Double-end siloxane styrene-butadiene polymer, preparation method thereof, rubber composition and vulcanized rubber

Abstract

The invention provides a double-end siloxane styrene-butadiene polymer, a preparation method thereof, a rubber composition and vulcanized rubber. The preparation method comprises the following steps: reacting alkyl monolithium with dialkenyl benzene to obtain a dilithium initiator; adopting the dilithium initiator to initiate a polymerization reaction of butadiene and styrene; carrying out end capping by adopting binary anhydride; the preparation method comprises the following steps: reacting amino siloxane with a double-end carboxyl group functionalized polymer to obtain the double-end siloxane group styrene-butadiene polymer. The rubber composition provided by the invention comprises the double-end siloxane group styrene-butadiene polymer. The vulcanized rubber provided by the invention is prepared by mixing and vulcanizing the rubber composition. According to the method, the structure and molecular weight of the polymer are easy to control, so that the performance of the polymer is stable. The two ends of the polymer contain various functional groups, so that the dispersing performance of the filler in the polymer is improved, the strength and the wet skid resistance of vulcanized rubber are improved, and the rolling resistance is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber, and particularly relates to a double-terminal siloxane styrene-butadiene polymer and a preparation method thereof, a rubber composition and a vulcanized rubber. Background Art

[0002] New energy vehicles are developing rapidly and becoming more popular. New energy vehicles are heavy, quick to start, and have high requirements for driving range. This requires not only low rolling resistance and good wear resistance of tires, but also the need to increase tire load while reducing weight. This requires rubber materials to have higher modulus and ultra-low rolling resistance. However, the tires of traditional fuel vehicles currently do not meet the special performance requirements of new energy vehicle tires.

[0003] Solution polymerized styrene butadiene rubber (SSBR) is a butadiene-styrene random copolymer prepared by anionic polymerization of styrene and butadiene in hydrocarbon solvents using lithium alkane as an initiator. Compared with emulsion polymerized styrene butadiene rubber, solution polymerized styrene butadiene rubber can reduce the rolling resistance of tires by 20-30% and improve the anti-skid performance by 30-40%. In addition, SSBR adopts anionic polymerization method, the product structure is easy to adjust, and the brand is rich. SSBR is the most suitable basic material for new energy vehicle tires. At present, with the widespread application of silica filler, the weak interface between ordinary solution polymerized styrene butadiene rubber and silica causes poor dispersion of silica in the rubber matrix, which seriously affects the rubber performance and cannot meet the needs of new energy tires. Therefore, it is crucial to modify and upgrade solution polymerized styrene butadiene rubber, improve the dispersibility of silica in it, and enhance the performance of tire base rubber for the development of the new energy vehicle industry chain.

[0004] Functionalization is the most effective method to achieve high performance of SSBR, which mainly includes introducing polar groups such as nitrogen, hydroxyl, and silicon oxygen into the molecular chain to improve the dispersibility of white carbon black in the rubber matrix and inhibit the heat generated by the disordered movement of the polymer chain end, which can achieve the effect of improving the strength of the rubber, reducing its rolling resistance, and improving its anti-skid performance. At present, there are three main ways to functionalize solution-polymerized styrene butadiene rubber. The first is to use an initiator containing a functional group to initiate monomer polymerization to introduce functional groups into the starting end of the polymer chain. The second is to end-cap the polymer with a capping agent / coupling agent containing a functional group to introduce functional groups into the end of the polymer. The third is to introduce functional groups into the polymer chain by copolymerizing polar functional group monomers with butadiene and styrene. Chain-in functionalization is difficult to achieve large-scale application due to the small number of functionalized copolymer monomers and the high price. The chain-end functionalization method has received widespread attention in the industry in recent years due to its simple operation process. In particular, the double-end functionalized solution-polymerized styrene-butadiene rubber, because both the starting and the end of the molecular chain contain functional groups, has a high functional group content, which can further improve the dispersion of the filler in the rubber matrix, thereby improving the overall performance of the rubber. There are two main ways to prepare double-end functionalized solution-polymerized styrene-butadiene rubber. The first is to use a functionalized initiator to initiate, and a functionalized end-capping agent to end-cap, to prepare a solution-polymerized styrene-butadiene rubber containing different functional groups at both ends. The second is to use an initiator with dual active centers to initiate, and then use an end-capping agent to end-cap, to prepare a solution-polymerized styrene-butadiene rubber containing the same functional groups at both ends.

[0005] CN108864434A discloses a solution-polymerized styrene-butadiene rubber modified by epoxy polysiloxane, its preparation and application. The solution-polymerized styrene-butadiene rubber is a solution-polymerized styrene-butadiene rubber modified by epoxy polysiloxane chain segments, which is prepared by coupling the terminal active lithium of styrene-butadiene random copolymer with epoxy polysiloxane. The solution-polymerized styrene-butadiene rubber is applied to high-performance tire tread rubber and exhibits good affinity with white carbon black. Compared with general-purpose SSBR, the epoxy polysiloxane-modified SSBR not only has better grip traction, but also has a rolling resistance improvement rate of 23-28%.

[0006] CN113493535B discloses a siloxane-containing chain end functionalized polymer and its preparation method and application. The method uses a polar organic compound as a regulator and an organic lithium as an initiator in a hydrocarbon solvent to initiate a negative ion polymerization reaction of monovinyl aromatic hydrocarbons and / or conjugated dienes to generate an active polymer, and then the active polymer is first reacted with an epoxy capping agent to passivate the chain end activity, and then an end-capping reaction is carried out with a siloxane-containing end-capping agent to prepare a siloxane end-functionalized polymer. The siloxane end-functionalized polymer and the rubber composite material containing it have good interaction with carbon black and white carbon black, low rolling resistance and high anti-slip properties, and can be used in the tire industry.

[0007] CN107814878A discloses a bifunctionalized styrene butadiene polymer and a preparation method thereof. The general formula of the bifunctionalized styrene butadiene polymer is: (AmPR1)xSi(OR2)y(R3)z, wherein Am is an aromatic amine group, R1 and R2 are alkyl groups with 1 to 10 carbon atoms, R3 is an alkyl group or an aryl group with 1 to 10 carbon atoms, P is a styrene butadiene polymer, x=1 to 3, y=1 to 3, z=0 to 2, and x+y+z=4. The polymer is prepared by initiating polymerization of butadiene and styrene through the reaction of an amino compound with an organic lithium, and then adding a siloxane end-capping agent. The macromolecular chain of the bifunctionalized styrene butadiene polymer contains an aromatic amine group and a siloxane group at both ends, respectively.

[0008] CN102190757A discloses a method for synthesizing terminal functionalized star-shaped solution-polymerized styrene-butadiene rubber. The method uses multifunctional organic lithium as an initiator, Lewis base as a structure regulator and randomizer, and alkoxy lithium as a dissociating agent to initiate random copolymerization of butadiene and styrene, and after the polymerization reaction, adds terminal functionalizing agent tert-butyl diphenyl chlorosilane to carry out terminal functionalization reaction to obtain double-end modified solution-polymerized styrene-butadiene rubber. On the one hand, by using a multifunctional organic lithium initiator to initiate polymerization, the product is a full star structure without linear macromolecules; on the other hand, by functionalizing the end of the macromolecular chain with tert-butyl diphenyl chlorosilane, it not only plays a role in passivating the free end, but also improves the compatibility with carbon black. Compared with unmodified solution-polymerized styrene-butadiene rubber, the solution-polymerized styrene-butadiene rubber obtained by this method has low rolling resistance, high anti-slip properties and good physical and mechanical properties.

[0009] CN1578790A discloses a conjugated diene (co)polymerized rubber, a method for producing the (co)polymerized rubber, a rubber composition, a composite and a tire. The polymerized rubber is a conjugated diene (co)polymerized rubber having primary amino groups and alkoxysilyl groups bonded to the (co)polymer chain. The conjugated diene (co)polymerized rubber has good processability and is used to form a tire tread for automobiles, and can simultaneously have a balance of wear resistance, destructive characteristics, low hysteresis loss and anti-slip properties.

[0010] Studies have shown that siloxane is one of the best functional groups to improve the dispersibility of white carbon black. At present, the methods for siloxaneization of the ends of styrene butadiene polymers are mostly end-capped with halogenated siloxanes or siloxane reagents containing alkenyl groups that can react with the end of the active chain of styrene butadiene. However, this direct end-capping method has a side reaction of breaking the silicon-oxygen bond (Si-O), and the content of diploids and triploids in the polymer product is high, making the structure and molecular weight of siloxane-functionalized solution-polymerized styrene butadiene rubber difficult to control and the performance unstable. Moreover, the prior art usually uses a single lithium initiator to initiate the polymerization of butadiene and styrene, and uses a siloxane reagent to end-cap, which can only obtain styrene butadiene rubber containing a siloxane group at one end, and its functional group content is limited, so that the performance improvement of the polymer is limited. On the other hand, since the single lithium initiator is a single-end initiator, its initiation speed is slow, so the cost is high. Summary of the invention

[0011] In order to solve the above technical problems, the object of the present invention is to provide a double-terminal siloxane styrene-butadiene polymer and its preparation method, rubber composition and vulcanized rubber. The method of the present invention makes it easy to control the molecular weight of the prepared polymer and stabilize the performance of the polymer. The double-terminal of the polymer of the present invention contains functional groups such as siloxane, which can improve the dispersion performance of the filler in the polymer matrix.

