A hyperbranched polyethylene polymer, preparation method and application thereof

Abstract

The present invention provides a hyperbranched polyethylene-based polymer, a preparation method thereof, and applications thereof. The side chains of the hyperbranched polyethylene-based polymer are polyethylene, and the main chain is hyperbranched polyethylene. The hyperbranched polyethylene main chain forms a rubber phase, and the crystalline, low-molecular-weight polyethylene side chains form a plastic phase. The plastic phase is randomly and randomly distributed along the main chain to form a reversible physical crosslink and runs through the rubber phase, so that the hyperbranched polyethylene-based polymer has the characteristics of a thermoplastic elastomer. At the same time, the present invention introduces a polar olefin monomer into the main chain to give the hyperbranched polyethylene-based polymer a higher polarity, which can greatly improve its compatibility with materials such as polar pigments, glass fibers, clay, and metals, thereby improving the performance of the composite material.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of polyolefin materials, and in particular relates to a hyperbranched polyethylene-based polymer, a preparation method and application thereof. Background Art

[0002] Thermoplastic elastomers, also known as synthetic rubber, combine the high elasticity of traditional vulcanized rubber with the thermoplasticity and recyclability of ordinary plastics. Their thermoplasticity and crosslinking reinforcement rely on reversible physical crosslinks formed within the plastic phase, unlike traditional vulcanized rubber. Traditional vulcanized rubber is typically reinforced through chemical crosslinking, which is irreversible, making it difficult to recycle and reuse, and causing significant environmental pollution.

[0003] As an important branch of polyolefin-based thermoplastic elastomers, copolymer polyolefin-based thermoplastic elastomers include polyolefin elastomers (POE), propylene-based elastomers (PBE), olefin block copolymers (OBC) and polypropylene-based block copolymers. The polymer chain is a combination of segments with a higher melting point and providing crystallinity and segments with a lower glass transition point and providing amorphous segments. The crystalline segments form the plastic phase and the amorphous segments form the rubber phase. The plastic phase is distributed in the rubber phase, and reversible physical crosslinks are formed between the plastic phases, providing a strength basis for the elastomer to exert its elasticity. The reversible physical crosslinks also make it thermoplastic and recyclable.

[0004] Although copolymer polyolefin-based thermoplastic elastomers can be divided into random copolymers (such as POE and PBE) and block copolymers (such as OBC and polypropylene-based block copolymers) based on chain structure, the crystalline and amorphous segments within each polymer chain are randomly distributed along the polymer backbone. Furthermore, the lack of polar groups in the polyolefin molecular structure results in poor compatibility with other materials, such as polar pigments, glass fiber, clay, and metals, which limits the further application of polyolefin materials. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a hyperbranched polyethylene polymer, a preparation method and application thereof. The hyperbranched polyethylene polymer has excellent thermoplastic elastomer characteristics.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a hyperbranched polyethylene-based polymer, wherein the side chains are polyethylene and the main chain is hyperbranched polyethylene;

[0008] The hyperbranched polyethylene-based polymer is a terpolymer of ethylene, polyethylene and a polar olefin monomer.

[0009] Preferably, the melting point of the polyethylene in the side chain is 80-100°C, and the weight average molecular weight is 8.0×10 2 ~3.0×10 3 g / mol, the molecular weight distribution index is 1.0 to 3.0, and the chain end double bond content is greater than 85%.

[0010] Preferably, the molar insertion amount of polyethylene in the hyperbranched polyethylene-based polymer is 3 to 7.5%.

[0011] Preferably, the molar insertion amount of the polar vinyl monomer in the hyperbranched polyethylene polymer is 1 to 4%.

[0012] Preferably, the polar vinyl monomer is selected from any one or more of methyl acrylate, vinyl butyl ether or allyl acetate.

[0013] Preferably, the weight average molecular weight of the hyperbranched polyethylene polymer is 25×10 4 ~45×10 4 g / mol, and the molecular weight distribution index is 2.0 to 5.0.

[0014] In a second aspect, the present invention provides a method for preparing a hyperbranched polyethylene polymer, comprising the following steps:

[0015] S1: mixing ethylene, a solvent, an oligomerization catalyst, and a co-catalyst and performing a homopolymerization reaction to obtain a reaction product containing polyethylene;

[0016] S2: copolymerizing the reaction product obtained in step S1, ethylene and a polar olefin monomer in the presence of a copolymerization catalyst to obtain a hyperbranched polyethylene polymer.

[0017] Preferably, the solvent is selected from any one or more of n-hexane, toluene, cyclohexane or isoparaffin.

