4-methyl-1-pentene homopolymer and process for its preparation and use

Abstract

The application relates to the field of high polymer materials, and discloses a 4-methyl-1-pentene homopolymer as well as a preparation method and application thereof. The isotacticity of the 4-methyl-1-pentene homopolymer is greater than or equal to 98%, the flexural modulus is greater than 1100 MPa, and the tensile modulus is greater than 1500 MPa. The 4-methyl-1-pentene homopolymer has the advantages of high isotacticity and good rigidity.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, specifically to a 4-methyl-1-pentene homopolymer, its preparation method, and its applications. Background Technology

[0002] PMP is a polymer of 4-methyl-1-pentene (4M1P), a novel polyolefin material. Due to its unique structural characteristics, PMP has a helical molecular chain and large side chains, resulting in loose packing. Its density is the lowest among all thermoplastic resins. Furthermore, the light transmittance of PMP resin does not change with processing conditions or product thickness, making it suitable for transparent products.

[0003] It can also withstand ethylene oxide and radiation sterilization treatment, and has outstanding electrical insulation, heat resistance, easy peeling, air permeability and transparency. It can be used in medical, home appliances, food packaging, leather release film, microporous membrane, lighting and optical equipment, etc., and is a functional resin that can create high value-added products.

[0004] CN101687946A discloses a method for manufacturing 4-methyl-1-pentene copolymers. The method includes: continuously feeding 4-methyl-1-pentene, at least one olefin selected from olefins with 2 to 20 carbon atoms other than 4-methyl-1-pentene, an organic solvent, and a polymerization catalyst containing a transition metal catalyst component and a co-catalyst component into a polymerization reactor; controlling the average residence time to be 0.1 to 10 hours; and simultaneously continuously extracting a polymerization reaction mixture from the polymerization reactor, the polymerization reaction mixture containing the generated 4-methyl-1-pentene copolymer having the following characteristics: the amount of solvent-soluble copolymer is controlled to be less than 15% by mass; and it contains 50 to 99.9% by mass structural units derived from 4-methyl-1-pentene. The copolymer prepared by this method has excellent heat resistance and rigidity. However, the copolymer provided by this invention suffers from low rigidity and low isotacticity.

[0005] Therefore, a 4-methyl-1-pentene homopolymer with high rigidity and high isotacticity is still needed for production. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of low isotacticity and low rigidity of 4-methyl-1-pentene homopolymer in the prior art.

[0007] To achieve the above objectives, a first aspect of the present invention provides a 4-methyl-1-pentene homopolymer having an isotacticity ≥98%, a flexural modulus >1100 MPa, and a tensile modulus >1500 MPa.

[0008] A second aspect of the present invention provides a method for preparing the 4-methyl-1-pentene homopolymer described in the first aspect, the method comprising: polymerizing a 4-methyl-1-pentene monomer in the presence of an organic solvent I, a catalyst, an external electron donor and hydrogen, under closed conditions; wherein the catalyst is a non-cerocadorogenous transition metal catalyst and an organoaluminum compound in a weight ratio of 1:0.1-2.

[0009] A third aspect of the invention provides the use of the 4-methyl-1-pentene homopolymer described in the first aspect in plastic articles.

[0010] The present invention has at least the following advantages:

[0011] The 4-methyl-1-pentene homopolymer prepared by the method of the present invention has the advantages of high isotacticity and good rigidity. Attached Figure Description

[0012] Figure 1 The C of the 4-methyl-1-pentene homopolymer prepared in Example 1 13 Nuclear magnetic resonance (NMR) spectrum. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] In this invention, the molecular weight distribution coefficient = weight-average molecular weight / number-average molecular weight.

[0015] As previously described, a first aspect of the present invention provides a 4-methyl-1-pentene homopolymer having an isotacticity ≥98%, a flexural modulus >1100 MPa, and a tensile modulus >1500 MPa.

[0016] Preferably, the density of the 4-methyl-1-pentene homopolymer is 0.832-0.833 g / cm³. 3 Its melting point is 220-240℃.

[0017] Preferably, at a temperature of 260°C, the melt mass flow rate at a load of 5 kg is 0.1-500 g / 10 min.

