Preparation method for polyolefin

Abstract

The present invention provides a preparation method for polyolefin. In the preparation method, a cycloolefin monomer is used as a gas phase, a catalyst is loaded on a substrate material, and the catalyst is a solid phase; the cycloolefin monomer undergoes a gas-solid polymerization reaction under the action of the catalyst to obtain polyolefin; and the loading capacity of the catalyst on the substrate material is 0.1-1000 ppm. According to the method of the present invention, the complex operation in the prior art is overcome, and a polyolefin product having an ultrahigh molecular weight and a narrow molecular weight distribution can be obtained.

Description

A method for preparing polyolefin

[0001] Cross-reference information

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on December 28, 2023, with application number 202311837594.7 and invention name “A Method for Preparing Polyolefins”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing polyolefin. Background Art

[0004] Ring-opening metathesis polymerization (ROMP) is a living polymerization reaction widely used in the synthesis of polyolefin materials. In most cases, polymerization is carried out in solution, where chain transfer side reactions limit the maximum molecular weight of the resulting product. When polymerization is carried out in the gas phase, polymer chain mobility is restricted, chain transfer side reactions are suppressed, and higher molecular weight products can be obtained. By polymerizing gaseous cycloolefin monomers supported on a solid substrate, the resulting polycyclopentene can achieve a number-average molecular weight exceeding 1 million, more than three times the molecular weight limit of existing solution polymerization methods, while maintaining a polydispersity coefficient of less than 1.5. Hydrogenation of the resulting material yields ultrahigh molecular weight, unbranched polyethylene. This polymerization method is applicable to many monomers commonly used in ring-opening metathesis polymerization, such as cyclopentene, cyclohexadiene, cycloheptene, norbornene, cyclooctene, 1,5-cyclooctadiene, cyclooctatetraene, and 1,5,9-cyclododecatriene. At the same time, because the reaction process avoids the use of solvents, production costs and environmental pollution are reduced.

[0005] In the prior art, because the amount of the obtained product is insufficient for molecular weight detection, there is a lack of characterization of the product molecular weight or polydispersity coefficient. Summary of the Invention

[0006] To address the above-mentioned issues, the present invention provides a method for preparing polyolefins. This method overcomes the cumbersome operations of the prior art by loading a catalyst onto a substrate in a reaction vessel and conducting a gas-solid polymerization reaction to obtain a polyolefin product with an ultrahigh molecular weight and a narrow molecular weight distribution.

[0007] The present invention provides a method for preparing polyolefin, wherein cycloolefin monomer is used as gas phase, a catalyst is supported on a substrate material, and the catalyst is in solid phase;

[0008] causing the cycloolefin monomer to undergo a gas-solid polymerization reaction under the action of the catalyst to obtain the polyolefin;

[0009] The loading amount of the catalyst on the base material is 0.1 to 1000 ppm, preferably 0.5 to 1000 ppm, more preferably 0.5 to 50 ppm.

[0010] After adding purified cycloolefin monomers that are not in direct contact with the substrate, the volatilized monomers in the gas phase come into contact with the solid-phase catalyst, leading to a gas-solid polymerization reaction, which produces a polyolefin product with an ultrahigh molecular weight and a narrow molecular weight distribution. By controlling the catalyst loading, the molecular weight of the product can be controlled. Using a highly efficient ROMP catalyst allows the reaction to exhibit the characteristics of active polymerization, with the polymerization reaction occurring at the gas-solid interface. Purification of the monomers reduces the content of non-cycloolefin impurities, minimizing chain transfer side reactions during the polymerization process, ultimately yielding a polymer product with a narrow molecular weight distribution.

[0011] After the reaction is completed, the product is peeled off from the base material to obtain the product.

[0012] In actual production operations, cycloolefin raw materials may contain linear olefin impurities. These impurities act as chain transfer agents, reducing the product molecular weight and broadening the molecular weight distribution during polymerization. Therefore, it is very important to purify the monomer to remove the linear olefins. Methods for monomer purification include distillation, hydroboration, or a combination of the two. In the hydroboration method, borane molecules are added to the monomer. Borane has high reactivity with linear olefins. The resulting hydroboration product has a high boiling point, is difficult to volatilize, and is non-reactive, thus not affecting the polymerization process. The borane molecule is shown in Formula 6, where R1 and R2 are the same or different C1-C20 hydrocarbon groups. R1 and R2 can be linked to form a monocyclic or polycyclic group. The preferred borane is 9-borabicyclo[3.3.1]nonane (9-BBN). The amount of borane added depends on the content of linear olefin impurities in the monomer, preferably 5 to 20 times the molar amount of the impurities. The present invention preferably uses a method of first purifying the monomer by distillation, followed by hydroboration to further reduce the impurity content.

