Ethylene-isoprene polymer, preparation method thereof and vulcanized rubber

Abstract

The invention relates to the field of synthetic rubber, and discloses an ethylene-isoprene polymer, a preparation method thereof and vulcanized rubber. The ethylene-isoprene polymer comprises a polyethylene chain segment and a polyisoprene chain segment; based on the total weight of the ethylene-isoprene polymer, the content of a polyethylene chain segment is 0.1-40 wt%, and the content of a polyisoprene chain segment is 60-99.9 wt%; based on the total molar weight of the polyisoprene chain segment, the content of the cis-1, 4-structure is 80-95 mol%; based on the total weight of the ethylene-isoprene polymer, the content of toluene insoluble substances is 0.3-6.5 wt%. The polyethylene chain segment in the ethylene-isoprene polymer can modify the polyisoprene chain segment, so that the problems of phase separation, interface failure and the like caused by direct blending of polyethylene and isoprene rubber in the traditional process are solved; the aging property of vulcanized rubber prepared from the ethylene-isoprene polymer is remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of synthetic rubber, in particular to an ethylene-isoprene 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 isoprene 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] Due to its own structure, polyethylene has excellent tensile strength, tear strength, corrosion resistance, electrical insulation, anti-slip properties, low heat generation and aging resistance. These excellent properties of polyethylene can be effectively utilized to improve the performance of rubber, such as improving the aging resistance of polyisoprene rubber products, thereby improving the performance and service life of polyisoprene rubber products.

[0004] However, polyethylene is a plastic, while isoprene rubber is an elastomer. The difference in properties between the two materials leads to poor dispersibility in pure mechanical mixing, and the desired goal cannot be achieved. Therefore, providing a polyethylene isoprene rubber polymer 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 shortcomings of the prior art polyisoprene rubber material, that is, the aging performance is poor, and an ethylene-isoprene polymer and a preparation method thereof and a vulcanized rubber are provided. The ethylene-isoprene polymer comprises polyethylene segments and polyisoprene segments distributed in blocks, wherein the polyethylene segments can achieve the modification of the polyisoprene segments, thereby avoiding the problems of phase separation and interface failure existing in the direct blending of polyethylene and isoprene rubber in the traditional process, and the polymer comprises a specific content of toluene insoluble matter, so that the aging performance and mechanical properties of the vulcanized rubber prepared from the ethylene-isoprene polymer are significantly improved.

[0006] In order to achieve the above object, the first aspect of the present invention provides an ethylene-isoprene polymer, wherein the ethylene-isoprene polymer comprises a polyethylene segment and a polyisoprene segment; based on the total weight of the ethylene-isoprene polymer, the content of the polyethylene segment is 0.1-40wt%, and the content of the polyisoprene segment is 60-99.9wt%; in the polyisoprene segment, based on the total molar amount of the polyisoprene segment, the content of cis-1,4-structure is 80-95mol%;

[0007] The toluene insoluble matter may be contained in an amount of 0.2 to 7 wt % based on the total weight of the ethylene-isoprene polymer.

[0008] A second aspect of the present invention provides a method for preparing an ethylene-isoprene polymer, the method comprising:

[0009] (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;

[0010] (2) adding isoprene and aluminum-containing co-catalyst-2 to the mixed system obtained in step (1) in sequence to initiate a copolymerization reaction between the isoprene monomer and the polyethylene active chain segment in the polyethylene product to obtain the ethylene-isoprene polymer.

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

[0012] A fourth aspect of the present invention provides a vulcanized rubber prepared from the ethylene-isoprene polymer of the present invention.

[0013] Through the above technical scheme, the ethylene-isoprene polymer and the preparation method thereof and the vulcanized rubber provided by the present invention achieve the following beneficial effects:

[0014] The ethylene-isoprene polymer provided by the present invention comprises polyethylene segments and polyisoprene segments distributed in blocks, and contains a specific content of toluene insoluble matter. The polyethylene segments can achieve modification of the polyisoprene segments, thereby avoiding the problems of phase separation, interface failure and the like existing in the direct blending of polyethylene and isoprene rubber in the traditional process, so that the aging performance of the vulcanized rubber prepared from the ethylene-isoprene polymer is significantly improved.

[0015] In the method for preparing an ethylene-isoprene polymer provided by the present invention, a one-step polymerization process is adopted in the presence of a catalyst to simultaneously synthesize polyethylene and polyisoprene, and a polymer comprising polyethylene segments and polyisoprene segments in block distribution is obtained by in-situ polymerization, and an ethylene-isoprene polymer with good compatibility and dispersibility can be obtained without subsequent compounding or blending. 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-isoprene polymer, characterized in that the ethylene-isoprene polymer comprises a polyethylene segment and a polyisoprene segment; based on the total weight of the ethylene-isoprene polymer, the content of the polyethylene segment is 0.1-40wt%, and the content of the polyisoprene segment is 60-99.9wt%; in the polyisoprene segment, based on the total molar amount of the polyisoprene segment, the content of the cis-1,4-structure is 80-95mol%;

[0018] The toluene insoluble matter may be contained in an amount of 0.2 to 7 wt % based on the total weight of the ethylene-isoprene polymer.

