阅读说明：本技术 超支化丁基橡胶的制备方法 (Preparation method of hyperbranched butyl rubber ) 是由 徐典宏 赵志超 孟令坤 翟云芳 朱晶 李旭 王奇 于 2020-06-24 设计创作，主要内容包括：本发明涉及一种超支化丁基橡胶的制备方法,包括以下步骤：首先将3,9-二氧[5.5]螺环十一烷进行卤化反应,合成出一种长链对称型四卤化物偶联剂1,5-二溴-3,3二(2-溴乙基)戊烷,然后通过新型偶联剂将异戊二烯、苯乙烯和丁二烯三种不同反应单体组成的链段-IR-PS-BR-偶合在一个大分子链上形成一种三元四臂星型结构的共聚物,最后在路易斯酸和质子酸复配的催化体系下,这种三元四臂星型共聚物作为接枝剂与异丁烯和异戊二烯进行阳离子聚合制备出超支化丁基橡胶。该方法解决了丁基橡胶的加工性和物理机械性能的这对矛盾关系问题,实现了丁基橡胶的加工性与物理机械性能的平衡。(The invention relates to a preparation method of hyperbranched butyl rubber, which comprises the following steps: firstly, 3, 9-dioxo [5.5] spiro undecane is subjected to halogenation reaction to synthesize a long-chain symmetrical tetrahalide coupling agent 1, 5-dibromo-3, 3-di (2-bromoethyl) pentane, then a chain segment-IR-PS-BR-consisting of three different reaction monomers of isoprene, styrene and butadiene is coupled on a macromolecular chain through a novel coupling agent to form a ternary four-arm star-shaped copolymer, and finally the ternary four-arm star-shaped copolymer is taken as a grafting agent to be subjected to cationic polymerization with isobutene and isoprene to prepare the hyperbranched butyl rubber under a catalytic system compounded by Lewis acid and protonic acid. The method solves the problem of contradiction between the processability and the physical and mechanical properties of the butyl rubber, and realizes the balance between the processability and the physical and mechanical properties of the butyl rubber.)

1. A preparation method of hyperbranched butyl rubber is characterized by comprising the following steps:

(1) preparation of grafting agent:

a preparation of a coupling agent: according to the total mass percentage of reactants, firstly, 100-200% of deionized water, 3, 9-dioxy [5.5] spiro undecane, a halogenating agent and 1-5% of a catalyst are sequentially added into a reaction kettle under the atmosphere of inert gas, the temperature is raised to 50-80 ℃, after reaction for 1-3 hours, 20-40% of NaOH aqueous solution with the mass concentration of 10-20% is added to terminate the reaction, and finally 200-300% of methane chloride is added to extract, separate, wash and dry to prepare a coupling agent;

b preparation of grafting agent: according to the total mass percentage of the reaction monomers, firstly, under the atmosphere of inert gas, sequentially adding 100-200% of solvent, 10-20% of isoprene, 0.05-0.5% of structure regulator and initiator into a reaction kettle, heating to 45-55 ℃, and reacting until the conversion rate of the isoprene monomer reaches 100%; then sequentially adding 200-300% of solvent, 60-70% of styrene and 0.05-0.5% of structure regulator into the reaction kettle, heating to 60-70 ℃, and reacting for 50-70 min; secondly, sequentially adding 10-30% of butadiene and 0.05-0.3% of structure regulator into the reaction kettle, heating to 70-80 ℃, and reacting until no free monomer exists; finally, heating to 85-90 ℃, adding the coupling agent prepared in the step a for coupling reaction for 60-80 min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet coagulation and drying on glue solution to prepare a grafting agent;

(2) preparation of hyperbranched butyl rubber: according to the total mass percentage of reaction monomers, firstly, 100-200 percent of diluent and solvent are added into a reaction kettle in an inert gas atmosphere, and the volume ratio is 70-30: stirring and dissolving the mixed solvent and the grafting agent which are composed of 30-70% for 20-30 min until the grafting agent is completely dissolved; and then cooling to-75-85 ℃, sequentially adding 100-200% of diluent, 85-95% of isobutene and 1-5% of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-100-90 ℃, then adding 30-50% of diluent and 0.05-2.0% of co-initiator into the polymerization system for stirring and reacting for 1.0-3.0 hr after mixing and aging for 20-30 min at-85-95 ℃, discharging and condensing, washing and drying to obtain the hyperbranched butyl rubber product.

2. The method of claim 1, wherein the grafting agent is a three-way four-armed star copolymer composed of isoprene, styrene, and butadiene: [ -IR-PS-BR- ] nY, the structural general formula is shown in formula I:

wherein Y is 3, 3-diethylpentane; BR is a1, 3-butadiene homopolymer block, and the 1, 2-structure mass content of the BR is 10-20%; PS is a styrene homopolymer block, wherein the mass content of styrene is 60-70%; the IR is an isoprene homopolymer block, the mass content of a1, 2-structure of the isoprene homopolymer block is 10-20%, and n is 2-5.

3. The method according to claim 2, wherein the 1, 3-butadiene content of the ternary four-arm star polymer is 10-30% by mass, the styrene content is 60-70% by mass, and the isoprene content is 10-20% by mass.

4. The method of claim 2, wherein the ternary four-arm star polymer has a number average molecular weight of 5000 to 30000 and a ratio of weight average molecular weight to number average molecular weight of 6.72 to 9.56.

5. The method of claim 1, wherein the halogenating agent is one of liquid chlorine and liquid bromine.

6. The method of claim 5, wherein the halogenating agent is liquid bromine and the molar ratio of the liquid bromine to the 3, 9-dioxo [5.5] spiroundecane is 4.5 to 6.5.

7. The process of claim 1, wherein the catalyst is HCl-CH₃OH, wherein the molar concentration of HCl is 0.1-0.7 mol/L.

8. The method of claim 1, wherein the structure modifier is selected from the group consisting of diethylene glycol dimethyl ether, tetrahydrofuran, diethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether, and triethylamine.

9. The method of claim 8, wherein the structure modifier is tetrahydrofuran.

10. The process of claim 1, wherein the initiator is selected from the group consisting of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, lithium naphthalide, cyclohexyllithium, and dodecyllithium.

