Macromolecular dilithium initiator as well as preparation method and application thereof

Abstract

The invention provides a macromolecular dilithium initiator as well as a preparation method and application thereof, and the preparation method of the macromolecular dilithium initiator comprises the following steps: S100, reacting an amine monomer with an organic lithium initiator in a solvent to obtain an amine lithium initiator solution; s200, adding a conjugated olefin monomer into the amine lithium initiator solution for reaction to obtain a macromolecular monolithium initiator solution; s300, adding divinyl aromatic hydrocarbon into the macromolecular monolithium initiator solution for reaction to obtain a macromolecular dilithium initiator; a long olefin chain is introduced into the macromolecular double-lithium initiator, so that the oil solubility of the double-lithium initiator is remarkably improved, the double-lithium initiator has higher stability and polymerization activity, an amino functional group is introduced into the macromolecular double-lithium initiator, and the method for preparing SSBR by using the macromolecular double-lithium initiator not only can enhance the interfacial force between the SSBR and carbon black or white carbon black, but also can improve the stability of the SSBR. And the dispersion mixing property of the SSBR and the inorganic filler can also be improved.

Description

Technical Field

[0001] This invention relates to the field of synthetic rubber technology, and more specifically, to a macromolecular bislithium initiator, its preparation method, and its application. Background Technology

[0002] Styrene-butadiene rubber (SBR), the earliest industrialized synthetic rubber with the largest production capacity, is a random copolymer of styrene and butadiene, primarily prepared through emulsion polymerization and solution polymerization. Solution-polymerized SBR, with its narrow molecular weight distribution, precise sequence distribution, and controllable microstructure, possesses excellent heat resistance, abrasion resistance, and aging resistance. Its processing performance and product performance are similar to natural rubber, and its vulcanization performance is superior. Therefore, it is widely used in vulcanized rubber products such as tires, modified plastics, and footwear materials.

[0003] As the global automotive industry accelerates its transformation towards green and low-carbon practices, more systematic technical requirements are being placed on tire performance. As the core material of tire tread compound, solution styrene-butadiene rubber (SSBR) needs to achieve breakthrough improvements in dynamic mechanical properties: Firstly, in terms of safety performance, the tread compound must possess excellent braking performance on wet and slippery roads, i.e., good anti-skid properties; secondly, in terms of energy conservation and emission reduction, it needs to minimize rolling resistance during driving; furthermore, based on environmental protection requirements, the tread compound must possess excellent wear resistance to reduce water pollution caused by tire wear debris.

[0004] However, in the process of preparing SSBR, existing initiators have problems such as poor oil solubility and easy deactivation of active centers, resulting in low initiation efficiency and the need for harsh low-temperature conditions, which seriously restricts the development of high-performance SSBR. Summary of the Invention

[0005] The purpose of this invention is to provide a macromolecular bislithium initiator, its preparation method, and its application. The prepared macromolecular bislithium initiator introduces long olefin chains, thereby significantly improving the oil solubility of the bislithium initiator, giving it higher stability and polymerization activity. Furthermore, amino functional groups are introduced onto the macromolecular bislithium initiator. The method for preparing SSBR using this macromolecular bislithium initiator can not only enhance the interfacial interaction between SSBR and carbon black or silica, but also improve the dispersion and mixing of SSBR with inorganic fillers.

[0006] To achieve the above objectives, the present invention provides a method for preparing a macromolecular bislithium initiator. Under an inert atmosphere, the preparation method includes the following steps: S100, reacting an amine monomer with an organolithium initiator in a solvent to obtain an amine-lithium initiator solution; S200, adding a conjugated olefin monomer to the amine-lithium initiator solution to react and obtain a macromolecular monolithium initiator solution; S300, adding a divinyl aromatic hydrocarbon to the macromolecular monolithium initiator solution to react and obtain a macromolecular bislithium initiator; wherein the divinyl aromatic hydrocarbon includes one of 1,3-diisopropenylbenzene and divinylbenzene.

[0007] The technical effects achieved by adopting this solution are as follows: First, an amine monomer reacts with an organolithium initiator to generate an amine lithium initiator. An amino functional group is then introduced into the amine lithium initiator. Next, an insertion-polymerization reaction occurs on the nitrogen-lithium bond of the amine lithium initiator via a conjugated olefin monomer, transforming the nitrogen-lithium active center into a more active and stable carbon-lithium active center, resulting in a macromolecular monolithium initiator with a long olefin chain. Finally, a nucleophilic addition reaction occurs on the two double bonds of a divinyl aromatic hydrocarbon to construct a dilithium active center, yielding a macromolecular dilithium initiator. The introduction of a long olefin chain into this macromolecular dilithium initiator significantly improves its oil solubility, stability, and polymerization activity. Furthermore, the introduction of an amino functional group into the macromolecular dilithium initiator allows for the preparation of SSBR using this method, which not only enhances the interfacial interaction between SSBR and carbon black or silica but also improves the dispersion and mixing of SSBR with inorganic fillers.

[0008] Furthermore, the amine monomer includes one of primary amines and secondary amines; and / or the organolithium initiator includes one of n-butyllithium, sec-butyllithium, and methyllithium; and / or the solvent includes one of tetrahydrofuran, diethyl ether, and cyclohexane; and / or the conjugated olefin includes one of butadiene, isoprene, isoprene, and 2,3-dimethyl-1,3-butadiene.

[0009] The technical effects achieved by adopting this technical solution are as follows: amine monomers serve as the source of the amino group in macromolecular dilithium initiators; by selecting primary and secondary amines, the reactivity and steric hindrance effect of the initiator can be precisely controlled. For organolithium initiators, n-butyllithium, sec-butyllithium, and methyllithium are selected; through precise matching of different alkyl structures, a synergistic effect can be formed with primary / secondary amine monomers. For solvents, tetrahydrofuran, diethyl ether, and cyclohexane are selected; through precise selection of solvents with different polarities, fine control of the polymerization process can be achieved. Conjugated olefins serve as the main chain segment of macromolecular dilithium initiators; their structural selection directly determines the performance characteristics of the initiator, significantly improving the oil solubility, stability, and polymerization activity of macromolecular dilithium initiators.

[0010] Further, the molar ratio of amine monomer, organolithium initiator and solvent is 1:1:(1~3); and / or the molar ratio of organolithium initiator to conjugated olefin monomer is 1:(200~1000); and / or the molar ratio of organolithium initiator to said divinyl aromatic hydrocarbon is 2:1.