[0012] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a dual-terminal siloxane-based styrene-butadiene polymer, which comprises the following steps:

[0013] (1) reacting a first hydrocarbon monolithium with a dienylbenzene to obtain a dilithium initiator;

[0014] (2) using the dilithium initiator to initiate an anionic polymerization reaction of butadiene and styrene in a solvent to obtain a system containing active chains of styrene-butadiene polymer;

[0015] (3) using a dibasic acid anhydride to end-cap the active chains of the styrene-butadiene polymer to obtain a system containing a dual-terminal carboxyl functionalized polymer;

[0016] (4) using aminosiloxane to react with the dual-terminal carboxyl functionalized polymer to obtain the dual-terminal siloxane-based styrene-butadiene polymer.

[0017] The preparation method of the present invention first uses dienylbenzene and hydrocarbon monolithium to react to prepare an initiator with dual active centers, then uses the initiator with dual active centers to initiate polymerization of butadiene and styrene, prepares a soluble polybutadiene molecular chain with a lithium active center at both ends, then uses a dibasic acid anhydride to perform dual-end carboxylation, and then uses an aminosiloxane functionalization reagent to react with the carboxyl group of the dual-end carboxyl functionalized polymer to finally prepare a dual-end siloxane styrene-butadiene polymer. The preparation method of the present invention avoids the problem that the structure and molecular weight of the polymer prepared by direct end-capping using a conventional siloxane functionalization reagent are difficult to control and the performance is unstable. At the same time, both ends of the molecular chain of the styrene-butadiene polymer prepared by the present invention contain siloxane functional groups. Relative to the SSBR containing siloxane functional groups at one end of the molecular chain, the dual-end siloxane functionalized SSBR of the present invention better improves the dispersibility of fillers such as white carbon black in the polymer matrix, so that the strength of the rubber is improved, the rolling resistance is reduced, and the anti-slip performance is improved, and the wear resistance, rolling resistance, and anti-slip performance (referred to as "devil's triangle") are better balanced. In addition, the method of the present invention uses a dilithium initiator for double-end initiation, which has a fast initiation speed, can reduce production costs and improve economic benefits.

[0018] In the above preparation method, preferably, the general formula of the first hydrocarbon monolithium is: R5Li, wherein R5 is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of two or more groups thereof containing 1 to 20 carbon atoms. More preferably, the first hydrocarbon monolithium includes one or a combination of n-butyllithium, sec-butyllithium, tert-butyllithium, phenylbutyllithium, naphthyllithium, cyclohexyllithium and dodecyllithium.

[0019] In the above preparation method, preferably, the dienylbenzene includes one or a combination of o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, o-diisopropenylbenzene, m-diisopropenylbenzene and p-diisopropenylbenzene.

[0020] In the above-mentioned preparation method, preferably, the reaction of the first hydrocarbon monolithium and the dienylbenzene is carried out in the presence of a polar compound and a hydrocarbon solvent, and the polar compound includes one or a combination of tetrahydrofuran, tetrahydrofurfuryl alcohol ethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetramethylethylenediamine, triethylamine and pentamethyldivinyltriamine.

[0021] In the above preparation method, preferably, the molar ratio of the dienylbenzene, the polar compound and the first hydrocarbon monolithium is 1:2-4:2-4.

[0022] In the above preparation method, preferably, in step (1), the reaction temperature of the first hydrocarbon monolithium and the dienylbenzene is -20°C to 60°C, and the reaction time is 1 to 6 hours. The reaction can be carried out under normal pressure.

[0023] In the above preparation method, preferably, based on the total weight of styrene and butadiene being 100%, the amount of styrene used is 10% to 50%, and the amount of butadiene used is 90% to 50%.

[0024] In the above preparation method, preferably, step (2) further comprises: adding a structure regulator and then performing the anionic polymerization reaction, wherein the structure regulator comprises one or a combination of tetrahydrofuran, tetrahydrofurfuryl alcohol ethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetramethylethylenediamine, triethylamine and pentamethyldivinyltriamine.

[0025] In the above preparation method, preferably, the molar ratio of the structure regulator to the first hydrocarbon monolithium is 0.8-10.0:1.

[0026] In the above preparation method, preferably, step (2) specifically comprises: adding the butadiene, the styrene, and the structure regulator to a solvent, adding an appropriate amount of a second hydrocarbon monolithium to react for 5 to 30 minutes when the temperature reaches 20°C to 40°C, then maintaining 20°C to 40°C or heating to 40°C to 60°C, adding the dilithium initiator obtained in step (1) to carry out anionic polymerization, and after the temperature rises to a point where it does not continue to rise (i.e., the highest temperature), continuing the reaction for 10 to 60 minutes to obtain a system containing active chains of styrene-butadiene polymers. The present invention does not impose any particular restrictions on the pressure of the anionic polymerization reaction in step (2), and it can be carried out under autogenous pressure, but if it exceeds the pressure range of the reactor, pressure relief is required.

[0027] In the above preparation method, in step (2), the purpose of adding the second hydrocarbon monolithium is mainly to remove impurities such as water in the polymerization system. The amount of the second hydrocarbon monolithium added in step (2) can be conventionally adjusted by a person skilled in the art, for example, the molar ratio of the second hydrocarbon monolithium to water in the polymerization system can be 1:1.

[0028] In the above preparation method, in step (2), the general formula of the second hydrocarbon monolithium is: R5Li, wherein R5 is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of two or more groups thereof containing 1 to 20 carbon atoms. More preferably, the second hydrocarbon monolithium includes one or a combination of n-butyllithium, sec-butyllithium, tert-butyllithium, phenylbutyllithium, naphthyllithium, cyclohexyllithium and dodecyllithium.

[0029] In the above preparation method, preferably, the dibasic acid anhydride includes one or a combination of maleic anhydride, succinic anhydride, methylsuccinic anhydride and phthalic anhydride.

[0030] In the above preparation method, preferably, the molar ratio of the dibasic acid anhydride to the first hydrocarbon monolithium is 1 to 6:1.

[0031] In the above preparation method, preferably, step (3) specifically comprises: adding ethylene oxide to the system containing the active chain of styrene-butadiene polymer obtained in step (2), reacting at 40°C to 130°C for 10 to 120 minutes, adding dibasic acid anhydride, reacting for another 10 to 120 minutes, and using a terminator to terminate the reaction to obtain a system containing a double-terminal carboxyl functionalized polymer. The present invention does not impose any particular restriction on the reaction pressure of step (3).

[0032] In the above preparation method, preferably, the molar ratio of the ethylene oxide to the first hydrocarbon monolithium is 1 to 6:1.

[0033] In the above preparation method, preferably, the general formula of the aminosiloxane is: Wherein, R1 is a hydrogen atom, a straight chain or branched alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, R2 is a straight chain or branched alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, R3 is a straight chain or branched alkyl group containing 1 to 10 carbon atoms, or a cycloalkyl group containing 3 to 10 carbon atoms, R4 is a straight chain or branched alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, x is 1 to 3, y is 0 to 2, and x+y=3. More preferably, the aminosiloxane includes one or a combination of 4-anilinotriethoxysilane, cyclohexylaminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (anilinomethyl)methyldimethoxysilane, [diethoxy(3-methylpent-3-yloxy)silyl]methylamine and 3-aminopropyldimethylmethoxysilane.

[0034] In the above preparation method, preferably, the molar ratio of the aminosiloxane to the first hydrocarbon monolithium is 1 to 5:1.

[0035] In the above preparation method, preferably, in step (4), the reaction temperature of the aminosiloxane and the dual-end carboxyl functionalized polymer is 40° C. to 130° C., and the reaction time is 10 to 120 min. The present invention does not impose any particular limitation on the reaction pressure of step (4).

[0036] The second aspect of the present invention provides a dual-terminal siloxane-based styrene-butadiene polymer, which is prepared by the above-mentioned preparation method of the dual-terminal siloxane-based styrene-butadiene polymer.

[0037] According to a specific embodiment of the present invention, preferably, the general formula of the dual-terminal siloxane styrene-butadiene polymer is:

[0038]

[0039] in, is a styrene-butadiene polymer chain, P is -CH=CH-, -CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)- or -C6H4-, R1 is a hydrogen atom, a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, R2 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, R3 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms or a cycloalkyl group containing 3 to 10 carbon atoms, R4 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, x is 1 to 3, y is 0 to 2, and x+y=3.

[0040] According to a specific embodiment of the present invention, preferably, the molecular weight of the dual-terminal siloxane-based styrene-butadiene polymer is 5,000 to 600,000.

[0041] The double-end siloxane styrene-butadiene polymer provided by the present invention contains nitrogen atoms, carbonyl groups, ester groups, siloxane groups and other functional groups at both ends. At least the nitrogen-containing group can interact with the functional groups on the surface of carbon black to promote the dispersion of fillers; at least the siloxane group can effectively improve the affinity of the polymer with white carbon black and promote the dispersion of white carbon black. The double-end siloxane styrene-butadiene polymer of the present invention can improve the dispersion performance of fillers therein.

[0042] The third aspect of the present invention provides a rubber composition, which includes: 100 parts by weight of the above-mentioned double-ended siloxane styrene-butadiene polymer, 30 to 70 parts by weight of a reinforcing agent, 0.5 to 3 parts by weight of a vulcanizing agent, 1 to 4 parts by weight of a vulcanization activator, 1 to 5 parts by weight of a vulcanization accelerator, 0.5 to 5 parts by weight of an antioxidant, 2 to 20 parts by weight of an extender oil, and 3.5 to 12 parts of a coupling agent.

[0043] A fourth aspect of the present invention provides a vulcanized rubber, which is prepared by mixing and vulcanizing the above-mentioned rubber composition.

[0044] The rubber composition and vulcanized rubber provided by the present invention overcome the defects of high rolling resistance and poor anti-skid performance of the vulcanized rubber obtained by conventional solution-polymerized styrene-butadiene rubber. In addition, compared with unfunctionalized or single-end functionalized solution-polymerized styrene-butadiene rubber, the mechanical properties of the vulcanized rubber of the present invention are enhanced, the rolling resistance is reduced, and the anti-skid performance is enhanced. Therefore, the present invention provides a high-performance energy-saving rubber with excellent comprehensive performance.

