阅读说明：本技术 一种低顺式、高乙烯基端羟基聚丁二烯橡胶的制备方法 (Preparation method of low cis-high ethylene-based hydroxyl polybutadiene rubber ) 是由 黎广贞 王平 杨寿盛 郑岩 张海涛 廖伟超 舒畅 谢宝东 刘君 刘敏 张先汉 于 2021-07-16 设计创作，主要内容包括：本发明提供一种低顺式、高乙烯基端羟基聚丁二烯橡胶的制备方法,所述制备方法包括以下步骤：(1)双官能团引发剂的制备：将双官能团共轭烯烃与碱金属烷基化合物反应得到双官能团引发剂；(2)活性聚丁二烯的制备；(3)开环反应终止聚合,(4)水解得到碱性端羟基聚丁二烯胶液；(5)通入二氧化碳进行碱性中和,得到端羟基聚丁二烯,而后加入防老剂,去除溶剂,得到所述低顺式、高乙烯基端羟基聚丁二烯胶液。本发明的制备方法得到的端羟基聚丁二烯橡胶数均分子量在5000-10000g/mol,顺式含量为10-25％,反式含量为40-60％,1,2结构含量为30-45％,1,4-结构含量为60-75％。(The invention provides a preparation method of low cis-high ethylene-terminated hydroxyl polybutadiene rubber, which comprises the following steps: (1) preparing a bifunctional initiator: reacting bifunctional conjugated olefin with an alkali metal alkyl compound to obtain a bifunctional initiator; (2) preparing active polybutadiene; (3) ring-opening reaction to terminate polymerization, (4) hydrolysis to obtain alkaline hydroxyl-terminated polybutadiene glue solution; (5) introducing carbon dioxide to perform alkaline neutralization to obtain hydroxyl-terminated polybutadiene, then adding an anti-aging agent, and removing the solvent to obtain the low cis-form high ethylene-terminated hydroxyl-terminated polybutadiene glue solution. The hydroxyl-terminated polybutadiene rubber obtained by the preparation method has the number average molecular weight of 5000-10000g/mol, the cis content of 10-25%, the trans content of 40-60%, the 1,2 structure content of 30-45% and the 1,4 structure content of 60-75%.)

1. A method for preparing a low-cis, high-ethylene-based hydroxyl polybutadiene rubber, comprising the steps of:

(1) preparing a bifunctional initiator: reacting bifunctional conjugated olefin with an alkali metal alkyl compound to obtain a bifunctional initiator;

(2) preparation of activated polybutadiene: initiating a butadiene monomer to carry out polymerization reaction by using the bifunctional initiator obtained in the step (1) to obtain active polybutadiene;

(3) ring opening reaction terminating polymerization: adding an epoxy compound or a carbonyl compound into the activated polybutadiene obtained in the step (2), reacting, and terminating the polymerization reaction;

(4) hydrolyzing to obtain alkaline hydroxyl-terminated polybutadiene glue solution: adding water into the reaction liquid obtained in the step (3) for hydrolysis to obtain an alkaline hydroxyl-terminated polybutadiene glue solution;

(5) introducing carbon dioxide for alkaline neutralization: and (4) introducing carbon dioxide into the alkaline hydroxyl-terminated polybutadiene glue solution obtained in the step (4) for neutralization to obtain hydroxyl-terminated polybutadiene, then adding an anti-aging agent, and removing the solvent to obtain the low cis-form high ethylene-terminated hydroxyl-terminated polybutadiene glue solution.

2. The method according to claim 1, wherein the bifunctional conjugated olefin of step (1) is divinylbenzene and/or divinylnaphthalene.

3. The production method according to claim 1 or 2, wherein the alkali metal alkyl compound in step (1) is n-butyllithium or sec-butyllithium;

preferably, the reaction in step (1) is carried out under the protection of nitrogen;

preferably, the solvent for the reaction of step (1) is a non-polar solvent; preferably any one or a combination of at least two of cyclohexane, cyclopentane, methylcyclopentane, n-heptane and toluene;

preferably, the temperature of the reaction of step (1) is 45-60 ℃;

preferably, the reaction time in step (1) is 10-30 min.

