipment to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 463 g of 1,3-butadiene was added, and a constant pressure (2 bar) atmosphere was maintained. Diisobutylaluminum chloride (0.679 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 48° C. and the copolymerization reaction time was 3.5 h.

[0087] The polymerization product was post-treated according to the method of Example 1 to obtain 2452.4 g of ethylene-butadiene polymer A.

[0088] (2) The obtained ethylene-butadiene polymer was characterized by: H-NMR spectrum (ppm) (chemical shifts were 5.4 and 5 for the polybutadiene segment peaks, 1.10 for the polyethylene segment peak); the polyethylene segment content was 1.6 wt%, the polybutadiene segment content was 98.4 wt%; in the polybutadiene segment, the 1,2-structure content was 84.8 mol%;

[0089] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 129.3°C, the crystallization temperature is Tc = 110.2°C, and the crystallinity is 0.9%;

[0090] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 334,000 and the molecular weight distribution is 3.02.

[0091] Example 3

[0092] (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 1 (wherein R1 is 2,4,6-trimethyl, R2 is 4-fluoro, and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 35° C., ethylene monomer was introduced to maintain a constant pressure (8 bar) atmosphere, and then diethylaluminum chloride (0.113 mol) was added to initiate ethylene polymerization. The polymerization reaction time was 18 min, and then the introduction of ethylene monomer was stopped; triphenylphosphine (3.16 mmol) was added to the obtained polyethylene product.

[0093] Nitrogen was introduced into the polymerization device to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 578 g of 1,3-butadiene was added, and a constant pressure (4 bar) atmosphere was maintained. Diisobutylaluminum chloride (0.679 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 50° C. and the copolymerization reaction time was 4.5 h.

[0094] The polymerization product was post-treated according to the method of Example 1 to obtain 3572.3 g of ethylene-butadiene polymer A.

[0095] (2) The obtained ethylene-butadiene polymer was characterized by: H-NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for ethylene segment peaks); the polyethylene segment content was 17.8 wt %, the polybutadiene segment content was 82.2 wt %; in the polybutadiene segment, the 1,2-structure content was 76.3 mol %;

[0096] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 135.2°C; the crystallization temperature is Tc = 117.3°C, and the crystallinity is 12.2%.

[0097] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 309,000 and the molecular weight distribution is 4.24.

[0098] Example 4

[0099] (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-diethyl, R2 is 4-N(CH3)2, and X is bromine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 33° C., ethylene monomer was introduced to maintain a constant pressure (5 bar) atmosphere, and then modified methylaluminoxane (MMAO) (1.584 mol) was added to initiate ethylene polymerization, and the reaction time was 10 min; the introduction of ethylene monomer was stopped; and tri(3-methylphenyl)phosphine (2.26 mmol) was added to the obtained polyethylene product.

[0100] Nitrogen was introduced into the polymerization equipment to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 297 g of 1,3-butadiene was added, and a constant pressure (3 bar) atmosphere was maintained. Diisobutylaluminum chloride (1.584 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 53° C. and the copolymerization reaction time was 5 h.

[0101] The polymerization product was post-treated according to the method of Example 1 to obtain 4293.8 g of ethylene-butadiene polymer A.

[0102] (2) The obtained ethylene-butadiene polymer was characterized by: H NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for ethylene segment peaks); the polyethylene segment content was 15.2 wt%, the polybutadiene segment content was 84.8 wt%; in the polybutadiene segment, the 1,2-structure content was 79.6 mol%;

[0103] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 134.7°C; the crystallization temperature is Tc = 114.8°C, and the crystallinity is 9.8%.

[0104] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 162,000 and the molecular weight distribution is 3.92.

[0105] Example 5

[0106] (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-C(CH3)3-6-CH3, R2 is 4-Cl, and X is bromine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 37° C., ethylene monomer was introduced to maintain a constant pressure (5 bar) atmosphere, and then diethylaluminum chloride (45.2 mmol) was added to initiate ethylene polymerization, and the reaction time was 27 min; then the introduction of ethylene monomer was stopped; and tri(3-methylphenyl)phosphine (2.01 mmol) was added to the obtained polyethylene product.

