A supported nickel catalyst of phosphinic acid and its preparation method and application in olefin polymerization

Abstract

The application discloses a supported phosphine nickel catalyst, a preparation method thereof and application of the catalyst in olefin polymerization, and belongs to the technical field of catalysts. The preparation method comprises the following steps: mixing a ligand, a metal nickel source and an organic solvent under an inert gas atmosphere, adding a metal hydride after reaction at room temperature, obtaining a complex through reaction, adding the complex into an organic solvent in which a carrier has been dispersed, stirring, filtering, washing, and drying to obtain the supported phosphine nickel catalyst; and the structural formula of the ligand is beneficial effects: the application introduces OX groups at the para position of the metal center of the metal complex, improves the loading effect of the metal catalyst by introducing metal ions such as lithium, sodium and potassium to act with the carrier, and controllably exposes the metal active center of the catalyst, so that the metal active center can be coordinated with olefins to generate polyolefins, and the supported ability of the post-transition metal nickel catalyst is endowed, and the supported post-transition metal catalyst can be used to prepare high-energy and multifunctional polyolefin composites with high activity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalysts, in particular to a supported phosphine nickel catalyst, a preparation method thereof and application thereof in olefin polymerization. BACKGROUND

[0002] Polyolefins are one of the important polymer materials that affect human production and life. The annual output of synthetic plastics exceeds 380 million tons, accounting for more than half of the global plastic output. Despite the huge annual output of polyolefin materials, one of their biggest drawbacks is their non-polarity, which greatly limits their application in many fields. Modifying polyolefin materials by filling with various inorganic and organic fillers to prepare polyolefin composites is an important way to endow polyolefin materials with new functions, and is also an important source of functional materials needed to meet the needs of human production and life. With the wide application of polyolefins, the design and development of high-performance catalysts have also attracted great attention from all walks of life.

[0003] Currently, the research on polyolefins mainly focuses on two aspects. One is based on homogeneous system, and the polyolefins obtained by this method have a clear molecular structure, which is beneficial to their modification, making them useful for mechanism research. The other is based on heterogeneous system, which is usually applied to industrial polymerization of polyolefins. This method can better control the product morphology, thereby realizing continuous polymerization process and preventing reactor fouling. However, the differences between the above research directions pose a formidable challenge to the practical application in the industrialization of high-performance polyolefin catalysts.

[0004] The Chinese patent application document with publication number CN117510686A discloses a method for preparing morphology-controllable ultrahigh molecular weight polyethylene by in-situ polymerization and ultrahigh molecular weight polyethylene prepared therefrom. The preparation method comprises: preparing a phosphine-nickel catalyst solution formed by coordination of a phosphine ligand and Ni(COD)2; adding the phosphine-nickel catalyst solution to a polyethylene insoluble solvent, and introducing ethylene to perform a precipitation polymerization reaction to obtain morphology-controllable ultrahigh molecular weight polyethylene. The phosphine ligand has a structure as shown in formula (I): wherein R1 is selected from substituted or unsubstituted C1-C6 non-aromatic hydrocarbon group, hydroxyl group, substituted silicon group, substituted or unsubstituted phenyl group; R2, R3 and R4 are independently selected from hydrogen, fluorine, chlorine, bromine, iodine, substituted or unsubstituted C1-C6 non-aromatic hydrocarbon group, hydroxyl group, C6-C20 aryl group, oxygen-containing group, nitrogen-containing group, sulfur-containing group, boron-containing group; and the number average molecular weight of the ultrahigh molecular weight polyethylene is 1 million g / mol or more. However, the performance of the phosphine-nickel catalyst is poor, and therefore needs to be further improved. SUMMARY

[0005] The technical problem solved by the present application is how to solve the problem of poor activity of the existing polyolefin catalyst.

