A pyridine tridentate ligand iron complex, a preparation method and application thereof, and a preparation method of polyisobutylene

Abstract

The application provides a pyridine tridentate ligand iron complex and a preparation method and application thereof, and a preparation method of polyisobutylene, and belongs to the technical field of catalyst preparation. The metal complex (pyridine tridentate ligand iron complex) provided by the application has a complex spatial structure, so that isobutylene monomers cannot freely coordinate with the metal center to further react. Only in a suitable direction, the isobutylene monomers can smoothly coordinate with the metal center to further react, so that the polyisobutylene can be controlled to be linear, and the problem that the structure of the polyisobutylene prepared by using the existing catalyst is uncontrollable and the polyisobutylene is prone to forming a network polymer is solved. The pyridine tridentate ligand iron complex is used as the catalyst, the polymerization reaction rate is controllable, different molecular weight linear polyisobutylenes can be obtained by adjusting the specific type of the catalyst and the polymerization reaction time.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a pyridine-based tridentate ligand iron complex, its preparation method and application, and a method for preparing polyisobutylene. Background Technology

[0002] Polyisobutylene is a colorless, odorless, and non-toxic homopolymer of isobutylene, and its chemical structure is a typical linear saturated polymer. The main part of its molecular backbone consists of repeating units -CH2-C(CH3)2-, with a head of -CH3 and ends of -CH2-C(CH3)=CH2 or -CH=C(CH3)2. Due to differences in preparation methods and production processes, the molecular weight of polyisobutylene can vary within a wide range. Based on molecular weight, polyisobutylene can be classified into high molecular weight polyisobutylene (Mn>100000), medium molecular weight polyisobutylene (100000>Mn>10000), and low molecular weight polyisobutylene (Mn<10000).

[0003] Polyisobutylene (POI) possesses excellent properties such as resistance to acids, alkalis, water, salts, ozone, and aging, as well as good gas barrier properties and electrical insulation. It also exhibits good compatibility with asphalt, waxes, and polyethylene. Currently, the PPI industry has developed various polymerization methods to obtain PPI. From the perspective of catalysts, these methods can be divided into two categories: aluminum-based PPI (e.g., dichloroethylaluminum) and boron-based PPI. Essentially, these methods involve the formation of cations by aluminum or boron reagents in the reaction system, thereby inducing the polymerization of monomers.

[0004] During the aforementioned cationic-induced polymerization process, intramolecular rearrangement, transfer, and isomerization side reactions are prone to occur, making it difficult to control the structure and reaction rate of polyisobutylene. For example, when using dichloroethylaluminum as a catalyst to prepare polyisobutylene, experimental observations show that the reaction is very rapid, the reaction rate is uncontrollable, and the resulting polyisobutylene structure is often highly cross-linked (network polymer), insoluble, and its molecular weight cannot be measured. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a pyridine-based tridentate ligand iron complex, its preparation method and application, and a method for preparing polyisobutylene. The pyridine-based tridentate ligand iron complex provided by this invention, when used as a catalyst in the preparation of polyisobutylene, can better control the structure and reaction rate of polyisobutylene, yielding linear polyisobutylene with adjustable molecular weight.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a pyridine-based tridentate ligand iron complex having the structure shown in formula a or formula b:

[0008]

[0009] In equation a, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-; X is O or S;

[0010] In equation b, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-.

[0011] Preferably, formula a includes the structure shown in any one of Fe1 to Fe12:

[0012]

[0013] Formula b includes the structure shown in any one of the following Fe13 to Fe20:

[0014]

[0015] This invention provides a method for preparing the pyridine-based tridentate ligand iron complex described above, comprising the following steps:

[0016] Under the protection of a first inert gas, anhydrous FeCl3, a first organic solvent, and a pyridine tridentate ligand solution were mixed and complexed to obtain a pyridine tridentate ligand iron complex with the structure shown in formula a or formula b.

[0017] The pyridine tridentate ligand has the structure shown in formula c or formula d:

[0018]

[0019] In equation c, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-; X is O or S;

[0020] In formula d, R 1 R 2 and R 3Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-.