[0107] Nitrogen was introduced into the polymerization equipment to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 487 g of 1,3-butadiene was added, and a constant pressure (2.2 bar) atmosphere was maintained. Diisobutylaluminum chloride (2.036 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 54° C. and the copolymerization reaction time was 5 h.

[0108] The polymerization product was post-treated according to the method of Example 1 to obtain ethylene-butadiene polymer A5

[0109] 482.3g.

[0110] (2) The obtained ethylene-butadiene polymer was characterized by: H-NMR spectrum (ppm) (chemical shifts were 5.4 and 5 for polybutadiene peaks, 1.10 for ethylene segment peak); the polyethylene segment content was 6.8 wt%, the polybutadiene segment content was 93.2 wt%; in the polybutadiene segment, the 1,2-structure content was 83.1 mol%;

[0111] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 132.2°C; the crystallization temperature is Tc = 112.6°C, and the crystallinity is 4.2%.

[0112] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 305,000 and the molecular weight distribution is 3.25.

[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-isopropyl, R4 is 4-methoxy, and X is bromine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 50° C., ethylene monomer was introduced to maintain a constant pressure (8 bar) atmosphere, and then diethylaluminum chloride (0.684 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after the reaction time was 32 min; tri(3-methylphenyl)phosphine (2.26 mmol) was added to the obtained polyethylene product.

[0115] Nitrogen was introduced into the polymerization equipment to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 423 g of 1,3-butadiene was added, and a constant pressure (3.5 bar) atmosphere was maintained. Diisobutylaluminum chloride (0.684 mol) was injected to initiate the copolymerization of butadiene monomer. The copolymerization temperature was 60° C. and the copolymerization time was 3.8 h.

[0116] The polymerization product was post-treated according to the method of Example 1 to obtain 6459.3 g of ethylene-butadiene polymer A.

[0117] (2) The obtained ethylene-butadiene polymer was characterized by: H-NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for ethylene segment peaks); the polyethylene segment content was 28.5 wt%, the polybutadiene segment content was 71.5 wt%; in the polybutadiene segment, the 1,2-structure content was 72.6 mol%;

[0118] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 137.1°C, the crystallization temperature is Tc = 116.8°C, and the crystallinity is 22.7%.

[0119] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 233,000 and the molecular weight distribution is 4.86.

[0120] Example 7

[0121] (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 2 (wherein R3 is 4-C6H5-, R4 is 4-CF3-, and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 45° C., ethylene monomer was introduced to maintain a constant pressure (8 bar) atmosphere, and then methylaluminoxane (MAO) (1.131 mol) was added to initiate ethylene polymerization, and the reaction time was 18 min; the introduction of ethylene monomer was stopped; and triphenylphosphine (2.71 mmol) was added to the obtained polyethylene product.

[0122] Nitrogen was introduced into the polymerization device to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 889 g of 1,3-butadiene was added, and a constant pressure (4.5 bar) atmosphere was maintained. Ethyl aluminum sesquihydrate (1.131 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 40° C. and the copolymerization reaction time was 4 h.

[0123] The polymerization product was post-treated according to the method of Example 1 to obtain 7827.9 g of ethylene-butadiene polymer A.

[0124] (2) The obtained ethylene-butadiene polymer was characterized: H NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for polyethylene segment peaks); the polyethylene segment content was 9.2 wt%, the polybutadiene segment content was 90.8 wt%; in the polybutadiene segment, the 1,2-structure content was 81.3 mol%;

[0125] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 132.1°C; the crystallization temperature is Tc = 111.9°C, and the crystallinity is 7.4%.

[0126] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 529,000 and the molecular weight distribution is 3.48.

[0127] Example 8

[0128] (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-dimethyl, R2 is H, and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 38° C., ethylene monomer was introduced to maintain a constant pressure (5.2 bar) atmosphere, and then methylaluminoxane (MAO) (1.584 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after the reaction time was 20 min; isopropyldiphenylphosphine (2.94 mmol) was added to the obtained polyethylene product.

