Preparation method of three-arm brominated branched butyl rubber

Abstract

The invention discloses a kind of preparation method of three miscellaneous arm brominated branched butyl rubber, the preparation method includes adding polymer three miscellaneous arm brominated grafting agent in a mixed solvent, is sufficiently stirred until polymer three miscellaneous arm brominated grafting agent is completely dissolved, obtains a mixed solution;Cooling, diluent, isobutylene and isoprene are sequentially added into a mixed solution, is sufficiently stirred and mixed, obtains a polymerization reaction system, cools the temperature again;Diluent and co-initiator are mixed and aged, then added into the polymerization reaction system and fully stirred after reaction, terminator is added, discharging condenses, washes, dries, and obtains three miscellaneous arm brominated branched butyl rubber;Polymer three miscellaneous arm brominated grafting agent is a kind of three miscellaneous arm brominated star block copolymers consisting of isoprene, 1,3-butadiene, styrene and macromolecular composite brominating agent.The preparation method of the present invention enables butyl rubber to maintain enough green rubber strength and good air tightness, imparts the balance of physical and mechanical properties and vulcanization processability.

Description

Technical Field

[0001] The present invention relates to a method for preparing a three-arm brominated branched butyl rubber, and in particular to a method for preparing the three-arm brominated branched butyl rubber by grafting and modifying an isoprene / butadiene / styrene three-arm star block copolymer brominated at primary and secondary positions. Background Art

[0002] Butyl rubber (IIR) is a cationic copolymer of isobutylene and a small amount of isoprene. It exhibits excellent air tightness, damping properties, heat aging resistance, ozone resistance, and weather resistance, making it widely used in the manufacture of inner tubes, airtight layers, and vulcanizing bladders for automotive tires, making it one of the most important synthetic rubbers. However, the butyl rubber molecular chain is primarily composed of carbon-carbon single bonds, has a low degree of unsaturation, and has symmetrically arranged methyl substituents. This leads to high crystallinity, poor molecular chain flexibility, slow stress release and vulcanization rates, poor adhesion, and poor compatibility with other general-purpose rubbers. Consequently, butyl rubber is prone to excessive flow and deformation during processing, which has become a bottleneck in the expansion of butyl rubber's application.

[0003] Currently, brominated butyl rubber (BIIR) is produced by introducing bromine atoms into the molecular chain of butyl rubber (IIR) through an electrophilic substitution reaction under the action of molecular bromine. Compared to IIR, BIIR not only has the same excellent airtightness, but the introduction of bromine atoms not only increases the polarity of the molecular chain, improving adhesion to other rubbers, and can be used in any ratio with unsaturated rubbers such as natural rubber and styrene-butadiene rubber, but also creates additional crosslinking sites, enhancing the activity of the original double bonds, improving the vulcanization properties of the rubber, faster vulcanization speed, more diverse vulcanization methods, and increased heat resistance. Therefore, BIIR is gradually replacing IIR in industrial products such as radial tires, tubeless tires, medical sealing equipment, and chemical equipment linings, and has broad industrial application value and prospects.

[0004] In recent years, researchers have discovered a star-branched butyl rubber composed of high-molecular-weight branched structures and low-molecular-weight linear structures. This star-branched butyl rubber can be brominated to produce brominated star-branched butyl rubber. This brominated star-branched butyl rubber, due to its unique "three-dimensional network" branching structure and bromine atoms, possesses a wide molecular weight distribution and excellent viscoelastic properties, as well as high green strength and a fast cure rate. In particular, during processing, it exhibits low melt viscosity, low processing energy consumption, low binder removal temperature, low shrinkage, and long scorch time. This balance of physical and mechanical properties and processing performance is achieved in brominated star-branched butyl rubber. Therefore, brominated star-branched butyl rubber has become a hot topic in the future butyl rubber research.

[0005] CN112574333A provides a bromination process for star-branched butyl rubber, which comprises: a) dissolving the star-branched butyl rubber in an aliphatic hydrocarbon to obtain a rubber solution; b) mixing the above-mentioned rubber solution with a branching agent and a scavenger ethanol to obtain a mixed solution; c) adding an oxidizing agent, hydrogen peroxide, and a brominating agent, Br2, to the above-mentioned mixed solution, wherein the molar ratio of bromine element to unsaturated double bonds in the star-branched butyl rubber is Bromination reaction, final neutralization, and product recovery are performed to obtain brominated star-branched butyl rubber. This process can dissolve the residual branching agent in the star-branched butyl rubber before bromination, preventing it from combining with the HBr byproduct generated during the bromination process, thereby improving neutralization efficiency and inhibiting the isomerization transformation of Type II secondary structure to Type III primary structure.

[0006] CN112011019A discloses a method for preparing a halogenated bimodal star-branched butyl rubber. The method uses anionic polymerization technology to synthesize a poly(styrene-conjugated diene) block polymer, which is then coupled with silicon tetrachloride to obtain a four-arm star-shaped block polymer. After dissolving the copolymer, HCl gas is continuously introduced at -20 to 0°C for 3 to 12 hours to obtain a functionalized four-arm star-shaped branching agent containing silicon and chlorine. The functionalized four-arm star-shaped branching agent containing silicon and chlorine is dissolved in a solvent, isobutylene and isoprene are added, the temperature is lowered to below -60°C, a primary initiator and a co-initiator are mixed and aged, and then added to the system. The mixture is polymerized under stirring for 3 to 30 minutes, a terminator is added to terminate the reaction, the mixture is steamed under reduced pressure, and the sample is vacuum dried. The rubber is then halogenated to obtain a halogenated bimodal star-shaped branched butyl rubber. The bimodal star-shaped branched butyl rubber prepared by this method has the characteristics of low Mooney stress relaxation and lower intrinsic viscosity, and exhibits good processing properties.

[0007] CN 101353403B discloses a method for preparing star-branched polyisobutylene or butyl rubber. The method adopts a polystyrene / isoprene block copolymer containing a silyl chloride group at the end or a polystyrene / butadiene block copolymer containing a silyl chloride group at the end as an initiator-grafting agent for cationic polymerization. The method directly participates in cationic polymerization in a cationic polymerization system containing a mixed solvent of monochloromethane / cyclohexane with a v:v ratio of 20-80 / 80-20 at a temperature of 0-100°C. The star-branched polyisobutylene or butyl rubber product is prepared by the cationic polymerization initiated by the silyl chloride group and the grafting reaction of unsaturated chains.

[0008] CN 106749816A discloses a method for preparing brominated butyl rubber. The method first dissolves the butyl rubber in n-alkanes, then uses a specific organic bromide, such as phenyltrimethylammonium tribromide, benzyltrimethylammonium tribromide, or dibromoisocyanuric acid, as a brominating agent, and Br2 or HBr as a bromination accelerator in a solvent to carry out a bromination reaction to obtain brominated butyl rubber. This method inhibits the molecular rearrangement of secondary bromine in the brominated butyl rubber to form tertiary bromine, thereby increasing the content of secondary bromine structures in the brominated butyl rubber.

[0009] Wu Yibo et al. (Davang SH, et al. Skid resistant coatings for aircraft carrier decks [J]. Coat Technol, 1980, 52 (671): 65-69.) disclosed a method of preparing a poly (isoprene-styrene) block copolymer as a grafting agent by living anionic polymerization, and preparing a star-branched butyl rubber showing obvious bimodal properties by living carbocationic polymerization in an initiation system of 2-chloro-2,4,4-trimethylpentane / titanium tetrachloride / proton scavenger.

[0010] Synthetic Rubber Industry (2006, 29(4): A method for preparing brominated butyl rubber (Polysar-301) by dissolving it in cycloalkanes and brominating it with liquid bromine is disclosed. The effects of residence time and reaction temperature on the Mooney viscosity, unsaturation, bromine content, and microstructure of the product were investigated. The results showed that the Mooney viscosity and unsaturation decreased sharply when the residence time was less than 2 minutes, but remained largely unchanged after 2 minutes. Increasing the reaction temperature decreased the Mooney viscosity while having little effect on the unsaturation. Increasing the reaction temperature and residence time not only increased the bromine content of the product but also promoted a rearrangement of its molecular structure, namely, a shift from a secondary allylic bromide configuration to a more stable primary allylic bromide configuration.

[0011] In the above-mentioned prior art, the brominated butyl rubber obtained by dissolving and brominating star-branched butyl rubber or butyl rubber exhibits a larger molecular weight distribution, increased stress relaxation rate, faster vulcanization speed, and excellent processability. However, these methods still have certain limitations. During the bromination of butyl rubber, hydrogen bromide is easily generated as a byproduct, resulting in loss of the remaining bromine, reducing bromine utilization and significantly isomerizing the Type II secondary structure of the brominated butyl rubber to the Type III primary structure, thereby affecting the processability of the brominated butyl rubber. Furthermore, hydrogen bromide is highly corrosive, resulting in deterioration of the quality of the brominated butyl rubber and potentially causing environmental pollution and human health issues. Summary of the Invention

[0012] The present invention aims to provide a method for preparing a three-arm brominated branched butyl rubber. This method uses a macromolecular composite brominating agent as a raw material, and the macromolecular composite brominating agent has anionic reactivity. Secondly, a high-molecular-weight three-arm brominated grafting agent having a high-width distribution, primary and secondary bromine structures, and a three-arm structure is prepared through a three-pot reaction using reactive monomers: isoprene, styrene, butadiene, the macromolecular composite brominating agent, and a coupling agent. Finally, a high-width distribution brominated branched butyl rubber is prepared through cationic polymerization using the high-molecular-weight three-arm brominated grafting agent, isobutylene, and isoprene as reactive monomers. This method prepares butyl rubber with both secondary and primary bromine structures through polyaddition reaction, avoids rearrangement of the bromine structure, solves the problem of bromine structure stability in the brominated branched butyl rubber, and significantly increases the vulcanization rate of the butyl rubber while ensuring scorch safety during the vulcanization process and improving vulcanization efficiency. At the same time, a high and wide molecular weight distribution of butyl rubber is achieved, which not only solves the problem of slow stress relaxation rate of butyl rubber during processing, but also maintains sufficient raw rubber strength and good air tightness of butyl rubber, achieving a balance between the physical and mechanical properties and processing performance of butyl rubber.