[0018] Preferably, the oligomerization catalyst is a single-active-site post-metallocene catalyst, and the single-active-site post-metallocene catalyst is selected from bis(β-diketone imine)benzyl zirconium catalyst and / or 2,6-diiminopyridine iron catalyst.

[0019] Preferably, the cocatalyst is selected from methylaluminoxane compounds and / or modified methylaluminoxane compounds.

[0020] Preferably, the copolymerization catalyst is an α-diimine nickel catalyst, and the α-diimine nickel catalyst is selected from N,N'-bis(2,6-diisopropylphenyl)acenaphthene diimine nickel dibromide catalyst and / or N,N'-bis(2,6-diisopropylphenyl)ethyleneacenaphthene diimine nickel dibromide catalyst.

[0021] Preferably, the polar vinyl monomer is selected from any one or more of methyl acrylate, vinyl butyl ether or allyl acetate.

[0022] Preferably, the molar ratio of the co-catalyst to the oligomerization catalyst is (50-900):1.

[0023] Preferably, the molar ratio of ethylene to oligomerization catalyst is (1.4×10 6 ~1×10 7 ):1.

[0024] Preferably, the molar ratio of the copolymerization catalyst to the oligomerization catalyst is 20:1 to 1:1.

[0025] Preferably, the molar ratio of the polar olefin monomer to ethylene is (0.1-20):1.

[0026] Preferably, the temperature of the homopolymerization reaction and the copolymerization reaction are independently 50 to 90° C., and the pressure is independently 0.1 to 1.0 MPa.

[0027] In a third aspect, the present invention provides an adhesive comprising the hyperbranched polyethylene polymer according to the above technical solution.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The method of the present invention provides a hyperbranched polyethylene-based polymer, which has crystalline, low-molecular-weight polyethylene as side chains and hyperbranched polyethylene as the main chain. The hyperbranched polyethylene main chain forms a rubber phase, and the crystalline, low-molecular-weight polyethylene side chains form a plastic phase. The plastic phase is randomly and randomly distributed along the main chain to form a reversible physical crosslink and runs through the rubber phase. During tensile testing, it was found that the hyperbranched polyethylene-based polymer had no plastic deformation phenomena such as yielding or ductility, and the elongation at break was greater than 900%, and the breaking strength was greater than 5MPa, indicating that it had typical elastomer characteristics. At the same time, the present invention introduces polar olefin monomers into the main chain to make the hyperbranched polyethylene-based polymer have higher polarity, which can greatly improve its compatibility with materials such as polar pigments, glass fibers, clay, and metals, thereby improving the performance of the composite material. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In the prior art, the intrachain structure of copolymerized polyolefin-based polymers is characterized by the random and irregular distribution of crystalline and amorphous segments along the polymer backbone, and the lack of polar groups in their molecular structure, resulting in poor compatibility with other materials. Based on an understanding of polymer chain structure and the design of the rubber-plastic two-phase aggregate structure, the present invention considers using amorphous segments as the polymer backbone and longer crystallizable segments as side chains to synthesize a grafted copolymer. The backbone forms the rubber phase, and the side chain crystalline segments form the plastic phase. These segments are randomly and randomly distributed along the backbone, and reversible physical crosslinks are formed between the plastic phases, running through the rubber phase, ultimately exhibiting the characteristics of a thermoplastic elastomer. Furthermore, the present invention aims to significantly improve the polymer's adhesion, miscibility, dyeability, printability, and compatibility with other materials by introducing polar olefinic monomers into the polymer, thereby expanding its commercial application range.

[0032] Based on the above considerations, the present invention provides a hyperbranched polyethylene-based polymer, whose side chains are polyethylene and whose main chain is hyperbranched polyethylene, wherein the hyperbranched polyethylene-based polymer is a terpolymer of ethylene, polyethylene, and a polar olefin monomer. In the present invention, the side-chain polyethylene is obtained by homopolymerization of ethylene in the presence of a solvent, an oligomerization catalyst, and a cocatalyst, wherein the solvent is selected from any one or more of n-hexane, toluene, cyclohexane, or an isoparaffin, and the isoparaffin can be isobutane, isopentane, or Isopar E; the oligomerization catalyst catalyzes the homopolymerization of ethylene to produce crystalline, low-molecular-weight polyethylene, and is a single-active-center post-metallocene catalyst, specifically selected from a bis(β-diketoimidate)benzyl zirconium catalyst and / or a 2,6-diiminopyridine iron catalyst, and the cocatalyst is selected from a methylaluminoxane compound and / or a modified methylaluminoxane compound. The side chain polyethylene has a melting point (i.e., melting peak) of 80-100°C, which may be 80°C, 82°C, 85°C, 88°C, 90°C, 92°C, 95°C, 98°C or 100°C, and a weight average molecular weight of 8.0×10 2 ~3.0×10 3 g / mol, which can be 8.0×10 2 g / mol, 9.0×10 2 g / mol, 1.0×10 3 g / mol, 2×10 3 g / mol or 3×10 3 g / mol, and a molecular weight distribution index of 1.0 to 3.0, which may be 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, or 3. These values ​​indicate that the polyethylene is a crystalline, low-molecular-weight polyethylene. Furthermore, the polyethylene has a terminal double bond content of greater than 85% to facilitate subsequent polymerization reactions with ethylene and polar olefinic monomers.