4. The production method according to any one of claims 1 to 3, wherein the polymerization system of step (2) further comprises a structure-regulating agent;

preferably, the structure regulator is a mixed solution of tetrahydrofuran and N, N-dimethylformamide, a mixed solution of tetrahydrofuran and tetramethylethylenediamine, a mixed solution of tetrahydrofuran and 2, 2-bis (2-tetrahydrofuryl) propane or a mixed solution of 2, 2-bis (2-tetrahydrofuryl) propane and tetrahydrofurfuryl alcohol ethyl ether;

preferably, the mass ratio of the tetrahydrofuran to the N, N-dimethylformamide in the mixed solution of the tetrahydrofuran and the N, N-dimethylformamide is 1:1-2: 1;

preferably, the mass ratio of the tetrahydrofuran to the tetramethylethylenediamine in the mixed solution of the tetrahydrofuran and the tetramethylethylenediamine is 1:1-2: 1.

Preferably, the mass ratio of the tetrahydrofuran to the 2, 2-bis (2-tetrahydrofuryl) propane in the mixed solution of the tetrahydrofuran and the 2, 2-bis (2-tetrahydrofuryl) propane is 1:2-1: 3;

preferably, the mass ratio of the 2, 2-bis (2-tetrahydrofuryl) propane to the tetrahydrofurfuryl alcohol ethyl ether in the mixed solution of the 2, 2-bis (2-tetrahydrofuryl) propane and the tetrahydrofurfuryl alcohol ethyl ether is 1:2-1: 3.

5. The method according to any one of claims 1 to 4, wherein the polymerization reaction in the step (2) is initiated at a temperature of 45 to 50 ℃ and a temperature peak of 95 to 105 ℃;

preferably, the polymerization reaction time of the step (2) is 1 to 2 hours;

preferably, the epoxy compound of step (3) is ethylene oxide and/or propylene oxide;

preferably, the carbonyl compound in step (3) is acetone and/or butanone;

preferably, the molar ratio of the epoxy compound or the carbonyl compound to the bifunctional initiator in step (3) is 1:1.0 to 1.5.

6. The method according to any one of claims 1 to 5, wherein the temperature of the reaction in step (3) is 85 to 95 ℃;

preferably, the epoxy compound or the carbonyl compound in the step (3) is added into the system in a dropwise manner, wherein dropwise addition is performed at 3-5 drops per second;

preferably, the reaction time of the step (3) is 10-20 min.

7. The process according to any one of claims 1 to 6, wherein the water is added in step (4) in an amount of 1.0 to 1.5 times, preferably 1.2 times, the molar amount of the active groups of the bifunctional initiator;

preferably, the hydrolysis time in step (4) is 15-20min, preferably 20 min.

8. The production method according to any one of claims 1 to 7, wherein the carbon dioxide is introduced in step (5) for a period of 20 to 40min, preferably 30 min;

preferably, the antioxidant in the step (5) is a combination of hindered phenol antioxidant and phosphite ester antioxidant;

preferably, the hindered phenol type anti-aging agent is any one or a combination of at least two of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 2- [1- (2-hydroxy-3, 5-di-tert-pentylphenyl) ethyl ] -4, 6-di-tert-pentylphenyl acrylate and 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-tolylmethyl) -4-methylphenol acrylate;

preferably, the phosphite antioxidant is any one of tris (2, 4-di-tert-butylphenyl) phosphite, pentaerythritol diphosphite bis [ (2, 4-di-tert-butylphenyl) propionate ] and tris (tridecyl) phosphite, or a combination of at least two of the foregoing;

preferably, the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant in the step (5) is 1: 1;

preferably, the antioxidant of step (5) is added in an amount of 1.0 to 1.5phr, preferably 1.3 phr.

9. A low cis, high ethylene-terminated hydroxyl polybutadiene rubber prepared by the preparation process according to any one of claims 1-8.

10. The low cis, high ethylene-based hydroxyl polybutadiene rubber as claimed in claim 9, wherein the hydroxyl-terminated polybutadiene rubber has a number average molecular weight of 5000-10000g/mol, a cis content of 10-25%, a trans content of 40-60%, a 1, 2-structure content of 30-45%, a 1, 4-structure content of 60-75%, a molecular weight distribution of 1.0-1.2, and a functionality of 1.8-2.1.

Technical Field

The invention belongs to the technical field of polymer synthesis, and relates to a preparation method of low cis-form and high ethylene-based hydroxyl polybutadiene rubber.