[0013] Unless otherwise specified, the "%" mentioned in the present invention refers to mass percentage.

[0014] To achieve the above object, the present invention provides a method for preparing a three-arm brominated branched butyl rubber, the preparation method comprising the following steps:

[0015] S1: adding a high molecular weight three-arm brominated grafting agent to a mixed solvent, and stirring thoroughly until the high molecular weight three-arm brominated grafting agent is completely dissolved to obtain a mixed solution;

[0016] S2: Cooling the mixture, sequentially adding a diluent, isobutylene, and isoprene to the mixed solution of step S1, stirring and mixing the mixture to obtain a polymerization reaction system, and cooling the mixture again;

[0017] S3: mixing the diluent and the co-initiator and aging them, then adding them to the polymerization reaction system of step S2, stirring them thoroughly for reaction, adding a terminator, coagulating the discharged material, washing, and drying it to obtain a three-arm brominated branched butyl rubber;

[0018] The invention is characterized in that the high molecular weight three-arm brominated grafting agent is a three-arm brominated star block copolymer composed of isoprene, 1,3-butadiene, styrene and a macromolecular composite brominating agent, and its general structural formula is shown in Formula I:

[0019]

[0020] Among them, IR is an isoprene homopolymer block; PS is a styrene homopolymer segment; SBR is a random segment of styrene and 1,3-butadiene; B is a terminal 1,3-butadiene small molecule chain segment; the macromolecular composite brominating agent is a random block copolymer of 1,2-dibromoethylene, cis-2-methyl-1,4-dibromo-2-butene and 1,3-butadiene; m and n are the number of repeating units, m is an integer ≥1, and n is an integer ≥1; the number average molecular weight (Mn) of the polymer three-arm brominated grafting agent is 50,000 to 70,000, and the molecular weight distribution (Mw / Mn) is 9.27 to 11.14.

[0021] In the preparation method of the three-arm brominated branched butyl rubber of the present invention, in step S1, the mass ratio of the mixed solvent to the high molecular weight three-arm brominated grafting agent is 100-200:6-9.

[0022] In the preparation method of the three-arm brominated branched butyl rubber of the present invention, in step S1, the mixed solvent includes a diluent and a solvent, and the volume ratio of the diluent to the solvent is 60-40 / 40-60.

[0023] In the preparation method of the three-arm brominated branched butyl rubber of the present invention, in step S2, the temperature is lowered to -80 to -90°C.

[0024] In the method for preparing the three-arm brominated branched butyl rubber of the present invention, in step S2, the mass ratio of the diluent, isobutylene and isoprene is 100-200:85-90:4-6.

[0025] In the preparation method of the three-arm brominated branched butyl rubber of the present invention, in step S2, the temperature is lowered again to a temperature of -100 to -90°C.

[0026] In the method for preparing the three-arm brominated branched butyl rubber of the present invention, in step S3, the mass ratio of the diluent, the co-initiator and the terminator is 20-30:0.3-0.7:5-10.

[0027] In the preparation method of the three-arm brominated branched butyl rubber of the present invention, in step S3, the aging temperature is -95°C to -85°C, and the aging time is 50 to 60 minutes.

[0028] The preparation method of the three-arm brominated branched butyl rubber of the present invention specifically comprises the following steps:

[0029] a. Preparation of a macromolecular composite brominating agent: first, based on 100 parts by mass of the reactive brominating agent, add 200-300 parts of solvent, 80-90 parts of 1,2-dibromoethylene, 10-20 parts of cis-2-methyl-1,4-dibromo-2-butene, and 0.1-0.4 parts of a molecular weight regulator to a reactor replaced with inert gas, stir and mix, and heat. When the temperature of the reactor reaches 50-70° C., add 0.1-0.5 parts of a first initiator and react for 3.0-5.0 hours, at which time the conversion of 1,2-dibromoethylene reaches 100%. Then, add 1-3 parts of 1,3-butadiene to the reactor for end-capping, and react for 40-50 minutes until no free monomer is present. After the reaction is completed, wash and dry to obtain a macromolecular composite brominating agent.

[0030] b. Preparation of a high molecular weight three-arm brominated grafting agent: first, based on 100% of the total weight of the reaction monomers, add 100wt% to 200wt% of solvent, 10wt% to 20wt% of isoprene, 0.1wt% to 0.3wt% of a structure regulator, and a second initiator to a reactor A after inert gas replacement, raise the temperature to 50 to 60°C, react for 30 to 50 minutes to form an -IR- segment, then add 10wt% to 20wt% of a macromolecular composite brominating agent to the reactor A, react for 50 to 80 minutes until no free monomers are present; simultaneously, add 100wt% to 200wt% of solvent, 5wt% to 10wt% of styrene, 10wt% to 20wt% of 1,3-butadiene, 0.2wt% to 0.5wt% of a structure regulator, and a second initiator to a reactor B after inert gas replacement, raise the temperature to 60 to 70°C, react for 50 to 70 minutes to form an -SBR- segment, and then Then, 20 wt% to 25 wt% of a macromolecular composite brominating agent is added to reactor B, and the reaction is carried out for 70 to 90 minutes until no free monomers are present. Then, the materials in reactor B are added to reactor A. Simultaneously, 100 wt% to 200 wt% of a solvent, 10 wt% to 20 wt% of styrene, 0.1 wt% to 0.3 wt% of a structure regulator, and a second initiator are added to reactor C after inert gas replacement. The temperature is raised to 60 to 70° C., and the reaction is carried out for 30 to 50 minutes. Then, 1 to 3 wt% of 1,3-butadiene is added for end-capping, and the reaction is carried out for 20 to 30 minutes to form -PS-B- segments until no free monomers are present. Then, the materials in reactor C are added to reactor A. Finally, the temperature of reactor A is raised to 80 to 90° C., a coupling agent is added for coupling reaction, and the reaction mixture after reaction is treated with water. The reaction mixture is subjected to wet coagulation and drying to obtain a macromolecular tri-arm bromination grafting agent.

[0031] In the preparation method of the three-arm brominated branched butyl rubber of the present invention, the molecular weight regulator can be selected from at least one of tert-decyl mercaptan, tert-dodecyl mercaptan, tert-tetradecyl mercaptan, and tert-hexadecyl mercaptan, preferably tert-dodecyl mercaptan.

[0032] The preparation method of the three-arm brominated branched butyl rubber of the present invention, wherein the first initiator is an organic peroxide, selected from at least one of 1,1-dimethylethyl peroxide, 1,1-dimethylethyl-1-methyl-1-[3-(1-methylvinyl)phenyl]ethyl peroxide, tert-butyl peroxide, di-tert-butyl peroxide (DTBP) and tert-amyl oxide (DTAP), preferably di-tert-butyl peroxide (DTBP).

[0033] The method for preparing a three-arm brominated branched butyl rubber of the present invention comprises a structure regulator which is a polar organic compound that produces a solvation effect in the polymerization system and can regulate the reactivity ratio of styrene and isoprene, thereby causing the two to copolymerize randomly. The polar organic compound is selected from the group consisting of diethylene glycol dimethyl ether (DGE), tetrahydrofuran (THF), ethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME), and triethylamine, preferably tetrahydrofuran (THF).

[0034] In the method for preparing a three-arm brominated branched butyl rubber of the present invention, the second initiator is a hydrocarbon monolithium compound, namely, RLi, where R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, or a composite of the foregoing groups containing 1 to 20 carbon atoms. The hydrocarbon monolithium compound is selected from at least one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium, and dodecyllithium, preferably n-butyllithium. The amount of the second initiator added is determined by the molecular weight of the designed polymer.

[0035] In the method for preparing a tri-arm brominated branched butyl rubber of the present invention, the coupling agent is at least one of 1,3,5-trichlorobenzene and 1,3,5-tribromobenzene, preferably 1,3,5-trichlorobenzene. The amount of the coupling agent used depends on the amount of the second initiator, and the molar ratio of the coupling agent to the second initiator is 1:1 to 5:1.

[0036] The polymerization reaction in the method for preparing the three-arm brominated branched butyl rubber of the present invention is carried out in an oxygen-free and water-free environment, preferably in an inert gas environment. The polymerization reaction and dissolution process are both carried out in a hydrocarbon solvent. The solvent of the present invention is a hydrocarbon solvent, which includes linear alkanes, aromatic hydrocarbons, and cycloalkanes. The hydrocarbon solvent is selected from at least one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene, and ethylbenzene, with heptane being preferred.

[0037] In the method for preparing a three-arm brominated branched butyl rubber of the present invention, the diluent is a halogenated alkane, wherein the halogen atoms in the halogenated alkane may be chlorine, bromine, or fluorine; and the number of carbon atoms in the halogenated alkane is C1-C4. The halogenated alkane is selected from at least one of monochloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, monofluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane, preferably monochloromethane.