11. The method of claim 10, wherein the initiator is n-butyl lithium.

12. The process of claim 1, wherein the coupling agent is 1, 5-dihalo-3, 3-bis (2-haloethyl) pentane.

13. The method of claim 1, wherein the diluent is selected from one of methyl chloride, methylene chloride, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, monofluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane.

14. The method of claim 1, wherein the co-initiator is formulated from an alkyl aluminum halide and a protic acid.

Technical Field

The invention relates to a preparation method of hyperbranched butyl rubber, in particular to a preparation method of hyperbranched butyl rubber by taking a ternary four-arm star-shaped copolymer formed by isoprene, styrene and butadiene as a grafting agent.

Background

It is known that Butyl Rubber (IIR) is produced by the cationic polymerization of isobutylene and a small amount of isoprene. Butyl rubber has been commercialized by Exxon corporation in the 40 th century for over seventy years since now, and has excellent properties such as airtightness, damping properties, thermal aging resistance, ozone resistance, and weather resistance, and thus it is widely used in the fields of manufacturing inner tubes, airtight layers, curing bladders, medical stoppers of tires for vehicles, and the like, and is one of the most important synthetic rubber products.

However, the molecular chain of the butyl rubber is mainly composed of carbon-carbon single bonds, the number of double bonds is small, and the substituent methyl groups are symmetrically arranged, so that the defects of high crystallinity, poor flexibility of the molecular chain, low stress relaxation rate, low vulcanization speed, poor adhesiveness, poor compatibility with other general rubbers and the like exist, and the butyl rubber is easy to excessively flow and deform in the processing process. Therefore, how to balance the physical and mechanical properties and the processability of the butyl rubber becomes a bottleneck for preparing high-performance butyl rubber materials.

In recent years, researchers find that star-shaped branched butyl rubber which is composed of a high-molecular-weight graft structure and a low-molecular-weight linear structure and has a unique three-dimensional net structure has excellent viscoelastic performance, high crude rubber strength and a fast stress relaxation rate, low melt viscosity can be kept in a processing process, a high-molecular-weight polymer can be obtained, and balance and unification of physical and mechanical properties and processing properties are realized. Therefore, the star-branched structure has become one of the hot spots in the research field of future butyl rubber.

In the prior art, the star-branched butyl rubber is mainly prepared by a method of a first-nucleus-second-arm method, a first-arm-second-nucleus method and a nuclear-arm simultaneous method. Such as: US5395885 discloses a star-branched polyisobutylene-polydivinylbenzene polymer, which is synthesized by taking polyisobutylene as an arm, Polydivinylbenzene (PDVB) as a core, a complex of aluminium chloride and water as an initiator, and methyl chloride as a diluent through a first-arm-second-core method at-90 ℃ to-100 ℃. CN 107344982 a discloses a method for producing a wide/bimodal molecular weight distribution butyl rubber, which comprises: mixing isobutene and isoprene at a molar ratio of 97:3 to 99:1, then mixing the mixture with a diluent (methane chloride) to obtain a monomer stream, mixing an initiator (an aluminum chloride system and an HCl/alkylaluminum chloride complex) with the diluent (methane chloride) to obtain an initiator stream, mixing the monomer stream and the initiator stream, conveying the mixture into a first loop reactor zone, and carrying out polymerization reaction for 5-10min at a temperature of-98 ℃ to-96 ℃ and a pressure of 0.3 to 0.4MPa to obtain a first part of butyl rubber slurry; secondly, sending the first part of butyl rubber slurry into a second loop reactor zone, and carrying out polymerization reaction for 5-10min at the temperature of-92 ℃ to-90 ℃ and the pressure of 0.1 to 0.2Mpa to finally obtain the butyl rubber slurry with broad/bimodal molecular weight distribution; and thirdly, contacting the butyl rubber slurry with broad/bimodal molecular weight distribution with water, removing unreacted monomers and a diluent to obtain colloidal particle water, and then dehydrating and drying the colloidal particle water to obtain the butyl rubber with broad/bimodal molecular weight distribution and molecular weight distribution (Mw/Mn) of at least 5.0. CN1427851A discloses a preparation method of butyl rubber with wide molecular weight distribution. The process uses a mixed catalyst system comprising a major amount of an dialkylaluminum dihalide, a minor amount of a monoalkylaluminum dihalide and a minor amount of an aluminoxaneMixtures of (a) to give a broad distribution butyl rubber having a molecular weight distribution of greater than 3.5, up to 7.6. CN101353403B discloses a preparation method of star-branched polyisobutylene or butyl rubber, which adopts a polystyrene/isoprene block copolymer with a silicon-chlorine group at the terminal or a polystyrene/butadiene block copolymer with a silicon-chlorine group at the terminal as a grafting initiating agent for positive ion polymerization, directly participates in the positive ion polymerization in a positive ion polymerization system of a mixed solvent with a ratio of methane chloride to cyclohexane v: v of 20-80/80-20 at the temperature of 0-100 ℃, and prepares a star-branched polyisobutylene or butyl rubber product by the participation of an unsaturated chain in a grafting reaction through the initiated positive ion polymerization of the silicon-chlorine group. CN01817708.5 provides a method of making star-branched polymers by adding a multiolefin cross-linking agent, such as divinylbenzene, and a chain transfer agent, such as 2,4, 1-trimethyl-1-pentene, to a mixture of isoolefin monomers and diolefin monomers. CN88108392.5 discloses a star-shaped grafted butyl rubber with a comb-shaped structure, which is prepared by using a hydrochloric acid polystyrene-isoprene copolymer as a multifunctional initiator or using polystyrene-butadiene or polystyrene-isoprene as a grafting agent. CN 107793535A provides a butyl rubber having a molecular weight of 90 to 260 ten thousand, Log (MW)>And contains structural units derived from isobutylene, structural units derived from a conjugated diene, and optionally structural units derived from an aryl olefin. US3780002 teaches a composite initiator using a halide of a metal from group II or III of the periodic Table of the elements in combination with a tetrahalide of a metal from group IV of the periodic Table of the elements, e.g. AlCl₃And TiC1₄Combined use, or A1C1₃And SnC1₄The composite use enables each initiator to independently initiate cationic polymerization, and butyl rubber with molecular weight distribution index Mw/Mn of above 5.0 is synthesized under the conventional butadiene rubber polymerization condition.

