阅读说明：本技术 无规集成橡胶的制备方法 (Preparation method of random integrated rubber ) 是由 徐炜 王雪 呼振鹏 王爱东 周微频 于 2019-10-30 设计创作，主要内容包括：本发明涉及聚合物合成领域,公开了一种无规集成橡胶的制备方法,该方法包括：在惰性溶剂和有机锂引发剂存在下,将丁二烯单体、异戊二烯单体和苯乙烯单体形成的混合物料进行间歇聚合反应,其中,控制所述混合物料的进料速度,使得所述混合物料在10-40min加完,并且,所述间歇聚合反应的引发温度为30-60℃。根据本发明提供的方法得到的集成橡胶具有无规分布的特点,从而使得其应用性能更为优异；而且不必须加入调节剂或是必须采用高温聚合工艺,从而可以节约生产成本。(The invention relates to the field of polymer synthesis, and discloses a preparation method of random integrated rubber, which comprises the following steps: in the presence of an inert solvent and an organic lithium initiator, carrying out batch polymerization reaction on a mixed material formed by a butadiene monomer, an isoprene monomer and a styrene monomer, wherein the feeding speed of the mixed material is controlled so that the mixed material is added in 10-40min, and the initiation temperature of the batch polymerization reaction is 30-60 ℃. The integrated rubber obtained by the method provided by the invention has the characteristic of random distribution, so that the application performance of the integrated rubber is more excellent; and no regulator is needed to be added or a high-temperature polymerization process is needed, so that the production cost can be saved.)

1. A method of preparing a randomly integrated rubber, the method comprising: in the presence of an inert solvent and an organic lithium initiator, carrying out batch polymerization reaction on a mixed material formed by a butadiene monomer, a styrene monomer and an isoprene monomer, wherein the feeding speed of the mixed material is controlled so that the mixed material is added in 10-40min, and the initiation temperature of the batch polymerization reaction is 30-60 ℃.

2. The method of claim 1, wherein the feed rate of the mixed material is controlled such that the butadiene monomer and the styrene monomer, isoprene monomer are added over 15-30 min.

3. The process according to claim 1 or 2, wherein the initiation temperature of the batch polymerization reaction is 40-50 ℃.

4. The method according to any one of claims 1 to 3, wherein the mass ratio of the styrene monomer, the isoprene monomer and the butadiene monomer is 1: 1-2: 1.5-10.

5. The method according to any one of claims 1-3, wherein the method further comprises: after the batch polymerization reaction is completed, a coupling agent is added to the reaction system to perform a coupling reaction.

6. The process according to claim 5, wherein the molar ratio of the coupling agent to the organolithium initiator, calculated as lithium element, is from 0.05 to 0.45: 1, preferably 0.15 to 0.30: 1.

7. the method of claim 5 or 6, wherein the method further comprises: carrying out termination reaction on the system obtained after the coupling reaction is carried out, and adding an anti-aging agent into the system;

preferably, the anti-aging agent is selected from at least one of anti-aging agent 264, anti-aging agent 1076, anti-aging agent 1010 and anti-aging agent 1520.

8. The process of any one of claims 1-7, wherein the inert solvent is selected from at least one of cyclohexane, n-hexane, n-heptane, and cyclopentane.

9. The process according to any one of claims 1 to 7, wherein the inert solvent is present in a weight ratio of 5 to 9: 1 of cyclohexane and n-hexane.

10. The method of any one of claims 1-9, wherein the method further comprises: controlling the feed rate of the mixed materials so that the peak temperature of the batch polymerization reaction is not higher than 90 ℃; preferably not higher than 85 deg.c.

Technical Field

The invention relates to the field of polymer synthesis, in particular to a preparation method of random integrated rubber.

Background

The integrated rubber SIBR is a ternary integrated synthetic rubber, contains structural units of natural rubber, styrene-butadiene rubber and butadiene rubber, obtains the advantages of the three rubbers, avoids the respective defects of the three rubbers, and meets the requirements of rolling resistance, wet skid resistance and wear resistance of the tire on the performance of tread rubber, so that a better application effect in a high-performance tire can be obtained.

