A method for preparing a three-hetero-arm per-secondary position brominated branched butyl rubber

Abstract

The application discloses a preparation method of three-hetero-arm full-sec-position brominated branched butyl rubber, which comprises the following steps: adding a high-molecular three-hetero-arm brominated grafting agent into a mixed solvent, fully stirring until the high-molecular three-hetero-arm brominated grafting agent is dissolved, and obtaining a mixed solution; cooling, adding a diluent, isobutene and isoprene into the mixed solution in sequence, fully stirring and mixing, obtaining a polymerization reaction system, and cooling again; mixing and aging the diluent and a co-initiator, then adding the diluent and the co-initiator into the polymerization reaction system, fully stirring and reacting, adding a terminating agent, discharging, coagulating, washing, drying, and obtaining the three-hetero-arm full-sec-position brominated branched butyl rubber; the high-molecular three-hetero-arm brominated grafting agent is a three-hetero-arm full-sec-position brominated star block copolymer which is composed of isoprene, 1,3-butadiene, styrene and a macromolecular complex brominated agent. The preparation method of the application enables the butyl rubber to maintain sufficient raw rubber strength and good air tightness, and to give a balance of physical mechanical properties and vulcanization processing properties.

Description

Technical Field

[0001] This invention relates to a method for preparing a tri-hetero-arm fully secondary brominated branched butyl rubber, specifically a method for preparing a high-molecular-weight-distribution brominated branched butyl rubber by graft modification of a fully secondary brominated isoprene / butadiene / styrene tri-hetero-arm star-shaped block copolymer. Background Technology

[0002] Butyl rubber (IIR) is a cationic copolymer of isobutylene and a small amount of isoprene. It possesses excellent airtightness, 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, thus becoming one of the most important synthetic rubber varieties. However, butyl rubber molecules are mainly composed of carbon-carbon single bonds with low unsaturation. The symmetrical arrangement of substituent methyl groups results in high crystallinity, poor molecular chain flexibility, slow stress release rate, slow vulcanization speed, poor adhesion, and poor compatibility with other general-purpose rubbers. These drawbacks make butyl rubber prone to excessive flow and deformation during processing, thus becoming a bottleneck for expanding the applications of butyl rubber materials.

[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 influence of molecular bromine. Compared to IIR, BIIR, in addition to possessing the same excellent airtightness, not only increases the polarity of the molecular chain due to the introduction of bromine atoms, improving adhesion to other rubbers and allowing it to be used in any ratio with unsaturated rubbers such as natural rubber and styrene-butadiene rubber, but also generates additional crosslinking sites, enhancing the activity of the original double bonds, improving the vulcanization performance of the rubber compound, resulting in faster vulcanization and more diverse vulcanization methods; heat resistance is also improved. Therefore, BIIR is gradually replacing IIR in industrial products such as radial tires, tubeless tires, medical sealing devices, and chemical equipment linings, demonstrating broad industrial application value and prospects.

[0004] In recent years, researchers have discovered a star-branched butyl rubber composed of a high-molecular-weight branched structure and a low-molecular-weight linear structure. This star-branched butyl rubber can be brominated to obtain brominated star-branched butyl rubber. This brominated star-branched butyl rubber, due to its unique "three-dimensional network" branched structure and bromine atoms, possesses both a wide molecular weight distribution and excellent viscoelastic properties, as well as high raw rubber strength and fast vulcanization speed. In particular, it exhibits low melt viscosity, low processing energy consumption, low discharge temperature, low shrinkage, and long scorch time during processing, achieving a balanced unity of physical and mechanical properties and processing performance. Therefore, brominated star-branched butyl rubber has become one of the hot topics in future butyl rubber research.

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

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

[0007] CN 101353403B discloses a method for preparing star-branched polyisobutylene or butyl rubber. This method uses a polystyrene / isoprene block copolymer with terminal silanol groups or a polystyrene / butadiene block copolymer with terminal silanol groups as an initiator and grafting agent for cationic polymerization. The method involves direct participation in cationic polymerization in a mixed solvent of chloromethane / cyclohexane with a v:v ratio of 20–80 / 80–20 under temperature conditions of 0–100°C. The cationic polymerization is initiated by silanol groups, and the star-branched polyisobutylene or butyl rubber product is prepared through grafting reactions involving unsaturated chains.

[0008] CN 106749816A discloses a method for preparing brominated butyl rubber. The method first dissolves butyl rubber in n-alkane, then uses specific organic bromides such as phenyltrimethyltribromoamine, benzyltrimethyltribromoamine, or dibromoisocyanuric acid as brominating agents, and Br2 or HBr as bromination accelerators to carry out the bromination reaction in the solvent, thereby obtaining brominated butyl rubber. This method inhibits the molecular rearrangement of secondary bromine in brominated butyl rubber to form berberine bromine, thus 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 for preparing a star-shaped branched butyl rubber with obvious bimodal structure by using poly(isoprene-styrene) block copolymer as a grafting agent through living anionic polymerization in an initiation system of 2-chloro-2,4,4-trimethylpentane / titanium tetrachloride / proton scavenger via cationic polymerization with activated carbon.

[0010] Synthetic Rubber Industry (2006, 29(4): A method for preparing brominated butyl rubber by dissolving butyl rubber (Polysar-301) in cycloalkanes and then brominating it with liquid bromine was disclosed. The effects of residence time and reaction temperature on the Mooney viscosity, degree of unsaturation, bromine content, and microstructure of the product were investigated. The results showed that the Mooney viscosity and degree of unsaturation decreased sharply when the residence time was less than 2 min, and the changes were not significant after 2 min. Increasing the reaction temperature decreased the Mooney viscosity, but had little effect on the degree of unsaturation. Increasing the reaction temperature and extending the residence time not only benefited the increase of bromine content in the product, but also facilitated the rearrangement of its molecular structure, i.e., a transfer from the secondary allyl bromide configuration to the more stable primary allyl bromide configuration.

[0011] In the aforementioned prior art, star-branched butyl rubber or butyl rubber dissolved and brominated to obtain brominated butyl rubber exhibits a larger molecular weight distribution, increased stress relaxation rate, and faster vulcanization speed, demonstrating good processability. However, these methods still have certain limitations. During the bromination process of butyl rubber, hydrogen bromide, a byproduct, is easily generated, leading to the loss of remaining bromine and reducing the utilization rate of bromine. This results in a significant isomerization of the Type III secondary structure in the brominated butyl rubber towards the Type III primary structure, thus affecting the processing performance of the brominated butyl rubber. Furthermore, hydrogen bromide is highly corrosive, leading to a deterioration in the quality of the brominated butyl rubber and potentially causing environmental pollution and human health and safety issues. Summary of the Invention

[0012] The purpose of this invention is to provide a method for preparing a tri-heteroarm, fully secondary brominated branched butyl rubber. This method uses a macromolecular composite brominating agent as a raw material, which is also reactive. Next, isoprene, styrene, butadiene, the macromolecular composite brominating agent, and a coupling agent are reacted via a three-stage reaction with variable-speed reaction to prepare a polymeric tri-heteroarm brominated grafting agent with a broad distribution, fully secondary bromine structure, and a tri-heteroarm structure. Finally, using the polymeric tri-heteroarm brominated grafting agent, isobutylene, and isoprene as reacting monomers, cationic polymerization is used to prepare the tri-heteroarm, fully secondary brominated branched butyl rubber. This method prepares a butyl rubber with a fully secondary bromine structure through addition polymerization, avoiding bromine structure rearrangement, solving the problem of bromine structure stability in brominated branched butyl rubber, and greatly improving scorch safety and vulcanization efficiency during the vulcanization process. At the same time, a wide molecular weight distribution of butyl rubber was achieved, which not only solved the problem of slow stress relaxation rate of butyl rubber during processing, but also maintained 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, "%" in this invention refers to mass percentage.

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

[0015] S1: Add the polymeric tri-arm brominated grafting agent to the mixed solvent and stir thoroughly until the polymeric tri-arm brominated grafting agent is completely dissolved to obtain a mixed solution;

[0016] S2: Cool down, add diluent, isobutylene and isoprene to the mixed solution in step S1 in sequence, stir and mix thoroughly to obtain the polymerization reaction system, and cool down again;

[0017] S3: Mix the diluent and co-initiator and age them. Then add them to the polymerization reaction system of step S2 and stir the reaction thoroughly. Add the terminator, discharge the material, coagulate, wash and dry to obtain the three hetero-arm fully secondary brominated branched butyl rubber.