[0038] The present invention provides a method for preparing a three-arm brominated branched butyl rubber. The co-initiator comprises an alkyl aluminum halide and a protonic acid compounded in different proportions. The alkyl aluminum halide is selected from at least one of diethylaluminum monochloride, diisobutylaluminum monochloride, methylaluminum dichloride, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, n-propylaluminum dichloride, isopropylaluminum dichloride, dimethylaluminum chloride, and ethylaluminum chloride, preferably sesquiethylaluminum chloride. The protonic acid is selected from at least one of HCl, HF, HBr, H2SO4, H2CO3, H3PO4, and HNO3, preferably HCl. The molar ratio of the protonic acid to the alkyl aluminum halide is 0.05:1 to 0.5:1.

[0039] In the preparation method of the three-arm brominated branched butyl rubber of the present invention, the terminator is, for example but not limited to, at least one of methanol, ethanol, and butanol.

[0040] The present invention can also be described in detail as follows:

[0041] In detail, the specific preparation process of the preparation method of the three-arm brominated branched butyl rubber of the present invention comprises the following steps:

[0042] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0043] a. Preparation of a macromolecular composite brominating agent: Based on 100 parts by mass of the reactive brominating agent, first, in a 15L stainless steel reactor with a jacket, the inert gas is replaced 2 to 4 times, and 200 to 300 parts of solvent, 80 to 90 parts of 1,2-dibromoethylene, 10 to 20 parts of cis-2-methyl-1,4-dibromo-2-butene, and 0.1 to 0.4 parts of a molecular weight regulator are added to the reactor in sequence, mixed, and heated. When the temperature of the reactor reaches 50 to 70°C, 0.1 to 0.5 parts of a first initiator are added and the reaction is carried out for 3.0 to 5.0 hours, at which time the conversion of 1,2-dibromoethylene reaches 100%; then 1 to 3 parts of 1,3-butadiene are added to the reactor for end-capping, and the reaction is carried out for 40 to 50 minutes until no free monomer is present. After the reaction is completed, the reaction is washed and dried to obtain a macromolecular composite brominating agent.

[0044] b. Preparation of high molecular weight tri-arm brominated grafting agent: Based on 100% of the total weight of the reaction monomers, first, in a 15L stainless steel reactor A with a jacket, argon gas was replaced 2 to 4 times, and 100wt% to 200wt% of solvent, 10wt% to 2wt% of 0% isoprene, 0.1wt%-0.3wt% structure regulator, second initiator, heating to 50-60°C, reacting for 30-50 minutes to form -IR- segments, then adding 10wt%-20wt% macromolecular composite brominating agent to reactor A, reacting for 50-80 minutes until no free monomers are present; at the same time, in a 15L stainless steel reactor B, argon is passed through the system to replace 2-4 times, and 100wt%-200wt% solvent, 5wt%-10wt% of styrene, 10wt%-20wt% of 1,3-butadiene, 0.2wt%-0.5wt% of structure regulator, second initiator are added in sequence, heating to 60-70°C, reacting for 50-70 minutes to form -SBR- segments, then adding 20wt%-25wt% macromolecular composite brominating agent to reactor B, reacting for 70-90 minutes, The reaction mixture is stirred until no free monomers are present, and then the materials in reactor B are added to reactor A. Meanwhile, in a 15L stainless steel reactor C, argon is introduced to replace the system 2 to 4 times, and 100 wt% to 200 wt% of a solvent, 10 wt% to 20 wt% of styrene, 0.1 wt% to 0.3 wt% of a structure regulator, and a second initiator are added in sequence. The temperature is raised to 60 to 70°C, and the reaction is carried out for 30 to 50 minutes. Then, 1 to 3 wt% of 1,3-butadiene is added for end-capping, and the reaction is carried out for 20 to 30 minutes to form -PS-B- segments. The reaction mixture is stirred until no free monomers are present, and then the materials in reactor C are added to reactor A. Finally, the temperature of reactor A is raised to 80 to 90°C, a coupling agent is added for coupling reaction, and the reaction mixture is treated with water after the coupling reaction. The gel is subjected to wet coagulation and drying to obtain a high molecular weight three-arm brominated grafting agent.

[0045] (2) Preparation of tri-arm brominated branched butyl rubber: Based on 100% of the total mass of the reaction monomers, first, in a 4L stainless steel reactor with a jacket, nitrogen is replaced 3 to 5 times, 100wt% to 200wt% of a mixed solvent (diluent / solvent V:V ratio is 60 to 40 / 40 to 60) and 6wt% to 9wt% of a high molecular weight tri-arm brominated grafting agent are added to the reactor, and stirred and dissolved for 90 to 100 minutes until the grafting agent is completely dissolved; then, when the temperature is lowered to -80 to -90°C, 100wt% to 200wt% of a diluent and 6wt% to 9wt% of a high molecular weight tri-arm brominated grafting agent are added in sequence. The invention discloses a method for preparing a tri-arm brominated branched butyl rubber product comprising the steps of: preparing a diluent, 85 wt% to 90 wt% isobutylene, and 4 wt% to 6 wt% isoprene, and stirring and mixing the mixture until the temperature of the polymerization system drops to -100 to -90°C; then, mixing and aging 20 wt% to 30 wt% of a diluent and 0.3 wt% to 0.7 wt% of a co-initiator at -95 to -85°C for 50 to 60 minutes, and then adding the mixture to the polymerization system, stirring and reacting for 5.0 to 7.0 hours; and finally, adding 5 wt% to 10 wt% of a terminator, and the discharged material is condensed, washed, and dried to obtain a tri-arm brominated branched butyl rubber product.

[0046] The high molecular weight three-arm brominated grafting agent of the present invention is a three-arm brominated star block copolymer composed of isoprene, 1,3-butadiene, styrene and a macromolecular composite brominating agent, and its general structural formula is shown in Formula I:

[0047]

[0048] The polymer comprises an isoprene homopolymer block; PS is a styrene homopolymer segment; SBR is a random segment of styrene and 1,3-butadiene; B is a small end-capped 1,3-butadiene chain segment; and the macromolecular composite brominating agent is a random block copolymer of 1,2-dibromoethylene, cis-2-methyl-1,4-dibromo-2-butene, and 1,3-butadiene. m and n represent the number of repeating units. The polymeric tri-arm brominated grafting agent has a number average molecular weight (Mn) of 50,000 to 70,000 and a molecular weight distribution (Mw / Mn) of 9.27 to 11.14.

[0049] The invention firstly performs free radical polymerization on 1,2-dibromoethylene and cis-2-methyl-1,4-dibromo-2-butene to generate a macromolecular composite brominating agent, and then uses 1,3-butadiene for end-capping activation to prepare a macromolecular composite brominating agent with anionic reaction activity; secondly, isoprene, styrene, 1,3-butadiene and the macromolecular composite brominating agent form reaction monomers, and a three-pot reaction is carried out, and finally a trihalogenated benzene coupling agent is used for coupling to prepare a high molecular weight three-arm brominated grafting agent; finally, the high molecular weight three-arm brominated grafting agent, isobutylene and isoprene are used as reaction monomers to prepare a high-width distribution brominated branched butyl rubber containing secondary and primary bromine structures through cationic polymerization.

[0050] The preparation of the high molecular weight three-arm brominated grafting agent of the present invention adopts free radical polymerization and anionic polymerization instead of the ion substitution reaction in the prior art, thereby avoiding the rearrangement of the bromine structure in the brominated branched butyl rubber, improving the stability of the secondary bromine structure in the brominated branched butyl rubber, and greatly improving the vulcanization speed of the butyl rubber while ensuring the safety of the scorch time of the butyl rubber, thereby ensuring the vulcanization efficiency and the quality of the vulcanized rubber. Secondly, this high molecular weight three-arm brominated grafting agent adopts three-pot polymerization to obtain a three-arm star-branched structure. This structure combines three chain segments with different microstructures on a large molecular chain to form a three-arm star structure. Due to the different reactivity ratios and spatial steric effects of each chain segment, the disorder of the molecular chain segments increases and the regularity of the molecular chain is significantly destroyed during the grafting polymerization of butyl rubber, so that the molecular weight distribution is significantly broadened, ensuring that the butyl rubber can obtain good viscoelastic properties, have a fast stress relaxation rate, and improve the processing performance of butyl rubber; finally, the IR segment and SBR segment in the high molecular weight three-arm brominated grafting agent contain a large number of benzene rings, which avoids the decrease in strength and air tightness due to the broadening of the molecular weight distribution of butyl rubber, thereby ensuring that the butyl rubber has high strength and good air tightness.

[0051] Therefore, the polymer three-arm brominated grafting agent of the present invention organically combines the primary and secondary bromine structures, the three-arm star-branched structure, the IR segment, the SBR segment and the PS segment and works synergistically, thereby resolving the contradictory relationship between the poor vulcanization characteristics and processability of butyl rubber and its good physical and mechanical properties, achieving a balance among the vulcanization characteristics, processability, strength and air tightness of butyl rubber, and more comprehensively improving the performance of butyl rubber.

[0052] In summary, the present invention has the following beneficial effects:

[0053] 1. The polymer three-arm brominated grafting agent of the present invention adopts free radical polymerization and anionic polymerization instead of the ion substitution reaction in the prior art, thereby avoiding the rearrangement of the bromine structure in the brominated branched butyl rubber, improving the stability of the secondary bromine structure in the brominated branched butyl rubber, and greatly improving the vulcanization speed of butyl rubber while ensuring the safety of the scorch time of butyl rubber, thereby ensuring the vulcanization efficiency and the quality of the vulcanized rubber.

[0054] 2. The macromolecular brominated grafting agent of the present invention first undergoes free radical polymerization with an organic brominating agent containing an unsaturated double bond to generate a macromolecular brominating agent, which then participates in an anion reaction. During the entire reaction process, no HBr is generated, thereby avoiding the loss of remaining bromine, increasing the reaction degree of the organic brominating agent, and improving the utilization rate of the bromine element in the brominated branched butyl rubber.