In the research of the SIBR, Goodyear corporation of America is the most active research, and the synthesized SIBR has linear SIBR and star-shaped SIBR, and the chain segment distribution is random and block. Goodyear corporation has produced an integrated rubber product having a SIBR monomer ratio of S/I/B25/50/25 and a Mooney viscosity of 80, and has been applied to non-skid, low noise, high performance green tire tires. In addition to the use of the SIBR single rubber, the Goodyear company improves the wet skid resistance of the tread rubber and reduces the rolling resistance, and has a plurality of combined researches with other rubber varieties, and the use of the SIBR/BR/NR 70/20/10 in the tread rubber can ensure that the wet skid resistance and the wear resistance of the rubber can reach good balance; compared with the general rubber compound, the SIBR/NR 90/10 applied to the car tire tread rubber can obviously improve the wet skid resistance of the rubber compound and reduce the rolling resistance.

From the application of the solution polymerized styrene butadiene rubber products in the current domestic and foreign markets, the random solution polymerized styrene butadiene rubber with low vinyl and low styrene content is a product with characteristics, and can be applied to the tire tread rubber with special requirements on rolling resistance and wear resistance.

At present, the synthesis method of the low-styrene low-vinyl random solution polymerized styrene-butadiene rubber is generally to add a structure regulator or carry out polymerization under high temperature conditions. For example, CN102344530A uses a two-component regulator to synthesize a high vinyl solution-polymerized styrene-butadiene rubber with random distribution.

Disclosure of Invention

The object of the present invention is to provide a novel process for preparing an integral rubber having a random distribution without having to add regulators or having to carry out polymerization at high temperatures, while ensuring a monomer conversion of 100%, in order to obtain a randomly integral rubber having a low block content of styrene structural units.

In order to achieve the above object, the present invention provides a method for preparing a randomly integrated rubber, comprising: in the presence of an inert solvent and an organic lithium initiator, carrying out batch polymerization reaction on a mixed material formed by a butadiene monomer, an isoprene monomer and a styrene monomer, wherein the feeding speed of the mixed material is controlled so that the mixed material is added in 10-40min, and the initiation temperature of the batch polymerization reaction is 30-60 ℃.

The invention can obtain the integrated rubber with randomly distributed low styrene and low vinyl by specifically controlling the feeding time without adding a regulator or carrying out polymerization reaction at high temperature, and has the characteristic that the monomer conversion rate is 100 percent.

Further, the method of the invention also has the advantage of saving production cost.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

As previously mentioned, the present invention provides a method of synthesizing a randomly integrated rubber, the method comprising: in the presence of an inert solvent and an organic lithium initiator, carrying out batch polymerization reaction on a mixed material formed by a butadiene monomer, an isoprene monomer and a styrene monomer, wherein the feeding speed of the mixed material is controlled so that the mixed material is added in 10-40min, and the initiation temperature of the batch polymerization reaction is 30-60 ℃.

In order to make the block content of styrene lower in the randomly integrated rubber obtained by the process of the present invention, it is preferable to control the feed rate of the mixed material so that the butadiene monomer and the styrene monomer, isoprene monomer are added over 15 to 30 min.

Preferably, the initiation temperature of the batch polymerization reaction is 40 to 50 ℃. That is, the batch polymerization in the process of the present invention is conducted at an initiation temperature of 40 to 50 ℃ to obtain a low styrene low vinyl integral rubber having a random distribution.

Preferably, the mass ratio of the styrene monomer, the isoprene monomer and the butadiene monomer is 1: 1-2: 1.5-10; more preferably, the mass ratio of the styrene monomer, the isoprene monomer and the butadiene monomer is 1: 1.3-1.5: 2-8.

According to the invention, the temperature of the batch polymerization reaction is preferably between 30 and 90 ℃, preferably between 40 and 80 ℃; the time of the batch polymerization reaction is 10-70min, preferably 10-30 min; the pressure of the batch polymerization is 0.1 to 0.3MPa, preferably 0.1 to 0.2 MPa. In the present invention, the "pressure" refers to gauge pressure.

According to a preferred embodiment, the method further comprises: after the batch polymerization reaction is completed, a coupling agent is added to the reaction system to perform a coupling reaction.

In the present invention, the completion of the batch polymerization reaction is marked by the fact that the contents of butadiene monomer, isoprene monomer and styrene monomer in the reaction system are all less than 1% by weight. The above content test can be carried out, for example, by nuclear magnetism or the like.