[0018] The feature is that the polymeric tri-heteroarm brominated grafting agent is a tri-heteroarm fully secondary brominated star-shaped block copolymer composed of isoprene, 1,3-butadiene, styrene, and a macromolecular composite brominated agent, and its general structural formula is shown in Formula I:

[0019]

[0020] Wherein: IR is the isoprene homopolymer block; SB is the random block of styrene and butadiene; (S→B) is the graded block of styrene and butadiene; BR is the 1,3-butadiene homopolymer block; 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 polymeric tri-heteroarm brominated grafting agent is 50,000 to 70,000, and the molecular weight distribution (Mw / Mn) is 11.53 to 13.12.

[0021] In the preparation method of the tri-heteroarm fully secondary brominated branched butyl rubber of the present invention, in step S1, the mass ratio of the mixed solvent and the polymeric tri-heteroarm brominated grafting agent is 100-200:5-10.

[0022] In the preparation method of the tri-arm fully secondary 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 and the solvent is 70-30 / 30-70.

[0023] In the preparation method of the tri-arm fully secondary brominated branched butyl rubber of the present invention, in step S2, the temperature is cooled to -85 to -95°C.

[0024] In the preparation method of the tri-arm fully secondary brominated branched butyl rubber of the present invention, in step S2, the mass ratio of the diluent, isobutylene and isoprene is 100-200:80-90:5-10.

[0025] In the preparation method of the tri-arm fully secondary brominated branched butyl rubber of the present invention, in step S2, the temperature is lowered again to -100 to -95°C.

[0026] In the preparation method of the tri-arm fully secondary brominated branched butyl rubber of the present invention, in step S3, the mass ratio of the diluent, co-initiator and terminator is 10-20:0.2-0.6:3-7.

[0027] In the preparation method of the tri-arm fully secondary brominated branched butyl rubber of the present invention, in step S3, the aging temperature is -95℃ to -85℃ and the aging time is 60 to 70 minutes.

[0028] The preparation method of the tri-heteroarm fully secondary brominated branched butyl rubber of the present invention specifically includes the following steps:

[0029] Preparation of a macromolecular composite brominating agent: Taking 100 parts by mass of reactive brominating agent, firstly, add 200-300 parts of solvent, 70-80 parts of bromovinylbenzene, 20-30 parts of 1,2-dibromoethylene, and 0.2-0.5 parts of molecular weight regulator sequentially to a reaction vessel after inert gas replacement. Stir and mix, heat, and when the reaction vessel temperature reaches 70-80℃, add 0.3-0.7 parts of the first initiator. React for 4.0-6.0 hours, at which point the conversion rate of bromovinylbenzene reaches 100%. Then, add 1-5 parts of 1,3-butadiene to the reaction vessel for end-capping, and react for 50-60 minutes until no free monomers are present. After the reaction is completed, wash and dry to obtain the macromolecular composite brominating agent.

[0030] Preparation of b. Polymer Tri-Hybridized Grafting Agent: Based on 100% of the total mass of the reactants, first, add 100wt%–200wt% solvent, 20wt%–30wt% isoprene, 0.2wt%–0.5wt% structure modifier, and a second initiator sequentially to reactor A after inert gas purging. Heat to 60–70℃ and react for 40–60 min to form -IR- segments. Then, add 20wt%–30wt% macromolecular composite... The brominating agent is added, and the reaction proceeds for 70–90 minutes until no free monomers remain. Simultaneously, 100 wt%–200 wt% solvent, 0.3 wt%–0.6 wt% structure modifier, and a second initiator are added sequentially to reactor B, which has been purged with inert gas. The temperature is raised to 70–80 °C, and 15 wt%–20 wt% styrene and 20 wt%–30 wt% 1,3-butadiene are stirred and mixed for 20–30 minutes. The reaction is a variable-rate polymerization, with the monomers added continuously. In the reactor, the reaction is carried out within 60-80 minutes, with an initial feed rate >7.0% mixture / min. The rate of decrease in feed rate depends on the reaction time, forming random, long, gradient segments -SB / (S→B)-. Then, the material in reactor B is added to reactor A. Simultaneously, in a 15L stainless steel reactor C, the system is purged with argon gas 2-4 times, and 100wt%-200wt% solvent and 10wt%-20wt% 1,3-butadiene are added sequentially. Add 0.1wt% to 0.3wt% of a structure regulator and a second initiator, heat to 40 to 50°C, react for 40 to 60 minutes to form -BR- segments until no free monomers are present. Then add the material from reactor C to reactor A. Finally, heat reactor A to 80 to 90°C, add a coupling agent to carry out a coupling reaction, react for 80 to 100 minutes, and then treat the coupled reaction mixture with water. The gel is then wet-coagulated and dried to obtain a polymeric three-heteroarm brominated grafting agent.

[0031] The method for preparing the tri-arm fully secondary brominated branched butyl rubber of the present invention, wherein the molecular weight regulator may be selected from at least one of tert-decanethiol, tert-dodecanethiol, tert-tetradecanethiol, and tert-hexadecanethiol, preferably tert-dodecanethiol.

[0032] The method for preparing the tri-arm fully secondary brominated branched butyl rubber of the present invention, wherein the first initiator is an organic peroxide selected from at least one of dicumyl peroxide (DCP), cumyl hydroperoxide, benzoyl peroxide (BPO) and di-tert-butyl peroxide, preferably dicumyl peroxide (DCP).

[0033] The method for preparing the tri-arm fully secondary brominated branched butyl rubber of the present invention uses a structure modifier that is a polar organic compound. This compound produces a solvation effect in the polymerization system, enabling the regulation of the reactivity ratio between styrene and isoprene, thus allowing them to copolymerize randomly. This type of polar organic compound is selected from at least one of diethylene glycol dimethyl ether (DGE), tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, diethylene glycol dimethyl ether (DME), and triethylamine, preferably diethylene glycol dimethyl ether (DME).

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

[0035] The method for preparing the tri-arm fully secondary brominated branched butyl rubber of the present invention includes a coupling agent that is at least one selected from 1,3,5-trichlorobenzene and 1,3,5-tribromobenzene, preferably 1,3,5-trichlorobenzene. The amount of 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] In the preparation method of the tri-arm fully secondary brominated branched butyl rubber of the present invention, the polymerization reaction is carried out in an oxygen-free and anhydrous environment, preferably in an inert gas environment. Both the polymerization reaction and the dissolution process are completed in a hydrocarbon solvent. The solvent described in the present invention is a hydrocarbon solvent, which includes straight-chain alkanes, aromatics, and cycloalkanes. This hydrocarbon solvent is selected from at least one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene, and ethylbenzene, preferably octane.

[0037] The method for preparing the tri-arm fully secondary brominated branched butyl rubber of the present invention includes a diluent that is a haloalkane, wherein the halogen atom in the haloalkane can be chlorine, bromine, or fluorine; and the number of carbon atoms in the haloalkane is C1-C4. This haloalkane is selected from at least one of chloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, fluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane, preferably dichloromethane.

[0038] The present invention discloses a method for preparing a tri-arm fully secondary brominated branched butyl rubber, wherein the co-initiator is composed of an alkyl aluminum halide and a protic acid in different proportions. The alkyl aluminum halide is selected from at least one of diethylaluminum chloride, diisobutylaluminum chloride, dichloromethylaluminum, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, dichloro-n-propylaluminum, dichloroisopropylaluminum, dimethylaluminum chloride, and ethylaluminum chloride, preferably sesquiethylaluminum chloride. The protic acid is selected from one of HCl, HF, HBr, H2SO4, H2CO3, H3PO4, and HNO3, preferably HCl. The molar ratio of the protic acid to the alkyl aluminum halide is 0.05:1 to 0.5:1.

[0039] The method for preparing the tri-arm fully secondary brominated branched butyl rubber of the present invention may, for example, but not limited to, at least one of methanol, ethanol, and butanol.

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

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

[0042] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0043] Preparation of a macromolecular composite brominating agent: Taking 100 parts by mass of reactive brominating agent, firstly, in a 15L stainless steel reactor with a jacket, purge with inert gas 2-4 times. Then, add 200-300 parts of solvent, 70-80 parts of bromovinylbenzene, 20-30 parts of 1,2-dibromoethylene, and 0.2-0.5 parts of molecular weight regulator to the reactor in sequence. Stir and mix, heat, and when the reactor temperature reaches 70-80℃, add 0.3-0.7 parts of the first initiator. React for 4.0-6.0 hours, at which point the conversion rate of bromoethylene monomer reaches 100%. Then, add 1-5 parts of 1,3-butadiene to the reactor for end-capping, and react for 50-60 minutes until no free monomers are present. After the reaction is completed, wash and dry to obtain the macromolecular composite brominating agent.