[0011] The technical effects achieved by adopting this solution are as follows: Highly efficient preparation of macromolecular double-lithium initiators is achieved through precise control of the molar ratio of each component. The amine monomer, organolithium initiator, and solvent are mixed in a 1:1:(1~3) ratio, ensuring complete conversion of the amine lithiumization reaction and providing an optimal solvation environment to prevent initiator aggregation. A wide range of ratios (1:(200~1000)) between the organolithium initiator and conjugated olefin monomers allows for precise control of polyolefin segment lengths, meeting the molecular weight requirements of polymers in different applications. The 2:1 stoichiometric ratio of the organolithium initiator to divinyl aromatic hydrocarbons ensures complete reaction between each macromolecular single-lithium initiator and the divinyl aromatic hydrocarbon double bond, efficiently constructing the double-lithium active center. This multi-level precise ratio control system not only achieves designability of the initiator structure but also ensures the repeatability and stability of batch production, providing a reliable process foundation for the industrial-scale preparation of SSBRs with consistent performance.

[0012] Furthermore, the reaction temperature in step S100 is 0℃~30℃; and / or the reaction temperature in step S200 is 0℃~50℃; and / or the reaction temperature in step S300 is 0℃~50℃.

[0013] The technical effects achieved by adopting this solution are as follows: Efficient and controllable synthesis of macromolecular dilithium initiators is realized through staged temperature control. In step S100, a low-temperature reaction condition of 0℃~30℃ is used, ensuring efficient reaction between amine monomers and organolithium initiators while effectively suppressing the formation of byproducts. The wide temperature range of 0℃~50℃ in step S200 allows for flexible adjustment based on the reactivity of different conjugated olefin monomers. For example, polymerization of butadiene at higher temperatures (30℃~50℃) yields a higher 1,4-structure content, while polymerization of isoprene at lower temperatures (0℃~20℃) favors the formation of 3,4-structures. Step S300 maintains a reaction temperature of 0℃~50℃, ensuring efficient addition of divinyl aromatics to lithium-carbon active centers while avoiding deactivation of these centers. This gradient temperature control strategy not only achieves high conversion rates in each reaction step but also precisely controls the product structure through temperature adjustment, providing crucial process assurance for obtaining macromolecular dilithium initiators with customizable performance.

[0014] The present invention also provides a macromolecular bislithium initiator, which is prepared by the macromolecular bislithium initiator preparation method described above.

[0015] The technical effects achieved by adopting this technical solution are as follows: The introduction of long olefin chains into the macromolecular dilithium initiator significantly improves the oil solubility of the dilithium initiator, giving it higher stability and polymerization activity. Furthermore, the introduction of amino functional groups into the macromolecular dilithium initiator allows the method of preparing SSBR using this macromolecular dilithium initiator to not only enhance the interfacial interaction between SSBR and carbon black or silica, but also improve the dispersion and mixing of SSBR with inorganic fillers.

[0016] The present invention also provides a method for preparing dual-functionalized solution-polymerized styrene-butadiene rubber, which is prepared using the macromolecular bislithium initiator as described above.

[0017] The technical effects achieved by adopting this technical solution are as follows: This preparation method can not only enhance the interfacial interaction between SSBR and carbon black or silica, but also improve the dispersion and mixing of SSBR and inorganic fillers. The polar chain ends of SSBR can react with the surface of silica to form chemical bonds. At the same time, the interaction force between polar chain ends is enhanced, effectively reducing the number of free ends and restricting the random movement of free ends. This leads to the construction of a well-structured filler-polymer network, which significantly reduces the hysteresis loss of rubber materials.

[0018] Further, the preparation method of the dual-functionalized solution-polymerized styrene-butadiene rubber includes the following steps: S10, adding butadiene monomer, styrene monomer and structure regulator to a solvent, mixing evenly to obtain a monomer mixed solution; S20, adding an impurity-removing initiator to the monomer mixed solution to obtain a purified monomer mixed solution; S30, adding a macromolecular bis-lithium initiator to the purified monomer mixed solution to initiate a polymerization reaction to obtain an active dual-functionalized solution-polymerized styrene-butadiene rubber solution; S40, adding butadiene monomer to the active dual-functionalized solution-polymerized styrene-butadiene rubber to carry out an end-capping reaction to obtain a dual-functionalized solution-polymerized styrene-butadiene rubber solution with active butadiene segments at the ends; S50, adding a capping agent to the dual-functionalized solution-polymerized styrene-butadiene rubber solution with active butadiene segments at the ends to carry out a capping reaction to obtain a dual-functionalized solution-polymerized styrene-butadiene rubber solution; S60, adding an antioxidant to the dual-functionalized solution-polymerized styrene-butadiene rubber solution, removing the solvent, and drying to obtain a dual-functionalized solution-polymerized styrene-butadiene rubber.

[0019] The technical effects achieved by adopting this solution are as follows: This SSBR preparation method achieves controllable preparation of high-performance products through multi-step precise control. First, impurities in the system are effectively removed through impurity-removing initiator pretreatment, creating a pure reaction environment for the efficient action of the macromolecular bislithium initiator. Then, the macromolecular bislithium initiator is added to initiate the construction of a styrene-butadiene backbone structure. Next, butadiene is introduced at the end to form an active chain segment, so that the final product has both excellent mechanical properties and modifiability. Subsequently, the design of the end-capping reaction maintains the stability of the polymer chain and avoids the influence of the active end groups on subsequent processing. Finally, the addition of antioxidants and solvent removal ensure the storage stability of the product.

[0020] Furthermore, the structure modifier is tetrahydrofuran; and / or the decontamination initiator is n-butyllithium; and / or the end-capping agent includes one of propylene oxide and trimethoxychlorosilane.

[0021] The technical effects achieved by adopting this solution are as follows: By selecting tetrahydrofuran as a structure regulator, its strong polarity can effectively control the polymerization rate of styrene-butadiene, making the copolymer sequence distribution more uniform; by using n-butyllithium as a decontamination initiator, it can efficiently remove impurities (water, oxygen, etc.) from the system, and its residual activity can participate in subsequent polymerization reactions, avoiding the introduction of new impurity components; the end-capping agent is either propylene oxide or trimethoxychlorosilane. Propylene oxide achieves complete passivation of active end groups through a mild epoxy ring-opening reaction, while trimethoxychlorosilane can form stable Si-OC bonds, giving SSBR excellent hydrolysis resistance.

[0022] Furthermore, the total mass ratio of butadiene and styrene monomers to solvent is (0.11~0.25):1; the molar ratio of butadiene monomer to styrene monomer is (6~3):1; and / or the amount of structure modifier added is 200-1000 ppm of butadiene monomer mass; and / or the amount of impurity breaking initiator added is 5-10 ppm of solvent mass; and / or the molar ratio of end-capping agent to macromolecular bislithium initiator is (5~2):1.

[0023] The technical effects achieved by adopting this technical solution are as follows: By controlling the molar ratio of butadiene to styrene monomer within the range of (6~3):1, a reasonable ratio of flexible segments (polybutadiene) and rigid segments (polystyrene) in SSBR is ensured, giving the material both excellent elasticity and mechanical strength; by controlling the structure modifier, impurity initiator and end-capping agent, the activity and selectivity of the polymerization reaction are effectively controlled, and the occurrence of side reactions is reduced.

