Preparation of high molecular composite damping brominated grafting agent and brominated branched butyl rubber

Abstract

The application discloses a high-molecular composite damping brominated grafting agent and a preparation method thereof. The high-molecular composite damping brominated grafting agent is a linear isotactic block copolymer composed of isocyanyl alkyl methacrylate, unsaturated carboxylic acid, 3,5-dibromostyrene and para-alkyl styrene. The application further discloses a method for preparing brominated branched butyl rubber. The method for preparing the brominated branched butyl rubber with wide temperature range and high damping has the characteristics of green environmental protection, stable product quality, easy availability of raw materials, and convenient industrial production.

Description

Technical Field

[0001] This invention relates to a polymeric composite damping brominated grafting agent and the preparation of a wide-temperature-range, high-damping brominated branched butyl rubber. Background Technology

[0002] With the rapid development of modern science and technology, mechanical equipment in many fields, such as high-speed rail, aerospace, naval vessels, mechanical engineering, automobiles, and electronics, is trending towards high frequency and high speed. While bringing convenience to daily production and life, this has also generated a series of problems, such as high-frequency vibration and noise. These problems not only accelerate the fatigue damage of mechanical structural materials and shorten their service life, but also pose an increasingly prominent threat to people's lives and property. Vibration reduction and noise reduction have become one of the most pressing problems to be solved in today's society. Therefore, developing high-performance, high-efficiency damping materials and improving their application in damping and vibration reduction is crucial for improving the operating environment of machinery and for human health and safety.

[0003] Brominated butyl rubber (BIIR) is produced by electrophilic substitution of bromine atoms into the molecular chain of butyl rubber (IIR) under the influence of molecular bromine. Compared to IIR, BIIR, in addition to possessing the same excellent airtightness, also exhibits better adhesion, faster vulcanization speed, good thermal stability, and corrosion resistance, enabling its use in extreme environments such as strong corrosion or high temperatures. Furthermore, the introduction of bromine atoms increases the polarity of the molecular chain, leading to increased relaxation resistance and greater internal friction, resulting in excellent damping performance. Therefore, it is one of the most widely used basic damping rubbers. Currently, in practical applications, damping functionality is often required within the temperature range of -50℃ to +50℃. However, the effective damping functional region (damping factor tanδ > 0.3) of brominated butyl rubber is currently concentrated in the low-temperature range, with damping values ​​being relatively low above 15℃. This fails to adequately meet the requirements for wide-temperature-range damping materials. Therefore, expanding the effective damping functional region of butyl rubber above room temperature is one of the current research hotspots in rubber damping materials.

[0004] In the prior art, the preparation methods of wide temperature range, high damping rubber materials mainly include blending, copolymerization, interpenetrating polymer networks, and adding organic small molecule functional damping agents.

[0005] Literature such as CN112574333A, CN102775659B, CN 106749816A, CN113969031A, CN103113682A, CN103113682A, as well as Tao Gang et al. (Polymer Materials Science and Engineering, 2013, 29(11): 114-118) and Liao Mingyi et al. (Journal of Dalian Maritime University, 2008, 34(2): 83-86) have shown that blending, copolymerization, and interpenetrating polymer networks can broaden the effective damping temperature range of rubber and improve its damping performance to a certain extent. However, these methods still have certain limitations, which can lead to a decrease in the mechanical properties of modified materials, complex processes, difficult practical operation, large addition amounts, high costs, difficulty in removing organic solvents, and environmental pollution. Summary of the Invention

[0006] One of the objectives of this invention is to provide a maximum damping factor tanδ max A method for preparing a wide-temperature-range, high-damping brominated branched butyl rubber with an effective damping temperature range (tanδ≥0.3) that meets the requirements for use within the range of -75℃ to 83℃. This invention first uses anionic polymerization to synthesize a macromolecular composite functional brominator from unsaturated carboxylic acid, isocyanoalkyl methacrylate, and 3,5-dibromostyrene monomers; secondly, it synthesizes a functional polymeric composite damping brominated grafting agent from the macromolecular composite functional brominator and p-alkylstyrene; finally, it prepares a wide-temperature-range, high-damping brominated branched butyl rubber by cationic polymerization of the functional polymeric composite damping brominated grafting agent with isobutylene and isoprene. This method directly embeds the functionalized groups cyano, carboxyl, and bromine atoms into the butyl rubber chain structure through anionic reactions, rather than the free radical substitution reactions used in existing technologies, to form an interpenetrating polymer network (IPN), thus endowing the brominated branched butyl rubber with a wider effective damping temperature range and higher damping performance.

[0007] In this invention, "%" refers to mass percentage.

[0008] As one aspect of the present invention, a polymeric composite damping brominated grafting agent is disclosed, which is a linear isotactic block copolymer composed of isocyanate alkyl methacrylate, unsaturated carboxylic acid, 3,5-dibromostyrene, and p-alkylstyrene, and its general structural formula is shown in Formula I:

[0009]

[0010] Wherein: I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is a C1-C4 alkyl group; n and m are the number of repeating units: n≥1, m≥1. The polymeric composite functional brominated grafting agent has a number-average molecular weight (Mn) of 50,000-60,000, a molecular weight distribution (Mw / Mn) of 1.51-1.91, and a bromine content of 5.12%-6.01% by mass.

