阅读说明：本技术 一种溶聚丁苯橡胶的制备方法 (Preparation method of solution polymerized styrene-butadiene rubber ) 是由 谢晴 李立霞 韩飞 荆帅林 栾波 任学斌 王耀伟 于 2021-08-27 设计创作，主要内容包括：本发明提供了一种溶聚丁苯橡胶的制备方法,包括：S1)在保护气氛中,将苯乙烯、丁二烯、溶剂与有机锂混合进行聚合反应,得到胶液；S2)将所述胶液与溴化剂混合进行溴化反应,加入缚酸剂中和后水洗,静置分层,得到有机相；S3)将有机相、抗氧剂与稳定剂混合,除去溶剂,得到溶聚丁苯橡胶。与现有技术相比,本发明采用活性阴离子聚合技术制备溶聚丁苯橡胶的同时加入溴化剂,直接合成具有阻燃性能的溴化溶聚丁苯橡胶,溴化前无需脱除丁苯橡胶溶剂再溶解,达到简化溶聚丁苯橡胶工艺,降低能源消耗的目的,并且得到的溶聚丁苯橡胶具有优异的力学性能,从而增加溶聚丁苯橡胶产品应用范围。(The invention provides a preparation method of solution polymerized styrene butadiene rubber, which comprises the following steps: s1), mixing styrene, butadiene, a solvent and organic lithium in a protective atmosphere to perform a polymerization reaction to obtain a glue solution; s2) mixing the glue solution with a brominating agent for bromination reaction, adding an acid binding agent for neutralization, washing with water, standing for layering to obtain an organic phase; s3) mixing the organic phase, the antioxidant and the stabilizer, and removing the solvent to obtain the solution polymerized styrene-butadiene rubber. Compared with the prior art, the brominated solution-polymerized styrene-butadiene rubber with flame retardant property is directly synthesized by adding the brominating agent while preparing the solution-polymerized styrene-butadiene rubber by adopting the active anion polymerization technology, the styrene-butadiene rubber solvent is not required to be removed before bromination for redissolving, the purposes of simplifying the solution-polymerized styrene-butadiene rubber process and reducing the energy consumption are achieved, and the obtained solution-polymerized styrene-butadiene rubber has excellent mechanical property, so that the application range of the solution-polymerized styrene-butadiene rubber product is enlarged.)

1. A preparation method of solution polymerized styrene-butadiene rubber is characterized by comprising the following steps:

s1), mixing styrene, butadiene, a solvent and organic lithium in a protective atmosphere to perform a polymerization reaction to obtain a glue solution;

s2) mixing the glue solution with a brominating agent for bromination reaction, adding an acid binding agent for neutralization, washing with water, standing for layering to obtain an organic phase;

s3) mixing the organic phase, the antioxidant and the stabilizer, and removing the solvent to obtain the solution polymerized styrene-butadiene rubber.

2. The preparation method according to claim 1, wherein the mass of the styrene is 10-40% of the total mass of the styrene and the butadiene; the organic lithium is selected from n-butyl lithium; the mole number of the organic lithium is 0.02-0.06 percent of the total mole number of the styrene and the butadiene; the solvent is a cycloalkane.

3. The preparation method according to claim 1, wherein the temperature of the polymerization reaction in the step S1) is 50 ℃ to 60 ℃; the time of the polymerization reaction is 50-80 min.

4. The preparation method according to claim 1, wherein a terminating agent is added after the polymerization reaction to obtain a glue solution; the terminating agent is an alcohol solvent; the molar ratio of the terminating agent to the organic lithium is (0.3-2): 1.

5. the preparation method according to claim 1, wherein the brominating agent in step S2) is selected from Br₂One or more of HBr, N-bromosuccinimide, N-bromophthalic acid dimethylamide and N, N '-dibromo-5, 5' -dimethylhydantoin; the molar ratio of the brominating agent to the butadiene is (0.25-1.5): 1.

6. the preparation method according to claim 1, wherein the temperature of the bromination reaction in the step S2) is 45 to 55 ℃; the bromination reaction time is 10-60 min.