[0129] Nitrogen was introduced into the polymerization equipment to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 464 g of 1,3-butadiene was added, and a constant pressure (2.8 bar) atmosphere was maintained. Diisobutylaluminum chloride (1.584 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 45° C. and the copolymerization reaction time was 5.5 h.

[0130] The polymerization product was post-treated according to the method of Example 1 to obtain 487.4 g of ethylene-butadiene polymer A8.

[0131] (2) The obtained ethylene-butadiene polymer was characterized: H-NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for polyethylene segment peaks); the polyethylene segment content was 24.7 wt%, the polybutadiene segment content was 75.3 wt%; in the polybutadiene segment, the 1,2-structure content was 68.7 mol%;

[0132] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 136.2°C; the crystallization temperature is Tc = 113.9°C, and the crystallinity is 20.3%.

[0133] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 255,000 and the molecular weight distribution is 4.55.

[0134] Example 9

[0135] (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-diisopropyl, R2 is hydrogen, and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 45° C., ethylene monomer was introduced to maintain a constant pressure (4 bar) atmosphere, and then methylaluminoxane (MAO) (2.034 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after the reaction time was 23 min; isopropyldiphenylphosphine (1.95 mmol) was added to the obtained polyethylene product.

[0136] Nitrogen was introduced into the polymerization device to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 382 g of 1,3-butadiene was added, and a constant pressure (4 bar) atmosphere was maintained. Diisobutylaluminum chloride (2.034 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 43° C. and the copolymerization reaction time was 3 h.

[0137] The polymerization product was post-treated according to the method of Example 1 to obtain 377.9 g of ethylene-butadiene polymer.

[0138] (2) The obtained polyethylene in-situ reinforced polybutadiene was characterized: H NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for ethylene segment peaks); the polyethylene segment content was 12.5wt%, the polybutadiene segment content was 87.5wt%; in the polybutadiene segment, the 1,2-structure content was 76.4mol%;

[0139] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 133.5°C, the crystallization temperature is Tc = 113.5°C, and the crystallinity is 9.4%.

[0140] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 217,000 and the molecular weight distribution is 3.66.

[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 2 (wherein R3 is 4-tert-butyl, R4 is H, 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 36° C., ethylene monomer was introduced to maintain a constant pressure (7 bar) atmosphere, and then diethylaluminum chloride (226 mmol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after the reaction time was 35 min; isopropyldiphenylphosphine (2.48 mmol) was added to the obtained polyethylene product.

[0143] Nitrogen was introduced into the polymerization equipment to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 453 g of 1,3-butadiene was added, and a constant pressure (3.3 bar) atmosphere was maintained. Diisobutylaluminum chloride (1.584 mol) was injected to initiate the butadiene copolymerization reaction. The copolymerization reaction temperature was 47° C. and the copolymerization reaction time was 5 h.

[0144] The polymerization product was post-treated according to the method of Example 1 to obtain 10457.1 g of ethylene-butadiene polymer A.

[0145] (2) The obtained ethylene-butadiene polymer was characterized by H NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene peaks, 1.10 for ethylene segment peaks); the polyethylene segment content was 20.7 wt%, the polybutadiene segment content was 79.3 wt%; in the polybutadiene segment, the 1,2-structure content was 70.4 mol%;

[0146] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 135.1°C, the crystallization temperature is Tc = 115.9°C, and the crystallinity is 16.9%.

[0147] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 240,000 and the molecular weight distribution is 4.40.

[0148] Comparative Example 1

[0149] (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-diisopropyl, R2 is H, and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer, and triphenylphosphine (2.26 mmol) was added; the evenly dispersed mixed system was heated to 70° C., 389 g of 1,3-butadiene was added, and a constant pressure (3 bar) atmosphere was maintained, and diisobutylaluminum chloride (1.584 mol) was injected to initiate polymerization of butadiene monomers, and the reaction time was 4 h;

[0150] The polymerization product was post-treated according to the method of Example 1 to obtain 385.6 g of high-ethylene polybutadiene rubber D1.

