Preparation method of ternary copolymerization of norbornene, long-chain olefin and methyl acrylate using single titanocene catalyst

Abstract

The present invention belongs to the technical field of cycloolefin polymer synthesis, and specifically relates to a method for preparing a terpolymer of norbornene, long-chain olefin, and methyl acrylate using a single titanocene catalyst. In a catalytic system in which a single titanocene catalyst-cocatalyst is present, norbornene forms a copolymer with methyl acrylate and a long-chain monomer via non-ring-opening addition. The single titanocene catalyst has the structural formula shown in Formula I, wherein R1 is hydrogen, or C1~C 10 A straight chain, branched or isomerized alkyl group, R2 is hydrogen, or C1~C 10 A linear, branched, or isomerized alkyl group; or, R1 is a methyl group or a phenyl group, and R2 is a methyl group or a phenyl group. The present invention utilizes a mono-titanium cyclopentadiene catalyst to catalyze the terpolymerization of norbornene, a long-chain olefin, and methyl acrylate, providing a reference for the catalytic synthesis of cycloolefin polymers. #imgabs0# Formula I

Description

Technical Field

[0001] The invention belongs to the technical field of cycloolefin polymer synthesis, and particularly relates to a method for preparing a terpolymer of norbornene, long-chain olefin and methyl acrylate using a mono-titaniumocene catalyst. Background Art

[0002] Cyclic olefin copolymers obtained by polymerization of norbornene as a monomer have important application value. They have excellent properties such as high refractive index, high glass transition temperature, low density and high heat resistance, and are often used in optics, electronics, pharmaceutical packaging and other fields.

[0003] However, this type of polymer still has disadvantages such as poor solubility, poor bonding performance of substrate materials and difficulty in molding and processing. Therefore, polar monomers such as long-chain olefins and alkyl acrylates can be introduced to chemically modify the cycloolefin polymer, change the rigid structure of the polymer and make it easier to process and shape.

[0004] Metallocene catalysts are a type of catalyst with a sandwich structure. Their main characteristics are: (1) they have a single active site, which helps to obtain polymers with narrow and uniform distribution; (2) they have high catalytic activity, with a catalytic rate close to that of biological enzymes; and (3) the structure of the metallocene catalyst can be customized according to the substrate type to obtain polymers with target molecular weight and stereoregularity. Metallocene catalysts can be used to catalyze the introduction of functional monomers into cycloolefins through non-ring-opening addition polymerization, thereby obtaining cycloolefin polymers with high added value. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing a terpolymer of norbornene, long-chain olefin and methyl acrylate using a mono-titaniumocene catalyst.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for preparing a terpolymer of norbornene, long-chain olefins and methyl acrylate in the presence of a monotitalocene catalyst comprises the following preparation steps: deoxygenating and dehydrating a reactor and introducing nitrogen as a protective gas, with the total monomer concentration being 20 wt%; placing norbornene, methyl acrylate, a co-catalyst and an o-xylene solution in a reactor, simultaneously dropwise adding a certain amount of an o-xylene solution containing the monotitalocene catalyst and an o-xylene solution containing a long-chain olefin, reacting at 20-70°C for about 0.3-0.5 h, maintaining the temperature for 1-6 h, and then adding a 5% by mass methanolic hydrochloric acid solution to terminate the reaction, filtering the product, and vacuum drying the product at 30-40°C.

[0008] The monotitanocenes catalyst preferably has the general structural formula shown in Formula I:

[0009] Formula I,

[0010] Wherein, R1 is hydrogen, or C1~C 10 A straight chain, branched or isomerized alkyl group, R2 is hydrogen, or C1~C 10 a linear, branched or isomerized alkyl group; or, R1 is a methyl group or a phenyl group, and R2 is a methyl group or a phenyl group.

[0011] The monotitanium catalyst more preferably has a structural formula represented by any one of Formulas II to IV.

[0012] Formula II, Formula III, Formula IV.

