Preparation method of polar polyolefin

Abstract

The invention provides a preparation method of polar polyolefin, and belongs to the technical field of polyolefin. The preparation method comprises the following steps: in an inert atmosphere, under the action of a catalyst and a cocatalyst, copolymerizing C2-C6 olefin and an alkylated polar monomer in an organic solvent to prepare polar polyolefin, wherein the alkylated polar monomer is prepared by the following steps: dissolving an alkylating reagent in an organic solvent, adding a polar monomer, and mixing and stirring to obtain the alkylated polar monomer; the polar monomer comprises at least one of halogenated alpha-olefin, alpha-olefine acid, alpha-enol, alpha-olefine aldehyde, alpha-olefine ester and alpha-olefine ketone. The polar monomer is pre-protected by adding the alkylating reagent, so that effective copolymerization of C2-C6 olefin and the polar monomer is realized, and the performance of polyolefin is favorably improved.

Description

Technical Field

[0001] This invention relates to the field of polyolefin technology, and more particularly to a method for preparing polar polyolefins. Background Technology

[0002] Polyolefins are a class of polymeric materials formed by the polymerization of olefin monomers (mainly α-olefins such as ethylene and propylene). They are among the most produced and widely used synthetic resins. Polyolefins possess excellent molding properties, heat resistance, and mechanical properties, making them widely used in plastic packaging, construction, medical, and electronics industries.

[0003] However, because polyolefin molecules do not contain polar groups, they exhibit poor interfacial adhesion with inorganic components such as glass fiber, carbon fiber, calcium carbonate, and polymers, resulting in poor compatibility. Therefore, it is difficult to utilize polyolefins by blending these materials. Summary of the Invention

[0004] In view of this, in order to at least partially solve the aforementioned technical problems, the present invention provides a method for preparing polar polyolefins.

[0005] According to one aspect of the present invention, a method for preparing a polar polyolefin is provided, comprising: copolymerizing a C2-C6 olefin with an alkylated polar monomer in an organic solvent under an inert atmosphere and in the presence of a catalyst and a co-catalyst to prepare a polar polyolefin;

[0006] Alkylated polar monomers are prepared by the following steps: dissolving an alkylating agent in an organic solvent, adding a polar monomer, and mixing and stirring to obtain alkylated polar monomers; the polar monomers include at least one of halogenated α-olefins, α-enoic acids, α-enols, α-enaldehydes, α-en esters, and α-enones.

[0007] Optionally, C2-C6 olefins include ethylene or propylene.

[0008] Optionally, the alkylating agent includes at least one of alkylaluminum, alkylsilane chloride, alkylmagnesium, and alkylboron.

[0009] Optionally, the organic solvent includes at least one of n-pentane, isopentane, neopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and toluene.

[0010] Optionally, when the C2-C6 olefin is ethylene, the alkylating agent is dissolved in the organic solvent at a temperature of -10 to 40°C, and the mixing and stirring time is 2 to 4 hours.

[0011] Optionally, when the C2-C6 olefin is propylene, the alkylating agent is dissolved in the organic solvent at a temperature of -50 to 10°C, and the mixing and stirring time is 2 to 3 hours.

[0012] Optionally, when the C2-C6 olefin is ethylene, the polar monomer includes at least one of halo-α-olefins, α-enoic acids, α-olefin esters, and α-enols; wherein, the α-enoic acid includes at least one of 7-octenic acid, 8-nonenoic acid, 9-decen-1-acid, and 10-undecenoic acid; preferably at least one of 9-decen-1-acid and 10-undecenoic acid; more preferably 10-undecenoic acid. The α-olefin ester includes at least one of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, methyl oleate, ethyl linoleate, and methyl 10-undecenoic acid; preferably at least one of butyl acrylate and methyl oleate; more preferably methyl oleate. α-Enols include at least one of 6-hepten-1-ol, 8-nonen-1-ol, 9-decen-1-ol, 10-undecenol, 8-nonen-1-ol, and 6-hepten-1-ol norbornenol; preferably at least one of 9-decen-1-ol and 10-undecenol; more preferably 9-decen-1-ol. Halogenated α-olefins include at least one of 4-chloro-1-butene, 5-chloro-1-pentene, and 6-bromo-1-hexene, preferably at least one of 5-chloro-1-pentene and 6-bromo-1-hexene; more preferably 6-bromo-1-hexene.

[0013] Optionally, when the C2-C6 olefin is propylene, the polar monomer includes at least one of α-enol, α-enal, α-enoic acid, and α-olefin ester; wherein, the α-enoic acid includes at least one of acrylic acid, methacrylic acid, 4-penten-1-ic acid, 5-hexen-1-ic acid, 6-hepten-1-ic acid, 7-octen-1-ic acid, 8-nonen-1-ic acid, 9-decen-1-ic acid, undecenoic acid, and dodecenoic acid; the α-enol includes allyl alcohol, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, 6- At least one of hepten-1-ol, 7-octen-1-ol, 8-nonen-1-ol, 9-decen-1-ol, undecenol, and dodecenol; α-olefin esters include at least one of methyl acrylate, diester, citrate, and methyl decenoate; organic aldehydes include at least one of 4-pentenal, 5-hexenal, 4-hexenal, 4-heptenal, and 4-isoheptenal; α-ketones include at least one of methyl allyl ketone, 1,6-heptadien-4-one, oct-1-en-4-one, and 4-methylpent-4-en-2-one.

[0014] Optionally, the alkylaluminum includes at least one of trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-butylaluminum, trihexylaluminum, diethylaluminum chloride, dimethylaluminum chloride, diethylaluminum chloride, dimethylaluminum chloride, sesquimethylaluminum, sesquiethylaluminum, aluminum hexafluoroacetylacetonate, and tri(hexafluoro-2,4-diketenyl)aluminum.

[0015] Optionally, the alkyl magnesium includes at least one of diethyl magnesium, diisopropyl magnesium, tert-butyl magnesium, tert-butyl magnesium chloride, diethyl magnesium chloride, diisopropyl magnesium chloride, and dodecyl magnesium bromide.

[0016] Optionally, the alkyl boron includes at least one of trimethylboron, triethylboron, diethylmethoxyborane, and tripropylboron.

[0017] Optionally, the chloroalkylsilane includes at least one of methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, ethyltrichlorosilane, and phenyltrichlorosilane.

[0018] Optionally, the catalyst is a nickel diimine catalyst or a Ziegler-Natta catalyst.

[0019] Optionally, the nickel diimine catalyst has the structure shown in formula (I) as follows: R1 and R2 are the same, R3 and R4 are the same, and R1 and R3 are different; R1 and R2 are selected from any one of isopropyl, 3-pentyl, and diphenylmethyl; R3 and R4 are selected from any one of hydrogen, methyl, and isopropyl; X is selected from halogen.

[0020] Formula (I).

[0021] Optionally, the Ziegler-Natta catalyst is magnesium chloride-titanium tetrachloride.

[0022] Optionally, when the catalyst is a Ziegler-Natta catalyst, the copolymerization temperature is 50~90℃ and the pressure is 0.1~5MPa.

[0023] Optionally, when the catalyst is a nickel diimine catalyst, the copolymerization temperature is 10~75℃ and the pressure is 1~10MPa.

[0024] Optionally, when the catalyst is a Ziegler-Natta catalyst, the co-catalyst includes at least one of triethylaluminum, triisobutylaluminum, trimethylaluminum, sesquimethylaluminum, sesquiethylaluminum, methylaluminoxane, ethylaluminoxane, isopropylaluminoxane, and isobutylaluminoxane, preferably triisobutylaluminum.

[0025] Optionally, when the catalyst is a nickel diimide catalyst, the co-catalyst includes at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, dichloroethylaluminum, sesquimethylaluminum, sesquiethylaluminum, methylaluminoxane, ethylaluminoxane, isopropylaluminoxane, and isobutylaluminoxane, preferably triisobutylaluminum.

[0026] Optionally, when the catalyst is a Ziegler-Natta catalyst, the molar ratio of aluminum in the co-catalyst to titanium and alkylation polar monomer in the catalyst is (40~1000):1:(40~1000).