[0018] More preferably, the isotacticity of the 4-methyl-1-pentene homopolymer is ≥98%, and the melt mass flow rate at a load of 5 kg under a temperature of 260°C is 15-250 g / 10 min.

[0019] Preferably, the weight-average molecular weight of the 4-methyl-1-pentene homopolymer is 10,000 to 700,000, and the molecular weight distribution coefficient is 2 to 10.

[0020] More preferably, the weight-average molecular weight of the 4-methyl-1-pentene homopolymer is 200,000-600,000, and the molecular weight distribution coefficient is 2-10.

[0021] As previously stated, a second aspect of the present invention provides a method for preparing the 4-methyl-1-pentene homopolymer described in the first aspect, the method comprising: polymerizing a 4-methyl-1-pentene monomer in the presence of an organic solvent I, a catalyst, an external electron donor and hydrogen, under closed conditions; wherein the catalyst is a non-cerocadorogenous transition metal catalyst and an organoaluminum compound in a weight ratio of 1:0.1-2.

[0022] Preferably, the catalyst is a non-ceramic transition metal catalyst and an organoaluminum compound in a weight ratio of 1:0.5-2. The inventors of this invention have discovered that, under these preferred conditions, the 4-methyl-1-pentene homopolymer prepared by this method exhibits superior rigidity and higher isotacticity.

[0023] Preferably, the non-ceramic transition metal catalyst is a titanium metal catalyst, and the organoaluminum compound is a triethylaluminum compound.

[0024] Preferably, the organic solvent I is selected from at least one of aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons. More preferably, the organic solvent I is an aliphatic hydrocarbon.

[0025] In a preferred embodiment, the aliphatic hydrocarbon is C5-C. 18 Aliphatic hydrocarbons. Particularly preferred, the aliphatic hydrocarbons are C6-C6. 10 Aliphatic hydrocarbons.

[0026] More preferably, the aliphatic hydrocarbon is selected from at least one of n-hexane, n-heptane, n-octane, n-nonane, and n-decane.

[0027] Preferably, the alicyclic hydrocarbon is selected from at least one of cyclopentane, methylcyclopentane, cyclohexane, and cyclooctane.

[0028] Preferably, the aromatic hydrocarbon is selected from at least one of benzene, toluene, and xylene.

[0029] Preferably, the hydrogen gas is continuously introduced into a sealed environment. More preferably, the gas pressure of the introduced hydrogen is 0.01-0.3 MPa, and the diameter of the pipe through which the hydrogen gas is introduced is 2-3 mm. The inventors of this invention have discovered that, under these preferred conditions, the 4-methyl-1-pentene homopolymer prepared by this method exhibits superior rigidity and higher isotacticity.

[0030] Preferably, the preparation method of the non-ceramic transition metal catalyst includes:

[0031] (1) Under a protective atmosphere, organic solvent II and MgCl2 are subjected to a first heating treatment to obtain mixed solution I;

[0032] (2) The mixed solution I is subjected to a second heating treatment with an acid anhydride to obtain mixture I;

[0033] (3) The mixture I, lipids, and non-ceramic transition metal chloride I are subjected to a third heat treatment to obtain mixture II;

[0034] (4) The mixture II is subjected to a fourth heating treatment with non-ceramic transition metal chloride II to obtain the non-ceramic transition metal catalyst;

[0035] The non-cyclic transition metal chloride I and the non-cyclic transition metal chloride II are of the same type.

[0036] Preferably, the weight ratio of MgCl2 to the acid anhydride is 1:0.1-10.

[0037] More preferably, the weight ratio of MgCl2 to the acid anhydride is 1:0.1-1. The inventors of this invention have discovered that, under these preferred conditions, the 4-methyl-1-pentene homopolymer prepared by this method exhibits superior rigidity and higher isotacticity.

[0038] Preferably, the acid anhydride is selected from at least one of phthalic anhydride, triphthalic anhydride, and terephthalic anhydride.

[0039] Preferably, in step (3), the weight ratio of the mixture I, the ester substance and the non-ceramic transition metal chloride I is 1:0.01-1:0.01-20.

[0040] More preferably, the weight ratio of the mixture I, the ester, and the non-ceramic transition metal chloride I is 1:0.01-0.1:15-20. The inventors of this invention have discovered that, under these preferred conditions, the 4-methyl-1-pentene homopolymer prepared by this method exhibits superior rigidity and higher isotacticity.