[0013] The preparation method of the above-mentioned monotitalocene catalyst includes the following preparation steps.

[0014] (1) Preparation of the bridging ligand: Under nitrogen protection, dissolve 1 part of component A (Formula V) and 1 part of component B (Formula VI) in tetrahydrofuran solution, use n-butyl lithium as a catalyst, react at -60°C to 0°C for 12 to 20 hours, and cool and filter the product to obtain the ligand;

[0015] Component A: Formula V, component B Formula VI,

[0016] Wherein, R1 is hydrogen, or C1~C 10 A straight chain, branched or isomerized alkyl group, R2 is hydrogen, or C1~C 10 A straight chain, branched or isomerized alkyl group; or, R1 is a methyl group or a phenyl group, and R2 is a methyl group or a phenyl group;

[0017] (2) The above ligand is reacted with titanium tetrachloride to obtain a monotitalocene catalyst. The specific preparation method is as follows: in a nitrogen environment, one part of the ligand is dissolved in petroleum ether, and one part of titanium tetrachloride dissolved in petroleum ether is slowly added dropwise. The reaction is carried out at -60°C to -40°C for 2-6 hours. The reaction solution is filtered under reduced pressure, and the product is dissolved in toluene for recrystallization and vacuum dried to obtain a monotitalocene catalyst.

[0018] The long-chain olefin refers to an α-olefin having 6 to 24 carbon atoms, preferably 1-hexene, 1-octene, 1-decene, dodecene, tetradecene, or octadecene.

[0019] The terpolymer of norbornene, long-chain olefin and methyl acrylate refers to a copolymer having the formula VII:

[0020] VII,

[0021] Wherein x, y, z and n are integers.

[0022] The preparation of the terpolymer of norbornene, long-chain olefin and methyl acrylate is to react at 20-70° C. for 1-6 hours, more preferably at 40-60° C. for 4-6 hours.

[0023] The molar ratio of the monomers norbornene:long chain olefin:methyl acrylate is (2-1):1:1-0.5; more preferably the molar ratio is 1:1:0.5.

[0024] The amount of the monotitalocene catalyst added in the polymerization reaction is 0.02-0.3% of the total molar amount of the monomers; more preferably 0.04-0.1%.

[0025] The mono-titanium ocene catalyst and the co-catalyst together constitute a catalytic system; the co-catalyst is: methylaluminoxane, ethylaluminoxane, triisobutylaluminum B(C6F5)3, [PhMe2NH][B(C6F5)4] and [Ph3C][B(C6F5)4], one or more of which are used in combination; the molar ratio of the titanocene catalyst to the co-catalyst is preferably: the molar ratio of aluminum in the organoaluminum compound to the titanocene compound is (1-300):1; the molar ratio of boron in the boride to the titanocene compound is 10:1.

[0026] The monotitanium catalyst provided by the present invention has high catalytic activity and can catalyze non-ring-opening polymerization to obtain cycloolefin copolymers. In addition, the introduction of functional groups makes the copolymers more widely applicable.

[0027] The monotitanium catalyst provided by the present invention has better catalytic activity than other catalysts, and improves the controllability of cycloolefin polymerization through steric hindrance effect and electronic effect. Implementation Method

[0028] The present invention will be described in detail below through specific embodiments and examples, and the features and advantages of the present invention will be fully and clearly presented. It should be understood that the described specific embodiments and examples are only a part of the present invention listed and are only used to explain and illustrate, rather than to limit the present invention.

[0029] The cyclic olefin copolymers having the structure of Formula VII in the following examples were prepared by the following method: the reactor was deoxygenated and dehydrated, and nitrogen was introduced to maintain a total monomer concentration of 20 wt%. Norbornene, methyl acrylate, a cocatalyst, and an o-xylene solution were placed in a reactor. A certain amount of an o-xylene solution containing a monotitanocenes catalyst and an o-xylene solution containing a long-chain olefin were simultaneously added dropwise. The reaction was carried out at 40-60°C for approximately 0.3-0.5 h. After incubation for 4 h, a 5% methanolic hydrochloric acid solution was added to terminate the reaction. The product was filtered and dried under vacuum at 30-40°C.

