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

Abstract

The invention provides a double-end multifunctional styrene-butadiene polymer, a preparation method thereof, a rubber composition and vulcanized rubber. The preparation method comprises the following steps: reacting alkyl monolithium with a nitrogen-containing compound to obtain a functionalized initiator; initiating a polymerization reaction of butadiene and styrene by adopting the functionalized initiator; blocking by adopting binary anhydride to obtain a carboxyl-terminated functionalized polymer; amino siloxane and the carboxyl-terminated functionalized polymer are subjected to a reaction, and the double-terminated multi-functionalized styrene-butadiene polymer is obtained. The rubber composition provided by the invention comprises the double-end polyfunctional 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 multifunctional 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 end and the end of the molecular chain contain functional groups and its functional group content is relatively high, can further improve the dispersion of the filler in the rubber matrix, thereby improving the overall performance of the rubber.

[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] CN111793179A discloses a brush-shaped multifunctional rubber polymer and its preparation method and application. The method synthesizes a novel nitrogen-containing styrene derivative monomer, and then anion polymerizes it with a traditional conjugated olefin. In addition, the method sequentially adds an organic solvent, a monomer, and an initiator, and controls the order of adding different monomers and the reaction time. After the monomers are completely converted, the obtained polymer active chain and the corresponding terminator are subjected to a chain termination reaction. The brush-shaped multifunctional rubber polymer has the characteristics of controllable molecular weight, uniform molecular weight distribution, and high functionality, and can therefore be used in the field of rubber tires.

[0011] 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 siloxane terminalization 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 monolithium initiator to initiate the polymerization of butadiene and styrene, and uses a siloxane reagent for end-capping, 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. Summary of the invention

[0012] In order to solve the above technical problems, the object of the present invention is to provide a double-end multifunctional styrene butadiene polymer and a preparation method thereof, a rubber composition and a vulcanized rubber. The method of the present invention makes it easy to control the molecular weight of the prepared polymer, thereby stabilizing the performance of the polymer. The double ends of the polymer of the present invention contain multiple functional groups, which improves the dispersion performance of the filler in the polymer matrix.

[0013] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a double-end multi-functionalized butadiene styrene polymer, which comprises the following steps:

[0014] (1) reacting a hydrocarbon monolithium with a nitrogen-containing compound to obtain a functionalized initiator;

[0015] (2) using the functionalized 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;

[0016] (3) using a dibasic acid anhydride to end-cap the active chains of the styrene-butadiene polymer to obtain a system containing a terminal carboxyl functionalized polymer;

[0017] (4) Using aminosiloxane to react with the terminal carboxyl functionalized polymer to obtain the dual-terminal multi-functionalized butadiene styrene polymer.

[0018] The preparation method of the present invention first uses nitrogen-containing compounds and hydrocarbon monolithium to prepare a functionalized initiator, then uses the functionalized initiator to initiate the polymerization of butadiene and styrene to prepare a solution-polymerized butadiene styrene molecular chain containing a nitrogen-containing functional group at one end and a lithium active center at the other end, then uses a dibasic acid anhydride to carboxylate one end of the molecular chain containing the lithium active center, and finally uses aminosiloxane to react with the carboxyl group at the end of the solution-polymerized butadiene styrene molecular chain to prepare a double-ended multifunctional solution-polymerized butadiene styrene rubber. One end of the double-ended multifunctional solution-polymerized butadiene styrene rubber contains a nitrogen-containing group, and the other end contains functional groups such as a carbonyl group, an ester group, a siloxane group, and a nitrogen atom. 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 agent are difficult to control and the performance is unstable. At the same time, since the molecular chains of the polymers prepared by the present invention contain various types of functional groups at both ends, the dispersibility of fillers such as carbon black and white carbon black in the polymer matrix is ​​improved, so that the strength of the final rubber is improved, the rolling resistance is reduced, and the anti-skid performance is improved, and the wear resistance, rolling resistance and anti-skid performance (referred to as the "devil's triangle") are better balanced.

[0019] In the above preparation method, preferably, the general formula of the 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 hydrocarbon monolithium includes one or a combination of n-butyllithium, sec-butyllithium, tert-butyllithium, phenylbutyllithium, naphthyllithium, cyclohexyllithium and dodecyllithium.

[0020] In the above preparation method, preferably, the nitrogen-containing compound includes one or a combination of cycloheximide, tetrahydropyrrole, morpholine, maleimide, tetramethylpiperidone, phthalimide and tetrahydropyridine.

[0021] In the above preparation method, preferably, the molar ratio of the nitrogen-containing compound to the hydrocarbon monolithium is 1 to 3:1.