[0011] As another aspect of the present invention, a method for preparing the above-mentioned functional polymeric composite damping brominated grafting agent is provided, comprising:

[0012] Based on 100% by mass of the reactant monomer 3,5-dibromostyrene, 200%–300% solvent, 100% 3,5-dibromostyrene, and 0.4%–0.6% structure modifier were added sequentially to a polymerization reactor. The temperature was raised to 70–80°C, and an initiator was added, reacting for 80–90 minutes. Then, 20%–30% isocyanate alkyl methacrylate and 0.3%–0.4% structure modifier were added, reacting for 50–60 minutes. Next, 10%–20% unsaturated carboxylic acid and 0.2%–0.3% structure modifier were added, reacting for 30–40 minutes. Finally, 1.0%–3.0% 1,3-butadiene was added for end-capping, reacting for 20–30 minutes until no free monomer remained. After the reaction was complete, the product was washed and dried to obtain a macromolecular composite functional brominating agent.

[0013] Based on 100% of the total mass of the macromolecular composite functional brominating agent and p-alkylstyrene, 200%–300% solvent, 70%–80% p-alkylstyrene, and 0.4%–0.6% structure modifier are sequentially added to the polymerization reactor. After heating to 70–80°C, an initiator is added and the reaction proceeds for 90–110 min. Next, 20%–30% of the macromolecular composite functional brominating agent and 0.2%–0.4% of the structure modifier are added to the polymerization reactor, and the temperature is raised to 80–90°C, reacting for 60–70 min. Finally, 2.0%–3.0% isoprene is added to the polymerization reactor for end-capping, and the reaction proceeds for 20–30 min until no free monomers remain. The resulting solution is then wet-coagulated and dried to obtain a functional polymeric composite damping brominated grafting agent. Preferably, the reactor is purged with argon gas 2–4 times before adding the reactants.

[0014] As another aspect of the present invention, a method for preparing brominated branched butyl rubber is provided, comprising:

[0015] Based on 100% by mass of the reactant isobutylene, first, in a jacketed 4L stainless steel reactor, purge with nitrogen 3-5 times. Add 100%-200% mixed solvent (diluent / solvent V:V ratio of 70-30 / 30-70), 3%-5% functional polymer composite damping brominated grafting agent, and stir to dissolve for 50-60 minutes until the grafting agent is completely dissolved. Then, lower the temperature to -80 to -70℃, and then sequentially add 100%-200% diluent, 100% isobutylene, and 4%-6% isoprene. Stir and mix until the polymerization system temperature drops to -90 to -80℃. Then, add 10%-20% diluent and 0.2%... ~0.4% co-initiator was mixed and aged at -100 to -90℃ for 40 to 50 minutes, then added to the polymerization system and stirred for 4.0 to 5.0 hours. Finally, 3% to 5% terminator was added, and the mixture was discharged, coagulated, washed, and dried to obtain a wide-temperature-range, high-damping brominated branched butyl rubber.

[0016] The isocyanate alkyl methacrylate described in this invention is one of methyl isocyanate methacrylate, ethyl isocyanate methacrylate, propyl isocyanate methacrylate, butyl isocyanate methacrylate, and isobutyl isocyanate methacrylate, preferably methyl isocyanate methacrylate.

[0017] The unsaturated carboxylic acid described in this invention is one of acrylic acid (AA), methacrylic acid (MAA), and maleic anhydride (MAH), with MAA being preferred.

[0018] The p-alkylstyrene described in this invention is one of p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-n-butylstyrene, and p-isobutylstyrene, with p-methylstyrene being preferred.

[0019] The initiator described in this invention is a hydrocarbon-based monolithium compound, namely RLi, wherein R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic group, or a complex group containing 1 to 20 carbon atoms. This hydrocarbon-based monolithium compound is selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthenelithium, cyclohexyllithium, and dodecyllithium, preferably n-butyllithium. The amount of organolithium added is determined by the molecular weight of the designed polymer.

[0020] The structure modifier described in this invention is a polar organic compound that produces a solvation effect in the polymerization system, enabling it to adjust the reactivity ratio of styrene and isoprene, thus allowing them to copolymerize randomly. This type of polar organic compound is selected from 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 tetrahydrofuran (THF).

[0021] The diluent described in this invention is a haloalkane, wherein the halogen atom in the haloalkane can be chlorine, bromine, or fluorine; the number of carbon atoms in the haloalkane is C1-C4. This haloalkane is selected from one of chloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, fluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane, preferably chloromethane.

[0022] The co-initiator described in this invention is composed of alkyl aluminum halides and protic acids 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 total amount of co-initiator added is 0.1% to 0.5%, and the molar ratio of protic acid to alkyl aluminum halide is 0.01:1 to 0.1:1.

[0023] The terminating agent described in this invention may be selected from one or more of methanol, ethanol, and butanol.

