Supported phosphine phenol nickel catalyst, preparation method thereof and application of supported phosphine phenol nickel catalyst in olefin polymerization

Abstract

The invention discloses a supported phosphine phenol nickel catalyst as well as a preparation method and application thereof in olefin polymerization, and belongs to the technical field of catalysts. Comprising the following steps: in an inert gas atmosphere, mixing a ligand, a metal nickel source and an organic solvent, reacting at room temperature, adding a metal hydride, reacting to obtain a complex, adding the complex into the organic solvent in which a carrier is dispersed, stirring, filtering, washing, and drying to obtain the catalyst. The preparation method has the beneficial effects that an OX group is introduced to the para-position of a metal center of a metal complex, and metal ions such as lithium, sodium and potassium are introduced to act with a carrier, so that the loading effect of the metal catalyst is improved, and the metal active center of the catalyst is controllably exposed, so that the metal active center can be coordinated and inserted with olefin to generate polyolefin; the loading capacity of the late transition metal nickel catalyst is endowed, and the high activity of the loaded late transition metal catalyst can be realized to prepare the high-new-energy multifunctional polyolefin composite material.

Description

Technical Field

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

[0002] Polyolefin is one of the important polymer materials that affects human production and life. The annual output of synthetic plastics exceeds 380 million tons, accounting for more than half of the global plastic production. Despite the huge annual output of polyolefin materials, one of their biggest disadvantages is their non-polarity, which greatly limits their application in many fields. Filling and modifying polyolefin materials with various inorganic and organic fillers to prepare polyolefin composites is an important way to give polyolefin materials new functions and is also an important source of functional materials currently needed to meet human production and life needs. With the widespread application of polyolefins, the design and development of high-performance catalysts has also received great attention from all walks of life.

[0003] At present, the research on polyolefins is mainly focused on two aspects. The first is based on the homogeneous system. The polyolefins obtained by this method have a clear molecular structure, which is conducive to their modification, making them useful for mechanism research. The second is based on the heterogeneous system. This method is usually used in the industrial polymerization of polyolefins. This method can better control the product morphology, thereby realizing a continuous polymerization process and preventing reactor fouling. However, the differences in the above research directions have posed a daunting challenge to the practical application of high-performance polyolefin catalyst industrialization research.

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

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

[0006] The present invention solves the above technical problems through the following technical means:

[0007] The first aspect of the present invention provides a method for preparing a supported nickel phosphine phenolate catalyst, comprising the following steps:

[0008] In an inert gas atmosphere, a ligand, a metal nickel source and an organic solvent are mixed, reacted at room temperature, and then a metal hydride is added to react to obtain a complex, and then the complex is added to an organic solvent in which a carrier is dispersed, stirred, filtered, washed and dried to obtain the complex;

[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 metallic 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 invention provides a supported nickel phosphine phenolate catalyst prepared by the above preparation method.

[0017] The third aspect of the present invention provides the use of the above-mentioned supported nickel phosphine phenolate catalyst in olefin polymerization.

[0018] The fourth aspect of the present invention provides a phosphophenol ligand, the structural formula of which is shown below:

[0019]

[0020] The fifth aspect of the present invention provides a complex, the structural formula of which is shown below:

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

[0022] The beneficial effects of the present invention are:

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

[0024] 2. The supported catalyst creatively introduces an OX group at the para position of the metal center of the metal complex, and improves the loading effect of the metal catalyst by introducing sodium metal ions to interact with the carrier, and can controllably expose the metal active center of the catalyst so that it can coordinate with olefins to form polyolefins, giving the late transition metal nickel catalyst the ability to load, and can achieve high-activity preparation of high-energy, multifunctional polyolefin composites with supported late transition metal catalysts. At the same time, a method for in-situ preparation of polyolefin composites with late transition metal catalysts was creatively proposed, providing a new path for the preparation of functional composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the compound (II) in Example 1 of the present invention 1 H NMR spectrum;