[0022] In the above preparation method, preferably, in step (1), the reaction time of the hydrocarbon monolithium and the nitrogen-containing compound is 1 to 50 minutes. The reaction can be carried out at normal temperature and 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 and tetramethylethylenediamine.

[0025] In the above preparation method, preferably, the molar ratio of the structure regulator to the 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 into a solvent, adding the functionalized initiator obtained in step (1) to carry out anionic polymerization when the temperature reaches 20 to 60°C, and after the temperature rises to a point where it does not continue to rise, continuing the reaction for 10 to 60 minutes to obtain a system containing active chains of styrene-butadiene polymer. The present invention does not impose any particular restriction 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, preferably, the dibasic acid anhydride includes one or a combination of maleic anhydride, succinic anhydride, methylsuccinic anhydride and phthalic anhydride.

[0028] In the above preparation method, preferably, the molar ratio of the dibasic acid anhydride to the hydrocarbon monolithium is 1 to 6:1.

[0029] 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 40-130° C. for 10-120 minutes, adding dibasic acid anhydride, reacting for another 10-120 minutes, and terminating the reaction with a terminator to obtain a system containing a terminal carboxyl functionalized polymer. The present invention does not impose any particular restriction on the reaction pressure of step (3).

[0030] In the above preparation method, preferably, the molar ratio of the ethylene oxide to the hydrocarbon monolithium is 1 to 6:1.

[0031] 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.

[0032] In the above preparation method, preferably, the molar ratio of the aminosiloxane to the hydrocarbon monolithium is 1 to 5:1.

[0033] In the above preparation method, preferably, in step (4), the reaction temperature of the aminosiloxane and the terminal carboxyl functionalized polymer is 40-130° C., and the reaction time is 10-120 min. The present invention does not impose any particular limitation on the reaction pressure of step (4).

[0034] The second aspect of the present invention provides a dual-terminal multi-functionalized butadiene styrene polymer, which is prepared by the above-mentioned preparation method of the dual-terminal multi-functionalized butadiene styrene polymer.

[0035] According to a specific embodiment of the present invention, preferably, the general formula of the double-terminal multi-functionalized butadiene styrene polymer is:

[0036]

[0037] in, include:

[0038]

[0039] 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 number average molecular weight of the dual-end multi-functionalized butadiene styrene polymer is 5,000 to 600,000.

[0041] The double-end multifunctional styrene butadiene polymer provided by the present invention contains functional groups such as nitrogen atoms, carbonyl groups, ester groups, and siloxane groups. At least the nitrogen-containing groups can interact with the functional groups on the surface of carbon black to promote the dispersion of fillers; at least the siloxane groups can effectively improve the affinity between the polymer and white carbon black and promote the dispersion of white carbon black. The double-end multifunctional 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 multi-functional butadiene styrene 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 method of the present invention carboxylates a single end of the polymer, and then reacts the carboxylated end of the polymer with an aminosiloxane functionalizing agent, which greatly reduces the occurrence of the side reaction of Si-O bond cleavage, 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.

[0047] 2. Both ends of the styrene butadiene polymer prepared by the method of the present invention contain functional groups. The double-ended multi-functional styrene butadiene polymer of the present invention contains functional groups such as ester groups, carbonyl groups, siloxane groups, amide groups, and vinyl 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-skid performance of the final vulcanized rubber, reducing rolling resistance, and better balancing the "devil's triangle".

[0048] 3. The preparation method of the double-terminal multifunctionalized butadiene styrene polymer of the present invention has a simple process and mild reaction conditions, can be carried out in an anion solution polymerization device in the prior art, and can be implemented on an industrial scale. DETAILED DESCRIPTION

[0049] 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.

[0050] According to a specific embodiment of the present invention, the first aspect of the present invention provides a method for preparing a double-terminal multi-functionalized butadiene styrene polymer, which comprises the following steps:

[0051] (1) reacting a hydrocarbon monolithium with a nitrogen-containing compound to obtain a functionalized initiator;

[0052] (2) using the functionalized 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;

[0053] (3) using a dibasic acid anhydride to end-cap the active chains of the styrene-butadiene polymer to obtain a system containing a terminal carboxyl functionalized polymer;

[0054] (4) Using aminosiloxane to react with the terminal carboxyl functionalized polymer to obtain the dual-terminal multi-functionalized butadiene styrene polymer.

[0055] In some embodiments, the general formula of the 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. Preferably, the hydrocarbon monolithium includes one or a combination of n-butyllithium, sec-butyllithium, tert-butyllithium, phenylbutyllithium, naphthyllithium, cyclohexyllithium and dodecyllithium. More preferably, the hydrocarbon monolithium is n-butyllithium.