[0055] 3. The high molecular weight three-arm wide distribution brominated grafting agent of the present invention does not generate by-product HBr during the entire reaction process, reducing the harm to humans and the environment, eliminating the alkali washing and recovery process of the by-product HBr, thereby shortening the process and reducing production costs.

[0056] 4. The polymer three-arm brominated grafting agent of the present invention adopts three-pot polymerization to obtain a three-arm star-branched structure. This structure organically combines the primary and secondary bromine structures, the three-arm star-branched structure, the IR segment, the SBR segment and the PS segment to form a three-arm star structure. Due to the different reactivity ratios and steric hindrance effects of each segment, the disorder of the molecular segments increases and the regularity of the molecular chain is significantly destroyed during the graft polymerization of butyl rubber, so that the molecular weight distribution is significantly broadened, ensuring that the butyl rubber can obtain good viscoelastic properties and have a fast stress relaxation rate, so that the butyl rubber obtains excellent processability, while ensuring that the butyl rubber has high strength and good air tightness, achieving a balance between the vulcanization characteristics and processability of butyl rubber and the strength and air tightness.

[0057] 5. The polymer three-arm brominated grafting agent of the present invention is a new type of safe and environmentally friendly compound that does not emit atmospheric pollutants (VOCs) and by-product HBr. Its preparation method is green and environmentally friendly, the process flow is short, the bromine structure is stable, the processing performance is excellent, and it is suitable for industrial production. DETAILED DESCRIPTION

[0058] The following is a detailed description of the embodiments of the present invention: This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and processes. However, the protection scope of the present invention is not limited to the following embodiments. The experimental methods in the following embodiments where specific conditions are not specified are generally based on conventional conditions.

[0059] (1) Source of raw materials:

[0060] Styrene, 1,3-butadiene, polymer grade, PetroChina Lanzhou Petrochemical Company;

[0061] Isobutylene, isoprene, polymer grade Zhejiang Xinhui New Materials Co., Ltd.;

[0062] cis-2-methyl-1,4-dibromo-2-butene, polymer grade, Shanghai Yishi Chemical Co., Ltd.;

[0063] 1,2-Dibromoethylene, polymer grade Shanghai Yishi Chemical Co., Ltd.;

[0064] Tert-butyl peroxide (DTBP), Lanzhou Additive Factory;

[0065] n-Butyl lithium, 98% purity, Nanjing Tonglian Chemical Co., Ltd.;

[0066] 1,3,5-Trichlorobenzene, purity 99%, Yangzhou Haichen Chemical Co., Ltd.;

[0067] Ethyl aluminum chloride, purity 98%, J&K Technology Co., Ltd.;

[0068] Other reagents are commercially available products.

[0069] (2) Analytical testing methods:

[0070] Bromine content determination: Weigh 10 mg of sample and thermally degrade the sample using a Q600 TG / DTG thermogravimetric analyzer at a heating rate of 10°C / min in a nitrogen atmosphere at a flow rate of 50 mL / min. The first stage of thermal degradation is the debromination of bromine-containing units in the sample to form HBr. The bromine content (X) in the sample is then inferred from the percentage of HBr removed using the following formula:

[0071]

[0072] Where: Y is the percentage of the sample at 220°C; 79.904 is the relative atomic mass of bromine; 1.008 is the relative atomic mass of hydrogen.

[0073] Molecular weight and distribution were determined using a 2414 gel permeation chromatograph (GPC) produced by Waters, USA. Polystyrene standards were used as the calibration curve, the mobile phase was tetrahydrofuran, the column temperature was 40°C, the sample concentration was 1 mg / mL, the injection volume was 50 μL, the elution time was 40 min, and the flow rate was 1 mL min. -1 .

[0074] Mooney stress relaxation was determined using a GT-7080S2 Mooney viscometer, using a large rotor at 125°C (1+8°C) according to the method described in GB / T 1232.1-2000. Stress relaxation was determined by rapidly stopping the rotor (within 0.1 second) after the Mooney viscosity test and recording the Mooney viscosity decay over time. The torque within 0.1 second of rotor cessation was set as 100%, and the stress relaxation behavior of the rubber was expressed as t80 (the time it takes for the torque to decay by 80% (remaining 20%)) and X30 (the percentage of torque remaining 30 seconds after the rotor stopped).

[0075] Vulcanization characteristics: tested according to GB / T 16584-1996.

[0076] Air tightness test: Use an automated air tightness tester to measure the air permeability according to ISO 2782:1995.

[0077] The test gas is N2, the test temperature is 23°C, and the test sample is a circular sea piece with a diameter of 8 cm and a thickness of 1 mm.

[0078] Tensile strength: Execute the method in standard GB / T528-2009.

[0079] Example 1

[0080] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0081] Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen was replaced twice, and 2000g of heptane, 800g of 1,2-dibromoethylene, 200g of cis-2-methyl-1,4-dibromo-2-butene, and 1.0g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 50°C, 1.0g of DTBP was added and the reaction was carried out for 3.0 hours. Then, 10g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 40 minutes until no free monomer was present. After the reaction was completed, the mixture was washed and dried to obtain a macromolecular composite brominating agent.

[0082] b. Preparation of high molecular weight three-arm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for replacement twice, and 1000g of heptane, 200g of isoprene, and 1.0g of THF were added to the polymerization reactor in sequence. The temperature was raised to 50°C, and 10.3mmol of n-butyl lithium was added to start the reaction for 30min to form -IR- segments. Then, 100g of macromolecular composite brominating agent was added to the polymerization reactor A and the reaction was continued for 50min until no free monomers were present. At the same time, in a 15L stainless steel polymerization reactor B, argon was passed through the system for replacement twice, and 1000g of heptane, 50g of styrene, 200g of 1,3-butadiene, 2.0g of THF, heated to 60 ° C, added 15.3 mmol n-butyl lithium to start the reaction for 50 minutes to form -SBR- segments, and then added 200 g of macromolecular composite brominating agent to polymerization kettle B, reacted for 70 minutes until no free monomers were present, and then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in a 15L stainless steel polymerization kettle C, argon was passed through the system to replace it twice, and 1000 g of heptane, 100 g of styrene, and 1.0 g of THF were added in sequence, heated to 60 ° C, 6.3 mmol n-butyl lithium was added to start the reaction for 30 minutes, and then 10 g of 1,3-butadiene was capped and the reaction was continued for 20 minutes to form -PS-B- segments; until no free monomers were present, the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 80°C, 40.7 mmol 1,3,5-trichlorobenzene was added and the reaction was continued for 70 minutes, and then the reaction mixture after coupling was treated with water. The gel was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent (Mn was 51000, Mw / Mn was 9.27).

[0083] (2) Preparation of tri-arm brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen was purged three times. 300g of chloromethane, 200g of cyclohexane, and 30.0g of a high molecular weight tri-arm brominated grafting agent were added to the reactor and stirred for 90 minutes until they were completely dissolved. Then, when the temperature was lowered to 80°C, 500g of chloromethane, 450g of isobutylene, and 20g of isoprene were added in sequence and stirred until the polymerization system temperature dropped to -90°C. Then, 100g of chloromethane, 1.49g of sesquiethylaluminum chloride, and 0.032g of HCl were mixed and aged at -85°C for 50 minutes. The mixture was then added to the polymerization system and stirred for 5.0 hours. Finally, 25g of methanol was added, the material was discharged, condensed, washed, and dried to obtain a tri-arm brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared. The test properties are shown in Table 1.

[0084] Example 2

[0085] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0086] a. Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen was replaced twice, and 2300g of heptane, 810g of 1,2-dibromoethylene, 190g of cis-2-methyl-1,4-dibromo-2-butene, and 1.5g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 55°C, 1.5g of DTBP was added and the reaction was carried out for 3.5 hours. Then, 15g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 42 minutes until no free monomer was present. After the reaction was completed, the reaction was washed and dried to obtain a macromolecular composite brominating agent.

[0087] b. Preparation of high molecular weight three-arm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for replacement twice, and 1200g of heptane, 180g of isoprene, and 1.2g of THF were added to the polymerization reactor in sequence. The temperature was raised to 52°C, and 11.3mmol of n-butyl lithium was added to start the reaction for 35min to form -IR- segments. Then, 110g of the macromolecular composite brominating agent was added to the polymerization reactor A and the reaction was continued for 55min until no free monomers were present. At the same time, in a 15L stainless steel polymerization reactor B, argon was passed through the system for replacement twice, and 1100g of heptane, 60g of styrene, 180g of 1,3-butadiene, 2.5g of THF, heated to 62 ° C, added 16.5 mmol n-butyl lithium to start the reaction for 53 minutes to form -SBR- segments, and then added 210 g of macromolecular composite brominating agent to polymerization kettle B, and reacted for 75 minutes until no free monomers were present. Then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in 15L stainless steel polymerization kettle C, argon was passed through the system to replace it twice, and 1200 g of heptane, 120 g of styrene, 1.3 g of THF, heated to 62°C, 8.3 mmol n-butyl lithium was added to start the reaction for 35 minutes, and then 15 g 1,3-butadiene was added for end-capping, and the reaction was carried out for 22 minutes to form -PS-B- segments; until no free monomers were present, and then the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 82°C, 50.7 mmol 1,3,5-trichlorobenzene was added, and the reaction was carried out for 73 minutes, and then the reaction mixture after coupling was treated with water. The glue was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent (Mn was 56000, Mw / Mn was 9.85).