[0024] Furthermore, in step S10, the mixing temperature is 40℃~60℃; and / or in step S30, the polymerization temperature is 40℃~90℃ and the polymerization time is 30min~60min; and / or in step S40, the end-capping temperature is 60℃~90℃ and the end-capping reaction time is 5min~20min; and / or in step S50, the end-capping reaction time is 5min~20min.

[0025] The technical effects achieved by adopting this solution are as follows: In step S10, controlling the mixing temperature within the range of 40℃ to 60℃ ensures sufficient dissolution and mixing of the reactants while avoiding side reactions caused by excessively high temperatures; in step S30, the polymerization reaction uses a temperature range of 40℃ to 90℃ and a reaction time of 30 min to 60 min, which not only ensures the conversion rate of monomers but also effectively controls the molecular weight distribution; in step S40, the end-reaction temperature of 60℃ to 90℃ and the reaction time of 5 min to 20 min ensures the efficient conversion of end groups, providing active sites for subsequent functionalization; finally, in step S50, the end-capping reaction time of 5 min to 20 min ensures end-capping efficiency while avoiding over-reaction.

[0026] Compared with existing technologies, the following technical effects can be achieved: (1) Because the macromolecular double lithium initiator introduces a long olefin chain, it significantly improves the oil solubility and initiation efficiency of the double lithium initiator, giving it higher stability and polymerization activity; (2) Since the macromolecular double lithium initiator contains an amino functional group, the preparation method of SSBR using the macromolecular double lithium initiator improves the polarity of the SSBR molecular chain and the sulfurization reaction rate. (3) The dual-terminal functionalized SSBR prepared by this macromolecular double lithium initiator has a high molecular weight, narrow molecular weight distribution, high degree of functionalization, and the end group structure can be freely designed. Its dynamic performance of tire compound is significantly improved, and it has beneficial properties such as high wear resistance, high wet skid resistance, low rolling resistance and high strength. (4) The method of preparing SSBR using this macromolecular double lithium initiator can synthesize star-shaped SSBR in one step. This method avoids the addition of coupling agents with high equipment corrosion (such as silicon tetrachloride) and simplifies the operation steps. (5) The end-capping agent used is inexpensive, readily available, non-toxic, odorless, highly reactive, has a short reaction time, and has no side reactions. Attached Figure Description

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1This is a flowchart illustrating the steps of preparing the macromolecular double lithium initiator according to an embodiment of this application. Figure 2 This is a flowchart illustrating the steps of the method for preparing bifunctionalized solution-polymerized styrene-butadiene rubber according to an embodiment of this application. Figure 3 The reaction mechanism of the macromolecular dilithium initiator prepared in the embodiments of this application; Figure 4 The reaction mechanism of the active dual-terminal functionalized solution polymerized styrene-butadiene rubber prepared in the embodiments of this application; Figure 5 The end-capping reaction mechanism of the dual-functionalized solution-polymerized styrene-butadiene rubber prepared using propylene oxide as the end-capping agent in Example 1 of this application is described. Figure 6 This invention relates to the end-capping reaction mechanism of bifunctionalized solution-polymerized styrene-butadiene rubber prepared using trimethoxychlorosilane as the end-capping agent in Example 2 of this application. Detailed Implementation

[0028] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] This invention provides a method for preparing a macromolecular double lithium initiator. Under an inert atmosphere, the method includes the following steps: S100, reacting an amine monomer with an organolithium initiator in a solvent to obtain an amine-lithium initiator solution; S200, adding a conjugated olefin monomer to the amine-lithium initiator solution to react and obtain a macromolecular single lithium initiator solution; S300, adding a divinyl aromatic hydrocarbon to the macromolecular single lithium initiator solution to react and obtain a macromolecular double lithium initiator; wherein the divinyl aromatic hydrocarbon includes one of 1,3-diisopropenylbenzene and divinylbenzene. A flowchart of the preparation method for the macromolecular double lithium initiator in this embodiment is shown below. Figure 1 As shown.

[0030] This embodiment provides a method for preparing a macromolecular double lithium initiator. First, an amine monomer reacts with an organolithium initiator to generate an amine lithium initiator. An amino functional group is then introduced into the amine lithium initiator. Next, an insertion-polymerization reaction occurs on the nitrogen-lithium bond of the amine lithium initiator via a conjugated olefin monomer, transforming the nitrogen-lithium active center into a more active and stable carbon-lithium active center, resulting in a macromolecular single lithium initiator with a long olefin chain. Finally, a nucleophilic addition reaction occurs on the two double bonds of a divinyl aromatic hydrocarbon to construct a double lithium active center, yielding the macromolecular double lithium initiator. The introduction of a long olefin chain into this macromolecular double lithium initiator significantly improves its oil solubility, exhibits higher stability and polymerization activity, and the introduction of an amino functional group enhances the interfacial interaction between SSBR and carbon black or silica, while also improving the dispersion and mixing of SSBR with inorganic fillers.

[0031] In some embodiments of this application, the amine monomer includes one of primary amine and secondary amine; and / or the organolithium initiator includes one of n-butyllithium, sec-butyllithium, and methyllithium; and / or the solvent includes one of tetrahydrofuran, diethyl ether, and cyclohexane; and / or the conjugated olefin includes one of butadiene, isoprene, isoprene, and 2,3-dimethyl-1,3-butadiene.

[0032] In the preparation of a macromolecular double lithium initiator, amine monomers serve as the source of the amino group in the macromolecular double lithium initiator. The selection of primary and secondary amines allows for precise control of the initiator's reactivity and steric hindrance effect. For the organolithium initiator, n-butyllithium, sec-butyllithium, and methyllithium are selected. Through precise matching of different alkyl structures, a synergistic effect can be achieved with the primary / secondary amine monomers. For the solvent, tetrahydrofuran, diethyl ether, and cyclohexane are chosen. Precise selection of solvents with different polarities allows for fine control of the polymerization process. The conjugated olefin, as the main chain segment of the macromolecular double lithium initiator, has its structural selection directly determining the initiator's performance characteristics, significantly improving the oil solubility, stability, and polymerization activity of the macromolecular double lithium initiator.

[0033] The amine monomers selected are primary and secondary amines. Primary amines have higher reactivity and can react rapidly with organolithium reagents to form lithium amine initiators, making them suitable for polymerization systems requiring efficient initiation. Secondary amines, due to their more significant steric hindrance effect, can effectively suppress side reactions and improve the structural uniformity and stability of the initiator, making them particularly suitable for living polymerization systems requiring precise molecular weight control. Further amine monomers can be piperidine, pyrrole, tetrahydropyrrole, dimethylamine, cyclohexylimine, pyridine, piperazine, pyrazole, imidazole, etc.