[0041] Preferably, the ester is selected from at least one of diisooctyl phthalate, ethyl benzoate, dibutyl phthalate, succinate, glycol ester, catechol ester and phosphate ester.

[0042] In a preferred embodiment, the non-ceramic transition metal chloride I is selected from at least one of titanium tetrachloride and titanium trichloride.

[0043] Preferably, the weight ratio of the non-ceramic transition metal chloride I to the non-ceramic transition metal chloride II is 1:0.5-1.

[0044] Preferably, in step (1), the amount of MgCl2 used is 0.01-10g relative to 1mL of organic solvent II.

[0045] More preferably, the amount of MgCl2 used is 0.2-0.5 per 1 mL of organic solvent II.

[0046] Preferably, in step (1), the organic solvent II is C6-C. 20 A combination of alkanes and alcohols, or the organic solvent II being C6-C. 20 A combination of alkanes and aromatic compounds.

[0047] More preferably, the organic solvent II is n-octanol and n-decane in a weight ratio of 1:0.1-15, or the organic solvent II is toluene and n-decane in a weight ratio of 1:0.1-15.

[0048] Preferably, in step (1), the conditions for the first heat treatment include: a temperature of 120-150°C and a time of 1-3 hours.

[0049] Preferably, in step (2), the conditions for the second heat treatment include: a temperature of 120-150°C and a time of 1-3 hours.

[0050] Preferably, in step (3), the conditions for the third heating treatment include: a temperature of 100-120°C and a time of 1-4 hours.

[0051] Preferably, in step (4), the conditions for the fourth heat treatment include: a temperature of 100-120°C and a time of 1-4 hours.

[0052] It should be noted that each of the steps (1), (2), (3) and (4) in this invention is carried out independently in the presence of a protective atmosphere.

[0053] According to a particularly preferred embodiment, the conditions for the first heat treatment include: a temperature of 120-150°C and a time of 1-3 hours; the conditions for the second heat treatment include: a temperature of 120-150°C and a time of 1-3 hours; the conditions for the third heat treatment include: a temperature of 100-120°C and a time of 1-4 hours; and the conditions for the fourth heat treatment include: a temperature of 100-120°C and a time of 1-4 hours. The inventors of this invention have found that, under these preferred conditions, the 4-methyl-1-pentene homopolymer prepared by this method exhibits superior rigidity and higher isotacticity.

[0054] Preferably, the conditions for the polymerization reaction include: a temperature of 20-85°C and a time of 1-4 hours.

[0055] More preferably, the polymerization reaction is carried out at a temperature of 40-70°C.

[0056] Preferably, the external electron donor is selected from at least one of cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, and diisobutyldimethoxysilane.

[0057] Preferably, the amount of catalyst used is 0.1-0.4 mg relative to 1 mL of the 4-methyl-1-pentene monomer.

[0058] Preferably, the amount of the external electron donor is 0.01-0.2 mg relative to 1 mg of the catalyst.

[0059] More preferably, the amount of the external electron donor is 0.05-0.2 mg relative to 1 mg of the catalyst.

[0060] According to a preferred embodiment, the polymerization reaction described in this invention is carried out using a slurry polymerization process. The inventors of this invention have discovered that, under these preferred conditions, the 4-methyl-1-pentene homopolymer prepared by this method exhibits superior rigidity and higher isotacticity.

[0061] The slurry polymerization process described in this invention refers to using 4-methyl-1-pentene monomer as raw material, organic solvent as diluent, and utilizing a high-efficiency catalyst and external electron donor to carry out polymerization in the presence of hydrogen. The polymerized material is then separated, dried, mixed, and granulated to obtain 4-methyl-1-pentene homopolymer.

[0062] Preferably, the polymerization reaction of the present invention is carried out in a ring-shaped polymerization reactor or a stirred tank polymerization reactor.

[0063] According to a preferred embodiment, the 4-methyl-1-pentene monomer is continuously added from the bottom of the reactor.

[0064] According to a preferred embodiment, the hydrogen gas is introduced into the reaction system in an intermittent or continuous manner.

[0065] This invention does not impose any particular requirements on the heat removal method of the reactor; those skilled in the art can select one based on known techniques. For example, sensible heat removal or latent heat removal can be employed.