7. The preparation method according to claim 1, wherein the acid scavenger is selected from one or more of alkali metal hydroxide, alkali weak acid salt and bisulfite; adding an acid binding agent, and neutralizing for 5-15 min to make the pH value of the system greater than or equal to 7;

the antioxidant is selected from one or more of antioxidant 1135, antioxidant 1076 and antioxidant 1010; the stabilizer is selected from stearate and/or epoxidized soybean oil.

8. The solution polymerized styrene-butadiene rubber prepared by the preparation method of any one of claims 1 to 7.

9. The solution-polymerized styrene-butadiene rubber according to claim 8, wherein the solution-polymerized styrene-butadiene rubber has a molecular weight of 4.6 x 10⁴～2.5×10⁵The molecular weight distribution is 1.0-1.5; the solution polymerized styrene butadiene rubber contains 10-40 wt% of styrene structure, 50-80 wt% of 1,4 structure butadiene and 5-20 wt% of 1,2 structure butadiene.

10. The solution-polymerized styrene-butadiene rubber according to claim 9, comprising one or more of the structures of formulae (I) to (II):

Technical Field

The invention belongs to the technical field of rubber, and particularly relates to a preparation method of solution polymerized styrene butadiene rubber.

Background

The styrene butadiene rubber is a styrene butadiene copolymer synthesized by taking styrene and butadiene as monomers, has processing performance and product use performance which are closer to those of natural rubber, is more excellent than the natural rubber in the aspects of heat resistance, wear resistance, vulcanization speed, aging resistance and the like, and can be used together with the natural rubber and various other rubbers, so the styrene butadiene rubber has wide application in various production fields of adhesive tape rubber tubes, tires, wires and cables, medical appliances and the like, is a rubber product which realizes industrial production and manufacture earlier and is the largest synthetic rubber variety. However, the styrene butadiene rubber is extremely easy to burn, dense smoke and molten drops are generated during burning, and once the styrene butadiene rubber is ignited, serious fire accidents can be caused, so that the life and property of human beings are seriously threatened, and therefore, the improvement of the flame retardant property of the styrene butadiene rubber has important significance.

Flame-retardant styrene-butadiene rubber is generally obtained by two methods, one method is that a flame retardant is added into styrene-butadiene rubber for mixing processing to obtain a styrene-butadiene rubber product with a flame-retardant effect, for example, Chinese patents with publication numbers of CN104610608A and CN104610608A both add halogen-containing flame retardant into styrene-butadiene rubber to obtain a rubber material with a good flame-retardant effect, but when the flame-retardant effect is exerted, a large amount of smoke, toxic substances and corrosive gases are released, and the substances can pollute the environment and cause harm to the health of a human body; the flame-retardant styrene-butadiene rubber composition prepared by compounding halogen-free hydroxymethyl lignin, transition metal silicate and magnesium hydroxide with the flame-retardant styrene-butadiene rubber composition disclosed in the Chinese patent with the publication number of CN107118412A has good flame-retardant property and mechanical property, but the magnesium hydroxide is an inorganic substance and is poor in compatibility with styrene-butadiene rubber, so that the processing and forming are difficult. The other method is that a brominating agent reacts with styrene butadiene rubber, a bromine functional group is introduced to achieve the purpose of improving the flame retardant performance, in the prior art, the styrene butadiene rubber is generally redissolved, a solvent is halohydrocarbon (Chinese patent with publication number of CN 103059367A), but direct bromination in the styrene butadiene rubber synthesis process is not involved, the product structure is not regulated, the bromine content is more than 60%, butadiene double bonds almost completely react, the original performance of the styrene butadiene rubber is reduced, and the product is only suitable for a flame retardant.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a method for preparing solution-polymerized styrene-butadiene rubber with good flame retardancy.

The invention provides a preparation method of solution polymerized styrene butadiene rubber, which comprises the following steps:

s1), mixing styrene, butadiene, a solvent and organic lithium in a protective atmosphere to perform a polymerization reaction to obtain a glue solution;

s2) mixing the glue solution with a brominating agent for bromination reaction, adding an acid binding agent for neutralization, washing with water, standing for layering to obtain an organic phase;

s3) mixing the organic phase, the antioxidant and the stabilizer, and removing the solvent to obtain the solution polymerized styrene-butadiene rubber.