[0021] Preferably, formula c includes the structure shown in any one of the following 1 to 12:

[0022]

[0023] Formula d includes the structure shown in any of the following 13 to 20:

[0024]

[0025] Preferably, the molar ratio of pyridine tridentate ligands in the anhydrous FeCl3 and pyridine tridentate ligand solution is 1:1.05.

[0026] Preferably, the concentration of the pyridine-based tridentate ligand solution is 0.105 mol / L.

[0027] This invention provides the application of the pyridine-based tridentate ligand iron complex described in the above-described scheme or the pyridine-based tridentate ligand iron complex prepared by the above-described preparation method as a catalyst in the preparation of polyisobutylene.

[0028] This invention provides a method for preparing polyisobutylene, comprising the following steps:

[0029] Under the protection of a second inert gas, a co-catalyst solution, a pyridine-based tridentate ligand iron complex, isobutylene monomer, and a second organic solvent are mixed and subjected to a polymerization reaction to obtain the polyisobutylene; the pyridine-based tridentate ligand iron complex is the pyridine-based tridentate ligand iron complex described in the above scheme or the pyridine-based tridentate ligand iron complex prepared by the preparation method described in the above scheme.

[0030] Preferably, the co-catalyst solution is a toluene solution of the co-catalyst; the co-catalyst includes co-catalyst MAO, co-catalyst AlMe3, co-catalyst AlEt3, or co-catalyst Al i Bu3.

[0031] Preferably, the polymerization reaction is carried out at a temperature of -20 to 50°C for a time of 2 to 48 hours.

[0032] This invention provides a pyridine-based tridentate ligand iron complex having the structure shown in formula a or formula b:

[0033]

[0034] In equation a, R 1 R 2 and R3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-; X is O or S;

[0035] In equation b, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-.

[0036] The pyridine-based tripentate ligand iron complex provided by this invention has a conjugated framework. Different types of heteroatoms at the X position lead to a stronger electropositive charge on the iron center of the ferrous chloride complexed with the ligand, making it easier to activate the isobutylene monomer and thus improving reactivity. The nitrogen atom can also activate the isobutylene monomer, enhancing reactivity. Specifically, the lone pair electrons on the nitrogen atom coordinate with iron, giving the b-type complex a unique spatial structure. The isobutylene monomer can be activated by the central metallic iron in a specific direction, thereby promoting the polymerization reaction. The metal center does not easily coordinate with isobutylene, but the nitrogen atom can form a channel with a specific structure with ferric chloride, allowing for good coordination between isobutylene and iron.

[0037] The metal complex (pyridine-based tridentate ligand iron complex) provided by this invention has a complex spatial structure, which prevents isobutylene monomers from freely coordinating with the metal center and thus preventing the reaction. Only in the appropriate direction can isobutylene monomers successfully coordinate with the metal center and undergo polymerization. This allows the polyisobutylene to be controlled to have a linear structure, solving the problem that the polyisobutylene structure prepared by existing catalysts is uncontrollable and easily forms a network polymer (existing catalysts dichloroethylaluminum itself are highly active and can form active centers at any position, easily causing cross-linking within and between polyisobutylene chains, thus forming a network polymer).

[0038] This invention uses pyridine-based tridentate ligand iron complexes as catalysts, and the polymerization rate is controllable. By adjusting the specific type of catalyst and the polymerization time, linear polyisobutylenes of different molecular weights can be obtained.

[0039] Metallic iron (Fe) has unique physical properties, is inexpensive and highly reactive. When it complexes with pyridine-based tridentate ligands, it has a unique spatial structure that can effectively catalyze the polymerization of isobutylene.

[0040] The pyridine-based tridentate ligand iron complexes prepared by this invention are lower in cost and simpler to prepare compared to boron-based polyisobutylene catalysts. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 The GPC spectrum of the polyisobutylene prepared in Example 21;

[0043] Figure 2 The hydrogen spectrum of the polyisobutylene prepared in Example 21 is shown. Detailed Implementation

[0044] This invention provides a pyridine-based tridentate ligand iron complex having the structure shown in formula a or formula b:

[0045]

[0046] In equation a, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-; X is O or S;

[0047] In equation b, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-.