Background

Hydroxyl-terminated polybutadiene can be divided into high trans-hydroxyl-terminated polybutadiene, high cis-hydroxyl-terminated polybutadiene and high ethylene-terminated hydroxyl-terminated polybutadiene in the field of product microcosmic composition. At present, hydroxyl-terminated polybutadiene is widely used in military fields, such as high-energy fuel coating agents in solid rocket propellants, and the like, a free radical process is adopted in industrial production, and mainly comprises trans-1, 4 polymerization (more than 60%), but the molecular weight distribution is wide, the content of 1, 2-polymer in the high-ethylene-terminated hydroxyl-terminated polybutadiene is over 80% developed by Japan Caoda corporation, the process route adopts anionic polymerization, the molecular weight distribution of the product is narrow, the performance is stable, and the hydroxyl-terminated polybutadiene is frequently used in the electronic field, especially in the field of laminating agents of 5G circuit boards.

The low cis rubber is short for low cis polybutadiene rubber, and compared with high cis rubber, the low cis rubber has the advantages of low gel content, good solution chroma, no transition metal, proper rubber particle size and the like. Because the production process has high control requirement, the rubber belongs to a fine product in synthetic rubber products, and the high-end low-order rubber used in China at present mainly depends on import.

CN104448059A discloses epoxidized hydroxyl-terminated polybutadiene liquid rubber with high cis-1, 4 content and a preparation method thereof, wherein the process route is that firstly butadiene rubber is adopted for epoxidation to prepare the epoxidized polybutadiene, and then the ring opening reaction is carried out on an epoxy group to prepare the hydroxyl-terminated polybutadiene, and the control of the hydroxyl-terminated polybutadiene is difficult. CN106749775A discloses that epoxy hydroxyl-terminated polybutadiene is prepared by adopting hydroxyl-terminated polybutadiene for epoxidation reaction, and the preparation process of hydroxyl-terminated polybutadiene base glue is not involved.

Accordingly, it is desirable in the art to develop a process for the preparation of low cis, high ethylene-based hydroxyl polybutadiene rubber.

Disclosure of Invention

In view of the disadvantages of the prior art, the present invention aims to provide a process for producing a low cis, high ethylene-based hydroxyl polybutadiene rubber. The hydroxyl-terminated polybutadiene rubber obtained by the preparation method has the number average molecular weight of 5000-10000g/mol, the cis content of 10-25%, the trans content of 40-60%, the 1,2 structure content of 30-45% and the 1,4 structure content of 60-75%.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a process for preparing a low cis, high ethylene-based hydroxyl polybutadiene rubber, said process comprising the steps of:

(1) preparing a bifunctional initiator: reacting bifunctional conjugated olefin with an alkali metal alkyl compound to obtain a bifunctional initiator;

(2) preparation of activated polybutadiene: initiating a butadiene monomer to carry out polymerization reaction by using the bifunctional initiator obtained in the step (1) to obtain active polybutadiene;

(3) ring opening reaction terminating polymerization: adding an epoxy compound or a carbonyl compound into the activated polybutadiene obtained in the step (2), reacting, and terminating the polymerization reaction;

(4) hydrolyzing to obtain alkaline hydroxyl-terminated polybutadiene glue solution: adding water into the reaction liquid obtained in the step (3) for hydrolysis to obtain an alkaline hydroxyl-terminated polybutadiene glue solution;

(5) introducing carbon dioxide for alkaline neutralization: and (4) introducing carbon dioxide into the alkaline hydroxyl-terminated polybutadiene glue solution obtained in the step (4) for neutralization to obtain hydroxyl-terminated polybutadiene, then adding an anti-aging agent, and removing the solvent to obtain the low cis-form high ethylene-terminated hydroxyl-terminated polybutadiene glue solution.

In the invention, bifunctional initiator is obtained by using bifunctional conjugated olefin to react with alkali metal alkyl compound, and the bifunctional initiator is obtained by controlling conditions and avoiding divinylbenzene from participating in polymerization reaction in a molecular weight chain.

In the present invention, the low cis-form means a cis-form content of 25% or less, the high vinyl-form means a 1, 2-structure content of 30% or more and a 1, 4-structure content of 60% or more in the polybutadiene rubber.

In the present invention, the bifunctional conjugated olefin of step (1) is divinylbenzene and/or divinylnaphthalene.