[0024] The polymerization reactions described in this invention are all carried out in an oxygen-free and anhydrous environment, preferably in an inert gas environment. Both the polymerization and dissolution processes are completed in a hydrocarbon solvent. The solvent described in this invention is a hydrocarbon solvent, including straight-chain alkanes, aromatics, and cycloalkanes. This hydrocarbon solvent is selected from one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene, and ethylbenzene, with cyclohexane being preferred.

[0025] The macromolecular composite functional brominizing agent prepared in this invention combines two highly and moderately polar monomers, unsaturated carboxylic acids and isocyanate alkyl methacrylate, with the brominizing agent 3,5-dibromostyrene via anionic polymerization onto a single macromolecular chain. This generates a significant "stacking effect" of polar groups when improving the effective damping temperature range of the material, which can greatly enhance the effective damping temperature range of brominated branched butyl rubber. An effective damping temperature range (tanδ≥0.3) can be prepared that meets the requirements for use in the range of -75℃ to 83℃.

[0026] The functional polymeric composite damping brominated grafting agent prepared in this invention is produced through anionic polymerization. It utilizes p-alkylstyrene and a macromolecular composite functional brominated agent to polymerize a high molecular weight, narrow molecular weight distribution, and high isotacticity block copolymer containing bromine atoms, cyano groups, and carboxyl groups. This functional polymeric composite damping brominated grafting agent, leveraging the superimposed characteristics of "group effect" and "structural effect," can significantly improve the damping performance of brominated branched butyl rubber, and can produce a maximum damping factor tan δ. max≥2.4, wide temperature range, high damping brominated branched butyl rubber.

[0027] The wide-temperature-range, high-damping brominated branched butyl rubber prepared by this invention is obtained directly from a functional polymer composite damping brominated grafting agent via cationic polymerization in a one-step process. This eliminates the need for a bromination process and results in no emissions of volatile organic compounds (VOCs) or the byproduct HBr. This brominated branched butyl rubber not only broadens the effective damping temperature range but also avoids the degradation of damping properties, mechanical properties, and airtightness.

[0028] The present invention provides a method for preparing wide-temperature-range, high-damping brominated branched butyl rubber, which is characterized by being green and environmentally friendly, producing stable product quality, using readily available raw materials, and facilitating industrial production. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] (1) Source of raw materials:

[0031]

[0032] All other reagents are commercially available industrial products.

[0033] (2) Analysis and testing methods:

[0034] 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 .

[0035] 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:

[0036]

[0037] In the formula: Y—percentage content of the sample at 220℃; 79.904—relative atomic mass of bromine; 1.008—relative atomic mass of hydrogen.

[0038] Molecular weight determination: Molecular weight was determined using a Waters 2414 gel permeation chromatography (GPC) system (Waters, Inc., 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.

[0039] Air tightness determination: An automated air tightness tester was used to determine the air permeability number according to ISO 2782:1995.

[0040] 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.

[0041] Dynamic mechanical analysis (DMA): Measurements were performed in tensile mode on a Netzsch 242C dynamic mechanical analyzer (Germany). Sample dimensions were 10 mm long, 6 mm wide, and 2 mm thick. The temperature range was -90℃ to 90℃, with a heating rate of 3℃ / min. Data were analyzed at a frequency of 10 Hz.

[0042] Tensile strength: The method specified in standard GB / T528-2009 shall be applied.

[0043] Example 1

[0044] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0045] Preparation of a macromolecular composite functional brominator: First, in a 15L stainless steel reactor with a jacket, argon gas was purged three times. Then, 2000g of cyclohexane, 1000g of 3,5-dibromostyrene, and 4.0g of THF were added sequentially to the polymerization reactor. After heating to 70℃, 5.9 mmol of n-butyllithium was added to initiate the reaction for 80 min. Next, 200g of isocyanate methacrylate and 3.0g of THF were added to the polymerization reactor, and the reaction was continued for 50 min. Then, 100g of methacrylic acid and 2.0g of THF were added to the polymerization reactor, and the reaction was continued for 30 min. Finally, 10g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 20 min until no free monomers remained. After the reaction was completed, the product was washed and dried to obtain the macromolecular composite functional brominator.

[0046] Preparation of functional polymer composite damping brominated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon gas was purged three times. Then, 2000g of cyclohexane, 800g of p-methylstyrene, and 6.0g of THF were added sequentially to the polymerization reactor. After heating to 70℃, 26.1 mmol of n-butyllithium was added to initiate a reaction for 90 min. Next, 200g of macromolecular composite functional brominated agent and 2.0g of THF were added to the polymerization reactor, and the temperature was raised to 80℃ for a reaction of 60 min. Finally, 20g of isoprene was added to the polymerization reactor for end-capping, and the reaction was continued for 20 min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functional polymer composite damping brominated grafting agent (Mn = 51300, Mw / Mn = 1.51, bromine content = 5.12%). The functional polymer composite damping brominated grafting agent obtained in this embodiment, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0047] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen gas was purged three times. Then, 350g of dichloromethane, 150g of cyclohexane, and 15g of functional polymer composite damping brominated grafting agent were added to the polymerization reactor and stirred for 50min until completely dissolved. Then, when the temperature was lowered to -70℃, 500g of monochloromethane, 500g of isobutylene, and 20g of isoprene were added sequentially and stirred until the temperature of the polymerization system dropped to -80℃. Then, 50g of monochloromethane, 1.09g of sesquiethylaluminum chloride, and 0.013g of HCl were mixed and aged at -90℃ for 40min, and then added to the polymerization system and stirred for 4.0hr. Finally, 15g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0048] Example 2