[0056] In some embodiments, the nitrogen-containing compound includes one or a combination of cycloheximide, tetrahydropyrrole, morpholine, maleimide, tetramethylpiperidone, phthalimide and tetrahydropyridine.

[0057] In some embodiments, the molar ratio of the nitrogen-containing compound to the hydrocarbon monolithium is 1 to 3:1.

[0058] In some embodiments, in step (1), the reaction time of the hydrocarbon monolithium and the nitrogen-containing compound is 1 to 50 minutes. The reaction can be carried out at room temperature and pressure.

[0059] In some embodiments, the hydrocarbon monolithium and the nitrogen-containing compound can be dissolved in solvents respectively, and then the hydrocarbon monolithium solution and the nitrogen-containing compound solution are reacted. The concentrations of the hydrocarbon monolithium solution and the nitrogen-containing compound solution can be conventionally adjusted by a person skilled in the art. The solvent used includes, but is not limited to, one or a combination of pentane, hexane, heptane, octane, cyclopentane and cyclohexane.

[0060] 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%.

[0061] 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 functionalized initiator to styrene and butadiene based on the molecular weight of the double-end multi-functionalized 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 and tetramethylethylenediamine, 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 functionalized hydrocarbon monolithium can produce a polarization or solvation effect, reduce its degree of association, and increase the initiation reaction rate of a positive initiator such as n-butyl lithium.

[0062] In some embodiments, the molar ratio of the structure regulator to the hydrocarbon monolithium is 0.8 to 10.0:1.

[0063] In some embodiments, the structure regulator can be diluted with a 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 solvent used includes but is not limited to pentane, hexane, heptane, octane, cyclopentane and cyclohexane, etc., or a combination of several thereof.

[0064] In some embodiments, 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 and cyclohexane.

[0065] In some embodiments, the total amount of the butadiene and the styrene in the hydrocarbon solvent may have a concentration of 5% to 20% (mass concentration).

[0066] In some embodiments, step (2) specifically comprises: adding the butadiene, the styrene, and the structure regulator to a solvent, adding the functionalized initiator obtained in step (1) to carry out anionic polymerization when the temperature reaches 20 to 60° C., and continuing the reaction for 10 to 60 minutes after the temperature rises to a point where it does not continue to rise, 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, 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.

[0068] In some embodiments, the molar ratio of the dibasic acid anhydride to the hydrocarbon monolithium is 1 to 6:1.

[0069] 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 40-130° C. for 10-120 minutes, adding dibasic acid anhydride, reacting for another 10-120 minutes, and terminating the reaction with a terminator to obtain a system containing a terminal carboxyl functionalized polymer. The present invention does not impose any particular limitation on the reaction pressure of step (3).

[0070] In some embodiments, the molar ratio of the ethylene oxide to the hydrocarbon monolithium is 1 to 6:1.

[0071] 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.

[0072] In some embodiments, the terminator comprises an alcoholic acid solution. The acid comprises one or a combination of hydrochloric acid, sulfuric acid and nitric acid. The alcohol comprises one or a combination of methanol, ethanol and butanol. The molar ratio of the acid to the hydrocarbon monolithium is 1 to 10:1. The concentration of the acid in the alcoholic acid solution can be conventionally adjusted by a person skilled in the art.

[0073] 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.

[0074] In some embodiments, the molar ratio of the aminosiloxane to the hydrocarbon monolithium is 1 to 5:1.

[0075] In some embodiments, in step (4), the reaction temperature of the aminosiloxane and the carboxyl-terminated functionalized polymer is 40 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).

[0076] In some embodiments, the preparation method of the double-terminal multi-functionalized butadiene styrene polymer specifically comprises the following steps:

[0077] (1) Preparation of functionalized initiator

[0078] A protective gas (such as nitrogen) is passed into the reactor for replacement 3 to 5 times, and then a hydrocarbon monolithium and a nitrogen-containing compound are added into the reactor. After reacting for 1 to 50 minutes at normal temperature and pressure, a functionalized initiator is obtained. The reaction process is as follows:

[0079]

[0080] (2) Preparation of styrene-butadiene polymer active chains

[0081] A protective gas (such as nitrogen) is passed through the reactor for replacement 3 to 5 times, and then a hydrocarbon solvent, styrene, butadiene, and a solution of a structure regulator with a volume concentration of 10 to 20% are added to the reactor, stirring and heating are started, and heating is stopped when the temperature in the reactor reaches 20 to 60° C. The functionalized initiator obtained in step (1) is added to the reactor to carry out anionic polymerization reaction, and after the temperature rises to a temperature that does not continue to rise (i.e., the highest temperature), the reaction is continued for 10 to 60 minutes to obtain a system containing active chains of styrene-butadiene polymers. The reaction process is as follows:

[0082]

[0083] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0084] Add a tetrahydrofuran solution of ethylene oxide to the system containing the active chain of the styrene-butadiene polymer obtained in step (2), keep the temperature in the reactor at 40-130° C., react for 10-120 minutes, add a tetrahydrofuran solution of a dibasic acid anhydride, react for 10-120 minutes, and terminate the reaction with a terminator to obtain a system containing a styrene-butadiene polymer containing a terminal carboxyl group; the reaction process is as follows:

[0085]

[0086] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0087] Add aminosiloxane to the system containing the terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 40 to 130° C., react for 10 to 120 minutes, discharge the material, and obtain a double-terminal multifunctional styrene-butadiene polymer after rotary evaporation and drying. The reaction process is as follows:

[0088]

[0089] in, include:

[0090]

[0091] 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.

[0092] According to a specific embodiment of the present invention, the second aspect of the present invention provides a dual-terminal multi-functionalized butadiene styrene polymer, which is prepared by the above-mentioned preparation method of the dual-terminal multi-functionalized butadiene styrene polymer.

[0093] According to a specific embodiment of the present invention, preferably, the general formula of the double-terminal multi-functionalized butadiene styrene polymer is:

[0094]

[0095] in, include:

[0096]

[0097] 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 number average molecular weight of the dual-end multi-functionalized butadiene styrene 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 multi-functional butadiene styrene 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] According to a specific embodiment of the present invention, 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 to 150° C., the vulcanization pressure can be 10 to 15 MPa, and the vulcanization time can be 10 to 30 min.

[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%, Sane 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: 98%, 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 functionalized initiator

[0141] First, nitrogen was passed through a 200 mL tubular reactor for replacement 5 times, and then 1 mL of n-butyl lithium solution (1.6 mol / L) (0.25 mL of which will be used to remove moisture in the subsequent polymerization system and 0.75 mL of which will be used for the reaction in this step) and 1.35 mL of cyclopentane solution of cycloheximide (volume concentration 10%) were added to the reactor, and the reaction was carried out at room temperature and pressure for 5 minutes to obtain a functionalized 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. All the functionalized initiator obtained in step (1) was added to 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 30min to obtain a system containing active chains of styrene-butadiene polymer;

[0144] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[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 styrene-butadiene polymer containing terminal carboxyl groups;

[0146] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0147] To the system of styrene-butadiene polymer containing terminal carboxyl groups 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 multifunctional butadiene styrene polymer P-1 was obtained.

[0148] GPC measured the number average molecular weight of the polymer P-1 to be 151,200 and the molecular weight distribution to be 1.03. 1 The mass percentage of styrene units in the polymer P-1 measured by H-NMR was 20%.

[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 to the reactor. Stirring and heating were started. When the temperature in the reactor reached 40°C, heating was stopped. 1mL of n-butyllithium solution (1.6mol / L) was added to the reactor. 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 butadiene-styrene polymer D-1.

[0151] GPC measured the number average molecular weight of the polymer D-1 to be 150200 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%.

[0152] Example 2

[0153] (1) Preparation of functionalized initiator

[0154] First, nitrogen was passed into a 200 mL tubular reactor for replacement 4 times, and then 0.81 mL of n-butyl lithium solution (1.6 mol / L) (0.25 mL of which will be used to remove moisture in the subsequent polymerization system and 0.56 mL of which will be used for the reaction in this step) and 0.73 mL of cyclopentane solution of tetrahydropyrrole (volume concentration 10%) were added into the reactor, and the reaction was carried out at room temperature and pressure for 5 minutes to obtain a functionalized initiator;

[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 45°C. All the functionalized initiator obtained in step (1) was added to 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 10 minutes to obtain a system containing active chains of styrene-butadiene polymer;

[0157] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[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 3.21 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0159] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0160] To the system of styrene-butadiene polymer containing terminal carboxyl groups 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 multifunctional butadiene styrene polymer P-2 was obtained.

[0161] GPC measured the number average molecular weight of the polymer P-2 to be 205830 and the molecular weight distribution to be 1.08. 1 The mass percentage of styrene units in the polymer P-2 measured by H-NMR was 30%.

[0162] Comparative Example 2

[0163] The difference from Example 2 is that steps (1) and (3) are not performed, and in step (2), the initiator is replaced with 0.81 mL of n-butyl lithium solution (1.6 mol / L). 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 siloxane-functionalized butadiene-styrene polymer D-2.

