Graft polymer of polybutadiene-styrene grafted with polybutadiene-isoprene, preparation method thereof, and vulcanized rubber

Abstract

The present invention relates to the field of graft polymers, and discloses a graft polymer of polybutadiene-styrene grafted with polybutadiene-isoprene, a preparation method thereof, and a vulcanized rubber. In the graft polymer, based on the total weight of the graft polymer, the content of styrene structural units is 5-15 weight %, the content of butadiene structural units is 35-55 weight %, and the content of isoprene structural units is 30-60 weight %; the number average molecular weight of the graft polymer is 100,000-1,500,000 g / mol, and the molecular weight distribution index is 3-6; based on the total amount of the isoprene structural units, the content of cis-1,4-structure is ≥95wt%. The preparation method is simple and easy to control, and the composition and molecular weight of the prepared polymer can be efficiently and accurately controlled at the same time.

Description

Technical Field

[0001] The present invention relates to the field of graft polymers, in particular to a graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene and a preparation method thereof, and a vulcanized rubber obtained from the graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene. Background Art

[0002] Chemically tailoring the branching and grafting structure of synthetic rubber is an effective method for controlling polymer structure and improving its processing properties. It can also improve compatibility when used with other rubbers. In recent years, research on branched diene rubbers has frequently appeared in related patents and literature reports.

[0003] CN1705687A discloses a synthetic branched polyisoprene and its preparation method. The method involves the polymerization of isoprene using a catalytic system. In the later stages of the polymerization reaction, the active chain ends react with additives such as SnCl4 to produce branched polyisoprene with a high cis-1,4 bond content and virtually no gel. This branched polyisoprene exhibits excellent mechanical properties. CN1884328A discloses the use of a molybdenum-based catalyst to produce a structurally controllable branched high-vinyl polybutadiene rubber. The properties, length, distribution, and degree of branching of the branches are controllable within a certain range, and the rubber exhibits excellent processing and physical and mechanical properties.

[0004] SIBR, or "integrated rubber," is a rubber synthesized by chemically copolymerizing three monomers: styrene, isoprene, and butadiene. It combines the excellent properties of several rubbers, including polybutadiene rubber, styrene-butadiene rubber, and polyisoprene rubber. Its molecular chain contains both flexible Bd and Ip component segments and rigid St component segments. The rigid segments enhance the rubber's wet skid resistance, while the flexible segments improve its wear resistance and reduce rolling resistance. This combination of rigidity and flexibility gives the rubber excellent overall performance. At the same time, the chemical bonding between the rigid and flexible segments solves the problem of the two phases not being able to merge, ensuring the stability of the rubber's properties. Early SIBRs were mostly prepared using anionic polymerization, and the products met the requirements of high-performance tire tread rubber. Compared to anionic polymerization, coordination polymerization offers greater regio- and stereoselectivity, making it easier to manipulate the polymer's sequence structure and stereoregularity, thereby adjusting the rubber's properties. For example, "Chain-Shuttling Polymerization at Two Different Scandium Sites: Regio- and Stereospecific "One-Pot" Block Copolymerization of Styrene, Isoprene, and Butadiene" (Hou Zhaomin et al., Angew. Chem. Int. Ed. 2011, 50, 12012-12015) discloses the use of a scandium-based rare earth cyclopentadiene catalyst to produce a St / Ip / Bd terpolymer (Sc-SIBR) containing syndiotactic polystyrene (sPS) segments, cis-1,4-Ip, and cis-1,4-Bd segments. The sPS segments have a syndiotacticity greater than 99%, and the contents of cis-1,4-Ip and cis-1,4-Bd structures in the conjugated diene components are both greater than 97%, exhibiting excellent stereoselectivity. However, Sc-SIBR has a multi-block structure with a regular structure and strong crystallinity, which makes the polymer have almost no rubber properties.

[0005] CN102786621B uses a neodymium catalyst to achieve a terpolymer with high styrene content and narrow distribution. However, compared with polybutadiene rubber (rare earth cis-1,4-butadiene rubber) and polyisoprene rubber (rare earth isoprene rubber) prepared using a rare earth catalytic system, its cis-1,4-structure content is significantly lower. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problem of low cis-1,4-structure content of isoprene segments in existing rubbers containing styrene, butadiene and isoprene, and to provide a graft polymer of polybutadiene-styrene grafted with polyisoprene, a preparation method thereof, and a vulcanized rubber.

[0007] To achieve the above objectives, the present invention provides, in a first aspect, a graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene, wherein, based on the total weight of the graft polymer, the content of styrene structural units in the graft polymer is 5-15% by weight, the content of butadiene structural units is 35-55% by weight, and the content of isoprene structural units is 30-60% by weight; the number average molecular weight of the graft polymer is 100,000-1.5 million g / mol, and the molecular weight distribution index is 3-6; and based on the total amount of the isoprene structural units, the content of cis-1,4-structure is ≥95% by weight.

[0008] A second aspect of the present invention provides a method for preparing a graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene, the method comprising the following steps:

[0009] (1) performing a first reaction on polybutadiene-isoprene, a polar additive, and a first alkyl lithium in a second organic solvent to obtain an active reaction solution 1;

[0010] (2) copolymerizing butadiene and styrene in a third organic solvent in the presence of a second alkyl lithium and an optional additive to obtain a reaction solution containing a butadiene-styrene copolymer; then slowly adding the reaction solution to a coupling agent in batches while maintaining sufficient mixing with the coupling agent to obtain an active reaction solution 2;

[0011] (3) The active reaction solution 1 and the active reaction solution 2 are subjected to a second reaction to obtain the graft polymer.

[0012] The third aspect of the present invention also provides a graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene prepared by the above method.

[0013] The fourth aspect of the present invention also provides a vulcanized rubber obtained from the above-mentioned graft polymer of polybutadiene-styrene grafted with polyisoprene.

[0014] Through the above technical solution, the preparation method of the present invention is simple and easy to control, and can simultaneously efficiently and accurately control the composition and number average molecular weight of the obtained grafted polymer. The grafted polymer has good structural regularity and excellent physical and mechanical properties.

[0015] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0016] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0017] A first aspect of the present invention provides a graft polymer of polybutadiene-styrene grafted onto polyisoprene, wherein, based on the total weight of the graft polymer, the content of styrene structural units in the graft polymer is 5-15% by weight, the content of butadiene structural units is 35-55% by weight, and the content of isoprene structural units is 30-60% by weight; the number average molecular weight of the graft polymer is 100,000-1.5 million g / mol, and the molecular weight distribution index is 3-6; and based on the total amount of the isoprene structural units, the content of cis-1,4-structure is ≥95% by weight.

[0018] In some embodiments of the present invention, preferably, the graft polymer has a number average molecular weight of 300,000-1.2 million g / mol and a molecular weight distribution index of 4-5.5.