CN 101353386A discloses an initiation system for cationic polymerization of star-branched polyisobutylene or butyl rubber, which is composed of an initiation-grafting agent, a coinitiator and a nucleophilic reagent, and is used for initiating vinyl monomers to perform homopolymerization, block copolymerization, star polymerization and graft copolymerization, wherein the obtained polymer presents obvious bimodal distribution. Puskas (Catalysts for manufacturing of IIR with bi-modal molecular weight distribution: US, 5194538[ P ] 1993-3-16.) adopts trimesic acid as raw material to synthesize initiator tri-cumyl alcohol with a three-arm structure, and then adopts a tri-cumyl alcohol/aluminum trichloride initiating system to initiate isobutylene and isoprene to copolymerize in an inert organic solvent under the condition of-120 to-50 ℃ to synthesize star-shaped branched butyl rubber with bi-modal molecular weight distribution. Wieland et al (Synthesis of new graft copolymer polymerization by polymerization of the 1,1-diphenylethylene technology and cationic polymerization [ J ]. Polymer Science: Polymer Chemistry, 2002, 40: 3725-co-3733.) synthesized a macroinitiator P (MMA-b-St-co-CMS) containing the three members of 4-chloromethylstyrene, styrene and methyl methacrylate in the presence of 1, 2-Diphenylethylene (DPE) by a radical polymerization method, and then initiated cationic polymerization of isobutylene and isoprene to successfully prepare the multi-arm star butyl rubber. Wubo et al (Davang S H, et al. Ski resistant coatings for air craft carrier decks [ J ]. Coat Technol, 1980, 52 (671): 65-69.) prepared a poly (isoprene-styrene) block copolymer as a grafting agent by living anionic polymerization, and prepared star-branched butyl rubber exhibiting significant bimodal properties by living cationic polymerization in an initiation system of 2-chloro-2, 4, 4-trimethylpentane/titanium tetrachloride/proton scavenger.

Disclosure of Invention

The invention aims to provide a preparation method of hyperbranched butyl rubber. Firstly, carrying out halogenation reaction on 3, 9-dioxo [5.5] spiro undecane to synthesize a novel tetrahalide coupling agent, then coupling the novel tetrahalide coupling agent with isoprene, styrene and butadiene reaction monomers to prepare a ternary four-arm star-shaped copolymer, and finally carrying out cationic polymerization on the ternary four-arm star-shaped copolymer as a grafting agent, isobutene and isoprene to prepare the hyperbranched butyl rubber under a catalytic system compounded by Lewis acid and protonic acid. The method solves the problems of extrusion swelling and low stress relaxation rate of the butyl rubber during processing, and realizes good processability of the hyperbranched butyl rubber on the premise of sufficient crude rubber strength and good air tightness.

All the percentages in the present invention are percentages by mass.

The preparation of the hyperbranched butyl rubber is carried out in a reaction kettle, and the specific preparation process comprises the following steps:

(1) preparation of grafting agent:

a preparation of a coupling agent: according to the total mass percentage of reactants, firstly, 100-200% of deionized water, 3, 9-dioxo [5.5] spiro undecane, a halogenating agent and 1-5% of a catalyst are sequentially added into a reaction kettle under the atmosphere of inert gas, the temperature is raised to 50-80 ℃, after the reaction is carried out for 1-3 hours, 20-40% of NaOH aqueous solution with the mass concentration of 10-20% is added to stop the reaction, and finally, 200-300% of monochloromethane is added to carry out extraction, separation, washing and drying to prepare the coupling agent 1, 5-dihalo-3, 3-bis (2-haloethyl) pentane (the yield is 85-95%).

b preparation of grafting agent: firstly, in an inert gas atmosphere, sequentially adding 100-200% of a solvent, 10-20% of isoprene, 0.05-0.5% of a structure regulator and an initiator into a reaction kettle, heating to 45-55 ℃, and reacting until the conversion rate of the isoprene monomer reaches 100%; then sequentially adding 200-300% of solvent, 60-70% of styrene and 0.05-0.5% of structure regulator into the reaction kettle, heating to 60-70 ℃, and reacting for 50-70 min to form an-IR-PS-chain segment, wherein the conversion rate of a styrene monomer reaches 100%; secondly, sequentially adding 10-30% of butadiene and 0.05-0.3% of structure regulator into the reaction kettle, heating to 70-80 ℃, and reacting until no free monomer exists to form an-IR-PS-BR-chain segment; and (b) finally, heating to 85-90 ℃, adding the coupling agent prepared in the step (a) for coupling reaction for 60-80 min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet coagulation and drying on the glue solution to prepare the grafting agent of the ternary four-arm star-shaped copolymer [ -IR-PS-BR- ] nY.

(2) Preparation of hyperbranched butyl rubber: firstly, adding 100-200% of a diluent/solvent V: the V ratio is 70-30: 30-70 percent of mixed solvent and 2-8 percent of grafting agent, stirring and dissolving for 20-30 min until the grafting agent is completely dissolved; and then cooling to-75 to-85 ℃, sequentially adding 100 to 200 percent of diluent, 85 to 95 percent of isobutene and 1 to 5 percent of isoprene, stirring and mixing until the temperature of the polymerization system is reduced to-100 to-90 ℃, then adding 30 to 50 percent of diluent and 0.05 to 2.0 percent of co-initiator into the polymerization system for stirring and reacting for 1.0 to 3.0 hours after mixing and aging for 20 to 30 minutes at-85 to-95 ℃, discharging and condensing, washing and drying to obtain the hyperbranched butyl rubber product.

The grafting agent is a ternary four-arm star-shaped copolymer [ -IR-PS-BR- ] nY composed of isoprene, styrene and butadiene, and the structural general formula of the grafting agent is shown as a formula I:

wherein Y is 3, 3-diethylpentane; BR is a1, 3-butadiene homopolymer block, and the 1, 2-structure content of the BR is 10-20%; PS is a styrene homopolymer block, wherein the styrene content is 60-70%; IR is an isoprene homopolymer block, the content of a1, 2-structure of the isoprene homopolymer block is 10-20%, and n is 2-5; the content of 1, 3-butadiene, styrene and isoprene in the ternary four-arm star polymer is 10-30%, 60-70% and 10-20%; the number average molecular weight (Mn) of the ternary four-arm star polymer is 5000-30000, and the molecular weight distribution (Mw/Mn) is 6.72-9.56.