[0066] The present invention does not impose any particular restrictions on the method of extracting the material generated after the polymerization reaction from the reactor. Those skilled in the art can choose according to the technical means known in the art. For example, an inert gas pressurized ejection method or a pump extraction method can be used.

[0067] The preparation method of the aforementioned 4-methyl-1-pentene homopolymer of the present invention may also include conventional post-processing methods known in the art. The present invention does not impose particular requirements on the specific post-processing methods; for example, steps such as filtration, washing, and drying, which are conventionally known in the art, can be used. These will not be described in detail here, and those skilled in the art should not construe this as a limitation of the present invention.

[0068] As previously stated, a third aspect of the present invention provides the use of the 4-methyl-1-pentene homopolymer described in the first aspect in plastic articles.

[0069] In the following examples, unless otherwise specified, all raw materials are commercially available products.

[0070] The bulk polymerization method and the slurry polymerization method use the same polymerization reactor.

[0071] The isostatistic is calculated using C... 13 NMR is used to scan the sample, and (total area of ​​unidirectional 4-methyl-1-pentene structural units / total area) × 100% = isotacticity.

[0072] The calculation method is referenced in: JMS-REV.MACROMOL.CHEM.PHYS.,C32(3&4),301-406(1992).

[0073] Cat2 (non-ceramic transition metal catalyst): BCZ catalyst, model: BCZ, purchased from Sinopec Catalyst Co., Ltd.

[0074] Cat3: Metallocene SMC catalyst, model: SMC, purchased from Sinopec Catalyst Co., Ltd.

[0075] The slurry polymerization reactor, model N-5, was purchased from Beijing Xiandali Petrochemical Technology & Trade Co., Ltd.

[0076] Preparation Example

[0077] S1: Under nitrogen protection, organic solvent II and MgCl2 are subjected to a first heating treatment to obtain mixed solution I; the conditions of the first heating treatment include: temperature of 130℃ and time of 1.5h;

[0078] The amount of organic solvent II used is 12.5 mL, and the amount of MgCl2 used is 5 g (relative to 1 mL of organic solvent II, the amount of MgCl2 used is 0.4 g); the organic solvent II is a mixture of n-octanol and n-decane in a weight ratio of 1:10.

[0079] S2: Under nitrogen protection, the mixed solution I and phthalic anhydride are subjected to a second heat treatment to obtain mixture I; the conditions of the second heat treatment include: temperature of 130°C and time of 1 hour;

[0080] The amount of phthalic anhydride used is 3.5g (the weight ratio of MgCl2 to phthalic anhydride is 1:0.7);

[0081] S3: Under nitrogen protection, the mixture I, diisooctyl phthalate and TiCl4 are subjected to a third heat treatment to obtain mixture II; the conditions of the third heat treatment include: temperature of 110°C and time of 2 hours.

[0082] (The weight ratio of the mixture I, the diisooctyl phthalate, and the TiCl4 is 1:0.02:20)

[0083] S4: Under nitrogen protection, the mixture II and an equal weight of TiCl4 from step S3 are subjected to a fourth heating treatment; the conditions of the fourth heating treatment include: temperature of 110°C, time of 1 h, thorough washing of the reaction material with n-hexane, vacuum drying at -0.1 MPa and 25°C for 20 min to obtain a transition metal compound (named Cat1).

[0084] Example 1

[0085] In a closed environment, in the presence of organic solvent I, catalyst, diisobutyldimethoxysilane (external electron donor) and hydrogen, the monomer material is introduced into a stirred tank polymerization reactor to carry out a polymerization reaction, and the reacted material is obtained. The material is then expelled under pressure with nitrogen, filtered and dried to obtain 4-methyl-1-pentene homopolymer (named Z1).

[0086] The monomer is 400 mL of 4-methyl-1-pentene monomer; the organic solvent I is 2 L of n-hexane; the hydrogen gas pressure is 0.01 MPa, and the diameter of the pipe through which the hydrogen gas is introduced is 2 mm; the catalyst is a combination of the aforementioned Cat1 (30 mg) and triethylaluminum compound, and the mass ratio of Cat1 to the triethylaluminum compound is 1:1; the amount of diisobutyldimethoxysilane used is 3 mg.