[0045] The technical solution of the present invention has at least the following beneficial effects:

[0046] 1. The present invention uses dienylbenzene and hydrocarbon monolithium to react to prepare a dilithium initiator with dual active centers, and then uses the dilithium initiator to initiate polymerization of styrene and butadiene. Due to the dual-end initiation, the reaction time is shortened, the cost is saved, and the economic benefit is improved.

[0047] 2. The method of the present invention carboxylates both ends of the polymer, and then reacts the carboxylated ends of the polymer with an aminosiloxane functionalizing agent, which greatly reduces the occurrence of the side reaction of Si-O bond breaking, or even prevents the side reaction from occurring, thereby reducing the generation of polyploids of the polymer chain, or even preventing the generation of polyploids of the polymer chain, making the structure and molecular weight of the polymer easy to control, thereby stabilizing its performance.

[0048] 3. The double-end styrene-butadiene polymer prepared by the method of the present invention contains functional groups. The double-end siloxane-based styrene-butadiene polymer of the present invention contains functional groups such as ester groups, carbonyl groups, siloxane groups, and amide groups. Due to the presence of multiple functional groups, the dispersion performance of fillers such as carbon black and white carbon black in the polymer matrix is ​​improved, and the occurrence of agglomeration is greatly reduced, thereby improving the strength and anti-slip performance of the vulcanized rubber finally obtained, reducing rolling resistance, and better balancing the "devil's triangle".

[0049] 4. The preparation method of the dual-terminal siloxane styrene-butadiene polymer of the present invention has a simple process and mild reaction conditions, can be carried out in a negative ion solution polymerization device in the prior art, and can be implemented on an industrial scale. DETAILED DESCRIPTION

[0050] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0051] According to a specific embodiment of the present invention, the first aspect of the present invention provides a method for preparing a dual-terminal siloxane-based styrene-butadiene polymer, which comprises the following steps:

[0052] (1) reacting a first hydrocarbon monolithium with a dienylbenzene to obtain a dilithium initiator;

[0053] (2) using the dilithium initiator to initiate an anionic polymerization reaction of butadiene and styrene in a solvent to obtain a system containing active chains of styrene-butadiene polymer;

[0054] (3) using a dibasic acid anhydride to end-cap the active chains of the styrene-butadiene polymer to obtain a system containing a dual-terminal carboxyl functionalized polymer;

[0055] (4) using aminosiloxane to react with the dual-terminal carboxyl functionalized polymer to obtain the dual-terminal siloxane-based styrene-butadiene polymer.

[0056] In some embodiments, the general formula of the first hydrocarbon monolithium is: R5Li, wherein R5 is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of two or more of them containing 1 to 20 carbon atoms. Preferably, the first hydrocarbon monolithium includes one or a combination of n-butyl lithium, sec-butyl lithium, tert-butyl lithium, phenylbutyl lithium, naphthyl lithium, cyclohexyl lithium and dodecyl lithium.

[0057] In some embodiments, the dienylbenzene includes one or a combination of o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, o-diisopropenylbenzene, m-diisopropenylbenzene and p-diisopropenylbenzene.

[0058] In some embodiments, the reaction of the first hydrocarbon monolithium with the dienylbenzene is carried out in the presence of a polar compound and a hydrocarbon solvent, wherein the polar compound comprises one or a combination of tetrahydrofuran, tetrahydrofurfuryl alcohol ethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetramethylethylenediamine, triethylamine and pentamethyldivinyltriamine, etc. The hydrocarbon solvent comprises, but is not limited to, one or a combination of benzene, toluene, ethylbenzene, xylene, pentane, hexane, heptane, octane, cyclopentane and cyclohexane, etc., and the amount thereof can be conventionally adjusted by a person skilled in the art.

[0059] In some embodiments, the molar ratio of the dienylbenzene, the polar compound, and the first hydrocarbon monolithium is 1:2-4:2-4.

[0060] In some embodiments, in step (1), the reaction temperature of the first hydrocarbon monolithium and the dienylbenzene is -20°C to 60°C, and the reaction time is 1 to 6 hours. The reaction can be carried out under normal pressure.

[0061] In some embodiments, the hydrocarbon monolithium, the dienylbenzene and the polar compound can be dissolved in hydrocarbon solvents respectively, and then the hydrocarbon monolithium solution, the dienylbenzene solution and the polar compound solution are used for reaction. The concentration of these solutions can be routinely adjusted by those skilled in the art. The hydrocarbon solvents used include, but are not limited to, one or a combination of pentane, hexane, heptane, octane, cyclopentane and cyclohexane.

[0062] In some embodiments, based on the total weight of styrene and butadiene being 100%, the amount of styrene used is 10% to 50%, and the amount of butadiene used is 90% to 50%.

[0063] It should be noted that the amount of initiator used corresponds to the molecular weight of the obtained polymer, and those skilled in the art can determine the ratio of the dilithium initiator to butadiene and styrene based on the molecular weight of the double-end siloxane styrene-butadiene polymer of the present invention. In some embodiments, step (2) further comprises: adding a structure regulator and then carrying out the anionic polymerization reaction, wherein the structure regulator comprises one or a combination of tetrahydrofuran, tetrahydrofurfuryl alcohol ethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetramethylethylenediamine, triethylamine and pentamethyldivinyltriamine, etc. In a preferred embodiment of the present invention, a polar organic compound is added to the polymerization reaction system as a structure regulator, which can adjust the vinyl content of butadiene, and can adjust the reactivity ratio of styrene and butadiene, so that styrene and butadiene are randomly copolymerized, and at the same time, the dilithium initiator can produce a polarization or solvation effect, reduce its degree of association, and increase the initiation reaction speed of a positive initiator such as n-butyllithium.

[0064] In some embodiments, the molar ratio of the structure regulator to the first hydrocarbon monolithium is 0.8 to 10.0:1.

[0065] In some embodiments, the structure regulator can be diluted with a hydrocarbon solvent to form a solution of the structure regulator with a volume concentration of 10% to 20%, and then added to the reaction system. The hydrocarbon solvent used includes but is not limited to pentane, hexane, heptane, octane, cyclopentane and cyclohexane, etc., or a combination of several thereof.

[0066] In some embodiments, step (2) specifically includes: adding the butadiene, the styrene, and the structure regulator to a solvent, adding an appropriate amount of a second hydrocarbon monolithium to react for 5 to 30 minutes when the temperature reaches 20°C to 40°C, then maintaining 20°C to 40°C or heating to 40°C to 60°C, adding the dilithium initiator obtained in step (1) to carry out anionic polymerization, and after the temperature rises to a temperature that does not continue to rise (i.e., the highest temperature), continuing the reaction for 10 to 60 minutes to obtain a system containing active chains of styrene-butadiene polymers. The present invention does not impose any particular restrictions on the pressure of the anionic polymerization reaction in step (2), and it can be carried out under autogenous pressure, but if it exceeds the pressure range of the reactor, pressure relief is required.

[0067] In some embodiments, in step (2), the solvent used for the anionic polymerization reaction of the butadiene and the styrene in the solvent includes a hydrocarbon solvent, specifically, one or a combination of benzene, toluene, ethylbenzene, xylene, pentane, hexane, heptane, octane, cyclopentane and cyclohexane. The total amount of the butadiene and the styrene in the hydrocarbon solvent may have a concentration of 5% to 20% (mass concentration).

[0068] In some embodiments, in step (2), the purpose of adding the second hydrocarbon monolithium is mainly to remove impurities such as water in the polymerization system. Preferably, the molar ratio of the amount of the second hydrocarbon monolithium added in step (2) to the water in the polymerization system can be 1:1.

[0069] In some embodiments, in step (2), the general formula of the second hydrocarbon monolithium is: R5Li, wherein R5 is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of two or more groups thereof containing 1 to 20 carbon atoms. More preferably, the second hydrocarbon monolithium includes one or a combination of n-butyl lithium, sec-butyl lithium, tert-butyl lithium, phenylbutyl lithium, naphthyl lithium, cyclohexyl lithium and dodecyl lithium. The second hydrocarbon monolithium may be the same as or different from the first hydrocarbon monolithium in step (1). The second hydrocarbon monolithium may be dissolved in a hydrocarbon solvent and then added. The hydrocarbon solvent includes but is not limited to one or a combination of pentane, hexane, heptane, octane, cyclopentane and cyclohexane, and the concentration thereof may be conventionally adjusted by a person skilled in the art.

[0070] In some embodiments, the dibasic acid anhydride includes one or a combination of maleic anhydride, succinic anhydride, methylsuccinic anhydride, phthalic anhydride, etc. Preferably, the dibasic acid anhydride is succinic anhydride.

[0071] In some embodiments, the molar ratio of the dibasic acid anhydride to the first hydrocarbon monolithium is 1 to 6:1.

[0072] In some embodiments, step (3) specifically comprises: adding ethylene oxide to the system containing the active chain of styrene-butadiene polymer obtained in step (2), reacting at 40° C. to 130° C. for 10 to 120 minutes, adding dibasic acid anhydride, reacting for another 10 to 120 minutes, and then using a terminator to terminate the reaction to obtain a system containing a double-terminal carboxyl functionalized polymer. The present invention does not impose any particular limitation on the reaction pressure of step (3).

[0073] In some embodiments, the molar ratio of the ethylene oxide to the first hydrocarbon monolithium is 1 to 6:1.

[0074] In some embodiments, the added ethylene oxide is added in the form of a tetrahydrofuran solution of ethylene oxide. The added dibasic acid anhydride is added in the form of a tetrahydrofuran solution of dibasic acid anhydride. The concentrations of the tetrahydrofuran solution of ethylene oxide and the tetrahydrofuran solution of dibasic acid anhydride can be routinely adjusted by those skilled in the art.