[0151] (2) Characterization of the obtained high-ethylene polybutadiene rubber: H-NMR spectrum (ppm) (polybutadiene segment peaks with chemical shifts of 5 and 5.4); polybutadiene segment content of 100 wt%; 1,2-structure content of 86.3 mol%. DSC test data showed no obvious melting peak or crystallization peak.

[0152] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 178,000 and the molecular weight distribution is 2.93.

[0153] Comparative Example 2

[0154] The high vinyl polybutadiene rubber D1 obtained in Comparative Example 1 and polyethylene were solution blended to prepare 82.6 g of a blend D2 of polyethylene and polybutadiene rubber, wherein the content of polyethylene was 6.8 wt % based on the total weight of the blend.

[0155] From the DSC test data, it can be seen that the melting temperature Tm of the blend is 135°C, the crystallization temperature Tc is 114.5°C, and the crystallinity is 4.8%.

[0156] Comparative Example 3

[0157] The high vinyl polybutadiene rubber and polyethylene prepared in Comparative Example 1 were solution blended to prepare 85.6 g of a blend D3 of polyethylene and polybutadiene rubber, wherein the content of polyethylene was 9.2 wt % based on the total weight of the blend.

[0158] From the DSC test data, it can be seen that the melting temperature Tm of the blend is 135.2°C, the crystallization temperature Tc is 116°C, and the crystallinity is 7.7%.

[0159] Comparative Example 4

[0160] (1) The polymerization reaction equipment was operated by double-row pipes for three cycles, and then 2 L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH(CH3)2-, R2 is H, and X is chlorine) (2.260 mmol) were added. The mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; the evenly dispersed mixed system was heated to 30° C., ethylene monomer was introduced to maintain a constant pressure (8 bar) atmosphere, and then methylaluminoxane (MAO) (0.679 mol) was added to initiate ethylene polymerization. After 30 minutes of polymerization, the introduction of ethylene monomer was stopped; and triphenylphosphine (2.260 mmol) was added to the obtained polyethylene product.

[0161] Nitrogen was introduced into the polymerization device to purge the unpolymerized ethylene monomer. After the ethylene monomer was completely removed, 392 g of butadiene was added, and a constant pressure (3 bar) atmosphere was maintained. Diisobutylaluminum chloride (0.679 mol) was injected to initiate the copolymerization reaction of butadiene and polyethylene. The copolymerization reaction temperature was 45° C. and the copolymerization reaction time was 3 h.

[0162] The polymerization product was post-treated according to the method of Example 1 to obtain 4535.3 g of ethylene-butadiene polymer D.

[0163] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for polyethylene segment peaks); the polyethylene segment content was 45.5 wt%, the polybutadiene rubber segment content was 54.5 wt%; the 1,2-structure content in the polybutadiene rubber segment was 63.2 mol%;

[0164] The DSC test data show that the melting temperature of the ethylene-butadiene polymer is Tm = 137.1°C, the crystallization temperature is Tc = 119.2°C, and the crystallinity is 36.4%.

[0165] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 255,000 and the molecular weight distribution is 5.77.

[0166] Comparative Example 5

[0167] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technology, and then 2 L of toluene and the catalyst shown in Formula 1 (wherein R1 is 2,6-CH(CH3)2-, R2 is H, and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed evenly by rapid stirring using a mechanical stirrer; 373 g of butadiene was added, and after ethylene monomer was introduced to maintain a constant pressure (6.5 bar) atmosphere, diisobutylaluminum chloride (0.679 mol) and methylaluminoxane (MAO) (0.679 mol) were injected to initiate the copolymerization reaction of butadiene and ethylene, and the copolymerization reaction temperature was 45° C. After 25 minutes, the introduction of ethylene monomer was stopped, and the copolymerization reaction time was 3 hours;

[0168] The polymerization product was post-treated according to the method of Example 1 to obtain 393.2 g of ethylene-butadiene polymer D5.

[0169] (2) The obtained ethylene-butadiene polymer was characterized by: H NMR spectrum (ppm) (chemical shifts were 5 and 5.4 for polybutadiene segment peaks, 1.10 for polyethylene segment peaks); the polyethylene segment content was 25.4 wt%, the polybutadiene rubber segment content was 74.6 wt%; the 1,2-structure content in the polybutadiene rubber segment was 64.3 mol%;

[0170] The DSC test data showed no obvious melting peak or crystallization peak;

[0171] According to GPC test data, the number average molecular weight of the ethylene-butadiene polymer is 63,000 and the molecular weight distribution is 4.79.