[0049] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0050] Preparation of a macromolecular composite functional brominator: First, in a 15L stainless steel reactor with a jacket, argon gas was purged three times. Then, 2300g of cyclohexane, 1000g of 3,5-dibromostyrene, and 4.5g of THF were added sequentially to the polymerization reactor. After heating to 72℃, 6.3 mmol of n-butyllithium was added to initiate a reaction for 83 min. Next, 230g of isocyanate methacrylate and 3.3g of THF were added to the polymerization reactor, and the reaction was continued for 53 min. Then, 130g of methacrylic acid and 2.4g of THF were added to the polymerization reactor, and the reaction was continued for 33 min. Finally, 15g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 23 min until no free monomers remained. After the reaction was completed, the product was washed and dried to obtain the macromolecular composite functional brominator.

[0051] Preparation of functional polymer composite damping brominated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon gas was purged three times. Then, 2300g of cyclohexane, 770g of p-methylstyrene, and 5.5g of THF were added sequentially to the polymerization reactor. After heating to 73℃, 26.7 mmol of n-butyllithium was added to initiate a reaction for 95 min. Next, 230g of macromolecular composite functional brominated agent and 2.5g of THF were added to the polymerization reactor, and the temperature was raised to 83℃ for a reaction of 63 min. Finally, 22g of isoprene was added to the polymerization reactor for end-capping, and the reaction was continued for 23 min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functional polymer composite damping brominated grafting agent (Mn = 54000, Mw / Mn = 1.65, bromine content = 5.36%). The functional polymer composite damping brominated grafting agent obtained in this embodiment, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0052] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen gas was purged three times. 290g of dichloromethane, 210g of cyclohexane, and 18g of functional polymer composite damping brominated grafting agent were added to the polymerization reactor and stirred for 53min until completely dissolved. Then, when the temperature was lowered to -73℃, 600g of monochloromethane, 500g of isobutylene, and 22g of isoprene were added sequentially and stirred until the polymerization system temperature dropped to -83℃. Then, 60g of monochloromethane, 1.21g of sesquiethylaluminum chloride, and 0.035g of HCl were mixed and aged at -92℃ for 43min, and then added to the polymerization system and stirred for 4.3hr. Finally, 18g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0053] Example 3

[0054] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0055] Preparation of a macromolecular composite functional brominator: First, in a 15L stainless steel reactor with a jacket, argon gas was purged four times. Then, 2500g of cyclohexane, 1000g of 3,5-dibromostyrene, and 5.0g of THF were added sequentially to the polymerization reactor. After heating to 75℃, 7.1 mmol of n-butyllithium was added to initiate a reaction for 85 min. Next, 250g of isocyanate methacrylate and 3.5g of THF were added to the polymerization reactor, and the reaction was continued for 56 min. Then, 160g of methacrylic acid and 2.6g of THF were added to the polymerization reactor, and the reaction was continued for 35 min. Finally, 20g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 26 min until no free monomers remained. After the reaction was completed, the product was washed and dried to obtain the macromolecular composite functional brominator.

[0056] Preparation of functional polymer composite damping brominated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon gas was purged four times. Then, 2500g of cyclohexane, 750g of p-methylstyrene, and 5.0g of THF were added sequentially to the polymerization reactor. After heating to 75℃, 27.8 mmol of n-butyllithium was added to initiate a reaction for 100 min. Next, 260g of macromolecular composite functional brominated agent and 3.0g of THF were added to the polymerization reactor, and the temperature was raised to 86℃ for a reaction of 65 min. Finally, 25g of isoprene was added to the polymerization reactor for end-capping, and the reaction was continued for 26 min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functional polymer composite damping brominated grafting agent (Mn = 56000, Mw / Mn = 1.78, bromine content = 5.61%). The functional polymer composite damping brominated grafting agent obtained in this embodiment, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0057] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen gas was purged three times. 700g of dichloromethane, 300g of cyclohexane, and 21g of functional polymer composite damping brominated grafting agent were added to the polymerization reactor and stirred for 55min until completely dissolved. Then, when the temperature was lowered to -75℃, 700g of monochloromethane, 500g of isobutylene, and 25g of isoprene were added sequentially and stirred until the polymerization system temperature dropped to -85℃. Then, 80g of monochloromethane, 1.41g of sesquiethylaluminum chloride, and 0.055g of HCl were mixed and aged at -95℃ for 45min, and then added to the polymerization system and stirred for 4.6hr. Finally, 20g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0058] Example 4

[0059] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0060] Preparation of a macromolecular composite functional brominator: First, in a 15L stainless steel reactor with a jacket, argon gas was purged four times. Then, 2700g of cyclohexane, 1000g of 3,5-dibromostyrene, and 5.6g of THF were added sequentially to the polymerization reactor. After heating to 77℃, 8.2 mmol of n-butyllithium was added to initiate the reaction for 87 min. Next, 280g of isocyanate methacrylate and 3.7g of THF were added to the polymerization reactor, and the reaction was continued for 58 min. Then, 180g of methacrylic acid and 2.8g of THF were added to the polymerization reactor, and the reaction was continued for 37 min. Finally, 26g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 28 min until no free monomers remained. After the reaction was completed, the product was washed and dried to obtain the macromolecular composite functional brominator.