[0019] In some embodiments of the present invention, preferably, based on the total amount of the isoprene structural units, the content of the cis-1,4-structure in the isoprene structural units is ≥ 96.5 wt %.

[0020] In some embodiments of the present invention, preferably, in the graft polymer, the content of styrene structural units is 6-14 wt%, the content of butadiene structural units is 37-53 wt%, and the content of isoprene structural units is 33-57 wt%;

[0021] The present invention can provide a graft polymer having the above-mentioned physical property parameters, which contains styrene structural units, butadiene structural units, and isoprene structural units, and the content of cis-1,4-structure in the isoprene structural units is high. The tensile strength of the vulcanized rubber finally prepared can reach above 20.1 MPa.

[0022] A second aspect of the present invention provides a method for preparing a graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene, the method comprising the following steps:

[0023] (1) performing a first reaction on polybutadiene-isoprene, a polar additive, and a first alkyl lithium in a second organic solvent to obtain an active reaction solution 1;

[0024] (2) copolymerizing butadiene and styrene in a third organic solvent in the presence of a second alkyl lithium and an optional additive to obtain a reaction solution containing a butadiene-styrene copolymer; then slowly adding the reaction solution to a coupling agent in batches while maintaining sufficient mixing with the coupling agent to obtain an active reaction solution 2;

[0025] (3) The active reaction solution 1 and the active reaction solution 2 are subjected to a second reaction to obtain the graft polymer.

[0026] In order to obtain the grafted polymer provided by the present invention, the grafted polymer can be obtained by using the conditions defined in the present invention in the preparation steps and the materials used.

[0027] In some embodiments of the present invention, preferably, in step (1), the polar additive is N,N,N',N'-tetramethylethylenediamine (TMEDA), which can reduce the association of alkyl lithium in the solvent and increase the reaction activity. To better achieve the grafted polymer of the present invention, preferably, the molar ratio of the polar additive to the first alkyl lithium is 1.5-3.5:1, preferably 2-3:1. Furthermore, the weight ratio of the polar additive to the polybutadiene-isoprene is 1:25-100.

[0028] In some embodiments of the present invention, the polybutadiene-isoprene has defined physical properties, which can better achieve the production of the graft polymer of the present invention. Preferably, in step (1), the polybutadiene-isoprene has a cis-1,4 structure content of ≥95 wt%, preferably ≥96.5 wt%, based on the total amount of isoprene structural units.

[0029] In some embodiments of the present invention, preferably, the number average molecular weight of the polybutadiene-isoprene is 60,000-1,000,000 g / mol, preferably 200,000-800,000 g / mol, and the molecular weight distribution index of the polybutadiene-isoprene is 3-6, preferably 3.5-5.

[0030] In some embodiments of the present invention, preferably, in the polybutadiene-isoprene, the weight ratio of the butadiene structural unit to the isoprene structural unit is 10:90-50:50, preferably 15:85-45:55.

[0031] In some embodiments of the present invention, preferably, in step (1), the first reaction is carried out in an inert atmosphere; the inert atmosphere refers to any gas or gas mixture that does not chemically react with the reactants and products, such as nitrogen and one or more of the gases in Group 0 of the periodic table, preferably nitrogen. Preferably, the conditions of the first reaction include: a first reaction temperature of room temperature to 70°C, a first reaction pressure of 0.1-0.4 MPa, and a first reaction time of 2-12 hours; preferably, the first reaction temperature is 40-60°C, the first reaction pressure is 0.2-0.3 MPa, and the first reaction time is 4-8 hours.

[0032] In some embodiments of the present invention, preferably, in step (2), the additive is tetrahydrofuran (abbreviated as THF) or N,N,N',N'-tetramethylethylenediamine. The additive can be used to adjust the polymerization environment.

[0033] In some embodiments of the present invention, the amount of the additive used is further limited to further facilitate the preparation of styrene-butadiene polymers with adjustable microstructures. Preferably, the molar ratio of the additive to butyl lithium is 0-200:1, preferably 1.5-150:1. More specifically, the ratio of THF:second alkyl lithium is 0-200:1, preferably 50-150:1; or the ratio of TMEDA:second alkyl lithium is 0-3.5:1, preferably 1.5-3.1.

[0034] In some embodiments of the present invention, step (2) involves copolymerization of butadiene and styrene. Preferably, the molar ratio of the total amount of butadiene and styrene to the second alkyl lithium is 100:0.3-3, preferably 100:0.5-2; further, the weight ratio of styrene to butadiene is 1:1-5, preferably 1:1.5-4.

[0035] In some embodiments of the present invention, preferably, in step (2), the coupling agent is dimethyldichlorosilane or dimethyltin dichloride; slowly adding the reaction solution to the coupling agent in batches can react the coupling agent with the Li at the end of the polymer in a molar ratio of 1:1 to generate the desired active reaction solution 2.

[0036] Preferably, the molar ratio of the coupling agent to the second alkyl lithium is 1-1.1:1, preferably 1.02-1.08:1.

[0037] In some embodiments of the present invention, preferably, in step (2), the copolymerization reaction is carried out in an inert atmosphere. As described above, the inert atmosphere refers to any gas or gas mixture that does not chemically react with the reactants and products, such as nitrogen and one or more of the gases in Group 0 of the periodic table, preferably nitrogen.

[0038] In some embodiments of the present invention, preferably, the copolymerization reaction temperature is 0°C-room temperature, the copolymerization reaction pressure is 0.1-0.4 MPa, and the copolymerization reaction time can be 1-3 hr; preferably, the copolymerization reaction temperature is 5-15°C, the copolymerization reaction pressure is 0.2-0.3 MPa, and the copolymerization reaction time is 1.5-2 hr.

[0039] In some embodiments of the present invention, preferably, the first alkyl lithium and the second alkyl lithium are each independently selected from one or more of methyl lithium, ethyl lithium, propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, and n-hexyl lithium, and preferably are each independently n-butyl lithium.

[0040] In some embodiments of the present invention, preferably, in step (3), the weight ratio of the polybutadiene-isoprene contained in the active reaction liquid 1 to the butadiene-styrene copolymer contained in the active reaction liquid 2 is 55-75:25-45. The weight of the polybutadiene-isoprene contained in the active reaction liquid 1 is based on the amount of polybutadiene-isoprene added in step (1). The weight of the butadiene-styrene copolymer contained in the active reaction liquid 2 can be determined by the following method: the weight of the active reaction liquid 2 is m1, and a small amount of liquid weighing m2 is taken from it and vacuum-dried at 50°C to a constant weight of m3. The weight of the polybutadiene-styrene in the active reaction liquid is m1*m3 / m2.