[0033] In the present invention, the hyperbranched polyethylene-based polymer is a terpolymer of ethylene, the above-mentioned crystalline, low molecular weight polyethylene and a polar olefinic monomer. In some embodiments of the present invention, the ternary copolymerization of ethylene, the above-mentioned crystalline, low molecular weight polyethylene and the polar olefinic monomer is carried out in the presence of a copolymerization catalyst, and the copolymerization catalyst catalyzes the polymerization of ethylene to obtain hyperbranched polyethylene, which can be selected from an α-diimine nickel catalyst, and the α-diimine nickel catalyst can be specifically selected from N,N'-bis(2,6-diisopropylphenyl)acenaphthene diimine nickel dibromide and / or N,N'-bis(2,6-diisopropylphenyl)ethyleneacenaphthene diimine nickel dibromide. The polar olefinic monomer is selected from any one or more of methyl acrylate, vinyl butyl ether or allyl acetate. In the present invention, the molar insertion amount of crystalline, low molecular weight polyethylene in the hyperbranched polyethylene polymer is 3 to 7.5%, such as 3%, 4%, 5%, 6%, 7% or 7.5%, and the molar insertion amount of polar olefin monomer in the hyperbranched polyethylene polymer is 1 to 4%, such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5% or 4%. After testing, the weight average molecular weight of the hyperbranched polyethylene polymer is 25×10 4 ~45×10 4 g / mol, which can be 25×10 4 g / mol, 30×10 4 g / mol, 35×10 4 g / mol, 40×10 4 g / mol or 45×10 4 g / mol, etc., and the molecular weight distribution index is 2.0 to 5.0, which can be 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8 or 5, etc.

[0034] The present invention prepares a hyperbranched polyethylene-based polymer by using crystalline, low-molecular-weight polyethylene as side chains and hyperbranched polyethylene as the main chain. The hyperbranched polyethylene main chain forms a rubber phase, and the crystalline, low-molecular-weight polyethylene side chains form a plastic phase. The plastic phase is randomly and randomly distributed along the main chain, forming a reversible physical crosslink and running through the rubber phase. During tensile testing, it was found that the hyperbranched polyethylene-based polymer had no plastic deformation phenomena such as yielding or ductility, and the elongation at break was greater than 900%, and the breaking strength was greater than 5MPa, indicating that it possessed typical elastomer characteristics. At the same time, the present invention introduces polar olefin monomers into the main chain to make the hyperbranched polyethylene-based polymer have high polarity, which can greatly improve its compatibility with materials such as polar pigments, glass fibers, clay, and metals, thereby improving the performance of the composite material.

[0035] The present invention also provides a method for preparing the hyperbranched polyethylene polymer, comprising the following steps:

[0036] S1: homopolymerizing ethylene, a solvent, an oligomerization catalyst, and a co-catalyst to obtain a reaction product containing polyethylene;

[0037] S2: copolymerizing the reaction product obtained in step S1, ethylene and a polar olefin monomer in the presence of a copolymerization catalyst to obtain a hyperbranched polyethylene polymer.