[0013] In a preferred embodiment of the present invention, the method for loading the catalyst comprises:

[0014] The catalyst and an organic solvent are prepared into a catalyst solution, the catalyst solution is distributed on the substrate material, and then the organic solvent is removed.

[0015] In a preferred embodiment of the present invention, the organic solvent is one or a combination of two or more of linear aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, and aromatic hydrocarbons. More advantageously, the organic solvent is an aromatic hydrocarbon.

[0016] In a preferred embodiment of the present invention, the concentration of the catalyst solution is 1 to 2000 μmol / L. More advantageously, the concentration of the catalyst solution is 5 to 600 μmol / L.

[0017] In a preferred embodiment of the present invention, the catalyst comprises one or a combination of two or more of a ruthenium ROMP catalyst, a tungsten ROMP catalyst, a molybdenum ROMP catalyst, and a rhenium ROMP catalyst. More advantageously, the catalyst is Grubbs 1st and / or Grubbs 2nd.

[0018] In a preferred embodiment of the present invention, the substrate material comprises one of glass, silicon wafer, paper, aluminum foil, stainless steel, and plastic. Preferably, the substrate material is placed at the bottom of the reactor.

[0019] More preferably, the substrate material is glass or paper.

[0020] In a preferred embodiment of the present invention, the reaction temperature of the gas-solid polymerization reaction is -80°C to 200°C, and the reaction time is 30 minutes to 12 hours. More advantageously, the reaction temperature is 0°C to 30°C, and the reaction time is 1 hour to 6 hours.

[0021] As the reaction temperature decreases, the molecular weight of the polymer increases.

[0022] In actual operation, it is preferred to provide the reaction temperature using a liquid medium outside the reactor.

[0023] By regulating the reaction temperature, the molecular weight of the product obtained by the preparation method of the present invention can be controlled.

[0024] In a preferred embodiment of the present invention, the cycloolefin monomer comprises one or a combination of two or more of the cycloolefins represented by Formula 1, Formula 2, Formula 3, Formula 4, and Formula 5;

[0025] Wherein, in Formula 1, n=1, 3, 4 or 8.

[0026] In a preferred embodiment of the present invention, the method for removing the organic solvent comprises: drying the organic solvent with an inert gas;

[0027] Preferably, the temperature of the inert gas is 0-50°C. More preferably, the temperature of the inert gas is 20-30°C.

[0028] Preferably, the inert gas is selected from nitrogen and / or argon.

[0029] In some embodiments of the present invention, the method of loading the catalyst comprises a spin coating method.

[0030] The present invention also provides two reactors suitable for the preparation method of the present invention.

[0031] The structural schematic diagram of reactor A is shown in FIG1 , and the structural schematic diagram of reactor B is shown in FIG2 .

[0032] In reactor A, the outer bottle 5 has a gasket 1 on top, which is fixed and sealed by a lid 2 with a hole in the middle. The top of the inner bottle 4 is bolted with a wire 3, which passes through the gasket 1 and is fixed, hanging in the outer bottle 5.

[0033] In reactor B, outer bottle 5 is topped with a gasket 1, which is secured and sealed by a lid 2 with a hole in the center. Base 7 is perforated and passed through a wire 3, which is then passed through gasket 1 to secure it, leaving base 7 suspended in the outer bottle 5. Paper 6 adheres closely to the inner wall of outer bottle 5 and touches the bottom, soaking it in the monomer liquid to accelerate its evaporation.

[0034] The main body of reactors A and B is made of glass.

[0035] The above reactor A and reactor B are only used as examples, and are not intended to further limit the preparation method of the present invention.

[0036] The preparation method of the present invention can produce ultrahigh molecular weight polyolefins. To achieve a lower product molecular weight, a certain amount of linear olefin can be added to the reaction monomers. The linear olefin has the structural formula shown in Formula 7, where R3 and R4 are the same or different C1-C10 hydrocarbon groups or hydrogen. Those skilled in the art can determine the specific linear olefin to be used and the amount to be added based on common knowledge in the art and limited experimentation.

[0037] Compared with the prior art, the present invention has the following advantages: the preparation method of the present invention is relatively simple to operate, and can obtain a polyolefin product with ultrahigh molecular weight and narrow molecular weight distribution in a high yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG1 shows a schematic structural diagram of a reactor A.

[0039] FIG2 shows a schematic structural diagram of reactor B.

[0040] FIG3 shows the solid-state carbon NMR spectrum of the product obtained in Synthesis Example 1.

