An alkylaluminum compound, a rare earth catalyst composition configured therefrom, and use in the preparation of di-terminally functionalized rubbers

Abstract

This invention discloses a functionalized alkylaluminum compound, a functionalized rare earth catalyst composition thereof, and its application in the preparation of bifunctionalized rubber. The functionalized alkylaluminum compound is an alkylaluminum compound with an amino polar group. This compound can be controllably prepared by living anionic polymerization, exhibiting flexibility and high efficiency. The functionalized rare earth catalyst composition thereof can be applied to the preparation of bifunctionalized rubber. This rare earth catalyst composition consists of a rare earth metal compound, a functionalized alkylaluminum compound, and a chlorine source in a molar ratio of 1:(10-30):(0-5.0). This catalytic system can efficiently catalyze the polymerization of conjugated olefins to obtain narrowly distributed stereoregular rubber with initiator-terminal functionalization. The functionalization efficiency can reach 95%, the stereoregularity of cis-diolefins can reach 96%, and the molecular weight distribution is below 2.5.

Description

Technical Field

[0001] This invention relates to the field of catalysts for the preparation of rare earth rubber, including a functionalized alkylaluminum compound, a configured functionalized rare earth catalyst composition, and its application in the preparation of bifunctionalized rubber. Background Technology

[0002] Rare earth rubber, a high-cis polydiolefin produced using rare earth compounds as catalysts, exhibits excellent flexural strength, abrasion resistance, and low rolling resistance, making it a promising candidate for tire manufacturing. However, due to differences in polarity, the rubber matrix suffers from poor compatibility with reinforcing fillers, becoming a major factor affecting its performance. Therefore, developing end-functionalized rare earth rubber is of great significance for the preparation of high-performance tires.

[0003] Rare earth rubber polymer chains consist of an initiator end and a terminator end. Termination-terminated functionalized rare earth rubbers can be conveniently prepared by end-capping reactions using coordination chain transfer living polymerization with quasi-active characteristics. For example, the Visseaux group used benzophenone to end-cap a neodymium-catalyzed isoprene system, obtaining a stereoregular polymer with terminal hydroxyl groups (Macromolecules 2019, 52, 1210–1219); the Mecking group used tetraethyl orthosilicate to end-cap a neodymium-catalyzed isoprene polymerization system, obtaining a stereoregular rubber with terminal siloxy groups (Macromolecules 2018, 51, 763–770). However, these methods suffer from low end-capping efficiency and high residual small molecule content, resulting in poor mechanical properties of the rubber. Functionalized initiation systems can conveniently prepare initiator-terminated functionalized rare earth rubbers. For example, the Mecking group used functionalized alkylaluminum compounds in a rare-earth neodymium metal catalytic system to prepare a series of cis-butadiene rubbers with amino groups at the end groups. However, the preparation methods for these functionalized alkylaluminum compounds are cumbersome and expensive. These methods are characterized by high activity, meaning that functionalized initiators can be efficiently introduced to the polymer chain ends. However, these methods require the preparation of expensive and difficult-to-prepare functionalized initiators.

[0004] Against this backdrop, in order to prepare high-performance dual-functionalized rare earth rubber and solve the problem of poor compatibility between non-traditional rubbers and polar fillers during use, this invention provides an amino-functionalized rare earth catalyst composition based on functionalized alkyl aluminum. This composition can efficiently initiate the (co)polymerization of butadiene and isoprene, and combined with a capping system, it can prepare dual-functionalized rare earth rubber with polar groups at both the initiation and termination ends. Summary of the Invention

[0005] The problem this invention aims to solve is overcoming the poor compatibility between rare earth rubber and reinforcing fillers. Based on a novel amine-functionalized rare earth catalyst composition, it provides an efficient method for preparing end-functionalized rare earth rubber. This method differs from traditional end-capping methods, efficiently introducing amine functional groups into the initiation ends of rubber molecular chains. The resulting product exhibits uniform structure and no small-molecule additive residues. Introducing amine groups into the rubber chain ends facilitates nano-dispersion of fillers within the rubber matrix. Simultaneously, the groups at the rubber molecular chain ends interact with the oxygen-containing functional groups on the surface of the reinforcing filler during processing, forming hydrogen bonds or ionic bonds. This improves filler dispersibility and interfacial strength while also passivating the movement of the rubber molecular chain ends, thereby reducing energy consumption and rolling resistance during the deformation process of rare earth butyl pentadiene rubber.

[0006] This invention provides a functionalized alkylaluminum compound, wherein the alkylaluminum compound is an alkylaluminum compound having an amino polar group, and its structure is AlR1(R2)2, wherein R1 is selected from one of the following I-XII structural formulas, wherein R′ is an alkyl group, selected from n-butyl, sec-butyl, tert-butyl, preferably n-butyl; x takes the value of 1-20, preferably 1-10; m takes the value of 5-20, preferably 5-10; n takes the value of 5-20, preferably 5-10; and R2 is selected from one of ethyl, isobutyl, n-butyl, and octyl structures.

[0007]

[0008] The above-mentioned functionalized alkylaluminum compounds were prepared by anionic polymerization.