[0164] GPC measured the number average molecular weight of the polymer D-2 to be 198,000 and the molecular weight distribution to be 1.42. 1 The mass percentage of styrene units in the polymer D-2 measured by H-NMR was 30.1%.

[0165] Example 3

[0166] (1) Preparation of functionalized initiator

[0167] First, nitrogen was passed into a 200 mL tubular reactor for replacement three times, and then 0.86 mL of tert-butyl lithium solution (1.7 mol / L) (0.27 mL of which will be used to remove moisture in the subsequent polymerization system and 0.59 mL of which will be used for the reaction in this step) and 1.3 mL of cyclopentane solution of phthalimide (volume concentration 10%) were added into the reactor, and the reaction was carried out at room temperature and pressure for 20 minutes to obtain a functionalized initiator;

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

[0169] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement 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. All the functionalized initiator obtained in step (1) was added to 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 40min to obtain a system containing active chains of styrene-butadiene polymer;

[0170] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[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 styrene-butadiene polymer containing terminal carboxyl groups;

[0172] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0173] To the system of styrene-butadiene polymer containing terminal carboxyl groups 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 multi-functional butadiene styrene polymer P-3 after rotary evaporation and drying.

[0174] GPC measured the number average molecular weight of the polymer P-3 to be 182,300 and the molecular weight distribution to be 1.05. 1 The mass percentage of styrene units in the polymer P-3 measured by H-NMR was 30.1%.

[0175] Comparative Example 3

[0176] The difference from Example 3 is that steps (3) and (4) are not performed, and after step (2) is completed, 5 mL of anhydrous ethanol is added to terminate the reaction to obtain terminal amine functionalized butadiene styrene polymer D-3.

[0177] GPC measured the number average molecular weight of the polymer D-3 to be 180,000 and the molecular weight distribution to be 1.06. 1 The mass percentage of styrene units in the polymer D-3 measured by H-NMR was 30.1%.

[0178] Example 4

[0179] (1) Preparation of functionalized initiator

[0180] First, nitrogen was passed through a 200 mL tubular reactor for replacement three times, and then 0.83 mL of tert-butyl lithium solution (1.7 mol / L) (0.27 mL of which will be used to remove moisture in the subsequent polymerization system and 0.56 mL of which will be used for the reaction in this step) and 1.23 mL of a cyclopentane solution of tetrahydropyridine (volume concentration 10%) were added to the reactor, and the reaction was carried out at room temperature and pressure for 25 minutes to obtain a functionalized initiator;

[0181] (2) Preparation of styrene-butadiene polymer active chains

[0182] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three 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 60°C. All the functionalized initiator obtained in step (1) was added to 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 20 minutes to obtain a system containing active chains of styrene-butadiene polymer;

[0183] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0184] 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 90° 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0185] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0186] Add 0.76 mL of 4-anilinotriethoxysilane to the system containing the terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 100° C., react for 30 minutes, discharge the material, and obtain a double-terminal multi-functional butadiene styrene polymer P-4 after rotary evaporation and drying.

[0187] GPC measured the number average molecular weight of the polymer P-4 to be 196,800 and the molecular weight distribution to be 1.03. 1 The mass percentage of styrene units in the polymer P-4 measured by H-NMR was 25.1%.

[0188] Comparative Example 4

[0189] The difference from Example 4 is that step (1) is not performed, and the initiator in step (2) is 0.83 mL of sec-butyl lithium solution (1.3 mol / L), to prepare siloxane-functionalized butadiene styrene polymer D-4.

[0190] GPC measured the number average molecular weight of the polymer D-4 to be 196,200 and the molecular weight distribution to be 1.03. 1 The mass percentage of styrene units in the polymer D-4 measured by H-NMR was 25.1%.

[0191] Example 5

[0192] (1) Preparation of functionalized initiator

[0193] First, nitrogen was passed into a 200 mL tubular reactor for replacement three times, and then 0.77 mL of sec-butyl lithium solution (1.3 mol / L) (0.22 mL of which will be used to remove moisture in the subsequent polymerization system and 0.55 mL of which will be used for the reaction in this step) and 1.3 mL of cyclopentane solution of morpholine (volume concentration 10%) were added into the reactor, and the reaction was carried out at room temperature and pressure for 30 minutes to obtain a functionalized initiator;

[0194] (2) Preparation of styrene-butadiene polymer active chains

[0195] 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 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 45°C. All the functionalized initiator obtained in step (1) was added to 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 35min to obtain a system containing active chains of styrene-butadiene polymer;

[0196] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0197] 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 130° 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0198] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0199] Add 0.5 mL of (anilinemethyl)methyldimethoxysilane to the system containing the terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 130°C, react for 10 minutes, discharge the material, and obtain a double-terminal multi-functional butadiene styrene polymer P-5 after rotary evaporation and drying.