[0044] Preparation of b. Polymer Tri-Hybridized Grafting Agent: Based on 100% of the total mass of the reactants, first, in a jacketed 15L stainless steel reactor A, purge with argon gas 2-4 times. Then, sequentially add 100wt%-200wt% solvent, 20wt%-30wt% isoprene, 0.2wt%-0.5wt% structure modifier, and a second initiator to reactor A. Heat to 60-70℃ and react for 40-60 min to form -IR- segments. Then, add 20... Add 1%–30% macromolecular complex brominating agent and react for 70–90 minutes until no free monomers remain. Simultaneously, in a 15L stainless steel reactor B, purge the system with argon gas 2–4 times, then add 100 wt%–200 wt% solvent, 0.3 wt%–0.6 wt% structure modifier, and a second initiator sequentially. Heat to 70–80°C, and mix 15 wt%–20 wt% styrene and 20 wt%–30 wt% 1,3-butadiene with stirring for 20–30 minutes. The reaction proceeds as follows: Rapid polymerization is carried out by continuous injection into the reactor, with the reaction occurring within 60-80 minutes. The initial feed rate is >7.0% mixture / min, and the rate of decrease depends on the reaction time. This process forms random, long, gradient segments –SB / (S→B)-. Then, the material in reactor B is added to reactor A. Simultaneously, in a 15L stainless steel reactor C, the system is purged with argon gas 2-4 times, and 100wt%-200wt% solvent and 10wt%-1,3-butadiene are added sequentially. 20 wt%, structure modifier 0.1 wt% to 0.3 wt%, second initiator, heat to 40 to 50 °C, react for 40 to 60 min to form -BR- segments until no free monomers are present, then add the material in reactor C to reactor A; finally heat reactor A to 80 to 90 °C, add coupling agent to carry out coupling reaction, react for 80 to 100 min, then treat the coupled reaction mixture with water, the gel is wet coagulated and dried to obtain the polymeric three-heteroarm brominated grafting agent.

[0045] (2) Preparation of Tri-Hybrid Fully Secondary Brominated Branched Butyl Rubber: Based on 100% of the total mass of the reactants, first, in a jacketed 4L stainless steel reactor, purge with nitrogen 3-5 times, then add 100wt%-200wt% mixed solvent (diluent / solvent V:V ratio of 70-30 / 30-70), 5wt%-10wt% high molecular weight tri-hybrid brominated grafting agent, and stir to dissolve for 70-90 minutes until the grafting agent is completely dissolved; then, when the temperature is lowered to -85 to -95℃, add 100wt%-200wt% diluent, 80wt%-90wt% isobutylene, and 5wt%-10wt% isoprene in sequence, stirring and mixing until the polymerization system temperature drops to -100 to -95℃, then add 10wt%-20wt% diluent and 0.2wt%-0.5wt% isoprene. After mixing and aging at -95 to -85°C for 60 to 70 minutes, 6% co-initiator is added to the polymerization system and stirred for 6.0 to 8.0 hours. Finally, 3 wt% to 7 wt% terminator is added, the mixture is discharged, coagulated, washed, and dried to obtain a tri-arm fully secondary brominated branched butyl rubber product.

[0046] The polymeric tri-heteroarm brominated grafting agent of the present invention is a tri-heteroarm fully secondary brominated star-shaped block copolymer composed of isoprene, 1,3-butadiene, styrene and a macromolecular composite brominated agent, and its general structural formula is shown in Formula I:

[0047]

[0048] Wherein, IR represents the isoprene homopolymer block; SB represents the random block of styrene and butadiene; (S→B) represents the graded block of styrene and butadiene; BR represents the 1,3-butadiene homopolymer block; m and n are the number of repeating units. The number-average molecular weight (Mn) of the polymeric tri-heteroarm brominated grafting agent is 50,000–70,000, and the molecular weight distribution (Mw / Mn) is 11.53–13.12.

[0049] This invention first involves the free radical polymerization of 1,2-dibromoethylene and bromovinylbenzene to generate a macromolecular composite brominating agent with anionic reactivity. Secondly, a reaction monomer composed of isoprene, styrene, 1,3-butadiene, and the macromolecular composite brominating agent is prepared through a three-stage reaction and temperature-variable polymerization process, and finally coupled with a trihalomethane coupling agent to produce a high-molecular-weight tri-heteroarm brominated grafting agent. Finally, using the high-molecular-weight tri-heteroarm brominated grafting agent, isobutylene, and isoprene as reaction monomers, a tri-heteroarm brominated branched butyl rubber with a fully secondary bromine structure and a wide molecular weight distribution is prepared through cationic polymerization.

[0050] The polymeric tri-arm brominated grafting agent of the present invention solves the problem of easy rearrangement of bromine structure in brominated branched butyl rubber, ensures the stability of secondary bromine structure, guarantees the scorch safety of butyl rubber, accelerates vulcanization speed, increases vulcanization degree, and improves vulcanization efficiency. Secondly, this polymeric tri-heteroarm brominated grafting agent employs a three-reactor polymerization and variable-speed polymerization process to obtain a tri-heteroarm star-shaped branched structure and highly random, gradient-segmented -SB / (S→B)-. This structural characteristic increases the disorder of molecular chain segments and significantly disrupts the regularity of the molecular chains during the grafting polymerization of butyl rubber, resulting in a significantly wider molecular weight distribution. This ensures that butyl rubber achieves good viscoelastic properties, possesses a fast stress relaxation rate, and improves the processing performance of butyl rubber. Finally, the -SB / (S→B)- segments in the polymeric tri-heteroarm brominated grafting agent and the macromolecular composite brominizing agent contain a certain amount of benzene rings. Benzene rings have high rigidity and large steric hindrance, which can prevent the decrease in strength and airtightness caused by the widening of the molecular weight distribution of butyl rubber, ensuring that butyl rubber has high strength and good airtightness.

[0051] Therefore, the polymeric tri-arm brominated grafting agent of the present invention organically combines the fully secondary bromine structure, the tri-arm star-shaped branched structure, and the SB / (S→B) segment, allowing them to work synergistically to achieve a balance in the vulcanization characteristics, processability, strength, and airtightness of butyl rubber, resulting in a more comprehensive improvement in the performance of butyl rubber. The method for preparing tri-arm fully secondary brominated branched butyl rubber provided by the present invention features a short process flow, controllable bromine structure, safety and environmental friendliness, and suitability for industrial production.

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

[0053] 1. The polymeric tri-arm brominated grafting agent of the present invention adopts free radical polymerization and anionic polymerization, rather than the ionic substitution reaction in the prior art, thereby avoiding the rearrangement of bromine structure in brominated branched butyl rubber, improving the stability of the all-secondary bromine structure in brominated branched butyl rubber, solving the problem of easy rearrangement of bromine structure in tri-arm all-secondary brominated branched butyl rubber, ensuring the stability of the all-secondary bromine structure, ensuring the scorch safety of butyl rubber, accelerating the vulcanization speed, increasing the degree of vulcanization, and improving the vulcanization efficiency.

[0054] 2. The macromolecular brominated grafting agent of the present invention first undergoes free radical polymerization of an organic brominated agent containing unsaturated double bonds to generate a macromolecular brominated agent, which then participates in anionic reactions. During the entire reaction process, HBr is not generated, thus avoiding the loss of other bromine, increasing the degree of reaction of the organic brominated agent, and improving the utilization rate of bromine in brominated branched butyl rubber.

[0055] 3. The macromolecular brominating agent of the present invention does not generate the byproduct HBr during the entire reaction process, which reduces the harm to humans and the environment, eliminates the need for alkaline washing and recovery of the byproduct HBr, thereby shortening the process and reducing production costs.

[0056] 4. The polymeric tri-arm brominated grafting agent of the present invention adopts a three-reactor polymerization and variable-speed polymerization process to obtain a tri-arm star-shaped branched structure and highly random, gradually changing chain segments -SB / (S→B)-. This structural feature increases the disorder of molecular chain segments and significantly destroys the regularity of molecular chains during the grafting polymerization of butyl rubber, resulting in a significantly wider molecular weight distribution. This ensures that butyl rubber can obtain good viscoelastic properties, has a fast stress relaxation rate, improves the processing performance of butyl rubber, and avoids the decrease in strength and air tightness caused by the widening of the molecular weight distribution of butyl rubber. It ensures that butyl rubber has high strength and good air tightness, and achieves a balance between the vulcanization characteristics and processability of butyl rubber and its strength and air tightness.