Preferably, the mass of the styrene is 10-40% of the total mass of the styrene and the butadiene; the organic lithium is selected from n-butyl lithium; the mole number of the organic lithium is 0.02-0.06 percent of the total mole number of the styrene and the butadiene; the solvent is a cycloalkane.

Preferably, the temperature of the polymerization reaction in the step S1) is 50-60 ℃; the time of the polymerization reaction is 50-80 min.

Preferably, adding a terminating agent after the polymerization reaction to obtain a glue solution; the terminating agent is an alcohol solvent; the molar ratio of the terminating agent to the organic lithium is (0.3-2): 1.

preferably, the brominating agent in the step S2) is selected from Br₂One or more of HBr, N-bromosuccinimide, N-bromophthalic acid dimethylamide and N, N '-dibromo-5, 5' -dimethylhydantoin; the molar ratio of the brominating agent to the butadiene is (0.25-1.5): 1.

preferably, the temperature of the bromination reaction in the step S2) is 45-55 ℃; the bromination reaction time is 10-60 min.

Preferably, the acid-binding agent is selected from one or more of alkali metal hydroxide, alkali weak acid salt and bisulfite; adding an acid binding agent, and neutralizing for 5-15 min to make the pH value of the system greater than or equal to 7;

the antioxidant is selected from one or more of antioxidant 1135, antioxidant 1076 and antioxidant 1010; the stabilizer is selected from stearate and/or epoxidized soybean oil.

The invention also provides the solution polymerized styrene-butadiene rubber prepared by the method.

Preferably, the solution-polymerized styrene-butadiene rubber has a molecular weight of 4.6 × 10⁴～2.5×10⁵The molecular weight distribution is 1.0-1.5; the solution polymerized styrene butadiene rubber contains 10-40 wt% of styrene structure, 50-80 wt% of 1,4 structure butadiene and 5-20 wt% of 1,2 structure butadiene.

Preferably, one or more of the structures of formula (I) to formula (II) are included:

the invention provides a preparation method of solution polymerized styrene butadiene rubber, which comprises the following steps: s1), mixing styrene, butadiene, a solvent and organic lithium in a protective atmosphere to perform a polymerization reaction to obtain a glue solution; s2) mixing the glue solution with a brominating agent for bromination reaction, adding an acid binding agent for neutralization, washing with water, standing for layering to obtain an organic phase; s3) mixing the organic phase, the antioxidant and the stabilizer, and removing the solvent to obtain the solution polymerized styrene-butadiene rubber. Compared with the prior art, the brominated solution-polymerized styrene-butadiene rubber with flame retardant property is directly synthesized by adding the brominating agent while preparing the solution-polymerized styrene-butadiene rubber by adopting the active anion polymerization technology, the styrene-butadiene rubber solvent is not required to be removed before bromination for redissolving, the purposes of simplifying the solution-polymerized styrene-butadiene rubber process and reducing the energy consumption are achieved, and the obtained solution-polymerized styrene-butadiene rubber has excellent mechanical property, so that the application range of the solution-polymerized styrene-butadiene rubber product is enlarged.

Drawings

FIG. 1 shows NMR spectra of solution-polymerized styrene-butadiene rubber obtained in examples 1 and 4 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a preparation method of solution polymerized styrene butadiene rubber, which comprises the following steps: s1), mixing styrene, butadiene, a solvent and organic lithium in a protective atmosphere to perform a polymerization reaction to obtain a glue solution; s2) mixing the glue solution with a brominating agent for bromination reaction, adding an acid binding agent for neutralization, washing with water, standing for layering to obtain an organic phase; s3) mixing the organic phase, the antioxidant and the stabilizer, and removing the solvent to obtain the solution polymerized styrene-butadiene rubber.

In the present invention, the sources of all raw materials are not particularly limited, and they may be commercially available.