[0027] Optionally, when the catalyst is a nickel diimide catalyst, the molar ratio of aluminum in the co-catalyst to nickel and alkylation polar monomer in the catalyst is (50~1000):1:(5~100).

[0028] Optionally, a chain transfer agent is also added during copolymerization; the chain transfer agent includes at least one of hydrogen, diethylmagnesium, diethylzinc, triethylboron, and sesquiethylaluminum, preferably hydrogen or sesquiethylaluminum; the molar ratio of chain transfer agent to catalyst is (10~200):1.

[0029] According to embodiments of the present invention, polar monomers are treated with alkylating agents to modify the polar functional groups of the polar monomers. The alkyl groups reduce the ability of the treated alkylated polar monomers to interact harmfully with the active center of the catalyst, thereby facilitating the smooth chain growth of C2-C6 olefins and achieving copolymerization of C2-C6 olefins with polar monomers. Polar groups are successfully introduced into the polyolefin backbone, thereby improving the performance of polyolefins. Attached Figure Description

[0030] Figure 1 A flowchart illustrating a method for preparing polar polyolefins according to an embodiment of the present invention is shown;

[0031] Figure 2 Polarized light microscope images of the polar polypropylene of Example 23 and the non-polar polypropylene of Comparative Example 3 are shown.

[0032] Figure 3 The infrared spectrum of polar polypropylene of Example 1 of the present invention is shown;

[0033] Figure 4 The carbon NMR spectrum of the polar polypropylene of Example 1 of the present invention is shown;

[0034] Figure 5 The 1H NMR spectrum of the polar polypropylene of Example 1 of the present invention is shown.

[0035] Figure 6 The 1H NMR spectrum of the polar polypropylene of Example 27 of the present invention is shown.

[0036] Figure 7 The water contact angle test diagrams of Embodiment 23 and Comparative Example 3 of the present invention are shown. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the invention.

[0038] Polyolefins have advantages such as abundant raw material sources, mature production processes, strong structural designability, and excellent comprehensive performance. However, polyolefins have poor compatibility with inorganic components, making it difficult to directly blend or laminate polyolefins with inorganic components for use, and making it difficult to achieve the functionalization of polyolefin materials.

[0039] To improve the compatibility of polyolefins with other materials, copolymerization of olefins and polar monomers is often carried out using catalysts. However, polar monomers can poison the catalyst.

[0040] In realizing the concept of this invention, it was discovered that by using alkylating agents to protect polar monomers, the poisoning effect of polar monomers on catalysts is weakened, and polar groups can be introduced into the polyolefin backbone to improve the performance of polyolefins.

[0041] Specifically, according to one embodiment of the present invention, a method for preparing a polar polyolefin is provided. Figure 1 A flowchart illustrating a method for preparing polar polyolefins according to an embodiment of the present invention is shown, as follows: Figure 1 As shown, the preparation method includes steps S101 to S102.

[0042] In step S101, the alkylating agent is dissolved in an organic solvent, and the polar monomer is added and mixed and stirred to obtain the alkylated polar monomer.

[0043] In step S102, under an inert atmosphere and with the aid of a catalyst and a co-catalyst, C2-C6 olefins and alkylated polar monomers are copolymerized in an organic solvent to prepare polar polyolefins.

[0044] According to embodiments of the present invention, the polar monomer includes at least one selected from halogenated α-olefins, α-olefinic acids, α-enols, α-enales, α-olefin esters, and α-enones. Before copolymerization, the polar monomer is protected using an alkylating agent because the active site of the catalyst is usually a low-valence transition metal, which is sensitive to the polar functional groups of the polar monomer. Heteroatoms in the polar functional groups, such as oxygen and nitrogen, can interact with the active site of the catalyst, causing the polar monomer to preferentially occupy the active site and preventing the insertion of C2-C6 olefins. The present invention utilizes the protection of the polar monomer with an alkylating agent, passivating the polar functional groups through alkylation, reducing the possibility of harmful interactions between the polar monomer and the active site of the catalyst. Therefore, under the action of the catalyst and co-catalyst, C2-C6 olefins can smoothly grow on the active site, preparing functional polyolefin materials containing alkylated polar groups, which helps to improve the performance of polyolefins.

[0045] In some embodiments, the C2-C6 olefins include ethylene. It is understood that polyethylene is typically homopolymerized from ethylene in related technologies, but its non-polar properties limit its application. The introduction of polar functional groups improves the adhesiveness, compatibility, and dyeability of polyethylene. Due to the protective effect of the alkylated polar monomers, the polar polyethylene of this invention has a higher polar monomer insertion ratio than polar polyethylene obtained by direct copolymerization using polar monomers, resulting in superior properties such as higher abrasion resistance, higher strength, and higher impact resistance. It also facilitates the acquisition of polar polyethylene with higher molecular weights. Especially during subsequent spinning, it exhibits lower elongation at break, higher strength, and higher modulus.

[0046] It should be noted that the viscosity-average molecular weight of the polar polyethylene of the present invention is 1×10⁻⁶. 6 ~5×10 6 g / mol.

[0047] In some embodiments, the C2-C6 olefins include propylene. It is understood that in related technologies, polypropylene is typically homopolymerized from propylene, which benefits from its good mechanical properties; however, its non-polar nature results in low surface energy and poor adhesion, limiting its application range. The introduction of polar functional groups improves the interfacial adhesion between polypropylene and inorganic components, resulting in composite materials with higher mechanical properties and a more stable structure, and improving its wettability to liquids, making the composite materials easier to print, coat, and bond. Due to the protective effect of alkylated polar monomers, the molecular chains of the polar polypropylene of this invention are arranged in an ordered manner, resulting in higher activity, enhanced tensile strength, impact resistance, and fatigue resistance, improved compatibility between polar polypropylene and other materials, and overcoming the limitations of polypropylene in related technologies.

[0048] In some embodiments, the alkylating agent includes at least one of alkylaluminum, alkylsilane chloride, alkylmagnesium, and alkylboron. As a Lewis acid, the alkylating agent can react with the active hydrogen or electronegative atom on the polar monomer, protecting the polar functional group. Based on the steric hindrance effect of the group in the alkylating agent, the ability of the alkylated polar monomer to have harmful interactions with the active center of the catalyst is reduced.

[0049] From the perspective of improving the solubility and cost of raw materials, the organic solvent includes at least one of n-pentane, isopentane, neopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and toluene, preferably at least one of n-hexane, methylcyclopentane, and n-heptane, and more preferably n-heptane.

[0050] In some embodiments, when the C2-C6 olefin is ethylene, the alkylating agent is dissolved in the organic solvent at a temperature of -10 to 40°C, and the mixing and stirring time is 2 to 4 hours. Ethylene has a symmetrical structure and a low electron cloud density, making it highly resistant to alkylating agents. Adjusting the dissolution temperature and mixing and stirring time within the above ranges minimizes the likelihood of side reactions.

[0051] Optionally, the temperature can be -10℃, 0℃, 10℃, 20℃, 30℃ or 40℃, and the stirring time can be, for example, 2h, 3h or 4h.

[0052] In some embodiments, when the C2-C6 olefin is propylene, the alkylating agent is dissolved in the organic solvent at a temperature of -50 to 10°C, and the mixing and stirring time is 2 to 3 hours. Propylene has an asymmetric structure, and the presence of methyl groups results in a high electron cloud density in the double bonds, which may lead to side reactions such as coordination. Therefore, it is necessary to set the temperature in a lower range.

[0053] Optionally, the temperature can be -50℃, -40℃, -30℃, -20℃, -10℃, 0℃ or 10℃, and the stirring time can be, for example, 2h, 2.5h or 3h.

[0054] In some embodiments, when the C2-C6 olefin is ethylene, the polar monomer includes at least one of halo-α-olefins, α-olefinic acids, α-olefinic esters, and α-enols. This arrangement helps to increase the insertion ratio between the polar monomer and ethylene, thereby improving the molecular weight and properties of polar polyethylene.