[0041] In some embodiments of the present invention, preferably, the molar ratio of the active Li contained in the active reaction liquid 1 to the active chlorine contained in the active reaction liquid 2 is 1.4-1:1, preferably 1.5-1:1. The molar amount of the active Li in the active reaction liquid 1 is the amount of the first alkyl lithium in step (1). The molar amount of the active chlorine in the active reaction liquid 2 is twice the amount of the coupling agent in step (2) minus the amount of the second alkyl lithium in step (2). The molar ratio of the active Li and the active chlorine is limited in the present invention, so that the active Li and the active chlorine react in a molar ratio of 1:1, which is conducive to obtaining the graft polymer of the present invention.

[0042] In some embodiments of the present invention, preferably, in step (3), the second reaction is carried out in an inert atmosphere. As described above, the inert atmosphere refers to any gas or gas mixture that does not chemically react with the reactants and products, such as nitrogen and one or more of the gases in Group 0 of the periodic table, preferably nitrogen. The second reaction temperature is room temperature to 70°C, the second reaction pressure is 0.1-0.4 MPa, and the second reaction time is 2-12 hours; preferably, the second reaction temperature is 40-60°C, the second reaction pressure is 0.2-0.3 MPa, and the second reaction time is 4-8 hours.

[0043] In some embodiments of the present invention, preferably, the polybutadiene-isoprene is prepared by the following method: subjecting a butadiene monomer and an isoprene monomer to a polymerization reaction in a first organic solvent in the presence of a rare earth catalyst; terminating the polymerization reaction with water or ethanol, and precipitating, washing, and drying the obtained polymerization product solution to obtain polybutadiene-isoprene.

[0044] In some embodiments of the present invention, preferably, the rare earth catalyst comprises a rare earth carboxylate compound, an alkyl aluminum compound, and a chloride;

[0045] Wherein, the rare earth carboxylate compound is C6-C 10 Neodymium carboxylate; the alkyl aluminum compound is at least one of the compounds represented by the general formula AlR3 and AlHR2, wherein R is a C1-C6 alkyl group; the chloride is AlR'2Cl, wherein R' is a C1-C6 alkyl group;

[0046] Preferably, the molar ratio of the alkyl aluminum compound calculated as aluminum to the rare earth carboxylate calculated as neodymium is 10-80; and the molar ratio of the chloride to the rare earth carboxylate calculated as neodymium is 2-4.

[0047] In some embodiments of the present invention, preferably, the preparation method of the rare earth catalyst is as follows: a ternary aging method is adopted in which any two of the three components of a rare earth carboxylate compound, an alkyl aluminum compound, and a chloride are first mixed and reacted, and then the third component is added to the mixed liquid to react; or a quaternary aging method is adopted in which a monomer is pre-mixed and reacted with any two of the three components of a rare earth carboxylate compound, an alkyl aluminum compound, and a chloride, and then the fourth component is reacted to obtain the desired catalyst aging liquid.

[0048] In some embodiments of the present invention, the inert atmosphere refers to any gas or gas mixture that does not chemically react with the reactants and products, such as nitrogen and one or more of the gases in Group 0 of the periodic table, preferably nitrogen. The method for maintaining the inert atmosphere can be to introduce any of the above-mentioned gases or gas mixtures that do not chemically react with the reactants and products into the reaction system. Preferably, the conditions for the polymerization reaction include: a molar ratio of butadiene monomer to isoprene monomer of 1:1-3, preferably 1:1.15-2.75; the molar amount of the rare earth catalyst calculated as neodymium is 0.015-0.08% of the total molar amount of the butadiene monomer and isoprene monomer; preferably, the polymerization reaction temperature is room temperature-70°C, the polymerization reaction pressure is 0.1-0.5 MPa, and the polymerization reaction time is 2-8 hours; preferably, the polymerization reaction temperature is 40-60°C, the polymerization reaction pressure is 0.3-0.4 MPa, and the polymerization reaction time is 3-6 hours.

[0049] The polymerization reaction process may be: adding the first organic solvent, butadiene monomer, isoprene monomer, and catalyst aging liquid in order according to a ratio into a reactor fully substituted with nitrogen; and stirring to carry out the polymerization reaction.

[0050] In some embodiments of the present invention, the first organic solvent, the second organic solvent, and the third organic solvent can be organic solvents commonly used in the art that can be used as reaction media, as long as they are liquid under the reaction conditions and neither participate in the polymerization reaction nor chemically interact with the polymer. Preferably, the first solvent, the second solvent, and the third solvent are C5-C 10 Saturated alkanes, C5-C 10 At least one of the cycloalkanes. Generally, the first organic solvent, the second organic solvent, and the third organic solvent can be independently selected from one or more of pentane and its isomers (e.g., n-pentane and isopentane), hexane and its isomers (e.g., n-hexane), heptane and its isomers (e.g., n-heptane), octane and its isomers (e.g., n-octane), cyclohexane, and raffinate. Preferably, at least one of hexane, methylcyclopentane, 2-methylpentane, 3-methylpentane, cyclohexane, heptane, and octane is selected.

[0051] The amounts of the first organic solvent, the second organic solvent, and the third organic solvent can be conventionally selected in the art and are not particularly limited. Generally, the amount of the first organic solvent can be such that the total concentration of butadiene and isoprene is 1-2 mol / L, and the amount of the second organic solvent can be such that the concentration of polybutadiene-isoprene is 1×10 -4 -4×10 -4 mol / L, and the amount of the third organic solvent used can make the total concentration of butadiene and styrene be 1-2 mol / L, which not only allows the polymerization reaction to proceed smoothly, but also can achieve higher production efficiency.

[0052] In some embodiments of the present invention, after the second reaction is completed, the method for adding a terminator-antioxidant can be used to deactivate the active polymer chain, thereby terminating the above-mentioned reaction and preventing aging and deterioration during the preparation and storage of subsequent raw rubber. The use of the terminator-antioxidant can be used in the form of a terminator solution containing a certain mass concentration of the antioxidant. The antioxidant is, for example, 2,6-di-tert-butyl-p-methylphenol (abbreviated as 264), 2-sec-butyl-4,6-dinitrophenol, 2,4-bis(n-octylthiomethylene)-6-methylphenol, tris-nonylated phenyl phosphite, tetrakis[β-(3',5')-di-tert-butyl-4'-hydroxyphenyl] propionic acid pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl alcohol ester and 2,2'-methylene bis-(4-methyl-6-tert-butylphenol), and the mass concentration of the antioxidant can be at least one of 1-5 weight %. The type of the terminator is not particularly limited, as long as the terminator can inactivate the active chain of the polymer. Generally, the terminator can be water, C1-C6 aliphatic alcohol, C4-C 12 At least one of an aliphatic carboxylic acid and an aromatic polyol. The aromatic polyol is a compound in which at least two hydrogen atoms on a benzene ring are replaced by hydroxyl groups. Preferably, the terminator is at least one of water, methanol, ethanol, and isopropanol.

[0053] The present invention has no particular limitation on the amount of the terminator, as long as the amount of the terminator can inactivate the active species in the polymer product, which will not be elaborated herein.