Mixing styrene, butadiene, a solvent and organic lithium in a protective atmosphere to carry out polymerization reaction to obtain a glue solution; the protective atmosphere is not particularly limited as long as it is known to those skilled in the art, and nitrogen is preferred in the present invention; the mass of the styrene is preferably 10 to 40 percent, more preferably 20 to 40 percent, and even more preferably 30 to 40 percent of the total mass of the styrene and the butadiene; the solvent is preferably a cycloalkane, more preferably cyclohexane; the mass ratio of the total mass of styrene and butadiene to the solvent is preferably 1: (4-10), more preferably 1: (4-8), and more preferably 1: (5-6); the organolithium is preferably n-butyllithium; the mole number of the organic lithium is preferably 0.02 to 0.06 percent of the total mole number of the styrene and the butadiene, more preferably 0.03 to 0.05 percent, and still more preferably 0.04 percent; the temperature of the polymerization reaction is preferably 50-60 ℃, and more preferably 55 ℃; the time of the polymerization reaction is preferably 50-80 min, and more preferably 60-70 min; in the present invention, it is preferable that styrene, butadiene and a solvent are mixed in a protective atmosphere, heated to a polymerization temperature, and then organolithium is added to perform a polymerization reaction.

After the polymerization reaction is finished, preferably adding a terminator to obtain a glue solution; the terminating agent is an alcohol solvent, and more preferably one or more of ethanol, methanol, isopropanol, glycerol and triethylene glycol; the mol ratio of the terminating agent to the organic lithium is preferably (0.3-2): 1, more preferably (0.5 to 1.5): 1, more preferably (0.5 to 1.2): 1, more preferably (0.8 to 1.2): 1, most preferably 1: 1; the reaction time after adding the terminator is preferably 1-5 min.

Mixing the glue solution with a brominating agent for bromination reaction; the brominating agent is preferably Br₂One or more of HBr, N-bromosuccinimide, N-bromophthalic acid dimethylamide and N, N '-dibromo-5, 5' -dimethylhydantoin; the brominating agent can be added directly or in the form of a weak polar organic solvent solution, and is not particularly limited; the molar ratio of the brominating agent to butadiene is preferably (0.25-1.5): 1, more preferably (0.3 to 1.5): 1, more preferably (0.3 to 1.2): 1; in the embodiment provided by the present invention, the molar ratio of the brominating agent to butadiene is specifically 0.3: 1. 0.35: 1. 0.4:1 or 1.5: 1; the temperature of the bromination reaction is preferably 45-55 ℃; the time of the bromination reaction is preferably 10-60 min, more preferably 30-60 min, and still more preferably 50-60 min.

After bromination reaction, adding an acid binding agent for neutralization, washing with water, standing for layering to obtain an organic phase; the acid-binding agent is preferably one or more of alkali metal hydroxide, alkali weak acid salt and bisulfite, and is more preferably sodium hydroxide and/or potassium hydroxide; the acid scavenger is preferably added in the form of an aqueous solution thereof; the concentration of the acid-binding agent aqueous solution is preferably 0.5-2 wt%, and more preferably 1-2 wt%; the time for neutralization after the acid-binding agent is added is preferably 5-15 min, and more preferably 5-10 min; adding an acid binding agent for neutralization, and preferably enabling the pH value of the system to be more than or equal to 7; the water wash is preferably to neutral.

Mixing the organic phase, the antioxidant and the stabilizer, and removing the solvent; the mass of the antioxidant is preferably 0.1-0.5%, more preferably 0.2-0.4%, and even more preferably 0.3% of the total mass of the styrene and the butadiene; the antioxidant is preferably one or more of antioxidant 1135, antioxidant 1076 and antioxidant 1010; the mass of the stabilizer is preferably 1 to 5 percent of the total mass of the styrene and the butadiene, more preferably 1 to 3 percent, still more preferably 1 to 2 percent, and most preferably 1.5 percent; the stabilizer is preferably stearate and/or epoxidized soybean oil; the method of removing the solvent is preferably flash evaporation; the temperature for removing the solvent is preferably 85 to 98 ℃.

After the solvent is removed, the obtained rubber material is preferably extruded, dehydrated and dried to obtain solution polymerized styrene-butadiene rubber; the temperature of the extrusion dehydration is preferably 98-105 ℃, and more preferably 100 ℃; the time for the pressure dehydration is preferably 1-3 min, and more preferably 2 min; the press dewatering is preferably carried out in an open mill.