[0034] The selected initiators for organolithium polymerization are n-butyllithium, sec-butyllithium, and methyllithium. Among them, n-butyllithium has moderate reactivity and good solubility, and can exist stably in solvents such as tetrahydrofuran, making it the preferred choice for industrial production. Due to the steric hindrance effect, sec-butyllithium exhibits higher reaction selectivity, which can reduce the occurrence of side reactions, making it particularly suitable for precision polymerization systems that require high-purity initiators. Methyllithium, on the other hand, has the strongest reactivity and can rapidly initiate polymerization reactions. For example, when n-butyllithium is combined with secondary amines (such as piperidine), the moderate reactivity and steric hindrance effect complement each other, ensuring the efficient progress of the amine lithiation reaction while suppressing side reactions. Due to its branched structure, sec-butyllithium can further improve the reaction selectivity when combined with amine monomers with large steric hindrance. The high reactivity of methyllithium is particularly suitable for use with primary amines with low steric hindrance (such as n-butylamine) to achieve rapid initiation.

[0035] The solvents selected are tetrahydrofuran, diethyl ether, and cyclohexane. Tetrahydrofuran, as a highly polar solvent, can effectively dissolve organolithium initiators and amine monomers, promoting the formation of a homogeneous reaction system, and is particularly suitable for polymerization systems requiring high reactivity. Diethyl ether has moderate polarity and a low boiling point, which facilitates low-temperature operation while maintaining good solubility, making it suitable for temperature-sensitive precision polymerization reactions. Cyclohexane, as a non-polar solvent, can effectively suppress the occurrence of side reactions.

[0036] The conjugated olefins are selected from butadiene, isoprene, isoprene, and 2,3-dimethyl-1,3-butadiene. Since the conjugated olefins are the core chain segments of macromolecular dilithium initiators, their structural selection directly determines the performance characteristics of the initiator. Butadiene can construct a polybutadiene backbone with excellent flexibility, ensuring good solubility and chain segment mobility of the initiator. Isoprene, through the introduction of methyl substituents, can improve thermal stability while maintaining chain segment flexibility. The special structure of isoprene can endow the initiator with unique stereoisomerism, enhancing compatibility with different monomers. And 2,3-dimethyl-1,3-butadiene, through the steric hindrance effect of the dimethyl group, significantly improves the structural stability and heat resistance of the initiator.

[0037] In some embodiments of this application, the molar ratio of amine monomer, organolithium initiator and solvent is 1:1:(1~3); and / or the molar ratio of organolithium initiator to conjugated olefin monomer is 1:(200~1000); and / or the molar ratio of organolithium initiator to divinyl aromatic hydrocarbon is 2:1.

[0038] In the preparation of a macromolecular double-lithium initiator, efficient preparation was achieved by precisely controlling the molar ratio of each component. The amine monomer, organolithium initiator, and solvent were mixed in a 1:1:(1~3) ratio, ensuring complete conversion of the amine lithiumization reaction and providing an optimal solvation environment to prevent initiator aggregation. A wide-range ratio of 1:(200~1000) between the organolithium initiator and the conjugated olefin monomer allowed for precise control of the polyolefin segment length, meeting the molecular weight requirements of polymers in different applications. The 2:1 stoichiometric ratio of the organolithium initiator to divinyl aromatic hydrocarbons ensured complete reaction of each macromolecular single-lithium initiator with the divinyl aromatic hydrocarbon double bond, efficiently constructing the double-lithium active center. This multi-stage precise ratio control system not only achieved designability of the initiator structure but also ensured the repeatability and stability of batch production, providing a reliable process foundation for the industrial-scale preparation of SSBRs with consistent performance.

[0039] In some embodiments of this application, the reaction temperature in step S100 is 0°C to 30°C; and / or the reaction temperature in step S200 is 0°C to 50°C; and / or the reaction temperature in step S300 is 0°C to 50°C.

[0040] In the preparation of a macromolecular dilithium initiator, efficient and controllable synthesis was achieved through staged temperature control. In step S100, a low-temperature reaction condition of 0℃~30℃ was used, ensuring efficient reaction between amine monomers and the organolithium initiator while effectively suppressing the formation of byproducts. The wider temperature range of 0℃~50℃ in step S200 allowed for flexible adjustment based on the reactivity of different conjugated olefin monomers. For example, polymerization of butadiene at higher temperatures (30℃~50℃) yielded a higher 1,4-structure content, while polymerization of isoprene at lower temperatures (0℃~20℃) favored the formation of 3,4-structures. Step S300 maintained a reaction temperature of 0℃~50℃ to ensure efficient addition of divinyl aromatics to the lithium carbon active center while avoiding deactivation of the active center. This gradient temperature control strategy not only achieved high conversion rates in each step but also precisely controlled the product structure through temperature regulation, providing crucial process assurance for obtaining macromolecular dilithium initiators with customizable performance.

[0041] An embodiment of the present invention also provides a macromolecular bislithium initiator, which is prepared by the preparation method described above.

[0042] This application proposes a macromolecular bislithium initiator by adopting the aforementioned preparation method. The macromolecular bislithium initiator introduces long olefin chains, thereby significantly improving the oil solubility of the bislithium initiator, giving it higher stability and polymerization activity. Furthermore, amino functional groups are introduced onto the macromolecular bislithium initiator. The method of preparing SSBR using this macromolecular bislithium initiator can not only enhance the interfacial interaction between SSBR and carbon black or silica, but also improve the dispersion and mixing of SSBR and inorganic fillers.

[0043] This application also provides a method for preparing dual-functionalized solution-polymerized styrene-butadiene rubber, which is prepared using the macromolecular bislithium initiator as described above.

[0044] This application describes a method for preparing SSBR using a macromolecular double lithium initiator. This method not only enhances the interfacial interaction between SSBR and carbon black or silica, but also improves the dispersion and mixing of SSBR and inorganic fillers. The polar chain ends of SSBR can react with the surface of silica to form chemical bonds, while the interaction between polar chain ends is enhanced, effectively reducing the number of free ends and restricting their random movement. This results in the construction of a well-structured filler-polymer network, significantly reducing the hysteresis loss of the rubber material.