[0054] The present invention has no particular limitation on the polymerization device for the polymerization reaction, and it can be any conventional device in the art, such as a polymerization tube or a batch reactor.

[0055] The third aspect of the present invention provides a graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene obtained by the above preparation method. The characteristics of the graft polymer are as described above and will not be repeated here.

[0056] The fourth aspect of the present invention provides a vulcanized rubber obtained from the above-mentioned graft polymer of polybutadiene-styrene grafted with polybutadiene-isoprene.

[0057] The vulcanized rubber can be prepared by adding a vulcanizing agent to the grafted polymer and performing a vulcanization process.

[0058] The present invention does not particularly limit the type and amount of the vulcanizing agent, nor the specific operation and conditions of the vulcanization, and can be appropriately selected based on the specific application of the vulcanized rubber and conventional knowledge in the art. For example, when the vulcanized rubber is used in the field of automobile tires, the total amount of the vulcanizing agent can be 0.5 parts by weight, preferably 0.6-2.5 parts by weight, relative to 100 parts by weight of the grafted polymer. The vulcanizing agent can be selected from one or more of sulfur, selenium, tellurium, benzoyl peroxide, ethyl carbamate, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0059] The vulcanization process may also be carried out in the presence of at least one vulcanization accelerator. The vulcanization accelerator may be any of various vulcanization accelerators commonly used in the art, for example, at least one selected from zinc oxide, magnesium oxide, and stearic acid. The amount of the vulcanization accelerator used may be appropriately selected depending on the type of vulcanizing agent, and will not be further described herein.

[0060] In the present invention, the vulcanized rubber may further include various commonly used additives, such as antioxidants and fillers, depending on the specific application area, to improve the properties of the vulcanized rubber or impart various properties or functions to the vulcanized rubber. For example, an antioxidant may be added to impart good aging resistance to the resulting vulcanized rubber. The types and amounts of the additives may be conventionally selected in the art and will not be further elaborated herein.

[0061] The present invention will be described in detail below through examples.

[0062] In the following examples and comparative examples, the parameters involved were measured by the following methods:

[0063] The number average molecular weight (Mn) and molecular weight distribution index (PDI = Mw / Mn) of polybutadiene-isoprene and polybutadiene-styrene grafted polybutadiene-isoprene graft polymers were characterized by gel permeation chromatography (GPC) (Waters). A calibration curve was established using polystyrene standards.

[0064] The microstructure, content and composition of the polymer were characterized by a German Bruker 400 MHz nuclear magnetic resonance spectrometer using deuterated chloroform as the solvent.

[0065] Examples 1-8 are used to illustrate the grafted polymers and their preparation methods provided by the present invention.

[0066] Example 1

[0067] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0068] In a reactor that had been evacuated and replaced with high-purity nitrogen three times, 2300 mL of n-hexane, 108 g of butadiene (2.0 mol, abbreviated as Bd) and 204 g of isoprene (3.0 mol, abbreviated as Ip) were added respectively, and the catalyst aging solution (Nd / Bd + Ip = 3.0 × 10 -4 (molar ratio) and then reacted at 50°C for 5 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 302 g of polybutadiene-isoprene.

[0069] GPC measured the number average molecular weight of the polybutadiene-isoprene at 517,000 g / mol, with a molecular weight distribution index of 4.03. NMR analysis revealed a butadiene content of 36.2 wt% and an isoprene content of 63.8 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-form was 97.4 wt%.

[0070] To a reaction flask that had been vacuum-evacuated, heated, and replaced with high-purity nitrogen three times, 500 mL of n-hexane and 30 g of the aforementioned polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.42 g of TMEDA (3.62 mmol) and 0.90 mL of a 1.6 mol / L nBuLi (1.44 mmol) hexane solution were added in sequence. The first reaction was carried out at 60°C for 5 hours to obtain active reaction solution 1-1.

[0071] To a reaction tube that had been vacuum-evacuated, heated, and replaced with high-purity nitrogen three times, 100 mL of n-hexane, 2.5 g of styrene (24.0 mmol), and 7.5 g of butadiene (138.9 mmol) were added in sequence. After mixing, 0.32 g of TMEDA (2.76 mmol) and 0.70 mL of a 1.6 mol / L nBuLi (1.12 mmol) hexane solution were added, and copolymerization was carried out at 10°C for 2 hours. Then, 0.15 g of dimethyldichlorosilane (1.16 mmol) was added to the reaction solution to obtain active reaction solution 2-1.

[0072] Under nitrogen, active reaction solution 2-1 was added to active reaction solution 1-1. A second reaction was carried out at 60°C for 6 hours. After completion, the reaction was terminated with an ethanol solution containing 1 wt% 2,6-di-tert-butyl-p-methylphenol. The resulting polymer solution was precipitated, washed, and dried to yield 38.2 g of a grafted polymer, designated JZ-1.

[0073] GPC measured the number average molecular weight of the grafted polymer to be 692,000 g / mol, and the molecular weight distribution index to be 4.66.

[0074] Structural analysis of the grafted polymer revealed that, based on 100% by weight of the grafted polymer, the styrene content was 6.4% by weight, the butadiene content was 42.4% by weight, and the isoprene content was 51.2% by weight. Furthermore, based on 100% by weight of the isoprene structural units, the cis-1,4-structure content was 97.3% by weight.

[0075] Example 2

[0076] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0077] In the reactor which had been vacuum evacuated and replaced with high-purity nitrogen three times, 2700 mL of n-hexane, 108 g of butadiene (2.0 mol) and 350 g of isoprene (5.1 mol) were added respectively, and the catalyst aging solution Nd / Bd+Ip=5.0×10 -4 (molar ratio) and then reacted at 50°C for 5 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 354g of polybutadiene-isoprene.

[0078] GPC measured the number average molecular weight of the polybutadiene-isoprene at 330,000 g / mol, with a molecular weight distribution index of 4.21. NMR analysis revealed a butadiene content of 26.1 wt% and an isoprene content of 73.9 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-form was 97.2 wt%.

[0079] To a reaction flask that had been vacuum-evacuated, heated, and replaced with high-purity nitrogen three times, 420 mL of n-hexane and 25 g of polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.46 g of TMEDA (3.97 mmol) and 1.00 mL of a 1.6 mol / L nBuLi (1.60 mmol) hexane solution were added sequentially. The first reaction was carried out at 60°C for 6 hours to obtain active reaction solution 1-2.

[0080] To a reaction tube that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 100 mL of n-hexane, 2.8 g of styrene (26.9 mmol), and 7.2 g of butadiene (133.3 mmol) were added in sequence. After mixing, 0.24 g of TMEDA (2.06 mmol) and 0.80 mL of a 1.6 mol / L nBuLi (1.28 mmol) hexane solution were added, and copolymerization was carried out at 10°C for 2 hours. Then, 0.17 g of dimethyldichlorosilane (1.32 mmol) was added to the reaction solution to obtain active reaction solution 2-2.