[0087] The polymerization reaction was carried out under the following conditions: temperature 50°C and time 3.5 h.

[0088] Example 2

[0089] This embodiment uses a similar process to Example 1, except that the polymerization temperature is adjusted to 55°C; the rest is the same as in Example 1. The 4-methyl-1-pentene homopolymer prepared by this method is named Z2.

[0090] Example 3

[0091] The polymerization temperature was adjusted to 60°C, and the hydrogen gas pressure was 0.3 MPa; all other parameters were the same as in Example 1. The 4-methyl-1-pentene homopolymer prepared by this method was named Z3.

[0092] Example 4

[0093] This embodiment follows a similar process to Example 1, except that Cat1 is replaced with an equal mass of Cat2; all other aspects are the same as in Example 1. The 4-methyl-1-pentene homopolymer prepared by this method is named Z4.

[0094] Comparative Example 1

[0095] This embodiment uses a similar process to Example 1, except that hydrogen gas is not introduced during the polymerization reaction. Everything else is the same as in Example 1. The 4-methyl-1-pentene homopolymer prepared by this method is named DZ1.

[0096] Comparative Example 2

[0097] This comparative example follows a similar procedure to Example 1, except that no external electron donor is added; specifically:

[0098] In a closed environment, in the presence of organic solvent I, catalyst and hydrogen, the monomer is introduced into a stirred tank polymerization reactor to carry out a polymerization reaction, and the reacted material is obtained. The material is then expelled under pressure with nitrogen, filtered and dried to obtain 4-methyl-1-pentene homopolymer (named DZ2).

[0099] Except for the absence of an external electron donor, all other dosage parameters are the same as in Example 1.

[0100] Comparative Example 3

[0101] This comparative example uses a method similar to that of Example 1, except that Cat1 is replaced with an equal mass of Cat3; 4-methyl-1-pentene homopolymer was prepared by this method and named DZ3.

[0102] Test Example 1

[0103] The melt flow rate of the 4-methyl-1-pentene homopolymers prepared in the examples and comparative examples was tested according to GB / T3682.1-2018 standard. The test conditions were: temperature 260℃ and load 5kg. The results are shown in Table 1.

[0104] The density of the 4-methyl-1-pentene homopolymers prepared in the examples and comparative examples was determined. The density (method A) was tested according to GB / T1033.1-2008, and the results are shown in Table 1.

[0105] The melting temperature, crystallization temperature, enthalpy of melting, and enthalpy of crystallization of the 4-methyl-1-pentene homopolymers prepared in the examples and comparative examples were measured according to ASTM D3418-15, and the test conditions were as follows:

[0106] A 5 mg sample was heated to 250 °C at a rate of 10 °C / min under nitrogen protection and held at that temperature for 3 min to eliminate the influence of the sample's thermal history. Then, the sample was cooled to 20 °C at a rate of 10 °C / min to obtain the crystallization temperature (Tc) and enthalpy of crystallization (ΔHc). The sample was then heated to 250 °C at a rate of 10 °C / min to obtain the melting peak, melting point (Tm), and enthalpy of melting (ΔHm). The results are shown in Table 1.

[0107] The molecular weight and distribution coefficient of the 4-methyl-1-pentene homopolymers prepared in the examples and comparative examples were tested using gel permeation chromatography (GPC). The test conditions were as follows: the solvent was trichlorobenzene, the sample dissolution temperature was 160℃, the dissolution time was 120 minutes, the column size was 300.0 mm × 7.5 mm, and the permeation pore size was 10 μm. The results are shown in Table 1.

[0108] The flexural modulus and tensile modulus of the 4-methyl-1-pentene homopolymers prepared in the examples and comparative examples were tested. The tensile modulus was tested according to ASTM-D638, and the flexural modulus was tested according to ASTM-D790. The specific results are shown in Table 1.

[0109] Table 1

[0110]

[0111]

[0112] Table 1 shows the performance parameters of the 4-methyl-1-pentene homopolymers prepared by the examples and comparative examples. As can be seen from the above analysis, the 4-methyl-1-pentene homopolymers prepared by the method of the present invention have excellent rigidity (flexural modulus, tensile modulus) and high isotacticity.