[0057] 5. The polymeric three-heteroarm brominated grafting agent of the present invention is a novel safe and environmentally friendly compound with no emissions of air pollutants (VOCs) and byproduct HBr. Its preparation method is green and environmentally friendly, with a short process flow, stable bromine structure, excellent processing performance, and is suitable for industrial production. Detailed Implementation

[0058] The following provides a detailed description of the embodiments of the present invention: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and processes. However, the scope of protection of the present invention is not limited to the following embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions.

[0059] (1) Source of raw materials:

[0060] Styrene, 1,3-butadiene, polymer grade, China National Petroleum Corporation Lanzhou Petrochemical Company;

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

[0062] Bromovinylbenzene, Polymerization Grade, Shanghai Yishi Chemical Co., Ltd.

[0063] 1,2-Dibromoethylene, Polymerization Grade, Shanghai Yishi Chemical Co., Ltd.

[0064] Dicumyl peroxide (DCP), Lanzhou Additives Factory;

[0065] n-Butyllithium, 98% purity, Nanjing Tonglian Chemical Co., Ltd.

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

[0067] Sesquiethylaluminum chloride, 98% purity, Bailingwei Technology Co., Ltd.

[0068] All other reagents are commercially available industrial products.

[0069] (2) Analysis and testing methods:

[0070] Bromine content determination: Weigh 10 mg of sample and use a Q600 TG / DTG thermogravimetric analyzer at a heating rate of 10℃ / min in a nitrogen atmosphere with a flow rate of 50 mL / min to perform thermal degradation of the sample. The first stage of thermal degradation involves 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] In the formula: Y is the percentage content of the sample at 220℃; 79.904 is the relative atomic mass of bromine; 1.008 is the relative atomic mass of hydrogen.

[0073] Molecular weight and its distribution were determined using a Waters 2414 gel permeation chromatography (GPC) system (USA). A polystyrene standard was used as the calibration curve. The mobile phase was tetrahydrofuran, the column temperature was 40℃, 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 determination: A GT-7080S2 Mooney viscometer was used, and the measurement was performed at 125℃ (1+8) using a large rotor, following the method in GB / T1232.1-2000. After the Mooney viscosity test, the rotor was stopped quickly (within 0.1 seconds), and the decrease in Mooney viscosity value over time was recorded. The torque within 0.1 seconds after the rotor stops was set as 100%, and the stress relaxation behavior of the rubber was expressed using t80 (the time it takes for 80% of the torque to decay (remaining 20%)) and X30 (the percentage of torque remaining 30 seconds after the rotor stops).

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

[0076] Air tightness determination: An automated air tightness tester was used to determine the air permeability number according to ISO 2782:1995.

[0077] The test gas was N2, the test temperature was 23℃, and the test sample was a circular sea sheet with a diameter of 8cm and a thickness of 1mm.

[0078] Tensile strength: The method specified in standard GB / T528-2009 shall be applied.

[0079] Example 1

[0080] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0081] Preparation of macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen gas was purged twice. Then, 2000g of octane, 700g of bromovinylbenzene, 300g of 1,2-dibromoethylene, and 2.0g of tert-dodecyl mercaptan were added to the reactor in sequence. The mixture was stirred and heated. When the reactor temperature reached 70℃, 3.0g of DCP was added and the reaction was carried out for 4.0hr. Then, 10g of 1,3-butadiene was added to the polymerization reactor for end-capping and the reaction was carried out for 50min until no free monomers were present. After the reaction was completed, the mixture was washed and dried to obtain the macromolecular composite brominating agent.

[0082] Preparation of the polymeric tri-heteroarm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon gas was purged twice. Then, 1000g octane, 200g isoprene, and 2.0g DME were added sequentially to the polymerization reactor. The temperature was raised to 60℃, and 11.3 mmol n-butyllithium was added to initiate the reaction for 40 minutes, forming -IR- segments. Next, 200g of the macromolecular composite brominizing agent was added to polymerization reactor A, and the reaction was continued for 70 minutes until no free monomers remained. Simultaneously, in a 15L stainless steel polymerization reactor B, the system was purged twice with argon gas. Then, 1000g octane, 3.0g DME, and 15.1 mmol n-butyllithium were added sequentially. The temperature was raised to 70℃, and then 200g styrene and 300g... 1,3-Butadiene was stirred and mixed for 30 minutes. During a 60-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 6 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged twice with argon gas, and 1000 g of heptane, 100 g of 1,3-butadiene, and 1.0 g of... DME was heated to 40°C, and 5.5 mmol of n-butyllithium was added to initiate a reaction for 40 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 80°C, and 35.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 80 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a high molecular weight tri-heteroarm brominated grafting agent (Mn = 52000, Mw / Mn = 11.53).

[0083] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: First, in a jacketed 4L stainless steel reactor, nitrogen was purged three times. Then, 350g of dichloromethane, 150g of hexane, and 25.0g of high-molecular-weight tri-arm brominated grafting agent were added to the polymerization reactor and stirred for 70 minutes until completely dissolved. The temperature was then lowered to -85℃, followed by the sequential addition of 500g of dichloromethane, 450g of isobutylene, and 25.0g of isoprene. The mixture was stirred until the polymerization system temperature dropped to -90℃. Then, 50g of dichloromethane, 1.52g of sesquiethylaluminum chloride, and 0.027g of HCl were mixed and aged at -85℃ for 60 minutes, and then added to the polymerization system. The mixture was stirred and reacted for 6.0 hours. Finally, 15g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the tri-arm fully secondary brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0084] Example 2

[0085] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0086] Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen gas was purged twice. Then, 2100g of octane, 720g of bromovinylbenzene, 280g of 1,2-dibromoethylene, and 2.5g of tert-dodecyl mercaptan were added to the reactor in sequence. The mixture was stirred and heated. When the reactor temperature reached 72℃, 3.5g of DCP was added, and the reaction was carried out for 4.5 hours. Then, 20g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 52 minutes until no free monomers were present. After the reaction was completed, the mixture was washed and dried to obtain the macromolecular composite brominating agent.

[0087] Preparation of the polymeric tri-heteroarm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon gas was purged twice. Then, 1100g of octane, 220g of isoprene, and 3.0g of DME were added sequentially to the polymerization reactor. The temperature was raised to 62℃, and 12.1 mmol of n-butyllithium was added to initiate the reaction for 45 minutes, forming -IR- segments. Next, 220g of the macromolecular composite brominizing agent was added to polymerization reactor A, and the reaction was continued for 75 minutes until no free monomers remained. Simultaneously, in a 15L stainless steel polymerization reactor B, the system was purged twice with argon gas. Then, 1100g of octane, 3.5g of DME, and 16.9 mmol of n-butyllithium were added sequentially. The temperature was raised to 72℃, and then 190g of styrene and 280g of... 1,3-Butadiene was stirred and mixed for 28 minutes. During a 60-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 6 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged twice with argon gas, and 1100 g of heptane, 110 g of 1,3-butadiene, and 1.3 g of... DME was heated to 45°C, and 6.8 mmol of n-butyllithium was added to initiate a reaction for 43 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 83°C, and 40.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 82 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a high molecular weight tri-heteroarm brominated grafting agent (Mn = 55000, Mw / Mn = 11.87).

[0088] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: First, in a jacketed 4L stainless steel reactor, nitrogen was purged three times. Then, 320g of dichloromethane, 180g of hexane, and 30.0g of high-molecular-weight tri-arm brominated grafting agent were added to the polymerization reactor and stirred for 75 minutes until completely dissolved. The temperature was then lowered to -87℃, followed by the sequential addition of 600g of dichloromethane, 440g of isobutylene, and 30.0g of isoprene. The mixture was stirred until the polymerization system temperature dropped to -92℃. Then, 60g of dichloromethane, 1.78g of sesquiethylaluminum chloride, and 0.035g of HCl were mixed and aged at -87℃ for 62 minutes, and then added to the polymerization system. The mixture was stirred and reacted for 6.4 hours. Finally, 20g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the tri-arm fully secondary brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0089] Example 3

[0090] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0091] Preparation of macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen gas was purged three times. Then, 2300g of octane, 740g of bromovinylbenzene, 260g of 1,2-dibromoethylene, and 3.0g of tert-dodecyl mercaptan were added to the reactor in sequence. The mixture was stirred and heated. When the reactor temperature reached 74℃, 4.0g of DCP was added, and the reaction was carried out for 5.0hr. Then, 30g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 54min until no free monomers were present. After the reaction was completed, the mixture was washed and dried to obtain the macromolecular composite brominating agent.