[0075] In some embodiments, the terminator includes an alcoholic acid solution. The acid includes one or a combination of hydrochloric acid, sulfuric acid and nitric acid. The alcohol includes one or a combination of methanol, ethanol and butanol. The molar ratio of the acid to the hydrocarbon monolithium is 0.8 to 10:1. The concentration of the acid in the alcoholic acid solution can be routinely adjusted by a person skilled in the art.

[0076] In some embodiments, the aminosiloxane has the general formula: Wherein, R1 is a hydrogen atom, a straight chain or branched alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, R2 is a straight chain or branched alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, R3 is a straight chain or branched alkyl group containing 1 to 10 carbon atoms, or a cycloalkyl group containing 3 to 10 carbon atoms, R4 is a straight chain or branched alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, x is 1 to 3, y is 0 to 2, and x+y=3. Preferably, the aminosiloxane includes one or a combination of 4-anilinotriethoxysilane, cyclohexylaminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (anilinomethyl)methyldimethoxysilane, [diethoxy(3-methylpent-3-yloxy)silyl]methylamine and 3-aminopropyldimethylmethoxysilane.

[0077] In some embodiments, the molar ratio of the aminosiloxane to the first hydrocarbon monolithium is 1 to 5:1.

[0078] In some embodiments, in step (4), the reaction temperature of the aminosiloxane and the dual-terminal carboxyl functionalized polymer is 40° C. to 130° C., and the reaction time is 10 to 120 min. The present invention does not impose any particular limitation on the reaction pressure of step (4).

[0079] In some embodiments, the preparation method of the double-terminal multi-functionalized butadiene styrene polymer specifically comprises the following steps:

[0080] (1) Preparation of dilithium initiator

[0081] A protective gas (such as nitrogen) is passed through the reactor for replacement 3 to 5 times, and then a first hydrocarbon solvent is added to the reactor, and then a solution of dienylbenzene and a solution of a polar compound are added, and then a solution of a first hydrocarbon monolithium is slowly added under stirring at -20°C to 60°C, and the reaction is carried out for 1 to 6 hours to obtain a dilithium initiator;

[0082] (2) Preparation of styrene-butadiene polymer active chains

[0083] Pass a protective gas (such as nitrogen) into the reactor for replacement 3 to 5 times, then add a second hydrocarbon solvent, butadiene, styrene, and a solution of a structure regulator with a volume concentration of 10 to 20% into the reactor, start stirring and heating, and stop heating when the temperature in the reactor reaches 20° C. to 40° C., add an appropriate amount of a second hydrocarbon monolithium solution and react for 5 to 30 minutes to remove impurities in the polymerization system, then maintain 20° C. to 40° C. or raise the temperature to 40° C. to 60° C., add the dilithium initiator obtained in step (1) to carry out anionic polymerization, and after the temperature rises to a temperature that stops rising (i.e., the highest temperature), continue the reaction for 10 to 60 minutes to obtain a system containing active chains of styrene-butadiene polymers;

[0084] The first hydrocarbon solvent and the second hydrocarbon solvent include, but are not limited to, one or a combination of benzene, toluene, ethylbenzene, xylene, pentane, hexane, heptane, octane, cyclopentane and cyclohexane;

[0085] The solvents in the dienylbenzene solution, the polar compound solution, the first hydrocarbon monolithium solution, and the second hydrocarbon monolithium solution include, but are not limited to, one or a combination of pentane, hexane, heptane, octane, cyclopentane, and cyclohexane;

[0086] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0087] Adding a tetrahydrofuran solution of ethylene oxide to the system containing active chains of styrene-butadiene polymer obtained in step (2), maintaining the temperature in the reactor at 40° C. to 130° C., reacting for 10 to 120 minutes, adding a tetrahydrofuran solution of dibasic acid anhydride, reacting for 10 to 120 minutes, and terminating the reaction with a terminator to obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0088] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0089] Add aminosiloxane to the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 40°C to 130°C, react for 10 to 120 minutes, discharge the material, and obtain a double-terminal siloxane-based styrene-butadiene polymer after rotary evaporation and drying.

[0090] In some specific embodiments, taking m-diolefin benzene as an example, the reaction process of steps (1) to (4) of the above preparation method is as follows:

[0091]

[0092]

[0093] in, The invention relates to a styrene-butadiene polymer chain, wherein P is -CH=CH-, -CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)- or -C6H4-, R is a hydrogen atom or a methyl group, R' is an alkyl group or an aryl group, R1 is a hydrogen atom, a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, and R2 is a cycloalkyl group containing 1 to 10 carbon atoms. R is a straight-chain or branched-chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, R3 is a straight-chain or branched-chain alkyl group containing 1 to 10 carbon atoms, or a cycloalkyl group containing 3 to 10 carbon atoms, R4 is a straight-chain or branched-chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms, x is 1 to 3, y is 0 to 2, and x+y=3.

[0094] According to a specific embodiment of the present invention, a second aspect of the present invention provides a dual-terminal siloxane-based styrene-butadiene polymer, which is prepared by the above-mentioned preparation method of the dual-terminal siloxane-based styrene-butadiene polymer.

[0095] According to a specific embodiment of the present invention, preferably, the general formula of the dual-terminal siloxane styrene-butadiene polymer is:

[0096]

[0097] in, is a styrene-butadiene polymer chain, P is -CH=CH-, -CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)- or -C6H4-, R1 is a hydrogen atom, a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, R2 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, R3 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms or a cycloalkyl group containing 3 to 10 carbon atoms, R4 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, x is 1 to 3, y is 0 to 2, and x+y=3.

[0098] According to a specific embodiment of the present invention, preferably, the molecular weight of the dual-terminal siloxane-based styrene-butadiene polymer is 5,000 to 600,000.

[0099] According to a specific embodiment of the present invention, the third aspect of the present invention provides a rubber composition, which includes: 100 parts by weight of the above-mentioned double-ended siloxane styrene-butadiene polymer, 30 to 70 parts by weight of a reinforcing agent, 0.5 to 3 parts by weight of a vulcanizing agent, 1 to 4 parts by weight of a vulcanization activator, 1 to 5 parts by weight of a vulcanization accelerator, 0.5 to 5 parts by weight of an antioxidant, 2 to 20 parts by weight of an extender oil, and 3.5 to 12 parts of a coupling agent.

[0100] In the above-mentioned rubber composition, the reinforcing agent, the vulcanizing agent, the vulcanization activator, the vulcanization accelerator, the antioxidant, the filling oil and the coupling agent may all be additives in the rubber composite material in the prior art.

[0101] In some embodiments, the reinforcing agent includes carbon black and / or white carbon black, etc.

[0102] In some embodiments, the sulfurizing agent includes sulfur or other sulfur-containing compounds.

[0103] In some embodiments, the vulcanization activator includes zinc oxide and / or stearic acid.

[0104] In some embodiments, the vulcanization accelerator includes one or a combination of accelerator TBBS, accelerator DM, accelerator D, accelerator NS, and the like.

[0105] In some embodiments, the antioxidant includes antioxidant 4021A and the like.

[0106] In some embodiments, the filler oil includes one or a combination of A1820, A1426, N4010, N4016, etc.

[0107] In some embodiments, the coupling agent includes one or a combination of γ-aminopropyltriethoxysilane (KH550), γ-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH560), γ-methacryloxypropyltrimethoxysilane (KH570), γ-mercaptopropyltriethoxysilane (KH580), γ-mercaptopropyltrimethoxysilane (KH590), bis(γ-triethoxysilylpropyl)-tetrasulfide (Si69), etc.

[0108] A fourth aspect of the present invention provides a vulcanized rubber, which is prepared by mixing and vulcanizing the above-mentioned rubber composition.

[0109] In the present invention, the mixing method and conditions can adopt conventional techniques in the art. The mixing can be carried out in a conventional mixer. The mixing of the various substances can be carried out simultaneously or in steps. The vulcanization can be carried out in a vulcanizing bed or a flat vulcanizing machine. The method and conditions for vulcanizing the mixed rubber can be conventional techniques in the art. For example, the conditions of the vulcanization reaction include: the vulcanization temperature can be 120°C to 150°C, the vulcanization pressure can be 10 to 15MPa, and the vulcanization time can be 10 to 30min.

[0110] The technical scheme of the present invention is specifically described below through examples and comparative examples, but the present invention is not limited to these examples and can of course be implemented in various modifications within the scope of the gist of the present invention.

[0111] The raw materials used in the embodiments and comparative examples include:

[0112] Styrene: polymerization grade, mass fraction not less than 99.8%, water content not more than 20μg / g, synthetic rubber plant of Lanzhou Petrochemical Company of PetroChina;

[0113] Butadiene: polymerization grade, synthetic rubber plant of PetroChina Lanzhou Petrochemical Company;

[0114] Cyclopentane: industrial grade, synthetic rubber plant of PetroChina Lanzhou Petrochemical Company;

[0115] n-Butyl lithium solution: 1.6 mol / L (n-hexane as solvent);

[0116] Sec-butyl lithium solution: 1.3 mol / L (n-hexane as solvent);

[0117] Tert-butyl lithium solution: 1.7 mol / L (cyclopentane as solvent);

[0118] Ethylene oxide tetrahydrofuran solution: 3 mol / L;

[0119] Succinic anhydride: ≥99%, San Chemical Technology (Shanghai) Co., Ltd.

[0120] Maleic anhydride: ≥99.5%, Xilong Chemical Co., Ltd.

[0121] Methylsuccinic anhydride: 98%, Sinopharm Chemical Reagent Co., Ltd.;

[0122] Phthalic anhydride: 99%, Sinopharm Chemical Reagent Co., Ltd.