Preferably, the alkali metal alkyl compound of step (1) is n-butyllithium or sec-butyllithium.

Preferably, the reaction of step (1) is carried out under nitrogen protection.

Preferably, the solvent for the reaction of step (1) is a non-polar solvent; any one or a combination of at least two of cyclohexane, cyclopentane, methylcyclopentane, n-heptane, and toluene is preferred.

Preferably, the temperature of the reaction in step (1) is 45-60 ℃, such as 45 ℃, 50 ℃, 55 ℃ or 60 ℃.

Preferably, the reaction time in step (1) is 10-30min, such as 10min, 15min, 20min, 25min, 30 min.

Preferably, the polymerization reaction system in the step (2) further comprises a structure regulator.

Preferably, the structure regulator is a mixture of tetrahydrofuran and N, N-dimethylformamide, a mixture of tetrahydrofuran and tetramethylethylenediamine, a mixture of tetrahydrofuran and 2, 2-bis (2-tetrahydrofuryl) propane, or a mixture of 2, 2-bis (2-tetrahydrofuryl) propane and tetrahydrofurfuryl alcohol ethyl ether.

Preferably, the mass ratio of tetrahydrofuran to N, N-dimethylformamide in the mixture of tetrahydrofuran and N, N-dimethylformamide is 1:1 to 2:1, such as 1:1, 1.2:1, 1.4:1, 1.5:1, 1.6:1, 1.8:1 or 2: 1.

Preferably, the mass ratio of tetrahydrofuran to tetramethylethylenediamine in the mixture of tetrahydrofuran and tetramethylethylenediamine is 1:1 to 2:1, for example, 1:1, 1.2:1, 1.4:1, 1.5:1, 1.6:1, 1.8:1 or 2: 1.

Preferably, the mass ratio of tetrahydrofuran to 2, 2-bis (2-tetrahydrofuryl) propane in the mixture of tetrahydrofuran and 2, 2-bis (2-tetrahydrofuryl) propane is 1:2 to 1:3, such as 1:2, 1:2.2, 1:2.4, 1:2.5, 1:2.6, 1:2.8, 1: 3.

Preferably, the mass ratio of the 2, 2-bis (2-tetrahydrofuryl) propane to the tetrahydrofurfuryl alcohol ethyl ether in the mixed solution of the 2, 2-bis (2-tetrahydrofuryl) propane and the tetrahydrofurfuryl alcohol ethyl ether is 1:2 to 1:3, such as 1:2, 1:2.2, 1:2.4, 1:2.5, 1:2.6, 1:2.8 and 1: 3.

Preferably, the initiation temperature in the polymerization reaction in the step (2) is 45 to 50 ℃ (e.g., 45 ℃, 46 ℃, 47 ℃, 48 ℃, 49 ℃ or 50 ℃) and the temperature peak is 95 to 105 ℃ (e.g., 95 ℃, 97 ℃, 98 ℃, 99 ℃, 100 ℃, 102 ℃, 104 ℃, etc.).

Preferably, the polymerization reaction of step (2) is carried out for 1 to 2 hours, such as 1 hour, 1.1 hour, 1.3 hours, 1.5 hours, 1.7 hours, 1.9 hours, etc.

Preferably, the epoxy compound of step (3) is ethylene oxide and/or propylene oxide.

Preferably, the carbonyl compound in step (3) is acetone and/or butanone.

Preferably, the molar ratio of the epoxy compound or carbonyl compound to the difunctional initiator in step (3) is 1:1.0 to 1.5, such as 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1: 1.5.

Preferably, the temperature of the reaction in step (3) is 85-95 deg.C, such as 85 deg.C, 86 deg.C, 87 deg.C, 88 deg.C, 89 deg.C, 90 deg.C, 91 deg.C, 92 deg.C, 93 deg.C, 94 deg.C, 95 deg.C, preferably 90 deg.C. And (3) a temperature reduction process, wherein the reaction temperature is that the temperature is preserved according to the temperature, and then an epoxy compound or a carbonyl compound is added for reaction so as to ensure that the epoxy group or the carbonyl is completely stopped.

Preferably, the epoxy compound or the carbonyl compound in the step (3) is added to the system in a dropwise manner, wherein the dropwise addition is performed at 3 to 5 drops per second.

