CN116333004A - Preparation of 2, 6-diisopropylthiophenol single metallocene catalyst and application of catalyst in preparation of functionalized polyolefin - Google Patents

Abstract

The present invention reports the preparation of a 2,6-diisopropylthiophenol monometallocene catalyst and its application in the preparation of functionalized polyolefins. The present invention introduces the anionic ligand 2,6-diisopropylthiophenol, which improves the tolerance of the catalyst to heteroatoms in the polymerization process, and can conveniently regulate the three-dimensional structure of the model metal catalyst by changing the structure of the skeleton. Effect and electronic effect, realize different catalytic properties, and prepare polyolefin polymer materials with various structures and properties. The novel thiophenol monometallocene catalyst reported in this invention has the characteristics of simple preparation, high activity, and good homopolymerization and copolymerization performance, and is suitable for the preparation of reactive polyolefin intermediates with external pendant double bond units by copolymerization of non-conjugated dienes body, and prepare a high molecular weight reactive polyolefin intermediate with a wide distribution. The reactive polyolefin intermediate has a high comonomer insertion rate. Through fine adjustment of the polymer structure, a wide range of material properties can be achieved. With effective control, new functionalized polyolefins can be obtained to meet the needs of different applications. Therefore, the 2,6-diisopropylbenzenethiophenol monometallocene catalyst and its technology for preparing functionalized polyolefins reported in this invention are original and innovative, and can enhance my country's participation in the international high-end polyolefin polymer material technology market competition ability.

Description

Preparation of a 2,6-diisopropylthiophenol monometallocene catalyst and its preparation function Applications of Energized Polyolefins

technical field

The invention relates to the preparation of a 2,6-diisopropylthiophenol monometallocene catalyst and its application in the preparation of functionalized polyolefins.

Background technique

Polyolefin materials have the advantages of high cost performance, good mechanical properties, and stable thermal properties. They are widely used in various fields of industrial production and daily life, and have become the largest class of synthetic polymer materials. However, the inherent non-polarity and inertness of polyolefin materials limit the expansion of their application fields. Therefore, synthesizing functionalized polyolefins to improve their surface properties and compatibility with other materials is of great scientific significance and industrial application value (Science Bulletin 2022, 67, 1881-1894). At present, it is expected to be the most cost-effective method to accurately and efficiently synthesize polyolefins with reactive groups through transition metal coordination insertion, and finally functionalize them to prepare functionalized polyolefins (Prog.Polym.Sci.2002, 27,39-85). With the introduction of "reactive polyolefin intermediates", various functionalized polyolefins have been synthesized by copolymerization of olefins and non-conjugated dienes catalyzed by transition metals such as titanium, zirconium, and hafnium (Angew.Chem., Int. Ed. 2020, 59, 14726-14735). In the process of copolymerization, in order to produce active structural units and avoid polymers with cross-linked structures, it is particularly important to design new catalyst structures and select comonomers with extended structures.

The present invention reports the preparation of a 2,6-diisopropylthiophenol monometallocene catalyst and its application in the preparation of functionalized polyolefins. The present invention introduces the anionic ligand 2,6-diisopropylthiophenol, which improves the tolerance of the catalyst to heteroatoms in the polymerization process, and can conveniently regulate the three-dimensional structure of the model metal catalyst by changing the skeleton structure Effect and electronic effect, realize different catalytic properties, and prepare polyolefin polymer materials with various structures and properties. The novel thiophenol monometallocene catalyst reported in this invention has the characteristics of simple preparation, high activity, and good homopolymerization and copolymerization performance, and is suitable for the preparation of reactive polyolefin intermediates with external pendant double bond units by copolymerization of non-conjugated dienes body, and prepare a high molecular weight reactive polyolefin intermediate with a wide distribution. The reactive polyolefin intermediate has a high comonomer insertion rate. Through fine adjustment of the polymer structure, a wide range of material properties can be achieved. With effective control, new functionalized polyolefins can be obtained to meet the needs of different applications. Therefore, the 2,6-diisopropylthiophenol monometallocene catalyst and its technology for preparing functionalized polyolefins reported in this invention are original and innovative, and can enhance my country's participation in the international high-end polyolefin polymer material technology market competition ability.

Contents of the invention

The object of the present invention is to provide a preparation method of a 2,6-diisopropylthiophenol monometallocene catalyst and its application in the preparation of functionalized polyolefins.