[0061] Preparation of functional polymer composite damping brominated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon gas was purged four times. Then, 2700g of cyclohexane, 730g of p-methylstyrene, and 4.4g of THF were added sequentially to the polymerization reactor. After heating to 77℃, 28.3 mmol of n-butyllithium was added to initiate the reaction for 106 min. Next, 280g of macromolecular composite functional brominated agent and 3.5g of THF were added to the polymerization reactor, and the temperature was raised to 88℃ for 67 min. Finally, 28g of isoprene was added to the polymerization reactor for end-capping, and the reaction continued for 28 min until no free monomers remained. The resulting solution was wet-coagulated and dried to obtain the functional polymer composite damping brominated grafting agent (Mn = 58000, Mw / Mn = 1.84, bromine content = 5.87%). The functional polymer composite damping brominated grafting agent obtained in this embodiment, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0062] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen gas was purged three times. 500g of dichloromethane, 500g of cyclohexane, and 23g of functional polymer composite damping brominated grafting agent were added to the polymerization reactor and stirred for 57min until completely dissolved. Then, when the temperature was lowered to -78℃, 900g of monochloromethane, 500g of isobutylene, and 28g of isoprene were added sequentially and stirred until the polymerization system temperature dropped to -87℃. Then, 90g of monochloromethane, 1.64g of sesquiethylaluminum chloride, and 0.073g of HCl were mixed and aged at -97℃ for 48min, and then added to the polymerization system and stirred for 4.8hr. Finally, 23g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0063] Example 5

[0064] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0065] Preparation of a macromolecular composite functional brominator: First, in a 15L stainless steel reactor with a jacket, argon gas was purged five times. Then, 3000g of cyclohexane, 1000g of 3,5-dibromostyrene, and 6.0g of THF were added sequentially to the polymerization reactor. After heating to 80℃, 8.8mmol of n-butyllithium was added to initiate a reaction for 90min. Subsequently, 300g of isocyanate butyl methacrylate and 4.0g of THF were added to the polymerization reactor, and the reaction was continued for 60min. Then, 200g of methacrylic acid and 3.0g of THF were added to the polymerization reactor, and the reaction was continued for 40min. Finally, 30g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 30min until no free monomers were present. After the reaction was completed, the product was washed and dried to obtain the macromolecular composite functional brominator.

[0066] Preparation of functional polymer composite damping brominated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon gas was purged five times. Then, 3000g of cyclohexane, 700g of p-n-butylstyrene, and 4.0g of THF were added sequentially to the polymerization reactor. After heating to 80℃, 29.5mmol of n-butyllithium was added to initiate the reaction for 110min. Next, 300g of macromolecular composite functional brominated agent and 4.0g of THF were added to the polymerization reactor, and the temperature was raised to 90℃ for 70min. Finally, 30g of isoprene was added to the polymerization reactor for end-capping, and the reaction was continued for 30min until no free monomers were present. The solution was then wet-coagulated and dried to obtain the functional polymer composite damping brominated grafting agent (Mn = 60000, Mw / Mn = 1.91, bromine content = 6.01%). The functional polymer composite damping brominated grafting agent obtained in this embodiment, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is butyl (C4H9); n and m are the number of repeating units: n≥1, m≥1.

[0067] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: First, in a 4L stainless steel reactor with a jacket, nitrogen gas was purged four times. Then, 300g of dichloromethane, 700g of cyclohexane, and 25g of functional polymer composite damping brominated grafting agent were added to the polymerization reactor and stirred for 60min until completely dissolved. Then, when the temperature was lowered to -80℃, 1000g of monochloromethane, 500g of isobutylene, and 30g of isoprene were added sequentially and stirred until the temperature of the polymerization system dropped to -90℃. Then, 100g of monochloromethane, 1.86g of sesquiethylaluminum chloride, and 0.098g of HCl were mixed and aged at -100℃ for 50min, and then added to the polymerization system and stirred for 5.0hr. Finally, 25g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain the wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0068] Comparative Example 1

[0069] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0070] Preparation of macromolecular composite functional brominating agent: Other conditions are the same as in Example 1, except that methyl isocyanate methacrylate is not added during the preparation of the macromolecular composite functional brominating agent. Instead, methyl methacrylate is added in an amount of 200g. Specifically: First, in a 15L stainless steel reactor with a jacket, argon gas is purged three times. Then, 2000g of cyclohexane, 1000g of 3,5-dibromostyrene, and 4.0g of THF are added sequentially to the polymerization reactor. After heating to 70°C, 5.9 mmol of n-butyllithium is added to initiate the reaction for 80 min. Subsequently, 200g of methyl methacrylate and 3.0g of THF are added to the polymerization reactor, and the reaction is continued for 50 min. Then, 100g of methacrylic acid and 2.0g of THF are added to the polymerization reactor, and the reaction is continued for 30 min. Finally, 10g of methyl methacrylate is added to the polymerization reactor. 1,3-Butadiene was capped and reacted for 20 minutes until no free monomers were present. After the reaction was completed, the product was washed and dried to obtain macromolecular composite functional bromide-1.