[0009] When R1 in AlR1(R2)2 is structural formula I-VI, its preparation method is as follows:

[0010] The specific synthesis method is as follows:

[0011] (1) Dissolve 1-(4-dimethylaminophenyl)-1'-phenylethylene or bis(1,1'-(4-dimethylaminophenyl)ethylene) in a nonpolar solvent. The concentration of the solute (1-(4-dimethylaminophenyl)-1'-phenylethylene or bis(1,1'-(4-dimethylaminophenyl)ethylene) is 5-30 g / L, preferably 10-20 g / L. The nonpolar solvent is n-hexane, hexane, toluene, or benzene, preferably cyclohexane. Alkyl lithium is added to the obtained solution. 1-(4-dimethylaminophenyl)-1'-phenylethylene or bis(1,1'-(4-dimethylaminophenyl)ethylene) is reacted with the alkyl lithium at 0-50 degrees Celsius for 10-120 minutes, preferably at 50 degrees Celsius for 30 minutes. The alkyl lithium can be n-butyllithium, sec-butyllithium, or tert-butyllithium, preferably sec-butyllithium. The molar ratio of 1-(4-dimethylaminophenyl)-1'-phenylethylene or bis(1,1'-(4-dimethylaminophenyl)ethylene) to alkyl lithium is in the range of 1-20:1, preferably 1-5:1.

[0012] (2) Add a diene monomer to the solution obtained in step (1) and act at 0-50 degrees Celsius for 10-120 minutes, preferably at 50 degrees Celsius for 60 minutes; the diene monomer is selected from one or two of butadiene and isoprene, and the molar ratio of diene monomer to alkyl lithium is 10-40:1, preferably 10-20:1.

[0013] (3) The solution obtained in step (2) is then mixed with the alkyl aluminum chloride compound and reacted at 0-50 degrees Celsius for 0-30 minutes, preferably at 50 degrees Celsius for 10 minutes. The alkyl aluminum chloride compound is selected from diethylaluminum chloride, diisobutylaluminum chloride, sesquialuminum chloride, and dioctylaluminum chloride, preferably diisobutylaluminum chloride. The molar ratio of the added alkyl aluminum chloride compound to alkyl lithium is 1.00-1.20:1 based on the chlorine content. The prepared functionalized alkyl aluminum compound is directly used in the preparation of functionalized rare earth catalyst compositions.

[0014] When R1 in AlR1(R2)2 has structural formulas VII-IX, its preparation method is as follows:

[0015]

[0016] The specific synthesis method is as follows:

[0017] (1) Dissolve 4-dimethylaminostyrene and diene monomers in a nonpolar solvent. The molar ratio of 4-dimethylaminostyrene to diene monomers is in the range of 1:5-20, preferably 1:10. The concentration of the solute 4-dimethylaminostyrene and diene monomers is 5-30 g / L, preferably 10-20 g / L. The nonpolar solvent is n-hexane, hexane, toluene, or benzene, preferably cyclohexane. Then, add alkyllithium to the resulting solution. The 4-dimethylaminostyrene and diene monomers react with the alkyllithium at 0-50°C for 60-240 minutes, preferably 50°C for 120 minutes. The alkyllithium can be n-butyllithium, sec-butyllithium, or tert-butyllithium, preferably sec-butyllithium. The molar ratio of 4-dimethylaminostyrene to alkyllithium is in the range of 1-20:1, preferably 1-5:1. The diene monomer is selected from one or two of butadiene and isoprene, and the molar ratio of diene monomer to alkyl lithium is in the range of 10-40:1, preferably 10-20:1.

[0018] (2) The solution obtained in step (1) is then mixed with the alkyl aluminum chloride compound and reacted at 0-50 degrees Celsius for 0-30 minutes, preferably at 50 degrees Celsius for 10 minutes. The alkyl aluminum chloride compound is selected from diethylaluminum chloride, diisobutylaluminum chloride, sesquialuminum chloride, and dioctylaluminum chloride, preferably diisobutylaluminum chloride. The molar ratio of the added alkyl aluminum chloride compound to alkyl lithium is 1.00-1.20:1 based on the chlorine content. The prepared functionalized alkyl aluminum compound is directly used in the preparation of functionalized rare earth catalyst compositions.

[0019] When R1 in AlR1(R2)2 is of structural formula X-XII, its preparation method is as follows:

[0020]

[0021] The specific synthesis method is as follows:

[0022] (1) Dissolve hexamethyleneimine in a nonpolar solvent. The concentration of hexamethyleneimine is 5-30 g / L, preferably 10-20 g / L. The nonpolar solvent is n-hexane, hexane, toluene, or benzene, preferably cyclohexane. Add alkyl lithium to the resulting solution. The molar ratio of hexamethyleneimine to alkyl lithium is 1-1.05:1, preferably 1.05:1. The hexamethyleneimine and alkyl lithium are reacted at 0-50 degrees Celsius for 10-120 minutes, preferably at 25 degrees Celsius for 30 minutes. The alkyl lithium can be n-butyllithium, sec-butyllithium, or tert-butyllithium, preferably n-butyllithium.

[0023] (2) Then, add the diene monomer to the solution obtained in step (1) and react it at 0-50 degrees Celsius for 10-120 minutes, preferably at 50 degrees Celsius for 60 minutes. The diene monomer is selected from one or two of butadiene and isoprene, and the molar ratio of diene monomer to alkyl lithium is in the range of 1-40:1, preferably 10-20:1.

[0024] (3) The solution obtained in step (2) is then mixed with the alkyl aluminum chloride compound and reacted at 0-50 degrees Celsius for 0-30 minutes, preferably at 50 degrees Celsius for 10 minutes. The alkyl aluminum chloride compound is selected from diethylaluminum chloride, diisobutylaluminum chloride, sesquialuminum chloride, and dioctylaluminum chloride, preferably diisobutylaluminum chloride. The molar ratio of the added alkyl aluminum chloride compound to alkyl lithium is 1.00-1.20:1 based on the chlorine content. The prepared functionalized alkyl aluminum compound is directly used in the preparation of functionalized rare earth catalyst compositions.