[0088] (2) Preparation of tri-arm brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen was purged three times. 200g of chloromethane, 300g of cyclohexane, and 32.0g of a high molecular weight tri-arm brominated grafting agent were added to the reactor and stirred for 92 minutes until they were completely dissolved. Then, when the temperature was lowered to -80°C, 600g of chloromethane, 446g of isobutylene, and 22g of isoprene were added in sequence and stirred until the polymerization system temperature dropped to -92°C. Then, 110g of chloromethane, 1.67g of sesquiethylaluminum chloride, and 0.051g of HCl were mixed and aged at -87°C for 52 minutes. The mixture was then added to the polymerization system and stirred for 5.5 hours. Finally, 30g of methanol was added. The product was discharged, condensed, washed, and dried to obtain a tri-arm brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared. The test properties are shown in Table 1.

[0089] Example 3

[0090] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0091] Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen was replaced three times, and 2500g of heptane, 840g of 1,2-dibromoethylene, 160g of cis-2-methyl-1,4-dibromo-2-butene, and 2.0g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 60°C, 2.0g of DTBP was added and the reaction was carried out for 4.0 hours. Then, 20g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 44 minutes until no free monomer was present. After the reaction was completed, the reaction was washed and dried to obtain a macromolecular composite brominating agent.

[0092] b. Preparation of high molecular weight three-arm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for replacement three times, and 1500g of heptane, 160g of isoprene, and 1.8g of THF were added to the polymerization reactor in sequence. The temperature was raised to 54°C, and 13.3mmol of n-butyl lithium was added to start the reaction for 40min to form -IR- segments. Then, 130g of macromolecular composite brominating agent was added to the polymerization reactor A and the reaction was continued for 60min until no free monomers were present. At the same time, in a 15L stainless steel polymerization reactor B, argon was passed through the system for replacement three times, and 1400g of heptane, 70g of styrene, 160g of 1,3-butadiene, 3.0g of THF, heated to 65 ° C, added 17.1 mmol n-butyl lithium to start the reaction for 57 minutes to form -SBR- segments, and then added 220 g of macromolecular composite brominating agent to polymerization kettle B, reacted for 80 minutes until no free monomers were present, and then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in a 15L stainless steel polymerization kettle C, argon was passed through the system to replace 3 times, and 1500 g of heptane, 140 g of styrene, 1.8 g of THF, heated to 64°C, 9.5 mmol n-butyl lithium was added to start the reaction for 40 minutes, and then 18 g 1,3-butadiene was added for end-capping, and the reaction was carried out for 24 minutes to form -PS-B- segments; until no free monomers were present, and then the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 84°C, 60.7 mmol 1,3,5-trichlorobenzene was added, and the reaction was carried out for 76 minutes, and then the reaction mixture after coupling was treated with water. The glue was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent (Mn was 61000, Mw / Mn was 10.25).

[0093] (2) Preparation of tri-arm brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen was purged four times. 600g of chloromethane, 400g of cyclohexane, and 35.0g of a high-molecular-weight tri-arm brominated grafting agent were added to the reactor and stirred for 95 minutes until completely dissolved. Then, when the temperature was lowered to -85°C, 700g of chloromethane, 441g of isobutylene, and 24g of isoprene were added in sequence and stirred until the polymerization system temperature dropped to -95°C. Then, 120g of chloromethane, 1.85g of sesquiethylaluminum chloride, and 0.067g of HCl were mixed and aged at -89°C for 54 minutes. The mixture was then added to the polymerization system and stirred for 6.0 hours. Finally, 35g of methanol was added, the material was discharged, condensed, washed, and dried to obtain a tri-arm brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared. The test properties are shown in Table 1.

[0094] Example 4

[0095] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0096] a. Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen was replaced three times, and 2600g of heptane, 860g of 1,2-dibromoethylene, 140g of cis-2-methyl-1,4-dibromo-2-butene, and 2.5g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the reactor temperature reached 63°C, 3.0g of DTBP was added and the reaction was carried out for 4.3 hours. Then, 24g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 46 minutes until no free monomer was present. After the reaction was completed, the reaction was washed and dried to obtain a macromolecular composite brominating agent.

[0097] b. Preparation of high molecular weight three-arm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for replacement three times, and 1700g of heptane, 130g of isoprene, and 2.2g of THF were added to the polymerization reactor in sequence. The temperature was raised to 56°C, and 15.1mmol of n-butyl lithium was added to start the reaction for 43min to form -IR- segments. Then, 150g of macromolecular composite brominating agent was added to the polymerization reactor A and the reaction was continued for 65min until no free monomers were present. At the same time, in a 15L stainless steel polymerization reactor B, argon was passed through the system for replacement three times, and 1600g of heptane, 80g of styrene, 150g of 1,3-butadiene, 3.5g of THF, heated to 66 ° C, added 19.2 mmol n-butyl lithium to start the reaction for 60 minutes to form -SBR- segments, and then added 230 g of macromolecular composite brominating agent to polymerization kettle B, and reacted for 83 minutes until no free monomers were present. Then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in 15L stainless steel polymerization kettle C, argon was passed through the system to replace 3 times, and 1700 g of heptane, 160 g of styrene, 2.0 g of THF, heated to 66°C, 10.7 mmol n-butyl lithium was added to start the reaction for 42 minutes, and then 20 g 1,3-butadiene was added for end-capping, and the reaction was carried out for 26 minutes to form -PS-B- segments; until no free monomers were present, and then the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 86°C, 70.7 mmol 1,3,5-trichlorobenzene was added, and the reaction was carried out for 80 minutes, and then the reaction mixture after coupling was treated with water. The glue was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent (Mn was 64000, Mw / Mn was 10.62).

[0098] (2) Preparation of tri-arm brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen was purged four times. 500g of chloromethane, 500g of cyclohexane, and 38.0g of a high molecular weight tri-arm brominated grafting agent were added to the reactor and stirred for 97 minutes until they were completely dissolved. Then, when the temperature was lowered to -87°C, 800g of chloromethane, 436g of isobutylene, and 26g of isoprene were added in sequence and stirred until the polymerization system temperature dropped to -97°C. Then, 130g of chloromethane, 2.12g of sesquiethylaluminum chloride, and 0.086g of HCl were mixed and aged at -91°C for 56 minutes. The mixture was then added to the polymerization system and stirred for 6.3 hours. Finally, 40g of methanol was added, the product was discharged, condensed, washed, and dried to obtain a tri-arm brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared. The test properties are shown in Table 1.

[0099] Example 5

[0100] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0101] Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen was replaced four times, and 2800g of heptane, 880g of 1,2-dibromoethylene, 120g of cis-2-methyl-1,4-dibromo-2-butene, and 3.0g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the reactor temperature reached 67°C, 3.5g of DTBP was added and the reaction was carried out for 4.8 hours. Then, 28g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 48 minutes until no free monomer was present. After the reaction was completed, the reaction was washed and dried to obtain a macromolecular composite brominating agent.

[0102] b. Preparation of high molecular weight three-arm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for 4 times, and 1900g of heptane, 110g of isoprene, and 2.5g of THF were added to the polymerization reactor in sequence. The temperature was raised to 58°C, and 16.7mmol of n-butyl lithium was added to start the reaction for 47min to form -IR- segments. Then, 180g of macromolecular composite brominating agent was added to the polymerization reactor A and the reaction was continued for 70min until no free monomers were present. At the same time, in a 15L stainless steel polymerization reactor B, argon was passed through the system for 3 times, and 1800g of heptane, 90g of styrene, 130g of 1,3-butadiene, 4.0g of THF, heated to 68 ° C, added 20.2 mmol n-butyl lithium to start the reaction for 65 minutes to form -SBR- segments, and then added 240 g of macromolecular composite brominating agent to polymerization kettle B, and reacted for 87 minutes until no free monomers were present. Then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in 15L stainless steel polymerization kettle C, argon was passed through the system to replace 4 times, and 1900 g of heptane, 180 g of styrene, 2.5 g of THF, heated to 68°C, 12.1 mmol n-butyl lithium was added to start the reaction for 47 minutes, and then 25 g 1,3-butadiene was added for end-capping, and the reaction was carried out for 28 minutes to form -PS-B- segments; until no free monomers were present, and then the materials in polymerization kettle C were added to polymerization kettle A; finally, polymerization kettle A was heated to 88°C, 80.1 mmol 1,3,5-trichlorobenzene was added, and the reaction was carried out for 85 minutes, and then the reaction mixture after coupling was treated with water. The glue was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent (Mn was 68000, Mw / Mn was 10.96).

[0103] (2) Preparation of tri-arm brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen was purged five times. 450g of chloromethane, 550g of cyclohexane, and 40.0g of a high-molecular-weight tri-arm brominated grafting agent were added to the reactor and stirred for 98 minutes until they were completely dissolved. Then, when the temperature was lowered to -88°C, 900g of chloromethane, 432g of isobutylene, and 28g of isoprene were added in sequence and stirred until the polymerization system temperature dropped to -99°C. Then, 140g of chloromethane, 2.56g of sesquiethylaluminum chloride, and 0.091g of HCl were mixed and aged at -93°C for 58 minutes. The mixture was then added to the polymerization system and stirred for 6.8 hours. Finally, 45g of methanol was added, the product was discharged, condensed, washed, and dried to obtain a tri-arm brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared. The test properties are shown in Table 1.

[0104] Example 6

[0105] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0106] a. Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen was replaced four times, and 3000g of heptane, 900g of 1,2-dibromoethylene, 100g of cis-2-methyl-1,4-dibromo-2-butene, and 4.0g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 70°C, 4.0g of DTBP was added and the reaction was carried out for 5.0 hours. Then, 30g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 50 minutes until no free monomer was present. After the reaction was completed, the mixture was washed and dried to obtain a macromolecular composite brominating agent.