Preferably, the reaction time of the step (3) is 10-20 min. For example 10min, 12min, 14min, 16min, 18min or 20 min.

Preferably, the amount of water added in step (4) is 1.0 to 1.5 times, such as 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, etc., preferably 1.2 times, the molar amount of active groups of the bifunctional initiator.

Preferably, the hydrolysis time in step (4) is 15-20min, such as 15min, 16min, 17min, 18min, 19min, 20min, etc., preferably 20 min.

In the present invention, after the epoxy compound or carbonyl compound in step (3) is terminated, the obtained alkali metal organic alcohol compound (such as lithium polybutadiene alcohol, lithium potassium polybutadiene alcohol, sodium polybutadiene alcohol, etc.) is hydrolyzed by adding water in step (4), and after sufficient reaction time, hydroxyl-terminated polybutadiene and alkali metal hydroxide compound are obtained.

Preferably, the introducing time of the carbon dioxide in the step (5) is 20-40min, such as 20min, 25min, 30min, 35min, 40min, etc., preferably 30 min.

Preferably, the antioxidant in the step (5) is a combination of hindered phenol antioxidant and phosphite antioxidant.

Preferably, the hindered phenol type anti-aging agent is any one or a combination of at least two of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 2- [1- (2-hydroxy-3, 5-di-tert-pentylphenyl) ethyl ] -4, 6-di-tert-pentylphenyl acrylate and 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-tolylmethyl) -4-methylphenol acrylate;

preferably, the phosphite antioxidant is any one of tris (2, 4-di-tert-butylphenyl) phosphite, pentaerythritol diphosphite bis [ (2, 4-di-tert-butylphenyl) propionate ] and tris (tridecyl) phosphite, or a combination of at least two of the foregoing;

preferably, the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant in the step (5) is 1:1.

Preferably, the antioxidant of step (5) is added in an amount of 1.0 to 1.5phr, such as 1.0, 1.1, 1.2, 1.3, 1.4, 1.5phr and the like, preferably 1.3 phr.

Under strong alkaline conditions, the efficiency of an antioxidant system of the hydroxyl-terminated polybutadiene polymer is reduced, and molecular chain crosslinking or chain breakage is easy to occur, so that carbon dioxide and an alkali metal hydroxide compound are introduced in the step (5) for neutralization to obtain the hydroxyl-terminated polybutadiene with good stability.

Preferably, the solvent removal in the step (5) is performed by adopting a wiped film evaporation mode, a kettle type vacuum mode and a falling film evaporation mode, and the solvent removal is preferably performed by adopting a wiped film evaporation mode.

In another aspect, the present invention provides a low cis, high ethylene-based hydroxyl polybutadiene rubber prepared as described above.

In the present invention, the hydroxyl-terminated polybutadiene rubber prepared by the preparation method has a number average molecular weight of 5000-10000g/mol (e.g., 5000g/mol, 6000g/mol, 7000g/mol, 8000g/mol, 9000g/mol or 10000g/mol), a cis content of 10 to 25% (e.g., 10%, 13%, 15%, 18%, 20%, 22% or 25%), a trans content of 40 to 60% (e.g., 40%, 43%, 45%, 48%, 50%, 53%, 55%, 58% or 60%), a 1, 2-structure content of 30 to 45% (e.g., 30%, 33%, 35%, 40%, 43% or 45%), a 1, 4-structure content of 60 to 75% (e.g., 60%, 63%, 65%, 68%, 70%, 73% or 75%), and a molecular weight distribution of 1.0 to 1.2 (e.g., 1.0, 0, 1.2), 1.05, 1.1, 1.15, or 1.2), and a functionality of 1.8 to 2.1 (e.g., 1.8, 1.9, 2.0, or 2.1, etc.).

Compared with the prior art, the invention has the following beneficial effects:

the low cis-high ethylene-terminated hydroxyl polybutadiene rubber is prepared by an anion mode, the number average molecular weight is 10000g/mol of 5000-25%, the cis-content is 10-25%, the trans-content is 40-60%, the 1, 2-structure content is 30-45%, the 1, 4-structure content is 60-75%, the molecular weight is distributed in 1.005-1.2, and the functionality is 1.8-2.1.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

In this example, a low cis, high ethylene-based hydroxyl polybutadiene rubber was prepared by the following preparation method:

a500 mL glass bottle with an opening is placed in a nitrogen sealed box, 30g of 20% n-butyllithium solution and 54g of cyclohexane are weighed firstly and poured into the glass bottle, 0.01g of tetrahydrofuran is added and shaken well, then 12g of divinylbenzene is weighed and dripped into 7% n-butyllithium cyclohexane solution in a dripping mode, the reaction releases heat quickly, the mixture is dripped and shaken fully and is placed in cold water for cooling, a thermometer is arranged in the glass bottle and is inserted into the reaction liquid, and after the scale of the thermometer does not rise any more, the mixture is sealed, cooled and stored for later use.