[0026] Figure 2 is the mass spectrum of compound (II) in Example 1 of the present invention;

[0027] Figure 3 The supported phosphine phenol nickel catalyst prepared in Example 2 of the present invention 1 H NMR spectrum;

[0028] Figure 4 Schematic diagram of the structure of the supported nickel phosphine phenolate catalyst prepared in Example 2 of the present invention;

[0029] Figure 5 This is a physical picture of the supported nickel phosphine phenolate catalyst prepared in Example 2 of the present invention;

[0030] Figure 6 This is a morphology diagram of the supported phosphine phenol nickel catalyst prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0033] If no specific techniques or conditions are specified in the examples, they 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 invention, and the data provided include the synthesis of the ligand, the synthesis of the catalyst, the ethylene polymerization or copolymerization method, wherein the synthesis of the catalyst and the polymerization process are all carried out under anhydrous and oxygen-free conditions, all sensitive substances are stored in a glove box, all solvents are strictly dried and dehydrated, and ethylene gas is purified by a dehydration and deoxygenation column. All carriers are dried. Unless otherwise specified, all raw materials are purchased from the market.

[0035] The silica gel column used 200-300 mesh silica gel, and the nuclear magnetic resonance used a Bruker 400MHz nuclear magnetic resonance instrument; the elemental analysis was determined by the Physical and Chemical Center of the University of Science and Technology of China; the molecular weight and molecular weight distribution were determined by GPC (polystyrene columns, HR2 and HR4, the box temperature was 45°C, using Water 1515 and Water 2414 pumps; the mobile phase was tetrahydrofuran, the flow rate was 1.0 ml per minute, and polydisperse polystyrene was used as the standard); the mass spectrometry was determined by Thermo LTQ Orbitrap XL (ESI+) or P-SIMS-Glyof Bruker Daltonics Inc (EI+); the single crystal X-ray diffraction analysis was performed using an Oxford Diffraction Gemini SUltra CCD single crystal diffraction instrument, Cu Kα Room temperature radiation.

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

[0037]

[0038] NaH (11 mmol) was added proportionally to a solution of 2,6-dibromophenol (25 mmol) in dry tetrahydrofuran, and the mixture was stirred at 0°C for 30 minutes, then stirred at 25°C for 30 minutes, and MOMCl (37.5 mmol) was added. The mixture was stirred at 25°C for 16 hours, neutralized with a saturated solution of ammonium chloride, and extracted with DCM (3×30 mL). The combined organic phases were washed with brine and dried over anhydrous MgSO4. Place at 0°C, add n-BuLi (16 mmol) dropwise, react for 2 hours, add chloro(2',6'-dimethoxy-[1,1'-biphenyl]-2-yl)(phenyl)phosphine (10 mmol), slowly warm to room temperature, continue to react for 12 hours, quench with water, extract the organic phase with DCM, concentrate the obtained organic phase, place the organic phase in THF (100 ml) at -78°C, add n-BuLi (16 mmol) dropwise, add DMF (10 ml) after 3 hours for 12 hours to obtain a white oil, place the mixture in deoxygenated methanol, and add sodium borohydride at 0°C. Concentrate the mixture in vacuo, and dissolve the residue in 20 mL of degassed methanol and 2 ml of hydrochloric acid. The mixture was reacted for 3 h, and an aqueous NaHCO3 solution was added for neutralization. The mixture was quenched with water. The organic phase was extracted with DCM, dried over anhydrous MgSO4, filtered, concentrated, and flash column chromatography was performed to obtain a white solid, namely 2-(ethylhydroxy)-6-((2',6'-dimethoxy-[1,1'-biphenyl]-2-yl)(phenyl)phosphino)benzene-1-ol.