According to the present invention, the organolithium initiator may be any of various organomonolithium compounds, organodilithium compounds or organopolylithium compounds capable of initiating olefin polymerization, which are generally used in the field of anionic polymerization, and is not particularly limited. The organolithium initiator is preferably an organomonolithium compound, more preferably a compound represented by formula (III),

R₃li type (III)

In the formula (III), R₃Is C₁-C₆Alkyl of (C)₃-C₁₂Cycloalkyl of, C₇-C₁₄Aralkyl or C₆-C₁₂Aryl group of (1).

Said C is₁-C₆Alkyl of (2) includes C₁-C₆Straight chain alkyl of (2) and C₃-C₆Specific examples thereof may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl and n-hexyl.

Said C is₃-C₁₂Specific examples of the cycloalkyl group of (a) may include, but are not limited to: cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-n-propylcyclohexyl and 4-n-butylcyclohexyl.

Said C is₇-C₁₄Specific examples of the aralkyl group of (a) may include, but are not limited to: phenylmethyl, phenylethyl, phenyl-n-propyl, phenyl-n-butyl, phenyl-t-butyl, phenyl-isopropyl, phenyl-n-pentyl and phenyl-n-butyl.

Said C is₆-C₁₂Specific examples of the aryl group of (a) may include, but are not limited to: phenyl, naphthyl, 4-methylphenyl and 4-ethylphenyl.

The organolithium initiator may specifically be, but is not limited to: one or more of ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, phenyllithium, 2-naphthyllithium, 4-butylphenyllithium, 4-tolyllithium, cyclohexyllithium, and 4-butylcyclohexyllithium, preferably n-butyllithium and/or sec-butyllithium, and more preferably n-butyllithium.

According to the present invention, preferably, the organolithium initiator is used in an amount of 0.1 to 5mmol in terms of lithium per 100g of the total amount of monomers, which is the sum of the styrene monomer, the isoprene monomer and the butadiene monomer.

In the present invention, the organolithium initiator is preferably added at once.

The present invention is not particularly limited with respect to the specific kind of the coupling agent, and various kinds of coupling agents conventionally used in the art may be employed, for example, one or more of methyltrichlorosilane, dimethyldichlorosilane, silicon tetrachloride and tin tetrachloride; preferably silicon tetrachloride. A coupling agent is exemplified in the examples of the present invention, and those skilled in the art should not be construed as limiting the present invention.

Preferably, the molar ratio of the coupling agent to the organic lithium initiator calculated on the lithium element is 0.05-0.45: 1, more preferably 0.15 to 0.30: 1.

according to another preferred embodiment, the method further comprises: and (3) carrying out termination reaction on the system obtained after the coupling reaction, and adding an anti-aging agent into the system.

The specific operation for carrying out the termination reaction in the present invention is not particularly limited, and the termination reaction can be carried out by various methods which are conventional in the art, for example, by introducing an appropriate amount of water or an alcohol (e.g., isopropyl alcohol) into the system. The reaction time can be 5-30min, and the reaction temperature can be 50-80 ℃. In addition, the terminating agent is used in an amount such that the molar ratio of the terminating agent to lithium in the organolithium initiator is 0.5 to 5: 1.

Preferably, the anti-aging agent is selected from at least one of anti-aging agent 264, anti-aging agent 1076, anti-aging agent 1010 and anti-aging agent 1520.

According to the present invention, the antioxidant may be used in an amount conventionally used in the art. For example, the antioxidant may be used in an amount of 0.005 to 2% by weight, preferably 0.1 to 0.5% by weight, based on the weight of the integral rubber.

According to the present invention, after the anti-aging agent is added, the random integral rubber can be precipitated from the solution by methods such as purification precipitation, centrifugal separation, filtration, decantation, hot water coagulation and the like, and the solvent in the reaction system can also be removed by a gas stripping method, which is known to those skilled in the art and will not be described herein again.

Preferably, the inert solvent is at least one selected from cyclohexane, n-hexane, n-heptane and cyclopentane.

In order to make the block content of styrene lower in the randomly integrated rubber obtained by the process of the present invention, it is preferred that the inert solvent is a mixture of 5 to 9: 1 of cyclohexane and n-hexane.