[0092] Preparation of the polymeric tri-heteroarm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon gas was purged three times. Then, 1400g of octane, 250g of isoprene, and 3.5g of DME were added sequentially to the polymerization reactor. The temperature was raised to 65℃, and 14.2 mmol of n-butyllithium was added to initiate the reaction for 50 minutes, forming -IR- segments. Next, 240g of the macromolecular composite brominizing agent was added to polymerization reactor A, and the reaction was continued for 80 minutes until no free monomers remained. Simultaneously, in a 15L stainless steel polymerization reactor B, the system was purged three times with argon gas. Then, 1300g of octane, 4.0g of DME, and 18.1 mmol of n-butyllithium were added sequentially. The temperature was raised to 75℃, and then 180g of styrene and 260g of... 1,3-Butadiene was stirred and mixed for 26 minutes. During a 70-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 4 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged three times with argon gas, and 1300 g of heptane, 140 g of 1,3-butadiene, and 1.7 g of... DME was heated to 45°C, and 7.5 mmol of n-butyllithium was added to initiate a reaction for 48 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 85°C, and 50.7 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 88 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a high molecular weight tri-heteroarm brominated grafting agent (Mn = 60000, Mw / Mn = 12.27).

[0093] (2) Preparation of Tri-Hybrid Fully Secondary Brominated Branched Butyl Rubber: First, in a jacketed 4L stainless steel reactor, nitrogen was purged four times. Then, 300g of dichloromethane, 200g of hexane, and 35.0g of high-molecular-weight tri-brittle brominated grafting agent were added to the polymerization reactor and stirred for 78 minutes until completely dissolved. The temperature was then lowered to -90℃, followed by the sequential addition of 700g of dichloromethane, 430g of isobutylene, and 35.0g of isoprene. The mixture was stirred until the polymerization system temperature dropped to -95℃. Then, 70g of dichloromethane, 2.18g of sesquiethylaluminum chloride, and 0.047g of HCl were mixed and aged at -90℃ for 64 minutes, and then added to the polymerization system. The mixture was stirred and reacted for 6.8 hours. Finally, 24g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the tri-brittle fully secondary brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0094] Example 4

[0095] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0096] Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen gas was purged three times. Then, 2500g of octane, 760g of bromovinylbenzene, 240g of 1,2-dibromoethylene, and 3.5g of tert-dodecyl mercaptan were added to the reactor in sequence. The mixture was stirred and heated. When the reactor temperature reached 76℃, 5.0g of DCP was added, and the reaction was carried out for 5.3 hours. Then, 40g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 56 minutes until no free monomers were present. After the reaction was completed, the mixture was washed and dried to obtain the macromolecular composite brominating agent.

[0097] Preparation of the polymeric tri-heteroarm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon gas was purged three times. Then, 1600g of octane, 260g of isoprene, and 4.0g of DME were added sequentially to the polymerization reactor. The temperature was raised to 66℃, and 16.8 mmol of n-butyllithium was added to initiate the reaction for 53 minutes, forming -IR- segments. Next, 260g of the macromolecular composite brominizing agent was added to polymerization reactor A, and the reaction was continued for 83 minutes until no free monomers remained. Simultaneously, in a 15L stainless steel polymerization reactor B, the system was purged three times with argon gas. Then, 1500g of octane, 4.5g of DME, and 19.7 mmol of n-butyllithium were added sequentially. The temperature was raised to 76℃, and then 170g of styrene and 240g of... 1,3-Butadiene was stirred and mixed for 24 minutes. During a 70-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 4 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged three times with argon gas, and 1600 g of heptane, 160 g of 1,3-butadiene, and 2.0 g of... DME was heated to 47°C, and 8.6 mmol of n-butyllithium was added to initiate a reaction for 52 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 87°C, and 60.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 92 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a high molecular weight tri-heteroarm brominated grafting agent (Mn = 63000, Mw / Mn = 12.58).

[0098] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: First, in a jacketed 4L stainless steel reactor, nitrogen was purged four times. Then, 300g of dichloromethane, 700g of hexane, and 40.0g of high-molecular-weight tri-arm brominated grafting agent were added to the polymerization reactor and stirred for 80 minutes until completely dissolved. The temperature was then lowered to -92℃, followed by the sequential addition of 800g of dichloromethane, 420g of isobutylene, and 40.0g of isoprene. The mixture was stirred until the polymerization system temperature dropped to -96℃. Then, 80g of dichloromethane, 2.35g of sesquiethylaluminum chloride, and 0.058g of HCl were mixed and aged at -92℃ for 66 minutes, and then added to the polymerization system. The mixture was stirred and reacted for 7.0 hours. Finally, 28g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the tri-arm fully secondary brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0099] Example 5

[0100] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0101] Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen gas was purged four times. Then, 2700g of octane, 780g of bromovinylbenzene, 220g of 1,2-dibromoethylene, and 4.0g of tert-dodecyl mercaptan were added to the reactor in sequence. The mixture was stirred and heated. When the reactor temperature reached 78℃, 6.0g of DCP was added, and the reaction was carried out for 5.7 hours. Then, 45g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 58 minutes until no free monomers were present. After the reaction was completed, the mixture was washed and dried to obtain the macromolecular composite brominating agent.

[0102] Preparation of the polymeric tri-heteroarm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon gas was purged four times. Then, 1800g of octane, 280g of isoprene, and 4.5g of DME were added sequentially to the polymerization reactor. The temperature was raised to 68℃, and 17.5mmol of n-butyllithium was added to initiate the reaction for 57 minutes, forming -IR- segments. Next, 280g of the macromolecular composite brominizing agent was added to polymerization reactor A, and the reaction was continued for 86 minutes until no free monomers remained. Simultaneously, in a 15L stainless steel polymerization reactor B, the system was purged with argon gas four times. Then, 1700g of octane, 5.0g of DME, and 21.5mmol of n-butyllithium were added sequentially. The temperature was raised to 78℃, and then 160g of styrene and 220g of... 1,3-Butadiene was stirred and mixed for 22 minutes. During an 80-minute reaction period, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 2 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged four times with argon gas, and 1800 g of heptane, 180 g of 1,3-butadiene, and 2.6 g of... DME was heated to 49°C, and 9.5 mmol of n-butyllithium was added to initiate a reaction for 57 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 89°C, and 80.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 95 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a high molecular weight tri-heteroarm brominated grafting agent (Mn = 67000, Mw / Mn = 12.89).

[0103] (2) Preparation of Tri-Hybrid Fully Secondary Brominated Branched Butyl Rubber: First, in a jacketed 4L stainless steel reactor, nitrogen was purged five times. Then, 500g of dichloromethane, 500g of hexane, and 45.0g of high-molecular-weight tri-brittle brominated grafting agent were added to the polymerization reactor and stirred for 84 minutes until completely dissolved. The temperature was then lowered to -94℃, and 900g of dichloromethane, 410g of isobutylene, and 45.0g of isoprene were added sequentially. The mixture was stirred until the polymerization system temperature dropped to -98℃. Then, 90g of dichloromethane, 2.63g of sesquiethylaluminum chloride, and 0.072g of HCl were mixed and aged at -94℃ for 68 minutes, and then added to the polymerization system. The mixture was stirred and reacted for 7.5 hours. Finally, 30g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the tri-brittle fully secondary brominated branched butyl rubber product. Sampling and Analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0104] Example 6

[0105] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0106] Preparation of a macromolecular composite brominating agent: First, in a 15L stainless steel reactor with a jacket, nitrogen gas was purged four times. Then, 300g of octane, 800g of bromovinylbenzene, 200g of 1,2-dibromoethylene, and 5.0g of tert-dodecyl mercaptan were added to the reactor in sequence. The mixture was stirred and heated. When the reactor temperature reached 80℃, 7.0g of DCP was added, and the reaction was carried out for 6.0hr. Then, 50g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was carried out for 60min until no free monomers were present. After the reaction was completed, the mixture was washed and dried to obtain the macromolecular composite brominating agent.

[0107] Preparation of the polymeric tri-heteroarm brominated grafting agent: First, in a 15L stainless steel reactor A with a jacket, argon gas was purged four times. Then, 2000g of octane, 300g of isoprene, and 5.0g of DME were added sequentially to the polymerization reactor. The temperature was raised to 70℃, and 18.6 mmol of n-butyllithium was added to initiate a reaction for 60 minutes to form -IR- segments. Next, 300g of macromolecular composite brominizing agent was added to polymerization reactor A, and the reaction was continued for 90 minutes until no free monomers remained. Simultaneously, in a 15L stainless steel polymerization reactor B, argon gas was purged four times. Then, 2000g of octane, 6.0g of DME, and 22.6 mmol of n-butyllithium were added sequentially. The temperature was raised to 80℃, and then 150g of styrene and 200g of... 1,3-Butadiene was stirred and mixed for 20 minutes. During an 80-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 2 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged four times with argon gas, and 2000 g of heptane, 200 g of 1,3-butadiene, and 3.0 g of... DME was heated to 50°C, and 10.6 mmol of n-butyllithium was added to initiate a reaction for 60 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 90°C, and 100.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 100 min, and then the coupled reaction mixture was treated with water. The gel was then wet-coagulated and dried to obtain a high molecular weight tri-heteroarm brominated grafting agent (Mn = 69000, Mw / Mn = 13.12).