[0113] Test Example 2

[0114] An exemplary selection was made of the polymer prepared in Example 1 and subjected to C... 13 Nuclear magnetic resonance (NMR) analysis, the analytical method is as follows:

[0115] The sample was dissolved in deuterated o-dichlorobenzene solvent at 150℃ to prepare a homogeneous solution with a concentration of 150 g / L, and then dissolved in an oil bath at 150℃ for 4 hours. The solution was then tested using an AV400 (Bruker, Switzerland) NMR instrument with a pulse width of 30°, a spectral width of 200 ppm, a pulse interval of 4 s, 30° angle proton decoupling, 6000 scans, and a relaxation time of 3 s. The results are as follows. Figure 1 As shown.

[0116] pass Figure 1 According to the method of calculating isotacticity, the isotacticity of the 4-methyl-1-pentene homopolymer prepared in Example 1 is 99%, which is higher than that of the 4-methyl-1-pentene homopolymer prepared in the comparative example.

[0117] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A 4-methyl-1-pentene homopolymer, characterized in that, The isotacticity of the 4-methyl-1-pentene homopolymer is ≥98%, the flexural modulus is >1100MPa, and the tensile modulus is >1500MPa.

2. The 4-methyl-1-pentene homopolymer according to claim 1, characterized in that, The density of the 4-methyl-1-pentene homopolymer is 0.832-0.833 g / cm³. 3 Its melting point is 220-240℃; And / or, at a temperature of 260°C, the melt mass flow rate at a load of 5 kg is 0.1-500 g / 10 min; And / or, the weight-average molecular weight of the 4-methyl-1-pentene homopolymer is 10,000 to 700,000, and the molecular weight distribution coefficient is 2 to 10.

3. A method for preparing the 4-methyl-1-pentene homopolymer according to claim 1 or 2, characterized in that, The method includes: polymerizing 4-methyl-1-pentene monomer in a closed environment in the presence of organic solvent I, a catalyst, an external electron donor, and hydrogen; wherein the catalyst is a non-cerotropy transition metal catalyst and an organoaluminum compound in a weight ratio of 1:0.1-2.

4. The method according to claim 3, characterized in that, The non-ceramic transition metal catalyst is a titanium metal catalyst, and the organoaluminum compound is a triethylaluminum compound.

5. The method according to claim 3 or 4, characterized in that, The preparation method of the non-ceramic transition metal catalyst includes: (1) Under a protective atmosphere, organic solvent II and MgCl2 are subjected to a first heating treatment to obtain mixed solution I; (2) The mixed solution I is subjected to a second heating treatment with an acid anhydride to obtain mixture I; (3) The mixture I, lipids, and non-ceramic transition metal chloride I are subjected to a third heat treatment to obtain mixture II; (4) The mixture II is subjected to a fourth heating treatment with non-ceramic transition metal chloride II to obtain the non-ceramic transition metal catalyst; The non-cyclic transition metal chloride I and the non-cyclic transition metal chloride II are of the same type.

6. The method according to claim 5, characterized in that, The weight ratio of MgCl2 to the acid anhydride is 1:0.1-10; And / or, in step (3), the weight ratio of the mixture I, the ester and the non-ceramic transition metal chloride I is 1:0.01-1:0.01-20; And / or, the weight ratio of the non-ceramic transition metal chloride I to the non-ceramic transition metal chloride II is 1:0.5-1.

7. The method according to claim 5, characterized in that, In step (1), the conditions for the first heat treatment include: a temperature of 120-150°C and a time of 1-3 hours; And / or, in step (2), the conditions for the second heat treatment include: a temperature of 120-150°C and a time of 1-3 hours; And / or, in step (3), the conditions for the third heat treatment include: a temperature of 100-120°C and a time of 1-4 hours; And / or, in step (4), the conditions for the fourth heat treatment include: a temperature of 100-120°C and a time of 1-4 hours.

8. The method according to claim 3 or 4, characterized in that, The conditions for the polymerization reaction include: a temperature of 20-85℃ and a time of 1-4h.

9. The method according to claim 3 or 4, characterized in that, The external electron donor is selected from at least one of cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, and diisobutyldimethoxysilane.

10. The use of the 4-methyl-1-pentene homopolymer according to claim 1 or 2 in plastic articles.

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