[0045] In some embodiments of this application, a method for preparing dual-functionalized solution-polymerized styrene-butadiene rubber includes the following steps: S10, adding butadiene monomer, styrene monomer, and a structure modifier to a solvent and mixing them uniformly to obtain a monomer mixed solution; S20, adding an impurity-removing initiator to the monomer mixed solution to obtain a purified monomer mixed solution; S30, adding a macromolecular bis-lithium initiator to the purified monomer mixed solution to initiate a polymerization reaction to obtain an active dual-functionalized solution-polymerized styrene-butadiene rubber solution; S40, adding the active dual-functionalized solution-polymerized styrene-butadiene rubber to the solvent... Butadiene monomer is added to the rubber to carry out an end-reaction reaction, resulting in a bifunctionalized solution-polymerized styrene-butadiene rubber solution with active butadiene segments at the ends; S50, a capping agent is added to the bifunctionalized solution-polymerized styrene-butadiene rubber solution with active butadiene segments at the ends, and an end-capping reaction is carried out to obtain a bifunctionalized solution-polymerized styrene-butadiene rubber solution; S60, an antioxidant is added to the bifunctionalized solution-polymerized styrene-butadiene rubber solution, the solvent is removed, and after drying, bifunctionalized solution-polymerized styrene-butadiene rubber is obtained. The flowchart of the preparation method of the bifunctionalized solution-polymerized styrene-butadiene rubber in the example is shown below. Figure 2 As shown.

[0046] In the preparation of a dual-functionalized solution-polymerized styrene-butadiene rubber, firstly, impurities in the system are effectively removed through impurity-removing initiator pretreatment, creating a pure reaction environment for the efficient action of the macromolecular bis-lithium initiator. Then, the macromolecular bis-lithium initiator is added to initiate the construction of a styrene-butadiene backbone structure. Next, butadiene is introduced at the end to form an active chain segment, so that the final product has both excellent mechanical properties and modifiability. Subsequently, the design of the end-capping reaction maintains the stability of the polymer chain and avoids the influence of the active end groups on subsequent processing. Finally, the storage stability of the product is ensured by the addition of antioxidants and solvent removal.

[0047] In some embodiments of this application, the structure modifier is tetrahydrofuran; and / or the depurification initiator is n-butyllithium; and / or the end-capping agent includes one of propylene oxide and trimethoxychlorosilane.

[0048] In the preparation of a dual-functionalized solution-polymerized styrene-butadiene rubber (SSBR), tetrahydrofuran is selected as a structure regulator. Its strong polarity effectively controls the polymerization rate of styrene-butadiene, resulting in a more uniform copolymer sequence distribution. n-Butyllithium is used as a decontamination initiator, which efficiently removes impurities (water, oxygen, etc.) from the system, and its residual activity can participate in subsequent polymerization reactions, avoiding the introduction of new impurity components. The end-capping agent is either propylene oxide or trimethoxychlorosilane. Propylene oxide achieves complete passivation of the active end groups through a mild epoxy ring-opening reaction, while trimethoxychlorosilane forms stable Si-OC bonds, giving SSBR excellent hydrolysis resistance. Specifically, when the end-capping agent is propylene oxide, one end functional group of the dual-functionalized solution-polymerized styrene-butadiene rubber is a nitrogen-containing group, and the other end functional group is a hydroxyl group; when the end-capping agent is trimethoxychlorosilane, one end functional group of the end-functionalized solution-polymerized styrene-butadiene rubber is a nitrogen-containing group, and the other end functional group is a trimethoxysilyl group.

[0049] In some embodiments of this application, the mass ratio of the total mass of butadiene and styrene monomers to the solvent is (0.11~0.25):1; the molar ratio of butadiene monomer to styrene monomer is (6~3):1; and / or the amount of structure modifier added is 200-1000 ppm of the mass of butadiene monomer; and / or the amount of impurity-breaking initiator added is 5-10 ppm of the mass of solvent; and / or the molar ratio of end-capping agent to macromolecular bislithium initiator is (5~2):1.

[0050] In the preparation of a dual-functionalized solution-polymerized styrene-butadiene rubber (SSBR), by controlling the molar ratio of butadiene to styrene monomers within the range of (6~3):1, a reasonable ratio of flexible segments (polybutadiene) and rigid segments (polystyrene) in the SSBR is ensured, giving the material both excellent elasticity and mechanical strength. By controlling the structure modifier, impurity-breaking initiator, and end-capping agent, the activity and selectivity of the polymerization reaction are effectively controlled, reducing the occurrence of side reactions.

[0051] In some embodiments of this application, in step S10, the mixing temperature is 40°C to 60°C; and / or in step S30, the polymerization temperature is 40°C to 90°C and the polymerization time is 30 min to 60 min; and / or in step S40, the end-capping temperature is 60°C to 90°C and the end-capping reaction time is 5 min to 20 min; and / or in step S50, the end-capping reaction time is 5 min to 20 min.

[0052] In the preparation process of a dual-functionalized solution-polymerized styrene-butadiene rubber: In step S10, the mixing temperature is controlled within the range of 40℃ to 60℃, which ensures sufficient dissolution and mixing of the reactants while avoiding side reactions caused by excessively high temperatures; In step S30, the polymerization reaction is carried out at a temperature range of 40℃ to 90℃ and a reaction time of 30 min to 40 min, which not only ensures the conversion rate of monomers but also effectively controls the molecular weight distribution; In step S40, the end-capping reaction temperature of 60℃ to 90℃ and the reaction time of 5 min to 20 min ensure the efficient conversion of end groups, providing active sites for subsequent functionalization; Finally, in step S50, the end-capping reaction time of 5 min to 20 min ensures end-capping efficiency while avoiding over-reaction.