[0041] The markings in the figure include: 1-pad, 2-cover, 3-wire, 4-inner bottle, 5-outer bottle, 6-paper, 7-base. DETAILED DESCRIPTION

[0042] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0043] In the following examples, number-average molecular weight, weight-average molecular weight, and molecular weight distribution coefficient were measured using a size-exclusion gel chromatography instrument. The instrument consisted of an Agilent 1260 liquid pump, two Agilent PLgel MIXED-B 300 × 7.5 mm columns connected in series, a Wyatt 18-degree DAWN HELEOS light-dispersive detector, and a Wyatt Optilab rEX differential refractometer. Tetrahydrofuran was used as the solvent and mobile phase at a concentration of 1 g / L and a flow rate of 1 mL / min.

[0044] In the following examples and comparative examples, reactor A has the structure shown in FIG1 , and reactor B has the structure shown in FIG2 .

[0045] In reactor A, the outer bottle 5 has a gasket 1 on top, which is fixed and sealed by a lid 2 with a hole in the middle. The top of the inner bottle 4 is bolted with a wire 3, which is fixed through the gasket 1 and suspended in the outer bottle 5.

[0046] In reactor B, outer bottle 5 has a gasket 1 on top, secured and sealed by a lid 2 with a hole in the center. Base 7 has a hole and is passed through a wire 3, which is passed through gasket 1 and secured, leaving base 7 suspended in outer bottle 5. Paper 6 adheres closely to the inner wall of outer bottle 5 and touches the bottom.

[0047] Example 1

[0048] This example uses Reactor A. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was then placed in a 20°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 20°C oil bath for 30 minutes. 2 ml of the solution was syringed out and added to the bottom of inner bottle 4. The reactor was then placed in a 20°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0049] Example 2

[0050] This example uses Reactor A. Weigh 2.3 mg of Grubbs 1st catalyst and dissolve it in 50 ml of toluene to obtain a catalyst solution. Use a syringe to add 2 ml of the catalyst solution to the bottom of outer bottle 5, and place the reactor in a 20°C oil bath. Purge the reactor with argon for 30 minutes until the solvent is completely evaporated. Mix 50 ml of cyclopentene purified by distillation with 50 mg of 9-BBN in a sealed glass bottle and stir for 12 hours. The glass bottle is then placed in a 20°C oil bath for 30 minutes. Use a syringe to add 2 ml of the solution to the bottom of inner bottle 4. The reactor is placed in a 20°C oil bath and reacted for 6 hours to obtain a polymer. Polymer properties and yields are shown in Table 1.

[0051] Example 3

[0052] This example uses Reactor A. Weigh 0.92 mg of Grubbs 1st catalyst and dissolve it in 200 ml of toluene to obtain a catalyst solution. Use a syringe to add 2 ml of the catalyst solution to the bottom of outer bottle 5, and place the reactor in a 20°C oil bath. Purge the reactor with argon for 30 minutes until the solvent is completely evaporated. Mix 50 ml of cyclopentene purified by distillation with 50 mg of 9-BBN and stir in a sealed glass bottle for 12 hours. The glass bottle is then placed in a 20°C oil bath for 30 minutes. Use a syringe to add 2 ml of the solution to the bottom of inner bottle 4. The reactor is placed in a 20°C oil bath and reacted for 6 hours to obtain a polymer. Polymer properties and yields are shown in Table 1.

[0053] Example 4

[0054] This example uses Reactor A. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed in and added to the bottom of outer bottle 5. The reactor was then placed in a 30°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent evaporated completely. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 30°C oil bath for 30 minutes. 2 ml of the solution was syringed in and added to the bottom of inner bottle 4. The reactor was then placed in a 30°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0055] Example 5

[0056] This example uses Reactor A. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 50 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was then placed in a 30°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent evaporated completely. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 30°C oil bath for 30 minutes. 2 ml of the solution was syringed out and added to the bottom of inner bottle 4. The reactor was then placed in a 30°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0057] Example 6

[0058] This example uses Reactor A. Weigh 0.92 mg of Grubbs 1st catalyst and dissolve it in 200 ml of toluene to obtain a catalyst solution. Use a syringe to add 2 ml of the catalyst solution to the bottom of outer bottle 5, and place the reactor in a 30°C oil bath. Purge the reactor with argon for 30 minutes until the solvent is completely evaporated. Mix 50 ml of cyclopentene purified by distillation with 50 mg of 9-BBN and stir in a sealed glass bottle for 12 hours. The glass bottle is then placed in a 30°C oil bath for 30 minutes, and 2 ml of the solution is added to the bottom of inner bottle 4 using a syringe. The reactor is placed in a 30°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0059] Example 7