[0107] b. Preparation of high molecular weight three-arm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for replacement 4 times, and 2000g of heptane, 100g of isoprene, and 3.0g of THF were added to the polymerization reactor in sequence. The temperature was raised to 60°C, and 17.5mmol of n-butyl lithium was added to start the reaction for 50min to form -IR- segments. Then, 200g of macromolecular composite brominating agent was added to the polymerization reactor A and the reaction was continued for 80min until no free monomers were present. At the same time, in a 15L stainless steel polymerization reactor B, argon was passed through the system for replacement 4 times, and 2000g of heptane, 100g of styrene, 100g of 1,3-butadiene, 5.0g of THF, heated to 70 ° C, added 22.5 mmol n-butyl lithium to start the reaction for 70 minutes to form -SBR- segments, and then added 250 g of macromolecular composite brominating agent to polymerization kettle B, and reacted for 90 minutes until no free monomers were present. Then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in 15L stainless steel polymerization kettle C, argon was passed through the system to replace 4 times, and 2000 g of heptane, 200 g of styrene, 3.0 g of THF, heated to 70°C, 14.2 mmol of n-butyl lithium was added to start the reaction for 50 minutes, and then 30 g of 1,3-butadiene was added for end-capping, and the reaction was carried out for 30 minutes to form -PS-B- segments; until no free monomers were present, and then the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 90°C, 90.5 mmol of 1,3,5-trichlorobenzene was added, and the reaction was carried out for 90 minutes, and then the reaction mixture after coupling was treated with water. The glue was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent (Mn was 70,000, Mw / Mn was 11.12).

[0108] (2) Preparation of tri-arm brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen was purged five times. 400g of chloromethane, 600g of cyclohexane, and 45.0g of a high molecular weight tri-arm brominated grafting agent were added to the reactor and stirred for 100min until completely dissolved. Then, when the temperature was lowered to -90°C, 1000g of chloromethane, 425g of isobutylene, and 30g of isoprene were added in sequence and stirred until the polymerization system temperature dropped to -100°C. Then, 150g of chloromethane, 3.12g of sesquiethylaluminum chloride, and 0.095g of HCl were mixed and aged at -95°C for 60min and then added to the polymerization system. After stirring and reacting for 7.0hr, 50g of methanol was added. The product was discharged, condensed, washed, and dried to obtain a tri-arm brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared. The test properties are shown in Table 1.

[0109] Comparative Example 1

[0110] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0111] a. Preparation of a macromolecular composite brominating agent: Other conditions were the same as those in Example 1, except that 1,2-dibromoethylene was not added during the preparation of the macromolecular composite brominating agent. That is, first, in a 15L stainless steel reactor with a jacket, nitrogen was replaced twice, and 2000 g of heptane, 200 g of cis-2-methyl-1,4-dibromo-2-butene, and 1.0 g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the reactor temperature reached 50°C, 1.0 g of DTBP was added and the reaction was carried out for 3.0 hours. Then, 10 g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 40 minutes until no free monomer was present. After the reaction was completed, the mixture was washed and dried to obtain a macromolecular composite brominating agent-1.

[0112] b. Preparation of a high molecular weight three-arm brominated grafting agent: Other conditions were the same as those in Example 1, except that: a macromolecular composite brominating agent was not added during the preparation of the high molecular weight three-arm brominated grafting agent, but a macromolecular composite brominating agent-1 was added, namely: first, in a 15L stainless steel reactor A with a jacket, argon was replaced twice, 1000g of heptane, 200g of isoprene, and 1.0g of THF were added to the polymerization reactor in sequence, the temperature was raised to 50°C, 10.3mmol of n-butyl lithium was added to start the reaction for 30min to form -IR- segments, and then 100g of macromolecular composite brominating agent-1 was added to the polymerization reactor A and the reaction was continued for 50min until no free monomers were present; at the same time, in a 15L stainless steel polymerization reactor B, argon was replaced twice, 1000g of heptane, 50g of styrene, 200g of 1,3-butadiene, 2.0g of THF, heated to 60 ° C, added 15.3 mmol n-butyl lithium to start the reaction for 50 minutes to form -SBR- segments, and then added 200 g of macromolecular composite brominating agent-1 to polymerization kettle B, reacted for 70 minutes until no free monomers were present, and then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in a 15L stainless steel polymerization kettle C, argon was passed through the system to replace it twice, and 1000 g of heptane, 100 g of styrene, and 1.0 g of THF were added in sequence, heated to 60 ° C, 6.3 mmol n-butyl lithium was added to start the reaction for 30 minutes, and then 10 g of 1,3-butadiene was capped and the reaction was continued for 20 minutes to form -PS-B- segments; until no free monomers were present, the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 80°C, 40.7 mmol 1,3,5-trichlorobenzene was added and the reaction was continued for 70 minutes, and then the reaction mixture after coupling was treated with water. The gel was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent-1 (Mn was 45,000, Mw / Mn was 7.12).

[0113] (2) Preparation of tri-arm brominated branched butyl rubber: Other conditions are the same as those in Example 1, except that: in the preparation process of tri-arm brominated branched butyl rubber, instead of adding a high molecular tri-arm brominated grafting agent, a high molecular tri-arm brominated grafting agent-1 is added in an amount of 30 g, that is: first, in a 4L stainless steel reactor with a jacket, nitrogen is replaced three times, 300 g of chloromethane, 200 g of cyclohexane, and 30.0 g of high molecular tri-arm brominated grafting agent-1 are added to the polymerization reactor, and stirred and dissolved for 90 minutes until completely dissolved, and then when the temperature is cooled to 80°C, 500 g of chloromethane, 450 g of isobutylene, and 20 g of isoprene are added in sequence, and stirred and mixed until the polymerization system temperature drops to -90°C, and then 100 g of chloromethane, 1.49 g of sesquiethylaluminum chloride and HCl are added. After mixing and aging at -85°C for 50 minutes, 0.032g of the butyl rubber was added to the polymerization system and stirred for 5.0 hours. Finally, 25g of methanol was added, the product was coagulated, washed, and dried to obtain a three-arm brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test properties are shown in Table 1.

[0114] Comparative Example 2

[0115] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0116] a. Preparation of a macromolecular composite brominating agent: Other conditions were the same as those in Example 2, except that 1,3-butadiene was not added for end-capping in the preparation of the macromolecular composite brominating agent. That is, first, in a 15L stainless steel reactor with a jacket, nitrogen was replaced twice, and 2300g of heptane, 810g of 1,2-dibromoethylene, 190g of cis-2-methyl-1,4-dibromo-2-butene, and 1.5g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the reactor temperature reached 55°C, 1.5g of DTBP was added and the reaction was carried out for 3.5hr; until no free monomer was present. After the reaction was completed, the mixture was washed and dried to obtain a macromolecular composite brominating agent-2.

[0117] b. Preparation of a high molecular weight three-arm brominated grafting agent: Other conditions were the same as those in Example 2, except that: in the preparation of the high molecular weight three-arm brominated grafting agent, no macromolecular composite brominating agent was added, but a macromolecular composite brominating agent-2 was added, namely: first, in a 15L stainless steel reactor A with a jacket, argon was replaced twice, 1200g of heptane, 180g of isoprene, and 1.2g of THF were added to the polymerization reactor in sequence, the temperature was raised to 52°C, 11.3mmol of n-butyl lithium was added to start the reaction for 35min to form -IR- segments, and then 110g of macromolecular composite brominating agent-2 was added to the polymerization reactor A and the reaction was continued for 55min until no free monomers were present; at the same time, in a 15L stainless steel polymerization reactor B, argon was replaced twice, 1100g of heptane, 60g of styrene, 180g of 1,3-butadiene, 2.5g of THF, heated to 62 ° C, added 16.5 mmol n-butyl lithium to start the reaction for 53 minutes to form -SBR- segments, and then added 210 g of macromolecular composite brominating agent-2 to polymerization kettle B, and reacted for 75 minutes until no free monomers were present. Then the materials in polymerization kettle B were added to polymerization kettle A; at the same time, in 15L stainless steel polymerization kettle C, argon was passed through the system to replace it twice, and 1200 g of heptane, 120 g of styrene, 1.3 g of THF, heated to 62°C, 8.3 mmol n-butyl lithium was added to start the reaction for 35 minutes, and then 15 g 1,3-butadiene was added for end-capping, and the reaction was carried out for 22 minutes to form -PS-B- segments; until no free monomers were present, and then the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 82°C, 50.7 mmol 1,3,5-trichlorobenzene was added, and the reaction was carried out for 73 minutes, and then the reaction mixture after coupling was treated with water. The glue was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent-2 (Mn is 41000, Mw / Mn is 6.85).

[0118] (2) Preparation of tri-arm brominated branched butyl rubber: Other conditions are the same as those in Example 2, except that: in the preparation process of tri-arm brominated branched butyl rubber, instead of adding a high molecular tri-arm brominated grafting agent, a high molecular tri-arm brominated grafting agent-2 is added in an amount of 32.0 g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen is replaced three times, 200 g of chloromethane, 300 g of cyclohexane, and 32.0 g of high molecular tri-arm brominated grafting agent-2 are added to the polymerization reactor, and stirred and dissolved for 92 minutes until completely dissolved. Then, when the temperature is cooled to -80°C, 600 g of chloromethane, 446 g of isobutylene, and 22 g of isoprene are added in sequence, and stirred and mixed until the temperature of the polymerization system drops to -92°C. Then, 110 g of chloromethane, 1.67 g of sesquiethylaluminum chloride and HCl are added. After mixing and aging 0.051 g of the butyl rubber at -87°C for 52 minutes, the mixture was added to the polymerization system and stirred for 5.5 hours. Finally, 30 g of methanol was added, the product was coagulated, washed, and dried to obtain a three-arm brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test properties are shown in Table 1.