[0048] Unless otherwise specified, the materials and equipment of this invention are commercially available.

[0049] In this invention, formula a preferably includes the structure shown in any one of Fe1 to Fe12:

[0050]

[0051] In this invention, formula b preferably includes the structure shown in any one of Fe13 to Fe20:

[0052]

[0053] The pyridine-tridentate ligand iron complex provided by this invention has a conjugated structure for the entire framework of the pyridine-tridentate ligand. Different types of heteroatoms at the X position lead to a stronger positive charge on the iron center of the ferrous chloride complexed with the ligand, making it easier to activate the isobutylene monomer and thus improve the reactivity.

[0054] The metal complex (pyridine-based tridentate ligand iron complex) provided by this invention has a complex spatial structure, which prevents isobutylene monomers from freely coordinating with the metal center and thus from reacting. Only in the appropriate direction can isobutylene monomers successfully coordinate with the metal center and undergo polymerization. This allows the polyisobutylene to be controlled to have a linear structure, solving the problem that the polyisobutylene structure prepared by existing catalysts is uncontrollable and easily forms a network polymer.

[0055] This invention uses pyridine-based tridentate ligand iron complexes as catalysts, and the polymerization rate is controllable. By adjusting the specific type of catalyst and the polymerization time, linear polyisobutylenes of different molecular weights can be obtained.

[0056] Metallic iron (Fe) possesses unique physical properties, is inexpensive yet highly reactive, and when it complexes with pyridine-based tridentate ligands, it exhibits a unique spatial structure that can effectively catalyze the polymerization of isobutylene.

[0057] This invention provides a method for preparing the pyridine-based tridentate ligand iron complex described above, comprising the following steps:

[0058] Under the protection of a first inert gas, anhydrous FeCl3, a first organic solvent, and a pyridine tridentate ligand solution are mixed and complexed to obtain a pyridine tridentate ligand iron complex having the structure shown in formula a or b; wherein the pyridine tridentate ligand has the structure shown in formula c or d.

[0059]

[0060] In equation c, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、 t Bu-, F-, Cl-, Br-, OMe-, or Ph-; X is O or S;

[0061] In formula d, R 1 R 2 and R 3 Independently H-, Me-, CH3CH2-, CH3CH2CH2-, i Pr-、t Bu-, F-, Cl-, Br-, OMe-, or Ph-.

[0062] In this invention, the first inert gas preferably comprises argon. In this invention, the complexation is preferably carried out in a glove box.

[0063] In this invention, the mixing of anhydrous FeCl3, the first organic solvent, and the pyridine-based tridentate ligand solution preferably includes: mixing anhydrous FeCl3 and the first organic solvent, and then adding the pyridine-based tridentate ligand solution dropwise.

[0064] In this invention, the first organic solvent is preferably toluene. This invention does not have any particular requirements on the amount of the first organic solvent used; any amount well-known in the art can be used.

[0065] In this invention, the pyridine tridentate ligand solution is preferably obtained by dissolving the pyridine tridentate ligand in an organic solvent (denoted as the third organic solvent). In this invention, the third organic solvent preferably includes toluene.

[0066] In this invention, the molar ratio of pyridine tridentate ligands in the anhydrous FeCl3 and pyridine tridentate ligand solution is preferably 1:1.05; the concentration of the pyridine tridentate ligand solution is preferably 0.105 mol / L.

[0067] In this invention, the complexation temperature is preferably room temperature, and the time is preferably 48 hours.

[0068] After the complexation is completed, the present invention preferably filters the resulting reaction solution, washes the obtained solid three times with n-hexane, and dries it under vacuum to obtain the pyridine-based tripentate ligand iron complex. In the present invention, the filtration is preferably performed under an argon atmosphere.

[0069] In this invention, formula c preferably includes the structure shown in any one of the following 1 to 12:

[0070]

[0071] In this invention, formula d preferably includes the structure shown in any one of the following 13 to 20:

[0072]

[0073] In this invention, compounds 1 to 12 in formula c and compounds 13 to 20 in formula d are preferably obtained by purchase.