[0060] This example uses Reactor A. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5, and the reactor was placed in a 0°C ice-water bath. The reactor was purged with argon for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 0°C ice-water bath for 30 minutes, and 2 ml of the solution was syringed out and added to the bottom of inner bottle 4. The reactor was placed in a 0°C ice-water bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0061] Example 8

[0062] This example uses Reactor A. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 50 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5, and the reactor was placed in a 0°C ice-water bath. The reactor was purged with argon for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 0°C ice-water bath for 30 minutes, and 2 ml of the solution was syringed out and added to the bottom of inner bottle 4. The reactor was placed in a 0°C ice-water bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0063] Example 9

[0064] This example uses Reactor A. Weigh 0.92 mg of Grubbs 1st catalyst and dissolve it in 200 ml of toluene to obtain a catalyst solution. Use a syringe to add 2 ml of the catalyst solution to the bottom of outer bottle 5, and place the reactor in a 0°C ice-water bath. Purge the reactor with argon for 30 minutes until the solvent is completely evaporated. Mix 50 ml of cyclopentene purified by distillation with 50 mg of 9-BBN and stir in a sealed glass bottle for 12 hours. The glass bottle is then placed in a 0°C ice-water bath for 30 minutes, and 2 ml of the solution is added to the bottom of inner bottle 4 using a syringe. The reactor is placed in a 0°C ice-water bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0065] Example 10

[0066] This example uses Reactor A. 2.4 mg of Grubbs 2nd catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was then placed in a 20°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 20°C oil bath for 30 minutes. 2 ml of the solution was syringed out and added to the bottom of inner bottle 4. The reactor was then placed in a 20°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0067] Example 11

[0068] This example uses Reactor A. 2.4 mg of Grubbs 2nd catalyst was weighed and dissolved in 50 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was then placed in a 20°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 20°C oil bath for 30 minutes. 2 ml of the solution was syringed out and added to the bottom of inner bottle 4. The reactor was then placed in a 20°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0069] Example 12

[0070] This example uses Reactor A. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was then placed in a 30°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent evaporated completely. 50 ml of cycloheptene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 30°C oil bath for 30 minutes. 2.6 ml of the solution was syringed out and added to the bottom of inner bottle 4. The reactor was then placed in a 30°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0071] Example 13

[0072] Reactor B was used in this example. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was taken with a syringe and added to a glass dish. Paper 6 was immersed in the catalyst solution to soak the entire solution in the paper 6. Paper 6 was made of filter paper. After purging the filter paper with argon for 30 minutes until the solvent was completely evaporated, the paper 6 was fixed to the silica gel pad 1 with wire 3 and suspended in the outer bottle 5. 50 ml of cycloheptene purified by distillation was mixed with 50 mg of 9-BBN. After stirring in a sealed glass bottle for 12 hours, the glass bottle was placed in a 30°C oil bath for 30 minutes. 2.6 ml of the solution was taken with a syringe and added to the bottom of the outer bottle 5. The reactor was placed in a 30°C oil bath for reaction for 6 hours to obtain a polymer. The polymer properties and yield are shown in Table 1.

[0073] Example 14

[0074] This example uses Reactor A. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed into the bottom of outer bottle 5, and the reactor was placed in a 20°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent evaporated completely. 50 ml of undistilled cyclopentene was placed in a 20°C oil bath for 30 minutes. 2 ml of the solution was syringed into the bottom of inner bottle 5. The reactor was allowed to react in the 20°C oil bath for 6 hours to produce a polymer. Polymer properties and yields are shown in Table 1.

[0075] Comparative Example 1

[0076] Reactor A was used in this comparative example. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 5 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was placed in a 20°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN and stirred in a sealed glass bottle for 12 hours. The glass bottle was then placed in a 20°C oil bath for 30 minutes. 2 ml of the solution was syringed out and added to the bottom of outer bottle 5. The reactor was placed in a 20°C oil bath and reacted for 6 hours to obtain a polymer. Polymer properties and yields are shown in Table 1.

[0077] Comparative Example 2

[0078] Reactor A was used in this comparative example. 2.3 mg of Grubbs 1st catalyst was weighed and dissolved in 50 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was placed in a 20°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN. After stirring for 12 hours in a sealed glass bottle, the glass bottle was placed in a 20°C oil bath for 30 minutes. 2 ml of the solution was syringed out and added to the bottom of outer bottle 5. The reactor was placed in a 20°C oil bath and reacted for 6 hours to obtain a polymer. The polymer properties and yield are shown in Table 1.