[0081] Under nitrogen, active reaction solution 2-2 was added to active reaction solution 1-2. A second reaction was carried out at 50°C for 7 hours. After completion, the reaction was terminated with an ethanol solution containing 1 wt% 2,6-di-tert-butyl-p-methylphenol. The resulting polymer solution was precipitated, washed, and dried to yield 32.2 g of a grafted polymer, designated JZ-2.

[0082] GPC measured the number average molecular weight of the grafted polymer to be 458,000 g / mol, and the molecular weight distribution index to be 4.38.

[0083] The results of the graft polymer structure analysis are as follows: based on the weight of the graft polymer as 100%, the styrene content was 8.2 wt%, the butadiene content was 39.6 wt%, and the isoprene content was 52.2 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-structure content was 97.0 wt%.

[0084] Example 3

[0085] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0086] In the reactor which had been vacuum-evacuated and replaced with high-purity nitrogen three times, 2500 mL of n-hexane, 135 g of butadiene (2.5 mol) and 204 g of isoprene (3.0 mol) were added respectively, and the catalyst aging solution Nd / Bd+Ip=1.8×10 -4 (molar ratio) and then reacted at 50°C for 6 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 319 g of polybutadiene-isoprene.

[0087] GPC measured the number average molecular weight of the polybutadiene-isoprene at 718,000 g / mol, with a molecular weight distribution index of 3.83. NMR analysis revealed a butadiene content of 41.7% by weight and an isoprene content of 59.3% by weight. Based on the weight of the isoprene structural units as 100%, the cis-1,4-form was 97.5% by weight.

[0088] To a reaction flask that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 340 mL of n-hexane and 20 g of the aforementioned polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.56 g of TMEDA (4.83 mmol) and 1.30 mL of a 1.6 mol / L nBuLi (2.08 mmol) hexane solution were added in sequence. The first reaction was carried out at 60°C for 5 hours to obtain active reaction solution 1-3.

[0089] To a reaction tube that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 100 mL of n-hexane, 3.0 g of styrene (28.8 mmol), and 7.0 g of butadiene (129.6 mmol) were added in sequence. After mixing, 11.52 g of THF (160 mmol) and 1.00 mL of a 1.6 mol / L nBuLi (1.60 mmol) hexane solution were added, and copolymerization was carried out at 5°C for 2 hours. Then, 0.36 g of dimethyltin dichloride (1.64 mmol) was added to the reaction solution to obtain active reaction solution 2-3.

[0090] Under nitrogen, active reaction solution 2-3 was added to active reaction solution 1-3. A second reaction was carried out at 60°C for 6 hours. After completion, the reaction was terminated with an ethanol solution containing 1 wt% 2,6-di-tert-butyl-p-methylphenol. The resulting polymer solution was precipitated, washed, and dried to yield 27.2 g of a grafted polymer, designated JZ-3.

[0091] GPC measured the number average molecular weight of the grafted polymer to be 1.064 million g / mol, and the molecular weight distribution index to be 4.49.

[0092] The results of the graft polymer structure analysis are as follows: based on the weight of the graft polymer as 100%, the styrene content was 10.8 wt%, the butadiene content was 48.8 wt%, and the isoprene content was 40.4 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-structure content was 97.4 wt%.

[0093] Example 4

[0094] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0095] In the reactor which had been vacuum-evacuated and replaced with high-purity nitrogen three times, 2000 mL of n-hexane, 64.8 g of butadiene (1.2 mol) and 350 g of isoprene (5.1 mol) were added respectively, and the catalyst aging solution Nd / Bd+Ip=7.5×10 -4 (molar ratio) and then reacted at 50°C for 6 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 255g of polybutadiene-isoprene.

[0096] GPC measured the number average molecular weight of the polybutadiene-isoprene at 224,000 g / mol, with a molecular weight distribution index of 4.52. NMR analysis revealed a butadiene content of 16.8 wt% and an isoprene content of 83.2 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-form was 97.1 wt%.

[0097] To a reaction flask that had been vacuum-evacuated, heated, and replaced with high-purity nitrogen three times, 310 mL of n-hexane and 18 g of the aforementioned polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.56 g of TMEDA (4.83 mmol) and 1.90 mL of a 1.6 mol / L nBuLi (3.04 mmol) hexane solution were added in sequence. The first reaction was carried out at 60°C for 5 hours to obtain active reaction solutions 1-4.

[0098] To a reaction tube that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 120 mL of n-hexane, 2.4 g of styrene (23.1 mmol), and 9.6 g of butadiene (177.8 mmol) were added in sequence. After mixing, 0.49 g of TMEDA (4.22 mmol) and 1.50 mL of a 1.6 mol / L nBuLi (2.40 mmol) hexane solution were added, and copolymerization was carried out at 5°C for 2 hours. Then, 0.32 g of dimethyldichlorosilane (2.48 mmol) was added to the reaction solution to obtain active reaction solution 2-4.

[0099] Under nitrogen, active reaction solution 2-4 was added to active reaction solution 1-4. A second reaction was carried out at 60°C for 6 hours. After completion of the reaction, the reaction was terminated with an ethanol solution containing 2 wt% 2,6-di-tert-butyl-p-methylphenol. The resulting polymer solution was precipitated, washed, and dried to yield 27.1 g of a grafted polymer, designated JZ-4.

[0100] GPC measured the number average molecular weight of the grafted polymer to be 353,000 g / mol, and the molecular weight distribution index to be 5.42.

[0101] The results of the graft polymer structure analysis are as follows: based on the weight of the graft polymer as 100%, the styrene content was 8.6 wt%, the butadiene content was 47.1 wt%, and the isoprene content was 44.3 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-structure content was 96.8 wt%.

[0102] Example 5

[0103] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0104] In the reactor which had been vacuum-evacuated and replaced with high-purity nitrogen three times, 2000 mL of n-hexane, 108 g of butadiene (2 mol) and 170 g of isoprene (2.5 mol) were added respectively, and the catalyst aging solution Nd / Bd+Ip=3.0×10 -4 (molar ratio) and then reacted at 50°C for 5 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 250g of polybutadiene-isoprene.

[0105] GPC measured the number average molecular weight of the polybutadiene-isoprene at 524,000 g / mol, with a molecular weight distribution index of 4.15. NMR analysis revealed a butadiene content of 39.9 wt% and an isoprene content of 60.1 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-form was 97.3 wt%.

[0106] To a reaction flask that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 500 mL of n-hexane and 30 g of the aforementioned polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.98 g of TMEDA (8.45 mmol) and 2.20 mL of a 1.6 mol / L nBuLi (3.52 mmol) hexane solution were added in sequence. The first reaction was carried out at 60°C for 5 hours to obtain active reaction solutions 1-5.