[0074] This invention provides the application of the pyridine-based tridentate ligand iron complex described in the above-described scheme or the pyridine-based tridentate ligand iron complex prepared by the above-described preparation method as a catalyst in the preparation of polyisobutylene.

[0075] This invention provides a method for preparing polyisobutylene, comprising the following steps:

[0076] Under the protection of a second inert gas, a co-catalyst solution, a pyridine-based tridentate ligand iron complex, isobutylene monomer, and a second organic solvent are mixed and subjected to a polymerization reaction to obtain the polyisobutylene; the pyridine-based tridentate ligand iron complex is the pyridine-based tridentate ligand iron complex described in the above scheme or the pyridine-based tridentate ligand iron complex prepared by the preparation method described in the above scheme.

[0077] In this invention, the second inert gas preferably comprises argon. In this invention, the second organic solvent preferably comprises toluene.

[0078] In this invention, the concentration of the co-catalyst solution is preferably 1.5 mol / L. In this invention, the co-catalyst solution is preferably a toluene solution of the co-catalyst; the co-catalyst preferably includes co-catalyst MAO, co-catalyst AlMe3, co-catalyst AlEt3, or co-catalyst Al. i Bu3.

[0079] In this invention, the molar amount of the pyridine-based tridentate ligand iron complex and the volume ratio of the second organic solvent are preferably 1 mol:(5-50) mL, more preferably 1 mol:(10-40) mL, and even more preferably 1 mol:(20-30) mL.

[0080] In this invention, the molar ratio of the pyridine-based tridentate ligand iron complex to the co-catalyst is preferably 1:(5-1000), more preferably 1:(20-500), and even more preferably 1:(40-400).

[0081] In this invention, the molar ratio of the pyridine-based tridentate ligand iron complex to the isobutylene monomer is preferably 1:50 to 1000, more preferably 1:(100 to 500), and even more preferably 1:(200 to 400).

[0082] In this invention, the temperature of the polymerization reaction is preferably -20 to 50°C, more preferably 5 to 40°C, and even more preferably 10 to 30°C. In this invention, the time of the polymerization reaction is preferably 2 to 48 hours, more preferably 5 to 40 hours, and even more preferably 10 to 30 hours.

[0083] To complete the polymerization reaction, the present invention preferably quenches the resulting reaction solution with methanol, and then washes, filters and dries it sequentially to obtain the polyisobutylene.

[0084] In this invention, the washing solvent is preferably methanol.

[0085] To further illustrate the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, describes a pyridine-based tridentate ligand iron complex, its preparation method and application, and a method for preparing polyisobutylene, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0086] Examples 1-12

[0087] In a glove box, anhydrous FeCl3 (1.0 equiv., 1 mmol) and toluene (8 mL) were added sequentially to a dry Schlenk tube (50 mL). Pyridine tridentate ligands 1–12 (1.05 equiv., 1.05 mmol) were dissolved in toluene (10 mL) and added dropwise to the FeCl3-containing Schlenk tube with stirring. The mixture was stirred at room temperature for 48 h. After the reaction was complete, the mixture was filtered under an argon atmosphere. The resulting solid was washed three times with n-hexane and dried under vacuum to obtain pyridine tridentate ligand iron complexes Fe1–Fe12, with yields of 96%, 90%, 76%, 98%, 88%, 93%, 75%, 85%, 93%, 95%, 80%, and 63%, respectively.

[0088] Examples 13-20

[0089] In a glove box, anhydrous FeCl3 (1.0 equiv., 1 mmol) and toluene (8 mL) were added sequentially to a dry Schlenk tube (50 mL). Pyridine tridentate ligands 13–20 (1.05 equiv., 1.05 mmol) were dissolved in toluene (10 mL) and added dropwise to the FeCl3-containing Schlenk tube with stirring. The mixture was stirred at room temperature for 48 h. After the reaction was complete, the mixture was filtered under an argon atmosphere. The resulting solid was washed three times with n-hexane and dried under vacuum to obtain pyridine tridentate ligand iron complexes Fe13–Fe20, with yields of 71%, 83%, 80%, 90%, 62%, 93%, 55%, and 88%, respectively.