[0039] The compound (II) prepared in this example 1 The H NMR spectrum is as follows Figure 1 shown. 1 H NMR(600MHz,Chloroform-d)δ7.44(t,J=6.7Hz,1H),7.30(m,1H),7.21(m,4H),6.92(m,4H),6.81(t,J= 7.5Hz,1H),6.68(d,J=6.6Hz,1H),6.54(t,J=8.3Hz,1H),4.67(d,J=15.2Hz,2H),3.48(s,6H).Unknown NMR(243MHz).ESI-MS(m / z):[M+H] + Calcd for Chemical Formula:C 27 H 25 O4P444.47;444.156

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

[0041] Embodiment 2:

[0042] In this example, the compound (II) prepared in Example 1 was used as a ligand.

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

[0044] Under a nitrogen atmosphere, the ligand (1.0 mmol), metal nickel source (Py2NiMe2, 1.1 mmol), and organic solvent (toluene, 20 mL) were mixed and stirred, reacted at room temperature for 1 h, filtered to obtain a brown-yellow solution, and metal hydride (sodium hydride, 1.1 mmol) was added to react, and the solvent was removed in vacuo to obtain a complex. Then 10 mg of the complex was added to an organic solvent (toluene, 10 mL) in which a carrier (SiO2, 1 g) was dispersed, stirred for 30 min, filtered, the solid was washed, and dried to obtain (denoted as I1-Na-SiO2).

[0045] The catalyst prepared in this example 1 The H NMR spectrum is shown in Figure 3. 1 H NMR(400MHz,Benzene-d6)δ7.55(dt,J=16.5,8.7Hz,2H),7.35(dd,J=7.6,4.4Hz,4H),7.16(d,J=8.8Hz,3H),7 .00(m,2H),6.88(d,J=7.8Hz,4H),4.23(s,2H),3.29(s,3H),3.02(s,3H),-0.80(d,J=5.2Hz,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 structural schematic diagram of the catalyst prepared in this embodiment is as follows Figure 4 The actual picture of the catalyst is shown in Figure 5 The morphology of the catalyst is shown in Figure 6 shown.

[0047] Embodiment 3:

[0048] The difference between this embodiment and embodiment 2 is that the carrier is replaced with TiO2, and the rest is the same as embodiment 2. (The prepared catalyst is recorded as I2-Na-TiO2)

[0049] Embodiment 4:

[0050] The difference between this embodiment and embodiment 2 is that the carrier is replaced by ZnO, and the rest is the same as embodiment 2. (The prepared catalyst is recorded as I3-Na-ZnO)

[0051] Embodiment 5:

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

[0053] Embodiment 6:

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

[0055] Embodiment 7:

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

[0057] Embodiment 8:

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

[0059] Embodiment 9:

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

[0061] Embodiment 10:

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

[0063] Embodiment 11:

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

[0065] Comparative Example 1:

[0066] The difference between this comparative 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 comparative example and Example 2 is that no sodium hydride is 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 nickel phosphine phenolate catalyst prepared in Example 2 was used to catalyze ethylene polymerization to prepare the polyolefin composite material. The specific polymerization method is as follows:

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

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

[0073] Table 1

[0074]

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

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

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

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

1.

3. The method for preparing a supported nickel phosphine phenolate catalyst according to claim 1, wherein 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 method for preparing a supported nickel phosphine phenolate catalyst according to claim 1, wherein The metal hydride is selected from any one or more of lithium hydride, sodium hydride and potassium hydride.

5. The method for preparing a supported nickel phosphine phenolate catalyst according to claim 1, wherein: 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 method for preparing a supported nickel phosphine phenolate catalyst according to claim 1, wherein: The mass ratio of the complex to the carrier is 1:(20-50000).

7. A supported nickel phosphine phenolate catalyst prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the supported nickel phosphine phenolate catalyst according to claim 7 in olefin polymerization.

9. A phosphophenol ligand, characterized in that Its structural formula is as follows:

10. A complex, characterized in that Its structural formula is as follows: Wherein X is any one of Na, Li and K.

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