[0030] Example 1

[0031] The synthesis of the monotitanocenes catalyst of structural formula II in this embodiment is as follows:

[0032] (1) Preparation of mono-titanium octyl bridged ligand V (R1 and R2 are methyl): Under nitrogen, 1 mmol of 7-bromoquinoline and 1 mmol of cyclopentadienyldimethylsilyl chloride were dissolved in 20 mL of tetrahydrofuran solution. 5 mL of tetrahydrofuran solution containing 1 mmol of n-butyl lithium was slowly added dropwise over 0.5 hours. The reaction was carried out at -60°C for 12 hours. The product was filtered under reduced pressure and washed with ether to obtain a yellow product with a yield of 67%.

[0033] (2) Under nitrogen, 0.5 mmol of the ligand from step (1) was dissolved in 10 mL of petroleum ether. 10 mL of a petroleum ether solution containing 0.1 mmol of titanium tetrachloride was slowly added dropwise and the mixture was reacted at -60 °C for 3 hours. The reaction solution was filtered under reduced pressure, and the product was dissolved in toluene and recrystallized. The product was a reddish-brown powder with a yield of 43%. The product structure is shown in Formula II. Elemental analysis: Found (calculated), C%, 52.39 (52.06); H%, 4.17 (4.37); N%, 3.90 (3.79).

[0034] Example 2

[0035] The synthesis of the monotitanocenes catalyst of the structural formula III in this embodiment is as follows:

[0036] (1) Preparation of mono-titanium octyl bridged ligand V (R1 is methyl, R2 is phenyl): Under nitrogen protection, 1 mmol of 7-bromoquinoline and 1 mmol of 1-(chloromethylphenylsilyl)-cyclopentadiene-(1,3) were dissolved in 20 mL of tetrahydrofuran solution. 5 mL of tetrahydrofuran solution containing 1 mmol of n-butyl lithium was slowly added dropwise over 0.5 hours. The reaction was carried out at -60°C for 15 hours. The product was filtered under reduced pressure and washed with ether to obtain a yellow product with a yield of 53%.

[0037] (2) Under nitrogen, 0.5 mmol of the ligand from step (1) was dissolved in 10 mL of petroleum ether. 10 mL of a petroleum ether solution containing 0.1 mmol of titanium tetrachloride was slowly added dropwise and the mixture was reacted at -60 °C for 3 hours. The reaction solution was filtered under reduced pressure, and the product was dissolved in toluene and recrystallized. The product was a reddish-brown powder with a yield of 39%. The structural formula of the product is shown in Formula III. Elemental analysis: Found (calculated), C%, 58.23 (58.49); H%, 4.19 (4.21); N%, 3.46 (3.25).

[0038] Example 3

[0039] The synthesis of the monotitanocenes catalyst of the structural formula IV in this embodiment is as follows:

[0040] (1) Preparation of mono-titanium bridging ligand V (R1 and R2 are phenyl): Under nitrogen protection, 1 mmol of 7-bromoquinoline and 1 mmol of cyclopentadienyldiphenylsilyl chloride were dissolved in 20 mL of tetrahydrofuran solution. 5 mL of tetrahydrofuran solution containing 1 mmol of n-butyl lithium was slowly added dropwise over 0.5 hours. The reaction was carried out at -60°C for 15 hours. The product was filtered under reduced pressure and washed with ether to obtain a yellow product with a yield of 69%.

[0041] (2) Under nitrogen, 0.5 mmol of the ligand from step (1) was dissolved in 10 mL of petroleum ether. 10 mL of a petroleum ether solution containing 0.1 mmol of titanium tetrachloride was slowly added dropwise. The mixture was reacted at -60 °C for 3 hours. The reaction solution was filtered under reduced pressure, and the product was dissolved in toluene and recrystallized. The product was a reddish-brown powder with a yield of 47%. The structural formula of the product is shown in Formula IV. Elemental analysis: Found (calculated), C%, 64.51 (64.30); H%, 3.79 (4.09); N%, 2.90 (2.84).