[0200] GPC measured the number average molecular weight of the polymer P-5 to be 251100 and the molecular weight distribution to be 1.03. 1 The mass percentage of styrene units in the polymer P-5 measured by H-NMR was 30.1%.

[0201] Example 6

[0202] (1) Preparation of functionalized initiator

[0203] First, nitrogen was passed through a 200 mL tubular reactor for replacement three times, and then 1.02 mL of sec-butyl lithium solution (1.3 mol / L) (0.24 mL of which will be used to remove moisture in the subsequent polymerization system and 0.78 mL of which will be used for the reaction in this step) and 2 mL of cyclopentane solution of maleimide (volume concentration 10%) were added to the reactor, and the reaction was carried out at room temperature and pressure for 40 minutes to obtain a functionalized initiator;

[0204] (2) Preparation of styrene-butadiene polymer active chains

[0205] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement 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. All the functionalized initiator obtained in step (1) was added to 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 40min to obtain a system containing active chains of styrene-butadiene polymer;

[0206] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0207] 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0208] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0209] To the system of styrene-butadiene polymer containing terminal carboxyl groups 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 multi-functional butadiene styrene polymer P-6 after rotary evaporation and drying.

[0210] GPC measured the number average molecular weight of the polymer P-6 to be 176,000 and the molecular weight distribution to be 1.05. 1The mass percentage of styrene units in the polymer P-6 measured by H-NMR was 30.1%.

[0211] Comparative Example 5

[0212] 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 prepare a double-terminal multifunctional butadiene polymer D-5.

[0213] GPC measured the number average molecular weight of the polymer D-5 to be 185,200 and the molecular weight distribution to be 1.18. 1 The mass percentage of styrene units in the polymer D-5 measured by H-NMR was 30.1%.

[0214] This comparative example adopts the reaction of halogenated siloxane and styrene-butadiene polymer containing terminal carboxyl groups. In addition to the reaction of the halogenated group with the active site of the styrene-butadiene polymer containing terminal carboxyl groups, 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-5 of this comparative example wider, and the molecular weight and performance are difficult to control.

[0215] Example 7

[0216] (1) Preparation of functionalized initiator

[0217] First, nitrogen was passed into a 200 mL tubular reactor for replacement three times, and then 1.38 mL of n-butyl lithium solution (1.6 mol / L) (0.25 mL of which was used to remove moisture in the subsequent polymerization system and 1.13 mL was used for the reaction in this step) and 4.65 mL of cyclopentane solution of tetramethylpiperidone (volume concentration 10%) were added into the reactor, and the reaction was carried out at room temperature and pressure for 50 min to obtain a functionalized initiator;

[0218] (2) Preparation of styrene-butadiene polymer active chains

[0219] 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 1.5mL 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. All the functionalized initiator obtained in step (1) was added to 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 30min to obtain a system containing active chains of styrene-butadiene polymer;

[0220] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0221] 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0222] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0223] Add 0.7 mL of 3-aminopropyldimethylmethoxysilane to the system containing the 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 multifunctional butadiene styrene polymer P-7 after rotary evaporation and drying.

[0224] 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%.

[0225] Example 8

[0226] (1) Preparation of functionalized initiator

[0227] First, nitrogen was passed through a 200 mL tubular reactor for replacement three times, and then 0.55 mL of n-butyl lithium solution (1.6 mol / L) (0.25 mL of which will be used to remove moisture in the subsequent polymerization system and 0.30 mL of which will be used for the reaction in this step) and 1.3 mL of a cyclopentane solution of tetrahydropyridine (volume concentration 10%) were added to the reactor, and the reaction was carried out at room temperature and pressure for 45 minutes to obtain a functionalized initiator;

[0228] (2) Preparation of styrene-butadiene polymer active chains

[0229] First, a 3L stainless steel reactor with a jacket was replaced with nitrogen three 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 50°C. All the functionalized initiator obtained in step (1) was added to 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 50min to obtain a system containing active chains of styrene-butadiene polymer;

[0230] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0231] 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0232] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0233] To the system containing the 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 material was discharged after the reaction for 120 min. After rotary evaporation and drying, a double-terminal multifunctional butadiene styrene polymer P-8 was obtained.

[0234] 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%.