[0055] Optionally, the α-enoic acid includes at least one of 7-octenic acid, 8-nonenoic acid, 9-decen-1-acid, and 10-undecenoic acid, preferably at least one of 9-decen-1-acid and 10-undecenoic acid, and more preferably 10-undecenoic acid.

[0056] Optionally, the α-olefin ester includes at least one of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, methyl oleate, ethyl linoleate, and methyl 10-undecenoate, preferably at least one of butyl acrylate and methyl oleate, and more preferably methyl oleate.

[0057] Optionally, the α-enol includes at least one of 6-hepten-1-ol, 8-nonen-1-ol, 9-decen-1-ol, 10-undecenol, 8-nonen-1-ol, 6-hepten-1-ol norbornenol, preferably at least one of 9-decen-1-ol and 10-undecenol, more preferably 9-decen-1-ol.

[0058] Optionally, the halogenated α-olefin includes at least one of 4-chloro-1-butene, 5-chloro-1-pentene, and 6-bromo-1-hexene, preferably at least one of 5-chloro-1-pentene and 6-bromo-1-hexene, and more preferably 6-bromo-1-hexene.

[0059] In some embodiments, when the C2-C6 olefin is propylene, the polar monomer includes at least one of α-enol, α-enal, α-enoic acid, and α-olefin ester. This configuration helps to increase the insertion ratio between the polar monomer and propylene, which in turn helps to improve the interfacial adhesion between the polar polypropylene and the inorganic component, further enhancing the mechanical properties and structural stability of the composite material.

[0060] Optionally, the α-enoic acid includes at least one of acrylic acid, methacrylic acid, 4-penten-1-acid, 5-hexen-1-acid, 6-hepten-1-acid, 7-octen-1-acid, 8-nonen-1-acid, 9-decen-1-acid, undecenoic acid, and dodecenoic acid, preferably undecenoic acid.

[0061] Optionally, the α-enol includes at least one of allyl alcohol, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, 6-hepten-1-ol, 7-octen-1-ol, 8-nonen-1-ol, 9-decen-1-ol, undecenol, and dodecanol, preferably 9-decen-1-ol.

[0062] Optionally, the α-olefin ester includes at least one of methyl acrylate, diester, citrate, and methyl decenoate, preferably methyl decenoate.

[0063] Optionally, the organic aldehyde includes at least one of 4-pentenal, 5-hexenal, 4-heptenal, 4-heptenal, and 4-isoheptenal, preferably 4-heptenal.

[0064] Optionally, the α-enone includes at least one of methyl allyl ketone, 1,6-heptadien-4-one, oct-1-en-4-one, and 4-methylpent-4-en-2-one, preferably methyl allyl ketone.

[0065] In some embodiments, the catalyst is a nickel diimide catalyst or a Ziegler-Natta catalyst. Using these two catalysts can further promote the copolymerization reaction between polar monomers and polyolefins, thereby improving the properties of polar polyolefins, such as creep resistance, adhesion properties, and dyeing properties. Specifically, using a pre-transition metal catalyst (Ziegler-Natta catalyst) can prepare polar polyolefins with different melt indices and different polar monomer insertion rates. Using nickel diimide catalysts with different skeletons can achieve homopolymerization or copolymerization of ethylene, propylene, and polar monomers.

[0066] In some embodiments, if the nickel diimine catalyst is not supported, the resulting reaction product (polar polyolefin) may form on the reactor wall, making it difficult to achieve sufficient collection of the reaction product. The present invention, by using the aforementioned alkylated polar monomer in conjunction with a nickel diimine catalyst or a Ziegler-Natta catalyst, allows the prepared reaction product to be linked to the α-polar monomer and the alkylating agent, thereby reducing adhesion.

[0067] Furthermore, the nickel diimine catalyst has the structure shown in formula (I) or (II) as follows: R1 is the same as R2, R3 is the same as R4, and R1 is different from R3; R1 and R2 are both selected from isopropyl, 3-pentyl, and diphenylmethyl; R3 and R4 are both selected from hydrogen, methyl, and isopropyl; X is selected from halogen; R5 is the same as R6, R7 is the same as R8, and R5 is different from R6; R5 and R6 are both selected from isopropyl, 3-pentyl, and diphenylmethyl; R7 and R8 are both selected from hydrogen, methyl, and isopropyl; X1 and X2 are independently selected from halogen, such as F, Cl, Br, and I.

[0068] Formula (I);

[0069] Equation (II).

[0070] It should be noted that the nickel diimine catalyst needs to be dissolved in a first organic solvent before use. The first organic solvent includes at least one of toluene, dichloromethane, tetrahydrofuran, dimethyl sulfoxide, and N,N-dimethylformamide, preferably toluene. The selection of the first organic solvent is mainly based on its ability to fully dissolve the nickel diimine catalyst.

[0071] Furthermore, the Ziegler-Natta catalyst is magnesium chloride-titanium tetrachloride. It should be noted that the Ziegler-Natta catalyst needs to be dissolved in a second organic solvent before use. The second organic solvent includes at least one selected from n-pentane, isopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and toluene, preferably at least one selected from n-hexane, methylcyclopentane, and n-heptane, and more preferably n-heptane. The selection of the second organic solvent is primarily based on its ability to fully dissolve the Ziegler-Natta catalyst.

[0072] In some embodiments, the alkylaluminum includes at least one of trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-butylaluminum, trihexylaluminum, diethylaluminum chloride, dimethylaluminum chloride, diethylaluminum chloride, dimethylaluminum chloride, sesquimethylaluminum, sesquiethylaluminum, aluminum hexafluoroacetylacetonate, and tris(hexafluoro-2,4-diketenyl)aluminum.

[0073] In some embodiments, the alkylaluminum includes at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, dichloroethylaluminum, sesquimethylaluminum, sesquiethylaluminum, methylaluminoxane, ethylaluminoxane, isopropylaluminoxane, and isobutylaluminoxane, preferably triisobutylaluminum.

[0074] In some embodiments, the alkyl magnesium includes at least one of diethyl magnesium, diisopropyl magnesium, tert-butyl magnesium, tert-butyl magnesium chloride, diethyl magnesium chloride, diisopropyl magnesium chloride, and dodecyl magnesium bromide, preferably tert-butyl magnesium.

[0075] In some embodiments, the alkylboron includes at least one of trimethylboron, triethylboron, diethylmethoxyborane, and tripropylboron, preferably triethylboron.

[0076] In some embodiments, the chloroalkylsilane includes at least one of methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, ethyltrichlorosilane, and phenyltrichlorosilane.

[0077] In some embodiments, during the copolymerization of ethylene, when the catalyst is a Ziegler-Natta catalyst, the copolymerization temperature is 50–90°C and the pressure is 0.1–5 MPa. Optionally, the copolymerization temperature can be 50°C, 60°C, 70°C, 80°C, or 90°C, and the pressure can be 0.1 MPa, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 3 MPa, 4 MPa, or 5 MPa.

[0078] In some embodiments, during the copolymerization of ethylene with alkylated polar monomers, when the catalyst is a nickel diimide catalyst, the copolymerization temperature is 10~75°C and the pressure is 1~10 MPa. Optionally, the copolymerization temperature can be 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C or 75°C, and the pressure can be 1 MPa, 2 MPa, 4 MPa, 6 MPa, 8 MPa or 10 MPa.

[0079] In some embodiments, during the copolymerization of propylene with the alkylated polar monomer, when the catalyst is a Ziegler-Natta catalyst, the copolymerization temperature is 25–90°C and the pressure is 1–4.0 MPa. Optionally, the copolymerization temperature can be 25°C, 50°C, 70°C, or 90°C, and the pressure can be 1 MPa, 2 MPa, 3 MPa, or 4 MPa.

[0080] In some embodiments, during the copolymerization of propylene with the alkylated polar monomer, when the catalyst is a nickel diimide catalyst, the copolymerization temperature is 20–60°C and the pressure is 0.5–3.5 MPa. Optionally, the copolymerization temperature can be 20°C, 30°C, 40°C, 50°C, or 60°C, and the pressure can be 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, or 3.5 MPa.