[0019] In the present invention, the ethylene-isoprene polymer contains polyethylene segments and polyisoprene segments distributed in blocks, and the polyethylene segments can achieve modification of the polyisoprene segments, thereby avoiding the problems of phase separation and interface failure existing in the direct blending of polyethylene and isoprene rubber in the traditional process, so that the aging performance of the vulcanized rubber prepared from the ethylene-isoprene polymer is significantly improved, and the ethylene-isoprene polymer contains a specific content of toluene insoluble matter, which can reinforce the vulcanized rubber and further improve the mechanical properties and anti-aging performance of the vulcanized rubber.

[0020] Furthermore, when the contents of the polyethylene segment and the polyisoprene segment in the ethylene-isoprene polymer and the content of the cis-1,4 structure in the polyisoprene segment meet the above ranges, the aging properties of the vulcanizate prepared from the ethylene-isoprene polymer are further improved.

[0021] 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.

[0022] In the present invention, the content of toluene insoluble matter in the ethylene-isoprene polymer is measured with reference to SH / T1050-2014.

[0023] In some preferred embodiments of the present invention, preferably, based on the total weight of the ethylene-isoprene polymer, the content of the polyethylene segment is 2-32 wt %, and the content of the isoprene segment is 68-98 wt %.

[0024] In some preferred embodiments of the present invention, preferably, in the isoprene segment, based on the total molar amount of the isoprene segment, the content of cis-1,4-structure is 85-93 mol%.

[0025] In some preferred embodiments of the present invention, preferably, based on the total weight of the ethylene-isoprene polymer, the content of toluene insoluble matter is 0.3-6.5 wt %.

[0026] In the present invention, the contents of polyethylene segments and polyisoprene segments in the ethylene-isoprene polymer, and the content of cis-1,4-structure in the polyisoprene segment are measured by hydrogen nuclear magnetic spectrum.

[0027] In some preferred embodiments of the present invention, the number average molecular weight of the ethylene-isoprene polymer is 80,000-800,000, and the molecular weight distribution is 2 to 5. Preferably, the number average molecular weight of the ethylene-isoprene polymer is 100,000-600,000, and the molecular weight distribution is 2.5 to 4.5.

[0028] In the present invention, the number average molecular weight and molecular weight distribution of the ethylene-isoprene polymer are measured by GPC method.

[0029] 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 %.

[0030] In the present invention, the polyethylene segment content in the toluene insoluble matter is measured by hydrogen nuclear magnetic spectrum.

[0031] 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-isoprene polymer without phase separation, so that the mechanical properties and anti-aging properties of the prepared vulcanized rubber are further improved.

[0032] A second aspect of the present invention provides a method for preparing an ethylene-isoprene polymer, the method comprising:

[0033] (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;

[0034] (2) adding isoprene and aluminum-containing co-catalyst-2 to the mixed system obtained in step (1) in sequence to initiate a copolymerization reaction between the isoprene monomer and the polyethylene active chain segment in the polyethylene product to obtain the ethylene-isoprene polymer.

[0035] In the method for preparing an ethylene-isoprene polymer provided by the present invention, a one-step polymerization process is adopted in the presence of a catalyst to simultaneously synthesize polyethylene and polyisoprene, and in-situ polymerization is performed to obtain a polymer comprising polyethylene segments and polyisoprene segments in block distribution, wherein the polyethylene segments and polyisoprene segments in the polymer are bonded together by chemical bonds, and a polyethylene-compounded polyisoprene rubber having good compatibility and dispersibility can be obtained without the need for subsequent compounding or blending, thereby significantly improving the performance of the polyisoprene rubber. 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, and is conducive to industrial production.

[0036] Specifically, the preparation method provided by the present invention can obtain the ethylene-isoprene polymer comprising a specific content of polyethylene segments and polyisoprene segments as described in the first aspect of the present invention, and the polyisoprene segments contain a specific content of cis-1,4-structure.

[0037] In a specific embodiment of the present invention, ethylene polymerization can be performed first, and then copolymerization of polyethylene and isoprene 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.

[0038] In a specific embodiment of the present invention, preferably, the catalyst is a cobalt-based catalyst containing a cobalt organic compound.

[0039] In a specific embodiment of the present invention, preferably, in step (1), the catalyst is selected from compounds having structures shown in Formula 1 and / or Formula 2:

[0040]

[0041] 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;

[0042] 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;

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] In some embodiments of the present invention, preferably, 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 ethylene monomer is initiated.