Furthermore, it is well known to those skilled in the art that trace amounts of water may be present in the solvent. However, since water is a terminator of anionic polymerization and can terminate the chain extension reaction by proton transfer, it is preferable to remove water from the solvent in the present invention in order to smoothly proceed the polymerization reaction. The water removal method can be to add a water removal agent into the solvent. The type of water scavenger is well known to those skilled in the art and may be, for example, a 5A molecular sieve available from gangkangkangyu chemical company, ltd.

According to a particularly preferred embodiment, the method of the invention further comprises: controlling the feed rate of the mixed materials so that the peak temperature of the batch polymerization reaction is not higher than 90 ℃; more preferably not higher than 85 deg.c. That is, the process of the present invention need not be carried out at elevated temperatures.

The peak temperature described herein represents the highest temperature tested during a batch polymerization reaction.

Also, the process of the present invention is preferably carried out under pressure conditions greater than atmospheric pressure. The pressure referred to in the following description of the present invention indicates gauge pressure unless otherwise specified.

According to a particularly preferred embodiment, the method of the invention comprises:

in the presence of an inert solvent and an organic lithium initiator, carrying out batch polymerization reaction on a mixed material formed by a butadiene monomer, an isoprene monomer and a styrene monomer, wherein the feeding speed of the mixed material is controlled so that the mixed material is added in 10-40min, and the initiation temperature of the batch polymerization reaction is 30-60 ℃; after the batch polymerization reaction is completed, adding a coupling agent into the reaction system to perform a coupling reaction; and then, carrying out termination reaction on the system obtained after the coupling reaction, and adding an anti-aging agent into the system.

The random integrated rubber obtained by the method has the number average molecular weight of 20-40 ten thousand and the molecular weight distribution of 1.30-1.60; preferably, the randomly integrated rubber has a number average molecular weight of typically 23 to 25 ten thousand and a molecular weight distribution of 1.40 to 1.50.

Also, the block content of the styrene structural unit in the randomly integrated rubber obtained by the method of the present invention is usually 0.01 to 0.2% by weight, preferably 0.07 to 0.14% by weight; the nonblock content of styrene structural units is generally from 12 to 18% by weight, preferably from 14 to 15% by weight; the content of vinyl structural units is generally from 10 to 20% by weight, preferably from 12 to 13% by weight.

The present invention will be described in detail below by way of examples. In the following examples and comparative examples, various raw materials used are commercially available ones unless otherwise specified.

In the following examples and comparative examples, the number average molecular weight and the molecular weight distribution of the polymer product were measured by using a Gel Permeation Chromatograph (GPC) of model LC-10AT from Shimadzu corporation, in which tetrahydrofuran was used as a mobile phase, narrow-distribution polystyrene was used as a standard, and the test temperature was 25 ℃.

In both the following examples and comparative examples, the solvent was soaked with a 5A molecular sieve (phi. 3X 5, available from Daliankang chemical Co., Ltd., previously baked at 500 ℃ for 5 hours) for 1 week before the solvent was applied.

In the following examples and comparative examples, the conversions were measured for all monomers and were calculated as: conversion ═ 100% by weight (weight of initial total monomers-weight of remaining total monomers)/weight of initial total monomers

In the following examples and comparative examples, the block content and vinyl content of the copolymer were measured by AVANCE DRX 400MHz NMR spectrometer of Bruker, Switzerland, and a sample was dissolved in deuterated chloroform (containing 1% of TMS) at room temperature to prepare a 2-3% (w/v) solution, and chemical shifts were calculated using TMS as a zero calibration, and the measurement was carried out at room temperature.