The invention provides a 2,6-diisopropylthiophenol monometallocene catalyst shown in formula (I):

Wherein, X is selected from pentamethylcyclopentadienyl (Cp*), cyclopentadienyl (Cp), indenyl (Ind); R is selected from methyl, chlorine.

The 2,6-diisopropylthiophenol monometallocene catalyst reported by the present invention is selected from any of the following complexes:

Ti1: X=Cp*, R=Cl; Ti2: X=Cp, R=Cl; Ti3: X=Ind, R=Cl.

The present invention provides a preparation method of the above-mentioned 2,6-diisopropylthiophenol monometallocene catalyst, comprising the following steps:

Weigh 2,6-diisopropylthiophenol into a Shrek bottle, connect to double-row vacuum, replace with nitrogen three times, dilute with anhydrous solvent; add n-butyllithium at -78°C under nitrogen atmosphere, and stir at room temperature 2h; the above suspension was slowly introduced into an anhydrous solvent solution of XTiCl ₃ , and reacted at room temperature for 12h; after filtration, the filtrate was recrystallized to obtain the desired catalyst.

In the above preparation method, the anhydrous solvent is selected from benzene, toluene and xylene.

The present invention also provides the application of the 2,6-diisopropylthiophenol monometallocene catalyst represented by the above formula (I) in the preparation of functionalized polyolefins.

In the above application, the olefins are ethylene, propylene, styrene, 1-butene, 1-hexene, 1-octene, norbornene, cyclohexene, tetracyclododecene, 1,5-hexene One or more of diene, 1,7-octadiene, and 1,9-decadiene.

The above-mentioned catalyst is also added with a co-catalyst, and the co-catalyst is one of tripentafluorophenylboron, triphenylcarbenium tetrakis (pentafluorophenyl) borate, aluminoxane, alkylaluminum and alkylaluminum chloride or several. The aluminoxane is methylalumoxane, ethylalumoxane or isobutylalumoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum or tri-n-hexylaluminum; The alkylaluminum chloride is diethylaluminum monochloride, diethylaluminum sesquichloride or ethylaluminum dichloride.

In the above polymerization reaction, the polymerization temperature is 0-180° C., the polymerization pressure is 0.1-5 MPa, and the polymerization solvent is one or more of toluene, hexane, and heptane.

The invention provides the preparation of a 2,6-diisopropylthiophenol monometallocene catalyst and the application of the compound in preparing functionalized polyolefins. The novel 2,6-diisopropylthiophenol monometallocene catalyst reported in this invention has the characteristics of simple preparation, high activity, and good homopolymerization and copolymerization performance, and is suitable for the preparation of non-conjugated diene copolymerization with external suspension double Reactive polyolefin intermediates of key units, and then synthesize functionalized polyolefins.

Description of drawings

Fig. 1 is the crystal structure figure of catalyst Ti1;

Fig. 2 is the crystal structure figure of catalyst Ti2;

Fig. 3 is the crystal structure figure of catalyst Ti3;

Fig. 4 is the high-temperature hydrogen spectrogram of the reactive polyolefin intermediate with external pendant double bond unit;

Fig. 5 is a high-temperature hydrogen spectrogram of functionalized polyolefin after functionalization.

Detailed ways

The present invention is further illustrated by examples, but the present invention is not limited thereto. The embodiments of the present invention can enable those skilled in the art to understand the present invention more comprehensively.

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The present invention is described below with specific examples.

Embodiment 1, the preparation of catalyst Ti1

Weigh 2,6-diisopropylthiophenol into a Shrek bottle, connect to double-row vacuum, replace with nitrogen three times, dilute with anhydrous and oxygen-free toluene; add 1.1 equivalent n-butyl Lithium, stirred at room temperature for 2 hours; under nitrogen atmosphere and low temperature conditions of -78°C, slowly introduce the above suspension into a toluene solution of 1 equivalent of Cp*TiCl ₃ metal, and react at room temperature for 12 hours; after filtration, concentrate the filtrate and recrystallize Ti1 was obtained in 95% yield. ¹ H NMR (400MHz, CDCl ₃ ) δ7.56(dd, J=15.2,7.5Hz,1H),7.43(d,J=7.7Hz,2H),3.48(dt,J=13.7,6.8Hz,2H) ,2.62(s,15H),1.40(d,J＝6.8Hz,12H) ^.13 CNMR(101MHz,CDCl ₃ )δ148.70,140.22,133.27,129.69,123.38,32.58,23.41,14.13.Anal.Calcd for C ₂₂ H ₃₂ Cl ₂ STi: C, 59.75; H, 7.63. Found: C, 59.80; H, 7.65.