[0107] To a reaction tube that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 180 mL of n-hexane, 5.4 g of styrene (51.8 mmol), and 12.6 g of butadiene (233.3 mmol) were added in sequence. After mixing, 20.74 g of THF (288 mmol) and 1.80 mL of a 1.6 mol / L nBuLi (2.88 mmol) hexane solution were added, and copolymerization was carried out at 5°C for 2 hours. Then, 0.65 g of dimethyltin dichloride (2.95 mmol) was added to the reaction solution to obtain active reaction solution 2-5.

[0108] Under nitrogen, active reaction solution 2-5 was added to active reaction solution 1-5. A second reaction was carried out at 50°C for 6 hours. After completion, the reaction was terminated with an ethanol solution containing 1 wt% 2,6-di-tert-butyl-p-methylphenol. The resulting polymer solution was precipitated, washed, and dried to yield 44.8 g of a grafted polymer, designated JZ-5.

[0109] GPC measured the number average molecular weight of the grafted polymer to be 815,000 g / mol, and the molecular weight distribution index to be 4.90.

[0110] The results of the graft polymer structure analysis are as follows: based on the weight of the graft polymer as 100%, the styrene content was 11.7 wt%, the butadiene content was 49.0 wt%, and the isoprene content was 39.3 wt%. Based on the weight of the isoprene structural unit as 100%, the cis-1,4-structure content was 97.0 wt%.

[0111] Example 6

[0112] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0113] In the reactor which had been vacuum-evacuated and replaced with high-purity nitrogen three times, 1900 mL of n-hexane, 81 g of butadiene (1.5 mol) and 350 g of isoprene (5.1 mol) were added respectively, and the catalyst aging solution Nd / Bd+Ip=7.5×10 -4 (molar ratio) and then reacted at 50°C for 6 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 236 g of polybutadiene-isoprene.

[0114] GPC measured the number average molecular weight of the polybutadiene-isoprene at 236,000 g / mol, with a molecular weight distribution index of 4.64. NMR analysis revealed a butadiene content of 20.0 wt% and an isoprene content of 80.0 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-form was 97.2 wt%.

[0115] To a reaction flask that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 310 mL of n-hexane and 18 g of the aforementioned polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.53 g of TMEDA (4.58 mmol) and 1.1 mL of a 1.6 mol / L nBuLi (1.76 mmol) hexane solution were added in sequence. The first reaction was carried out at 60°C for 5 hours to obtain active reaction solution 1-6.

[0116] To a reaction tube that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 120 mL of n-hexane, 3.0 g of styrene (28.8 mmol), and 9.0 g of butadiene (166.7 mmol) were added in sequence. After mixing, 0.38 g of TMEDA (3.31 mmol) and 0.84 mL of a 1.6 mol / L nBuLi (1.34 mmol) hexane solution were added, and copolymerization was carried out at 10°C for 2 hours. Then, 0.18 g of dimethyldichlorosilane (1.39 mmol) was added to the reaction solution to obtain active reaction solution 2-6.

[0117] Under nitrogen, active reaction solution 2-6 was added to active reaction solution 1-6. A second reaction was carried out at 60°C for 6 hours. After completion of the reaction, the reaction was terminated with an ethanol solution containing 1 wt% 2,6-di-tert-butyl-p-methylphenol. The resulting polymer solution was precipitated, washed, and dried to yield 28.2 g of a grafted polymer, designated JZ-6.

[0118] GPC measured the number average molecular weight of the grafted polymer to be 385,000 g / mol, and the molecular weight distribution index to be 5.13.

[0119] The product structure analysis results are as follows: based on the weight of the styrene-butadiene grafted polybutadiene-isoprene as 100%, the styrene content is 11.0 wt%, the butadiene content is 47.9 wt%, and the isoprene content is 41.1 wt%. Based on the weight of the polyisoprene as 100%, the cis-1,4-structure content is 96.9 wt%.

[0120] Example 7

[0121] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0122] In the reactor which had been vacuum-evacuated and replaced with high-purity nitrogen three times, 2200 mL of n-hexane, 81 g of butadiene (1.5 mol) and 350 g of isoprene (5.1 mol) were added respectively, and the catalyst aging solution Nd / Bd+Ip=1.8×10 -4 (molar ratio) and then reacted at 50°C for 6 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 280g of polybutadiene-isoprene.

[0123] GPC measured the number average molecular weight of the polybutadiene-isoprene at 735,000 g / mol, with a molecular weight distribution index of 3.92. NMR analysis revealed a butadiene content of 21.3 wt% and an isoprene content of 78.7 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-structure content was 97.5 wt%.

[0124] To a reaction flask that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 500 mL of n-hexane and 30 g of the aforementioned polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.37 g of TMEDA (3.20 mmol) and 0.85 mL of a 1.6 mol / L nBuLi (1.36 mmol) hexane solution were added in sequence. The first reaction was carried out at 60°C for 5 hours to obtain active reaction solution 1-7.

[0125] To a reaction tube that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 100 mL of n-hexane, 2.5 g of styrene (24.0 mmol), and 7.5 g of butadiene (138.9 mmol) were added in sequence. After mixing, 0.32 g of TMEDA (2.76 mmol) and 0.70 mL of a 1.6 mol / L nBuLi (1.12 mmol) hexane solution were added, and copolymerization was carried out at 10°C for 2 hours. Then, 0.15 g of dimethyldichlorosilane (1.16 mmol) was added to the reaction solution to obtain active reaction solution 2-7.

[0126] Under nitrogen, active reaction solution 2-7 was added to active reaction solution 1-7. A second reaction was carried out at 60°C for 6 hours. After completion, the reaction was terminated with an ethanol solution containing 1 wt% 2,6-di-tert-butyl-p-methylphenol. The resulting polymer solution was precipitated, washed, and dried to yield 36.8 g of a grafted polymer, designated JZ-7.

[0127] GPC measured the number average molecular weight of the grafted polymer to be 972,000 g / mol, and the molecular weight distribution index to be 4.21.

[0128] The results of the graft polymer structure analysis are as follows: based on the weight of the graft polymer as 100%, the styrene content was 6.6 wt%, the butadiene content was 37.5 wt%, and the isoprene content was 55.9 wt%. Based on the weight of the isoprene structural unit as 100%, the cis-1,4-structure content was 97.4 wt%.

[0129] Example 8

[0130] Under nitrogen protection, neodymium neodecanoate (abbreviated as: Nd) and triisobutylaluminum (abbreviated as: Al) were added to the catalyst preparation device, Al / Nd = 30 (molar ratio), and aged at 30°C for 0.5 hours. Then, diethylaluminum monochloride (abbreviated as: Cl) was added, Cl / Nd = 2.5 (molar ratio), and aged at 30°C for 1 hour.

[0131] In the reactor which had been vacuum-evacuated and replaced with high-purity nitrogen three times, 2500 mL of n-hexane, 135 g of butadiene (2.5 mol) and 204 g of isoprene (3.0 mol) were added respectively, and the catalyst aging solution Nd / Bd+Ip=1.8×10 -4 (molar ratio) and then reacted at 50°C for 6 hours. After the polymerization was completed, the reaction was terminated with ethanol. The polymer solution was precipitated, washed, and dried to obtain 319 g of polybutadiene-isoprene.