[0235] Example 9

[0236] (1) Preparation of functionalized initiator

[0237] First, nitrogen was passed into a 200 mL tubular reactor for replacement 5 times, and then 0.48 mL of sec-butyl lithium solution (1.3 mol / L) (0.25 mL of which will be used to remove moisture in the subsequent polymerization system and 0.23 mL of which will be used for the reaction in this step) and 0.95 mL of cyclopentane solution of cycloheximide (volume concentration 10%) were added into the reactor, and the reaction was carried out at room temperature and pressure for 50 minutes to obtain a functionalized initiator;

[0238] (2) Preparation of styrene-butadiene polymer active chains

[0239] First, nitrogen was passed through a 3L stainless steel reactor with a jacket for replacement three times, and then 1.1kg of cyclopentane, 18g of styrene, 162g of butadiene, and 4.2mL 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 45°C. All the functionalized initiator obtained in step (1) was added to 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;

[0240] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0241] 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0242] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0243] Add 0.35 mL of 3-aminopropyltriethoxysilane to the system containing the 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 multi-functional butadiene styrene polymer P-9 after rotary evaporation and drying.

[0244] GPC measured the number average molecular weight of the polymer P-9 to be 598,000 and the molecular weight distribution to be 1.04. 1 The mass percentage of styrene units in the polymer P-9 measured by H-NMR was 10.1%.

[0245] Example 10

[0246] (1) Preparation of functionalized initiator

[0247] First, nitrogen was passed into a 200 mL tubular reactor for replacement three times, and then 22.5 mL of sec-butyl lithium solution (1.3 mol / L) (0.3 mL of which will be used to remove moisture in the subsequent polymerization system and 22.2 mL of which will be used for the reaction in this step) and 35.4 mL of cyclopentane solution of tetrahydropyrrole (volume concentration 10%) were added into the reactor, and the reaction was carried out at room temperature and pressure for 15 minutes to obtain a functionalized initiator;

[0248] (2) Preparation of styrene-butadiene polymer active chains

[0249] 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. All the functionalized initiator obtained in step (1) was added to 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 55min to obtain a system containing active chains of styrene-butadiene polymer;

[0250] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0251] 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 55° C., react for 120 min, add 36 mL of a 1 mol / L tetrahydrofuran solution of succinic anhydride, react for 35 min, then add 36 mL of a 1 mol / L ethanol solution of hydrochloric acid to terminate the reaction, thereby obtaining a system containing a styrene-butadiene polymer containing terminal carboxyl groups;

[0252] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0253] Add 8.5 mL of 3-aminopropyldimethylmethoxysilane to the system containing the terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 65°C, react for 50 minutes, discharge the material, and obtain a double-terminal multi-functional butadiene styrene polymer P-10 after rotary evaporation and drying.

[0254] GPC measured the number average molecular weight of the polymer P-10 to be 5020 and the molecular weight distribution to be 1.14. 1 The mass percentage of styrene units in the polymer P-10 measured by H-NMR was 35.1%.

[0255] Embodiment 11

[0256] (1) Preparation of functionalized initiator

[0257] First, nitrogen was passed through a 200 mL tubular reactor for replacement 5 times, and then 1.2 mL of n-butyl lithium solution (1.6 mol / L) (0.25 mL of which will be used to remove moisture in the subsequent polymerization system and 0.95 mL of which will be used for the reaction in this step) and 2 mL of cyclopentane solution of maleimide (volume concentration 10%) were added to the reactor, and the reaction was carried out at room temperature and pressure for 15 minutes to obtain a functionalized initiator;

[0258] (2) Preparation of styrene-butadiene polymer active chains

[0259] 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 4.3mL (volume concentration 10%), diethylene glycol dimethyl ether cyclopentane solution 3.2mL (volume concentration 10%) were added to the reactor, stirring and heating were started, and heating was stopped when the temperature in the reactor reached 45°C, and all the functionalized initiator obtained in step (1) was added to the reactor. After the temperature rose 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;

[0260] (3) Preparation of styrene-butadiene polymers containing carboxyl groups at the end

[0261] 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 styrene-butadiene polymer containing terminal carboxyl groups;

[0262] (4) Preparation of double-terminal multifunctional styrene butadiene polymers

[0263] Add 1.5 mL of 4-anilinotriethoxysilane to the system containing the terminal carboxyl-containing styrene-butadiene polymer obtained in step (3), maintain the temperature in the reactor at 65°C, react for 70 minutes, discharge the material, and obtain a double-terminal multi-functional butadiene styrene polymer P-11 after rotary evaporation and drying.

[0264] GPC measured the number average molecular weight of the polymer P-11 to be 121220, and the molecular weight distribution was 1.05. 1 The mass percentage of styrene units in the polymer P-11 measured by H-NMR was 50%.