[0172] It can be seen from the examples and comparative examples that as the content of ethylene segments in the polymer increases, the Tm of the polymer tends to increase, the crystallinity also tends to increase, the 1,2-structure content of the butadiene segment tends to decrease but remains above 65%, the molecular weight is between 150,000 and 600,000, and the molecular weight distribution tends to widen but remains within 5. Comparative Example 1 is 1,2-polybutadiene, with a narrow distribution and no crystallinity. Compared with Comparative Examples 2-3, polymers with the same ethylene content have a low Tm. In Comparative Example 4, the ethylene segment structure content exceeds 40%, the crystallinity is improved, but the 1,2-structure content of the butadiene segment is reduced to below 65% and the polymer distribution is further widened to 5.77. In Comparative Example 5, by adding ethylene and butadiene monomers together, the 1,2-structure content of the butadiene segment is reduced to below 65% and the molecular weight of the resulting polymer is reduced.

[0173] Test Case

[0174] Mixing and vulcanization: The ethylene-butadiene polymer prepared in the example, and the high vinyl polybutadiene rubber, and the blend of polyethylene and high vinyl polybutadiene rubber prepared in the comparative example were prepared into vulcanized rubber samples by the following methods:

[0175] 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.

[0176] Preparation of vulcanized rubber samples: After the obtained rubber mix 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.

[0177] Table 1

[0178]

[0179]

[0180] The breaking strength and tear strength of the prepared vulcanized rubber samples were measured, wherein the breaking 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.

[0181] Table 2

[0182] Breaking strength MPa Tear strength KN / m Example 1 17.2 43.7 Example 2 16.9 43.0 Example 3 20.1 58.8 Example 4 19.2 57.5 Example 5 17.8 47.3 Example 6 21.5 68.3 Example 7 18.5 51.1 Example 8 21.2 65.7 Example 9 18.7 54.2 Example 10 20.8 62.5 Comparative Example 1 15.5 38.3 Comparative Example 2 16 41.7 Comparative Example 3 16.8 42.8 Comparative Example 4 16.4 52.6 Comparative Example 5 12.2 37.2

[0183] From the results in Table 2 and the comparison with the comparative examples, it can be seen that the embodiments 1-10 of the ethylene-butadiene polymer prepared by the one-step polymerization method of the present invention have better reinforcement effect, and the fracture strength and tear strength of the vulcanized rubber are higher, and they show an upward trend with the increase of the polyethylene segment content. The crystallinity also shows an upward trend with the increase of the polyethylene content, and with the increase of the crystallinity, the fracture strength and tear strength of the vulcanized rubber show an upward trend. Relative to comparative examples 2-3, the embodiments 5 and 7 with the same ethylene content have low crystallinity, high fracture strength and tear strength of the vulcanized rubber, reflecting the improvement of the mechanical properties of the vulcanized rubber by in-situ dispersion. In comparative example 4, the ethylene segment content is further increased, and the tear strength maintains a high strength, but the fracture strength is reduced. The molecular weight of the polymer obtained in comparative example 5 is low, and the fracture strength and tear strength of the vulcanized rubber are not high.

[0184] 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 polybutadiene 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 polybutadiene segment is 60-99.9wt%; in the polybutadiene segment, based on the total molar amount of the polybutadiene segment, the content of 1,2-structure is 60-90mol%.

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 1-30 wt %, and the content of the polybutadiene segment is 70-99 wt %.

3. The ethylene-butadiene polymer according to claim 1 or 2, wherein In the polybutadiene segment, the content of 1,2-structure is 65-85 mol% based on the total molar amount of the polybutadiene segment.