[0038] According to the present invention, ethylene, a solvent, an oligomerization catalyst and a co-catalyst are first subjected to a homopolymerization reaction to obtain a reaction product containing polyethylene. The specific selection of the solvent, oligomerization catalyst and co-catalyst is as described in the relevant contents of the above technical solution, and will not be repeated here. The present invention has no special restrictions on the sources of ethylene, solvent, oligomerization catalyst and co-catalyst, and they can be general commercial products. In some embodiments of the present invention, the molar ratio of the co-catalyst to the oligomerization catalyst is (50 to 900):1, which can be 50:1, 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1 or 900:1, etc. The molar ratio of ethylene to the oligomerization catalyst is (1.4×10 6 ~1×10 7 ):1, can be 1.4×10 6 :1, 2×10 6 :1, 3×10 6 :1, 4×10 6 :1,5×10 6 :1, 6×10 6 :1,7×10 6 :1, 8×10 6 :1,9×10 6 :1 or 1×10 7 :1, etc. The present invention has no special restrictions on the amount of the solvent, as long as the solvent can provide a liquid environment for the above-mentioned homopolymerization reaction. In order to exclude water and oxygen in the solvent, the present invention preferably subjects the solvent to anhydrous and oxygen-free treatment. The present invention has no special restrictions on the method of anhydrous and oxygen-free treatment, and the technical scheme for anhydrous and oxygen-free treatment of solvents well known to those skilled in the art can be adopted. The present invention preferably carries out the above-mentioned reaction under stirring conditions, and the present invention has no special restrictions on the stirring method of the polymerization reaction, and the stirring technical scheme well known to those skilled in the art can be adopted. The stirring rate is 400-800r / min, and can be 400r / min, 450r / min, 500r / min, 550r / min, 600r / min, 650r / min, 700r / min, 750r / min or 800r / min, etc.

[0039] In some embodiments of the present invention, the feed concentration of the polymerization catalyst is 2.5 to 20 μmol / L, which can be 2.5 μmol / L, 3 μmol / L, 5 μmol / L, 8 μmol / L, 10 μmol / L, 13 μmol / L, 15 μmol / L, 18 μmol / L or 20 μmol / L, etc.

[0040] In some embodiments of the present invention, the temperature of the homopolymerization reaction is 50-90°C, which can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, etc., the pressure is 0.1-1.0 MPa, which can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1 MPa, etc., and the time of the homopolymerization reaction is 5-15 min, which can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min or 15 min, etc., preferably 10-12 min.

[0041] In some embodiments of the present invention, a homopolymerization reaction is preferably carried out under an ethylene atmosphere by adding an anhydrous and oxygen-free solvent and, under stirring, adding a cocatalyst and an oligomerization catalyst. After a period of reaction, the ethylene gas flow is stopped, acidified ethanol is added to terminate the reaction, and the reaction product containing polyethylene is collected. In the present invention, the homopolymerization reaction is preferably carried out in a batch polymerization reactor. Prior to the experiment, the reactor is purged with nitrogen 2 to 4 times, preferably 3 times, and ethylene 2 to 4 times, preferably 3 times, at a high temperature of 120 to 160°C, preferably 140°C. The reactor is then cooled to the target temperature under an ethylene atmosphere. The target temperature is the temperature of the homopolymerization reaction.

[0042] The present invention tests the obtained reaction product containing polyethylene and finds that the melting point of polyethylene is 80-100°C and the weight average molecular weight is 8.0×10 2 ~3.0×10 3 g / mol, a molecular weight distribution index of 1.0 to 3.0, and a chain end double bond content greater than 85%. The results show that the polyethylene is a crystalline, low molecular weight polyethylene.

[0043] After obtaining the reaction product containing polyethylene, the present invention preferably copolymerizes the obtained reaction product with ethylene and a polar olefin monomer in the presence of a copolymerization catalyst to obtain a hyperbranched polyethylene polymer. The specific selection of the copolymerization catalyst and the polar olefin monomer is as described in the relevant content of the above technical solution, and will not be repeated here. The present invention has no particular restrictions on the sources of the copolymerization catalyst and the polar olefin monomer, and they can be general commercial products. In some embodiments of the present invention, the molar ratio of the copolymerization catalyst to the oligomerization catalyst is 20:1 to 1:1, which can be 20:1, 18:1, 15:1, 12:1, 10:1, 8:1, 5:1, 2:1 or 1:1, etc.; the molar ratio of the polar olefin monomer to ethylene is (0.1 to 20):1, which can be 0.1:1, 0.5:1, 1:1, 3:1, 5:1, 8:1, 10:1, 12:1, 15:1, 18:1 or 20:1, etc.

[0044] In some embodiments of the present invention, the temperature of the copolymerization reaction is 50-90°C, which can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, etc.; the pressure is 0.1-1.0 MPa, which can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1 MPa, etc.; the time of the copolymerization reaction is 15-40 min, which can be 15 min, 18 min, 20 min, 23 min, 25 min, 28 min, 30 min, 32 min, 35 min, 38 min or 40 min, etc.

[0045] The point values ​​listed above in the present invention are only for illustrative purposes and are not limited thereto. Other point values ​​within the numerical range are applicable. To avoid complexity, they will not be described one by one.