[0079] Comparative Example 3

[0080] Reactor A was used in this comparative example. 0.92 mg of Grubbs 1st catalyst was weighed and dissolved in 200 ml of toluene to obtain a catalyst solution. 2 ml of the catalyst solution was syringed out and added to the bottom of outer bottle 5. The reactor was placed in a 20°C oil bath. Argon was purged into the reactor for 30 minutes until the solvent was completely evaporated. 50 ml of cyclopentene purified by distillation was mixed with 50 mg of 9-BBN. After stirring for 12 hours in a sealed glass bottle, the glass bottle was placed in a 20°C oil bath for 30 minutes. 2 ml of the solution was syringed out and added to the bottom of outer bottle 5. The reactor was placed in a 20°C oil bath for 6 hours to obtain a polymer. Polymer properties and yields are shown in Table 1.

[0081] The results of the Examples and Comparative Examples demonstrate that gas-solid polymerization yields polymers with higher molecular weights than solution polymerization. The molecular weight of the polymers further increases as the reaction temperature decreases. Due to limitations of the analytical instrumentation, only polymer samples that are soluble at room temperature can be measured. In some cases, the polymers are partially insoluble at room temperature. Therefore, it is speculated that the actual polymer molecular weight is higher than the measured result.

[0082] Synthesis example 1

[0083] 1 g of the polymer obtained in Example 7 was added to a 100 ml round-bottom flask, and 5 mg of 2,6-di-tert-butyl-4-methylphenol and 70 ml of xylene were added; after heating and refluxing at 140° C. until the polymer was dissolved, 12.5 ml of tributylamine and 9 g of p-toluenesulfonylhydrazide were added, and stirring was continued for 12 hours; the hot solution was poured into 500 ml of cold methanol for precipitation, and the resulting solid was vacuum dried to obtain 1.03 g of a white solid; as shown in FIG3 , solid-state nuclear magnetic resonance carbon spectroscopy CP / MAS was used. 13 C NMR showed that the product had a peak only at 35 ppm, and no peak was found in the range of 100 to 150 ppm, which indicated that the double bonds in the raw material were completely hydrogenated and the product was unbranched polyethylene.

[0084] Table 1

[0085] It can be seen from the contents of Table 1 that the technical solution of the present invention can obtain a polyolefin product with ultra-high molecular weight and narrow molecular weight distribution.

Claims

1. A method for preparing a polyolefin, wherein, Using a cycloolefin monomer as the gas phase and loading the catalyst on a substrate material, the catalyst being in the solid phase; Subjecting the cycloolefin monomer to a gas-solid polymerization reaction under the action of the catalyst to obtain the polyolefin; The loading amount of the catalyst on the substrate material is 0.1 to 1000 ppm.

2. The preparation method according to claim 1, wherein The loading amount of the catalyst on the substrate material is 0.5 to 1000 ppm.

3. The preparation method according to claim 1, wherein, The method for loading the catalyst includes: Preparing a catalyst solution by mixing the catalyst with an organic solvent, distributing the catalyst solution on the substrate material, and then removing the organic solvent.

4. The preparation method according to claim 3, wherein, The organic solvent is one or a combination of two or more of linear aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, and aromatic hydrocarbons.

5. The preparation method according to claim 3, wherein, The concentration of the catalyst solution is 1 to 2000 μmol / L.

6. The preparation method according to claim 1, wherein, The catalyst includes one or a combination of two or more of ruthenium ROMP catalysts, tungsten ROMP catalysts, molybdenum ROMP catalysts, and rhenium ROMP catalysts.

7. The preparation method according to claim 1, wherein, The substrate material includes one of glass, silicon wafers, paper, aluminum foil, stainless steel, and plastics.

8. The preparation method according to claim 1 or 7, wherein, The substrate material is placed at the bottom of the reactor.

9. According to the preparation method described in claim 1, wherein, The reaction temperature of the gas-solid polymerization reaction is -80 to 200 °C, and the reaction time is 30 min to 12 h.

10. The preparation method according to claim 1, wherein, The cycloolefin monomer includes one or a combination of two or more of the cycloolefins represented by Formula 1, Formula 2, Formula 3, Formula 4, and Formula 5; Wherein, n = 1, 3, 4 or 8.

11. The preparation method according to claim 3, wherein, The method for removing the organic solvent includes: drying the organic solvent with an inert gas.

12. The preparation method according to claim 11, wherein, The temperature of the inert gas is 0 to 50 °C.

13. The preparation method according to claim 1, wherein, Before the gas-solid polymerization reaction, the preparation method further includes a purification treatment of the cycloolefin monomer.

14. The preparation method according to claim 13, wherein, The purification treatment of the cycloolefin monomer includes rectification and / or hydroboration.

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