[0119] Comparative Example 3

[0120] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0121] a. Preparation of macromolecular composite brominating agent: same as Example 3.

[0122] b. Preparation of a high molecular weight three-arm brominated grafting agent: Other conditions were the same as those in Example 3, except that: in the preparation process of the high molecular weight three-arm brominated grafting agent, no macromolecular composite brominating agent was added, but 1,2-dibromoethylene was added, namely: first, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for replacement three times, and 1500g of heptane, 160g of isoprene, and 1.8g of THF were added to the polymerization reactor in sequence, and the temperature was raised to 54°C, 13.3mmol of n-butyl lithium was added to start the reaction for 40min to form -IR- segments, and then 130g of 1,2-dibromoethylene was added to the polymerization reactor A and the reaction was continued for 60min until no free monomers were present; at the same time, in a 15L stainless steel polymerization reactor B, argon was passed through the system for replacement three times, and 1400g of heptane, 70g of styrene, 160g of 1,3-butadiene, 3.0g of THF, heated to 65 ° C, added 17.1 mmol n-butyl lithium to start the reaction for 57 minutes to form -SBR- segments, and then added 220 g of 1,2-dibromoethylene to the polymerization kettle B and reacted for 80 minutes until no free monomers were present. Then the materials in the polymerization kettle B were added to the polymerization kettle A; at the same time, in the 15L stainless steel polymerization kettle C, the system was replaced 3 times with argon, and 1500 g of heptane, 140 g of styrene, 1.8 g of THF, heated to 64°C, 9.5 mmol n-butyl lithium was added to start the reaction for 40 minutes, and then 18 g 1,3-butadiene was added for end-capping, and the reaction was carried out for 24 minutes to form -PS-B- segments; until no free monomers were present, and then the materials in polymerization reactor C were added to polymerization reactor A; finally, polymerization reactor A was heated to 84°C, 60.7 mmol 1,3,5-trichlorobenzene was added, and the reaction was carried out for 76 minutes, and then the reaction mixture after coupling was treated with water. The glue was wet-coagulated and dried to obtain a high molecular weight three-arm brominated grafting agent-3 (Mn is 49000, Mw / Mn is 6.52).

[0123] (2) Preparation of tri-arm brominated branched butyl rubber: Other conditions are the same as those in Example 3, except that: in the preparation process of tri-arm brominated branched butyl rubber, instead of adding a high molecular tri-arm brominated grafting agent, a high molecular tri-arm brominated grafting agent-3 is added in an amount of 35.0 g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen is replaced 4 times, 600 g of chloromethane, 400 g of cyclohexane, and 35.0 g of high molecular tri-arm brominated grafting agent-3 are added to the polymerization reactor, and the mixture is stirred and dissolved for 95 minutes until it is completely dissolved. Then, when the temperature is lowered to -85°C, 700 g of chloromethane, 441 g of isobutylene, and 24 g of isoprene are added in sequence, and the mixture is stirred and mixed until the temperature of the polymerization system drops to -95°C. Then, 120 g of chloromethane, 1.85 g of sesquiethylaluminum chloride and HCl are added. After mixing and aging 0.067 g of the butyl rubber at -89°C for 54 minutes, the mixture was added to the polymerization system and stirred for 6 hours. Finally, 35 g of methanol was added, the product was coagulated, washed, and dried to obtain a three-arm brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test properties are shown in Table 1.

[0124] Comparative Example 4

[0125] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0126] a. Preparation of macromolecular composite brominating agent: same as Example 4.

[0127] b. Preparation of high molecular weight three-arm brominated grafting agent: same as Example 4.

[0128] (2) Preparation of tri-arm brominated branched butyl rubber: Other conditions were the same as those in Example 4, except that: in the preparation process of tri-arm brominated branched butyl rubber, the amount of high molecular tri-arm brominated grafting agent added was 10 g, that is: first, in a 4L stainless steel reactor with a jacket, nitrogen was purged 4 times, 500 g of chloromethane, 500 g of cyclohexane, and 10.0 g of high molecular tri-arm brominated grafting agent were added to the polymerization reactor, and stirred and dissolved for 97 minutes until completely dissolved, and then when the temperature was cooled to -87°C, 800 g of chloromethane, 436 g of isobutylene, and 26 g of isoprene were added in sequence, and stirred and mixed until the polymerization system temperature dropped to -97°C, and then 130 g of chloromethane, 2.12 g of sesquiethylaluminum chloride and HCl were added. After mixing and aging 0.086g of the butyl rubber at -91°C for 56 minutes, the mixture was added to the polymerization system and stirred for 6.3 hours. Finally, 40g of methanol was added, the product was coagulated, washed, and dried to obtain a three-arm brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test properties are shown in Table 1.

[0129] Comparative Example 5

[0130] (1) Preparation of high molecular weight three-arm brominated grafting agent:

[0131] a. Preparation of macromolecular composite brominating agent: same as Example 5.

[0132] b. Preparation of a high molecular weight three-arm brominated grafting agent: Other conditions were the same as those in Example 4, except that: during the preparation of the high molecular weight three-arm brominated grafting agent, the material of the -PS-B- segment in the polymerization kettle C was not added to the polymerization kettle A, that is: first, in a 15L stainless steel reactor A with a jacket, argon was passed through the system for 4 times, and 1900g of heptane, 110g of isoprene, and 2.5g of THF were added to the polymerization kettle in sequence, and the temperature was raised to 58°C. 16.7mmol of n-butyl lithium was added to start the reaction for 47min to form the -IR- segment, and then 180g of a macromolecular composite brominating agent was added to the polymerization kettle A and the reaction was continued for 70min until no free monomer was present; at the same time, in a 15L stainless steel polymerization kettle B, argon was passed through the system for 3 times, and 1800g of heptane, 90g of styrene, 130g of 1,3-butadiene, 4.0g of THF, heated to 68 ° C, added 20.2 mmol n-butyl lithium to start the reaction for 65 minutes to form -SBR- segments, and then added 240 g of a macromolecular composite brominating agent to the polymerization kettle B, reacted for 87 minutes until no free monomers existed, and then the materials in the polymerization kettle B were added to the polymerization kettle A; finally, the polymerization kettle A was heated to 88 ° C, 80.1 mmol 1,3,5-trichlorobenzene was added, and the reaction was carried out for 85 minutes. The reaction mixture after coupling was then treated with water, and the glue was wet-coagulated and dried to obtain a high molecular weight two-arm brominated grafting agent (Mn was 59000, Mw / Mn was 5.16).

[0133] (2) Preparation of tri-arm brominated branched butyl rubber: Other conditions are the same as those in Example 5, except that: in the preparation process of tri-arm brominated branched butyl rubber, a high molecular tri-arm brominated grafting agent is not added, but a high molecular di-arm brominated grafting agent is added in an amount of 40.0 g, that is: first, in a 4L stainless steel reactor with a jacket, nitrogen is replaced 5 times, 450 g of chloromethane, 550 g of cyclohexane, and 40.0 g of the high molecular di-arm brominated grafting agent are added to the polymerization reactor, and stirred and dissolved for 98 minutes until completely dissolved. Then, when the temperature is cooled to -88°C, 900 g of chloromethane, 432 g of isobutylene, and 28 g of isoprene are added in sequence, and stirred and mixed until the temperature of the polymerization system drops to -99°C. Then, 140 g of chloromethane, 2.56 g of sesquiethylaluminum chloride and HCl are added. After mixing and aging 0.091 g of the butyl rubber at -93°C for 58 minutes, the mixture was added to the polymerization system and stirred for 6.8 hours. Finally, 45 g of methanol was added, the product was coagulated, washed, and dried to obtain a three-arm brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test properties are shown in Table 1.

[0134] Comparative Example 6

[0135] (1) Preparation of high molecular weight brominated grafting agent:

[0136] a. Preparation of macromolecular composite brominating agent: same as Example 6.

[0137] b. Preparation of a high molecular weight brominated grafting agent: Other conditions were the same as those in Example 6, except that 1,3,5-trichlorobenzene was not added for coupling during the preparation of the high molecular weight brominated grafting agent. Specifically, argon was passed through a jacketed 15 L stainless steel reactor A for four replacements, and 2000 g of heptane, 100 g of isoprene, and 3.0 g of THF were added to the reactor in sequence. The temperature was raised to 60° C., and 17.5 mmol of n-butyl lithium was added to initiate the reaction for 50 min to form -IR- segments. 200 g of a high molecular weight composite brominating agent was then added to the reactor A and the reaction was continued for 80 min until no free monomers were present. Simultaneously, argon was passed through a 15 L stainless steel reactor B for four replacements, and 2000 g of heptane, 100 g of styrene, 100 g of 1,3-butadiene, 5.0gTHF, heated to 70℃, added 22.5mmol n-butyl lithium to start the reaction for 70min to form -SBR- segment, then added 250g macromolecular composite brominating agent to polymerization kettle B, reacted for 90min until no free monomer existed, then added the materials in polymerization kettle B to polymerization kettle A; at the same time, in 15L stainless steel polymerization kettle C, argon was passed through the system to replace 4 times, and 2000g heptane, 200g styrene, 3.0g THF, heated to 70°C, 14.2 mmol of n-butyl lithium was added to start the reaction for 50 minutes, and then 30 g of 1,3-butadiene was added for end-capping, and the reaction was continued for 30 minutes to form -PS-B- segments; until no free monomers were present, the material in polymerization reactor C was added to polymerization reactor A; finally, wet coagulation and drying were performed to obtain a high molecular linear brominated grafting agent (Mn was 630,000, Mw / Mn was 3.55).