[0006] The present application solves the above technical problems by the following technical means:

[0007] The first aspect of the present application provides a preparation method of a supported phosphine nickel catalyst, comprising the following steps:

[0008] In an inert gas atmosphere, the ligand, the metal nickel source and the organic solvent are mixed, and after reaction at room temperature, the metal hydride is added, and the complex is obtained by reaction, and then the complex is added to the organic solvent in which the carrier has been dispersed, stirred, filtered, washed and dried to obtain the supported phosphine nickel catalyst.

[0009] The structural formula of the ligand is

[0010] Preferably, the metal nickel source is selected from any one or more of Ni(COD)2, Py2NiMe2 and (DME)NiBr2.

[0011] Preferably, the molar ratio of the ligand to the metal nickel source is 1:1.1.

[0012] Preferably, the organic solvent is selected from any one or more of tetrahydrofuran, petroleum ether, toluene, benzene, dichloromethane, tetrachloromethane, 1,4-dioxane and 1,2-dichloroethane.

[0013] Preferably, the metal hydride is selected from any one or more of lithium hydride, sodium hydride and potassium hydride.

[0014] Preferably, the carrier is selected from any one or more of silicon dioxide, magnesium oxide, titanium dioxide, zinc oxide, aluminum oxide, magnesium chloride, glass fiber, graphene, expanded graphite, ammonium polyphosphate and carbon black.

[0015] Preferably, the mass ratio of the complex to the carrier is 1:(20-50000).

[0016] The second aspect of the present application provides a supported phosphine nickel catalyst prepared by the above preparation method.

[0017] The third aspect of the present application provides an application of the above supported phosphine nickel catalyst in olefin polymerization.

[0018] The fourth aspect of the present application provides a phosphine ligand, the structural formula of which is as follows:

[0019]

[0020] The fifth aspect of the present application provides a complex, the structural formula of which is as follows:

[0021] wherein X is any one of Na, Li, K.

[0022] The present application has the beneficial effects of:

[0023] 1. The present disclosure provides a supported catalyst and its preparation method and application, starting from the source of transition metal catalyst, designing a metal catalyst complex structure with high loading effect, so that it can be efficiently and controllably loaded with various inorganic and organic fillers such as aluminum oxide, silicon dioxide, graphene, and ammonium polyphosphate to prepare a new type of supported catalyst. It has high thermal stability, catalytic activity and polymer molecular weight, and is used for preparing ultra-high molecular weight polyethylene.

[0024] 2. The supported catalyst creatively introduces OX groups at the para position of the metal center of the metal complex, improves the loading effect of the metal catalyst by introducing sodium metal ions and the carrier, and controllably exposes the metal active center of the catalyst, so that it can coordinate with olefins to generate polyolefins, giving the supported ability of the post-transition metal nickel catalyst, which can realize the preparation of high-energy and multifunctional polyolefin composites with high activity of the supported post-transition metal catalyst. At the same time, the method of in-situ preparation of polyolefin composites by post-transition metal catalyst is creatively proposed, which provides a new path for the preparation of functional composites. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The H NMR spectrum of the compound (II) in Example 1 of the present application is shown in Figure 1. 1 The H NMR spectrum of the compound (II) in Example 1 of the present application is shown in Figure 1.

[0026] Figure 2 The mass spectrum of the compound (II) in Example 1 of the present application is shown in Figure 2.

[0027] Figure 3 The H NMR spectrum of the supported phosphine nickel catalyst prepared in Example 2 of the present application is shown in Figure 3. 1 The H NMR spectrum of the compound (II) in Example 1 of the present application is shown in Figure 1.

[0028] Figure 4 The structure diagram of the supported phosphine nickel catalyst prepared in Example 2 of the present application is shown in Figure 4.

[0029] Figure 5 The actual picture of the supported phosphine nickel catalyst prepared in Example 2 of the present application is shown in Figure 5.

[0030] Figure 6 The morphology diagram of the supported phosphine nickel catalyst prepared in Example 2 of the present application is shown in Figure 6. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0032] The test materials and reagents used in the following examples, and the like, can be obtained from commercial channels unless otherwise specified.