[0025] This invention also provides a functionalized rare earth catalyst composition, which is composed of a rare earth metal compound, a functionalized alkyl aluminum compound, and a chlorine source in a molar ratio of 1:(10-30):(0-5), preferably 1:(10-15):(0-3). The functionalized alkyl aluminum compound in the composition is the alkyl aluminum compound with an amino functionalized group prepared above. The rare earth metal element in the rare earth metal compound is neodymium, specifically neodymium neodecanoate, neodymium naphthenate, or neodymium isopropoxy, preferably neodymium neodecanoate. The chlorine source is selected from dichlorodimethylsilane, silicon tetrachloride, tert-butyl chloride, diisobutylaluminum chloride, diethylaluminum chloride, ethylaluminum dichloride, and ethyl sesquichloride, preferably diethylaluminum chloride.

[0026] The present invention also provides a method for preparing a functionalized rare earth catalyst composition, the method comprising: contacting a functionalized alkyl aluminum compound, a chlorine source and a rare earth compound in a nonpolar solvent under an inert gas protection.

[0027] The mixing order of the three components—rare earth compound, functionalized alkyl aluminum compound, and chlorine source—is as follows: (1) the functionalized alkyl aluminum compound is contacted with the chlorine source and then with the rare earth compound; (2) the chlorine source, functionalized alkyl aluminum compound, and rare earth compound are contacted in sequence; (3) the rare earth compound, functionalized alkyl aluminum compound, and chlorine source are contacted in sequence.

[0028] The inert gas is nitrogen or argon, preferably high-purity nitrogen or high-purity argon, and more preferably high-purity argon; the non-polar solvent includes hexane, cyclohexane, raffinate, toluene, and benzene, preferably cyclohexane and hexane; the concentration of rare earth elements in the functionalized rare earth catalyst composition ranges from 5 to 30 mmol / L, preferably 10 to 20 mmol / L; the contact conditions include a temperature of 0 to 50 degrees Celsius, preferably 50 degrees Celsius, and a time of 0 to 360 minutes, preferably 0 to 60 minutes.

[0029] This invention also provides a polymerization method for bifunctionalized rare earth rubber, comprising: contacting a conjugated diene with a functionalized rare earth catalyst composition in a nonpolar solvent; after polymerization for a certain time, adding a capping agent to contact the synthesized polymer solution and terminating the reaction; wherein the functionalized rare earth catalyst composition is any of the functionalized rare earth catalyst compositions prepared above; wherein the conjugated diene is selected from one or both of butadiene and isoprene; the molar ratio of the conjugated diene to the functionalized rare earth catalyst composition based on rare earth metal elements is 1000-20000:1, preferably 5000-15000; the nonpolar solvent includes hexane, cyclohexane, raffinate oil, toluene, and benzene, preferably cyclohexane and hexane. The polymerization reaction conditions include: a temperature of 0°C to 60°C, preferably 60°C, and a time of 1-5 hours, preferably 2-4 hours.

[0030] The end-capping agent mentioned in the polymerization method of the above-mentioned dual-functionalized rare earth rubber can be any one of the following:

[0031] Benzophenone derivatives, including benzophenone, 4-(dimethylamino)benzophenone, 4-(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, and 4,4'-bis(diethylamino)benzophenone;

[0032] Isocyanate derivatives, including cyclohexyl isocyanate, octadecyl isocyanate, p-toluene isocyanate, tert-butyl isocyanate, and dodecyl isocyanate;

[0033] Oxygen-containing compounds, including hydrogen peroxide and oxygen.

[0034] Beneficial effects of this invention:

[0035] The functionalized alkylaluminum compounds disclosed in this invention have amino functionalized groups and can be controlledly prepared based on a living anionic polymerization method. This method is simple, flexible and efficient. The prepared functionalized alkylaluminum compounds have high reactivity and strong controllability, and can prepare functionalized alkylaluminum compounds with different structures to meet the catalyst configuration requirements. The functionalized alkylaluminum compound disclosed in this invention is a compound with an amino functionalized group. This functionalized alkylaluminum compound can be prepared into a functionalized homogeneous catalyst after contacting with rare earth compounds and chlorine sources. This catalytic system can efficiently catalyze the polymerization of conjugated olefins and can obtain a narrow-distribution stereoregular rubber with initiating end-functionalized end groups. The functionalization efficiency can reach 95%, the stereoregularity of cis-diolefins can reach 96%, and the molecular weight distribution is less than 2.5. The amino groups have little effect on the activity of the catalytic system in the rare earth catalytic initiation system. The end-functionalized rare earth cis-butadiene rubber solves the problem of (1) poor compatibility between the rubber matrix and polar fillers, which greatly improves the mechanical properties of the rubber; (2) the problem of free movement of the rubber end, which greatly reduces the hysteresis loss during the use of the rubber. Attached Figure Description

[0036] Figure 1 NMR spectrum of amino-functionalized alkyl aluminum obtained in Example 1;

[0037] Figure 2 The chromatogram of the amino-functionalized alkylaluminum gel permeation obtained in Example 1;

[0038] Figure 3 NMR spectrum of the sample obtained in Example 9 (initiator-terminal functionalization);

[0039] Figure 4 NMR spectrum of the sample obtained in Example 10 (initiator / termination functionalization);

[0040] Figure 5 NMR spectrum of the sample obtained in Example 11 (initiator / termination end functionalization);

[0041] Figure 6 NMR spectrum of the sample obtained in Example 12 (initiator / termination functionalization). Detailed Implementation

[0042] The present invention provides the following embodiments as further illustrations, but these are not intended to limit the scope of protection of the claims. The molecular weight and molecular weight distribution index (weight-average molecular weight to number-average molecular weight) of the polymer were determined by gel permeation chromatography (SEC), and the cis-trans isomer content in the polymer was determined by Fourier transform infrared spectroscopy. The ampoules mentioned in the embodiments were all baked at high temperature and vacuum dried before use, and all operations in the embodiments were performed under the protection of high-purity argon (99.999%).