Replacing a 10L reaction kettle with high-purity nitrogen, adding 4500g cyclohexane/n-hexane mixed solvent, adding 1.35g THF (tetrahydrofuran)/DMF (dimethylformamide) (preparing solution according to the mass ratio of 1: 1), stirring (150r/min), stirring completely, and cooling to 40-45 deg.CFirstly adding 32g of the prepared bi/multifunctional chain extension initiator, uniformly stirring, then adding 200g of butadiene, controlling the temperature peak at 95-105 ℃ until the temperature does not rise for about 3min, then adding 1.5g of ethylene oxide for reaction for 15min, adding 1g of water for hydrolysis reaction for 10min, then introducing 20min of carbon dioxide into the liquid hydroxyl-terminated polybutadiene glue solution, and then adding tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]A combined antioxidant of pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite, the amount of the antioxidant added being 1.3phr, wherein tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]Adding pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite at a ratio of 1:1, vacuumizing and extracting cyclohexane solvent to obtain pure liquid hydroxyl-terminated polybutadiene, GPC-characterized to obtain a number average molecular weight of 6600g/mol and a molecular weight distribution of 1.05, and subjecting the pure liquid hydroxyl-terminated polybutadiene to infrared spectroscopy and tris (2, 4-di-tert-butylphenyl) phosphite¹H NMR and¹³c NMR tests show that the cis-1, 4 structure, trans-1, 4 structure and 1, 2-vinyl content are respectively 12.1%, 57.4% and 30.5%, and the hydroxyl functionality is 2.5.

Example 2

In this example, a low cis, high ethylene-based hydroxyl polybutadiene rubber was prepared by the following preparation method:

the initiator preparation is the same as example 1, adding 4500g cyclohexane/n-hexane mixed solvent into a 10L reaction kettle, adding 1.35g THF (tetrahydrofuran) and TMEDA (tetramethylethylenediamine) preparation solution (prepared according to the mass ratio of 2: 1), starting stirring (150r/min), fully stirring, adding 32g the prepared bi/multifunctional chain extension initiator after the temperature reaches 40-45 ℃, stirring, adding 200g butadiene, controlling the temperature peak at 95-105 ℃ until the temperature does not rise for about 3min, adding 1.5g ethylene oxide for reaction for 15min, adding 1g water for hydrolysis reaction for 10min, introducing carbon dioxide into the liquid hydroxyl-terminated polybutadiene glue solution for 20min, and adding tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]A combined antioxidant of pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite, the amount of the antioxidant added being 1.3phr, wherein tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]Pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite are added in a ratio of 1:1, and then vacuum evacuation is carried outAnd (3) pulling out the cyclohexane solvent to obtain the pure liquid hydroxyl-terminated polybutadiene. GPC characterized by a number average molecular weight of 7100g/mol, a molecular weight distribution of 1.05, obtained by¹H NMR and¹³the product was characterized by C NMR, and from the results, it was found that the microstructure was 18.5%, 40.5%, 41% in cis-1, 4 structure, trans-1, 4 structure, and 1, 2-vinyl group, respectively, and the hydroxyl functionality was 2.5.