[0053] Example 1 Embodiments of the present invention provide a method for preparing bifunctionalized solution-polymerized styrene-butadiene rubber, comprising the following steps: S1. Under an inert atmosphere, 50 ml of piperidine, 100 ml of n-butyllithium, and 72 ml of tetrahydrofuran were added to a 3000 ml clean glass bottle to prepare an amine lithium initiator solution. The concentration of piperidine was 1 mol / L, the concentration of n-butyllithium was 0.5 mol / L, the concentration of tetrahydrofuran was 50 g / L, the molar ratio of piperidine, n-butyllithium, and tetrahydrofuran was 1:1:1, and the reaction temperature was 10 °C. S2. Under an inert atmosphere, 2175 ml of butadiene was added to the lithium amine initiator solution to allow the butadiene to undergo an insertion-polymerization reaction on the nitrogen-lithium bond of the lithium amine initiator, transforming the nitrogen-lithium active center into a more active and stable carbon-lithium active center, thus obtaining a piperidinyl polybutadiene macromolecular monolithium initiator solution, wherein the molar ratio of n-butyllithium to butadiene is 1:500, and the reaction temperature is 30℃. S3. Under an inert atmosphere, 50 ml of 1,3-diisopropenylbenzene was added to the piperidinyl polybutadiene macromolecular monolithium initiator solution to induce a nucleophilic addition reaction between the piperidinyl polybutadiene macromolecular monolithium initiator and the two double bonds of 1,3-diisopropenylbenzene, thereby preparing a 0.0204 mol / L macromolecular dilithium initiator solution, wherein the concentration of 1,3-diisopropenylbenzene was 0.5 mol / L, and the molar ratio of n-butyllithium to 1,3-diisopropenylbenzene was 1:0.5. The reaction temperature was 30℃. The reaction mechanism of the prepared macromolecular dilithium initiator is described in [reference needed]. Figure 3 As shown; S4. Add 5L of cyclohexane to a 10L anhydrous and oxygen-free reactor, then add 482g of butadiene monomer, 206g of styrene monomer and 11ml of tetrahydrofuran, heat to 50℃ and stir to mix evenly to obtain a monomer mixed solution. S5. Under stirring at 50℃, add 5 ml of n-butyllithium solution to the monomer mixture to eliminate polymerization impurities such as water and oxygen in the reaction system, and obtain a monomer mixture with impurities removed; wherein, the concentration of n-butyllithium is 0.5 mol / L; S6. Under stirring at 50℃, add 112.5 ml of macromolecular bislithium initiator solution to the impurity-free monomer mixture solution. The polymerization reaction temperature rises from 50℃ to 70℃ within 30 min. Then, add 8.7 ml of butadiene monomer and continue the reaction for 10 min to obtain a solution of bifunctionalized solution-polymerized styrene-butadiene rubber with active butadiene segments at the ends. The reaction mechanism of the prepared active bifunctionalized solution-polymerized styrene-butadiene rubber is described in [reference needed]. Figure 4 As shown; S8. Increase the stirring speed to twice that of step S6, add 14 ml of end-capping agent to the solution of bifunctionalized solution-polymerized styrene-butadiene rubber with active butadiene segments at the ends, and continue the end-capping reaction for 10 min to obtain a bifunctionalized solution-polymerized styrene-butadiene rubber solution. The concentration of the end-capping agent is 0.5 mol / L, and the end-capping agent is propylene oxide. The end-capping reaction mechanism is described in [link to relevant documentation]. Figure 5 As shown; S9. Discharge the dual-functionalized solution polymerized styrene-butadiene rubber solution from the bottom valve of the reactor into a 10-liter stainless steel drum, then add 22 ml of 100 g / L antioxidant solution, and then pour the dual-functionalized solution polymerized styrene-butadiene rubber solution into boiling water at 100℃ for wet coagulation. The cyclohexane solvent is vaporized and condensed for recovery, yielding 688 g of wet rubber. After cutting it into small pieces, spread it evenly on a stainless steel tray and place it in a vacuum oven at 70℃ for vacuum drying for 48 h to obtain dual-functionalized solution polymerized styrene-butadiene rubber.

[0054] Example 2 Embodiments of the present invention also provide a method for preparing bifunctionalized solution-polymerized styrene-butadiene rubber, comprising the following steps: S1. Under an inert atmosphere, 50 ml of piperidine, 100 ml of n-butyllithium, and 72 ml of tetrahydrofuran were added to a 3000 ml clean glass bottle to prepare an amine lithium initiator solution. The concentration of piperidine was 1 mol / L, the concentration of n-butyllithium was 0.5 mol / L, the concentration of tetrahydrofuran was 50 g / L, the molar ratio of piperidine, n-butyllithium, and tetrahydrofuran was 1:1:1, and the reaction temperature was 10 °C. S2. Under an inert atmosphere, 2175 ml of butadiene was added to the lithium amine initiator solution to allow the butadiene to undergo an insertion-polymerization reaction on the nitrogen-lithium bond of the lithium amine initiator, transforming the nitrogen-lithium active center into a more active and stable carbon-lithium active center, thus obtaining a piperidinyl polybutadiene macromolecular monolithium initiator solution, wherein the molar ratio of n-butyllithium to butadiene is 1:500, and the reaction temperature is 30℃. S3. Under an inert atmosphere, 50 ml of 1,3-diisopropenylbenzene was added to the piperidinyl polybutadiene macromolecular monolithium initiator solution to induce a nucleophilic addition reaction between the piperidinyl polybutadiene macromolecular monolithium initiator and the two double bonds of 1,3-diisopropenylbenzene, thereby preparing a 0.0204 mol / L macromolecular dilithium initiator solution, wherein the concentration of 1,3-diisopropenylbenzene was 0.5 mol / L, and the molar ratio of n-butyllithium to 1,3-diisopropenylbenzene was 1:0.5. The reaction temperature was 30℃. The reaction mechanism of the prepared macromolecular dilithium initiator is described in [reference needed]. Figure 3 As shown; S4. Add 5L of cyclohexane to a 10L anhydrous and oxygen-free reactor, then add 482g of butadiene monomer, 206g of styrene monomer and 11ml of tetrahydrofuran, heat to 50℃ and stir to mix evenly to obtain a monomer mixed solution. S5. Under stirring at 50℃, add 5 ml of n-butyllithium solution to the monomer mixture to eliminate polymerization impurities such as water and oxygen in the reaction system, and obtain a monomer mixture with impurities removed; wherein, the concentration of n-butyllithium is 0.5 mol / L; S6. Under stirring at 50℃, add 112.5 ml of macromolecular bislithium initiator solution to the impurity-free monomer mixture solution. The polymerization reaction temperature rises from 50℃ to 70℃ within 30 min. Then, add 8.7 ml of butadiene monomer and continue the reaction for 10 min to obtain a solution of bifunctionalized solution-polymerized styrene-butadiene rubber with active butadiene segments at the ends. The reaction mechanism of the prepared active bifunctionalized solution-polymerized styrene-butadiene rubber is described in [reference needed]. Figure 4 As shown; S8. Increase the stirring speed to twice that of step S6, add 14 ml of end-capping agent to the solution of bifunctionalized styrene-butadiene rubber with active butadiene segments at the ends, and continue the end-capping reaction for 10 min to obtain a bifunctionalized solution-polymerized styrene-butadiene rubber solution. The concentration of the end-capping agent is 0.5 mol / L, and the end-capping agent is trimethoxychlorosilane. The end-capping reaction mechanism is shown in [reference needed]. Figure 6 As shown; S9. Discharge the dual-functionalized solution polymerized styrene-butadiene rubber solution from the bottom valve of the reactor into a 10-liter stainless steel drum, then add 22 ml of 100 g / L antioxidant solution, and then pour the dual-functionalized solution polymerized styrene-butadiene rubber solution into boiling water at 100℃ for wet coagulation. The cyclohexane solvent is vaporized and condensed for recovery, yielding 688 g of wet rubber. After cutting it into small pieces, spread it evenly on a stainless steel tray and place it in a vacuum oven at 70℃ for vacuum drying for 48 h to obtain dual-functionalized solution polymerized styrene-butadiene rubber.