[0123] 4-anilinotriethoxysilane: Beijing Huawei Ruike Chemical Co., Ltd.;

[0124] Cyclohexylaminopropyltrimethoxysilane: Hubei Jusheng Technology Co., Ltd.;

[0125] [Diethoxy(3-methylpent-3-yloxy)silyl]methylamine: Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0126] (Anilinemethyl)methyldimethoxysilane: Shanghai Aladdin Biochemical Technology Co., Ltd.

[0127] 3-Aminopropyldimethylmethoxysilane: Shanghai Aladdin Biochemical Technology Co., Ltd.

[0128] 3-Aminopropyltriethoxysilane: Sinopharm Chemical Reagent Co., Ltd.

[0129] Tetrahydrofurfuryl alcohol ethyl ether (ETE): analytical grade, obtained from PetroChina Dushanzi Petrochemical Company;

[0130] Other reagents not listed are also commercially available products.

[0131] The analysis and testing methods used in the embodiments and comparative examples include:

[0132] Molecular weight and molecular weight distribution: Waters 2414 gel permeation chromatograph (GPC) was used to measure the weight average molecular weight (Mw) and number average molecular weight (Mn), and the molecular weight distribution (Mw / Mn) was calculated. The calibration curve was prepared with polystyrene standards, the mobile phase was tetrahydrofuran, the column temperature was 40°C, the sample concentration was 1 mg / mL, the injection volume was 50 μL, the elution time was 40 min, and the flow rate was 1 ml min -1 .

[0133] 1 H NMR analysis: The analysis was performed using a Bruker 400 MHz nuclear magnetic resonance (NMR) spectrometer, AVANCE NEO 400M, and the solvent was deuterated chloroform.

[0134] Tensile strength: tested according to the method described in GB / T528-2009.

[0135] Mooney viscosity: M200 E Mooney viscometer was used to test according to the method described in GB / T1232.1-2000, using a large rotor, preheating for 1 min, testing for 4 min, and the test temperature was 100°C.

[0136] Shore A hardness: Use LX-A rubber hardness tester and test according to the method described in GB / T 6031-2017.

[0137] Rolling resistance and wet skid resistance: The test was conducted in accordance with the method described in ASTM D7028-2007, using a tensile mode with a pre-strain of 7%, a dynamic strain of 6.75% to 7.25%, a loading frequency of 10 Hz, a temperature scan range of -90 to 80°C, a heating rate of 2°C / min, and rolling resistance was determined based on tanδ at 60°C, and wet skid resistance was determined based on tanδ at 0°C.

[0138] Akron wear volume: tested according to the method described in GB / T 1689-2014. The lower the value, the better the wear resistance of the material.

[0139] Example 1

[0140] (1) Preparation of dilithium initiator

[0141] First, nitrogen was passed into a 100 mL flask for replacement 5 times, and then 30 mL of cyclopentane was added as a solvent, and then 1 mL of a cyclopentane solution of 1,3-diisopropenylbenzene (volume concentration 10%) and 1.67 mL of a cyclopentane solution of triethylamine (volume concentration 10%) were added in sequence, and 0.75 mL of an n-butyl lithium solution (1.6 mol / L) was slowly added at -15°C with stirring, and the reaction was continued for 3 hours to obtain a dilithium initiator;

[0142] (2) Preparation of styrene-butadiene polymer active chains

[0143] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three times, and then 1.2kg of cyclohexane, 144g of butadiene, 36g of styrene, and 3.3mL of a cyclopentane solution of tetrahydrofurfuryl alcohol ethyl ether (volume concentration 20%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 40°C, 0.25mL of n-butyl lithium solution (1.6mol / L) was added and reacted for 10min to remove impurities in the system, and then the temperature was continuously raised to 45°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 30min to obtain a system containing active chains of styrene-butadiene polymer;

[0144] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0145] Add 1.35 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 60° C., react for 40 min, add 4.05 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, react for 40 min, add 5 mL of a 1 mol / L ethanol solution of hydrochloric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0146] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0147] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), 0.78 mL of cyclohexylaminopropyltrimethoxysilane was added, the temperature in the reactor was maintained at 85° C., and the material was discharged after reacting for 65 minutes. After rotary evaporation and drying, a double-terminal siloxane-based styrene-butadiene polymer P-1 was obtained.

[0148] GPC measured the number average molecular weight of the polymer P-1 to be 149,200 and the molecular weight distribution to be 1.10. 1 The mass percentage of styrene units in the polymer P-1 measured by H-NMR was 20.1%.

[0149] Comparative Example 1

[0150] First, nitrogen was passed into a 3L stainless steel reactor with a jacket for replacement three times, and then 1.2kg of cyclohexane, 144g of butadiene, 36g of styrene, and 3.3mL of a cyclopentane solution of tetrahydrofurfuryl alcohol ethyl ether (volume concentration 20%) were added into the reactor. Stirring and heating were started. When the temperature in the reactor reached 40°C, heating was stopped. 1mL of n-butyl lithium solution (1.6mol / L) was added. After the temperature rose to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 30min. An excess of anhydrous ethanol was added to terminate the reaction to obtain an unfunctionalized styrene-butadiene polymer D-1.

[0151] GPC measured the number average molecular weight of the polymer D-1 to be 148,200 and the molecular weight distribution to be 1.17. 1 The mass percentage of styrene units in the polymer D-1 measured by H-NMR was 20.1%.

[0152] Example 2

[0153] (1) Preparation of dilithium initiator

[0154] First, nitrogen was passed into a 100 mL flask for replacement three times, and then 30 mL of cyclopentane was added as a solvent, and then 0.62 mL of a cyclopentane solution of 1,3-diisopropenylbenzene (volume concentration 10%) and 1.25 mL of a cyclopentane solution of triethylamine (volume concentration 10%) were added in sequence, and 0.56 mL of an n-butyl lithium solution (1.6 mol / L) was slowly added at -15°C with stirring, and after reacting for 3 hours, a dilithium initiator was obtained;

[0155] (2) Preparation of styrene-butadiene polymer active chains

[0156] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement 5 times, and then 1.1kg of cyclohexane, 126g of butadiene, 54g of styrene, and 1.87mL of a cyclopentane solution of diethylene glycol dimethyl ether (volume concentration 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 25°C, 0.25mL of n-butyl lithium solution (1.6mol / L) was added and reacted for 5min to eliminate impurities in the system, and then the temperature was continuously raised to 40°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 10min to obtain a system containing active chains of styrene-butadiene polymer;

[0157] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0158] Add 0.78 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 70° C., react for 30 min, add 3.2 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, react for 30 min, add 3.2 mL of a 1 mol / L ethanol solution of hydrochloric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0159] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0160] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), 0.85 mL of cyclohexylaminopropyltrimethoxysilane was added, the temperature in the reactor was maintained at 80° C., and the material was discharged after reacting for 60 minutes. After rotary evaporation and drying, a double-terminal siloxane-based styrene-butadiene polymer P-2 was obtained.

[0161] GPC measured the number average molecular weight of the polymer P-2 to be 210,000 and the molecular weight distribution to be 1.10. 1 The mass percentage of styrene units in the polymer P-2 measured by H-NMR was 29.8%.

[0162] Comparative Example 2

[0163] The difference from Example 2 is that: steps (1) and (3) are not performed, in step (2), the initiator is replaced with 0.91 mL of n-butyl lithium solution (1.6 mol / L), and after completing step (2), 0.85 mL of cyclohexylaminopropyltrimethoxysilane is directly added, the temperature in the reactor is maintained at 80° C., and after reacting for 60 minutes, an excess of anhydrous ethanol is added to terminate the reaction, thereby obtaining a single-end siloxane-based styrene-butadiene polymer D-2.

[0164] GPC measured the number average molecular weight of the polymer D-2 to be 208,000 and the molecular weight distribution to be 1.45. 1 The mass percentage of styrene units in the polymer D-2 measured by H-NMR was 29.8%.

[0165] Example 3

[0166] (1) Preparation of dilithium initiator

[0167] First, nitrogen was passed into a 100 mL flask for replacement 4 times, and then 35 mL of cyclopentane was added as a solvent, and then 0.57 mL of a cyclopentane solution of 1,3-diisopropenylbenzene (volume concentration 10%) and 1.39 mL of a cyclopentane solution of triethylamine (volume concentration 10%) were added in sequence, and 0.59 mL of a tert-butyl lithium solution (1.7 mol / L) was slowly added at -20°C with stirring, and after reacting for 3 hours, a dilithium initiator was obtained;

[0168] (2) Preparation of styrene-butadiene polymer active chains

[0169] First, a 3L stainless steel reactor with a jacket was replaced with nitrogen three times, and then 1.3kg of xylene, 54g of styrene, 126g of butadiene, 3.2mL of a cyclopentane solution of tetramethylethylenediamine (volume concentration 10%), and 3mL of a cyclopentane solution of tetrahydrofuran (volume concentration 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 30°C, 0.15mL of tert-butyl lithium solution (1.7mol / L) was added and reacted for 10min to remove impurities in the system, and then the temperature was continuously raised to 45°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 40min to obtain a system containing active chains of styrene-butadiene polymer;

[0170] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0171] Add 1.4 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 40° C., react for 120 min, add 2.1 mL of a 1 mol / L tetrahydrofuran solution of maleic anhydride, react for 120 min, add 5 mL of a 1 mol / L ethanol solution of nitric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0172] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0173] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), add 0.3 mL of [diethoxy(3-methylpent-3-yloxy)silyl]methylamine, maintain the temperature in the reactor at 40°C, react for 120 minutes, discharge the material, and after rotary evaporation and drying, obtain a double-terminal siloxane-based styrene-butadiene polymer P-3.