Example 1

2500g of a mixed solvent (cyclohexane and n-hexane in a weight ratio of 88: 12) and 20ml of an n-butyllithium solution (n-butyllithium concentration: 0.1437mol/L) were sequentially charged into a 5-liter polymerization vessel under a nitrogen atmosphere. The temperature is raised to 40 ℃, and the reaction pressure is 0.1 MPa. After mixing 37g of styrene, 56g of isoprene and 281g of butadiene, slowly feeding the mixture into a polymerization kettle, and controlling the feeding speed so that the mixture is added within 15 minutes, and after the mixture is added, the mixture is continuously reacted for 15 minutes to reach the peak temperature of 75 ℃, wherein the reaction pressure is 0.30 MPa. A sample was taken 10 minutes after the peak temperature to determine that the conversion reached 100%, at which time the reaction pressure was 0.18 MPa. Then 10ml (0.043mol/L) of silicon tetrachloride solution is added into the reaction kettle to continue the reaction, and after the reaction is carried out for 10 minutes, 0.5ml of isopropanol is added to stop the reaction. After stirring for 15 minutes, 3.0g of the antioxidant 2, 6-di-tert-butyl-p-methylphenol was added.

And (3) coagulating the glue solution by water vapor, and drying by an open mill to obtain a polymerization product. The microstructure of the product was measured and is shown in Table 1.

Example 2

2500g of a mixed solvent (cyclohexane and n-hexane in a weight ratio of 85: 15) and 20ml of an n-butyllithium solution (n-butyllithium concentration: 0.1437mol/L) were sequentially charged into a 5-liter polymerization vessel under a nitrogen atmosphere. The temperature is raised to 45 ℃, and the reaction pressure is 0.1 MPa. 56g of styrene, 75g of isoprene and 243g of butadiene are mixed and slowly fed into a polymerization kettle, the feeding speed is controlled, the mixture is added within 20 minutes, and the reaction is continued for 10 minutes after the addition, so that the peak temperature is 73 ℃, and the reaction pressure is 0.30MPa at this time. A sample was taken 10 minutes after the peak temperature to determine that the conversion reached 100%, at which time the reaction pressure was 0.18 MPa. Then 10ml (0.043mol/L) of silicon tetrachloride solution is added into the reaction kettle to continue the reaction, and after the reaction is carried out for 10 minutes, 0.5ml of isopropanol is added to stop the reaction. After stirring for 15 minutes, 3.0g of the antioxidant 2, 6-di-tert-butyl-p-methylphenol was added.

And (3) coagulating the glue solution by water vapor, and drying by an open mill to obtain a polymerization product. The microstructure of the product was determined and is shown in Table 1.

Example 3

2500g of a mixed solvent (cyclohexane and n-hexane in a weight ratio of 90: 10) and 20ml of an n-butyllithium solution (n-butyllithium concentration: 0.1437mol/L) were sequentially charged into a 5-liter polymerization vessel under a nitrogen atmosphere. The temperature is raised to 50 ℃, and the reaction pressure is 0.1 MPa. 75g of styrene, 112g of isoprene and 187g of butadiene are mixed and slowly fed into a polymerization kettle, the feeding speed is controlled, the mixture is added within 25 minutes, and the reaction pressure reaches 0.30MPa when the peak temperature is 70 ℃ after the reaction is carried out for 8 minutes. A sample was taken 10 minutes after the peak temperature to determine that the conversion reached 100%, at which time the reaction pressure was 0.18 MPa. Then 10ml (0.043mol/L) of silicon tetrachloride solution is added into the reaction kettle to continue the reaction, and after the reaction is carried out for 10 minutes, 0.5ml of isopropanol is added to stop the reaction. After stirring for 15 minutes, 3.0g of the antioxidant 2, 6-di-tert-butyl-p-methylphenol was added.

And (3) coagulating the glue solution by water vapor, and drying by an open mill to obtain a polymerization product. The microstructure of the product was determined and is shown in Table 1.

Example 4

This example was carried out in a similar manner to example 1, except that the mixture of styrene, isoprene and butadiene in this example was added in 30 minutes. The remaining operating conditions were the same as in example 1.

The microstructure of the product obtained in this example is shown in Table 1.

Example 5

This example was carried out in a similar manner to example 1, except that the mixture of styrene and butadiene and isoprene monomers in this example was added in 40 minutes. The remaining operating conditions were the same as in example 1.

The microstructure of the product obtained in this example is shown in Table 1.