[0081] It is understandable that the copolymerization of ethylene and alkylated polar monomers is carried out by slurry polymerization. The specific process can be as follows: an organic solvent is injected into the reactor and replaced with nitrogen and ethylene in that order 3-5 times. Under a slightly positive nitrogen pressure, alkylaluminum is first injected into the reactor to remove impurities. After stirring for 5-10 minutes, the catalyst and co-catalyst are injected into the reactor and stirred. Then, ethylene and alkylated polar monomers are added to carry out the polymerization reaction.

[0082] It can be understood that the copolymerization of propylene and alkylated polar monomers undergoes precipitation polymerization under the catalysis of nickel diimide catalyst. The specific process can be as follows: the solvent is pumped into the reactor, the air in the reactor is replaced with nitrogen, and then propylene from the propylene cylinder is introduced into the reactor using a booster pump. The prepared cleaning agent (alkylaluminum), alkylated polar monomer, catalyst, co-catalyst, and optional chain transfer agent are sequentially pumped into the reactor using a diaphragm pump to carry out the polymerization reaction.

[0083] It can be understood that the copolymerization of propylene and alkylated polar monomers undergoes bulk polymerization under the catalysis of Ziegler-Natta catalysts. The specific process can be as follows: the air in the reaction vessel is replaced with nitrogen, and then the pressure in the reaction vessel is increased to 4.0 MPa using a booster pump. Subsequently, the prepared purge agent (alkylaluminum), alkylated polar monomers, catalyst, and co-catalyst are sequentially pumped into the vessel using a diaphragm pump to carry out the polymerization reaction.

[0084] In some embodiments, when the catalyst is a Ziegler-Natta catalyst, the co-catalyst includes at least one selected from triethylaluminum, triisobutylaluminum, trimethylaluminum, sesquimethylaluminum, sesquiethylaluminum, methylaluminoxane, ethylaluminoxane, isopropylaluminoxane, and isobutylaluminoxane, preferably triisobutylaluminum. This arrangement better facilitates the copolymerization reaction, resulting in better performance of the polar polyolefin.

[0085] In some embodiments, when the catalyst is a nickel diimide catalyst, the co-catalyst includes at least one selected from trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, dichloroethylaluminum, sesquimethylaluminum, sesquiethylaluminum, methylaluminoxane, ethylaluminoxane, isopropylaluminoxane, and isobutylaluminoxane, preferably triisobutylaluminum. This configuration better facilitates the copolymerization reaction, resulting in improved properties of the polar polyolefin.

[0086] In some embodiments, when the catalyst is a Ziegler-Natta catalyst, the molar ratio of aluminum in the co-catalyst to titanium and alkylating polar monomers in the catalyst is (40~1000):1:(40~1000), more preferably (200~400):1:(40~200). This setting helps to promote the smooth progress of the copolymerization reaction.

[0087] In some embodiments, when the catalyst is a nickel diimide catalyst, the molar ratio of aluminum in the co-catalyst to nickel in the catalyst and the alkylating polar monomer is (50~1000):1:(5~100), preferably (100~500):1:(10~50). This setting helps to promote the smooth progress of the copolymerization reaction.

[0088] In some embodiments, a chain transfer agent is also added during copolymerization. Adding a chain transfer agent during the polymerization of polar polyolefins helps to adjust the molecular weight and molecular weight distribution of the polar polymer as needed. In particular, adding a chain transfer agent during the polymerization of polar polypropylene allows for more precise adjustment of the melt index of polar polypropylene, thus adapting it to the needs of different application scenarios.

[0089] It is understandable that in the preparation of polar polypropylene, chain transfer agents can not only effectively adjust the molecular weight, but also be regarded as regulators of the melt index.

[0090] In some embodiments, the chain transfer agent includes at least one selected from hydrogen, diethylmagnesium, diethylzinc, triethylboron, and sesquiethylaluminum, preferably at least one selected from hydrogen and sesquiethylaluminum. The aforementioned chain transfer agents can assist in controlling the performance parameters of polar polyolefins, such as more precisely controlling the molecular weight of polar polyethylene and the melt index of polar polypropylene, which helps in subsequent adaptation to different application areas.

[0091] In some implementations, the molar ratio of chain transfer agent to catalyst is (10~200):1. This setting avoids waste of chain transfer agent while achieving a more precise control effect.

[0092] Based on this, the process of preparing polar polyethylene in this invention reduces the poisoning of transition metal atoms of the catalyst by protecting the polar monomers, and achieves controllable molecular weight of polar polyethylene by adjusting the molecular weight through chain transfer agents. Subsequent spinning and processing performance tests prove that the polar polyethylene of this invention has superior strength, elongation at break and modulus compared with the prior art.

[0093] Meanwhile, the introduction of polar functional groups into alkylated polar monomers improves the adhesion, compatibility, and dyeability of polyethylene, making it suitable for producing novel polyethylene composite functional materials. Direct copolymerization of higher molecular weight polyethylene with polar monomers is a good approach to obtaining polar polyethylene. However, this approach suffers from a "low polar monomer insertion rate problem." Because Lewis basic polar functional groups poison the transition metal centers of Lewis acidic catalysts and may produce side reactions that lead to catalyst deactivation, the method of this invention reduces the poisoning of the catalyst by polar monomers, and the resulting high molecular weight polar polyethylene is industrially feasible.

[0094] Similarly, the process for preparing polar polypropylene in this invention reduces the poisoning of transition metal atoms of the catalyst by protecting the polar monomers, and the introduction of polar functional groups in the alkylated polar monomers significantly improves the interfacial adhesion between polypropylene and inorganic components. This results in polypropylene composite materials with higher mechanical properties and a more stable structure, and increases the surface energy of polar polypropylene, improving its wettability to liquids such as water and inks, making the polypropylene composite materials easier to print, coat, and bond.

[0095] Furthermore, adjusting the melt flow index is a crucial step in the production and processing of polar polypropylene, significantly impacting its performance and applications. This invention controls the melt flow index of polar polypropylene by precisely adjusting the amount of chain transfer agent added, preparing polar polypropylene resins with different melt flow indices to meet the needs of various application scenarios. These resins have wide applications in industries such as engine parts, electronic components, medical devices, medical packaging, film materials, and material toughening and reinforcement. Thus, based on the protection of polar monomers and the addition of chain transfer agents, the prepared polar polypropylene possesses advantages in interfacial adhesion, wettability, biocompatibility, barrier properties, dielectric properties, antistatic properties, and environmental friendliness and recyclability. These advantages give polar polypropylene broad application prospects and market potential across multiple industries.

[0096] The present invention will be further illustrated below through embodiments and their results. In the following detailed description, numerous specific details are set forth for ease of explanation to provide a comprehensive understanding of the embodiments of the present invention. However, it will be apparent that one or more embodiments may be practiced without these specific details. Moreover, the details in the following embodiments can be arbitrarily combined to form other feasible embodiments without conflict.

[0097] It should be noted that the specific embodiments described below are merely illustrative examples, and the scope of protection of this invention is not limited thereto. The raw materials used in the following embodiments are commercially available or prepared using recognized processing methods. The catalysts used in the polymerization process are all self-made catalysts from Hefei Zhongke Kele New Materials Co., Ltd.

[0098] Example 1:

[0099] The preparation process of polar polypropylene (catalyzed by nickel diimine catalyst) includes the following steps:

[0100] 1. Preparation of alkylated polar monomers:

[0101] Under a nitrogen atmosphere, 7 mL of triethylaluminum was added to 63 mL of heptane solvent at -30 °C while stirring continuously for 2 hours. Then, 30 mL of undecenol was added dropwise while stirring continuously. After the addition was complete, the mixture was stirred continuously for 2 hours to prepare a 0.5 mol / L alkylated polar monomer.

[0102] 2. Preparation of the catalyst composition:

[0103] 10 mg of nickel diimine catalyst (as shown in the formula below) prepared by Hefei Zhongke Kele New Materials Co., Ltd. was dissolved in 5 mL of dichloromethane, and 10 mL of diethylaluminum monochlorocolate co-catalyst was added to prepare the catalyst composition for later use.