Embodiment 2, the preparation of catalyst Ti2

In the same manner as in Example 1, CpTiCl ₃ was used instead of Cp*TiCl ₃ to obtain Ti2 with a yield of 90%. ¹ H NMR (400MHz, CDCl ₃ ) δ7.41(d, J=7.7Hz, 1H), 7.27(s, 1H), 7.25(s, 1H), 6.94(s, 5H), 3.16–3.10(m, 2H), 1.13 (d, J=6.8Hz, 12H). ¹³ C NMR (101MHz, CDCl ₃ ) δ148.29, 140.69, 130.89, 123.86, 120.18, 32.89, 23.55. Anal. Calcd for C ₁₇ H ₂₂ Cl ₂ STi: C, 55.12; H, 6.42. Found: C, 55.15; H, 6.40.

Embodiment 3, the preparation of catalyst Ti3

In the same manner as in Example 1, IndTiCl ₃ was used instead of Cp*TiCl ₃ to obtain Ti3 with a yield of 96%. . ¹ H NMR (400MHz, CDCl ₃ ) δ7.84 (dd, J = 6.5, 3.1 Hz, 2H), 7.43 (dd, J = 6.6, 3.1 Hz, 2H), 7.32–7.29 (m, 3H), 7.14 ( d, J=7.7Hz, 2H), 6.96(t, J=3.4Hz, 1H), 2.95(dt, J=13.6, 6.8Hz, 2H), 1.06(d, J=6.8Hz, 12H). ¹³ C NMR (101MHz, CDCl ₃ ) δ148.17, 140.99, 130.52, 129.49, 128.71, 126.66, 123.61, 120.66, 113.36, 32.55, 23.41. Anal. Calcd for C ₂₁ H ₂₄ Cl ₂ STi: C, 59.74; H, 6.15. Found : C, 59.78; H, 6.20.

Embodiment 4, Ti1 catalytic ethylene polymerization

Dry the 350ml polymerization bottle equipped with a magnetic stirrer at 120°C for more than 6 hours, draw it into the glove box while it is hot, add an appropriate amount of Ti1, and then add d-MAO/Ph ₃ CB[C ₆ F ₅ ] ₄ to make Al/Ti = 50, B/Ti=1.2. It was then evacuated and replaced with ethylene three times. Inject 50ml of toluene with a syringe, keep 5 atm of ethylene pressure at 80°C, and vigorously stir the reaction for 2min. Neutralize the reaction solution with ethanol solution acidified with 5% hydrochloric acid to obtain a polymer precipitate, wash with ethanol several times with water, dry in vacuum until constant weight, and weigh. Polymerization activity: 0.5×10 ⁶ g·mol ^-1 (Ti)·h ^-1 .

Embodiment 5, Ti2 catalytic ethylene polymerization

Dry the 350ml polymerization bottle equipped with a magnetic stirrer at 120°C for more than 6 hours, draw it into the glove box while it is hot, add an appropriate amount of Ti2, and then add d-MAO/Ph ₃ CB[C ₆ F ₅ ] ₄ to make Al/Ti = 50, B/Ti=1.2. It was then evacuated and replaced with ethylene three times. Inject 50ml of toluene with a syringe, keep 5 atm of ethylene pressure at 80°C, and vigorously stir the reaction for 2min. Neutralize the reaction solution with ethanol solution acidified with 5% hydrochloric acid to obtain a polymer precipitate, wash with ethanol several times with water, dry in vacuum until constant weight, and weigh. Polymerization activity: 1.2×10 ⁶ g·mol ^-1 (Ti)·h ^-1 .