4. The ethylene-butadiene polymer according to any one of claims 1 to 3, wherein The melting temperature Tm of the ethylene-butadiene polymer is 120-150°C, preferably 125-145°C; Preferably, the crystallinity of the ethylene-butadiene polymer is 0.2-30%, preferably 0.5-25%; Preferably, the number average molecular weight of the ethylene-butadiene polymer is 100,000-800,000, preferably 150,000-600,000; Preferably, the molecular weight distribution of the ethylene-butadiene polymer is 2.5-6.5, preferably 3-5.

5. A method for preparing an ethylene-butadiene polymer, characterized in that: The preparation method comprises: (1) in the presence of an organic solvent and a catalyst, using an aluminum-containing cocatalyst-1 to initiate a polymerization reaction of ethylene monomer to obtain a polyethylene product; (2) adding a phosphine-containing additive 1 to the polyethylene product; (3) adding an organic solution containing butadiene and an aluminum-containing co-catalyst-2 to the mixed system obtained in step (2) in sequence to initiate a copolymerization reaction between the butadiene monomer and the polyethylene active chain segment in the polyethylene product to obtain the ethylene-butadiene polymer.

6. The preparation method according to claim 5, wherein: In step (1), the catalyst is a cobalt-containing organic compound; Preferably, the catalyst is selected from the compound represented by Formula 1 and / or the compound represented by Formula 2: wherein X is chlorine or bromine; R1 is H, or a monosubstituted substituent at position 2 or 4 on the benzene ring, or a disubstituted substituent at positions 2, 4 or 2, 6 on the benzene ring that is the same or different, or a trisubstituted substituent at positions 2, 4, and 6 on the benzene ring that is the same or different, 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 is monosubstituted at the 4-position of the dihydrooxazole ring; R2 and R4 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.

7. The preparation method according to claim 5 or 6, wherein: The aluminum-containing co-catalyst-1 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 selected from at least one of methylaluminoxane, methylaluminum modified with triisobutylaluminum, diisobutylaluminum chloride, diethylaluminum chloride and ethylaluminum sesquichloride.

8. The preparation method according to any one of claims 5 to 7, wherein: In step (2), the phosphine-containing auxiliary agent is selected from at least one of triphenylphosphine, tri(3-methylphenyl)phosphine, tri(3-methoxyphenyl)phosphine, isopropyldiphenylphosphine, isopropyldiphenylphosphine and tert-butyldiphenylphosphine, preferably selected from triphenylphosphine and / or isopropyldiphenylphosphine.

9. The preparation method according to any one of claims 5 to 8, wherein: The aluminum-containing co-catalyst-2 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 and n-octylaluminum dichloride, preferably at least one of diisobutylaluminum chloride, diethylaluminum chloride and ethylaluminum sesquichloride.

10. The preparation method according to any one of claims 5 to 9, wherein: The catalyst: the aluminum-containing co-catalyst-1 and the aluminum-containing co-catalyst-2 have a molar ratio of 1:15-1000:20-1000, preferably 1:20-900:40-900; Preferably, the molar ratio of the catalyst to the phosphine-containing auxiliary agent 1 is 1:0.5-2, preferably 1:0.8-1.5; Preferably, the amount of the catalyst used is 0.3-16 mmoL, preferably 0.4-12 mmoL, relative to 1 mmoL of ethylene.

11. The preparation method according to any one of claims 5 to 10, wherein: In step (1), the polymerization reaction temperature is 20-70° C., preferably 30-60° C.; the polymerization reaction pressure is 1-70 bar, preferably 2.5-50 bar; the polymerization reaction time is 1-80 min, preferably 2-60 min; 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.

12. The preparation method according to any one of claims 5 to 11, wherein: In step (3), the concentration of the organic solution containing butadiene is 0.4-12 mol / L, preferably 0.6-9 mol / L; Preferably, the copolymerization reaction temperature is 30-70°C, preferably 40-60°C; the copolymerization reaction pressure is 1-10 bar, preferably 2-5 bar; and the copolymerization reaction time is 2-7 h, preferably 3-6 h.

13. An ethylene-butadiene polymer obtained by the preparation method according to any one of claims 5 to 12.

14. A vulcanized rubber obtained from a composition comprising the ethylene-butadiene polymer according to any one of claims 1 to 4 and 13.

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