The brominated solution-polymerized styrene-butadiene rubber with flame retardant property is directly synthesized by adding the brominating agent while preparing the solution-polymerized styrene-butadiene rubber by adopting an active anion polymerization technology, and the styrene-butadiene rubber solvent does not need to be removed before bromination for redissolution, so that the purposes of simplifying the solution-polymerized styrene-butadiene rubber process and reducing energy consumption are achieved, and the obtained solution-polymerized styrene-butadiene rubber has excellent mechanical properties, thereby increasing the application range of the solution-polymerized styrene-butadiene rubber product.

The invention also provides the solution polymerized styrene-butadiene rubber prepared by the preparation method.

The molecular weight of the solution-polymerized styrene-butadiene rubber is preferably 4.6 x 10⁴～2.5×10⁵More preferably 1.5X 10⁵～2.0×10⁵(ii) a The molecular weight distribution is preferably 1.0-1.5, more preferably 1.1-1.3; the styrene structure content in the solution polymerized styrene-butadiene rubber is preferably 10-40 wt%, and more preferably 10-30 wt%; the content of 1, 4-structured butadiene is preferably 50 to 80 wt%, and more preferably 60 to 70 wt%; the content of 1, 2-structured butadiene is preferably 5 to 20 wt%, more preferably 10 to 15 wt%.

Further preferably, the solution-polymerized styrene-butadiene rubber comprises one or more of the structures of formula (I) to formula (II):

in order to further illustrate the present invention, the following examples are provided to describe the preparation method of a solution-polymerized styrene-butadiene rubber according to the present invention in detail.

The reagents used in the following examples are all commercially available.

Example 1

This example uses Br₂As brominating agent, Br₂The molar ratio of butadiene to butadiene is 0.3:1, and the specific implementation steps are as follows:

1.1 preparation of styrene butadiene random copolymer by living anionic polymerization: sealing a 500mL polymerization bottle under the protection of high-purity nitrogen, baking in vacuum and pumping for three times, adding 195g of cyclohexane solvent, 14.5g of styrene and 21.75g of butadiene, starting stirring, heating to 55 ℃, adding 0.14mL of n-butyl lithium solution (the concentration is 1.6mol/L), reacting for 60min, adding 0.34g of triethylene glycol, and stopping for 5min to obtain a glue solution.

1.2 taking 6.1ml of Br₂Adding the mixture into the glue solution obtained in the step 1.1, and stirring vigorously, wherein the bromination reaction temperature is 45 ℃, and the bromination reaction time is 60 min.

1.3 adding 1 wt% NaOH solution into the step 1.2, and reacting for 5min to ensure that the pH of the liquid system is more than or equal to 7.

1.4 washing the system obtained in the step 1.3 with deionized water until the pH value is approximately equal to 7, standing, layering and keeping an organic phase.

1.5 adding 0.11g of antioxidant 1135 and 0.54g of epoxidized soybean oil into the organic phase obtained in the step 1.4, and stirring to uniformly disperse the antioxidant and the stabilizer in the organic phase.

1.6 adding the system obtained in the step 1.5 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), and drying to obtain the finished product of the solution polymerized styrene butadiene rubber.

The solution-polymerized styrene-butadiene rubber obtained in example 1 was analyzed by nuclear magnetic resonance, and a nuclear magnetic hydrogen spectrum thereof was obtained as shown in FIG. 1. The nuclear magnetic hydrogen spectrum analysis of the finished product shows that only part of 1,4 structures of butadiene participate in the bromination reaction, and the structure of the obtained brominated solution polymerized butadiene styrene rubber is as follows:

example 2

This example uses Br₂As brominating agent, Br₂The molar ratio of butadiene to butadiene is 0.35:1, and the specific implementation steps are as follows:

2.1 preparation of styrene butadiene random copolymer by living anionic polymerization: sealing a 500mL polymerization bottle under the protection of high-purity nitrogen, baking in vacuum and pumping for three times, adding 195g of cyclohexane solvent, 14.5g of styrene and 21.75g of butadiene, starting stirring, heating to 55 ℃, adding 0.14mL of n-butyl lithium solution (the concentration is 1.6mol/L), reacting for 60min, adding 0.34g of triethylene glycol, and stopping for 5min to obtain a glue solution.