Embodiment 6, Ti3 catalytic ethylene polymerization

Dry the 350ml polymerization bottle equipped with a magnetic stirrer at 120°C for more than 6 hours, draw it into the glove box while it is hot, add an appropriate amount of Ti3, and then add d-MAO/Ph ₃ CB[C ₆ F ₅ ] ₄ to make Al/Ti = 50, B/Ti=1.2. It was then evacuated and replaced with ethylene three times. Inject 50ml of toluene with a syringe, keep 5 atm of ethylene pressure at 80°C, and vigorously stir the reaction for 2min. Neutralize the reaction solution with ethanol solution acidified with 5% hydrochloric acid to obtain a polymer precipitate, wash with ethanol several times with water, dry in vacuum until constant weight, and weigh. Polymerization activity: 3.8×10 ⁶ g·mol ^-1 (Ti)·h ^-1 .

Embodiment 7, Ti1 catalyzed ethylene and 1,7-octadiene copolymerization

Dry the 350ml polymerization bottle equipped with a magnetic stirrer at 120°C for more than 6 hours, draw it into the glove box while it is hot, add an appropriate amount of Ti1, and then add d-MAO/Ph ₃ CB[C ₆ F ₅ ] ₄ to make Al/Ti = 50, B/Ti=1.2. It was then evacuated and replaced with ethylene three times. Use a syringe to inject 30ml of toluene and 0.5M 1,7-octadiene. At 80°C, keep 5 atm of ethylene pressure, and vigorously stir the reaction for 10 minutes. The reaction solution was neutralized with 5% hydrochloric acid acidified ethanol solution to obtain a polymer precipitate, which was centrifuged, dried in vacuum until constant weight, and weighed. Polymerization activity: 8.2×10 ⁵ g·mol ^-1 (Ti)·h ^-1 , monomer insertion rate 13.6%.

Embodiment 8, Ti2 catalytic ethylene and 1,7-octadiene copolymerization

Dry the 350ml polymerization bottle equipped with a magnetic stirrer at 120°C for more than 6 hours, draw it into the glove box while it is hot, add an appropriate amount of Ti2, and then add d-MAO/Ph ₃ CB[C ₆ F ₅ ] ₄ to make Al/Ti = 50, B/Ti=1.2. It was then evacuated and replaced with ethylene three times. Use a syringe to inject 30ml of toluene and 0.5M 1,7-octadiene. At 80°C, keep 5 atm of ethylene pressure, and vigorously stir the reaction for 10 minutes. The reaction solution was neutralized with 5% hydrochloric acid acidified ethanol solution to obtain a polymer precipitate, which was centrifuged, dried in vacuum until constant weight, and weighed. Polymerization activity: 5.1×10 ⁵ g·mol ^-1 (Ti)·h ^-1 , monomer insertion rate 15.8%.

Embodiment 9, Ti3 catalyst ethylene and 1,7-octadiene copolymerization

Dry the 350ml polymerization bottle equipped with a magnetic stirrer at 120°C for more than 6 hours, draw it into the glove box while it is hot, add an appropriate amount of Ti3, and then add d-MAO/Ph ₃ CB[C ₆ F ₅ ] ₄ to make Al/Ti = 50, B/Ti=1.2. It was then evacuated and replaced with ethylene three times. Inject 30ml of toluene and 2M 1,7-octadiene with a syringe, keep the ethylene pressure of 5atm at 80°C, and vigorously stir the reaction for 10min. The reaction solution was neutralized with 5% hydrochloric acid acidified ethanol solution to obtain a polymer precipitate, which was centrifuged, dried in vacuum until constant weight, and weighed. Polymerization activity: 6.8×10 ⁵ g·mol ^-1 (Ti)·h ^-1 , monomer insertion rate 50.8%.

Example 10, Preparation of functionalized polyethylene by reaction of mercaptoacetic acid, copolymer of ethylene and 1,7-octadiene

Weigh 100mg of the sample obtained by copolymerization of ethylene and 1,7-octadiene into a 25mL Shrek tube, add 5mL of anisole solvent, place it in an oil bath at 100°C to fully dissolve it for 1 hour, and the solution is transparent and homogeneous. phase liquid; add 10 equivalents of thioglycolic acid reagent of the VHX unit content in the sample to it, add 0.1 equivalent of the thermal initiator 2,2'-azobisisobutyronitrile (AIBN) of the double bond content of the sample, and seal the reaction system ; use liquid nitrogen to freeze the whole system and then pump out the gas, heat and melt the reaction system with a hair dryer and then replenish nitrogen, repeat this operation three times, and after a little degassing, reflux it for 10 hours under the protection of nitrogen, and the whole system is transparent Homogeneous liquid; slowly drop the reaction solution into 50mL of cold methanol to precipitate, then centrifuge at 10,000r/min for 3min to collect the polymer, and dry it in a vacuum oven at 60°C until the polymer reaches a constant weight and The mass was recorded and the degree of functionalization was calculated by ¹ H NMR of the polymer in 1,1,2,2-tetrachloroethane-d ₂ (C ₂ D ₂ Cl ₄ -d ₂ ). The degree of reaction between thioglycolic acid and the double bond is >99%, that is, the degree of functionalization is >99%.