[0174] GPC measured the number average molecular weight of the polymer P-3 to be 176,300 and the molecular weight distribution to be 1.04. 1The mass percentage of styrene units in the polymer P-3 measured by H-NMR was 30.2%.

[0175] Example 4

[0176] (1) Preparation of dilithium initiator

[0177] First, nitrogen was passed into a 100 mL flask for replacement 5 times, and then 40 mL of cyclopentane was added as a solvent, and then 0.76 mL of a cyclopentane solution of 1,4-diisopropenylbenzene (volume concentration 10%) and 1.25 mL of a cyclopentane solution of triethylamine (volume concentration 10%) were added in sequence, and 0.53 mL of a tert-butyl lithium solution (1.7 mol / L) was slowly added at -20°C with stirring, and after reacting for 2 hours, a dilithium initiator was obtained;

[0178] (2) Preparation of styrene-butadiene polymer active chains

[0179] First, a 3L stainless steel reactor with a jacket was replaced with nitrogen for 3 times, and then 1.3kg of toluene, 135g of butadiene, 45g of styrene, and 1.87mL of a cyclopentane solution of diethylene glycol dimethyl ether (volume concentration 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 40°C, 0.24mL of tert-butyl lithium solution (1.7mol / L) was added and reacted for 20min to remove impurities in the system, and then the temperature was continuously raised to 60°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 20min to obtain a system containing active chains of styrene-butadiene polymer;

[0180] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0181] Add 0.3 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 130° C., react for 10 min, add 2.7 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, react for 50 min, add 7.2 mL of a 1 mol / L methanol solution of sulfuric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0182] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0183] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), 0.76 mL of 4-anilinotriethoxysilane was added, the temperature in the reactor was maintained at 100° C., and the reaction was carried out for 30 minutes before discharging the material. After rotary evaporation and drying, a double-terminal siloxane-based styrene-butadiene polymer P-4 was obtained.

[0184] GPC measured the number average molecular weight of the polymer P-4 to be 198,800 and the molecular weight distribution to be 1.06. 1 The mass percentage of styrene units in the polymer P-4 measured by H-NMR was 25.2%.

[0185] Example 5

[0186] (1) Preparation of dilithium initiator

[0187] First, nitrogen was passed into a 100 mL flask for replacement 5 times, and then 40 mL of cyclopentane was added as a solvent, and then 0.30 mL of a cyclopentane solution of 1,4-diisopropenylbenzene (volume concentration 10%) and 1.0 mL of a cyclopentane solution of triethylamine (volume concentration 10%) were added in sequence, and 0.55 mL of a sec-butyllithium solution (1.3 mol / L) was slowly added at -20°C with stirring, and after reacting for 2 hours, a dilithium initiator was obtained;

[0188] (2) Preparation of styrene-butadiene polymer active chains

[0189] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three times, and then 1.3kg of ethylbenzene, 54g of styrene, 126g of butadiene, and 3.2mL of a cyclopentane solution of tetramethylethylenediamine (volume concentration of 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 32°C, 0.22mL of a sec-butyllithium solution (1.3mol / L) was added and reacted for 30min to remove impurities in the system, and then the temperature was continuously raised to 45°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 35min to obtain a system containing active chains of styrene-butadiene polymer;

[0190] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0191] Add 0.9 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 60° C., react for 40 min, add 4.2 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, react for 90 min, add 4.3 mL of a 1 mol / L ethanol and butanol solution of sulfuric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0192] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0193] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), 0.5 mL of (anilinomethyl)methyldimethoxysilane was added, the temperature in the reactor was maintained at 130° C., and the material was discharged after reacting for 10 minutes. After rotary evaporation and drying, a double-terminal siloxane-based styrene-butadiene polymer P-5 was obtained.

[0194] GPC measured the number average molecular weight of the polymer P-5 to be 248100 and the molecular weight distribution to be 1.05. 1 The mass percentage of styrene units in the polymer P-5 measured by H-NMR was 29.8%.

[0195] Example 6

[0196] (1) Preparation of dilithium initiator

[0197] First, nitrogen was passed into a 100 mL flask for replacement three times, and then 45 mL of cyclopentane was added as a solvent, and then 0.70 mL of a cyclopentane solution of 1,3-divinylbenzene (volume concentration 10%) and 0.80 mL of a cyclopentane solution of tetrahydrofuran (volume concentration 10%) were added in sequence, and 0.77 mL of a sec-butyllithium solution (1.3 mol / L) was slowly added at 40° C. with stirring, and after reacting for 1 hour, a dilithium initiator was obtained;

[0198] (2) Preparation of styrene-butadiene polymer active chains

[0199] First, a 3L stainless steel reactor with a jacket was replaced with nitrogen three times, and then 1.3kg of xylene, 54g of styrene, 126g of butadiene, 3.2mL of a cyclopentane solution of tetramethylethylenediamine (volume concentration 10%), and 3mL of a cyclopentane solution of tetrahydrofuran (volume concentration 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 35°C, 0.62mL of a n-butyllithium solution (1.6mol / L) was added and reacted for 25min to remove impurities in the system, and then the temperature was continuously raised to 50°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 40min to obtain a system containing active chains of styrene-butadiene polymer;

[0200] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0201] Add 1.4 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 40° C., react for 120 min, add 2.1 mL of a 1 mol / L tetrahydrofuran solution of maleic anhydride, react for 120 min, add 5 mL of a 1 mol / L ethanol solution of nitric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0202] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0203] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), add 0.3 mL of [diethoxy(3-methylpent-3-yloxy)silyl]methylamine, maintain the temperature in the reactor at 40°C, react for 120 minutes, discharge the material, and obtain a double-terminal siloxane-based styrene-butadiene polymer P-6 after rotary evaporation and drying.

[0204] GPC measured the number average molecular weight of the polymer P-6 to be 180230 and the molecular weight distribution to be 1.11. 1 The mass percentage of styrene units in the polymer P-6 measured by H-NMR was 30.2%.

[0205] Comparative Example 3

[0206] The difference from Example 6 is that 0.3 mL of [diethoxy(3-methylpent-3-yloxy)silyl]methylamine in step (4) is replaced with 0.23 mL of 3-chloropropyltrimethoxysilane to obtain a dual-terminal siloxane-based styrene-butadiene polymer D-3.

[0207] GPC measured the number average molecular weight of the polymer D-3 to be 195200 and the molecular weight distribution to be 1.19. 1 The mass percentage of styrene units in the polymer D-3 measured by H-NMR was 30.1%.

[0208] This comparative example adopts the reaction of halogenated siloxane and double-terminal carboxyl-containing styrene-butadiene polymer. In addition to the reaction of the halogenated group with the active site of the double-terminal carboxyl-containing styrene-butadiene polymer, there are also cases of silicon-oxygen bond breakage and polymer molecular chain coupling, and the number of broken bonds is unstable, which makes the molecular weight distribution of the polymer D-3 of this comparative example wider, and the molecular weight and performance are difficult to control.

[0209] Example 7

[0210] (1) Preparation of dilithium initiator

[0211] First, nitrogen was passed into a 100 mL flask for replacement three times, and then 50 mL of cyclopentane was added as a solvent, and then 1.28 mL of a cyclopentane solution of 1,4-divinylbenzene (volume concentration 10%) and 2.5 mL of a cyclopentane solution of tetrahydrofurfuryl alcohol ethyl ether (volume concentration 10%) were added in sequence, and 1.13 mL of an n-butyl lithium solution (1.6 mol / L) was slowly added at 45° C. with stirring, and after reacting for 3 hours, a dilithium initiator was obtained;

[0212] (2) Preparation of styrene-butadiene polymer active chains

[0213] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three times, and then 1.0kg of heptane, 50g of styrene, 130g of butadiene, and 1.0mL of a cyclopentane solution of tetrahydrofuran (volume concentration of 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 20°C, 0.25mL of n-butyl lithium solution (1.6mol / L) was added and reacted for 5min to remove impurities in the system, and then the temperature was continuously raised to 40°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 30min to obtain a system containing active chains of styrene-butadiene polymer;

[0214] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0215] Add 3 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 65° C., react for 40 min, add 9 mL of a 1 mol / L tetrahydrofuran solution of methylsuccinic anhydride, react for 10 min, then add 10 mL of a 1 mol / L butanol solution of hydrochloric acid to terminate the reaction, thereby obtaining a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0216] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0217] Add 0.7 mL of 3-aminopropyldimethylmethoxysilane to the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 120° C., react for 60 minutes, discharge the material, and obtain a double-terminal siloxane-based styrene-butadiene polymer P-7 after rotary evaporation and drying.

[0218] GPC measured the number average molecular weight of the polymer P-7 to be 96,400 and the molecular weight distribution to be 1.10. 1 The mass percentage of styrene units in the polymer P-7 measured by H-NMR was 27.7%.

[0219] Example 8

[0220] (1) Preparation of dilithium initiator

[0221] First, nitrogen was passed into a 100 mL flask for replacement three times, and then 45 mL of cyclopentane was added as a solvent, and then 0.30 mL of a cyclopentane solution of 1,2-divinylbenzene (volume concentration 10%) and 0.94 mL of a cyclopentane solution of pentamethyldivinyltriamine (volume concentration 10%) were added in sequence, and 0.40 mL of an n-butyllithium solution (1.6 mol / L) was slowly added at 50° C. with stirring, and after reacting for 5 hours, a dilithium initiator was obtained;

[0222] (2) Preparation of styrene-butadiene polymer active chains

[0223] First, a 3L stainless steel reactor with a jacket was replaced with nitrogen for 3 times, and then 1.3kg of benzene, 50g of styrene, 130g of butadiene, and 0.5mL of a cyclopentane solution of tetrahydrofurfuryl alcohol ethyl ether (volume concentration 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 30°C, 0.30mL of n-butyl lithium solution (1.6mol / L) was added and reacted for 30min to remove impurities in the system, and then the temperature was continuously raised to 50°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 50min to obtain a system containing active chains of styrene-butadiene polymer;

[0224] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0225] Add 0.5 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 40° C., react for 110 min, add 1.35 mL of a 1 mol / L tetrahydrofuran solution of phthalic anhydride, react for 50 min, then add 2.3 mL of a 1 mol / L butanol solution of hydrochloric acid to terminate the reaction, thereby obtaining a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0226] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0227] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), 0.61 mL of cyclohexylaminopropyltrimethoxysilane was added, the temperature in the reactor was maintained at 80° C., and the reaction was carried out after 120 min of reaction. After rotary evaporation and drying, a double-terminal siloxane-based styrene-butadiene polymer P-8 was obtained.