2.2 taking 7.1ml of Br₂Adding the mixture into the glue solution obtained in the step 2.1, and stirring vigorously, wherein the bromination reaction temperature is 45 ℃, and the bromination reaction time is 60 min.

2.3 adding 1 wt% NaOH solution into the step 2.2, and reacting for 5min to ensure that the pH of the liquid system is more than or equal to 7.

2.4 washing the system obtained in the step 2.3 with deionized water until the pH value is approximately equal to 7, standing, layering and keeping an organic phase.

2.5 adding 0.11g of antioxidant 1135 and 0.54g of epoxidized soybean oil into the organic phase obtained in the step 2.4, and stirring to uniformly disperse the antioxidant and the stabilizer in the organic phase.

2.6 adding the system obtained in the step 2.5 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), and drying to obtain the finished product of the solution polymerized styrene butadiene rubber.

The nuclear magnetic hydrogen spectrum analysis of the finished product shows that only part of 1,4 structures of the butadiene participate in the bromination reaction, and the structure of the obtained brominated solution polymerized butadiene styrene rubber is

Example 3

This example uses Br₂As brominating agent, Br₂The molar ratio of butadiene to butadiene is 0.4:1, and the specific implementation steps are as follows:

3.1 preparation of styrene butadiene random copolymer by living anionic polymerization: sealing a 500mL polymerization bottle under the protection of high-purity nitrogen, baking in vacuum and pumping for three times, adding 195g of cyclohexane solvent, 14.5g of styrene and 21.75g of butadiene, starting stirring, heating to 55 ℃, adding 0.14mL of n-butyl lithium solution (the concentration is 1.6mol/L), reacting for 60min, adding 0.34g of triethylene glycol, and stopping for 5min to obtain a glue solution.

3.2 taking 8.1ml of Br₂Adding the mixture into the glue solution obtained in the step 3.1, and stirring vigorously, wherein the bromination reaction temperature is 45 ℃, and the bromination reaction time is 60 min.

3.3 adding 1 wt% NaOH solution into the step 3.2, and reacting for 5min to ensure that the pH of the liquid system is more than or equal to 7.

3.4 washing the system obtained in the step 3.3 with deionized water until the pH value is approximately equal to 7, standing, layering and keeping an organic phase.

3.5 adding 0.11g of antioxidant 1135 and 0.54g of epoxidized soybean oil into the organic phase obtained in the step 3.4, and stirring to uniformly disperse the antioxidant and the stabilizer in the organic phase.

3.6 adding the system obtained in the step 3.5 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), and drying to obtain the finished product of the solution polymerized styrene butadiene rubber.

The nuclear magnetic hydrogen spectrum analysis of the finished product obtains that 1,4 structures of partial butadiene and 1,2 structures of partial butadiene both participate in bromination reaction, and the structure of the obtained brominated solution polymerized butadiene styrene rubber is

Example 4

This example uses Br₂As brominating agent, Br₂The molar ratio of butadiene to butadiene is 1.5:1, and the specific implementation steps are as follows:

4.1 preparation of styrene butadiene random copolymer by living anionic polymerization: sealing a 500mL polymerization bottle under the protection of high-purity nitrogen, baking in vacuum and pumping for three times, adding 195g of cyclohexane solvent, 14.5g of styrene and 21.75g of butadiene, starting stirring, heating to 55 ℃, adding 0.14mL of n-butyl lithium solution (the concentration is 1.6mol/L), reacting for 60min, adding 0.34g of triethylene glycol, and stopping for 5min to obtain a glue solution.

4.2 taking 31ml of Br₂Adding the mixture into the glue solution obtained in the step 3.1, and stirring vigorously, wherein the bromination reaction temperature is 45 ℃, and the bromination reaction time is 60 min.