[0104]

[0105] 3. Copolymerization reaction:

[0106] Precipitation polymerization was performed using a polymerization process. 1.6 L of heptane was pumped into a 2.5 L reactor, and the air in the reactor was replaced with nitrogen three times. Propylene from a propylene cylinder was then pumped into the reactor using a booster pump. 3 mL of triethylaluminum, the previously prepared catalyst composition, and 5 mL of diethylzinc as a chain transfer agent were added into the reactor. The temperature was set at 45 °C, the pressure at 1.0 MPa, and the reaction time at 1 h to prepare polar polypropylene.

[0107] Example 2:

[0108] The preparation process of Example 2 is largely the same as that of Example 1, except that undecenol is replaced with methyl allyl ketone and the chain transfer agent is replaced with diethylmagnesium to prepare polar polypropylene.

[0109] Example 3:

[0110] The preparation process of Example 3 is largely the same as that of Example 1, except that undecenol is replaced with 4-heptenal and the chain transfer agent is replaced with ethyl magnesium chloride, thus obtaining polar polypropylene.

[0111] Example 4:

[0112] The preparation process of Example 4 is largely the same as that of Example 1, except that undecenol is changed to 10-undecenic acid and the chain transfer agent is changed to diethylzinc to prepare polar polypropylene.

[0113] Example 5:

[0114] The preparation process of Example 5 is largely the same as that of Example 1, except that the amount of undecenol is adjusted to 9 mL to prepare polar polypropylene.

[0115] Example 6:

[0116] The preparation process of Example 6 is largely the same as that of Example 1, except that the chain transfer agent is diethylzinc, the dosage is 5 mL, and the alkylating agent is diethylaluminum chloride, the dosage is 3 mL.

[0117] Example 7:

[0118] The preparation process of Example 7 is largely the same as that of Example 6, except that the amount of diethylaluminum chloride added is adjusted to 5 mL.

[0119] Example 8:

[0120] The preparation process of Example 8 is largely the same as that of Example 6, except that the amount of diethylaluminum chloride added is adjusted to 7 mL.

[0121] Example 9:

[0122] The preparation process of Example 9 is largely the same as that of Example 6, except that the amount of diethylzinc added is adjusted to 3 mL.

[0123] Example 10:

[0124] The preparation process of Example 10 is largely the same as that of Example 6, except that the amount of diethylzinc added is adjusted to 1 mL.

[0125] Comparative Example 1: The preparation process of Comparative Example 1 is largely the same as that of Example 6. Polar polypropylene was prepared using a catalyst with the following formula, without the addition of a chain transfer agent.

[0126]

[0127] Figure 3 The infrared spectrum of polar polypropylene of Example 1 of the present invention is shown; Figure 4 The carbon NMR spectrum of the polar polypropylene of Example 1 of the present invention is shown; Figure 5 The hydrogen nuclear magnetic resonance spectrum of the polar polypropylene of Example 1 of the present invention is shown. Figures 3-5 As shown, polar polypropylene can be prepared by the method of the present invention.

[0128] Further performance tests were conducted on the polar polypropylene prepared in Examples 1-10 and Comparative Example 1. Detailed results are shown in Table 1. The polar monomer insertion ratio was calculated using the peak area from the proton NMR spectrum (e.g., ...). Figure 5 As shown, there are two values: 2.00 on the left represents the peak area of ​​polar groups, and 176.16 on the right represents the peak area of ​​nonpolar groups. The characteristic peak area is directly proportional to the number of hydrogen atoms.

[0129] Table 1

[0130]

[0131] As can be seen from Examples 6 to 10, increasing the amount of alkylating agent increases the polarity insertion ratio, while the activity and molecular weight decrease accordingly. Chain transfer agents, on the other hand, can adjust the molecular weight and melt index of the product. Therefore, by selecting appropriate amounts of alkylating agent and chain transfer agent according to different product requirements, different products can be obtained.

[0132] Comparing Examples 5 and 1 in Table 1, it can be seen that adding too much chain transfer agent results in a significant decrease in viscosity-average molecular weight and a high melt index. The molecular weight and melt index can be adjusted based on different needs by varying the amount of chain transfer agent added, thus adapting to the requirements of different scenarios. Comparing the results of Examples 1-10 and Comparative Example 1, it can be seen that without adding chain transfer agent, the viscosity-average molecular weight is relatively high, but the melt index is low, making it difficult to promote widespread application.

[0133] The viscosity-average molecular weight was measured using an IVS-800 fully automated viscometer for a specific product. A dilute solution of the product was prepared using decahydronaphthalene as a solvent, and the viscosity of the solution was measured and converted to the viscosity-average molecular weight using a formula.

[0134] The melt flow index was measured using a melt flow rate tester using the mass method (MFR) according to the national standard GB / T 3682.1-2018 "Determination of melt mass flow rate and melt volume flow rate of plastics - Part 1: Standard method".

[0135] Example 11:

[0136] 1. Preparation of alkylated polar monomers:

[0137] Under a nitrogen atmosphere, 4.9 g of triethylboron was added to 64.3 mL of heptane solvent at -20 °C while stirring, and the mixture was stirred at a constant temperature for 2 hours. Then, 30 mL of undecenoic acid was added dropwise while stirring, and the mixture was stirred at a constant temperature for 2 hours after the addition was complete, to prepare a 0.5 mol / L alkylated polar monomer.

[0138] 2. The catalyst composition is prepared as shown in the following formula:

[0139]

[0140] 5 mg of nickel diimide catalyst prepared by Hefei Zhongkele New Materials Co., Ltd. was dissolved in 5 mL of dichloromethane, and 10 mL of diethylaluminum monochlorocolate co-catalyst was added to prepare the catalyst composition for later use.

[0141] The alkylating agent used was triethylboron.

[0142] 3. Polymerization reaction:

[0143] The polymerization process was precipitation polymerization. 1.6 L of heptane solvent was injected into the reactor, and the air in the reactor was replaced with nitrogen three times. Propylene from a propylene cylinder was then introduced into the reactor using a booster pump. 3 mL of triethylboron, a catalyst composition, and 5 mL of diethylzinc as a chain transfer agent were added to the reactor. The temperature was set at 45 °C, the pressure at 1.50 MPa, and the reaction time at 1 h, yielding polar polypropylene.

[0144] Example 12:

[0145] The preparation process of Example 12 is largely the same as that of Example 11, except that undecenol is replaced with methyl allyl ketone to prepare polar polypropylene.

[0146] Example 13:

[0147] The preparation process of Example 13 is largely the same as that of Example 11, except that undecenol is replaced with 4-heptenal to prepare polar polypropylene.

[0148] Example 14:

[0149] The preparation process of Example 14 is largely the same as that of Example 11, except that undecenol is changed to 10-undecenol and the chain transfer agent is changed to diethylzinc to prepare polar polypropylene.

[0150] Example 15:

[0151] The preparation process of Example 15 is largely the same as that of Example 11, except that the amount of undecenol is adjusted to 9 mL to prepare polar polypropylene.

[0152] Comparative Example 2:

[0153] The preparation process of Comparative Example 2 is largely the same as that of Example 11, except that no chain transfer agent is added, and polar polypropylene is prepared.

[0154] The polar polypropylene prepared in Examples 11 to 15 and Comparative Example 2 was further tested for performance. The specific results are shown in Table 2.

[0155] Table 2

[0156]

[0157] Comparing Examples 15 and 11 in Table 2, it can be seen that adding too much chain transfer agent results in a significant decrease in viscosity-average molecular weight and a high melt index. The molecular weight and melt index can be adjusted based on different needs by varying the amount of chain transfer agent added, thus adapting to the requirements of different scenarios. Comparing the results of Examples 11-15 and Comparative Example 2, it can be seen that without adding chain transfer agent, the viscosity-average molecular weight is relatively high, but the melt index is low, making it difficult to promote widespread application.