[0046] In some embodiments of the present invention, it is preferred that after the homopolymerization reaction is completed, a copolymerization catalyst and a polar olefin monomer are added to the reaction system without adding acidified ethanol to terminate the reaction, the reaction is continued for a period of time, the ethylene gas feed is stopped, and then acidified ethanol is added to terminate the copolymerization reaction, and the polymerization product is collected, wherein the polymerization product includes a hyperbranched polyethylene polymer.

[0047] The preparation method of the hyperbranched polyethylene polymer provided by the present invention is simple, has a short reaction time, does not require expensive instruments and equipment, is easy to implement, and is conducive to industrial or industrial production. According to tests, the weight average molecular weight of the hyperbranched polyethylene polymer obtained by the present invention is 25×10 4 ~45×10 4g / mol, the molecular weight distribution index is 2.0-5.0, the melting point (Tm) is 80-96°C, and after tensile testing, it was found that it has no plastic deformation phenomena such as yielding or ductility, the elongation at break is greater than 900%, and the breaking strength is greater than 5MPa, indicating that it has typical elastomer characteristics.

[0048] Based on this, the present invention also provides an adhesive, which includes the hyperbranched polyethylene polymer involved in the above technical solution. The adhesive can be used in conventional technical fields well known to those skilled in the art.

[0049] In order to further illustrate the present invention, the following examples are provided for detailed description. The experimental raw materials used in the following examples of the present invention are all commonly available commercial products.

[0050] The "feed concentration" involved in the present invention refers to the initial molar concentration of the material when it enters the reactor based on the reaction volume, and the "molar ratio" refers to the initial molar concentration ratio between the materials.

[0051] Example 1

[0052] In this example, the polymerization reaction temperature was 75°C, the polymerization reaction pressure was 0.87 MPa, the solvent was cyclohexane, the oligomerization catalyst was 2,6-diiminopyridinium iron, the cocatalyst was methylaluminoxane, the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)acenaphthene diimide nickel dibromide, and the polar olefin monomer was methyl acrylate. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at 140°C. The reactor was then cooled to 75°C under an ethylene atmosphere.

[0053] The experimental steps are as follows: add 900 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, then add 4000 μmol of co-catalyst and 18 μmol of polymerization catalyst to carry out polymerization reaction. When the reaction lasts for 6 minutes, stop the ethylene gas supply, add 12 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0054] Example 2

[0055] In this embodiment, the experimental conditions are the same as those in Example 1.

[0056] The experimental steps are as follows: add 900 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 4000 μmol of co-catalyst, add 18 μmol of polymerization catalyst to carry out polymerization reaction, add 270 μmol of copolymerization catalyst and 3 mol of polar olefin monomer when the reaction lasts for 6 minutes, continue the reaction for 30 minutes, stop ethylene gas supply, add 12 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0057] Example 3

[0058] In this example, the polymerization reaction temperature was 85°C, the polymerization pressure was 0.6 MPa, the solvent was toluene, the oligomerization catalyst was bis(β-diketone imine)benzyl zirconium, the cocatalyst was modified methylaluminoxane (MMAO-12, CAS: 206451-54-9), the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)acenaphthene diimide nickel dibromide, and the polar olefin monomer was methyl acrylate. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at 140°C. The reactor was then cooled to 85°C under an ethylene atmosphere.

[0059] The experimental steps are as follows: add 700 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 500 μmol of co-catalyst, add 5 μmol of polymerization catalyst to carry out polymerization reaction, stop the ethylene gas supply when the reaction lasts for 7 minutes, add 9 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0060] Example 4

[0061] In this embodiment, the experimental conditions are the same as those in Example 3.

[0062] The experimental steps are as follows: add 700 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 500 μmol of co-catalyst, add 5 μmol of polymerization catalyst to carry out polymerization reaction, add 60 μmol of copolymerization catalyst and 5 mol of polar olefin monomer when the reaction lasts for 7 minutes, continue the reaction for 18 minutes, stop ethylene gas supply, add 9 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0063] Example 5

[0064] In this example, the polymerization reaction temperature was 60°C, the polymerization reaction pressure was 0.9 MPa, the solvent was toluene, the oligomerization catalyst was 2,6-diiminopyridinium iron, the cocatalyst was modified methylaluminoxane (MMAO-3A, ​​CAS: 146905-79-5), the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)acenaphthene diimide nickel dibromide, and the polar olefin monomer was vinyl butyl ether. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at a high temperature of 140°C. After that, the reactor was cooled to 60°C under an ethylene atmosphere.