4.3 adding 1 wt% NaOH solution into the step 4.2, and reacting for 5min to ensure that the pH of the liquid system is more than or equal to 7.

4.4 washing the system obtained in the step 4.3 with deionized water until the pH value is approximately equal to 7, standing, layering and keeping an organic phase.

4.5 adding 0.11g of antioxidant 1135 and 0.54g of epoxidized soybean oil into the organic phase obtained in the step 4.4, and stirring to uniformly disperse the antioxidant and the stabilizer in the organic phase.

4.6 adding the system obtained in the step 4.5 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), and drying to obtain the finished product of the solution polymerized styrene butadiene rubber.

The solution-polymerized styrene-butadiene rubber obtained in example 4 was analyzed by nuclear magnetic resonance, and a nuclear magnetic hydrogen spectrum thereof was obtained as shown in FIG. 1. The 1.4 structure and 1,2 structure of butadiene are obtained by nuclear magnetic hydrogen spectrum analysis of the finished product and are all reacted with bromination to obtain the brominated solution polymerized styrene-butadiene rubber with the structure of

Example 5

Br in examples 5 and 1₂The molar ratio of butadiene was the same, using a 3L reactorA mode amplification experiment was performed.

This example uses Br₂As brominating agent, Br₂The molar ratio of butadiene to butadiene is 0.3:1, and the specific implementation steps are as follows:

5.1 preparation of styrene butadiene random copolymer by living anionic polymerization: purging a 3L reaction kettle by using high-purity nitrogen, adding 975g of cyclohexane solvent, 72.5g of styrene and 108.75g of butadiene, starting stirring, increasing the temperature to 55 ℃, adding 0.7mL of n-butyllithium solution (the concentration is 1.6mol/L), reacting for 60min, adding 1.7g of triethylene glycol, and stopping for 5min to obtain a glue solution.

5.2 taking 30.5ml of Br₂Adding the obtained product into the glue solution obtained in the step 5.1, and stirring vigorously, wherein the bromination reaction temperature is 45 ℃, and the bromination reaction time is 60 min.

5.3 adding 1 wt% NaOH solution into the step 5.2, and reacting for 5min to ensure that the pH of the liquid system is more than or equal to 7.

5.4 washing the system obtained in the step 5.3 with deionized water until the pH value is approximately equal to 7, standing, layering and keeping an organic phase.

5.5 adding 0.55g of antioxidant 1135 and 2.7g of epoxidized soybean oil into the organic phase obtained in the step 5.4, and stirring to uniformly disperse the antioxidant and the stabilizer in the organic phase.

5.6 adding the system obtained in the step 5.5 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), and drying to obtain the finished product of the solution polymerized styrene butadiene rubber.

The resulting product was structurally the same as example 1 and was subjected to performance evaluation.

Example 6

Br in examples 6 and 3₂A mode amplification experiment was performed using a 3L reactor at the same molar ratio as butadiene.

This example uses Br₂As brominating agent, Br₂The molar ratio of butadiene to butadiene is 0.4:1, and the specific implementation steps are as follows:

6.1 preparation of styrene butadiene random copolymer by living anionic polymerization: purging a 3L reaction kettle by using high-purity nitrogen, adding 975g of cyclohexane solvent, 72.5g of styrene and 108.75g of butadiene, starting stirring, increasing the temperature to 55 ℃, adding 0.7mL of n-butyllithium solution (the concentration is 1.6mol/L), reacting for 60min, adding 1.7g of triethylene glycol, and stopping for 5min to obtain a glue solution.

6.2 taking 40.5ml of Br₂And (3) adding the mixture into the glue solution obtained in the step (6.1) and stirring vigorously, wherein the bromination reaction temperature is 45 ℃, and the bromination reaction time is 60 min.

6.3 adding 1 wt% NaOH solution into the step 6.2, and reacting for 5min to ensure that the pH of the liquid system is more than or equal to 7.

6.4 washing the system obtained in the step 6.3 with deionized water until the pH value is approximately equal to 7, standing, layering and keeping an organic phase.

6.5 adding 0.55g of antioxidant 1135 and 2.7g of epoxidized soybean oil into the organic phase obtained in the step 6.4, and stirring to uniformly disperse the antioxidant and the stabilizer in the organic phase.