[0048] In some embodiments of the present invention, preferably, 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. In the present invention, under the joint action of the catalyst and the aluminum-containing co-catalyst-2, the copolymerization reaction of isoprene monomer and polyethylene is initiated.

[0049] In some embodiments of the present invention, preferably, the molar ratio of the catalyst: the aluminum-containing co-catalyst-1: the aluminum-containing co-catalyst-2 is 1:20-1000:20-1000, preferably 1:50-900:50-900. 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 the control of the content of the polyethylene segment and the polyisoprene segment in the ethylene-isoprene polymer, and the content of the cis-1,4-structure in the polyisoprene segment.

[0050] In some embodiments of the present invention, the amount of the catalyst is 0.3-16mmoL, preferably 0.4-12mmoL, relative to 1moL ethylene. In the present invention, the amount of the catalyst and ethylene is controlled to meet the above range, which can control the ethylene polymerization activity and achieve the regulation of the ethylene segment content of the polymer.

[0051] In some embodiments of the present invention, preferably, in step (1), the polymerization reaction temperature is 20-70°C, preferably 30-60°C; the polymerization reaction pressure is 1-70 bar, preferably 3-40 bar; the polymerization reaction time is 1-80 min, preferably 2-60 min. In the present invention, the polymerization reaction pressure of step (1) can be the gas phase pressure of the fed ethylene monomer.

[0052] In some 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.

[0053] In some embodiments of the present invention, preferably, in step (2), the concentration of the organic solution containing isoprene is 0.4-8 mol / L, preferably 0.6-6 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 organic solution containing isoprene in step (2) satisfies the above range.

[0054] In some embodiments of the present invention, preferably, the copolymerization temperature is 30-70°C, preferably 40-60°C; the copolymerization pressure is 1-10 bar, preferably 2-5 bar; the copolymerization time is 1-7h, preferably 2-6h. In the present invention, the copolymerization pressure of step (2) can be the gas phase pressure of the isoprene monomer fed.

[0055] In some embodiments of the present invention, the amount relationship between ethylene monomer and isoprene can be controlled by the time and pressure of the ethylene monomer being introduced into the polymerization reaction, thereby obtaining the ethylene-isoprene polymer of the present invention. Preferably, the weight relationship of the ethylene monomer and the isoprene monomer meets the amount of the corresponding polyethylene segment and the polyisoprene rubber segment in the obtained ethylene-isoprene polymer, for example, based on the total weight of the ethylene-isoprene polymer, the content of the polyethylene segment is 0.1-40wt%, preferably 2-32wt%, and the content of the polyisoprene segment is 60-99.9wt%, preferably 68-98wt%; based on the total molar amount of the polyisoprene segment, the content of the cis-1,4-structure is 80-95mol%, preferably 85-93mol%.

[0056] In the present invention, when the copolymerization reaction needs to be terminated, the following steps may also be performed:

[0057] 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-isoprene polymer.

[0058] 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.

[0059] In one specific embodiment of the present invention, the method for preparing the ethylene-isoprene polymer comprises the following steps:

[0060] 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 co-catalyst-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-isoprene polymer;

[0061] After reaching the set polymerization reaction time, stop introducing ethylene monomer, add purified isoprene monomer, add aluminum-containing co-catalyst-2 to initiate copolymerization of isoprene monomer and polyethylene active chain segments, and maintain constant pressure for the set time;

[0062] 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 then vacuum dried to obtain the ethylene-isoprene polymer.

[0063] The third aspect of the present invention provides an ethylene-isoprene polymer prepared by the preparation method of the present invention.

[0064] In the present invention, the ethylene-isoprene polymer is as described in the first aspect of the present invention, which will not be described in detail herein.

[0065] A fourth aspect of the present invention provides a vulcanized rubber prepared from the ethylene-isoprene polymer of the present invention.

[0066] The present invention will be described in detail below through examples. In the following examples, the content of polyethylene segments in the ethylene-isoprene polymer, the content of polyisoprene segments, the content of cis-1,4-structure in the polyisoprene segments, and the content of polyethylene segments in toluene insolubles were measured by hydrogen nuclear magnetic spectroscopy.

[0067] The number average molecular weight and molecular weight distribution of ethylene-isoprene polymers were measured by GPC.

[0068] 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.

[0069] The raw materials used in the examples and comparative examples are all commercially available.

[0070] Example 1

[0071] (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 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) (2.260 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 30° C., ethylene monomer was introduced to maintain a constant pressure (7 bar) atmosphere, and then methylaluminoxane (MAO) (0.679 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after 10 minutes of polymerization;

[0072] 300 g (4.41 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (3 bar). Diisobutylaluminum chloride (0.679 mol) was injected to initiate the copolymerization of isoprene and polyethylene. The copolymerization temperature was 45° C. and the copolymerization time was 3 h.

[0073] 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 302.5 g of ethylene-isoprene polymer A1.