[0065] The experimental steps are as follows: add 840 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 4500 μmol of co-catalyst, add 15 μmol of polymerization catalyst to carry out polymerization reaction, stop the ethylene gas supply when the reaction lasts for 7 minutes, add 15 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0066] Example 6

[0067] In this embodiment, the experimental conditions are the same as those in Example 5.

[0068] The experimental steps are as follows: add 840 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 4500 μmol of co-catalyst, add 15 μmol of polymerization catalyst to carry out polymerization reaction, add 150 μmol of copolymerization catalyst and 4 mol of polar olefin monomer when the reaction lasts for 7 minutes, continue the reaction for 18 minutes, stop ethylene gas supply, add 15 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0069] Example 7

[0070] In this example, the polymerization reaction temperature was 80°C, the polymerization pressure was 0.75 MPa, the solvent was cyclohexane, the oligomerization catalyst was bis(β-diketone imine)benzyl zirconium, the cocatalyst was methylaluminoxane, the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)acenaphthene diimide nickel dibromide, and the polar olefin monomer was vinyl butyl ether. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at 140°C. The reactor was then cooled to 80°C under an ethylene atmosphere.

[0071] The experimental steps are as follows: add 800 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 3000 μmol of co-catalyst, add 10 μmol of polymerization catalyst to carry out polymerization reaction, stop the ethylene gas supply when the reaction lasts for 6 minutes, add 14 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0072] Example 8

[0073] In this embodiment, the experimental conditions are the same as those in Example 7.

[0074] The experimental steps are as follows: add 800 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 3000 μmol of co-catalyst, add 10 μmol of polymerization catalyst to carry out polymerization reaction, add 50 μmol of copolymerization catalyst and 5 mol of polar olefin monomer when the reaction lasts for 6 minutes, continue the reaction for 30 minutes, stop ethylene gas supply, add 14 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0075] Example 9

[0076] In this example, the polymerization reaction temperature was 70°C, the polymerization pressure was 0.56 MPa, the solvent was n-hexane, the oligomerization catalyst was bis(β-diketone imine)benzyl zirconium, the cocatalyst was modified methylaluminoxane (MMAO-7, CAS: 206451-54-9), the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)ethyleneacenaphthene diimide nickel dibromide, and the polar olefin monomer was allyl acetate. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at 140°C. The reactor was then cooled to 70°C under an ethylene atmosphere.

[0077] The experimental steps are as follows: add 700 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 450 μmol of co-catalyst, add 3 μmol of polymerization catalyst to carry out polymerization reaction, stop the ethylene gas supply when the reaction lasts for 6 minutes, add 4 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0078] Example 10

[0079] In this embodiment, the experimental conditions are the same as those in Example 9.

[0080] The experimental steps are as follows: add 700 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 450 μmol of co-catalyst, add 3 μmol of polymerization catalyst to carry out polymerization reaction, add 39 μmol of copolymerization catalyst and 3 mol of polar olefin monomer when the reaction lasts for 6 minutes, continue the reaction for 20 minutes, stop ethylene gas supply, add 4 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0081] Example 11

[0082] In this example, the polymerization reaction temperature was 90°C, the polymerization pressure was 0.7 MPa, the solvent was Isopar E, the oligomerization catalyst was bis(β-diketone imine)benzyl zirconium, the cocatalyst was methylaluminoxane, the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)ethyleneacenaphthene diimide nickel dibromide, and the polar olefin monomer was allyl acetate. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at 140°C. The reactor was then cooled to 90°C under an ethylene atmosphere.

[0083] The experimental steps are as follows: add 800 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 1600 μmol of co-catalyst, add 8 μmol of polymerization catalyst to carry out polymerization reaction, stop the ethylene gas supply when the reaction lasts for 8 minutes, add 10 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0084] Example 12

[0085] In this embodiment, the experimental conditions are the same as those in Example 11.

[0086] The experimental steps are as follows: add 800 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 1600 μmol of co-catalyst, add 8 μmol of polymerization catalyst to carry out polymerization reaction, add 72 μmol of copolymerization catalyst and 1.5 mol of polar olefin monomer when the reaction lasts for 8 minutes, continue the reaction for 25 minutes, stop ethylene gas supply, add 10 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0087] Example 13

[0088] In this example, the polymerization reaction temperature was 85°C, the polymerization pressure was 0.75 MPa, the solvent was Isopar E, the oligomerization catalyst was 2,6-diiminopyridinium iron, the cocatalyst was methylaluminoxane, the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)ethyleneacenaphthenediimidenickel dibromide, and the polar olefin monomer was methyl acrylate. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at 140°C. The reactor was then cooled to 85°C under an ethylene atmosphere.