[0090] Example 21

[0091] Under an argon atmosphere, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (0.5 mmol, 50 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0092] In this embodiment, the yield of low molecular weight polyisobutylene was 76%, the molecular weight was 125963 g / mol, and the PDI was 1.8.

[0093] Figure 1 The GPC spectrum of the polyisobutylene prepared in Example 21 is shown below. Figure 1 As shown, the single peak in polyisobutylene indicates that only one type of active center was formed during the polymerization process. The red peak represents light scattering, and the blue peak represents differential signal; both are methods of sample detection. The presence of these signals indicates that the sample has flowed out of the chromatography column and been detected by the detector. The GPC spectra of polyisobutylene obtained in Examples 22–58 are similar to those in Example 21.

[0094] Figure 2 The hydrogen spectrum of the polyisobutylene prepared in Example 21 is shown below. Figure 2 As shown, the peak with a chemical shift of 1.65 ppm represents two hydrogen atoms on the methylene group of the polyisobutylene molecular chain, and the peak with a chemical shift of 1.41 ppm represents two hydrogen atoms on the methyl group. The integral ratio is 1:2, which is consistent with the hydrogen atom arrangement on the polyisobutylene molecular chain.

[0095] Example 22

[0096] Under an argon atmosphere, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (1 mmol, 100 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0097] In this embodiment, the yield of low molecular weight polyisobutylene was 87%, the molecular weight was 196577 g / mol, and the PDI was 2.0.

[0098] Example 23

[0099] Under an argon atmosphere, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0100] In this embodiment, the yield of low molecular weight polyisobutylene was 93%, the molecular weight was 203359 g / mol, and the PDI was 2.2.

[0101] Example 24

[0102] Under an argon atmosphere, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst AlMe3 (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0103] In this embodiment, the yield of low molecular weight polyisobutylene was 62%, the molecular weight was 136469 g / mol, and the PDI was 2.2.

[0104] Example 25

[0105] Under an argon atmosphere, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst AlEt3 (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0106] In this embodiment, the yield of low molecular weight polyisobutylene was 51%, the molecular weight was 109527 g / mol, and the PDI was 2.8.

[0107] Example 26

[0108] Under an argon atmosphere, in a 25 mL Schlenk flask, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, and co-catalyst Al were added sequentially. i Bu3 (2 mmol, 200 equiv., 1.5 M toluene) and isobutylene (4 mmol, 400 equiv.) were reacted at 25 °C for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0109] In this embodiment, the yield of low molecular weight polyisobutylene was 50%, the molecular weight was 129321 g / mol, and the PDI was 1.8.

[0110] Comparative Example 1

[0111] Under an argon atmosphere, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was formed.

[0112] Comparative Example 2

[0113] Under an argon atmosphere, 5 mL of anhydrous toluene, MAO (2 mmol, 200 equiv., 1.5 M toluene solution) and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was formed.

[0114] Example 27

[0115] Under an argon atmosphere, Fe complex Fe2 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0116] In this embodiment, the yield of low molecular weight polyisobutylene was 83%, the molecular weight was 174560 g / mol, and the PDI was 2.0.

[0117] Example 28

[0118] Under an argon atmosphere, Fe complex Fe3 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0119] In this embodiment, the yield of low molecular weight polyisobutylene was 96%, the molecular weight was 166551 g / mol, and the PDI was 1.8.

[0120] Example 29

[0121] Under an argon atmosphere, Fe4 complex (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, MAO co-catalyst (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0122] In this embodiment, the yield of low molecular weight polyisobutylene was 86%, the molecular weight was 140933 g / mol, and the PDI was 2.3.

[0123] Example 30

[0124] Under an argon atmosphere, Fe complex Fe5 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0125] In this embodiment, the yield of low molecular weight polyisobutylene was 74%, the molecular weight was 169020 g / mol, and the PDI was 2.3.

[0126] Example 31

[0127] Under an argon atmosphere, Fe6 complex (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, MAO co-catalyst (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0128] In this embodiment, the yield of low molecular weight polyisobutylene was 90%, the molecular weight was 183572 g / mol, and the PDI was 2.2.