Example 11, Preparation of functionalized polyethylene by reaction of benzylmercaptan with copolymer of ethylene and 1,7-octadiene

Weigh 100mg of the sample obtained by copolymerization of ethylene and 1,7-octadiene into a 25mL Shrek tube, add 5mL of anisole solvent, place it in an oil bath at 100°C to fully dissolve it for 1 hour, and the solution is transparent and homogeneous. Phase liquid; 10 equivalents of benzylthiol reagent of the VHX unit content in the sample was added thereto, and 0.1 equivalent of the thermal initiator 2,2'-azobisisobutyronitrile (AIBN) of the double bond content of the sample was added to block the reaction system; use liquid nitrogen to freeze the whole system and then pump out the gas, heat and melt the reaction system with a hair dryer and then replenish nitrogen, repeat this operation three times, and after a little degassing, reflux it for 10 hours under the protection of nitrogen, and the whole system is transparent The homogeneous liquid; slowly drop the reaction solution into 50mL of cold methanol to precipitate, then centrifuge at 10,000r/min for 3min to collect the polymer, and dry it in a vacuum oven at 60°C until it reaches a constant weight to obtain the polymer The mass was recorded, and the degree of functionalization was calculated by measuring ¹ H NMR of the polymer in 1,1,2,2-tetrachloroethane- _{d 2} (C ₂ D ₂ Cl ₄ -d ₂ ). The degree of reaction between benzylthiol and the double bond is 54%, that is, the degree of functionalization is 54%.

Claims (8)

1. A2, 6-diisopropylthiophenol single metallocene catalyst has a structure shown in a formula (I):

wherein X is selected from pentamethylcyclopentadienyl (Cp), cyclopentadienyl (Cp), indenyl (Ind); r is selected from methyl and chlorine.

2. The process for preparing a 2, 6-diisopropylthiophenol single metallocene catalyst of claim 1, comprising the steps of: weighing 2, 6-diisopropyl thiophenol in a Schlenk bottle, vacuumizing by double rows, replacing with nitrogen for three times, and diluting with an anhydrous solvent; n-butyllithium is added in a nitrogen atmosphere at the temperature of minus 78 ℃ and stirred for 2 hours at room temperature; slowly introducing the suspension into XTiCl ₃ Is an anhydrous solvent solution of (2)Reacting for 12 hours at room temperature; after filtration, the filtrate was recrystallized to give the desired catalyst.

3. The preparation method according to claim 2, characterized in that: the anhydrous solvent is selected from benzene, toluene and xylene.

4. A process for carrying out an olefin polymerization reaction, characterized by: the catalyst for the reaction is the 2, 6-diisopropylthiophenol single metallocene catalyst of claim 1.

5. The method according to claim 4, wherein: the olefin is one or more of ethylene, propylene, styrene, 1-butene, 1-hexene, 1-octene, norbornene, cyclohexene, tetracyclododecene, 1, 5-hexadiene, 1, 7-octadiene and 1, 9-sunflower diene.

6. The method according to claim 4, wherein: the catalyst is also added with a cocatalyst which is one or more of trifluorophenyl boron, triphenylcarbonium tetra (pentafluorophenyl) borate, aluminoxane, alkyl aluminum and alkyl aluminum chloride.

7. The method according to claim 6, wherein: the aluminoxane is methylaluminoxane, ethylaluminoxane or isobutylaluminoxane; the alkyl aluminum is trimethyl aluminum, triethyl aluminum, triisobutyl aluminum or tri-n-hexyl aluminum; the alkyl aluminum chloride is diethyl aluminum chloride, diethyl aluminum sesquichloride or ethyl aluminum dichloride.

8. The method according to claim 4, wherein: the polymerization temperature is 0-180 ℃, the polymerization pressure is 0.1-5MPa, and the polymerization solvent is one or more of toluene, hexane and heptane.

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