The halogenating agent is one of liquid chlorine and liquid bromine, preferably liquid bromine, the dosage of the halogenating agent is determined according to the dosage of the 3, 9-dioxo [5.5] spiroundecane, and the molar ratio of the dosage of the liquid bromine to the 3, 9-dioxo [5.5] spiroundecane is 4.5-6.5.

The catalyst of the invention is HCl-CH₃A mixed aqueous solution of OH, wherein the molar concentration of HCl is: 0.1 to 0.7 mol/L.

The structure regulator of the invention is a polar organic compound which generates solvation effect in a polymerization system and can regulate the reactivity ratio of styrene and butadiene so as to ensure that the styrene and the butadiene are randomly copolymerized. Such polar organic compound is selected from one of diethylene glycol dimethyl ether (2G), Tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME), triethylamine, preferably Tetrahydrofuran (THF).

The initiator is an alkyl monolithium compound, namely RLi, wherein R is a saturated aliphatic alkyl, alicyclic alkyl, aromatic alkyl containing 1-20 carbon atoms or a composite group of the above groups. The alkyl monolithium compound is selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthyllithium, cyclohexyllithium and dodecyllithium, preferably n-butyllithium. The amount of organolithium added is determined by the molecular weight of the polymer being designed.

The coupling agent used in the invention is 1, 5-dihalo-3, 3-di (2-haloethyl) pentane, the dosage of the coupling agent is determined according to the amount of an initiator, a star polymer with a four-arm structure is coupled by an excessive coupling agent, and the molar ratio of the dosage of the coupling agent to the total organic lithium is 3.0-5.0.

The diluent is halogenated alkane, wherein halogen atoms in the halogenated alkane can be chlorine, bromine or fluorine; the number of carbon atoms in the halogenated alkane is C1-C4. The alkyl halide is selected from one of methyl chloride, methylene chloride, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, monofluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride and fluorobutane, preferably methyl chloride.

The coinitiator is prepared by compounding alkyl aluminum halide and protonic acid according to different proportions. The alkyl aluminum halide is at least one selected from the group consisting of diethylaluminum monochloride, diisobutylaluminum monochloride, methylaluminum dichloroide, ethylaluminum sesquichloride, isobutylaluminum sesquichloride, n-propylaluminum dichloride, isopropylaluminum dichloroide, dimethylaluminum chloride and ethylaluminum chloride, preferably ethylaluminum sesquichloride. The protonic acid is selected from HCI, HF, HBr, H₂SO₄、H₂CO₃、H₃PO₄And HNO₃Preferably HCI. Wherein the co-introductionThe total addition amount of the hair agent is 0.1-3.0%, and the molar ratio of the protonic acid to the alkyl aluminum halide is 0.01: 1-0.1: 1.

The polymerization reaction of the present invention is carried out in an oxygen-free, water-free, preferably inert gas atmosphere. The polymerization and dissolution are carried out in a hydrocarbon solvent, which is a hydrocarbon solvent including straight-chain alkanes, aromatic hydrocarbons and cycloalkanes, and is selected from one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene, preferably cyclohexane.

The inert gas is nitrogen or one of all element gases in group 0 of the periodic table of elements, which do not contain radon.

The invention firstly carries out halogenation reaction on 3, 9-dioxo [5.5] spiro undecane to synthesize a novel coupling agent 1, 5-dibromo-3, 3 di (2-bromoethyl) pentane, then couples the pentane with isoprene, styrene and butadiene reaction monomers to prepare a ternary four-arm star polymer [ -IR-PS-BR- ] nY (shown in figure 1), and finally prepares hyperbranched butyl rubber with ultra-wide molecular weight distribution by taking the ternary four-arm star polymer as a grafting agent, isobutene and isoprene through cationic polymerization under a catalyst system compounded by alkyl aluminum halide and protonic acid (shown in figure 2).

The invention utilizes the coupling of a novel coupling agent to combine chain segments consisting of three different reaction monomers-IR-PS-BR-on a macromolecular chain to form a ternary four-arm star structure, thus, different structural unit performances in the chain segment can be organically combined together and play a role in a synergistic manner, the regularity of the molecular chain in the copolymerization of isobutene and isoprene can be obviously destroyed by utilizing a four-arm star structure, the disorder of the chain segment is increased, the molecular weight distribution is obviously widened, meanwhile, the-IR-and-BR-structural units contain a certain amount of unsaturated double bonds, which can effectively improve the flexibility of chain segments, the synergistic effect of the two aspects ensures that the butyl rubber can obtain good viscoelastic property, has fast stress relaxation rate, and obviously improves the processability of the butyl rubber. In addition, the PS structural unit contains a large number of benzene rings, so that the reduction of strength and air tightness caused by broadening of molecular weight distribution is avoided, and the high strength and good air tightness of the butyl rubber are ensured.

The invention solves the problem of contradiction relation between the processability and the physical and mechanical properties of the butyl rubber by the design of the ternary four-arm star structure, and finally realizes the balance between the processability and the physical and mechanical properties of the butyl rubber. The preparation method provided by the invention has the characteristics of short process flow, controllable molecular weight of the product, designable molecular structure, suitability for industrial production and the like.

Drawings

FIG. 1 shows [ -IR-PS-BR-]_nAnd Y is a synthetic route map.

FIG. 2 is 1^#Sample of-butyl rubber IIR301 with 2^#Comparison of the GPC spectra of the samples of example 1.

Detailed Description

The following examples illustrate the invention in detail: the present example is carried out on the premise of the technical scheme of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and the experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.

The following examples and comparative examples are given to illustrate the effects of the present invention, but the scope of the present invention is not limited to these examples and comparative examples. All the raw materials used in the examples are of industrial polymerization grade, and are used after purification without other special requirements.