[0043] Examples 1-8 illustrate the preparation of amino-functionalized alkylaluminum compounds.

[0044] Example 1

[0045] 1-(4-dimethylaminophenyl)-1'-phenylethylene (0.23 g) and 9 mL of dry cyclohexane were added sequentially to a 20 mL ampoule, followed by 0.9 mL of a 1.13 M solution of sec-butyllithium in n-hexane. The reaction was carried out at 25 °C for 30 minutes, then 2 mL of isoprene was added, followed by a reaction at 50 °C for 4 hours. Finally, a 1.7 mL solution of diisobutylaluminum chloride in hexane (0.6 M) was added, and the reaction was carried out at room temperature for 30 minutes to obtain amino-functionalized alkylaluminum reagent 1. Its structure was characterized by 1H NMR and gel permeation chromatography as follows: Figure 1 , 2 As shown.

[0046] Example 2

[0047] 1-(4-dimethylaminophenyl)-1'-phenylethylene (0.27 g) and 9 mL of dry cyclohexane were added sequentially to a 20 mL ampoule, followed by 0.9 mL of sec-butyllithium in n-hexane (1.13 M). After reacting at 50 °C for 30 min, 1 mL of isoprene was added, and the reaction was continued at 50 °C for 4 h. Then, a hexane solution of diisobutylaluminum chloride (0.6 M, 1.7 mL) was added, and the reaction was continued at room temperature for 30 min to obtain amino-functionalized alkylaluminum reagent 2.

[0048] Example 3

[0049] 4-Dimethylaminostyrene (1.47 g) and cyclohexane solution of succinate (9 mL, 1.11 M succinate) were added sequentially to a 20 mL ampoule, followed by 0.9 mL of n-hexane solution of sec-butyllithium (1.13 M). The mixture was reacted at 50 °C for 4 hours, and then 1.0 mL of hexane solution of diethylaluminum chloride (1.0 M 1.0 mL) was added. The mixture was reacted at room temperature for 30 minutes to obtain amino-functionalized alkylaluminum reagent 3.

[0050] Example 4

[0051] Hexamethyleneimine (0.14 g) and 9 mL of dry cyclohexane were added sequentially to a 20 mL ampoule, followed by 0.9 mL of a 1.13 M solution of sec-butyllithium in n-hexane. The mixture was reacted at room temperature for 2 hours. Then, 2 mL of a mixed solution of butadiene and isoprene (0.27 g butadiene, 0.34 g isoprene, cyclohexane) was added, and the mixture was reacted at 50 °C for 4 hours. Finally, a 1.0 mL solution of diethylaluminum chloride in hexane (1.0 M) was added, and the mixture was reacted at room temperature for 30 minutes to obtain amino-functionalized alkylaluminum reagent 4.

[0052] Example 5

[0053] 1,1'-(4-dimethylaminophenyl)ethylene (0.27 g) and 9 mL of dry cyclohexane were added sequentially to a 20 mL ampoule, followed by 0.67 mL of n-butyllithium in n-hexane (1.60 M). After reacting at 0 °C for 120 min, 2 mL of isoprene was added, and the reaction was continued at 0 °C for 2 h. Then, a hexane solution of diisobutylaluminum chloride (0.6 M, 1.7 mL) was added, and the reaction was continued at room temperature for 0 min to obtain amino-functionalized alkylaluminum reagent 5.

[0054] Example 6

[0055] 1,1'-(4-dimethylaminophenyl)ethylene (0.27 g) and 9 mL of dry cyclohexane were added sequentially to a 20 mL ampoule, followed by 0.67 mL of a 1.60 M solution of n-butyllithium in n-hexane. After reacting at 50 °C for 10 minutes, 2 mL of a mixed solution of butadiene and isoprene (0.27 g butadiene, 0.34 g isoprene, cyclohexane as solvent) was added, and the reaction was continued at 50 °C for 2 hours. Then, a 1.7 mL solution of 0.6 M dioctylaluminum in hexane was added, and the reaction was continued at room temperature for 30 minutes to obtain amino-functionalized alkylaluminum reagent 6.

[0056] Example 7

[0057] 4-Dimethylaminostyrene (1.47 g) and isoprene in cyclohexane (9 mL, isoprene concentration 1.40 M) were added sequentially to a 20 mL ampoule, followed by 0.9 mL of n-butyllithium in n-hexane (1.60 M). The mixture was reacted at 50 °C for 4 hours, and then diethylaluminum chloride in hexane (1.0 M, 1.0 mL) was added. The mixture was reacted at room temperature for 30 minutes to obtain amino-functionalized alkylaluminum reagent 7.

[0058] Example 8

[0059] Hexamethyleneimine (0.14 g) and 9 mL of dry cyclohexane were added sequentially to a 20 mL ampoule, followed by 0.9 mL of sec-butyllithium in n-hexane (1.13 M). The mixture was reacted at room temperature for 2 hours, then 9 mL of isoprene in cyclohexane (1.40 M isoprene) was added, and the mixture was reacted at 50 °C for 4 hours. Finally, 1.0 mL of diethylaluminum chloride in hexane (1.0 M) was added, and the mixture was reacted at room temperature for 30 minutes to obtain amino-functionalized alkylaluminum reagent 8.

[0060] Examples 9-25 illustrate the preparation of rare earth catalyst compositions based on amino-functionalized alkylaluminum 1-8 and their application in diolefin polymerization.