[0129] Example 32

[0130] Under an argon atmosphere, Fe7 complex (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, MAO co-catalyst (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0131] In this embodiment, the yield of low molecular weight polyisobutylene was 48%, the molecular weight was 230477 g / mol, and the PDI was 2.0.

[0132] Example 33

[0133] Under an argon atmosphere, Fe complex Fe8 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0134] In this embodiment, the yield of low molecular weight polyisobutylene was 95%, the molecular weight was 157527 g / mol, and the PDI was 2.6.

[0135] Example 34

[0136] Under an argon atmosphere, Fe9 complex (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, MAO co-catalyst (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0137] In this embodiment, the yield of low molecular weight polyisobutylene was 80%, the molecular weight was 169627 g / mol, and the PDI was 2.6.

[0138] Example 35

[0139] Under an argon atmosphere, Fe complex Fe10 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0140] In this embodiment, the yield of low molecular weight polyisobutylene was 65%, the molecular weight was 183527 g / mol, and the PDI was 3.0.

[0141] Example 36

[0142] Under an argon atmosphere, Fe complex Fe11 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0143] In this embodiment, the yield of low molecular weight polyisobutylene was 71%, the molecular weight was 130527 g / mol, and the PDI was 2.3.

[0144] Example 37

[0145] Under an argon atmosphere, Fe complex Fe12 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0146] In this embodiment, the yield of low molecular weight polyisobutylene was 74%, the molecular weight was 117927 g / mol, and the PDI was 2.3.

[0147] Examples 38-41

[0148] Under an argon atmosphere, Fe complex Fe1 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 2 h, 4 h, 8 h, and 16 h, respectively. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0149] Examples 38-41 show low molecular weight polyisobutylene yields of 42%, 60%, 83%, and 95%, with molecular weights of 60634 g / mol, 85699 g / mol, 179542 g / mol, and 218620 g / mol, and PDI values ​​of 2.1, 2.6, 2.4, and 2.5, respectively.

[0150] Example 42

[0151] Under an argon atmosphere, Fe complex Fe13 (10 μmol, 1 equiv.) and 5 mL of anhydrous toluene, co-catalyst MAO (0.5 mmol, 50 equiv., 1.5 M toluene solution) and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0152] In this embodiment, the yield of low molecular weight polyisobutylene was 45%, the molecular weight was 223698 g / mol, and the PDI was 1.8.

[0153] Example 43

[0154] Under an argon atmosphere, Fe complex Fe13 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (1 mmol, 100 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0155] In this embodiment, the yield of low molecular weight polyisobutylene was 68%, the molecular weight was 196577 g / mol, and the PDI was 2.0.

[0156] Example 44

[0157] Under an argon atmosphere, Fe complex Fe13 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0158] In this embodiment, the yield of low molecular weight polyisobutylene was 92%, the molecular weight was 168532 g / mol, and the PDI was 2.1.

[0159] Example 45

[0160] Under an argon atmosphere, Fe complex Fe13 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst AlMe3 (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0161] In this embodiment, the yield of low molecular weight polyisobutylene was 85%, the molecular weight was 132569 g / mol, and the PDI was 2.2.

[0162] Example 46

[0163] Under an argon atmosphere, Fe complex Fe13 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst AlEt3 (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0164] In this embodiment, the yield of low molecular weight polyisobutylene was 80%, the molecular weight was 113527 g / mol, and the PDI was 2.7.

[0165] Example 47

[0166] Under an argon atmosphere, in a 25 mL Schlenk flask, Fe complex Fe13 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, and co-catalyst Al were added sequentially. iBu3 (2 mmol, 200 equiv., 1.5 M toluene) and isobutylene (4 mmol, 400 equiv.) were reacted at 25 °C for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0167] In this embodiment, the yield of low molecular weight polyisobutylene was 77%, the molecular weight was 109521 g / mol, and the PDI was 1.8.

[0168] Comparative Example 3

[0169] Under an argon atmosphere, Fe complex Fe13 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was formed.

[0170] Comparative Example 4

[0171] Under an argon atmosphere, anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was formed.