[0042] Example 4

[0043] Preparation of norbornene-1-hexene-methyl acrylate terpolymer: After deoxygenating and dehydrating the reactor and purging it with nitrogen, 95 g of norbornene, 43 g of methyl acrylate, 46 g of methylaluminoxane, and 900 mL of o-xylene solution were placed in the reactor. Simultaneously, 1 g of the monotitanocenes catalyst obtained in Example 1 in 100 mL of o-xylene solution and 85 g of 1-hexene in 115 mL of o-xylene solution were added dropwise. The reaction was allowed to proceed at 50°C for approximately 0.3 to 0.5 h. After incubation for 4 h, the reaction was terminated by adding 5% methanolic hydrochloric acid solution. The product was filtered and vacuum dried at 30 to 40°C. Table 1 records the relevant polymerization data for this example.

[0044] Example 5

[0045] Preparation of norbornene-1-octene-methyl acrylate terpolymer: The reactor was deoxygenated and dehydrated, and nitrogen was introduced. 95 g of norbornene, 43 g of methyl acrylate, 60 g of methylaluminoxane, and 900 mL of o-xylene solution were placed in a reactor. Simultaneously, 100 mL of o-xylene solution containing 0.8 g of the monotitanocenes catalyst obtained in Example 2 and 250 mL of o-xylene solution containing 112 g of 1-octene were added dropwise. The reaction was allowed to proceed at 50°C for approximately 0.3-0.5 h. After incubation for 4 h, the reaction was terminated by the addition of 5% methanolic hydrochloric acid solution. The product was filtered and dried under vacuum at 30-40°C. Table 1 records the relevant polymerization data for this example.

[0046] Example 6

[0047] Preparation of a norbornene-1-decene-methyl acrylate terpolymer: After deoxygenating and dehydrating the reactor and purging it with nitrogen, 95 g of norbornene, 43 g of methyl acrylate, 60 g of methylaluminoxane, and 900 mL of an o-xylene solution were placed in a reactor. Simultaneously, a 100 mL o-xylene solution containing 1.2 g of the monotitanocenes catalyst obtained in Example 2 and a 390 mL o-xylene solution containing 140 g of 1-decene were added dropwise. The reaction was allowed to proceed at 50°C for approximately 0.3 to 0.5 h. After incubation for 4 h, the reaction was terminated by the addition of a 5% methanolic hydrochloric acid solution. The product was filtered and vacuum dried at 30 to 40°C. Table 1 records the relevant polymerization data for this example.

[0048] Example 7

[0049] Preparation of Norbornene-Dodecene-Methyl Acrylate Terpolymer: The reactor was deoxygenated and dehydrated, and nitrogen was introduced. 95 g of norbornene, 43 g of methyl acrylate, 60 g of methylaluminoxane, and 1000 mL of o-xylene solution were placed in a reactor. Simultaneously, 100 mL of o-xylene solution containing 1.2 g of the monotitanocenes catalyst obtained in Example 3 and 530 mL of o-xylene solution containing 168 g of dodecene were added dropwise. The reaction was allowed to proceed at 60°C for approximately 0.3-0.5 h. After incubation for 4 h, the reaction was terminated by the addition of 5% methanolic hydrochloric acid solution. The product was filtered and dried under vacuum at 30-40°C. Table 1 records the relevant polymerization data for this example.

[0050] Example 8

[0051] Preparation of Norbornene-Tetradecene-Methyl Acrylate Terpolymer: The reactor was deoxygenated and dehydrated, and nitrogen was introduced. 95 g of norbornene, 43 g of methyl acrylate, 80 g of methylaluminoxane, and 1000 mL of o-xylene solution were placed in a reactor. Simultaneously, 100 mL of o-xylene solution containing 1.2 g of the monotitanocenes catalyst obtained in Example 3 and 670 mL of o-xylene solution containing 196 g of tetradecene were added dropwise. The reaction was allowed to proceed at 60°C for approximately 0.3-0.5 h. After incubation for 4 h, the reaction was terminated by the addition of 5% methanolic hydrochloric acid solution. The product was filtered and vacuum dried at 30-40°C. Table 1 records the relevant polymerization data for this example.