[0108] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: First, nitrogen gas was purged five times in a 4L stainless steel reactor with a jacket. Then, 300g of dichloromethane, 700g of hexane, and 50.0g of high-molecular-weight tri-arm brominated grafting agent were added to the polymerization reactor and stirred for 90min until completely dissolved. Then, the temperature was lowered to -95℃, and 1000g of dichloromethane, 400g of isobutylene, and 50.0g of isoprene were added sequentially and stirred until the temperature of the polymerization system dropped to -100℃. Then, 100g of dichloromethane, 2.85g of sesquiethylaluminum chloride, and 0.085g of HCl were mixed and aged at -95℃ for 70min, and then added to the polymerization system and stirred for 8.0hr. Finally, 35g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the tri-arm fully secondary brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0109] Comparative Example 1

[0110] (1) Preparation of polymeric three-heteroarm brominated grafting agent:

[0111] Preparation of macromolecular composite brominator: Other conditions are the same as in Example 1, except that bromovinylbenzene is not added during the preparation of the macromolecular composite brominator. Specifically: First, in a 15L stainless steel reactor with a jacket, nitrogen is purged twice. Then, 2000g of octane, 300g of 1,2-dibromoethylene, and 2.0g of tert-dodecyl mercaptan are added to the reactor in sequence. The mixture is stirred and heated. When the reactor temperature reaches 70°C, 3.0g of DCP is added and the reaction is carried out for 4.0 hours. Then, 10g of 1,3-butadiene is added to the polymerization reactor for end-capping. The reaction is carried out for 50 minutes until no free monomers are present. After the reaction is completed, the mixture is washed and dried to obtain macromolecular composite brominator-1.

[0112] Preparation of the polymeric tri-heteroarm brominated grafting agent: Other conditions are the same as in Example 1, except that: no macromolecular composite brominizing agent is added during the preparation of the polymeric tri-heteroarm brominated grafting agent; instead, macromolecular composite brominizing agent-1 is added. That is: first, in a jacketed 15L stainless steel reactor A, argon gas is purged twice, and 1000g octane, 200g isoprene, and 2.0g DME are added sequentially to the polymerization reactor. The temperature is raised to 60°C, and 11.3 mmol n-butyllithium is added to start the reaction for 40 minutes to form -IR- segments. Then, 200g macromolecular composite brominizing agent-1 is added to polymerization reactor A, and the reaction is continued for 70 minutes until no free monomers are present. At the same time, in a 15L stainless steel polymerization reactor B, argon gas is purged twice, and 1000g octane, 3.0g DME, and 15.1 mmol n-butyllithium are added sequentially. The temperature is raised to 70°C, and then 200g styrene and 300g... 1,3-Butadiene was stirred and mixed for 30 minutes. During a 60-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 6 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged twice with argon gas, and 1000 g of heptane, 100 g of 1,3-butadiene, and 1.0 g of... DME was heated to 40°C, and 5.5 mmol of n-butyllithium was added to initiate a reaction for 40 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 80°C, and 35.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 80 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a polymeric tri-heteroarm brominated grafting agent-1 (Mn is 41000, Mw / Mn is 9.12).

[0113] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: Other conditions are the same as in Example 1, except that: no polymeric tri-arm brominated grafting agent is added during the preparation of the tri-arm fully secondary brominated branched butyl rubber. Instead, polymeric tri-arm brominated grafting agent-1 is added, with an addition amount of 25g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen is purged three times. Then, 350g of dichloromethane, 150g of hexane, and 25.0g of polymeric tri-arm brominated grafting agent-1 are added to the polymerization reactor. The mixture is stirred and dissolved for 70min until completely dissolved. Then, when the temperature is lowered to -85℃, 500g of dichloromethane, 450g of isobutylene, and 25.0g of isoprene are added sequentially. The mixture is stirred and mixed until the temperature of the polymerization system drops to -90℃. Then, 50g of dichloromethane, 1.52g of sesquiethylaluminum chloride, and HCl are added. 0.027g of the mixture was aged at -85℃ for 60 min, then added to the polymerization system and stirred for 6.0 hr. Finally, 15g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain a tri-arm fully secondary 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 polymeric three-heteroarm brominated grafting agent:

[0116] Preparation of macromolecular complex brominating agent: Same as in Example 2.

[0117] Preparation of the polymeric tri-heteroarm brominated grafting agent: Other conditions are the same as in Example 2, except that the amount of macromolecular composite brominated agent added in the preparation of the polymeric tri-heteroarm brominated grafting agent is 100g. That is: First, in a 15L stainless steel reactor A with a jacket, argon gas is purged twice, and 1100g of octane, 220g of isoprene, and 3.0g of DME are added sequentially to the polymerization reactor. The temperature is raised to 62°C, and 12.1 mmol of n-butyllithium is added to start the reaction for 45 min to form -IR- segments. Then, 100g of macromolecular composite brominated agent is added to polymerization reactor A, and the reaction is carried out for 75 min until no free monomers are present. At the same time, in a 15L stainless steel polymerization reactor B, argon gas is purged twice, and 1100g of octane, 3.5g of DME, and 16.9 mmol of n-butyllithium are added sequentially. The temperature is raised to 72°C, and then 190g of styrene and 280g of... 1,3-Butadiene was stirred and mixed for 28 minutes. During a 60-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 6 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged twice with argon gas, and 1100 g of heptane, 110 g of 1,3-butadiene, and 1.3 g of... DME was heated to 45°C, and 6.8 mmol of n-butyllithium was added to initiate a reaction for 43 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 83°C, and 40.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 82 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a polymeric tri-heteroarm brominated grafting agent-2 (Mn is 52000, Mw / Mn is 10.95).

[0118] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: Other conditions are the same as in Example 2, except that: no polymeric tri-arm brominated grafting agent is added during the preparation of the tri-arm fully secondary brominated branched butyl rubber. Instead, polymeric tri-arm brominated grafting agent-2 is added, with an addition amount of 30.0 g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged three times. Then, 320 g of dichloromethane, 180 g of hexane, and 30.0 g of polymeric tri-arm brominated grafting agent-2 are added to the polymerization reactor. The mixture is stirred and dissolved for 75 min until completely dissolved. Then, when the temperature is lowered to -87°C, 600 g of dichloromethane, 440 g of isobutylene, and 30.0 g of isoprene are added sequentially. The mixture is stirred and mixed until the temperature of the polymerization system drops to -92°C. Then, 60 g of dichloromethane, 1.78 g of sesquiethylaluminum chloride, and HCl are added. 0.035g of the mixture was aged at -87℃ for 62 minutes and then added to the polymerization system. After stirring for 6.4 hours, 20g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain a tri-arm fully secondary 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 polymeric three-heteroarm brominated grafting agent:

[0121] Preparation of macromolecular complex brominating agent: Same as in Example 3.

[0122] Preparation of the polymeric tri-hetero-arm brominated grafting agent: Other conditions are the same as in Example 3, except that no macromolecular composite brominating agent is added during the preparation of the polymeric tri-hetero-arm brominated grafting agent. Instead, bromovinylbenzene is added in an amount of 240g. Specifically: First, in a 15L stainless steel reactor A with a jacket, argon gas is purged three times. Then, 1400g of octane, 250g of isoprene, and 3.5g of DME are added sequentially to the polymerization reactor. The temperature is raised to 65°C, and 14.2 mmol of n-butyllithium is added to initiate the reaction for 50 minutes to form -IR- segments. Then, 240g of bromovinylbenzene is added to polymerization reactor A, and the reaction is continued for 80 minutes until no free monomers are present. Simultaneously, in a 15L stainless steel polymerization reactor B, argon gas is purged three times. Then, 1300g of octane, 4.0g of DME, and 18.1 mmol of n-butyllithium are added sequentially. The temperature is raised to 75°C, and then 180g of styrene and 260g of... 1,3-Butadiene was stirred and mixed for 26 minutes. During a 70-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 4 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged three times with argon gas, and 1300 g of heptane, 140 g of 1,3-butadiene, and 1.7 g of... DME was heated to 45°C, and 7.5 mmol of n-butyllithium was added to initiate a reaction for 48 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 85°C, and 50.7 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 88 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a polymeric tri-heteroarm brominated grafting agent-3 (Mn is 42000, Mw / Mn is 9.51).