[0172] Example 48

[0173] Under an argon atmosphere, Fe complex Fe14 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0174] In this embodiment, the yield of low molecular weight polyisobutylene was 90%, the molecular weight was 186551 g / mol, and the PDI was 1.7.

[0175] Example 49

[0176] Under an argon atmosphere, Fe complex Fe15 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0177] In this embodiment, the yield of low molecular weight polyisobutylene was 90%, the molecular weight was 186551 g / mol, and the PDI was 1.7.

[0178] Example 50

[0179] Under an argon atmosphere, Fe complex Fe16 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0180] In this embodiment, the yield of low molecular weight polyisobutylene was 95%, the molecular weight was 161931 g / mol, and the PDI was 2.3.

[0181] Example 51

[0182] Under an argon atmosphere, Fe complex Fe17 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene.

[0183] In this embodiment, the yield of low molecular weight polyisobutylene was 94%, the molecular weight was 169920 g / mol, and the PDI was 2.3.

[0184] Example 52

[0185] Under an argon atmosphere, Fe complex Fe18 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0186] In this embodiment, the yield of low molecular weight polyisobutylene was 90%, the molecular weight was 183572 g / mol, and the PDI was 2.2.

[0187] Example 53

[0188] Under an argon atmosphere, Fe complex Fe19 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0189] In this embodiment, the yield of low molecular weight polyisobutylene was 98%, the molecular weight was 202469 g / mol, and the PDI was 2.5.

[0190] Example 54

[0191] Under an argon atmosphere, Fe complex Fe2O (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0192] In this embodiment, the yield of low molecular weight polyisobutylene was 85%, the molecular weight was 169527 g / mol, and the PDI was 2.2.

[0193] Examples 55-58

[0194] Under an argon atmosphere, Fe complex Fe13 (10 μmol, 1 equiv.), 5 mL of anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 2 h, 4 h, 8 h, and 16 h, respectively. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely polyisobutylene.

[0195] Examples 55-58 show low molecular weight polyisobutylene yields of 20%, 56%, 80%, and 93%, respectively, with molecular weights of 119634 g / mol, 135699 g / mol, 178532 g / mol, and 196620 g / mol, and PDI values ​​of 2.1, 2.7, 2.4, and 2.5, respectively.

[0196] Comparative Example 5

[0197] Under an argon atmosphere, anhydrous toluene (5 mL), co-catalyst dichloroethylaluminum (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was reacted at 25 °C for 12 h, quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a white powdered polymer, namely polyisobutylene, with a yield >99%. In this example, the polyisobutylene is a highly cross-linked polymer that cannot be dissolved or characterized.

[0198] In summary, this invention uses pyridine-based tridentate ligand iron complexes as catalysts, allowing for controllable polymerization rates. By adjusting the specific type of catalyst and the polymerization time, linear polyisobutylenes of different molecular weights can be obtained.

[0199] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing polyisobutylene, characterized in that, Includes the following steps: Under an argon atmosphere, 10 μmol of Fe complex Fe3, 5 mL of anhydrous toluene, MAO toluene solution (containing 2 mmol of MAO at a concentration of 1.5 M), and 4 mmol of isobutylene were added sequentially to a 25 mL Schlenk flask. The system was reacted at 25 °C for 12 h, quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain polyisobutylene. The yield of low molecular weight polyisobutylene was 96%, with a molecular weight of 166551 g / mol and a PDI of 1.

8. 。 2. The preparation method according to claim 1, characterized in that, The preparation method of the Fe complex Fe3 includes the following steps: Under the protection of a first inert gas, anhydrous FeCl3, a first organic solvent, and a pyridine tridentate ligand solution were mixed and complexed to obtain the Fe complex Fe3. The pyridine-based tridentate ligand has the structure shown in formula c; The structure of formula c is: 。 3. The preparation method according to claim 2, characterized in that, The molar ratio of pyridine tridentate ligands in the anhydrous FeCl3 and pyridine tridentate ligand solution is 1:1.

05.

4. The preparation method according to claim 2, characterized in that, The concentration of the pyridine tridentate ligand solution is 0.105 mol / L.

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