[0158] Example 16:

[0159] The preparation process of polar polypropylene (under the catalysis of Ziegler-Natta catalyst) includes the following steps:

[0160] 1. Preparation of alkylated polar monomers:

[0161] Under a nitrogen atmosphere, 9.9 g (11.7 mL) of triisobutylaluminum was added to 58.3 mL of heptane solvent at -40 °C while stirring continuously for 2 hours. Then, 30 mL of undecenoic acid was added dropwise while stirring continuously. After the addition was complete, the mixture was stirred continuously for 2 hours to prepare a 0.5 mol / L alkylated polar monomer.

[0162] 2. Preparation of the catalyst composition:

[0163] The catalyst used was magnesium chloride-titanium tetrachloride prepared by Hefei Zhongkele New Materials Co., Ltd. or 30 mg of commercially available magnesium chloride-titanium tetrachloride, dissolved in 5 mL of heptane, with 0.56 mL of triethylaluminum co-catalyst added. The catalyst composition was then prepared for use.

[0164] 3. Copolymerization reaction;

[0165] The polymerization process was precipitation polymerization. 1.6 L of heptane solvent was pumped into the reactor, and the reactor was purged three times with nitrogen. Propylene from a propylene cylinder was then introduced into the reactor. 3 mL of alkylating polar monomer, the previously prepared catalyst composition, and H2 at 0.1 MPa pressure were pumped into the reactor as a chain transfer agent using a diaphragm pump. The temperature was set at 75 °C, the pressure at 3.0 MPa, and the reaction time at 30 min, yielding polar polypropylene.

[0166] Example 17:

[0167] The preparation process of Example 17 is largely the same as that of Example 16, except that the pressure of hydrogen gas used is adjusted to 0.2 MPa.

[0168] Example 18:

[0169] The preparation process of Example 18 is largely the same as that of Example 16, except that the pressure of hydrogen gas is adjusted to 0.4 MPa.

[0170] Example 19:

[0171] The preparation process of Example 19 is largely the same as that of Example 16, except that the pressure of hydrogen gas is adjusted to 0.6 MPa.

[0172] Example 20:

[0173] The preparation process of Example 20 is largely the same as that of Example 18, except that commercial Ziegler-Natta catalyst 1# is used, which is a commercial third-generation Ziegler-Natta catalyst. Its composition includes a co-catalyst, a main catalyst (TiCl4-MgCl2), and an internal electron donor. The co-catalyst is mainly triethylaluminum, and the internal electron donor is mainly benzoate.

[0174] Example 21:

[0175] The preparation process of Example 21 is largely the same as that of Example 18, except that commercial Ziegler-Natta catalyst 2# is used, which is a commercial fourth-generation Ziegler-Natta catalyst. Its main composition is the same as that of the third generation, but there are slight differences in the support, internal electron donor, and external electron donor. Phthalate is used as the internal electron donor, and DPDMS (diphenyl dimethoxysilane) is used as the external electron donor.

[0176] The polar polypropylene prepared in Examples 16 to 21 was further tested for performance, and the specific results are shown in Table 3.

[0177] Table 3

[0178]

[0179] Comparing Examples 16 to 21, it can be found that after adjusting the hydrogen pressure, the melt index increases with the increase of hydrogen partial pressure, while the molecular weight decreases. This indicates that by adjusting the hydrogen partial pressure, the rate of polymer chain transfer to hydrogen can be controlled, thereby indirectly adjusting the melt index, proving that the melt index of polar polyolefins prepared by this method is controllable.

[0180] Example 22:

[0181] The preparation process of polar polypropylene (under the catalysis of Ziegler-Natta catalyst) includes the following steps:

[0182] 1. Preparation of alkylated polar monomers:

[0183] Under a nitrogen atmosphere, 3.3 g of triisobutylaluminum was added to 66.1 mL of heptane solvent at -40 °C while stirring, and the mixture was stirred at a constant temperature for 2 hours. Then, 30 mL of undecenoic acid was added dropwise while stirring, and the mixture was stirred at a constant temperature for 2 hours after the addition was complete, to prepare a 0.5 mol / L alkylated polar monomer.

[0184] 2. Preparation of the catalyst composition:

[0185] The catalyst used was magnesium chloride-titanium tetrachloride prepared by Hefei Zhongkele New Materials Co., Ltd. or 30 mg of commercially available magnesium chloride-titanium tetrachloride, dissolved in 5 mL of heptane, with 0.56 mL of triethylaluminum co-catalyst added. The catalyst composition was then prepared for use.

[0186] 3. Copolymerization reaction;

[0187] The polymerization process was precipitation polymerization. 1.6 L of heptane solvent was introduced into the reactor, and the reactor was purged with nitrogen. Propylene from a propylene cylinder was then introduced into the reactor. 3 mL of the previously prepared alkylated polar monomer, the previously prepared catalyst composition, and H2 at 0.4 MPa pressure were pumped into the reactor as a chain transfer agent using a diaphragm pump. The temperature was set at 75 °C, the pressure at 3.5 MPa, and the reaction time at 1 h, yielding polar polypropylene.

[0188] Example 23:

[0189] The preparation process of Example 23 is largely the same as that of Example 22, except that the amount of alkylated polar monomer added is adjusted to 6 mL.

[0190] Example 24:

[0191] The preparation process of Example 24 is largely the same as that of Example 22, except that the amount of alkylated polar monomer added is adjusted to 9 mL.

[0192] Comparative Example 3:

[0193] The preparation process of Comparative Example 3 is largely the same as that of Example 22, except that no alkylating polar monomer is added to prepare polypropylene.

[0194] Comparative Example 4:

[0195] The preparation process of Comparative Example 4 is largely the same as that of Example 22, except that a polar monomer that has not undergone alkylation protection (i.e., undecenoic acid is added directly) is added to prepare polypropylene.

[0196] Figure 2 Polarizing microscope images of the polar polypropylene of Example 23 and the non-polar polypropylene of Comparative Example 3 are shown; wherein, a is a polarizing microscope image of Comparative Example 3, and b is a polarizing microscope image of Example 23. Figure 2 As shown in a~b, it can be seen that in a on the left, the molecules are isotropic, and the physical properties (such as refractive index) are consistent in different directions. They have no birefringence effect on polarized light and are always dark. In b on the right, the molecules have inherent dipole moments or ordered structural arrangements (such as crystals and oriented polymers). The physical properties (such as refractive index) in different directions are significantly different, which will cause birefringence and interference of polarized light and create a bright field, proving the insertion of polar monomers.

[0197] Figure 7 The diagrams show water contact angle test results for Embodiment 23 and Comparative Example 3 of the present invention, where a is the water contact angle test result for Embodiment 23; and b is the water contact angle test result for Comparative Example 3. Figure 7As shown in a~b, polar groups can be copolymerized into polyethylene, giving polar polyethylene better wetting properties and hydrophilicity, and further improving compatibility.

[0198] The polypropylene prepared in Examples 22-24 and Comparative Examples 3-4 was further tested for performance. The specific results are shown in Table 4.

[0199] Table 4

[0200]

[0201] Comparing Example 22 and Comparative Example 3 in Table 4, it can be seen that without the addition of alkylated polar monomers, polypropylene cannot be inserted into polar monomers, making it difficult to promote its application. Comparative Example 4 shows that unprotected polar monomers will poison the Ziegler-Natta catalyst, resulting in reduced activity.

[0202] Application Example 1:

[0203] Polypropylene of type Z30s (41% by mass), polypropylene of type K8003 (35% by mass), polar polyolefin prepared in Example 1 (4% by mass), and polypropylene of type 508A (20% by mass) were mixed together and granulated using a twin-screw extruder at 210°C, followed by underwater pelletizing. The granulated material was then injection molded to obtain the composite material. The comprehensive mechanical properties of the composite material were tested, and the specific properties are shown in Table 5 below.

[0204] Application Comparative Example 1:

[0205] The preparation process of Comparative Example 1 is largely the same as that of Application Example 1, except that the polar polypropylene is replaced with maleic anhydride modified polypropylene to obtain a composite material. The comprehensive mechanical properties of the composite material are tested, and the specific properties are shown in Table 5 below.