[0123] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: Other conditions are the same as in Example 3, except that: no polymeric tri-arm brominated grafting agent is added during the preparation of the tri-arm brominated branched butyl rubber. Instead, polymeric tri-arm brominated grafting agent-3 is added, with an addition amount of 35.0 g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged four times. Then, 300 g of dichloromethane, 200 g of hexane, and 35.0 g of polymeric tri-arm brominated grafting agent-3 are added to the polymerization reactor. The mixture is stirred and dissolved for 78 min until it is completely dissolved. Then, when the temperature is lowered to -90°C, 700 g of dichloromethane, 430 g of isobutylene, and 35.0 g of isoprene are added sequentially. The mixture is stirred and mixed until the temperature of the polymerization system drops to -95°C. Then, 70 g of dichloromethane, 2.18 g of sesquiethylaluminum chloride, and HCl are added. 0.047g of the mixture was aged at -90℃ for 64 min, then added to the polymerization system and stirred for 6.8 h. Finally, 24g of ethanol was added, the mixture was discharged, coagulated, washed, and dried to obtain a tri-arm fully secondary 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 polymeric three-heteroarm brominated grafting agent:

[0126] Preparation of macromolecular complex brominating agent: Same as in Example 4.

[0127] Preparation of the polymeric tri-heteroarm brominated grafting agent: Other conditions are the same as in Example 4, except that no macromolecular composite brominating agent is added during the preparation of the polymeric tri-heteroarm brominated grafting agent. Instead, 1,2-dibromoethylene is added in an amount of 260g. Specifically: First, in a jacketed 15L stainless steel reactor A, argon gas is purged three times. Then, 1600g of octane, 260g of isoprene, and 4.0g of DME are added sequentially to the polymerization reactor. The temperature is raised to 66°C, and 16.8 mmol of n-butyllithium is added to initiate the reaction for 53 minutes to form -IR- segments. Then, 260g of 1,2-dibromoethylene is added to polymerization reactor A, and the reaction is continued for 83 minutes until no free monomers are present. Simultaneously, in a 15L stainless steel polymerization reactor B, argon gas is purged three times. Then, 1500g of octane, 4.5g of DME, and 16.8 mmol of DME are added sequentially to the polymerization reactor A. DME, 19.7 mmol n-butyllithium, heated to 76°C, then 170 g styrene and 240 g 1,3-butadiene were stirred and mixed for 24 min. During a 70 min reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 4 g / min, forming random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15 L stainless steel polymerization reactor C, the system was purged three times with argon gas, and 1600 g heptane, 160 g 1,3-butadiene, and 2.0 g... DME was heated to 47°C, and 8.6 mmol of n-butyllithium was added to initiate a reaction for 52 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 87°C, and 60.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 92 min, and then the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a polymeric tri-heteroarm brominated grafting agent-4 (Mn is 43000, Mw / Mn is 9.28).

[0128] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: Other conditions are the same as in Example 4, except that: no polymeric tri-arm brominated grafting agent is added during the preparation of the tri-arm fully secondary brominated branched butyl rubber. Instead, polymeric tri-arm brominated grafting agent-4 is added, with an addition amount of 40.0 g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged four times. Then, 300 g of dichloromethane, 700 g of hexane, and 40.0 g of polymeric tri-arm brominated grafting agent-4 are added to the polymerization reactor. The mixture is stirred and dissolved for 80 min until completely dissolved. Then, when the temperature is lowered to -92°C, 800 g of dichloromethane, 420 g of isobutylene, and 40.0 g of isoprene are added sequentially. The mixture is stirred and mixed until the temperature of the polymerization system drops to -96°C. Then, 80 g of dichloromethane, 2.35 g of sesquiethylaluminum chloride, and HCl are added. 0.058g of the mixture was aged at -92℃ for 66 min, then added to the polymerization system and stirred for 7.0 hr. Finally, 28g of ethanol was added, the mixture was discharged, coagulated, washed, and dried to obtain a tri-arm fully secondary 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 polymeric three-heteroarm brominated grafting agent:

[0131] Preparation of macromolecular complex brominating agent: Same as in Example 5.

[0132] Preparation of the polymeric tri-heteroarm brominated grafting agent: Other conditions are the same as in Example 5, except that variable-speed polymerization is not used in the polymerization reactor B during the preparation of the polymeric tri-heteroarm brominated grafting agent. That is: first, in the jacketed 15L stainless steel reactor A, argon gas is purged four times, and 1800g octane, 280g isoprene, and 4.5g DME are added to the polymerization reactor in sequence. The temperature is raised to 68°C, and 17.5mmol n-butyllithium is added to start the reaction for 57min to form -IR- segments. Then, 280g of macromolecular composite bromin is added to polymerization reactor A, and the reaction is carried out for 86min until no free monomers are present. At the same time, in the 15L stainless steel polymerization reactor B, argon gas is purged four times, and 1700g octane, 5.0g DME, and 21.5mmol n-butyllithium are added in sequence. The temperature is raised to 78°C, and then 160g styrene and 220g... After stirring and mixing 1,3-butadiene for 22 min, it was added to polymerization reactor B and reacted for 80 min to form -SBR- segments until no free monomers were present. Then, the material in polymerization reactor B was added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged with argon gas four times, and 1800g of heptane, 180g of 1,3-butadiene, and 2.6g of DME were added sequentially. The temperature was raised to 49℃, and 9.5 mmol of n-butyllithium was added to start the reaction for 57 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 89℃, and 80.5 mmol of 1,3,5-trichlorobenzene was added. The reaction was carried out for 95 min, and the coupled reaction mixture was treated with water. The gel was wet coagulated and dried to obtain a polymeric tri-heteroarm brominated grafting agent-5 (Mn = 65000, Mw / Mn = 8.21).

[0133] (2) Preparation of Tri-arm Fully Secondary Brominated Branched Butyl Rubber: Other conditions are the same as in Example 4, except that: no polymeric tri-arm brominated grafting agent is added during the preparation of the tri-arm fully secondary brominated branched butyl rubber. Instead, polymeric tri-arm brominated grafting agent-5 is added, with an addition amount of 45.0 g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged 5 times. Then, 500 g of dichloromethane, 500 g of hexane, and 45.0 g of polymeric tri-arm brominated grafting agent-5 are added to the polymerization reactor. The mixture is stirred and dissolved for 84 min until it is completely dissolved. Then, when the temperature is lowered to -94°C, 900 g of dichloromethane, 410 g of isobutylene, and 45.0 g of isoprene are added sequentially. The mixture is stirred and mixed until the temperature of the polymerization system drops to -98°C. Then, 90 g of dichloromethane, 2.63 g of sesquiethylaluminum chloride, and HCl are added. 0.072g of the mixture was aged at -94℃ for 68 min, then added to the polymerization system and stirred for 7.5 hr. Finally, 30g of ethanol was added, the mixture was discharged, coagulated, washed, and dried to obtain a tri-arm fully secondary 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] Preparation of macromolecular complex brominating agent: Same as in Example 6.

[0137] b. Preparation of the polymeric brominated grafting agent: Other conditions are the same as in Example 6, except that 1,3,5-trichlorobenzene is not added for coupling during the preparation of the polymeric brominated grafting agent. That is: First, in a jacketed 15L stainless steel reactor A, argon gas is purged four times. Then, 2000g of octane, 300g of isoprene, and 5.0g of DME are added sequentially to the polymerization reactor. The temperature is raised to 70°C, and 18.6 mmol of n-butyllithium is added to start the reaction for 60 minutes to form -IR- segments. Then, 300g of macromolecular composite bromin is added to polymerization reactor A, and the reaction is carried out for 90 minutes until no free monomers are present. At the same time, in a 15L stainless steel polymerization reactor B, argon gas is purged four times. Then, 2000g of octane, 6.0g of DME, and 22.6 mmol of n-butyllithium are added sequentially. The temperature is raised to 80°C, and then 150g of styrene and 200g of... 1,3-Butadiene was stirred and mixed for 20 minutes. During an 80-minute reaction time, the mixture was fed into the reactor at an initial rate of 70 g / min, decreasing by 2 g / min, to form random, long, gradient-segment -SB / (S→B)- chains until no free monomer remained. The material from polymerization reactor B was then added to polymerization reactor A. Simultaneously, in a 15L stainless steel polymerization reactor C, the system was purged four times with argon gas, and 2000 g of heptane, 200 g of 1,3-butadiene, and 3.0 g of... DME was heated to 50°C, and 10.6 mmol of n-butyllithium was added to initiate a reaction for 60 min to form -BR- segments until no free monomers were present. Then, the material in polymerization reactor C was added to polymerization reactor A. Finally, polymerization reactor A was heated to 90°C, and the coupled reaction mixture was treated with water. The gel was wet-coagulated and dried to obtain a high molecular weight brominated grafting agent-6 (Mn is 64000, Mw / Mn is 5.23). This high molecular weight brominated broad-distribution grafting agent-6 has no three-arm star-shaped branched structure.