(1) The raw material sources are as follows:

styrene, butadiene, Polymer grade, Petroleum Lanzhou petrochemical Co Ltd

Isobutene, isoprene, Polymer grade Zhejiang Credit New materials Co Ltd

N-butyl lithium, 98% purity Nanjing Tongtiang chemical Co., Ltd

3, 9-dioxo [5.5] spiroundecane having a purity of 99% of sesquiethylaluminum chloride from Hubei Ferry chemical Co., Ltd and a purity of 98% of carbofuran science Co., Ltd

Other reagents are all commercial products

(2) The analysis and test method comprises the following steps:

determination of the molecular weights and their distribution: the measurement was carried out by using 2414 Gel Permeation Chromatograph (GPC) manufactured by Waters corporation, USA. Taking polystyrene standard sample as calibration curve, tetrahydrofuran as mobile phase, column temperature of 40 deg.C, sample concentration of 1mg/ml, sample amount of 50 μ L, elution time of 40min, and flow rate of 1 ml/min^-1。

Determination of Mooney viscosity and stress relaxation: the measurement was carried out by using a Mooney viscometer model GT-7080-S2 manufactured by Taiwan high-speed railway. The Mooney relaxation time, determined with a large rotor at 125 ℃ C (1+8) according to the method of GB/T1232.1-2000, is 120 s.

Measurement of airtightness: the permeability was determined using an automated air tightness tester according to ISO 2782:1995 with a test gas of N₂The test temperature is 23 ℃, and the test sample is a circular sea piece with the diameter of 8cm and the thickness of 1 mm.

Tensile strength: the method in standard GB/T528-2009 is executed.

Characterization of the degree of branching: degree of branching-polymer molecular weight after branching/polymer molecular weight before branching.

Example 1

(1) Preparation of grafting agent:

a preparation of a coupling agent: firstly, in a 4L stainless steel polymerization kettle with a jacket, introducing argon gas for 3 times of replacement, and sequentially adding 700g of deionized water and 60g of 3, 9-dioxygen [5.5]]Spiroundecane, 310g of liquid bromine, 14g of HCl-CH₃OH solution (HCl molar concentration: 0.5mol/L), heating to 55 ℃, reacting for 1.5hr, adding 250g of NaOH aqueous solution with the mass concentration of 15% to terminate the reaction, and finally adding 800g of monochloromethane to extract, separate, wash and dry to obtain the coupling agent 1, 5-dibromo-3, 3 bis (2-bromoethyl) pentane (yield 92%).

b preparation of grafting agent: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 2 times, sequentially adding 1650g of cyclohexane, 155g of isoprene, 1.5g of THF and 23.1mmo1 n-butyllithium into the polymerization kettle, heating to 45 ℃, and reacting for 40min to form an IR chain segment; then 3100g cyclohexane, 910g styrene, 2.1g THF were added to the polymerization vessel in sequence, the temperature was raised to 60 ℃ and the reaction was carried out for 50min to form-IR-PS-chainA segment; secondly, sequentially adding 175g of 1, 3-butadiene and 1.9g of THF into the polymerization kettle, heating to 70 ℃, and reacting for 30min to form an-IR-PS-BR-chain segment; finally heating to 85 ℃, adding 75.5mmo 11, 5-dibromo-3, 3-di (2-bromoethyl) pentane, reacting for 60min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet condensation and drying on the glue solution to obtain the binary four-arm star polymer [ -IR-PS-BR-]_nY (Mn 9150, Mw/Mn 6.81).

(2) Preparation of hyperbranched butyl rubber: firstly, in a 4L stainless steel reaction kettle with a jacket, nitrogen is introduced for 3 times for replacement, 620g of monochloromethane, 310g of cyclohexane, [ -IR-PS-BR-]_n13.5g of Y grafting agent is stirred and dissolved for 20min until the grafting agent is completely dissolved; then cooling to-75 ℃, sequentially adding 720g of methane chloride, 425g of isobutene and 14g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-90 ℃, then mixing 160g of methane chloride, 0.91g of sesquiethylaluminum chloride and 0.025g of HCl at-85 ℃, aging for 20min, then adding the materials into the polymerization system together, stirring and reacting for 1.0hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Example 2

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 1.

b preparation of grafting agent: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 1820g of cyclohexane, 186g of isoprene, 2.3g of THF and 25.1mmo1 n-butyllithium into the polymerization kettle, heating to 48 ℃, and reacting for 45min to form an IR chain segment; then 3200g of cyclohexane, 930g of styrene and 2.6g of THF are sequentially added into the polymerization kettle, the temperature is raised to 62 ℃, and the reaction is carried out for 55min to form an-IR-PS-chain segment; secondly, sequentially adding 203g of 1, 3-butadiene and 2.1g of THF into the polymerization kettle, heating to 72 ℃, and reacting for 35min to form an-IR-PS-BR-chain segment; finally heating to 85 ℃, adding 80.6mmo 11, 5-dibromo-3, 3-di (2-bromoethyl) pentane, reacting for 65min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet coagulation and drying on the glue solution to obtain the binary four-arm star polymerThe compound [ -IR-PS-BR-]_nY (Mn of 11120, Mw/Mn of 7.21).

(2) Preparation of hyperbranched butyl rubber: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, 600g of methane chloride, 380g of cyclohexane and [ -IR-PS-BR-]_n20.2g of Y grafting agent is stirred and dissolved for 25min until the grafting agent is completely dissolved; then cooling to-77 ℃, sequentially adding 720g of methane chloride, 435g of isobutene and 17g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-90 ℃, then mixing 180g of methane chloride, 1.21g of sesquiethylaluminum chloride and 0.085g of HCl at-87 ℃, aging for 20min, then adding the materials into the polymerization system together, stirring and reacting for 1.5hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Example 3

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 1.

b preparation of grafting agent: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2020g of cyclohexane, 200g of isoprene, 3.5g of THF and 28.1mmo1 n-butyllithium into the polymerization kettle, heating to 50 ℃, and reacting for 50min to form an IR chain segment; then 3300g cyclohexane, 970g styrene and 4.1g THF are added into the polymerization kettle in sequence, the temperature is raised to 65 ℃, and the reaction is carried out for 60min, so as to form-IR-PS-chain segment; secondly, 254g of 1, 3-butadiene and 2.8g of THF are sequentially added into a polymerization kettle, the temperature is raised to 75 ℃, and the reaction is carried out for 40min to form an-IR-PS-BR-chain segment; finally heating to 87 ℃, adding 100.6 mmols 11, 5-dibromo-3, 3-di (2-bromoethyl) pentane, reacting for 70min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet condensation and drying on the glue solution to obtain the binary four-arm star polymer [ -IR-PS-BR-]_nY (Mn 15350, Mw/Mn 7.92).