[0033] The specific techniques or conditions not specified in the examples can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0034] The following examples illustrate the specific content of the present application, and the data given include the synthesis of ligands, the synthesis of catalysts, the ethylene polymerization or copolymerization method, wherein the synthesis of catalysts and the polymerization process are carried out in the absence of water and oxygen, all sensitive substances are stored in a glove box, all solvents are strictly dried and water-free, and ethylene gas is purified by a water and oxygen removal column. All supports are dried. Unless otherwise specified, all raw materials are commercially available.

[0035] Silica gel column: 200-300 mesh silica gel, NMR: Bruker 400MHz NMR instrument; elemental analysis was determined by the Physical and Chemical Center of China University of Science and Technology; molecular weight and molecular weight distribution were determined by GPC (polystyrene type column, HR2 and HR4, tank temperature was 45°C, Water 1515 and Water 2414 pumps were used; the mobile phase was tetrahydrofuran, the flow rate was 1.0 milliliter per minute, and polydispersed polystyrene was used as a standard); mass spectrometry was determined by Thermo LTQ Orbitrap XL (ESI+) or P-SIMS-Glyof Bruker Daltonics Inc (EI+); single crystal X-ray diffraction analysis used Oxford Diffraction Gemini SUltra CCD single crystal diffraction instrument, Cu Kα Radiation at room temperature.

[0036] Example 1: Preparation of 2-(ethylhydroxy)-6-((2',6'-dimethoxy-[1,1'-biphenyl]-2-yl)(phenyl)phosphino)benzene-1-ol (the structural formula is shown as (II) below)

[0037]

[0038] NaH (11 mmol) was added in portions to a dry THF solution of 2,6-dibromophenol (25 mmol), the mixture was stirred at 0°C for 30 minutes, then the mixture was stirred at 25°C for 30 minutes, then MOMCI (37.5 mmol) was added. The mixture was stirred at 25°C for 16 hours, neutralized with saturated solution of ammonium chloride, and extracted with DCM (3 x 30 mL). The combined organic phases were washed with brine and dried over anhydrous MgS04. At 0°C, n-BuLi (16 mmol) was added dropwise, after 2 h, chloro(2',6'-dimethoxy-[1,1'-biphenyl]-2-yl)(phenyl)phosphine (10 mmol) was added, slowly raised to room temperature, continued to react for 12 h, quenched with water, the organic phase was extracted with DCM, the obtained organic phase was concentrated, the organic phase was placed in THF (100 ml) at -78°C, n-BuLi (16 mmol) was added dropwise, after 3 hours, DMF (10 ml) was added for 12 hours, white oil was obtained, the mixture was placed in deoxygenated methanol, at 0°C, sodium borohydride was added. The mixture was concentrated in vacuum, the residue was dissolved in 20 mL of deoxygenated methanol and 2 ml of hydrochloric acid. The reaction was carried out for 3 h, neutralized with aqueous NaHC03solution, quenched with water, the organic phase was extracted with DCM, dried over anhydrous MgS04, filtered, concentrated, and fast column chromatography to obtain white solid, i.e. 2-(ethylhydroxy)-6-((2',6'-dimethoxy-[1,1'-biphenyl]-2-yl)(phenyl)phosphino)benzene-1-ol.

[0039] The mass spectrum of the compound (II) prepared in this example is shown in 1 The spectrum of H NMR is shown in Figure 1 1 H NMR (600 MHz, Chloroform-d) δ 7.44 (t, J = 6.7 Hz, 1H), 7.30 (m, 1H), 7.21 (m, 4H), 6.92 (m, 4H), 6.81 (t, J = 7.5 Hz, 1H), 6.68 (d, J = 6.6 Hz, 1H), 6.54 (t, J = 8.3 Hz, 1H), 4.67 (d, J = 15.2 Hz, 2H), 3.48 (s, 6H). Unknown NMR (243 MHz). ESI-MS (m / z): [M+H] + Calcd for Chemical Formula: C 27 H 25 O4P444.47; 444.156

[0040] The mass spectrum of the compound (II) prepared in this example is shown in Figure 2

[0041] Example 2:

[0042] ​​The compound (II) prepared in Example 1 is used as the ligand in this example.