[0061] Example 9

[0062] To 1.3 mL of amine-functionalized alkyl aluminum reagent 1 (0.08 M), 0.2 mL of a hexane solution of diisobutylaluminum chloride (0.05 M) was added. After preheating at 50 °C for 10 minutes, 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) was added, and the mixture was kept at 50 °C for 30 minutes. Immediately afterwards, 1.0 mL of isoprene was added, and polymerization was carried out at 50 °C for 2.5 hours. Anhydrous ethanol was then added to terminate the polymerization. Gel permeation chromatography showed that the molecular weight of the obtained polymer was 11.5 kg / mol, the molecular weight distribution was 1.1, and the cis content was 87.0% as indicated by carbon NMR. Hydrogen NMR showed that the terminal amine functionalization (initiation end) efficiency was 95.0%.

[0063] Example 10

[0064] To 1.9 mL of amine-functionalized alkylaluminum reagent 1 (0.08 M), 0.3 mL of a hexane solution of diisobutylaluminum chloride (0.05 M) was added. After preheating at 50 °C for 10 minutes, 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) was added, and the mixture was kept at 50 °C for 30 minutes. Immediately afterwards, 2.5 mL of isoprene was added, and polymerization was carried out at 50 °C for 3.5 hours. Then, 2.0 g of dodecyl isocyanate was added to terminate the polymerization. Gel permeation chromatography (GPC) characterization showed that the polymer had a molecular weight of 7.8 kg / mol and a molecular weight distribution of 1.04. Carbon NMR characterization showed that the cis content was 90.7%. Hydrogen NMR characterization showed that the initiation-terminal functionalization efficiency was 95.0%, and the termination-terminal functionalization efficiency was 91%.

[0065] Example 11

[0066] Add 0.1 mL of a hexane solution of diisobutylaluminum chloride (0.05 M) to 0.9 mL of amino-functionalized alkylaluminum reagent 1 (0.08 M). Preheat at 50 °C for 10 minutes, then add 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) and maintain for 120 minutes. Immediately afterwards, add 3.4 g of isoprene. After polymerization at 50 °C for 1.5 hours, add 1.0 g of 4-dimethylaminobenzophenone. Gel permeation chromatography characterization shows the polymer has a molecular weight of 12.4 kg / mol and a molecular weight distribution of 1.20. Carbon NMR characterization shows a cis content of 94.7%. Hydrogen NMR characterization shows an initiation-terminal functionalization efficiency of 91.0% and a termination-terminal functionalization efficiency of 82.0%.

[0067] Example 12

[0068] 0.6 mL of amino-functionalized alkylaluminum reagent 1 (0.08 M) was preheated at 50 °C for 10 minutes, followed by the addition of 0.05 mL of neodymium neodecanoate in hexane (0.1 M), and maintained for 60 minutes. Immediately afterwards, 0.4 mL of isoprene was added, and polymerization was carried out at 50 °C for 1.5 hours. Then, 5 mL of hydrogen peroxide (30 wt.%) was added, followed by 5 mL of sodium hydroxide aqueous solution (10 wt.%). Gel permeation chromatography characterization showed that the polymer had a molecular weight of 6.3 kg / mol and a molecular weight distribution of 1.05. Carbon NMR characterization showed a cis content of 85.0%. Hydrogen NMR characterization showed an initiation-terminal functionalization efficiency of 95.0% and a termination-terminal functionalization efficiency of 82.0%.

[0069] Example 13

[0070] To 1.3 mL of amine-functionalized alkyl aluminum reagent 1 (0.08 M), 0.4 mL of a hexane solution of diisobutylaluminum chloride (0.05 M) was added. After preheating at 0 °C for 10 min, 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) was added, and the mixture was maintained for 180 min. Immediately afterwards, 1.4 g of isoprene and 40 mL of butadiene hexane solution (2.0 M) were added. Polymerization was carried out at 60 °C for 5.0 hours, and then terminated with ethanol. Gel permeation chromatography characterization showed that the molecular weight of the obtained polymer was 23.5 kg / mol, the molecular weight distribution was 1.30, and the cis content was 98.7% as indicated by carbon NMR. 1H NMR characterization showed that the initiation-terminal functionalization efficiency was 94.3% and the termination-terminal functionalization efficiency was 83.5%.

[0071] Example 14

[0072] To 1.9 mL of amine-functionalized alkylaluminum reagent 2 (0.08 M), 0.2 mL of a hexane solution of diethylaluminum chloride (0.05 M) was added. After preheating at 30 °C for 10 minutes, 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) was added, and the mixture was maintained for 240 minutes. Immediately afterwards, 75 mL of a hexane solution of butadiene (2.0 M) was added. Polymerization was carried out at 30 °C for 4.5 hours, and 2.0 g of dodecyl isocyanate was added to terminate the polymerization. Gel permeation chromatography characterization showed that the molecular weight of the obtained polymer was 43.2 kg / mol, the molecular weight distribution was 1.40, and the cis content was 99.6% as indicated by carbon NMR. 1H NMR characterization showed that the initiation-terminal functionalization efficiency was 95.3% and the termination-terminal functionalization efficiency was 92.4%.

[0073] Example 15

[0074] Add 0.15 mL of ethyl sesquichloride in hexane (0.05 M) to 0.6 mL of amino-functionalized alkyl aluminum reagent 3 (0.08 M). Preheat at 30 °C for 10 minutes, then add 0.05 mL of neodymium neodecanoate in hexane (0.1 M) and maintain for 300 minutes. Immediately afterwards, add 1.0 g of isoprene and 30 mL of butadiene in hexane (2.0 M). Polymerize at 0 °C for 1.0 hour, then terminate with 1.0 g of 4-dimethylaminobenzophenone. Gel permeation chromatography characterization showed that the polymer had a molecular weight of 15.6 kg / mol and a molecular weight distribution of 1.21. C NMR characterization showed that the cis content was 98.5%. H NMR characterization showed that the initiation-end functionalization efficiency was 93.2% and the termination-end functionalization efficiency was 89.4%.