[0074] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment was 1.10); the polyethylene segment content was 10.7 wt %, and the polyisoprene rubber segment content was 89.3 wt %; in the polyisoprene rubber segment, the cis-1,4-structure content was 90.4 mol %;

[0075] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 229,000 and the molecular weight distribution is 3.43.

[0076] According to the toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 1.4 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 91.5 wt %.

[0077] Example 2

[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-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) (2.260 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 37° C., ethylene monomer was introduced to maintain a constant pressure (5 bar) atmosphere, and then methylaluminoxane (MAO) (1.36 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after 5 minutes of polymerization;

[0079] 400 g (5.88 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (2 bar). Diisobutylaluminum chloride (0.679 mol) was injected to initiate the copolymerization of isoprene. The copolymerization temperature was 48° C., and the copolymerization time was 4 h.

[0080] The polymerization product was post-treated according to the method of Example 1 to obtain 366.2 g of ethylene-isoprene polymer A2.

[0081] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of 5.24 for the polyisoprene segment peak and 1.10 for the polyethylene segment peak); the content of the polyethylene segment was 2.8 wt %, and the content of the polyisoprene segment was 97.2 wt %; in the polyisoprene rubber segment, the content of the cis-1,4-structure was 92.6 mol %;

[0082] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 294,000 and the molecular weight distribution is 2.82.

[0083] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 0.4 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 94.6 wt %.

[0084] Example 3

[0085] (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 2,6-F- (other substitution positions on the benzene ring are hydrogen), R2 is 4-CF3- (while other substitution positions 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 40° C., ethylene monomer was introduced to maintain a constant pressure (15 bar) atmosphere, and then triisobutylaluminum-modified methylaluminoxane (MMAO) (0.904 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after 12 minutes of polymerization;

[0086] Add 630 g (9.26 mol) of isoprene, maintain a constant pressure (2.5 bar) atmosphere, inject diisobutylaluminum chloride (0.679 mol) to initiate isoprene copolymerization, the copolymerization temperature is 50° C., and the copolymerization time is 4.5 h;

[0087] The polymerization product was post-treated according to the method of Example 1 to obtain 660.2 g of ethylene-isoprene polymer A3.

[0088] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment peak was 1.10); the content of polyethylene segment was 13.7 wt %, and the content of polyisoprene segment was 86.3 wt %; the content of cis-1,4-structure in the polyisoprene rubber segment was 89.6 mol %;

[0089] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 521,000 and the molecular weight distribution is 3.68.

[0090] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 2.5 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 90.7 wt %.

[0091] Example 4

[0092] (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 substitution positions on the benzene ring are hydrogen), R2 is 4-N(CH3)2- (while other substitution positions on the pyridine ring are hydrogen), and X is bromine) (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 33° C., ethylene monomer was introduced to maintain a constant pressure (6 bar) atmosphere, and then methylaluminoxane (MAO) (1.584 mol) was added to initiate ethylene polymerization, and the reaction time was 18 min; the introduction of ethylene monomer was stopped;

[0093] 280 g (4.12 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (3 bar). Diisobutylaluminum chloride (0.158 mol) was injected to initiate the copolymerization of isoprene. The copolymerization temperature was 53° C. and the copolymerization time was 3.5 h.

[0094] The polymerization product was post-treated according to the method of Example 1 to obtain 301.7 g of ethylene-isoprene polymer A4.

[0095] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment peak was 1.10); the content of polyethylene segment was 15.9 wt %, and the content of polyisoprene segment was 84.1 wt %; in the polyisoprene rubber segment, the content of cis-1,4-structure was 88.9 mol %;

[0096] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 237,000 and the molecular weight distribution is 3.82.

[0097] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 2.4 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 90.1 wt %.

[0098] Example 5

[0099] (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- (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 bromine) (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 35° C., ethylene monomer was introduced to maintain a constant pressure (5 bar) atmosphere, and then diethylaluminum chloride (0.452 mol) was added to initiate ethylene polymerization, and the reaction time was 60 min; and then the introduction of ethylene monomer was stopped;

[0100] 450 g (6.62 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (2.2 bar). Diisobutylaluminum chloride (2.036 mol) was injected to initiate the copolymerization of isoprene. The copolymerization temperature was 54° C. and the copolymerization time was 3.2 h.

[0101] The polymerization product was post-treated according to the method of Example 1 to obtain 437.8 g of ethylene-isoprene polymer A5.

[0102] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment peak was 1.10); the content of polyethylene segment was 5.9 wt %, and the content of polyisoprene segment was 94.1 wt %; the content of cis-1,4-structure in the polyisoprene rubber segment was 92.2 mol %;

[0103] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 344,000 and the molecular weight distribution is 3.07.

[0104] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 0.8 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 93.1 wt %.