[0043] A method for preparing a supported phosphine nickel catalyst, comprising the following steps:

[0044] The ligand (1.0 mmol), metal nickel source (Py2NiMe2, 1.1 mmol), organic solvent (toluene, 20 mL) are mixed and stirred under nitrogen gas atmosphere, and reacted at room temperature for 1 h to obtain a brown-yellow solution. Then, metal hydride (sodium hydride, 1.1 mmol) is added to continue the reaction. The solvent is removed under vacuum to obtain the complex. Then, 10 mg of the complex is added to the organic solvent (toluene, 10 mL) in which the support (SiO2, 1 g) has been dispersed, and stirred for 30 min. The solid is filtered, washed and dried to obtain (denoted as I1-Na-SiO2).

[0045] The structure of the catalyst prepared in this example is shown in 1 The spectrum of H NMR is shown in FIG. 3. 1 H NMR (400 MHz, Benzene-d6) δ 7.55 (dt, J = 16.5, 8.7 Hz, 2H), 7.35 (dd, J = 7.6, 4.4 Hz, 4H), 7.16 (d, J = 8.8 Hz, 3H), 7.00 (m, 2H), 6.88 (d, J = 7.8 Hz, 4H), 4.23 (s, 2H), 3.29 (s, 3H), 3.02 (s, 3H), -0.80 (d, J = 5.2 Hz, 3H). Anal. Calcd for C33H31NNiO4P: C, 66.58; H, 5.25; N, 2.35; Found: C, 66.02; H, 5.28; N, 2.30

[0046] The structure of the catalyst prepared in this example is shown in Figure 4 The actual image of the catalyst is shown in Figure 5 The morphology image of the catalyst is shown in Figure 6

[0047] Example 3:

[0048] The difference between this example and Example 2 is that the support is replaced by TiO2, and the rest is the same as Example 2. (The catalyst prepared is denoted as I2-Na-TiO2)

[0049] Example 4:

[0050] The difference between this example and Example 2 is that the support is replaced by ZnO, and the rest is the same as Example 2. (The catalyst prepared is denoted as I3-Na-ZnO)

[0051] Example 5: ​

[0052] The difference between this example and Example 2 is that the carrier is replaced by MgO, and the rest is the same as Example 2. (The prepared catalyst is recorded as I4-Na-MgO)

[0053] Example 6:

[0054] The difference between this example and Example 2 is that the carrier (SiO2, 200 mg), and the rest is the same as Example 2.

[0055] Example 7:

[0056] The difference between this example and Example 2 is that the carrier (SiO2, 500 g), and the rest is the same as Example 2.

[0057] Example 8:

[0058] The difference between this example and Example 2 is that sodium hydride is replaced by lithium hydride, and the rest is the same as Example 2.

[0059] Example 9:

[0060] The difference between this example and Example 2 is that sodium hydride is replaced by potassium hydride, and the rest is the same as Example 2.

[0061] Example 10:

[0062] The difference between this example and Example 2 is that Py2NiMe2 is replaced by Ni(COD)2, and the rest is the same as Example 2.

[0063] Example 11:

[0064] The difference between this example and Example 2 is that Py2NiMe2 is replaced by (DME)NiBr2, and the rest is the same as Example 2.

[0065] Comparative Example 1:

[0066] The difference between this example and Example 2 is that the complex is not loaded on the SiO2 carrier, and the rest is the same as Example 2.