[0075] Example 16

[0076] To 0.9 mL of amine-functionalized alkylaluminum reagent 4 (0.08 M), 0.2 mL of a hexane solution of diisobutylaluminum chloride (0.05 M) was added. After preheating at 50 °C for 10 minutes, 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) was added, and the mixture was maintained for 360 minutes. Immediately afterwards, 6.8 g of isoprene was added, and polymerization was carried out at 30 °C for 0.5 hours. Then, 5 mL of hydrogen peroxide (30 wt.%) was added, followed by 5 mL of sodium hydroxide aqueous solution (10 wt.%) to terminate the polymerization. The polymer obtained by gel permeation chromatography was 13.3 kg / mol with a molecular weight distribution of 1.20. The cis content was 97.5% as characterized by carbon NMR. The functionalization efficiency at the initiation end was 95.5%, and the functionalization efficiency at the termination end was 86.0% as characterized by proton NMR.

[0077] Example 17

[0078] To 1.3 mL of amine-functionalized alkylaluminum reagent 1 (0.08 M), 0.1 mL of ethylaluminum dichloride in hexane (0.05 M) was added. After preheating at 50 °C for 10 minutes, 0.05 mL of neodymium neodecanoate in hexane (0.1 M) was added. Immediately afterwards, 0.14 g of isoprene and 4 mL of butadiene in hexane (2.0 M) were added. Polymerization was carried out at 50 °C for 2.5 hours, and then terminated by adding 2.5 g of dodecyl isocyanate. The polymer obtained by gel permeation chromatography was 11.7 kg / mol with a molecular weight distribution of 1.13. The cis content was 85.6% as characterized by carbon NMR. The functionalization efficiency at the initiation end was 94.6% and the functionalization efficiency at the termination end was 90.7% as characterized by proton NMR.

[0079] Example 18

[0080] Add 0.05 mL of a hexane solution of dichlorodimethylsilane (0.05 M) to 1.3 mL of amino-functionalized alkylaluminum reagent 2 (0.08 M). After preheating at 50 °C for 10 minutes, add 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) and age for 30 minutes. Immediately afterwards, add 5 mL of a hexane solution of butadiene (2.0 M). After polymerization at 50 °C for 3.5 hours, add 1.5 g of 4,4'-bis(dimethylamino)benzophenone to terminate the polymerization. Gel permeation chromatography characterization showed that the polymer had a molecular weight of 12.4 kg / mol and a molecular weight distribution of 1.19. C NMR characterization showed that the cis content was 88.7%. H NMR characterization showed that the initiation-end functionalization efficiency was 95.2% and the termination-end functionalization efficiency was 90.1%.

[0081] Example 19

[0082] Add 0.025 mL of a hexane solution of silicon tetrachloride (0.05 M) to 0.6 mL of amino-functionalized alkyl aluminum reagent 3 (0.08 M). After preheating at 50 °C for 10 minutes, add 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) and age for 60 minutes. Immediately afterwards, add 1.0 mL of isoprene. After polymerization at 50 °C for 1.5 hours, add 5 mL of hydrogen peroxide (30 wt.%), followed by 5 mL of sodium hydroxide aqueous solution (10 wt.%) to terminate the polymerization. Gel permeation chromatography characterization showed that the polymer had a molecular weight of 10.8 kg / mol and a molecular weight distribution of 1.07. C NMR characterization showed that the cis content was 84.30%. H NMR characterization showed that the initiation-terminal functionalization efficiency was 93.5% and the termination-terminal functionalization efficiency was 89.5%.

[0083] Example 20

[0084] 0.4 mL of tert-butyl chloride hexane solution (0.05 M) was added to 0.9 mL of amino-functionalized alkyl aluminum reagent 4 (0.08 M). After preheating at 50 °C for 10 minutes, 0.05 mL of neodymium neodecanoate hexane solution (0.1 M) was added, and the mixture was aged for 60 minutes. Immediately afterwards, 1.0 mL of isoprene was added, and polymerization was carried out at 50 °C for 1.5 hours. The polymerization was then terminated by adding 1.0 g of dodecyl isocyanate. Gel permeation chromatography (GPC) showed that the polymer had a molecular weight of 9.6 kg / mol and a molecular weight distribution of 1.16. Carbon NMR showed that the cis content was 82.40%. Hydrogen NMR showed that the initiation-terminal functionalization efficiency was 95.8% and the termination-terminal functionalization efficiency was 88.6%.

[0085] Example 21

[0086] 0.1 mL of ethylaluminum dichloride (0.05 M) was added to 1.3 mL of hexane solution (0.08 M) of amino-functionalized alkylaluminum reagent 5. After preheating at 0 °C for 10 minutes, 0.05 mL of hexane solution of neodymium neodecanoate (0.1 M) was added. After maintaining at 0 °C for 360 minutes, 0.14 g of isoprene and 4 mL of hexane solution of butadiene (2.0 M) were added. Polymerization was carried out at 0 °C for 5 hours, and then 2.5 g of dodecyl isocyanate was added to terminate the polymerization. The polymer obtained by gel permeation chromatography was 12.8 kg / mol with a molecular weight distribution of 1.32. The cis content was 87.2% as characterized by carbon NMR. The functionalization efficiency at the initiation end was 95.4% and the functionalization efficiency at the termination end was 92.3% as characterized by proton NMR.