[0089] The experimental steps are as follows: add 800 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 1800 μmol of co-catalyst, add 10 μmol of polymerization catalyst to carry out polymerization reaction, stop the ethylene gas supply when the reaction lasts for 8 minutes, add 8 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0090] Example 14

[0091] In this example, the experimental conditions are the same as those in Example 13.

[0092] The experimental steps are as follows: add 800 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 1800 μmol of co-catalyst, add 10 μmol of polymerization catalyst to carry out polymerization reaction, add 100 μmol of copolymerization catalyst and 1.8 mol of polar olefin monomer when the reaction lasts for 8 minutes, continue the reaction for 25 minutes, stop ethylene gas supply, add 8 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0093] Example 15

[0094] In this example, the polymerization reaction temperature was 75°C, the polymerization reaction pressure was 0.8 MPa, the solvent was n-hexane, the oligomerization catalyst was 2,6-diiminopyridinium iron, the cocatalyst was modified methylaluminoxane (MMAO-12, CAS: 206451-54-9), the copolymerization catalyst was N,N'-bis(2,6-diisopropylphenyl)ethyleneacenaphthenediimidenickel dibromide, and the polar olefin monomer was methyl acrylate. The polymerization experiment was conducted in a 1200 mL batch polymerization reactor. Prior to the experiment, the reactor was purged with nitrogen three times and ethylene three times at a high temperature of 140°C. After that, the reactor was cooled to 75°C under an ethylene atmosphere.

[0095] The experimental steps are as follows: add 850 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 450 μmol of co-catalyst, add 3 μmol of polymerization catalyst to carry out polymerization reaction, stop the ethylene gas supply when the reaction lasts for 6 minutes, add 6 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0096] Example 16

[0097] In this example, the experimental conditions are the same as those in Example 15.

[0098] The experimental steps are as follows: add 850 mL of anhydrous and oxygen-free solvent under ethylene atmosphere, start stirring at a stirring rate of 600 r / min, add 450 μmol of co-catalyst, add 3 μmol of polymerization catalyst to carry out polymerization reaction, add 39 μmol of copolymerization catalyst and 1.8 mol of polar olefin monomer when the reaction lasts for 6 minutes, continue the reaction for 20 minutes, stop ethylene gas supply, add 6 mL of acidified ethanol to terminate the polymerization, and collect the polymerization product.

[0099] The polymer products obtained in Examples 1 to 16 were analyzed using the following method:

[0100] In the present invention, the melting point (Tm) of the polymer is analyzed by differential scanning calorimetry (DSC). The analysis conditions are as follows: 8.0 to 10.0 mg of a polymer sample is heated to 220° C. at a rate of 10° C. / min, held constant for 5 minutes to eliminate thermal history, then cooled to -90° C. at a rate of 10° C. / min, held constant for 5 minutes, and then heated to 220° C. at a rate of 10° C. / min. The melting point (Tm) of the polymer is determined based on the second heating (melting) curve of the sample.

[0101] The molecular weight (Mn and Mw) and molecular weight distribution index (PDI = Mw / Mn) of the polymers were measured by gel permeation chromatography (GPC). The analysis conditions were as follows: the separation column was calibrated with monodisperse polystyrene standards, and the Mark-Houwink constant used was K = 1.21 × 10 -4 and α = 0.707, for the resulting polymer sample, K = 1.56 × 10 -4 and α = 0.76. The eluent was 1,2,4-trichlorobenzene, and the flow rate was 1.0 mL / min.

[0102] By NMR carbon spectroscopy ( 13 C-NMR analysis was performed to determine the terminal double bond content of crystalline, low molecular weight polyethylene (LMWPE) or the molar insertion of crystalline, low molecular weight polyethylene into the hyperbranched polyethylene backbone. Analysis conditions were as follows: a deuterated o-dichlorobenzene solution of the polymer (10% polymer mass fraction) was prepared at 150°C and stirred for 3-4 hours. The pulse angle was 90°, with reverse proton decoupling, a pulse delay of 3 seconds, and a collection time of 0.8 seconds. Approximately 5000 scans were performed for each sample.

[0103] Room-temperature tensile testing of polymers was performed using a universal testing machine. The following analysis conditions were used: polymer strips were compression molded at 180°C, quenched at room temperature, and cut to the desired shape and dimensions according to the GB / T 528-2009 test method. The tensile rate was 20 mm / min. Tensile testing was performed on at least five strips for each sample, and the average of the test results was used.