[0105] Example 6

[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 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 48° C., ethylene monomer was introduced to maintain a constant pressure (30 bar) atmosphere, and then di-tert-butylaluminum chloride (0.226 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after the reaction time was 15 min;

[0107] 300 g (4.41 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (3.5 bar). Diethylaluminum chloride (1.584 mol) was injected to initiate the copolymerization of isoprene. The copolymerization temperature was 58° C., and the copolymerization time was 3.2 h.

[0108] The polymerization product was post-treated according to the method of Example 1 to obtain 395.0 g of ethylene-isoprene polymer A6.

[0109] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment peak was 1.10); the polyethylene segment content was 31.6 wt %, and the polyisoprene segment content was 68.4 wt %; in the polyisoprene rubber segment, the cis-1,4-structure content was 85.4 mol %;

[0110] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 313,000 and the molecular weight distribution is 4.47.

[0111] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 6.3 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 85.7 wt %.

[0112] Example 7

[0113] (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-N(CH3)2-6-CH2CH3- (other substitution positions on the pyridine ring substituted by R3 are hydrogen), R4 is 4-OCH3- (other substitution positions on the pyridine ring substituted by R4 are hydrogen), and X is bromine) (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., 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 16 min;

[0114] 470 g (6.91 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (3.5 bar). Ethyl aluminum sesquihydrate (0.684 mol) was injected to initiate the copolymerization of isoprene monomer. The copolymerization temperature was 60° C. and the copolymerization time was 3.8 h.

[0115] The polymerization product was post-treated according to the method of Example 1 to obtain 544 g of ethylene-isoprene polymer A7.

[0116] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment was 1.10); the polyethylene segment content was 22.8 wt %, and the polyisoprene rubber segment content was 77.2 wt %; in the polyisoprene rubber segment, the cis-1,4-structure content was 87.5 mol %;

[0117] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 434,000 and the molecular weight distribution is 4.17.

[0118] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 5.7 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 88.2 wt %.

[0119] Example 8

[0120] (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-CF3-6-C6H5- (other substitution positions on the pyridine ring substituted by R3 are hydrogen), R4 is hydrogen (and 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 55° C., ethylene monomer was introduced to maintain a constant pressure (24 bar) atmosphere, and then methylaluminoxane (MAO) (1.584 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after 25 minutes of polymerization;

[0121] 580 g (8.53 mol) of isoprene was added, and a constant pressure (2.5 bar) atmosphere was maintained. Diisoethylaluminum chloride (1.584 mol) was injected to initiate a continuous copolymerization reaction of isoprene. The copolymerization reaction temperature was 55° C., and the copolymerization reaction time was 2.8 h.

[0122] The polymerization product was post-treated according to the method of Example 1 to obtain 660 g of ethylene-isoprene polymer A8.

[0123] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene peak was 5.24, and that of polyethylene segment was 1.10); the polyethylene segment content was 19.7 wt %, and the polyisoprene segment content was 80.3 wt %; in the polyisoprene rubber segment, the cis-1,4-structure content was 87.9 mol %;

[0124] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 515,000 and the molecular weight distribution is 4.02.

[0125] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 5.9 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 89.4 wt %.

[0126] Example 9

[0127] (1) After the polymerization reaction equipment is circulated three times using a double-row pipe operation technique, 1 L of toluene and a catalyst 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) are added, and the mixed system is uniformly dispersed by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system is heated to 42° C., ethylene monomer is introduced to maintain a constant pressure (4 bar) atmosphere, and then methylaluminoxane (MAO) (0.226 mol) is added to initiate ethylene polymerization, and the reaction time is 4 min; the introduction of ethylene monomer is stopped;

[0128] 150 g (2.21 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (3 bar). Diethylaluminum chloride (0.452 mol) was injected to initiate the copolymerization of isoprene monomer. The copolymerization temperature was 50° C. and the copolymerization time was 4.2 h.

[0129] The polymerization product was post-treated according to the method of Example 1 and vacuum dried to obtain 141.2 g of ethylene-isoprene polymer A9.

[0130] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment was 1.10); the polyethylene segment content was 4.4 wt%, and the polyisoprene rubber segment content was 95.6 wt%; in the polyisoprene rubber segment, the cis-1,4-structure content was 92.3 mol%;

[0131] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 112,000 and the molecular weight distribution is 2.89.

[0132] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 0.5 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 93.6 wt %.

[0133] Example 10

[0134] (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-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 uniformly dispersed by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 38° C., ethylene monomer was introduced to maintain a constant pressure (12 bar) atmosphere, and methylaluminoxane (MAO) (0.113 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after the reaction time was 30 min;

[0135] 190 g (2.79 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (2.8 bar). Diisobutylaluminum chloride (1.131 mol) was injected to initiate the copolymerization of isoprene. The copolymerization temperature was 45° C., and the copolymerization time was 2.4 h.