[0071] Preparation of functional polymer composite damping brominated grafting agent: Other conditions are the same as in Example 1, except that: No macromolecular composite functional brominated agent is added during the preparation of the functional polymer composite damping brominated grafting agent; instead, macromolecular composite functional brominated agent-1 is added in an amount of 200g. Specifically: First, in a 15L stainless steel reactor with a jacket, argon gas is purged three times. Then, 2000g of cyclohexane, 800g of p-methylstyrene, and 6.0g of THF are added sequentially to the polymerization reactor. After heating to 70℃, 26.1 mmol of n-butyllithium is added to initiate the reaction for 90min. Next, 200g of macromolecular composite functional brominated agent-1 and 2.0g of [other ingredients] are added to the polymerization reactor. THF was heated to 80℃ and reacted for 60 min. Finally, 20 g of isoprene was added to the polymerization reactor for end-capping, and the reaction was continued for 20 min until no free monomers were present. The gel was then wet-coagulated and dried to obtain functional polymer composite damping brominated grafting agent-1. In the functional polymer composite damping brominated grafting agent obtained in this comparative example, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0072] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: Other conditions are the same as in Example 1, except that: no functional polymer composite damping brominated grafting agent is added during the preparation of wide-temperature-range, high-damping brominated branched butyl rubber. Instead, functional polymer composite damping brominated grafting agent-1 is added, with an addition amount of 15g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged three times. Then, 350g of dichloromethane, 150g of cyclohexane, and 15g of functional polymer composite damping brominated grafting agent-1 are added to the polymerization reactor and stirred for 50min until completely dissolved. Then, when the temperature is lowered to -70℃, 500g of monochloromethane, 500g of isobutylene, and 20g of isoprene are added sequentially and stirred until the polymerization system temperature drops to -80℃. Then, 50g of monochloromethane, 1.09g of sesquiethylaluminum chloride, and HCl are added. 0.013g of the mixture was aged at -90℃ for 40 minutes and then added to the polymerization system. After stirring for 4.0 hours, 15g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain a wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0073] Comparative Example 2

[0074] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0075] Preparation of macromolecular composite functional brominator: Other conditions are the same as in Example 2, except that 3,5-dibromostyrene is not added during the preparation of the macromolecular composite functional brominator; instead, 1000g of 3-bromostyrene is added. Specifically: First, in a 15L stainless steel reactor with a jacket, argon gas is purged three times. Then, 2300g of cyclohexane, 1000g of 3-bromostyrene, and 4.5g of THF are added sequentially to the polymerization reactor. After heating to 72°C, 6.3 mmol of n-butyllithium is added to initiate the reaction for 83 min. Next, 230g of isocyanate methacrylate and 3.3g of THF are added to the polymerization reactor, and the reaction is continued for 53 min. Then, 130g of methacrylic acid and 2.4g of THF are added to the polymerization reactor, and the reaction is continued for 33 min. Finally, 15g of... 1,3-Butadiene was capped, and the reaction was carried out for 23 minutes until no free monomers were present. After the reaction was completed, the product was washed and dried to obtain macromolecular composite functional bromide-2.

[0076] Preparation of functional polymer composite damping brominated grafting agent: Other conditions are the same as in Example 2, except that: Instead of adding a macromolecular composite functional brominated agent, macromolecular composite functional brominated agent-2 is added in the preparation process of the functional polymer composite damping brominated grafting agent. The amount added is 230g. That is: First, in a 15L stainless steel reactor with a jacket, argon gas is purged three times. Then, 2300g of cyclohexane, 770g of p-methylstyrene, and 5.5g of THF are added sequentially to the polymerization reactor. After heating to 73°C, 26.7 mmol of n-butyllithium is added to start the reaction for 95 min. Next, 230g of macromolecular composite functional brominated agent-2 and 2.5g of [other ingredients] are added to the polymerization reactor. THF was heated to 83℃ and reacted for 63 min. Finally, 22 g of isoprene was added to the polymerization reactor for end-capping, and the reaction was continued for 23 min until no free monomers were present. The gel was then wet-coagulated and dried to obtain the functional polymer composite damping brominated grafting agent-2. In the functional polymer composite damping brominated grafting agent obtained in this comparative example, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0077] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: Other conditions are the same as in Example 2, except that: no functional polymer composite damping brominated grafting agent is added during the preparation of wide-temperature-range, high-damping brominated branched butyl rubber. Instead, functional polymer composite damping brominated grafting agent-2 is added, with an addition amount of 18g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged three times, and 290g of dichloromethane, 210g of cyclohexane, and 18g of functional polymer composite damping brominated grafting agent-2 are added to the polymerization reactor. The mixture is stirred and dissolved for 53min until completely dissolved. Then, when the temperature is lowered to -73℃, 600g of monochloromethane, 500g of isobutylene, and 22g of isoprene are added sequentially. The mixture is stirred and mixed until the temperature of the polymerization system drops to -83℃. Then, 60g of monochloromethane, 1.21g of sesquiethylaluminum chloride, and HCl are added. 0.035g of the mixture was aged at -92℃ for 43 minutes and then added to the polymerization system. After stirring for 4.3 hours, 18g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain a wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0078] Comparative Example 3