[0104] The analysis results are shown in Table 1 below:

[0105] Table 1

[0106]

[0107]

[0108] As can be seen from the data in Table 1, the polymer products of Examples 2, 4, 6, 8, 10, 12, 14, and 16 provided by the present invention (i.e., hyperbranched polyethylene polymers) have a weight average molecular weight of 25×10 4 ~45×10 4g / mol, a molecular weight distribution index of 2.0 to 5.0, a melting point (Tm) of 80 to 96°C, an elongation at break greater than 900%, and a breaking strength greater than 5 MPa. It possesses typical elastomer characteristics, and by introducing polar olefin monomers into the main chain, the hyperbranched polyethylene polymer has high polarity, which can greatly improve its compatibility with polar pigments, glass fibers, clay, metals and other substances, thereby improving the performance of the composite material.

[0109] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is to be construed in the widest manner consistent with the principles and novel features disclosed herein.

Claims

1. A hyperbranched polyethylene polymer, characterized in that Its side chain is polyethylene and its main chain is hyperbranched polyethylene; The hyperbranched polyethylene polymer is a terpolymer of ethylene, polyethylene and a polar olefin monomer; the molar insertion amount of polyethylene in the hyperbranched polyethylene polymer is 3 to 7.5%; the molar insertion amount of the polar olefin monomer in the hyperbranched polyethylene polymer is 1 to 4%; The molecular weight distribution index of the hyperbranched polyethylene polymer is 2.0 to 2.5; The polar vinyl monomer is selected from any one or more of methyl acrylate, vinyl butyl ether or allyl acetate; The hyperbranched polyethylene polymer is obtained according to the following preparation method: S1: mixing ethylene, a solvent, an oligomerization catalyst, and a co-catalyst and performing a homopolymerization reaction to obtain a reaction product containing polyethylene; S2: copolymerizing the reaction product obtained in step S1, ethylene, and a polar olefin monomer in the presence of a copolymerization catalyst to obtain a hyperbranched polyethylene polymer; The copolymerization catalyst is an α-diimine nickel catalyst.

2. The hyperbranched polyethylene polymer according to claim 1, wherein The melting point of the polyethylene in the side chain is 80-100°C, and the weight average molecular weight is 8.0×10 2 ~3.0×10 3 g / mol, the molecular weight distribution index is 1.0~3.0, and the chain end double bond content is greater than 85%.

3. The hyperbranched polyethylene polymer according to claim 1, wherein The weight average molecular weight of the hyperbranched polyethylene polymer is 25×10 4 ~45×10 4 g / mol.

4. A method for preparing a hyperbranched polyethylene polymer as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: S1: mixing ethylene, a solvent, an oligomerization catalyst, and a co-catalyst and performing a homopolymerization reaction to obtain a reaction product containing polyethylene; S2: copolymerizing the reaction product obtained in step S1, ethylene and a polar olefin monomer in the presence of a copolymerization catalyst to obtain a hyperbranched polyethylene polymer.

5. The preparation method according to claim 4, characterized in that The solvent is selected from any one or more of n-hexane, toluene, cyclohexane or isoparaffin; The oligomerization catalyst is a single-active-center post-metallocene catalyst, and the single-active-center post-metallocene catalyst is selected from bis(β-diketone imine)benzyl zirconium catalyst and / or 2,6-diiminopyridine iron catalyst; The co-catalyst is selected from methylaluminoxane compounds and / or modified methylaluminoxane compounds; The copolymerization catalyst is an α-diimine nickel catalyst, and the α-diimine nickel catalyst is selected from N, N ， -bis(2,6-diisopropylphenyl)acenaphthene diimide nickel dibromide catalyst and / or N,N ， -bis(2,6-diisopropylphenyl)ethyleneacenaphthenediimide nickel dibromide catalyst; The polar vinyl monomer is selected from any one or more of methyl acrylate, vinyl butyl ether or allyl acetate.

6. The preparation method according to claim 4, characterized in that The molar ratio of the co-catalyst to the oligomerization catalyst is (50-900):1; The molar ratio of ethylene to oligomerization catalyst is (1.4×10 6 ~1×10 7 ):1; The molar ratio of the copolymerization catalyst to the oligomerization catalyst is 20:1 to 1:1; The molar ratio of the polar olefin monomer to ethylene is (0.1-20):

1.

7. The preparation method according to claim 4, characterized in that The temperature of the homopolymerization reaction and the copolymerization reaction are independently 50-90° C., and the pressure is independently 0.1-1.0 MPa.

8. An adhesive, characterized in that: The invention comprises the hyperbranched polyethylene polymer according to any one of claims 1 to 3 or the hyperbranched polyethylene polymer prepared by the preparation method according to any one of claims 4 to 7.

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