[0228] GPC measured the number average molecular weight of the polymer P-8 to be 399100 and the molecular weight distribution to be 1.03. 1 The mass percentage of styrene units in the polymer P-8 measured by H-NMR was 28.1%.

[0229] Example 9

[0230] (1) Preparation of dilithium initiator

[0231] First, nitrogen was passed into a 100 mL flask for replacement three times, and then 50 mL of cyclopentane was added as a solvent, and then 0.20 mL of a cyclopentane solution of 1,3-divinylbenzene (volume concentration 10%) and 0.42 mL of a cyclopentane solution of triethylamine (volume concentration 10%) were added in sequence, and 0.23 mL of an n-butyl lithium solution (1.6 mol / L) was slowly added at 50° C. with stirring, and the reaction was continued for 6 hours to obtain a dilithium initiator;

[0232] (2) Preparation of styrene-butadiene polymer active chains

[0233] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three times, and then cyclopentane 1.1kg, styrene 18g, butadiene 162g, and cyclopentane solution of tetrahydrofurfuryl alcohol ethyl ether (volume concentration 10%) 3.7mL were added into the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 40°C, 0.25mL of n-butyl lithium solution (1.6mol / L) was added and reacted for 20min to remove impurities in the system, and then the temperature was maintained at 40°C, and all the dilithium initiator obtained in step (1) was added into the reactor, and after the temperature rose to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 60min to obtain a system containing active chains of styrene-butadiene polymer;

[0234] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0235] Add 0.6 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 80° C., react for 120 min, add 1.8 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, react for 60 min, then add 3 mL of a 1 mol / L ethanol solution of hydrochloric acid to terminate the reaction, thereby obtaining a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0236] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0237] Add 0.35 mL of 3-aminopropyltriethoxysilane to the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 90° C., react for 100 minutes, discharge the material, and obtain a double-terminal siloxane-based styrene-butadiene polymer P-9 after rotary evaporation and drying.

[0238] GPC measured the number average molecular weight of the polymer P-9 to be 599,000 and the molecular weight distribution to be 1.06. 1 The mass percentage of styrene units in the polymer P-9 measured by H-NMR was 10.1%.

[0239] Example 10

[0240] (1) Preparation of dilithium initiator

[0241] First, nitrogen was passed into a 200 mL flask for replacement three times, and then 50 mL of cyclopentane was added as a solvent, and then 15.3 mL of a cyclopentane solution of 1,4-diisopropenylbenzene (volume concentration 20%) and 25 mL of a cyclopentane solution of triethylamine (volume concentration 20%) were added in sequence, and 22.7 mL of an n-butyl lithium solution (1.6 mol / L) was slowly added at -15°C with stirring, and after reacting for 3 hours, a dilithium initiator was obtained;

[0242] (2) Preparation of styrene-butadiene polymer active chains

[0243] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three times, and then 1.1kg of cyclopentane, 63g of styrene, 117g of butadiene, and 28mL of a cyclopentane solution of ethylene glycol dimethyl ether (volume concentration 20%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 20°C, 0.15mL of n-butyl lithium solution (1.6mol / L) was added and reacted for 15min to remove impurities in the system, and then the temperature was continuously raised to 30°C, and all the dilithium initiator obtained in step (1) was added to the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 55min to obtain a system containing active chains of styrene-butadiene polymer;

[0244] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0245] Add 12 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 40° C., react for 120 min, add 36 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, raise the temperature in the reactor to 55° C., react for 35 min, then add 36 mL of a 1 mol / L ethanol solution of hydrochloric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0246] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0247] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), 8.5 mL of 3-aminopropyldimethylmethoxysilane was added, the temperature in the reactor was maintained at 65° C., and the reaction was carried out for 50 minutes before discharging the material. After rotary evaporation and drying, a double-terminal siloxane-based styrene-butadiene polymer P-10 was obtained.

[0248] GPC measured the number average molecular weight of the polymer P-10 to be 5160 and the molecular weight distribution to be 1.09. 1 The mass percentage of styrene units in the polymer P-10 measured by H-NMR was 34.9%.

[0249] Embodiment 11

[0250] (1) Preparation of dilithium initiator

[0251] First, nitrogen was passed into a 100 mL flask for replacement three times, and then 30 mL of cyclopentane was added as a solvent, and then 1.1 mL of a cyclopentane solution of 1,2-divinylbenzene (volume concentration 10%) and 1.22 mL of a cyclopentane solution of tetrahydrofuran (volume concentration 10%) were added in sequence, and 0.92 mL of an n-butyl lithium solution (1.6 mol / L) was slowly added at 60° C. with stirring, and after reacting for 3 hours, a dilithium initiator was obtained;

[0252] (2) Preparation of styrene-butadiene polymer active chains

[0253] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three times, and then octane 1.3kg, butadiene 90g, styrene 90g, tetrahydrofuran cyclopentane solution (volume concentration 10%) 4.3mL, diethylene glycol dimethyl ether cyclopentane solution (volume concentration 10%) 3.2mL were added into the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 40°C, 0.2mL of n-butyl lithium solution (1.6mol / L) was added and reacted for 5min to remove impurities in the system, and then the temperature was continuously raised to 45°C, and all the dilithium initiator obtained in step (1) was added into the reactor, and after the temperature was raised to a temperature that did not continue to rise (i.e., the highest temperature), the reaction was continued for 25min to obtain a system containing active chains of styrene-butadiene polymer;

[0254] (3) Preparation of double-terminal carboxyl-containing styrene-butadiene polymers

[0255] Add 1 mL of a 3 mol / L tetrahydrofuran solution of ethylene oxide to the system containing active chains of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 90° C., react for 30 min, add 4.5 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, react for 30 min, add 8 mL of a 1 mol / L ethanol solution of hydrochloric acid to terminate the reaction, and obtain a system containing a double-terminal carboxyl-containing styrene-butadiene polymer;

[0256] (4) Preparation of dual-terminal siloxane styrene-butadiene polymer

[0257] To the system containing the double-terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), 1.5 mL of 4-anilinotriethoxysilane was added, the temperature in the reactor was maintained at 65° C., and the reaction was carried out after 70 minutes of reaction. After rotary evaporation and drying, a double-terminal siloxane-based styrene-butadiene polymer P-11 was obtained.

[0258] GPC measured the number average molecular weight of the polymer P-11 to be 122,000 and the molecular weight distribution to be 1.04. 1 The mass percentage of styrene units in the polymer P-11 measured by H-NMR was 50.2%.

[0259] Example 12

[0260] 100 parts by weight of the polymer P-1 provided in Example 1, 50 parts by weight of white carbon black, 2 parts by weight of zinc oxide, 1.2 parts by weight of stearic acid, 2 parts by weight of sulfur, 2.5 parts by weight of vulcanization accelerator DM, 1.5 parts by weight of antioxidant 4021A, 10 parts by weight of coupling agent KH550, and 10 parts by weight of filler oil A1820 were mixed on a mixer for 10 minutes, and the obtained mixed rubber was vulcanized on a flat vulcanizer at a temperature of 120° C. and a pressure of 13 MPa for 12 minutes to obtain vulcanized rubber S-1.

[0261] Comparative Example 4

[0262] Vulcanized rubber SD-1 was prepared according to the method of Example 12, which differed from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer D-1 provided in Comparative Example 1.

[0263] Example 13

[0264] Vulcanized rubber S-2 was prepared according to the method of Example 12, which differs from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-2 provided in Example 2, and the reinforcing agent was 55 parts by weight of white carbon black, the amount of sulfur was 3 parts by weight, the amount of zinc oxide was 0.5 parts by weight, and the amount of stearic acid was 0.5 parts by weight.

[0265] Comparative Example 5

[0266] Vulcanized rubber SD-2 was prepared according to the method of Example 13, which differed from Example 13 in that the polymer P-2 provided in Example 2 was replaced by the polymer D-2 provided in Comparative Example 2.

[0267] Embodiment 14

[0268] Vulcanized rubber S-3 was prepared according to the method of Example 12, which differs from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-3 provided in Example 3, the reinforcing agent was 60 parts by weight of white carbon black, the amount of sulfur was 0.5 parts by weight, and the extending oils were 10 parts by weight of N4010 and 5 parts by weight of N4016.

[0269] Embodiment 15

[0270] Vulcanized rubber S-4 was prepared according to the method of Example 12, which differs from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-4 provided in Example 4, and the reinforcing agent was 40 parts by weight of white carbon black, the amount of zinc oxide was 2.2 parts by weight, and the amount of stearic acid was 1.8.

[0271] Example 16

[0272] Vulcanized rubber S-5 was prepared according to the method of Example 12, which differs from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-5 provided in Example 5, and the reinforcing agent was 45 parts by weight of white carbon black, the coupling agent was 3.5 parts by weight of coupling agent Si69, the vulcanization accelerator was 1 part by weight of DM, and the antioxidant was 5 parts by weight of 4021A.