[0138] (2) Preparation of brominated branched butyl rubber: Other conditions were the same as those in Example 6, except that: in the preparation of brominated branched butyl rubber, instead of adding a high molecular weight three-arm brominated grafting agent, a high molecular weight linear brominated grafting agent was added in an amount of 45.0 g. That is, first, in a 4 L stainless steel reactor with a jacket, nitrogen was replaced 5 times, 400 g of monochloromethane, 600 g of cyclohexane, and 45.0 g of the high molecular weight linear brominated grafting agent were added to the polymerization reactor, and the mixture was stirred and dissolved for 100 min until it was completely dissolved. The mixture was then cooled to -90°C, followed by the addition of 1000g of methyl chloride, 425g of isobutylene, and 30g of isoprene. The mixture was stirred until the polymerization temperature dropped to -100°C. Then, 150g of methyl chloride, 3.12g of sesquiethylaluminum chloride, and 0.095g of HCl were mixed and aged at -95°C for 60 minutes before being added to the polymerization system. The mixture was stirred and reacted for 7 hours. Finally, 50g of methanol was added, the product was discharged, coagulated, washed, and dried to obtain a brominated branched butyl rubber product. Sampling and Analysis: Standard specimens were prepared. The test properties are shown in Table 1.

[0139] Table 1 Properties of tri-arm brominated branched butyl rubber

[0140]

[0141]

[0142] Note: 10 The scorch time reflects the size of the scorch safety window; t 90 The positive vulcanization time reflects the speed of vulcanization.

[0143] As shown in Table 1, the brominated branched butyl rubber of the present invention has a wide molecular weight distribution, a high vulcanization rate and a low Mooney stress relaxation time, exhibiting good processing and vulcanization characteristics while maintaining high tensile strength and good air tightness.

[0144] The above embodiments are typical examples listed to illustrate the technical solutions of the present invention in detail. The present invention is subject to the scope of protection of the claims and the content of the invention and is not limited to the embodiments. Simple replacement or modification of the present invention is still within the scope of protection of the present invention.

Claims

1. A method for preparing a three-arm brominated branched butyl rubber, comprising the following steps: S1: adding a high molecular weight three-arm brominated grafting agent to a mixed solvent, and stirring thoroughly until the high molecular weight three-arm brominated grafting agent is completely dissolved to obtain a mixed solution; S2: Cooling the mixture, sequentially adding a diluent, isobutylene, and isoprene to the mixed solution of step S1, stirring and mixing the mixture to obtain a polymerization reaction system, and cooling the mixture again; S3: mixing the diluent and the co-initiator and aging them, then adding them to the polymerization reaction system of step S2, stirring them thoroughly for reaction, adding a terminator, coagulating the discharged material, washing, and drying it to obtain a three-arm brominated branched butyl rubber; It is characterized in that the preparation method of the polymer three-arm brominated grafting agent specifically comprises the following steps: a. Preparation of a macromolecular composite brominating agent: first, based on 100 parts by mass of the reactive brominating agent, add 200-300 parts of solvent, 80-90 parts of 1,2-dibromoethylene, 10-20 parts of cis-2-methyl-1,4-dibromo-2-butene, and 0.1-0.4 parts of a molecular weight regulator to a reactor after inert gas replacement, stir and mix, and heat. When the temperature of the reactor reaches 50-70° C., add 0.1-0.5 parts of a first initiator and react for 3.0-5.0 hours, at which time the conversion of 1,2-dibromoethylene reaches 100%; then, add 1-3 parts of 1,3-butadiene to the reactor for end-capping, and react for 40-50 minutes until no free monomer is present. After the reaction is completed, wash and dry to obtain a macromolecular composite brominating agent; b. Preparation of a high molecular weight three-arm brominated grafting agent: first, based on 100% of the total weight of the reaction monomers, add 100wt% to 200wt% of solvent, 10wt% to 20wt% of isoprene, 0.1wt% to 0.3wt% of a structure regulator, and a second initiator to a reactor A after inert gas replacement, raise the temperature to 50 to 60°C, react for 30 to 50 minutes to form an -IR- segment, then add 10wt% to 20wt% of a macromolecular composite brominating agent to the reactor A, react for 50 to 80 minutes until no free monomers are present; simultaneously, add 100wt% to 200wt% of solvent, 5wt% to 10wt% of styrene, 10wt% to 20wt% of 1,3-butadiene, 0.2wt% to 0.5wt% of a structure regulator, and a second initiator to a reactor B after inert gas replacement, raise the temperature to 60 to 70°C, react for 50 to 70 minutes to form an -SBR- segment, and then Then, 20 wt% to 25 wt% of a macromolecular composite brominating agent is added to reactor B, and the reaction is carried out for 70 to 90 minutes until no free monomers are present. Then, the materials in reactor B are added to reactor A. Simultaneously, 100 wt% to 200 wt% of a solvent, 10 wt% to 20 wt% of styrene, 0.1 wt% to 0.3 wt% of a structure regulator, and a second initiator are added to reactor C after inert gas replacement. The temperature is raised to 60 to 70° C., and the reaction is carried out for 30 to 50 minutes. Then, 1 to 3 wt% of 1,3-butadiene is added for end-capping, and the reaction is carried out for 20 to 30 minutes to form -PS-B- segments, until no free monomers are present. Then, the materials in reactor C are added to reactor A. Finally, the temperature of reactor A is raised to 80 to 90° C., a coupling agent is added for coupling reaction, and the reaction mixture after reaction is treated with water. The reaction mixture is subjected to wet coagulation and drying to obtain a high molecular weight three-arm bromination grafting agent. The number average molecular weight (Mn) of the high molecular weight three-arm brominated grafting agent is 50,000-70,000, and the molecular weight distribution (Mw / Mn) is 9.27-11.

14.

2. The preparation method of the three-arm brominated branched butyl rubber according to claim 1, wherein In step S1, the mass ratio of the mixed solvent to the high molecular weight three-arm brominated grafting agent is 100-200:6-9; the mixed solvent includes a diluent and a solvent, and the volume ratio of the diluent to the solvent is 60-40 / 40-60.

3. The preparation method of the three-arm brominated branched butyl rubber according to claim 2, wherein The solvent is selected from at least one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene.

4. The preparation method of the three-arm brominated branched butyl rubber according to claim 2, wherein The solvent is heptane.

5. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein In step S2, the temperature is lowered to -80 to -90°C, and the temperature is lowered again to -100 to -90°C.

6. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein In step S2, the mass ratio of the diluent, isobutylene and isoprene is 100-200:85-90:4-6.

7. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein In step S3, the mass ratio of the diluent, the co-initiator and the terminator is 20-30:0.3-0.7:5-10.

8. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein The molecular weight regulator is selected from at least one of tert-decyl mercaptan, tert-dodecyl mercaptan, tert-tetradecyl mercaptan, and tert-hexadecanethiol; The first initiator is an organic peroxide, selected from at least one of 1,1-dimethylethyl peroxide, 1,1-dimethylethyl-1-methyl-1-[3-(1-methylvinyl)phenyl]ethyl peroxide, tert-butyl peroxide, di-tert-butyl peroxide (DTBP) and tert-pentyl oxide (DTAP); The structure regulator is a polar organic compound selected from the group consisting of diethylene glycol dimethyl ether (DGE), tetrahydrofuran (THF), ethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME), and triethylamine; The second initiator is a hydrocarbon monolithium compound RLi, which is at least one selected from n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium, and dodecyllithium.

9. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein The molecular weight regulator is tert-dodecyl mercaptan.

10. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The first initiator is di-tert-butyl peroxide (DTBP).

11. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The structure regulator is tetrahydrofuran (THF).

12. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The second initiator is n-butyl lithium.

13. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The coupling agent is at least one of 1,3,5-trichlorobenzene and 1,3,5-tribromobenzene; and the molar ratio of the coupling agent to the second initiator is 1:1 to 5:

1.

14. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The coupling agent is 1,3,5-trichlorobenzene.

15. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: In the preparation method of the polymer tri-arm brominated grafting agent, the solvents in step a and step b are independently selected from at least one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene.

16. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: In the preparation method of the polymer tri-arm brominated grafting agent, the solvent in step a and step b is heptane.

17. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The diluent is a halogenated alkane, selected from at least one of monochloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, monofluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane.

18. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The diluent is methyl chloride.

19. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The co-initiator is composed of an alkyl aluminum halide and a protonic acid mixed in proportion; the alkyl aluminum halide is selected from at least one of diethylaluminum monochloride, diisobutylaluminum monochloride, methylaluminum dichloride, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, n-propylaluminum dichloride, isopropylaluminum dichloride, dimethylaluminum chloride and ethylaluminum chloride; the protonic acid is selected from at least one of HCl, HF, HBr, H2SO4, H2CO3, H3PO4 and HNO3; and the molar ratio of the protonic acid to the alkyl aluminum halide is 0.05:1 to 0.5:

1.

20. The method for preparing the three-arm brominated branched butyl rubber according to claim 19, wherein: The alkylaluminum halide is ethylaluminum sesquichloride.

21. The method for preparing the three-arm brominated branched butyl rubber according to claim 19, wherein: The protonic acid is HCl.

22. The method for preparing the three-arm brominated branched butyl rubber according to claim 1, wherein: The terminator is at least one of methanol, ethanol and butanol.

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