(2) Preparation of hyperbranched butyl rubber: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, and 570g of monochloromethane, 410g of cyclohexane and [ -IR-PS-BR-]_n30.5g of Y grafting agent is stirred and dissolved for 25min until the grafting agent is dissolvedCompletely dissolving; then cooling to-80 ℃, sequentially adding 850g of methane chloride, 455g of isobutene and 20g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-92 ℃, then mixing 200g of methane chloride, 2.85g of sesquiethylaluminum chloride and 0.135g of HCl at-90 ℃, aging for 25min, then adding the mixture into the polymerization system together, stirring and reacting for 2.0hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Example 4

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 1.

b preparation of grafting agent: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2310g of cyclohexane, 230g of isoprene, 4.1g of THF and 30.5mmo1 n-butyllithium into the polymerization kettle, heating to 52 ℃, and reacting for 53min to form an IR chain segment; then, 3500g of cyclohexane, 1010g of styrene and 4.7g of THF are sequentially added into the polymerization kettle, the temperature is raised to 67 ℃, and the reaction is carried out for 63min, so as to form an-IR-PS-chain segment; secondly, 285g of 1, 3-butadiene and 3.2g of THF are sequentially added into the polymerization kettle, the temperature is raised to 75 ℃, and the reaction is carried out for 45min to form an-IR-PS-BR-chain segment; finally heating to 87 ℃, adding 120.5mmo 11, 5-dibromo-3, 3-di (2-bromoethyl) pentane, reacting for 75min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet condensation and drying on the glue solution to obtain the binary four-arm star polymer [ -IR-PS-BR-]_nY (Mn 22580, Mw/Mn 8.32).

(2) Preparation of hyperbranched butyl rubber: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, 470g of monochloromethane, 520g of cyclohexane and [ -IR-PS-BR-]_n35.5g of Y grafting agent is stirred and dissolved for 27min until the grafting agent is completely dissolved; cooling to-82 deg.C, sequentially adding 910g of monochloromethane, 465g of isobutene and 30g of isoprene, stirring and mixing until the temperature of the polymerization system is reduced to-92 deg.C, mixing 220g of monochloromethane, 3.12g of sesquiethylaluminum chloride and 0.215g of HCl at-90 deg.C, aging for 25min, adding into the polymerization system, stirring and reacting for 2.5hr, dischargingAnd (4) coagulating, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Example 5

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 1.

b preparation of grafting agent: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2510g of cyclohexane, 250g of isoprene, 4.5g of THF and 33.5mmo1 n-butyllithium into the polymerization kettle, heating to 52 ℃, and reacting for 55min to form an IR chain segment; then, 3500g of cyclohexane, 1050g of styrene and 4.9g of THF are sequentially added into the polymerization kettle, the temperature is raised to 67 ℃, and the reaction is carried out for 65min, so as to form an-IR-PS-chain segment; secondly, sequentially adding 300g of 1, 3-butadiene and 3.6g of THF into the polymerization kettle, heating to 75 ℃, and reacting for 45min to form an-IR-PS-BR-chain segment; finally, the temperature is raised to 87 ℃, 130.2mmo11, 5-dibromo-3, 3-di (2-bromoethyl) pentane is added for reaction for 77min, the coupled reaction mixture is treated by water after the reaction is finished, and the glue solution is coagulated and dried by a wet method to prepare the binary four-arm star polymer [ -IR-PS-BR-]_nY (Mn 25780, Mw/Mn 8.73).

(2) Preparation of hyperbranched butyl rubber: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, and 430g of monochloromethane, 560g of cyclohexane and [ -IR-PS-BR-]_n37.5g of Y grafting agent is stirred and dissolved for 27min until the grafting agent is completely dissolved; then cooling to-84 ℃, sequentially adding 1010g of methane chloride, 475g of isobutene and 35g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-93 ℃, then mixing 240g of methane chloride, 4.12g of aluminum sesquiethylate chloride and 0.325g of HCl at-92 ℃, aging for 27min, then adding the mixture into the polymerization system together, stirring and reacting for 2.7hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Example 6

(1) Preparation of grafting agent:

a preparation of a coupling agent: firstly, introducing argon into a 4L stainless steel polymerization kettle with a jacketThe gas exchange is carried out for 4 times, 600g of deionized water and 65g of 3, 9-dioxy [5.5] are sequentially added into a polymerization kettle]Spiroundecane, 300g of liquid chlorine, 30g of HCl-CH₃OH solution (HCl molar concentration: 0.7mol/L), heating to 80 deg.C, reacting for 3.0hr, adding 300g NaOH aqueous solution with mass concentration of 20% to terminate the reaction, and finally adding 900g methane chloride to extract, separate, wash and dry to obtain the coupling agent 1, 5-dichloro-3, 3 bis (2-chloroethyl) pentane (yield 95%).

b preparation of grafting agent: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2650g of cyclohexane, 270g of isoprene, 4.9g of THF and 35.5mmo1 n-butyllithium into the polymerization kettle, heating to 55 ℃, and reacting for 60min to form an IR chain segment; then, 3500g of cyclohexane, 1070g of styrene and 5.2g of THF are sequentially added into a polymerization kettle, the temperature is raised to 70 ℃, and the reaction is carried out for 70min, so as to form an-IR-PS-chain segment; secondly, sequentially adding 350g of 1, 3-butadiene and 3.9g of THF into the polymerization kettle, heating to 80 ℃, and reacting for 50min to form an-IR-PS-BR-chain segment; finally heating to 90 ℃, adding 150.2mmo 11, 5-dichloro-3, 3 di (2-chloroethyl) pentane, reacting for 80min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet condensation and drying on the glue solution to obtain the binary four-arm star polymer [ -IR-PS-BR-]_nY (Mn 29080, Mw/Mn 9.23).