[0265] It should be noted that the amount of hydrocarbon monolithium added in the above-mentioned embodiments and comparative examples of the present invention may exceed the actual initiation amount, and the excess amount is mainly used to remove impurities in the polymerization reaction system. The amount of hydrocarbon monolithium required to break the impure water is explained in the embodiments. It is further explained that the ratio of the amount of other substances added to the amount of hydrocarbon monolithium added in the above-mentioned embodiments of the present invention is calculated according to the total amount of hydrocarbon monolithium minus the amount used to break the water.

[0266] Example 12

[0267] 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 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.

[0268] Comparative Example 6

[0269] 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.

[0270] Embodiment 13

[0271] 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.

[0272] Comparative Example 7

[0273] 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.

[0274] Embodiment 14

[0275] 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.

[0276] Comparative Example 8

[0277] Vulcanized rubber SD-3 was prepared according to the method of Example 14, which differed from Example 14 in that the polymer P-3 provided in Example 3 was replaced by the polymer D-3 provided in Comparative Example 3.

[0278] Embodiment 15

[0279] 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.

[0280] Comparative Example 9

[0281] Vulcanized rubber SD-4 was prepared according to the method of Example 15, which differed from Example 15 in that the polymer P-4 provided in Example 4 was replaced by the polymer D-4 provided in Comparative Example 4.

[0282] Example 16

[0283] 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.

[0284] Embodiment 17

[0285] 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 extender oil was 2 parts by weight of A1426.

[0286] Comparative Example 10

[0287] 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-5 provided in Comparative Example 5.

[0288] Embodiment 18

[0289] 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.

[0290] Embodiment 19

[0291] 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.

[0292] Embodiment 20

[0293] 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 16 parts by weight of A1820 and 4 parts by weight of A1426.

[0294] Embodiment 21

[0295] 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.

[0296] The physical properties and dynamic mechanical properties of the vulcanized rubbers provided in Examples 12 to 21 and Comparative Examples 6 to 10 are shown in Table 1.

[0297] Table 1

[0298]

[0299]

[0300] 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 multifunctional butadiene polymer provided by the present invention contains a group having good compatibility with carbon black / white carbon black, and the functional group content is relatively high, 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 double-ended multifunctional styrene butadiene polymer, comprising the following steps: (1) reacting a hydrocarbon monolithium with a nitrogen-containing compound to obtain a functionalized initiator; (2) using the functionalized 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 terminal carboxyl functionalized polymer; (4) Using aminosiloxane to react with the terminal carboxyl functionalized polymer to obtain the dual-terminal multi-functionalized butadiene styrene polymer.

2. The preparation method according to claim 1, wherein The general formula of the 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 these groups containing 1 to 20 carbon atoms; Preferably, the 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 nitrogen-containing compound includes one or a combination of cycloheximide, tetrahydropyrrole, morpholine, maleimide, tetramethyl piperidone, phthalimide and tetrahydropyridine.

4. The preparation method according to claim 1, wherein The molar ratio of the nitrogen-containing compound to the hydrocarbon monolithium is 1 to 3:1; Preferably, in step (1), the reaction time of the hydrocarbon monolithium and the nitrogen-containing compound is 1 to 50 minutes.

5. 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%.

6. 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 and tetramethylethylenediamine; Preferably, the molar ratio of the structure regulator to the hydrocarbon monolithium is 0.8-10.0:

1.

7. The preparation method according to claim 6, wherein: Step (2) specifically comprises: adding the butadiene, the styrene and the structure regulator into a solvent, adding the functionalized initiator obtained in step (1) to carry out anionic polymerization reaction when the temperature reaches 20 to 60° C., and continuing the reaction for 10 to 60 minutes after the temperature rises to a point where it does not continue to rise, to obtain a system containing active chains of styrene-butadiene polymer.

8. 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 hydrocarbon monolithium is 1 to 6:

1.

9. 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 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 terminal carboxyl functionalized polymer; Preferably, the molar ratio of the ethylene oxide to the hydrocarbon monolithium is 1 to 6:

1.

10. 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 hydrocarbon monolithium is 1 to 5:

1.

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

12. A dual-end multi-functionalized butadiene styrene polymer, which is prepared by the preparation method of the dual-end multi-functionalized butadiene styrene polymer according to any one of claims 1 to 11.

13. The double-terminal multifunctionalized butadiene styrene polymer according to claim 12, wherein: The general formula of the double-terminal multi-functionalized butadiene styrene polymer is: in, include: 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 number average molecular weight of the double-ended multi-functionalized butadiene styrene polymer is 5,000 to 600,000.

14. A rubber composition comprising: 100 parts by weight of the double-ended multifunctional styrene butadiene polymer according to claim 12 or 13, 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.

15. A vulcanized rubber prepared by mixing and vulcanizing the rubber composition according to claim 14.

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