[0052] Example 9

[0053] Preparation of Norbornene-Octadecene-Methyl Acrylate Terpolymer: The reactor was deoxygenated and dehydrated, and nitrogen was introduced. 95 g of norbornene, 43 g of methyl acrylate, 80 g of methylaluminoxane, and 1000 mL of o-xylene solution were placed in a reactor. Simultaneously, 100 mL of o-xylene solution containing 1.5 g of the monotitanocenes catalyst obtained in Example 3 and 815 mL of o-xylene solution containing 225 g of octadecene were added dropwise. The reaction was allowed to proceed at 60°C for approximately 0.3 to 0.5 h. After incubation for 4 h, the reaction was terminated by the addition of 5% methanolic hydrochloric acid solution. The product was filtered and vacuum dried at 30 to 40°C. Table 1 records the relevant polymerization data for this example.

[0054] Table 1 Polymerization data of Examples 4 to 9

[0055]

[0056] Note: The molecular weight and molecular weight distribution of polymers were measured by GPC, with polystyrene as the standard.

[0057] The norbornene-long-chain olefin-methyl acrylate terpolymer obtained by using the monotitanium octane catalyst provided by the present invention has a relatively high molecular weight and a narrow molecular weight distribution.

Claims

1. A method for ternary copolymerization of norbornene, long-chain olefin and methyl acrylate in the presence of a single titanocene catalyst, characterized in that: The method comprises the following preparation steps: The reactor was deoxygenated and dehydrated, and nitrogen was introduced for protection. The total monomer concentration was 20 wt%; Place norbornene, methyl acrylate, co-catalyst and o-xylene solution in a reaction kettle, and simultaneously add a certain amount of o-xylene solution containing a monotitanocenes catalyst and an o-xylene solution containing a long-chain olefin dropwise. The reaction is carried out at 20-70°C for 0.3-0.5 hours. After keeping the temperature for 1-6 hours, add 5% methanolic hydrochloric acid solution to terminate the reaction, filter, and dry the product in vacuum at 30-40°C. The monotitanocenes catalyst has the structural formula shown in Formula I: Formula I, wherein R1 is a C1-C10 linear, branched or isomerized alkyl group, and R2 is a C1-C10 linear, branched or isomerized alkyl group; or, R1 is a phenyl group, and R2 is a phenyl group.

2. The method according to claim 1, characterized in that The mono-titanium ocene catalyst is used in combination with one or more organoaluminum compounds or organoboron compounds, and the co-catalyst components and ratios are as follows: the molar ratio of aluminum in the organoaluminum compound to the mono-titanium ocene catalyst is (1-300):1; the molar ratio of boron in the organoboron compound to the mono-titanium ocene catalyst is 10:1; The organic aluminum compound includes one or more of methylaluminoxane, ethylaluminoxane and triisobutylaluminum, and the organic boron compound includes one or more of B(C6F5)3, [PhMe2NH][B(C6F5)4] and [Ph3C][B(C6F5)4].

3. The method according to claim 1, characterized in that The prepared copolymer has the structural formula shown in Formula VII: Formula VII, wherein x, y, z and n are all integers.

4. The method according to claim 1, wherein The long-chain olefin is an α-olefin having 6 to 24 carbon atoms.

5. The method according to claim 1, characterized in that The molar ratio of the monomers, norbornene:long chain olefin:methyl acrylate, is (2-1):1:1-0.

5.

6. The method according to claim 1, characterized in that The amount of the monotitalocene catalyst added in the polymerization reaction is 0.02%-0.3% of the total molar amount of the monomers.

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