(2) Preparation of hyperbranched butyl rubber: firstly, in a 4L stainless steel reaction kettle with a jacket, nitrogen is introduced for replacement for 3 times, 400g of methane chloride, 580g of cyclohexane and [ -IR-PS-BR-]_n40.0g of Y grafting agent is stirred and dissolved for 30min until the grafting agent is completely dissolved; and then cooling to-85 ℃, sequentially adding 1000g of methane chloride, 485g of isobutene and 45g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-95 ℃, then mixing 250g of methane chloride, 5.02g of aluminum sesquiethylate chloride and 0.425g of HCl at-95 ℃, aging for 30min, then adding the mixture into the polymerization system together, stirring and reacting for 3.0hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Comparative example 1

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 1.

b preparation of grafting agent: the same as in example 1.

(2) Preparation of hyperbranched butyl rubber: the other conditions were the same as in example 1 except that [ -IR-PS-BR-]_nThe amount of Y grafting agent added was 5.2g, i.e.: firstly, in a 4L stainless steel reaction kettle with a jacket, nitrogen is introduced for 3 times for replacement, 620g of monochloromethane, 310g of cyclohexane, [ -IR-PS-BR-]_n5.2g of Y grafting agent is stirred and dissolved for 20min until the grafting agent is completely dissolved; then cooling to-75 ℃, sequentially adding 720g of methane chloride, 425g of isobutene and 14g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-90 ℃, then mixing 160g of methane chloride, 0.91g of sesquiethylaluminum chloride and 0.025g of HCl at-85 ℃, aging for 20min, then adding the materials into the polymerization system together, stirring and reacting for 1.0hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Comparative example 2

(1) Preparation of grafting agent:

preparation of grafting agent: the other conditions were the same as in example 2 except that: in the synthesis process, a coupling agent 1, 5-dibromo-3, 3 di (2-bromoethyl) pentane is not added, namely: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 1820g of cyclohexane, 186g of isoprene, 2.3g of THF and 25.1mmo1 n-butyllithium into the polymerization kettle, heating to 48 ℃, and reacting for 45min to form an IR chain segment; then 3200g of cyclohexane, 930g of styrene and 2.6g of THF are sequentially added into the polymerization kettle, the temperature is raised to 62 ℃, and the reaction is carried out for 55min to form an-IR-PS-chain segment; secondly, sequentially adding 203g of 1, 3-butadiene and 2.1g of THF into the polymerization kettle, heating to 72 ℃, and reacting for 35min to form an-IR-PS-BR-chain segment; finally heating to 85 ℃, reacting for 65min, treating the coupled reaction mixture with water after the reaction is finished, and carrying out wet condensation and drying on the glue solution to obtain the ternary single-arm linear polymer [ -IR-PS-BR-]_n(Mn of 9230 and Mw/Mn of 2.86).

(2) Preparation of hyperbranched butyl rubberPreparing: the other conditions were the same as in example 2 except that: no [ -IR-PS-BR-]_nY grafting agent, but adding [ -IR-PS-BR-]_nGrafting agents, namely: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, 600g of methane chloride, 380g of cyclohexane and [ -IR-PS-BR-]_n20.2g of grafting agent is stirred and dissolved for 25min until the grafting agent is completely dissolved; then cooling to-77 ℃, sequentially adding 720g of methane chloride, 435g of isobutene and 17g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-90 ℃, then mixing 180g of methane chloride, 1.21g of sesquiethylaluminum chloride and 0.085g of HCl at-87 ℃, aging for 20min, then adding the materials into the polymerization system together, stirring and reacting for 1.5hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Comparative example 3

(1) Preparation of grafting agent: the other conditions were the same as in example 3 except that: in the synthesis process, a coupling agent 1, 5-dibromo-3, 3 bis (2-bromoethyl) pentane is not added, but a conventional coupling agent tin tetrachloride is added, namely: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2020g of cyclohexane, 200g of isoprene, 3.5g of THF and 28.1mmo1 n-butyllithium into the polymerization kettle, heating to 50 ℃, and reacting for 50min to form an IR chain segment; then 3300g cyclohexane, 970g styrene and 4.1g THF are added into the polymerization kettle in sequence, the temperature is raised to 65 ℃, and the reaction is carried out for 60min, so as to form-IR-PS-chain segment; secondly, 254g of 1, 3-butadiene and 2.8g of THF are sequentially added into a polymerization kettle, the temperature is raised to 75 ℃, and the reaction is carried out for 40min to form an-IR-PS-BR-chain segment; finally, the temperature is raised to 87 ℃, 100.6mmo1 stannic chloride is added for reaction for 70min, the reaction mixture after coupling is treated by water after the reaction is finished, and the glue solution is coagulated and dried by a wet method to prepare the binary four-arm star polymer [ -IR-PS-BR-]_nY₁(Mn 12140, Mw/Mn 4.32).

(2) Preparation of hyperbranched butyl rubber: the other conditions were the same as in example 3 except that: no [ -IR-PS-BR-]_nY grafting agent, but adding [ -IR-PS-BR-]_nY₁Grafting agents, namely: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, and 570g of monochloromethane, 410g of cyclohexane and [ -IR-PS-BR-]_nY₁30.5g of grafting agent, stirring and dissolving for 25min until the grafting agent is completely dissolved; then cooling to-80 ℃, sequentially adding 850g of methane chloride, 455g of isobutene and 20g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-92 ℃, then mixing 200g of methane chloride, 2.85g of sesquiethylaluminum chloride and 0.135g of HCl at-90 ℃, aging for 25min, then adding the mixture into the polymerization system together, stirring and reacting for 2.0hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Comparative example 4

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 4.

b preparation of grafting agent: the other conditions were the same as in example 4 except that: no monomer styrene is added in the synthesis process, namely: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2310g of cyclohexane, 230g of isoprene, 4.1g of THF and 30.5mmo1 n-butyllithium into the polymerization kettle, heating to 52 ℃, and reacting for 53min to form an IR chain segment; then, 3500g of cyclohexane and 4.7g of THF are sequentially added into the polymerization kettle, the temperature is raised to 67 ℃, and the reaction is carried out for 63min, so as to form an-IR-chain segment; secondly, 285g of 1, 3-butadiene and 3.2g of THF are sequentially added into the polymerization kettle, the temperature is raised to 75 ℃, and the reaction is carried out for 45min to form an-IR-PS-BR-chain segment; finally heating to 87 ℃, adding 120.5mmo 11, 5-dibromo-3, 3-di (2-bromoethyl) pentane, reacting for 75min, treating the coupled reaction mixture with water after the reaction is finished, and performing wet condensation and drying on the glue solution to obtain the binary four-arm star polymer [ -IR-BR-]_nY (Mn of 8130, Mw/Mn of 5.32).