[0273] Embodiment 17

[0274] Vulcanized rubber S-6 was prepared according to the method of Example 12, which differed from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-6 provided in Example 6, and the coupling agent was 7 parts by weight of coupling agent KH590, the vulcanization accelerator was 5 parts by weight of vulcanization accelerator TBBS, and the filler oil was 2 parts by weight of A1426.

[0275] Comparative Example 6

[0276] Vulcanized rubber SD-3 was prepared according to the method of Example 17, which differed from Example 17 in that the polymer P-6 provided in Example 6 was replaced by the polymer D-3 provided in Comparative Example 3.

[0277] Embodiment 18

[0278] Vulcanized rubber S-7 was prepared according to the method of Example 12, which differed from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-7 provided in Example 7, and the coupling agents were 2.5 parts by weight of coupling agent KH550 and 2.5 parts by weight of coupling agent KH570.

[0279] Embodiment 19

[0280] Vulcanized rubber S-8 was prepared according to the method of Example 12, which differs from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-8 provided in Example 8, the reinforcing agent was 30 parts by weight of white carbon black, and the vulcanization accelerators were 3 parts by weight of accelerator D and 1 part by weight of accelerator NS.

[0281] Embodiment 20

[0282] Vulcanized rubber S-9 was prepared according to the method of Example 12, which differed from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-9 provided in Example 9, and the reinforcing agent was 70 parts by weight of white carbon black, the coupling agent was 12 parts by weight of coupling agent KH560, and the extending oils were 12 parts by weight of A1820 and 8 parts by weight of A1426.

[0283] Embodiment 21

[0284] Vulcanized rubber S-11 was prepared according to the method of Example 12, which differed from Example 12 in that the polymer P-1 provided in Example 1 was replaced by the polymer P-11 provided in Example 11, the reinforcing agent was 60 parts by weight of white carbon black, the coupling agent was 6 parts by weight of coupling agent KH580, and the amount of antioxidant 4021A was 0.5 parts by weight.

[0285] The physical properties and dynamic mechanical properties of the vulcanized rubbers provided in Examples 12 to 21 and Comparative Examples 4 to 6 are shown in Table 1.

[0286] Table 1

[0287]

[0288] In Table 1, tanδ(0℃) characterizes the anti-slip property of the rubber, and the larger its value, the better its anti-slip property; tanδ(60℃) characterizes the rolling resistance of the rubber, and the smaller its value, the smaller its rolling resistance; Akron wear volume characterizes the wear resistance of the rubber, and the lower its value, the better its wear resistance. From the above data, it can be seen that the preparation method of the present invention greatly reduces the occurrence of the side reaction of Si-O bond rupture, and even prevents the side reaction from occurring, thereby reducing the generation of polyploids of the polymer chain, and even preventing the generation of polyploids of the polymer chain, making the structure and molecular weight of the polymer easy to control, thereby stabilizing its performance. The double-ended siloxane styrene-butadiene polymer provided by the present invention contains a group having good compatibility with carbon black / white carbon black, and has a high content of functional groups, and both ends contain functional groups, thereby improving the interaction between the polymer matrix and the carbon black / white carbon black, and the mechanical strength, wear resistance, and anti-slip property of the vulcanized rubber finally obtained are significantly improved, and the rolling resistance is reduced.

Claims

1. A method for preparing a dual-terminal siloxane-based styrene-butadiene polymer, comprising the following steps: (1) reacting a first hydrocarbon monolithium with a dienylbenzene to obtain a dilithium initiator; (2) using the dilithium initiator to initiate an anionic polymerization reaction of butadiene and styrene in a solvent to obtain a system containing active chains of styrene-butadiene polymer; (3) using a dibasic acid anhydride to end-cap the active chains of the styrene-butadiene polymer to obtain a system containing a dual-terminal carboxyl functionalized polymer; (4) using aminosiloxane to react with the dual-terminal carboxyl functionalized polymer to obtain the dual-terminal siloxane-based styrene-butadiene polymer.

2. The preparation method according to claim 1, wherein The general formula of the first hydrocarbon monolithium is: R5Li, wherein R5 is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of two or more of them containing 1 to 20 carbon atoms; Preferably, the first hydrocarbon monolithium includes one or a combination of n-butyllithium, sec-butyllithium, tert-butyllithium, phenylbutyllithium, naphthyllithium, cyclohexyllithium and dodecyllithium.

3. The preparation method according to claim 1, wherein The dienylbenzene includes one or a combination of o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, o-diisopropenylbenzene, m-diisopropenylbenzene and p-diisopropenylbenzene.

4. The preparation method according to claim 1, wherein The reaction of the first hydrocarbon monolithium with the dienylbenzene is carried out in the presence of a polar compound and a hydrocarbon solvent, wherein the polar compound comprises one or a combination of tetrahydrofuran, tetrahydrofurfuryl alcohol ethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetramethylethylenediamine, triethylamine and pentamethyldivinyltriamine; Preferably, the molar ratio of the dienylbenzene, the polar compound and the first hydrocarbon monolithium is 1:2-4:2-4.

5. The preparation method according to claim 1, wherein In step (1), the reaction temperature of the first hydrocarbon monolithium and the dienylbenzene is -20°C to 60°C, and the reaction time is 1 to 6 hours.

6. The preparation method according to claim 1, wherein Based on the total weight of styrene and butadiene being 100%, the amount of styrene used is 10% to 50%, and the amount of butadiene used is 90% to 50%.

7. The preparation method according to claim 1, wherein Step (2) further comprises: adding a structure regulator and then performing the anionic polymerization reaction, wherein the structure regulator comprises one or a combination of tetrahydrofuran, tetrahydrofurfuryl alcohol ethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetramethylethylenediamine, triethylamine and pentamethyldivinyltriamine; Preferably, the molar ratio of the structure regulator to the first hydrocarbon monolithium is 0.8-10.0:

1.

8. The preparation method according to claim 7, wherein: Step (2) specifically comprises: adding the butadiene, the styrene and the structure regulator into a solvent, adding an appropriate amount of a second hydrocarbon monolithium when the temperature reaches 20°C to 40°C to react for 5 to 30 minutes, then maintaining the temperature at 20°C to 40°C or raising the temperature to 40°C to 60°C, adding the dilithium initiator obtained in step (1) to carry out anionic polymerization reaction, and after the temperature rises to a point where it stops rising, continuing the reaction for 10 to 60 minutes to obtain a system containing active chains of styrene-butadiene polymers.

9. The preparation method according to claim 1, wherein The dibasic acid anhydride includes one or a combination of maleic anhydride, succinic anhydride, methylsuccinic anhydride and phthalic anhydride; Preferably, the molar ratio of the dibasic acid anhydride to the first hydrocarbon monolithium is 1-6:

1.

10. The preparation method according to claim 1, wherein: Step (3) specifically comprises: adding ethylene oxide to the system containing the active chain of styrene-butadiene polymer obtained in step (2), reacting at 40° C. to 130° C. for 10 to 120 minutes, adding dibasic acid anhydride, reacting for another 10 to 120 minutes, and terminating the reaction with a terminator to obtain a system containing a dual-end carboxyl functionalized polymer; Preferably, the molar ratio of the ethylene oxide to the first hydrocarbon monolithium is 1 to 6:

1.

11. The preparation method according to claim 1, wherein: The general formula of the aminosiloxane is: wherein R1 is a hydrogen atom, a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms; R2 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms; R3 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, or a cycloalkyl group containing 3 to 10 carbon atoms; R4 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms, or an aryl group containing 6 to 10 carbon atoms; x is 1 to 3; y is 0 to 2; and x+y=3; Preferably, the aminosiloxane comprises one or a combination of 4-anilinotriethoxysilane, cyclohexylaminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (anilinomethyl)methyldimethoxysilane, [diethoxy(3-methylpent-3-yloxy)silyl]methylamine and 3-aminopropyldimethylmethoxysilane; Preferably, the molar ratio of the aminosiloxane to the first hydrocarbon monolithium is 1-5:

1.

12. The preparation method according to claim 1, wherein: In step (4), the reaction temperature of the aminosiloxane and the dual-end carboxyl functionalized polymer is 40° C. to 130° C., and the reaction time is 10 to 120 min.

13. A dual-terminal siloxane-based styrene-butadiene polymer, which is prepared by the method for preparing a dual-terminal siloxane-based styrene-butadiene polymer according to any one of claims 1 to 12.

14. The dual-terminal siloxane-based styrene-butadiene polymer according to claim 13, wherein: The general formula of the dual-terminal siloxane styrene-butadiene polymer is: in, is a styrene-butadiene polymer chain, P is -CH=CH-, -CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)- or -C6H4-, R1 is a hydrogen atom, a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, R2 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, R3 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms or a cycloalkyl group containing 3 to 10 carbon atoms, R4 is a straight chain or branched chain alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 3 to 10 carbon atoms or an aryl group containing 6 to 10 carbon atoms, x is 1 to 3, y is 0 to 2, and x+y=3; Preferably, the molecular weight of the dual-terminal siloxane-based styrene-butadiene polymer is 5,000 to 600,000.

15. A rubber composition comprising: 100 parts by weight of the double-ended siloxane styrene-butadiene polymer according to claim 13 or 14, 30 to 70 parts by weight of a reinforcing agent, 0.5 to 3 parts by weight of a vulcanizing agent, 1 to 4 parts by weight of a vulcanization activator, 1 to 5 parts by weight of a vulcanization accelerator, 0.5 to 5 parts by weight of an antioxidant, 2 to 20 parts by weight of an extender oil, and 3.5 to 12 parts of a coupling agent.

16. A vulcanized rubber prepared by mixing and vulcanizing the rubber composition according to claim 15.

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