[0087] Example 22

[0088] 0.05 mL of neodymium neodecanoate in hexane (0.1 M) was added to 1.3 mL of amino-functionalized alkylaluminum reagent 6 (0.08 M). After preheating at 25 °C for 10 minutes, 0.05 mL of dichlorodimethylsilane in hexane (0.05 M) was added. After maintaining at 25 °C for 180 minutes, 5 mL of butadiene in hexane (2.0 M) was added. Polymerization was carried out at 50 °C for 3.5 hours, and then 1.5 g of 4,4'-bis(dimethylamino)benzophenone was added to terminate the polymerization. The polymer obtained by gel permeation chromatography was 11.4 kg / mol with a molecular weight distribution of 1.29. The cis content was 90.6% as characterized by carbon NMR. The functionalization efficiency at the initiation end was 94.2% and the functionalization efficiency at the termination end was 85.4% as characterized by proton NMR.

[0089] Example 23

[0090] 0.025 mL of a hexane solution of silicon tetrachloride (0.05 M) was added to 0.6 mL of amino-functionalized alkyl aluminum reagent 7 (0.08 M). After preheating at 50 °C for 10 minutes, 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) was added, and the aging time was 60 minutes. Immediately afterwards, 1.0 mL of isoprene was added, and polymerization was carried out at 50 °C for 1.5 hours. Then, 5 mL of hydrogen peroxide (30 wt.%) was added, followed by 5 mL of sodium hydroxide aqueous solution (10 wt.%) to terminate the polymerization. The polymer obtained by gel permeation chromatography was 9.7 kg / mol with a molecular weight distribution of 1.34. The cis content was 85.8% as characterized by carbon NMR. The functionalization efficiency at the initiation end was 95.4%, and the functionalization efficiency at the termination end was 83.2% as characterized by proton NMR.

[0091] Example 24

[0092] 0.4 mL of tert-butyl chloride hexane solution (0.05 M) was added to 0.9 mL of amino-functionalized alkyl aluminum reagent 8 (0.08 M). After preheating at 50 °C for 10 minutes, 0.05 mL of neodymium neodecanoate hexane solution (0.1 M) was added, and the mixture was aged for 60 minutes. Immediately afterwards, 1.0 mL of isoprene was added, and polymerization was carried out at 50 °C for 1.5 hours. Then, 1.0 g of dodecyl isocyanate was added to terminate the polymerization. Gel permeation chromatography (GPC) showed that the polymer had a molecular weight of 10.3 kg / mol and a molecular weight distribution of 1.25. Carbon NMR showed that the cis content was 83.5%. Hydrogen NMR showed that the initiation-terminal functionalization efficiency was 94.0% and the termination-terminal functionalization efficiency was 81.3%.

[0093] Example 25

[0094] Add 0.025 mL of a hexane solution of silicon tetrachloride (0.05 M) to 0.6 mL of amino-functionalized alkyl aluminum reagent 3 (0.08 M). After preheating at 50 °C for 10 minutes, add 0.05 mL of a hexane solution of neodymium neodecanoate (0.1 M) and age for 60 minutes. Immediately afterwards, add 1.0 mL of isoprene. After polymerization at 50 °C for 1.5 hours, purge with dry oxygen (2 mL / min, 5 min). Gel permeation chromatography characterization shows that the polymer has a molecular weight of 9.70 kg / mol, a molecular weight distribution of 1.36, and a cis content of 86.5% as indicated by C NMR. H NMR characterization shows that the initiation-terminal functionalization efficiency is 95.2% and the termination-terminal functionalization efficiency is 85.2%.

Claims

1. A method for polymerizing diterminated conjugated dienes, characterized in that, The method includes: contacting a conjugated diene with a functionalized rare earth catalyst composition in a non-polar solvent, polymerizing for a certain time, and then adding a capping agent to terminate the reaction. The functionalized rare earth catalyst composition comprises a rare earth metal compound, a functionalized alkyl aluminum and a chlorine source in a molar ratio of 1:(10-30):(0-5.0); The rare earth metal element in the rare earth metal compound is neodymium, and the rare earth metal compound is selected from neodymium neodecanoate, neodymium naphthenate, and neodymium isopropoxy. The chlorine source is selected from dichlorodimethylsilane, silicon tetrachloride, tert-butyl chloride, diisobutylaluminum chloride, diethylaluminum chloride, ethylaluminum dichloride, and ethyl sesquichloride. The functionalized alkylaluminum compound has the structure AlR1(R2)2, wherein R1 is selected from one of the following I-XII structural formulas, where R´ is an alkyl group selected from n-butyl, sec-butyl, and tert-butyl, x takes a value of 1-20, m takes a value of 5-20, and n takes a value of 5-20; R2 is selected from one of ethyl, isobutyl, n-butyl, and octyl. ； The method for preparing the functionalized alkyl aluminum compound, When R1 in AlR1(R2)2 is of structural formula I-VI, the preparation method of the functionalized alkylaluminum compound includes the following steps: (1) Dissolve 1-(4-dimethylaminophenyl)-1'-phenylethylene or bis1,1'-(4-dimethylaminophenyl)ethylene in a nonpolar solvent, add alkyl lithium to the resulting solution, and react at 0-50 degrees Celsius for 10-120 minutes; (2) Add the diene monomer to the solution obtained in step (1) and react at 0-50 degrees Celsius for 10-120 minutes; (3) The solution obtained in step (2) is mixed with the alkyl aluminum chloride compound and reacted at 0-50 degrees Celsius for 0-30 minutes to obtain the functionalized alkyl aluminum compound; When R1 in AlR1(R2)2 is of structural formula VII-IX, the preparation method of the functionalized alkylaluminum compound includes the following steps: (1) Dissolve 4-dimethylaminostyrene and diene monomers in a nonpolar solvent, and then add alkyllithium to the resulting solution and react at 0-50 degrees Celsius for 60-240 minutes. (2) The solution obtained in step (1) is mixed with the alkyl aluminum chloride compound and reacted at 0-50 degrees Celsius for 0-30 minutes to obtain the functionalized alkyl aluminum compound; When R1 in AlR1(R2)2 is of structural formula X-XII, the preparation method of the functionalized alkylaluminum compound includes the following steps: (1) Dissolve hexamethyleneimine in a nonpolar solvent, add alkyllithium to the resulting solution, and react at 0-50 degrees Celsius for 10-120 minutes; (2) Add the diene monomer to the solution obtained in step (1) and react at 0-50 degrees Celsius for 10-120 minutes; (3) The solution obtained in step (2) is mixed with the alkyl aluminum chloride compound and reacted at 0-50 degrees Celsius for 0-30 minutes to obtain the functionalized alkyl aluminum compound.