[0136] The polymerization product was post-treated according to the method of Example 1 to obtain 223.5 g of ethylene-isoprene polymer A10.

[0137] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment was 1.10); the polyethylene segment content was 27.5 wt %, and the polyisoprene rubber segment content was 72.5 wt %; in the polyisoprene rubber segment, the cis-1,4-structure content was 86.3 mol %;

[0138] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 187,000 and the molecular weight distribution is 4.32.

[0139] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 4.1 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 87.6 wt %.

[0140] Embodiment 11

[0141] (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 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 uniformly dispersed by rapid stirring using a mechanical stirrer; the uniformly dispersed mixed system was heated to 45° C., ethylene monomer was introduced to maintain a constant pressure (10 bar) atmosphere, and then methylaluminoxane (MAO) (1.034 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after the reaction time was 3 min;

[0142] 470 g (6.91 mol) of isoprene was added, and a constant pressure (4 bar) atmosphere was maintained. Diisobutylaluminum chloride (0.226 mol) was injected to initiate the copolymerization of isoprene. The copolymerization temperature was 43° C. and the copolymerization time was 3 h.

[0143] The polymerization product was post-treated according to the method of Example 1 to obtain 1460.5 g of ethylene-isoprene polymer A1.

[0144] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment peak was 1.10); the content of polyethylene segment was 8.8 wt %, and the content of polyisoprene segment was 91.2 wt %; the content of cis-1,4-structure in the polyisoprene rubber segment was 91.2 mol %;

[0145] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 367,000 and the distribution is 3.22.

[0146] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 1.3 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 92.3 wt %.

[0147] Comparative Example 1

[0148] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 2 L 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) (2.260 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 70° C., 220 g (3.24 mol) of isoprene was added, and a constant pressure (3 bar) atmosphere was maintained, and diisobutylaluminum chloride (1.584 mol) was injected to initiate the polymerization of isoprene monomer, and the reaction time was 4 h;

[0149] The polymerization product was post-treated according to the method of Example 1 to obtain 192.7 g of polyisoprene rubber D1.

[0150] (2) The obtained polyisoprene rubber was characterized: H NMR spectrum (ppm) (polyisoprene rubber peak with chemical shift of 5.24); the content of cis-1,4-structure was 95.2 mol%.

[0151] According to GPC test data, the number average molecular weight of the isoprene rubber is 157,000 and the distribution is 2.75.

[0152] No toluene insoluble matter.

[0153] Comparative Example 2

[0154] The polyisoprene rubber and polyethylene prepared in Comparative Example 1 were solution blended to prepare 164.6 g of a blend D2 of polyethylene and polyisoprene rubber, wherein the content of polyethylene was 5.9 wt % based on the total weight of the blend.

[0155] According to the toluene insoluble matter test data, the toluene insoluble matter content in the blend is 5.9 wt %, and based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 100 wt %.

[0156] Comparative Example 3

[0157] The polyisoprene rubber and polyethylene prepared in Comparative Example 1 were solution blended to prepare 180.2 g of a blend D3 of polyethylene and polyisoprene rubber, wherein the content of polyethylene was 10.7 wt % based on the total weight of the blend.

[0158] According to the toluene insoluble matter test data, the toluene insoluble matter content in the blend is 10.7 wt %, wherein the polyethylene segment content is 100 wt %.

[0159] Comparative Example 4

[0160] (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 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) (2.260 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 30° C., ethylene monomer was introduced to maintain a constant pressure (30 bar) atmosphere, and then methylaluminoxane (MAO) (0.679 mol) was added to initiate ethylene polymerization, and the introduction of ethylene monomer was stopped after 30 minutes of polymerization;

[0161] 300 g (4.41 mol) of isoprene was added, and the atmosphere was kept at a constant pressure (3 bar). Diisobutylaluminum chloride (0.679 mol) was injected to initiate the copolymerization of isoprene and polyethylene. The copolymerization temperature was 45° C. and the copolymerization time was 3 h.

[0162] The polymerization product was post-treated according to the method of Example 1 to obtain 512.3 g of ethylene-isoprene polymer D4.

[0163] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment was 1.10); the polyethylene segment content was 47.3 wt%, and the polyisoprene rubber segment content was 52.7 wt%; in the polyisoprene rubber segment, the cis-1,4-structure content was 79.7 mol%;

[0164] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 400,000 and the molecular weight distribution is 4.86.

[0165] According to toluene insoluble matter test data, the content of toluene insoluble matter in the ethylene-isoprene polymer is 16.6 wt %. Based on the total weight of the toluene insoluble matter, the content of polyethylene segments is 84.6 wt %.