(2) Preparation of hyperbranched butyl rubber: the other conditions were the same as in example 4 except that: no [ -IR-PS-BR-]_nY grafting agent, but adding [ -IR-BR-]_nY grafting agent, namely: firstly, 4L with jacketIntroducing nitrogen into a stainless steel reaction kettle for 3 times of replacement, adding 470g of monochloromethane, 520g of cyclohexane, [ -IR-BR-]_n35.5g of Y grafting agent is stirred and dissolved for 27min until the grafting agent is completely dissolved; and then cooling to-82 ℃, sequentially adding 910g of methane chloride, 465g of isobutene and 30g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-92 ℃, then mixing 220g of methane chloride, 3.12g of aluminum sesquiethylate chloride and 0.215g of HCl at-90 ℃, aging for 25min, then adding the mixture into the polymerization system together, stirring and reacting for 2.5hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Comparative example 5

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 5.

b preparation of grafting agent: the other conditions were the same as in example 5 except that: in the process of synthesis

No IR segment is formed without addition of isoprene monomer, i.e.: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2510g of cyclohexane, 4.5g of THF and 33.5mmo1 n-butyllithium into the polymerization kettle, heating to 52 ℃, then sequentially adding 3500g of cyclohexane, 1050g of styrene and 4.9g of THF into the polymerization kettle, heating to 67 ℃, and reacting for 65min to form a-PS-chain segment; secondly, sequentially adding 300g of 1, 3-butadiene and 3.6g of THF into the polymerization kettle, heating to 75 ℃, and reacting for 45min to form a-PS-BR-chain segment; finally, the temperature is raised to 87 ℃, 130.2mmo11, 5-dibromo-3, 3-di (2-bromoethyl) pentane is added for reaction for 77min, the reaction mixture after the coupling is treated by water after the reaction is finished, and the glue solution is coagulated and dried by a wet method to prepare the binary four-arm star polymer [ -PS-BR-]_nY (Mn 17650, Mw/Mn 5.73).

(2) Preparation of hyperbranched butyl rubber: the other conditions were the same as in example 5 except that: no [ -IR-PS-BR-]_nY grafting agent, but adding [ -PS-BR-]_nY grafting agent, namely: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, and monochloro is added into a polymerization kettle430g of methane, 560g of cyclohexane [ -PS-BR-]_n37.5g of Y grafting agent is stirred and dissolved for 27min until the grafting agent is completely dissolved; then cooling to-84 ℃, sequentially adding 1010g of methane chloride, 475g of isobutene and 35g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-93 ℃, then mixing 240g of methane chloride, 4.12g of aluminum sesquiethylate chloride and 0.325g of HCl at-92 ℃, aging for 27min, then adding the mixture into the polymerization system together, stirring and reacting for 2.7hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

Comparative example 6

(1) Preparation of grafting agent:

a preparation of a coupling agent: the same as in example 6.

b preparation of grafting agent: the other conditions were the same as in example 6 except that: 1, 3-butadiene monomer is not added in the synthesis process, and a BR chain segment is not formed, namely: firstly, introducing argon into a 15L stainless steel reaction kettle with a jacket for replacement for 3 times, sequentially adding 2650g of cyclohexane, 270g of isoprene, 4.9g of THF and 35.5mmo1 n-butyllithium into the polymerization kettle, heating to 55 ℃, and reacting for 60min to form an IR chain segment; then, 3500g of cyclohexane, 1070g of styrene and 5.2g of THF are sequentially added into a polymerization kettle, the temperature is raised to 70 ℃, and the reaction is carried out for 70min, so as to form an-IR-PS-chain segment; finally heating to 90 deg.C, adding 150.2mmo 11, 5-dichloro-3, 3 di (2-chloroethyl) pentane, reacting for 80min, treating the coupled reaction mixture with water after reaction, wet coagulating the glue solution, and drying to obtain binary four-arm star polymer [ -PS-IR]_nY (Mn 22130, Mw/Mn 4.16).

(2) Preparation of hyperbranched butyl rubber: the other conditions were the same as in example 6 except that: no [ -IR-PS-BR-]_nY grafting agent, but adding [ -PS-IR]_nY grafting agent, namely: firstly, nitrogen is introduced into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, 400g of methane chloride, 580g of cyclohexane and [ -PS-IR ] are added into a polymerization kettle]_n40.0g of Y grafting agent is stirred and dissolved for 30min until the grafting agent is completely dissolved; then cooling to-85 deg.C, and sequentially adding monochloromethane 1000g of isobutene, 485g of isobutene and 45g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-95 ℃, then mixing 250g of methane chloride, 5.02g of aluminum sesquiethylate chloride and 0.425g of HCl at-95 ℃, aging for 30min, then adding the mixture into the polymerization system together, stirring and reacting for 3.0hr, discharging, condensing, washing and drying to obtain the hyperbranched butyl rubber product. Sampling and analyzing: standard test specimens were prepared and the test properties are shown in Table 1.

TABLE 1 Properties of the hyperbranched butyl rubbers

As can be seen from Table 1: the hyperbranched butyl rubber has ultrahigh branching degree and ultra-wide molecular weight distribution, so that the Mooney relaxation area is small, and the hyperbranched butyl rubber has good air tightness and high tensile strength, which shows that the hyperbranched butyl rubber has excellent physical and mechanical properties and good processability.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that all such changes and modifications as fall within the true spirit and scope of the invention be considered as within the following claims.