2. The method according to claim 1, characterized in that, In AlR1(R2)2, when R1 is of structural formula I-VI, the concentration of the solute (1-(4-dimethylaminophenyl)-1'-phenylethylene or bis(1,1'-(4-dimethylaminophenyl)ethylene) is 5-30 g / L, the nonpolar solvent is selected from n-hexane, hexane, toluene, and benzene, the alkyl lithium is selected from n-butyllithium, sec-butyllithium, and tert-butyllithium, and the molar ratio of 1-(4-dimethylaminophenyl)-1'-phenylethylene or bis(1,1'-(4-dimethylaminophenyl)ethylene)ethylene to alkyl lithium is 1-20:1; the diene monomer is selected from one or two of butadiene and isoprene, and the molar ratio of the diene monomer to alkyl lithium is 10-40:1; the alkyl aluminum chloride compound is selected from diethylaluminum chloride, diisobutylaluminum chloride, sesquialuminum, and dioctylaluminum chloride; based on the chlorine content, the molar ratio of the alkyl aluminum chloride compound to alkyl lithium is 1.00-1.20:1; In AlR1(R2)2, when R1 is structural formula VII–IX, the molar ratio of 4-dimethylaminostyrene to diene monomer is 1:5-20, the concentration of solute 4-dimethylaminostyrene and diene monomer is 5-30 g / L, the nonpolar solvent is selected from n-hexane, hexane, toluene, and benzene, the alkyl lithium is selected from n-butyllithium, sec-butyllithium, and tert-butyllithium, the molar ratio of 4-dimethylaminostyrene to alkyl lithium is 1-20:1, the diene monomer is selected from one or two of butadiene and isoprene, the molar ratio of diene monomer to alkyl lithium is 10-40:1, the alkyl aluminum chloride compound is selected from diethylaluminum chloride, diisobutylaluminum chloride, sesquialuminum, and dioctylaluminum chloride; based on the chlorine content, the molar ratio of the added alkyl aluminum chloride compound to alkyl lithium is 1.00-1.20:1; In AlR1(R2)2, when R1 is of structural formula X-XII, the concentration of the solute hexamethyleneimine is 5-30 g / L, the nonpolar solvent is selected from n-hexane, hexane, toluene, and benzene, the molar ratio of hexamethyleneimine to alkyl lithium is 1-1.05:1, the alkyl lithium is selected from n-butyl lithium, sec-butyl lithium, and tert-butyl lithium; the diene monomer is selected from one or two of butadiene and isoprene, the molar ratio of diene monomer to alkyl lithium is 1-40:1; the alkyl aluminum chloride compound is selected from diethylaluminum chloride, diisobutylaluminum chloride, sesquialuminum, and dioctylaluminum chloride; based on the chlorine content, the molar ratio of the added alkyl aluminum chloride compound to alkyl lithium is 1.00-1.20:

1.

3. The method according to claim 1, characterized in that, The method for preparing the functionalized rare earth catalyst composition is characterized in that the method includes: under the protection of an inert gas, contacting the three components of rare earth compound, functionalized alkyl aluminum compound and chlorine source in a non-polar solvent, wherein the contact sequence is one of the following: (1) contacting the functionalized alkyl aluminum compound with the chlorine source and then with the rare earth compound; (2) contacting the chlorine source, functionalized alkyl aluminum compound and rare earth compound in sequence; (3) contacting the rare earth compound, functionalized alkyl aluminum compound and chlorine source in sequence; wherein the concentration of rare earth element in the functionalized rare earth catalyst composition is 5-30 mmol / L, and the contact conditions include: temperature of 0-50 degrees Celsius and time of 0-360 minutes.

4. The method according to claim 1, characterized in that, The conjugated diene is selected from one or two of butadiene and isoprene; the molar ratio of the conjugated diene to the functionalized rare earth catalyst composition based on rare earth metal elements is 1000–20000:1; the conditions for the polymerization reaction include: a temperature of 0 to 60 degrees Celsius and a time of 1 to 5 hours.

5. The method according to claim 1, characterized in that, The capping agent is selected from one of the following: benzophenone derivatives, isocyanate derivatives, and oxygen-containing compounds.

6. The method according to claim 5, characterized in that, The benzophenone derivatives include one or more of benzophenone, 4-(dimethylamino)benzophenone, 4-(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, and 4,4'-bis(diethylamino)benzophenone. The isocyanate derivatives include one or more of cyclohexyl isocyanate, octadecyl isocyanate, p-toluene isocyanate, tert-butyl isocyanate, and dodecyl isocyanate; The oxygen-containing compound includes one or more of hydrogen peroxide and oxygen.

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