Comparative example 1

This comparative example was carried out in a similar manner to example 1, except that: styrene, isoprene and butadiene were all added to the reaction system at the start of the reaction, specifically as follows:

2500g of a mixed solvent (cyclohexane and n-hexane in a weight ratio of 88: 12), 37g of styrene, 56g of isoprene, 281g of butadiene and 20ml of an n-butyllithium solution (the concentration of n-butyllithium is 0.1437mol/L) were sequentially added to a 5-liter polymerization reactor under the protection of nitrogen. The initiation temperature of the polymerization reaction was 40 ℃ and the reaction pressure was 0.3 MPa. After 15 minutes of reaction, a peak temperature of 80 ℃ was reached, at which time the reaction pressure was 0.38 MPa. A sample was taken 10 minutes after the peak temperature to determine that the conversion reached 100%, at which time the reaction pressure was 0.25 MPa. Then 10ml (0.043mol/L) of silicon tetrachloride solution is added into the reaction kettle to continue the reaction, and after the reaction is carried out for 10 minutes, 0.5ml of isopropanol is added to stop the reaction. After stirring for 15 minutes, 3.0g of the antioxidant 2, 6-di-tert-butyl-p-methylphenol was added.

And (3) coagulating the glue solution by water vapor, and drying by an open mill to obtain a polymerization product. The microstructure of the product was determined and is shown in Table 1.

Comparative example 2

This comparative example was carried out in a similar manner to example 2, except that: styrene, isoprene and butadiene were all added to the reaction system at the start of the reaction, specifically as follows:

2500g of a mixed solvent, 56g of styrene, 75g of isoprene and 243g of butadiene were sequentially charged into a 5-liter polymerization vessel under a nitrogen atmosphere, and 20ml of an n-butyllithium solution (the concentration of n-butyllithium was 0.1437mol/L) was added to conduct polymerization. The initiation temperature of the polymerization reaction was 45 ℃ and the reaction pressure was 0.3 MPa. After 15 minutes of reaction, a peak temperature of 89 ℃ was reached, at which time the reaction pressure was 0.41 MPa. A sample was taken 10 minutes after the peak temperature to determine that the conversion reached 100%, at which time the reaction pressure was 0.29 MPa. Then 10ml (0.043mol/L) of silicon tetrachloride solution is added into the reaction kettle to continue the reaction, and after the reaction is carried out for 10 minutes, 0.5ml of isopropanol is added to stop the reaction. After stirring for 15 minutes, 3.0g of the antioxidant 2, 6-di-tert-butyl-p-methylphenol was added.

And (3) coagulating the glue solution by water vapor, and drying by an open mill to obtain a polymerization product. The microstructure of the product was determined and is shown in Table 1.

Comparative example 3

This comparative example was carried out in a similar manner to example 3, except that: styrene, isoprene and butadiene were all added to the reaction system at the start of the reaction, specifically as follows:

2500g of a mixed solvent, 75g of styrene, 112g of isoprene and 187g of butadiene were sequentially charged into a 5-liter polymerization vessel under a nitrogen atmosphere, and 20ml of an n-butyllithium solution (the concentration of n-butyllithium was 0.1437mol/L) was added to conduct polymerization. The polymerization initiation temperature was 50 ℃ and the reaction pressure was 0.3 MPa. After 15 minutes of reaction, a peak temperature of 85 ℃ was reached, at which time the reaction pressure was 0.37 MPa. A sample was taken 10 minutes after the peak temperature to determine that the conversion reached 100%, at which time the reaction pressure was 0.24 MPa. Then 10ml (0.043mol/L) of silicon tetrachloride solution is added into the reaction kettle to continue the reaction, and after the reaction is carried out for 10 minutes, 0.5ml of isopropanol is added to stop the reaction. After stirring for 15 minutes, 3.0g of the antioxidant 2, 6-di-tert-butyl-p-methylphenol was added.

And (3) coagulating the glue solution by water vapor, and drying by an open mill to obtain a polymerization product. The microstructure of the product was determined and is shown in Table 1.

Comparative example 4

This comparative example was conducted in a similar manner to example 1, except that the mixture of styrene and butadiene and isoprene monomers in this comparative example was added over 2 minutes. The remaining operating conditions were the same as in example 1.

The microstructure of the product obtained in this example is shown in Table 1.

TABLE 1

From the results in table 1, it can be seen that the integrated rubber obtained by the method provided by the present invention has the characteristic of random distribution, and can achieve the excellent effect of low block content of styrene structural units on the premise of ensuring that the monomer conversion rate is 100%, so that the application performance is more excellent.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.