6.6 adding the system obtained in the step 6.5 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), and drying to obtain the finished product of the solution polymerized styrene butadiene rubber.

The resulting product was structurally the same as example 3 and was subjected to performance evaluation.

Example 7

Br in examples 7 and 4₂A mode amplification experiment was performed using a 3L reactor at the same molar ratio as butadiene.

This example uses Br₂As brominating agent, Br₂The molar ratio of butadiene to butadiene is 1.5:1, and the specific implementation steps are as follows:

7.1 preparation of styrene butadiene random copolymer by living anionic polymerization: purging a 3L reaction kettle by using high-purity nitrogen, adding 975g of cyclohexane solvent, 72.5g of styrene and 108.75g of butadiene, starting stirring, increasing the temperature to 55 ℃, adding 0.7mL of n-butyllithium solution (the concentration is 1.6mol/L), reacting for 60min, adding 1.7g of triethylene glycol, and stopping for 5min to obtain a glue solution.

7.2 taking 155ml of Br₂Adding the obtained product into the glue solution obtained in the step 7.1, and stirring vigorously, wherein the bromination reaction temperature is 45 ℃, and the bromination reaction time is 60 min.

7.3 adding 1 wt% NaOH solution into the step 7.2, and reacting for 5min to ensure that the pH of the liquid system is more than or equal to 7.

7.4 washing the system obtained in the step 7.3 with deionized water until the neutral pH is approximately equal to 7, standing, layering and keeping an organic phase.

7.5 adding 0.55g of antioxidant 1135 and 2.7g of epoxidized soybean oil into the organic phase obtained in the step 7.4, and stirring to uniformly disperse the antioxidant and the stabilizer in the organic phase.

7.6 adding the system obtained in the step 7.5 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), and drying to obtain the finished product of the solution polymerized styrene butadiene rubber.

The resulting product was structurally the same as example 4 and was subjected to performance evaluation.

Comparative example 1

1.1 preparation of styrene butadiene random copolymer by living anionic polymerization: A3L reactor was purged with high-purity nitrogen, 975g of a cyclohexane solvent, 72.5g of styrene and 108.75g of butadiene were added, stirring was started, the temperature was raised to 55 ℃, 0.7mL of an n-butyllithium solution (1.6 mol/L concentration) was added, and after 60 minutes of reaction, 1.7g of triethylene glycol was added, and the reaction was terminated for 5 minutes.

1.2 adding the system obtained in the step 1.1 into hot water at 98 ℃ for flash evaporation to remove the solvent, taking out the product, extruding and dehydrating the product on an open mill (100 ℃ for 2min), drying the product to obtain the finished solution polymerized styrene-butadiene rubber, and evaluating the performance of the finished solution polymerized styrene-butadiene rubber.

The results of the microstructure, molecular weight and molecular weight distribution tests are shown in table 1.

Examples the results of the performance evaluation tests are shown in table 2.

TABLE 1 microstructure, molecular weight and molecular weight distribution test results

Table 2 evaluation of properties test results

Note: the basic formulation (parts by mass) (see ASTM D3185) was rubber 100, carbon black 50, zinc oxide 3.0, stearic acid 1.0, accelerator TBBS1.0, sulfur 1.75.

The nuclear magnetic resonance is tested by an AV-600 type NMR analyzer of Bruker company in Germany, deuterated chloroform is used as a solvent, and tetramethylsiloxane is used as an internal standard; gel chromatography was measured using a model 1525 GPC analyzer from Watars corporation, usa; mooney viscosity was measured according to GB/T1232.1-2000, vulcanization characteristics were measured according to GB/T16584-1996, tensile properties were measured according to GB/T528-2009, and limiting oxygen index was measured according to GB/T2406-2009.

The performance evaluation test results show that the Mooney property is gradually reduced, the vulcanization speed is increased and the flame retardant property is improved along with the increase of the bromination degree of the solution-polymerized styrene-butadiene rubber, wherein the solution-polymerized styrene-butadiene rubber prepared in the embodiment 5 has excellent mechanical property and good flame retardant property.