[0206] Table 5

[0207]

[0208] The comparison between Application Example 1 and Application Comparative Example 1 shows that the protection of alkylated polar monomers and the insertion of polar monomers in polar polypropylene significantly enhance and toughen the mechanical properties of the composite material.

[0209] Example 25:

[0210] The preparation process of polar polyethylene (catalyzed by nickel diimine catalyst) includes the following steps:

[0211] 1. Preparation of alkylated polar monomers:

[0212] Under a nitrogen atmosphere, 18.38 mL of triethylaluminum was added to 71.52 mL of heptane solvent at -30 to -20 °C while stirring. After freezing, 10.1 mL of 10-undecenoic acid was added dropwise. After the addition was complete, the reaction was carried out for 2-3 h to prepare 0.5 M alkylated 10-undecenoic acid.

[0213] 2. Preparation of the catalyst composition:

[0214] The following formula was used: 10 mg of diimine nickel catalyst prepared by Hefei Zhongkele New Materials Co., Ltd. was dissolved in 5 mL of toluene, and 10 mL of diethylaluminum monochloro co-catalyst was added to prepare the catalyst composition for later use.

[0215]

[0216] 3. Copolymerization reaction:

[0217] The polymerization process was slurry polymerization. 1L of heptane was added to a 2.5L polymerization reactor. The air in the reactor was successively purged three times using nitrogen and ethylene vacuum. Diethylaluminum chloride (a purge agent) was injected into the reactor using a syringe and stirred for 10 minutes. Then, the catalyst composition was injected into the reactor and stirred for 2 minutes, followed by the introduction of ethylene. The temperature was set to 70℃, the pressure to 2.0MPa, and the time to 1 hour, yielding polar polyethylene.

[0218] Example 26:

[0219]

[0220] The preparation process of Example 26 is largely the same as that of Example 25, except that the catalyst and alkylated polar monomer are replaced as described above. The process is as follows: Under a nitrogen atmosphere, 18.38 mL of triethylaluminum and 73.94 mL of heptane solvent are continuously stirred at -30 to -20 °C. After freezing, 7.68 mL of 7-octenic acid is added dropwise. After the addition is complete, the reaction is carried out for 2-3 hours to prepare 0.5 M alkylated 7-octenic acid, which is then used to prepare polar polyethylene.

[0221] Example 27:

[0222]

[0223] The preparation process of Example 27 is largely the same as that of Example 25, except that the catalyst and alkylated polar monomer are replaced as described above. The process is as follows: Under a nitrogen atmosphere, 18.38 mL of triethylaluminum and 72.22 mL of heptane solvent are continuously stirred at -30 to -20 °C. After freezing, 9.4 mL of 10-undecenol is added dropwise. After the addition is complete, the reaction is carried out for 2-3 hours to prepare 0.5 M alkylated 10-undecenol, which is then used to prepare polar polyethylene.

[0224] Figure 6 The 1H NMR spectrum of the polar polypropylene of Example 27 of the present invention is shown. Figure 6 As shown, it can be confirmed that polar polyethylene was prepared.

[0225] Example 28:

[0226]

[0227] The preparation process of Example 28 is largely the same as that of Example 25, except that the catalyst and alkylating polar monomer are replaced as described above. The process is as follows: Under a nitrogen atmosphere, 18.38 mL of triethylaluminum and 73.12 mL of heptane solvent are continuously stirred at -30 to -20 °C. After freezing, 8.5 mL of 8-nonen-1-ol is added dropwise. After the addition is complete, the reaction is carried out for 2-3 hours to prepare 0.5 M alkylated 8-nonen-1-ol, which is then used to prepare polar polyethylene.

[0228] Example 29:

[0229] The preparation process of Example 29 is largely the same as that of Example 25, except for the preparation process of the alkylated polar monomer: under a nitrogen atmosphere, 18.38 mL of triethylaluminum and 74.42 mL of heptane solvent are continuously stirred at -30 to -20 °C. After freezing, 7.2 mL of 6-hepten-1-ol is added dropwise. After the addition is complete, the reaction is carried out for 2-3 hours to prepare 0.5 M alkylated 6-hepten-1-ol, which is then used to prepare polar polyethylene.

[0230] The polar polyethylene prepared in Examples 25 to 29 was further tested for performance, and the specific results are shown in Table 6.

[0231] Table 6

[0232]

[0233] Examples 30-39:

[0234] The alkylated polar monomers used in Examples 30-39 were prepared in the same manner as those in Examples 20-24. The amount of alkylated polar monomer used in Examples 30-39 was 6 mL, the copolymerization temperature was 70 °C, the pressure was 2.0 MPa, the reaction time was 30 min, the ethylene flow rate was 1000 mL / min, and the amount of catalyst used was 10 mg. The properties of the obtained polar polyethylene are shown in Table 7 below.

[0235] Table 7

[0236]

[0237] As shown in Table 6, the copolymerization of the alkylated polar monomers of this invention with ethylene yields polar polyethylene with high polar insertion ratios and high molecular weights. As shown in Table 7, the addition of chain transfer agents helps to alter the steric hindrance and electron cloud density of the catalyst's transition metal centers, making the molecular weight of polyethylene controllable.

[0238] Example 40:

[0239] The preparation process of polar polyethylene (under the catalysis of Ziegler-Natta catalyst) includes the following steps:

[0240] The preparation process of the alkylated polar monomer in Example 40 is the same as that in Example 27.

[0241] Preparation of the catalyst composition:

[0242] The catalyst used was magnesium chloride-titanium tetrachloride prepared by Hefei Zhongkele New Materials Co., Ltd. or 50 mg of commercially available magnesium chloride-titanium tetrachloride, which was dissolved in heptane solvent. 13.6 mL of triethylaluminum was used to control Al / Ti=400 to prepare the catalyst composition.

[0243] Copolymerization reaction:

[0244] The co-catalyst, catalyst, and polar monomer were added to heptane solvent at a dosage ratio of Al:Ti:Co of 400:1:20. The mixture was then introduced into ethylene for polymerization at a temperature of 50~90℃ and a pressure of 0.1~5MPa. After polymerization, the mixture was dried.

[0245] Examples 41-45:

[0246] The preparation process of Examples 41 to 45 is the same as that of Example 40, except that the alkylated polar monomer is replaced. The specific replacement materials are shown in Table 8 below.

[0247] Table 8

[0248]

[0249] Examples 46-55:

[0250] The alkylated polar monomers used in Examples 46 to 55 were prepared in the same manner as those in Examples 20 to 24. The amount of alkylated polar monomer used in Examples 46 to 55 was 6 mL, the copolymerization temperature was 70 °C, the pressure was 2.0 MPa, the reaction time was 30 min, the ethylene flow rate was 1000 mL / min, the amount of catalyst was 50 mg, and the amount of chain transfer agent was 5 mL. The properties of the obtained polar polyethylene are shown in Table 9 below.

[0251] Table 9

[0252]

[0253] As shown in Table 8, the alkylation-modified polar monomers of this invention, when copolymerized with ethylene, all achieve polar polyethylene with high polarity insertion ratio and high molecular weight. As shown in Table 9, the addition of chain transfer agents helps to change the steric hindrance and electron cloud density of the catalyst transition metal center, making the molecular weight of polyethylene controllable.

[0254] Application Example 2:

[0255] Spinning tests were conducted on the aforementioned polar high molecular weight polyethylene. The spinning process is as follows: The polar polyethylene prepared in Example 47 and white oil were mixed to obtain a high molecular weight polyethylene spinning mother liquor. The high molecular weight polyethylene spinning mother liquor was added to the feed port of a twin-screw extruder through a loss-of-weight feeding device. After being dissolved by the twin-screw extruder and quantitatively extruded by a metering pump, the filaments were stretched through the spinneret and the air gap section of the spinneret, and then collected in a coagulation bath to obtain nascent gel filaments. The spinneret has a multi-stage guide hole structure with 3 to 5 stages of progressively smaller diameters, and spinneret capillaries. The diameter of the first-stage guide hole is 5 to 20 mm with an aspect ratio of 2 to 5. The diameter of the next-stage guide hole is 0.3 to 0.6 times that of the previous stage, with an aspect ratio of 2 to 5. The diameter of the multi-stage guide holes decreases progressively. The diameter of the spinneret capillaries is 0.4 to 1.0 mm with an aspect ratio of 6 to 12. The obtained nascent gel filaments are extracted, dried, stretched by hot rollers, and then wound to obtain high molecular weight polyethylene fibers, which are then subjected to performance testing.