[0138] (2) Preparation of fully secondary brominated branched butyl rubber: Other conditions are the same as in Example 6, except that: no polymeric tri-arm brominated grafting agent is added during the preparation of fully secondary brominated branched butyl rubber, but polymeric brominated grafting agent-6 is added, with an addition amount of 50.0g. That is: first, in a jacketed 4L stainless steel reactor, nitrogen gas is purged 5 times, and 300g of dichloromethane, 700g of hexane, and 50.0g of polymeric brominated grafting agent-6 are added to the polymerization reactor. The mixture is stirred and dissolved for 90min until it is completely dissolved. Then, when the temperature is lowered to -95℃, 1000g of dichloromethane, 400g of isobutylene, and 50.0g of isoprene are added in sequence. The mixture is stirred and mixed until the temperature of the polymerization system drops to -100℃. Then, 100g of dichloromethane, 2.85g of sesquiethylaluminum chloride, and HCl are added. 0.085g of the mixture was aged at -95℃ for 70 min, then added to the polymerization system and stirred for 8.0 hr. Finally, 35g of ethanol was added, the mixture was discharged, coagulated, washed, and dried to obtain the fully secondary brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test properties are shown in Table 1.

[0139] Table 1 Properties of Tri-arm Fully Secondary Brominated Branched Butyl Rubber

[0140]

[0141] Note: t 10 The scorching time reflects the size of the scorching safety window; t 90 The positive vulcanization time reflects the speed of vulcanization.

[0142] 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 short Mooney stress relaxation time, exhibiting good processing and vulcanization characteristics, while maintaining high tensile strength and good air tightness.

[0143] The above embodiments are typical examples listed to illustrate the technical solution of the present invention in detail. The present invention shall be subject to the protection scope of the claims and the invention content, and shall not be limited by the described embodiments. Simple substitutions or modifications to the present invention shall still be within the protection scope of the present invention.

Claims

1. A process for the preparation of a tri-hetero-armed, per-secondary, brominated branched butyl rubber, characterized in that, The preparation method includes the following steps: S1: Add the polymeric tri-arm brominated grafting agent to the mixed solvent and stir thoroughly until the polymeric tri-arm brominated grafting agent is completely dissolved to obtain a mixed solution; S2: Cool down, add diluent, isobutylene and isoprene to the mixed solution in step S1 in sequence, stir and mix thoroughly to obtain the polymerization reaction system, and cool down again; S3: Mix the diluent and co-initiator and age them. Then add them to the polymerization reaction system of step S2 and stir the reaction thoroughly. Add the terminator, discharge the material, coagulate, wash and dry to obtain the three hetero-arm fully secondary brominated branched butyl rubber. The preparation method of the polymeric three-heteroarm brominated grafting agent specifically includes the following steps: Preparation of a macromolecular composite brominating agent: Taking 100 parts by mass of reactive brominating agent, firstly, add 200-300 parts of solvent, 70-80 parts of bromovinylbenzene, 20-30 parts of 1,2-dibromoethylene, and 0.2-0.5 parts of molecular weight regulator sequentially to a reaction vessel after inert gas replacement. Stir and mix, heat, and when the reaction vessel temperature reaches 70-80℃, add 0.3-0.7 parts of the first initiator. React for 4.0-6.0 h, at which point the conversion rate of bromovinylbenzene reaches 100%. Then, add 1-5 parts of 1,3-butadiene to the reaction vessel for end-capping, and react for 50-60 min until no free monomers are present. After the reaction is completed, wash and dry to obtain the macromolecular composite brominating agent. Preparation of the high-molecular-weight tri-hetero-arm brominated grafting agent: Based on 100% of the total mass of the reactants, first, add 100 wt%~200 wt% solvent, 20 wt%~30 wt% isoprene, 0.2 wt%~0.5 wt% structure modifier, and a second initiator sequentially to reactor A after inert gas purging. Heat to 60~70℃ and react for 40~60 min to form -IR- segments, where IR represents the isoprene homopolymer block. Then, add 20 wt%~30 wt% macromolecular composite brominating agent to reactor A and react for 70~90 min until no free monomers remain. Simultaneously, add 100 wt%~200 wt% solvent, 0.3 wt%~0.6 wt% structure modifier, and a second initiator sequentially to reactor B after inert gas purging. Heat to 70~80℃ and add 15 wt%~20 wt% styrene... 20 wt%~30 wt% of 1,3-butadiene were stirred and mixed for 20~30 min. The reaction was a variable-speed polymerization, with the mixture continuously added to the reactor. The reaction was carried out over 60 min~80 min, with an initial feed rate >7.0% of the mixture / min. The feed rate was reduced according to the reaction time, forming random, long gradient segments -SB / (S→B)-. SB is the random segment of styrene and butadiene, and (S→B) is the gradient segment of styrene and butadiene. Then, the material in reactor B was added to reactor A. Simultaneously, in a 15L stainless steel reactor C, the system was purged with argon gas 2~4 times. 100 wt%~200 wt% of solvent, 10 wt%~20 wt% of 1,3-butadiene, and 0.1 wt%~0.3 wt% of structure modifier were added sequentially. The second initiator is heated to 40-50℃ and reacted for 40-60 minutes to form -BR- segments until no free monomers are present. Then, the material in reactor C is added to reactor A. Finally, reactor A is heated to 80-90℃, and a coupling agent is added to carry out the coupling reaction. After reacting for 80-100 minutes, the coupled reaction mixture is treated with water. The resulting reaction mixture is then subjected to wet coagulation and drying to obtain a high molecular weight three-heteroarm brominated grafting agent. The number-average molecular weight (Mn) of the polymeric tri-arm brominated grafting agent is 50,000 to 70,000, and the molecular weight distribution (Mw / Mn) is 11.53 to 13.

12.

2. The method for preparing the three-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, In step S1, the mass ratio of the mixed solvent to the polymeric tri-arm brominated grafting agent is 100~200:5~10; in step S1, the mixed solvent includes a diluent and a solvent, and the volume ratio of the diluent to the solvent is 70~30 / 30~70.

3. The method for preparing the three-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, In step S2, the temperature is cooled to -85~-95℃, and the temperature is cooled again to -100~-95℃.

4. The method for preparing the three-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, In step S2, the mass ratio of the diluent, isobutylene, and isoprene is 100~200:80~90:5~10.

5. The method for preparing the three-hetero-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, In step S3, the mass ratio of the diluent, co-initiator, and terminator is 10~20:0.2~0.6:3~7.

6. The method for preparing the three-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, The molecular weight regulator is selected from at least one of tert-decanethiol, tert-dodecanethiol, tert-tetradecanethiol, and tert-hexadecanethiol; The first initiator is an organic peroxide, selected from at least one of dicumyl peroxide (DCP), cumyl hydroperoxide, benzoyl peroxide (BPO), and di-tert-butyl peroxide; The structure modifier is a polar organic compound selected from at least one of diethylene glycol dimethyl ether, tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether, and triethylamine. The second initiator is a hydrocarbon-based monolithium compound RLi, selected from at least one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium, and dodecyllithium.

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

1.

8. The method for preparing the three-hetero-arm fully secondary brominated branched butyl rubber according to claim 1 or 2, characterized in that, The solvent is selected from at least one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene, and ethylbenzene.

9. The method for preparing the three-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, The diluent is a haloalkane, selected from at least one of chloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, fluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane.

10. The method for preparing the three-hetero-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, The co-initiator is composed of an alkyl aluminum halide and a protic acid in a specific ratio; the alkyl aluminum halide is selected from at least one of diethylaluminum chloride, diisobutylaluminum chloride, dichloromethylaluminum, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, dichloro-n-propylaluminum, dichloroisopropylaluminum, dimethylaluminum chloride, and ethylaluminum chloride; the protic acid is selected from one of HCl, HF, HBr, H2SO4, H2CO3, H3PO4, and HNO3; the molar ratio of the protic acid to the alkyl aluminum halide is 0.05:1 to 0.5:

1.

11. The method for preparing the three-hetero-arm fully secondary brominated branched butyl rubber according to claim 1, characterized in that, The terminating agent is at least one of methanol, ethanol, and butanol.

Images