[0079] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0080] Preparation of macromolecular composite functional brominizing agent: Other conditions are the same as in Example 3, except that methacrylic acid is not added during the preparation of macromolecular composite functional brominizing agent. Specifically: First, in a 15L stainless steel reactor with a jacket, argon gas is purged four times. Then, 2500g of cyclohexane, 1000g of 3,5-dibromostyrene, and 5.0g of THF are added to the polymerization reactor in sequence. After heating to 75°C, 7.1 mmol of n-butyllithium is added to start the reaction for 85 min. Then, 250g of isocyanate methacrylate and 3.5g of THF are added to the polymerization reactor, and the reaction is carried out for 56 min. Finally, 20g of 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction is carried out for 26 min until no free monomers are present. After the reaction is completed, the product is washed and dried to obtain macromolecular composite functional brominizing agent-3.

[0081] Preparation of functional polymer composite damping brominated grafting agent: Other conditions are the same as in Example 3, except that: Instead of adding a macromolecular composite functional brominated agent, 260g of macromolecular composite functional brominated agent-3 is added during the preparation of the functional polymer composite damping brominated grafting agent. Specifically: First, in a 15L stainless steel reactor with a jacket, argon gas is purged four times. Then, 2500g of cyclohexane, 750g of p-methylstyrene, and 5.0g of THF are added sequentially to the polymerization reactor. After heating to 75°C, 27.8mmol of n-butyllithium is added to initiate the reaction for 100min. Next, 260g of macromolecular composite functional brominated agent-3 and 3.0g of [other ingredients] are added to the polymerization reactor. THF was heated to 86℃ and reacted for 65 min. Finally, 25 g of isoprene was added to the polymerization reactor for end-capping, and the reaction was continued for 26 min until no free monomers were present. The gel was then wet-coagulated and dried to obtain the functional polymer composite damping brominated grafting agent-3. In the functional polymer composite damping brominated grafting agent obtained in this comparative example, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0082] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: Other conditions are the same as in Example 3, except that: no functional polymer composite damping brominated grafting agent is added during the preparation of wide-temperature-range, high-damping brominated branched butyl rubber. Instead, functional polymer composite damping brominated grafting agent-3 is added, with an addition amount of 21g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged three times, and 700g of dichloromethane, 300g of cyclohexane, and 21g of functional polymer composite damping brominated grafting agent-3 are added to the polymerization reactor. The mixture is stirred and dissolved for 55min until it is completely dissolved. Then, when the temperature is lowered to -75℃, 700g of monochloromethane, 500g of isobutylene, and 25g of isoprene are added in sequence. The mixture is stirred and mixed until the temperature of the polymerization system drops to -85℃. Then, 80g of monochloromethane, 1.41g of sesquiethylaluminum chloride, and HCl are added. 0.055g of the mixture was aged at -95℃ for 45 minutes, then added to the polymerization system and stirred for 4.6 hours. Finally, 20g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain a wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0083] Comparative Example 4

[0084] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0085] Preparation of macromolecular composite functional brominator: Other conditions are the same as in Example 4, except that anionic polymerization is not used in the preparation of the macromolecular composite functional brominator, but free radical polymerization is used instead. Instead of adding n-butyllithium as the initiator, dicumyl peroxide (DCP) is added in an amount of 8.2 mmol. Specifically: First, in a 15L stainless steel reactor with a jacket, argon gas is purged four times. Then, 2700g of cyclohexane, 1000g of 3,5-dibromostyrene, and 5.6g of THF are added sequentially to the polymerization reactor. After heating to 77°C, 8.2 mmol of DCP is added to initiate the reaction for 87 min. Next, 280g of isocyanate methacrylate and 3.7g of THF are added to the polymerization reactor, and the reaction is continued for 58 min. Then, 180g of methacrylic acid and 2.8g of THF are added to the polymerization reactor, and the reaction is continued for 37 min. Finally, 26g of 1,3-butadiene is added to the polymerization reactor for end-capping, and the reaction is continued for 28 min. The reaction continues until no free monomers are present. After the reaction is complete, the product is washed and dried to obtain macromolecular complex functional bromide-4.