Example 3

In this example, a low cis, high ethylene-based hydroxyl polybutadiene rubber was prepared by the following preparation method:

the initiator preparation is the same as example 1, adding 4500g cyclohexane/n-hexane mixed solvent into a 10L reaction kettle, adding 1.35g THF (tetrahydrofuran) and TMEDA (tetramethylethylenediamine) preparation solution (prepared according to the mass ratio of 2: 1), starting stirring (150r/min), fully stirring, adding 32g the prepared bi/multifunctional chain extension initiator after the temperature reaches 40-45 ℃, stirring, adding 312.5g butadiene, controlling the temperature peak at 95-105 ℃ until the temperature does not rise for about 3min, adding 1.5g ethylene oxide for reaction for 15min, adding 1g water for hydrolysis reaction for 10min, introducing 20min carbon dioxide into the liquid hydroxyl-terminated polybutadiene glue solution, and adding tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]A combined antioxidant of pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite, the amount of the antioxidant added being 1.3phr, wherein tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]Adding pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite in a ratio of 1:1, and then vacuumizing to remove cyclohexane solvent to obtain pure liquid hydroxyl-terminated polybutadiene. The number average molecular weight is 11205g/mol and the molecular weight distribution is 1.05 by GPC characterization¹H NMR and¹³the product was characterized by C NMR, and from the results, it was found that the microstructure was 18.5%, 39.5%, 42% in cis-1, 4, trans-1, 4, 1, 2-vinyl, respectively, and the hydroxyl functionality was 2.5.

Example 4

In this example, a low cis, high ethylene-based hydroxyl polybutadiene rubber was prepared by the following preparation method:

initiator preparation as in example 1Adding 4500g of cyclohexane/n-hexane mixed solvent into a 10L reaction kettle, adding 1.35g of THF (tetrahydrofuran) and 2, 2-bis (2-tetrahydrofuryl) propane preparation solution (prepared according to the mass ratio of 1: 2), stirring (150r/min) fully, adding 32g of the prepared bi/multifunctional chain extension initiator after the temperature reaches 40-45 ℃, stirring uniformly, adding 312.5g of butadiene, controlling the temperature peak at 95-105 ℃ until the temperature does not rise for about 3min, adding 1.5g of ethylene oxide for reacting 15min, adding 1g of water for hydrolyzing for 10min, introducing 20min of carbon dioxide into the liquid hydroxyl-terminated polybutadiene glue solution, and adding tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]A combined antioxidant of pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite, the amount of the antioxidant added being 1.3phr, wherein tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid]Adding pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite in a ratio of 1:1, and then vacuumizing to remove cyclohexane solvent to obtain pure liquid hydroxyl-terminated polybutadiene. GPC characterized by a number average molecular weight of 13205g/mol, a molecular weight distribution of 1.05, obtained by¹H NMR and¹³the product was characterized by C NMR, and from the results, it was found that the microstructure was 11.5%, 20.5%, 68% in cis-1, 4 structure, 1, 2-vinyl group content, respectively, and the hydroxyl functionality was 2.7.

Example 5

The initiator preparation was the same as in example 1, adding 4500g of cyclohexane/n-hexane mixed solvent, 1.35g of 2, 2-bis (2-tetrahydrofuryl) propane and tetrahydrofurfuryl alcohol ethyl ether preparation (prepared at a mass ratio of 1: 2) into a 10L reaction kettle, stirring (150r/min) sufficiently and uniformly until the temperature reached 40-45 ℃, adding 32g of the prepared bi/multifunctional chain extension initiator, stirring uniformly, adding 312.5g of butadiene, controlling the temperature peak at 95-105 ℃ until the temperature does not rise for about 3min, adding 1.5g of ethylene oxide for reaction for 15min, adding 1g of water for hydrolysis reaction for 10min, introducing 20min of carbon dioxide into the liquid hydroxyl-terminated polybutadiene glue solution, and then adding tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid.]A combined antioxidant of pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite, the amount of the antioxidant added being 1.3phr, wherein tetrakis [ beta- (3, 5-bis-tert-butylphenyl) phosphiteTert-butyl-4-hydroxyphenyl) propionic acid]Adding pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite in a ratio of 1:1, and then vacuumizing to remove cyclohexane solvent to obtain pure liquid hydroxyl-terminated polybutadiene. GPC characterized by a number average molecular weight of 12155g/mol, a molecular weight distribution of 1.04¹H NMR and¹³the product was characterized by C NMR, and from the results, it was found that the microstructure was 10.5%, 17.0%, 72.5% in cis-1, 4 structure, trans-1, 4 structure, and 1, 2-vinyl group, respectively, and the hydroxyl functionality was 2.6.

The applicants state that the present invention is illustrated by the above examples for the preparation of the low cis, high ethylene-based hydroxyl polybutadiene rubber of the present invention, but the present invention is not limited to the above examples, i.e., it is not meant to be construed as being limited thereto. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.