[0132] GPC measured the number average molecular weight of the polybutadiene-isoprene at 718,000 g / mol, with a molecular weight distribution index of 3.83. NMR analysis revealed a butadiene content of 41.1% by weight and an isoprene content of 58.9% by weight. Based on the weight of the isoprene structural units as 100%, the cis-1,4-form was 97.5% by weight.

[0133] To a reaction flask that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 340 mL of n-hexane and 20 g of the aforementioned polybutadiene-isoprene were added, respectively, and stirred to dissolve the polybutadiene-isoprene. Then, 0.56 g of TMEDA (4.83 mmol) and 1.30 mL of a 1.6 mol / L nBuLi (2.08 mmol) hexane solution were added in sequence. The first reaction was carried out at 60°C for 5 hours to obtain active reaction solution 1-8.

[0134] To a reaction tube that had been vacuum-evacuated, heated, baked, and replaced with high-purity nitrogen three times, 150 mL of n-hexane, 4.5 g of styrene (43.3 mmol), and 10.5 g of butadiene (194.4 mmol) were added in sequence. After mixing, 0.48 g of TMEDA (4.14 mmol) and 1.05 mL of a 1.6 mol / L nBuLi (1.68 mmol) hexane solution were added, and copolymerization was carried out at 10°C for 2 hours. Then, 0.22 g of dimethyldichlorosilane (1.72 mmol) was added to the reaction solution to obtain active reaction solution 2-8.

[0135] Under nitrogen, active reaction solution 2-8 was added to active reaction solution 1-8. A second reaction was carried out at 60°C for 6 hours. After completion, the reaction was terminated with an ethanol solution containing 1 wt% 2,6-di-tert-butyl-p-methylphenol. The polymer solution was precipitated, washed, and dried to obtain 32.2 g of a grafted polymer, designated JZ-8.

[0136] GPC measured the number average molecular weight of the grafted polymer to be 1.193 million and the molecular weight distribution index to be 4.42.

[0137] The results of the graft polymer structure analysis are as follows: based on the weight of the graft polymer as 100%, the styrene content was 13.5 wt%, the butadiene content was 52.2 wt%, and the isoprene content was 34.3 wt%. Based on the weight of the isoprene structural units as 100%, the cis-1,4-structure content was 97.4 wt%.

[0138] Comparative Example 1

[0139] Styrene-isoprene-butadiene terpolymer rubber, designated DJZ-1, was synthesized with reference to "Properties of Integrated Rubbers with Different Sequence Distributions" (Synthetic Rubber Industry, 2014, 4, 280-283). It has a number average molecular weight of 205,000 g / mol, a molecular weight distribution index of 2.08, and an isoprene structural unit content of 40.2 wt%.

[0140] Test Case

[0141] JZ-1 to JZ-8 obtained in Examples 1 to 8 and DJZ-1 in Comparative Example 1 were prepared into vulcanized rubbers.

[0142] An open mill is used for mixing at a roller temperature of 50±5° C., and then vulcanization is performed; the vulcanization conditions include: a temperature of 145° C. and a vulcanization time of 20 minutes.

[0143] The basic vulcanization formula is: 100 phr raw rubber; 50 phr carbon black; 1.75 phr sulfur; 1 phr accelerator NS; 1 phr stearic acid; 3 phr zinc oxide; and 1 phr antioxidant D. The raw rubbers are JZ-1 to JZ-8 and DJZ-1. phr is parts by weight.

[0144] The mechanical properties of the obtained vulcanized rubber were tested according to the method specified in GB / T528-1998. The physical and mechanical properties of the vulcanized rubber are listed in Table 1.

[0145] Table 1

[0146]

[0147] The results of the above examples show that the vulcanized rubbers prepared using the graft polymers JZ-1 to JZ-8 prepared in Examples 1-8 as base rubber exhibited higher tensile strength than the vulcanized rubber prepared using the graft polymer DJZ-1 of Comparative Example 1 as base rubber. A comparison of JZ-1 to JZ-7 also shows that the tensile strength increases with increasing isoprene structural unit content.

[0148] Comparing JZ-8 and DJZ-1, the isoprene content is 34.3wt% and 40.2wt%, respectively. The corresponding tensile strengths of the vulcanized rubbers produced from these raw rubbers are 20.1MPa and 19.5MPa, respectively. This indicates that increasing the cis-1,4-structure content in the isoprene units increases the tensile strength.

[0149] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

[0150] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0151] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene, characterized in that: Based on the total weight of the graft polymer, the content of the styrene structural unit in the graft polymer is 5-15% by weight, the content of the butadiene structural unit is 35-55% by weight, and the content of the isoprene structural unit is 30-60% by weight; The graft polymer has a number average molecular weight of 100,000-1.5 million g / mol and a molecular weight distribution index of 3-6; based on the total amount of the isoprene structural units, the content of the cis-1,4-structure is greater than or equal to 95 wt %.

2. The graft polymer according to claim 1, wherein The graft polymer has a number average molecular weight of 300,000-1.2 million g / mol and a molecular weight distribution index of 4-5.5; and / or, based on the total amount of the isoprene structural units, the content of cis-1,4-structure in the isoprene structural units is ≥96.5 wt %; And / or, in the graft polymer, the content of styrene structural units is 6-14 wt %, the content of butadiene structural units is 37-53 wt %, and the content of isoprene structural units is 33-57 wt %.

3. A method for preparing a graft polymer of polybutadiene-styrene grafted onto polybutadiene-isoprene according to claim 1 or 2, the method comprising the following steps: (1) performing a first reaction on polybutadiene-isoprene, a polar additive, and a first alkyl lithium in a second organic solvent to obtain an active reaction solution 1; (2) in the presence of a second alkyl lithium and an optional additive, copolymerizing butadiene and styrene in a third organic solvent to obtain a reaction solution containing a butadiene-styrene copolymer; then slowly adding the reaction solution to a coupling agent in batches while maintaining sufficient mixing with the coupling agent to obtain an active reaction solution 2; (3) subjecting the active reaction solution 1 to a second reaction with the active reaction solution 2 to obtain the graft polymer; Wherein, the coupling agent is dimethyldichlorosilane or dimethyltin dichloride.

4. The preparation method according to claim 3, wherein In step (1), the polar additive is N,N,N',N'-tetramethylethylenediamine; and / or, the molar ratio of the polar additive to the first alkyl lithium is 1.5-3.5:1; And / or, the weight ratio of the polar additive to the polybutadiene-isoprene is 1:25-100.

5. The preparation method according to claim 4, wherein In step (1), the molar ratio of the polar additive to the first alkyl lithium is 2-3:

1.