[0166] Comparative Example 5

[0167] (1) The polymerization reaction equipment was circulated three times using a double-row pipe operation technique, and then 2 L 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 (the substitution positions on the pyridine ring are all hydrogen), and X is chlorine) (2.260 mmol) were added, and the mixed system was dispersed uniformly by rapid stirring using a mechanical stirrer; 300 g (4.41 mol) of isoprene was added, and after the ethylene monomer was introduced to maintain a constant pressure (10 bar) atmosphere, diisobutylaluminum chloride (0.679 mol) and methylaluminoxane (MAO) (0.679 mol) were injected to initiate the copolymerization reaction of isoprene and ethylene. The copolymerization reaction temperature was 45° C. After 30 minutes, the introduction of the 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 383.0 g of ethylene-isoprene polymer D5.

[0169] (2) The obtained ethylene-isoprene polymer was characterized: H NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment peak was 1.10); the polyethylene segment content was 30 wt%, and the polyisoprene rubber segment content was 70 wt%; in the polyisoprene rubber segment, the content of cis-1,4-structure was 72.3 mol%;

[0170] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 85,000 and the molecular weight distribution is 4.59.

[0171] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 0.2 wt %. Based on the total weight of the toluene insoluble matter, the polyethylene segment content is 90.2 wt %.

[0172] Comparative Example 6

[0173] 200 g of the ethylene-isoprene polymer obtained in Example 8 was added with about 2 L of toluene and stirred at room temperature for 48 hours until no obvious solids were present. 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 188.3 g of ethylene-isoprene polymer D6.

[0174] The obtained ethylene-isoprene polymer was characterized: H-NMR spectrum (ppm) (chemical shift of 5.24 for the polyisoprene segment peak and 1.10 for the polyethylene segment peak); the content of the polyethylene segment was 15.2 wt %, and the content of the polyisoprene segment was 84.8 wt %; in the polyisoprene rubber segment, the content of the cis-1,4-structure was 87.9 mol %;

[0175] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 522,000 and the molecular weight distribution is 3.94.

[0176] No toluene insoluble matter.

[0177] Comparative Example 7

[0178] 300 mL of a toluene solution containing 17.0 g (0.25 mol) of isoprene was added to a 400 mL pressure-resistant glass reactor that had been fully dried, 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. Then, the catalyst solution was 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 14.2 g of copolymer D7.

[0179] The obtained ethylene-isoprene polymer was characterized by: H-NMR spectrum (ppm) (chemical shift of polyisoprene segment peak was 5.24, and that of polyethylene segment was 1.10); the polyethylene segment content was 12.3 wt%, and the polyisoprene rubber segment content was 87.7 wt%; in the polyisoprene rubber segment, the cis-1,4-structure content was 83.5 mol%;

[0180] According to GPC test data, the number average molecular weight of the ethylene-isoprene polymer is 177,000 and the molecular weight distribution is 4.26.

[0181] According to toluene insoluble matter test data, the toluene insoluble matter content in the ethylene-isoprene polymer is 0.1 wt %. Based on the total weight of the toluene insoluble matter, the content of the polyethylene segment is 81.6 wt %.

[0182] It can be seen from the examples and comparative examples that the ethylene-isoprene polymer of the present invention has a decreasing trend in the cis-1,4-structure content of the isoprene segment as the polyethylene segment content increases, and the molecular weight distribution of the polymer becomes wider. In addition, the polymers prepared by in-situ polymerization in Examples 1-11 have a toluene insoluble content of 0.4-6.3 wt%.

[0183] In Comparative Example 4, when the polyethylene segment content in the obtained polymer exceeded 40wt%, the cis-1,4 structure content of the isoprene segment decreased to less than 80%. In Comparative Example 5, when a one-step polymerization method was adopted, the cis-1,4 structure content of the isoprene segment in the obtained polymer was further reduced, and the number average molecular weight of the obtained polymer was reduced to less than 100,000.

[0184] 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, compared with Example 8, after filtering through a stainless steel mesh, the polyethylene segment content of the obtained polymer decreases, and there is no toluene insoluble matter. The polymer of Comparative Example 7 has a low toluene insoluble matter content.

[0185] Test Case

[0186] Mixing and vulcanization: The ethylene-isoprene polymers prepared in Examples 1-11, and the polyisoprene rubber, the blend of polyethylene and polyisoprene, and the ethylene-isoprene polymer provided in the comparative examples were prepared into vulcanized rubber samples by the following methods:

[0187] 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.

[0188] 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.

[0189] Table 1

[0190] Adding time (min) Additives and fillers (weight) 0-1 Polymer, 100 parts 1-2 ZnO, 4 parts; stearic acid, 1.5 parts 2-3 Antioxidant 4010NA, 1 part 3-6 N330, 50 copies 6-7 Accelerator CZ, 1 part; Accelerator D, 0.5 part 7-13 Mixing 13-14 Sulfur S, 1.5 parts 14-15 Discharging

[0191] The prepared vulcanized rubber samples were tested according to the standard GB / T 528-1998 to obtain the breaking strength of the vulcanized rubber. The breaking strength change rate was tested according to GB / T3512-2001. The aging conditions were 100° C. and 48 hours. The results are shown in Table 2.