[0055] Comparative Example 1 Embodiments of the present invention also provide a method for preparing bifunctionalized solution-polymerized styrene-butadiene rubber, comprising the following steps: S1. Under an inert atmosphere, 50 ml of piperidine, 100 ml of n-butyllithium, and 72 ml of tetrahydrofuran were added to a 3000 ml clean glass bottle for reaction to prepare an amine lithium initiator solution. The concentration of piperidine was 1 mol / L, the concentration of n-butyllithium was 0.5 mol / L, the concentration of tetrahydrofuran was 50 g / L, the molar ratio of piperidine, n-butyllithium, and tetrahydrofuran was 1:1:1, and the reaction temperature was 10 °C. The concentration of the amine lithium initiator was 0.2252 mol / L. S2. Add 5L of cyclohexane to a 10L anhydrous and oxygen-free reactor, then add 482g of butadiene monomer, 206g of styrene monomer and 11ml of tetrahydrofuran, heat to 50℃ and stir to mix evenly to obtain a monomer mixed solution. S3. Under stirring at 50℃, add 5 ml of n-butyllithium solution to the monomer mixture to eliminate polymerization impurities such as water and oxygen in the reaction system, and obtain a purified monomer mixture; wherein, the concentration of n-butyllithium is 0.5 mol / L; S4. Under stirring at 50°C, add 10.2 ml of lithium amine initiator solution to the impurity-free monomer mixture solution. The polymerization reaction temperature rises from 50°C to 70°C within 30 min. Then add 8.7 ml of butadiene monomer and continue the reaction for 10 min to obtain a solution of double-terminal functionalized styrene-butadiene rubber with active butadiene segments at the ends. S5. Increase the stirring speed to twice that of step S6, add 14 ml of end-capping agent to the solution of double-ended functionalized styrene-butadiene rubber with active butadiene segments at the ends, and continue the end-capping reaction for 10 min to obtain a solution of double-ended functionalized styrene-butadiene rubber with an end-capping agent concentration of 0.5 mol / L. S6. Discharge the dual-functionalized solution-polymerized styrene-butadiene rubber solution from the bottom valve of the reactor into a 10-liter stainless steel drum, then add 22 ml of 100 g / L antioxidant solution, and then pour the dual-functionalized solution-polymerized styrene-butadiene rubber solution into boiling water at 100℃ for wet coagulation. The cyclohexane solvent is vaporized and condensed for recovery, yielding 688 g of wet rubber. After cutting it into small pieces, spread it evenly on a stainless steel tray and place it in a vacuum oven at 70℃ for vacuum drying for 48 h to obtain dual-functionalized solution-polymerized styrene-butadiene rubber.

[0056] Comparative Example 2 is solution-polymerized styrene-butadiene rubber (SBR) of Zhejiang Petrochemical Co., Ltd., model number 2564T; Comparative Example 3 is solution-polymerized SBR of Japan JSR Corporation, model number HPR 850.

[0057] The dry adhesive samples from Examples 1 and 2, and Comparative Examples 1, 2, and 3 were subjected to Mooney viscosity analysis at 100°C, GPC molecular weight analysis, infrared spectroscopy analysis, trace nitrogen element analysis, and DSC glass transition temperature analysis. Specific performance test results are shown in Table 1.

[0058] Table 1 Performance test results of Examples 1 and 2 and Comparative Examples 1, 2 and 3 This application also evaluates the compounding of the solution-polymerized styrene-butadiene rubber (SBR) of Examples 1 and 2, and compares its performance with that of Comparative Examples 1, 2, and 3. The compounding equipment used was a 1L internal mixer and a 6-inch hot and cold open mill from Xiamen Weibolun Technology Co., Ltd. The compounding process involved a two-stage process for the masterbatch and a one-stage process for the final compound. The compounding formulation of Example 1 is that of Example 3, the compounding formulation of Example 2 is that of Example 4, the compounding formulation of Comparative Example 1 is that of Comparative Example 4, the compounding formulation of Comparative Example 2 is that of Comparative Example 5, and the compounding formulation of Comparative Example 3 is that of Comparative Example 6. The compounding formulations of Examples 3 and 4 and Comparative Examples 4, 5, and 6 are shown in Table 2.

[0059] Table 2. Mixing formulations for Examples 3 and 4, and Comparative Examples 4, 5, and 6. To evaluate the performance differences between Examples 3 and 4 and Comparative Examples 4, 5, and 6, measurements were taken from four aspects: Payne effect, compression heat generation, wear resistance, and hysteresis performance.

[0060] Payne effect: Using RPA strain scanning mode, at 60℃ and 1Hz, the storage modulus (G') of the compound was observed to change abruptly around the strain amplitude of 0.1% and decrease sharply with increasing strain. The loss modulus (G'') reached its peak at the corresponding strain value, and G' no longer changed when the strain amplitude reached 15%.

[0061] Compression heat generation: Using the YS-25 compression fatigue testing machine of Shanghai Chemical Machinery Factory No. 4, in accordance with GB1687-1993 standard, the vulcanized rubber samples were tested for 25 minutes at an environment of 55℃, a load of 1.01MPa, a stroke of 4.45mm, and a frequency of 1800min⁻¹. The temperature difference before and after the test is taken as the dynamic compression fatigue temperature rise value. Preheating for 30 minutes is required before the test.

[0062] Abrasion resistance: Using a DIN abrasion tester and following national standards, vulcanized rubber samples of the test and benchmark samples were tested under the same load, abrasion stroke, and grinding wheel speed. The abrasion amount within the specified stroke was recorded to evaluate the difference in abrasion resistance.

[0063] Hysteresis performance: Using a dynamic mechanical analyzer (DMA), the dynamic mechanical properties of the vulcanized rubber samples are tested under a set temperature range and frequency. The focus is on analyzing the change curve of the loss factor (tanδ) with temperature or frequency. The larger the tanδ, the more significant the hysteresis performance.

[0064] These indicators and methods reveal the performance differences between the embodiments and comparative examples. The performance test results of embodiments 3 and 4 and comparative examples 4, 5 and 6 are shown in Table 3.

[0065] Table 3 Performance test results of Examples 3 and 4, and Comparative Examples 4, 5, and 6 A higher loss factor at 0°C indicates stronger wet grip performance, while a lower loss factor at 60°C indicates lower rolling resistance. Examples 3 and 4 show the highest loss factor at 0°C and the lowest at 60°C, indicating that tires made from bifunctionalized solution-polymerized styrene-butadiene rubber prepared using a macromolecular dilithium initiator exhibit the best safety and energy-saving performance. Comparative Example 6, also made from bifunctionalized solution-polymerized styrene-butadiene rubber, shows a certain degree of improvement in tire performance compared to Comparative Example 5, which is made from nonfunctionalized solution-polymerized styrene-butadiene rubber. Comparative Example 6 (HPR 850) has similar dynamic performance to Comparative Example 4, but is significantly inferior to the dynamic performance of Examples 3 and 4.