6. The preparation method according to any one of claims 3 to 5, wherein In step (1), the content of cis-1,4-structure in the polybutadiene-isoprene is ≥95 wt% based on the total amount of isoprene structural units; and / or the number average molecular weight of the polybutadiene-isoprene is 60,000-1,000,000 g / mol, and the molecular weight distribution index of the polybutadiene-isoprene is 3-6; And / or, in the polybutadiene-isoprene, the weight ratio of butadiene structural units to isoprene structural units is 10:90-50:

50.

7. The preparation method according to claim 6, wherein In step (1), the content of cis-1,4-structure in the polybutadiene-isoprene is ≥96.5wt% based on the total amount of isoprene structural units; and / or the number average molecular weight of the polybutadiene-isoprene is 200,000-800,000 g / mol, and the molecular weight distribution index of the polybutadiene-isoprene is 3.5-5; And / or, in the polybutadiene-isoprene, the weight ratio of butadiene structural units to isoprene structural units is 15:85-45:

55.

8. The preparation method according to any one of claims 3 to 5, wherein In step (1), the first reaction is carried out in an inert atmosphere; And / or, the conditions of the first reaction include: the first reaction temperature is room temperature-70° C., the first reaction pressure is 0.1-0.4 MPa, and the first reaction time is 2-12 hr.

9. The preparation method according to claim 8, wherein In step (1), the conditions of the first reaction include: a first reaction temperature of 40-60° C., a first reaction pressure of 0.2-0.3 MPa, and a first reaction time of 4-8 hr.

10. The preparation method according to any one of claims 3 to 5, wherein: In step (2), the additive is tetrahydrofuran or N,N,N',N'-tetramethylethylenediamine; and / or, the molar ratio of the additive to the second alkyl lithium is 0-200:1; and / or, the molar ratio of the total amount of butadiene and styrene to the second alkyl lithium is 100:0.3-3; And / or, the weight ratio of styrene to butadiene is 1:1-5.

11. The preparation method according to claim 10, wherein In step (2), the molar ratio of the additive to the second alkyl lithium is 1.5-150:1; and / or, the molar ratio of the total amount of butadiene and styrene to the second alkyl lithium is 100:0.5-2; And / or, the weight ratio of styrene to butadiene is 1:1.5-4.

12. The preparation method according to any one of claims 3 to 5, wherein The molar ratio of the coupling agent to the second alkyl lithium is 1-1.1:

1.

13. The preparation method according to claim 12, wherein In step (2), the molar ratio of the coupling agent to the second alkyl lithium is 1.02-1.08:

1.

14. The preparation method according to any one of claims 3 to 5, wherein In step (2), the copolymerization reaction is carried out in an inert atmosphere; the copolymerization reaction temperature is 0°C-room temperature, the copolymerization reaction pressure is 0.1-0.4 MPa, and the copolymerization reaction time is 1-3 hr.

15. The preparation method according to claim 14, wherein In step (2), the copolymerization reaction temperature is 5-15° C., the copolymerization reaction pressure is 0.2-0.3 MPa, and the copolymerization reaction time is 1.5-2 hr.

16. The preparation method according to any one of claims 3 to 5, wherein: The first alkyllithium and the second alkyllithium are each independently selected from one or more of methyllithium, ethyllithium, propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, and n-hexyllithium.

17. The preparation method according to claim 16, wherein The first alkyl lithium and the second alkyl lithium are each independently n-butyl lithium.

18. The preparation method according to any one of claims 3 to 5, wherein: In step (3), the weight ratio of the polybutadiene-isoprene contained in the active reaction solution 1 to the styrene-butadiene copolymer contained in the active reaction solution 2 is 55-75:25-45; And / or, the molar ratio of active Li contained in the active reaction solution 1 to active chlorine contained in the active reaction solution 2 is 1.4-1:

1.

19. The preparation method according to claim 18, wherein In step (3), the molar ratio of active Li contained in the active reaction solution 1 to active chlorine contained in the active reaction solution 2 is 1.5-1:

1.

20. The preparation method according to any one of claims 3 to 5, wherein: In step (3), the second reaction is carried out in an inert atmosphere, the second reaction temperature is room temperature-70° C., the second reaction pressure is 0.1-0.4 MPa, and the second reaction time is 2-12 hr.

21. The preparation method according to any one of claims 3 to 5, wherein: In step (3), the second reaction is carried out in an inert atmosphere, the second reaction temperature is 40-60° C., the second reaction pressure is 0.2-0.3 MPa, and the second reaction time is 4-8 hr.

22. The preparation method according to any one of claims 3 to 5, wherein: The polybutadiene-isoprene is prepared by the following method: In the presence of a rare earth catalyst, a butadiene monomer and an isoprene monomer are polymerized in a first organic solvent; the polymerization reaction is terminated with water or ethanol, and the obtained polymerization product solution is precipitated, washed, and dried to obtain polybutadiene-isoprene.

23. The preparation method according to claim 22, wherein The rare earth catalyst comprises a rare earth carboxylate compound, an alkyl aluminum compound, and a chloride; Wherein, the rare earth carboxylate compound is C6-C 10 Neodymium carboxylate; the alkyl aluminum compound is at least one of the compounds represented by the general formula AlR3 and AlHR2, wherein R is a C1-C6 alkyl group; the chloride is AlR'2Cl, wherein R' is a C1-C6 alkyl group; And / or, the molar ratio of the alkyl aluminum compound calculated as aluminum to the rare earth carboxylate calculated as neodymium is 10-80; the molar ratio of the chloride to the rare earth carboxylate calculated as neodymium is 2-4.

24. The preparation method according to claim 22, wherein The polymerization reaction conditions include: a molar ratio of butadiene monomer to isoprene monomer of 1:1-3; a molar amount of the rare earth catalyst calculated as neodymium of 0.015-0.08% of the total molar amount of the butadiene monomer and the isoprene monomer; And / or, the polymerization reaction temperature is room temperature-70° C., the polymerization reaction pressure is 0.1-0.5 MPa, and the polymerization reaction time is 2-8 hr.

25. The preparation method according to claim 24, wherein The polymerization reaction conditions include: a molar ratio of butadiene monomer to isoprene monomer of 1:1.15-2.75; And / or, the polymerization reaction temperature is 40-60° C., the polymerization reaction pressure is 0.3-0.4 MPa, and the polymerization reaction time is 3-6 hr.

26. The preparation method according to claim 22, wherein the first organic solvent, the second organic solvent and the third organic solvent are C5-C 10 Saturated alkanes, C5-C 10 At least one of the cycloalkanes.

27. The preparation method according to claim 22, wherein the first organic solvent, the second organic solvent and the third organic solvent are at least one of hexane, methylcyclopentane, 2-methylpentane, 3-methylpentane, cyclohexane, heptane and octane.

28. A vulcanized rubber obtained from the graft polymer of polybutadiene-styrene grafted with polybutadiene-isoprene according to claim 1 or 2.

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