[0192] Table 2

[0193]

[0194]

[0195] From the results in Table 2 and the comparison with the comparative examples, it can be seen that the vulcanized rubbers prepared from the ethylene-isoprene polymers of Examples 1-11 have higher breaking strength than the comparative example 1 in which the vulcanized rubber is prepared from polyisoprene rubber alone, and show a smaller breaking strength change rate after 48 hours of thermal oxidation aging at 100°C, indicating better aging resistance, and the aging resistance increases with the increase of polyethylene content. Compared with comparative examples 2 and 3 in which polyethylene and isoprene rubber are physically blended, when the same content of polyethylene segments is in situ polymerized with isoprene segments by the one-step polymerization method provided by the present invention to form ethylene-isoprene polymers, the breaking strength and aging resistance of the vulcanized rubber obtained thereby are more excellent. The polymer of comparative example 4 has a high content of ethylene segments, and has better aging resistance but reduced breaking strength. The polymer of comparative example 5 has a low molecular weight, and the aging resistance of the vulcanized rubber is better, but the breaking strength decreases. In Comparative Example 6, after the toluene insoluble matter removal process, the mechanical properties of the obtained polymer vulcanizate decreased, which was lower than that of Example 8 and Example 3 and Example 1 with lower polyethylene segment content, indicating that the toluene insoluble matter has a good reinforcing effect on the vulcanizate and can improve the mechanical properties and anti-aging properties of the vulcanizate. In Comparative Example 7, although the polyethylene segment content in the ethylene-isoprene polymer is higher than that in Example 1 and Example 11, due to the low content of toluene insoluble matter in Comparative Example 7, the fracture strength and aging properties of the vulcanizate are inferior to those of Example 1 and Example 11.

[0196] 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-isoprene polymer, characterized in that The ethylene-isoprene polymer comprises a polyethylene segment and a polyisoprene segment; based on the total weight of the ethylene-isoprene polymer, the content of the polyethylene segment is 0.1-40wt%, and the content of the polyisoprene segment is 60-99.9wt%; in the polyisoprene segment, based on the total molar amount of the polyisoprene segment, the content of the cis-1,4-structure is 80-95mol%; The toluene insoluble matter may be contained in an amount of 0.2 to 7 wt % based on the total weight of the ethylene-isoprene polymer.

2. The ethylene-isoprene polymer according to claim 1, wherein Based on the total weight of the ethylene-isoprene polymer, the content of the polyethylene segment is 2-32 wt %, and the content of the isoprene segment is 68-98 wt %.

3. The ethylene-isoprene polymer according to claim 1 or 2, wherein In the polyisoprene segment, the content of cis-1,4-structure is 85-93 mol % based on the total molar amount of the polyisoprene segment.

4. The ethylene-isoprene polymer according to any one of claims 1 to 3, wherein The number average molecular weight of the ethylene-isoprene polymer is 80,000-800,000, and the molecular weight distribution is 2-5; Preferably, the number average molecular weight of the ethylene-isoprene polymer is 100,000-600,000, and the molecular weight distribution is 2.5-4.

5.

5. The ethylene-isoprene polymer according to any one of claims 1 to 4, wherein Based on the total weight of the ethylene-isoprene polymer, the content of toluene insoluble matter is 0.3-6.5wt%; Preferably, the content of the polyethylene segment is 85-95 wt % based on the total weight of the toluene insoluble matter.

6. A method for preparing an ethylene-isoprene polymer, the method comprising: (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 an organic solution containing isoprene and an aluminum-containing co-catalyst-2 to the mixed system obtained in step (1) in sequence to initiate a copolymerization reaction between the isoprene monomer and the polyethylene active chain segment in the polyethylene product to obtain the ethylene-isoprene polymer.

7. The preparation method according to claim 6, wherein: In step (1), the catalyst is a cobalt-containing organic compound; Preferably, the catalyst is selected from compounds having structures shown in Formula 1 and / or 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 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; 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.

8. The preparation method according to claim 6 or 7, 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.

9. The preparation method according to any one of claims 6 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 6 to 9, wherein: The molar ratio of the catalyst, the aluminum-containing co-catalyst-1 and the aluminum-containing co-catalyst 2 is 1:20-1000:20-1000, preferably 1:50-900:50-900; 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 6 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 3-40 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 6 to 11, wherein: In step (2), the concentration of the isoprene-containing organic solution is 0.4-8 mol / L, preferably 0.6-6 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 1-7 h, preferably 2-5 h.

13. An ethylene-isoprene polymer obtained by the preparation method according to any one of claims 6 to 12.

14. A vulcanized rubber obtained from the ethylene-isoprene polymer according to any one of claims 1 to 5 and 12.

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