[0067] Comparative Example 2:

[0068] The difference between this example and Example 2 is that sodium hydride is not added, and the rest is the same as Example 2. (The prepared catalyst is recorded as I-SiO2)

[0069] Application Example 1:

[0070] The supported phosphine nickel catalyst prepared in Example 2 is used to catalyze ethylene polymerization to prepare a polyolefin composite material, and the specific polymerization method is as follows:

[0071] In a glove box, and under nitrogen atmosphere, a 350 mL autoclave (with magnetic stirring device, oil bath heating device and thermometer) was charged with 90 mL of n-heptane, then the container was connected to the high pressure pipeline and the pipeline was vacuumed, and the container temperature was set to 80°C, and kept for 5 minutes; the supported catalyst prepared in Example 2 (100 mg) was dispersed in 10 mL of n-heptane, and injected into the autoclave by a syringe; then the ethylene valve was opened, and ethylene was introduced into the autoclave, and the ethylene pressure was adjusted to 8 atm, and the reaction was carried out for 30 minutes; then the reaction was stopped, the autoclave was opened, and ethanol was added to the autoclave to precipitate the solid, and the solid was filtered under reduced pressure, and dried in a vacuum drying oven to obtain a white solid. (The activity of the catalyst and the yield of the polyolefin are shown in Table 1 below)

[0072] Similarly, the catalysts prepared in Examples 3-5 and Comparative Examples 1-2 were used to catalyze the polymerization of ethylene to prepare polyolefin composites, and the specific polymerization method was the same as in Application Example 1. (The relevant test data are shown in Table 1 below)

[0073] Table 1

[0074]

[0075] wherein, a Polymerization conditions: n-heptane = 100 mL, ethylene = 8 atm, polymerization temperature 80°C; b c The melting point was determined by differential scanning calorimetry; c Weight average molecular weight = 10 4 g mol -1 The molecular weight was determined by GPC using polystyrene as a standard and chlorobenzene as a solvent at 150°C.

[0076] As can be seen from Table 1, the activity of the catalyst supported on the SiO2 carrier in Example 2 is 3-4 times higher than that of the catalyst without a carrier in Comparative Example 1. As can be seen from Example 2 and Comparative Example 2, after the introduction of sodium metal ions, the loading effect of the complex in the catalyst on the carrier is improved, and the activity of the catalyst is also improved, and the yield of the polyolefin obtained by catalysis is also higher.

[0077] The above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A process for the preparation of a supported nickel catalyst of a phosphinic acid, characterized in that, The method comprises the following steps: The ligand, the metal nickel source and the organic solvent are mixed under an inert gas atmosphere, and then the metal hydride is added after reaction at room temperature to obtain a complex, which is then added to the organic solvent in which the carrier is dispersed, stirred, filtered, washed and dried to obtain the supported phosphine nickel catalyst; The structural formula of the ligand is 2. The process for the preparation of supported nickel catalyst of phosphino phenol according to claim 1, characterized in that, The metal nickel source is selected from any one or more of Ni(COD)2, Py2NiMe2 and (DME)NiBr2; and the molar ratio of the ligand to the metal nickel source is 1:1.

1.

3. The process for the preparation of supported nickel catalyst of phosphino phenol according to claim 1, characterized in that, The organic solvent is selected from any one or more of tetrahydrofuran, petroleum ether, toluene, benzene, dichloromethane, tetrachloromethane, 1,4-dioxane and 1,2-dichloroethane.

4. The process for the preparation of supported nickel catalyst of phosphino phenol according to claim 1, characterized in that, The metal hydride is selected from any one or more of lithium hydride, sodium hydride and potassium hydride.

5. The process for the preparation of supported nickel catalyst of phosphino phenol according to claim 1, characterized in that, The carrier is selected from any one or more of silicon dioxide, magnesium oxide, titanium dioxide, zinc oxide, aluminum oxide, magnesium chloride, glass fiber, graphene, expanded graphite, ammonium polyphosphate and carbon black.

6. The process for the preparation of supported nickel catalyst of phosphino phenol according to claim 1, characterized in that, The mass ratio of the complex to the carrier is 1:(20-50000).

7. The supported phosphine nickel catalyst prepared by the preparation method in any one of claims 1-6.

8. The use of the supported phosphine nickel catalyst in claim 7 in olefin polymerization.

9. A phosphane phenol ligand, characterized in that The structural formula is as shown in the following:

10. A complex characterized by, The structural formula is as shown in the following: wherein X is any one of Na, Li, K.

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