[0256] Compare application examples 2 to 4:

[0257] Commercially available polyethylene fibers were used, with models U090, 951 and LL-694 respectively.

[0258] The test performance of Application Example 2 and Comparative Application Examples 2 to 4 is shown in Table 10 below, where fineness can be understood as the weight in grams of 9000 meters of yarn or fiber.

[0259] Table 10

[0260]

[0261] The data in Table 10 show that the fiber in Application Example 2 has higher strength. Compared with the high-strength resin prepared by related technologies, the resin in Application Example 2 has lower elongation at break, higher modulus, and higher strength. This indicates that the high molecular weight polyethylene fiber produced by this invention has better performance than the high-strength resin prepared by related technologies.

[0262] Therefore, by alkylating polar monomers, they are made easier to copolymerize with ethylene and possess high activity. Compared with related technologies, this invention only changes the polar monomer and uses a specific catalyst for compatibility, thereby reducing the poisoning of the transition metal center of the catalyst by the polar monomer. Furthermore, by adding a chain transfer agent, the molecular weight of high molecular weight polyethylene is controlled. Through spinning and processing performance tests, it is demonstrated that the high molecular weight polyethylene fiber produced by this invention has superior strength, elongation at break, and modulus compared to the high-strength resin prepared by related technologies, while significantly reducing costs and meeting application requirements.

[0263] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a polar polyolefin, comprising: In an inert atmosphere, with the aid of a catalyst and a co-catalyst, C2-C6 olefins and alkylated polar monomers are copolymerized in an organic solvent to prepare polar polyolefins. The alkylated polar monomer is prepared through the following steps: The alkylating agent is dissolved in an organic solvent, and a polar monomer is added and mixed and stirred to obtain the alkylated polar monomer. The polar monomer includes at least one of halogenated α-olefins, α-enoic acids, α-enols, α-enaldehydes, α-en esters, and α-enones.

2. The preparation method according to claim 1, wherein, The C2-C6 olefins include ethylene or propylene; The alkylating agent includes at least one of alkylaluminum, alkylsilane chloride, alkylmagnesium, and alkylboron; The organic solvent includes at least one of n-pentane, isopentane, neopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and toluene.

3. The preparation method according to claim 2, wherein, When the C2-C6 olefin is ethylene, the alkylating agent is dissolved in the organic solvent at a temperature of -10 to 40°C, and the mixing and stirring time is 2 to 4 hours. When the C2-C6 olefin is propylene, the alkylating agent is dissolved in the organic solvent at a temperature of -50 to 10°C, and the mixing and stirring time is 2 to 3 hours.

4. The preparation method according to claim 2, wherein, When the C2-C6 olefin is ethylene, the polar monomer includes at least one of halo-α-olefin, α-enoic acid, α-olefin ester, and α-enol; wherein the α-enoic acid includes at least one of 7-octenic acid, 8-nonenoic acid, 9-decen-1-ic acid, and 10-undecenic acid; the α-olefin ester includes at least one of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, methyl oleate, ethyl linoleate, and methyl 10-undecenic acid; the α-enol includes at least one of 6-hepten-1-ol, 8-nonen-1-ol, 9-decen-1-ol, 10-undecenol, 8-nonen-1-ol, and 6-hepten-1-ol norbornenol; the halo-α-olefin includes at least one of 4-chloro-1-butene, 5-chloro-1-pentene, and 6-bromo-1-hexene; or, When the C2-C6 olefin is propylene, the polar monomer includes at least one selected from α-enol, α-enal, α-enoic acid, and α-olefin ester; wherein the α-enoic acid includes at least one selected from acrylic acid, methacrylic acid, 4-penten-1-acid, 5-hexen-1-acid, 6-hepten-1-acid, 7-octen-1-acid, 8-nonen-1-acid, 9-decen-1-acid, undecenoic acid, and dodecenoic acid; and the α-enol includes allyl alcohol, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, and 6-hepten-1-ol. The α-olefin comprises at least one of the following: en-1-ol, 7-octen-1-ol, 8-nonen-1-ol, 9-decen-1-ol, undecenol, and dodecanol; the α-olefin ester comprises at least one of methyl acrylate, diester, citrate, and methyl decenoate; the organic aldehyde comprises at least one of 4-pentenal, 5-hexenal, 4-hexenal, 4-heptenal, and 4-isoheptenal; and the α-olefin ketone comprises at least one of methyl allyl ketone, 1,6-heptadien-4-one, oct-1-en-4-one, and 4-methylpent-4-en-2-one.

5. The preparation method according to claim 2, wherein, The alkylaluminum comprises at least one of trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-butylaluminum, trihexylaluminum, diethylaluminum chloride, dimethylaluminum chloride, diethylaluminum chloride, dimethylaluminum chloride, sesquimethylaluminum, sesquiethylaluminum, aluminum hexafluoroacetylacetonate, and tris(hexafluoro-2,4-diketenyl)aluminum. The alkyl magnesium includes at least one of diethyl magnesium, diisopropyl magnesium, tert-butyl magnesium, tert-butyl magnesium chloride, diethyl magnesium chloride, diisopropyl magnesium chloride, and dodecyl magnesium bromide. The alkylboron includes at least one of trimethylboron, triethylboron, diethylmethoxyborane, and tripropylboron; The chloroalkylsilane includes at least one of methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, ethyltrichlorosilane, and phenyltrichlorosilane.

6. The preparation method according to claim 2, wherein, The catalyst is a nickel diimine catalyst or a Ziegler-Natta catalyst; The diimine nickel catalyst has the structure shown in formula (I): Formula (I); Among them, R1 and R2 are the same, R3 and R4 are the same, and R1 and R3 are different; R1 and R2 are both selected from isopropyl, 3-pentyl, and diphenylmethyl; R3 and R4 are both selected from hydrogen, methyl, and isopropyl. X is selected from halogens; The Ziegler-Natta catalyst is magnesium chloride-titanium tetrachloride.

7. The preparation method according to claim 6, wherein, When the catalyst is a Ziegler-Natta catalyst, the copolymerization temperature is 50~90℃ and the pressure is 0.1~5MPa; When the catalyst is a nickel diimine catalyst, the copolymerization temperature is 10~75℃ and the pressure is 1~10MPa.

8. The preparation method according to claim 6, wherein, When the catalyst is a Ziegler-Natta catalyst, the co-catalyst includes at least one of triethylaluminum, triisobutylaluminum, trimethylaluminum, sesquimethylaluminum, sesquiethylaluminum, methylaluminoxane, ethylaluminoxane, isopropylaluminoxane, and isobutylaluminoxane. When the catalyst is a nickel diimide catalyst, the co-catalyst includes at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, dichloroethylaluminum, sesquimethylaluminum, sesquiethylaluminum, methylaluminoxane, ethylaluminoxane, isopropylaluminoxane, and isobutylaluminoxane.

9. The preparation method according to claim 8, wherein, When the catalyst is a Ziegler-Natta catalyst, the molar ratio of aluminum in the co-catalyst to titanium and alkylating polar monomer in the catalyst is (40~1000):1:(40~1000). When the catalyst is a nickel diimide catalyst, the molar ratio of aluminum in the co-catalyst to nickel and alkylation polar monomer in the catalyst is (50~1000):1:(5~100).

10. The preparation method according to claim 6, wherein, In the copolymerization process, a chain transfer agent is also added; The chain transfer agent includes at least one of hydrogen, diethylmagnesium, diethylzinc, triethylboron, and sesquiethylaluminum; The molar ratio of the chain transfer agent to the catalyst is (10~200):1.

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