[0066] Since a higher abrasion index or lower abrasion amount indicates higher tire wear resistance, and considering the abrasion amount ranking as follows: Examples 3 and 4 < Comparative Example 4 ≈ Comparative Example 6 < Comparative Example 5, and the abrasion index ranking as follows: Comparative Example 5 < Comparative Example 4 ≈ Comparative Example 6 < Examples 3 and 4, it can be seen that the dual-functionalized solution-polymerized styrene-butadiene rubber prepared using a macromolecular dilithium initiator has excellent wear resistance. Among them, Comparative Example 6 and Comparative Example 4, prepared with a short-chain dilithium initiator, also showed improved tire wear resistance, while the rubber compound in Comparative Example 5 had the worst wear resistance.

[0067] The Payne effect mainly reflects the dispersibility of fillers in rubber materials; a lower Payne effect indicates a more uniform dispersion and mixing of fillers. The Payne effect results are as follows: Examples 3 and 4 < Comparative Example 6 < Comparative Example 4 < Comparative Example 5. The Payne effect results also show that the dual-functionalized solution-polymerized styrene-butadiene rubber prepared using a macromolecular bis-lithium initiator significantly improved the most uniform dispersion and mixing of rubber and silica. Comparative Example 6 and Comparative Example 4, prepared with a short-chain bis-lithium initiator, showed some improvement in silica dispersibility, but the degree of improvement was not as great as in Examples 3 and 4. This indicates that the dual-functionalized solution-polymerized styrene-butadiene rubber prepared with a short-chain bis-lithium initiator has a near-linear molecular structure, and its processing performance is not as good as that of the dual-functionalized solution-polymerized styrene-butadiene rubber prepared with a macromolecular bis-lithium initiator.

[0068] The temperature rise value obtained from the dynamic compression fatigue test directly reflects the tire's hysteresis, and the amount of internal heat reflects the tire's fatigue resistance, which is directly related to the tire's service life. It can be seen that the dual-end tubular solution-polymerized styrene-butadiene rubber prepared using a macromolecular dilithium initiator has the best fatigue resistance, followed by Comparative Example 6 and Comparative Example 4 prepared using a short-chain dilithium initiator, while Comparative Example 5 has the worst fatigue resistance.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for the preparation of a macromolecular dilithium initiator, characterized in that, The preparation method, under the protection of an inert atmosphere, includes the following steps: S100. React amine monomers with an organolithium initiator in a solvent to obtain an amine-lithium initiator solution; S200: Add a conjugated olefin monomer to the lithium amine initiator solution to react and obtain a macromolecular monolithium initiator solution; S300: Add divinyl aromatic hydrocarbon to the macromolecular monolithium initiator solution to react and obtain the macromolecular dilithium initiator; The divinyl aromatic hydrocarbon includes one of 1,3-diisopropenylbenzene and divinylbenzene.

2. The preparation method according to claim 1, characterized in that, The amine monomer includes one of primary amines and secondary amines; and / or The organolithium initiator includes one of n-butyllithium, sec-butyllithium, and methyllithium; and / or The solvent includes one of tetrahydrofuran, diethyl ether, and cyclohexane; and / or The conjugated olefin includes one of butadiene, isoprene, isoprene, and 2,3-dimethyl-1,3-butadiene.

3. The method of claim 1, wherein, The molar ratio of the amine monomer to the organolithium initiator is 1:1; and / or The molar ratio of the organolithium initiator to the conjugated olefin monomer is 1:(200~1000); and / or The molar ratio of the organolithium initiator to the divinyl aromatic hydrocarbon is 2:

1.

4. The method of claim 1, wherein, The reaction temperature in step S100 is 0℃~30℃; and / or The reaction temperature in step S200 is 0℃~50℃; and / or The reaction temperature in step S300 is 0℃~50℃.

5. A macromolecular bislithium initiator, wherein the macromolecular bislithium initiator is prepared by the preparation method according to any one of claims 1 to 4.

6. A method for preparing a dual-functionalized solution-polymerized styrene-butadiene rubber, wherein the dual-functionalized solution-polymerized styrene-butadiene rubber is prepared using the macromolecular bislithium initiator as described in claim 5.

7. The process for the preparation of a dual-end functional solution styrene-butadiene rubber according to claim 6, characterized in that, Includes the following steps: S10. Add butadiene monomer, styrene monomer and structure modifier to the solvent and mix them evenly to obtain a monomer mixed solution. S20. Add a decontamination initiator to the monomer mixture solution to obtain a monomer mixture solution with impurities removed; S30. Add the macromolecular double lithium initiator to the impurity-removed monomer mixed solution to initiate the polymerization reaction and obtain an active dual-terminal functionalized solution-polymerized styrene-butadiene rubber solution. S40. Add the butadiene monomer to the active dual-terminal functionalized solution-polymerized styrene-butadiene rubber to carry out the end reaction, and obtain a dual-terminal functionalized solution-polymerized styrene-butadiene rubber solution with active butadiene segments at the ends. S50. Add a capping agent to the solution of the dual-functionalized solution-polymerized styrene-butadiene rubber with active butadiene segments at the ends, and carry out a capping reaction to obtain a dual-functionalized solution-polymerized styrene-butadiene rubber solution. S60. Add an antioxidant to the solution of the dual-functionalized solution-polymerized styrene-butadiene rubber, remove the solvent, and dry to obtain dual-functionalized solution-polymerized styrene-butadiene rubber.

8. The method for preparing bifunctionalized solution-polymerized styrene-butadiene rubber according to claim 7, characterized in that, The structure modifier is tetrahydrofuran; and / or The impurity initiator is n-butyllithium; and / or The capping agent includes one of propylene oxide and trimethoxychlorosilane.

9. The process for the preparation of a dual-end functional solution styrene butadiene rubber according to claim 7, characterized in that, The mass ratio of the sum of the mass of the butadiene and the mass of the styrene monomer to the mass of the solvent is (0.11-0.25):1; the molar ratio of the butadiene monomer to the styrene monomer is (6-3):1; and / or The addition amount of the structure regulator is 200-1000 ppm of the mass of the butadiene monomer; and / or The addition amount of the impurity-removing initiator is 5-10 ppm of the mass of the solvent; and / or The molar ratio of the end-capping agent to the macro-lithium initiator is (5-2):

1.

10. The process for the preparation of a dual-end functional solution styrene butadiene rubber according to claim 7, characterized in that, In the S10 step, the mixing temperature is 40-60 DEG C; and / or In the S30 step, the temperature of the polymerization reaction is 40-90 DEG C, and the polymerization reaction time is 30-60 min; and / or In the S40 step, the temperature of the terminal reaction is 60-90 DEG C, and the reaction time of the terminal reaction is 5-20 min; and / or In the S50 step, the reaction time of the end-capping reaction is 5-20 min.

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