[0086] Preparation of functional polymer composite damping brominated grafting agent: Other conditions are the same as in Example 4, except that: no macromolecular composite functional brominated agent is added during the preparation of the functional polymer composite damping brominated grafting agent. Instead, macromolecular composite functional brominated agent-4 is added in an amount of 260g. Specifically: first, in a 15L stainless steel reactor with a jacket, argon gas is purged four times. Then, 2700g of cyclohexane, 730g of p-methylstyrene, and 4.4g of THF are added to the polymerization reactor in sequence. After heating to 77°C, 28.3 mmol of n-butyllithium is added to start the reaction for 106 min. Next, 280g of macromolecular composite functional brominated agent and 3.5g of THF are added to the polymerization reactor. The temperature is raised to 88°C and the reaction is carried out for 67 min. Finally, 28g of isoprene is added to the polymerization reactor for end-capping. The reaction is carried out for 28 min until no free monomers are present. The solution is then wet-coagulated and dried to obtain functional polymer composite damping brominated grafting agent-4. The functional polymer composite damping brominated grafting agent obtained in this comparative example, in the general formula I, I is a small molecule isoprene segment; B is a small molecule 1,3-butadiene segment; R is methyl (CH3); n and m are the number of repeating units: n≥1, m≥1.

[0087] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: Other conditions are the same as in Example 4, except that: no functional polymer composite damping brominated grafting agent is added during the preparation of wide-temperature-range, high-damping brominated branched butyl rubber. Instead, functional polymer composite damping brominated grafting agent-4 is added, with an addition amount of 23g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged three times. Then, 500g of dichloromethane, 500g of cyclohexane, and 23g of functional polymer composite damping brominated grafting agent-4 are added to the polymerization reactor and stirred to dissolve for 57min until completely dissolved. Then, when the temperature is lowered to -78℃, 900g of monochloromethane, 500g of isobutylene, and 28g of isoprene are added sequentially and stirred until the polymerization system temperature drops to -87℃. Then, 90g of monochloromethane, 1.64g of sesquiethylaluminum chloride, and HCl are added. 0.073g of the mixture was aged at -97℃ for 48 minutes and then added to the polymerization system. After stirring for 4.8 hours, 23g of ethanol was added, and the mixture was discharged, coagulated, washed, and dried to obtain a wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

[0088] Comparative Example 5

[0089] (1) Preparation of functional polymer composite damping brominated grafting agent:

[0090] Preparation of macromolecular complex functional brominating agent: Same as in Example 5.

[0091] b. Preparation of functional polymer composite damping brominated grafting agent: Same as in Example 5.

[0092] (2) Preparation of wide-temperature-range, high-damping brominated branched butyl rubber: Other conditions are the same as in Example 5, except that the amount of functional polymer composite damping brominated grafting agent added during the preparation of wide-temperature-range, high-damping brominated branched butyl rubber is 10g. That is: first, in a 4L stainless steel reactor with a jacket, nitrogen gas is purged four times, and 300g of dichloromethane, 700g of cyclohexane, and 10g of functional polymer composite damping brominated grafting agent are added to the polymerization reactor and stirred for 60min until completely dissolved; then, when the temperature is lowered to -80℃, 1000g of monochloromethane, 500g of isobutylene, and 30g of isoprene are added sequentially and stirred until the polymerization system temperature drops to -90℃. Then, 100g of monochloromethane, 1.86g of sesquiethylaluminum chloride, and 0.098g of HCl are mixed and aged at -100℃ for 50min, and then added together to the polymerization system and stirred for 5.0hr. Finally, 25g of ethanol was added, the material was discharged and coagulated, washed, and dried to obtain a wide-temperature-range, high-damping brominated branched butyl rubber product. Sampling and analysis: Standards were prepared, and the test performance is shown in Table 1.

[0093] Table 1 Properties of wide-temperature-range, high-damping brominated branched butyl rubber

[0094]

Claims

1. A method for preparing brominated branched butyl rubber, characterized in that, include: Based on 100% by mass of the reactant monomer 3,5-dibromostyrene, 200%–300% solvent, 100% 3,5-dibromostyrene, and 0.4%–0.6% structure modifier were added sequentially to the polymerization reactor. After heating to 70–80°C, an initiator was added and the reaction was allowed to proceed for 80–90 min. Subsequently, 20%–30% isocyanate alkyl methacrylate and 0.3%–0.4% structure modifier were added to the polymerization reactor, and the reaction was allowed to proceed for 50–60 min. Then, 10%–20% unsaturated carboxylic acid and 0.2%–0.3% structure modifier were added to the polymerization reactor, and the reaction was allowed to proceed for 30–40 min. Finally, 1.0%–3.0% 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was allowed to proceed for 20–30 min until no free monomer remained. After the reaction was completed, the product was washed and dried to obtain a macromolecular composite functional brominating agent. Based on 100% of the total mass of the macromolecular composite functional brominating agent and p-alkylstyrene, 200%~300% solvent, 70%~80% p-alkylstyrene, and 0.4%~0.6% structure modifier are added sequentially to the polymerization reactor. After heating to 70~80℃, an initiator is added and the reaction is allowed to proceed for 90~110 min. Next, 20%~30% of the macromolecular composite functional brominating agent and 0.2%~0.4% of the structure modifier are added to the polymerization reactor, and the temperature is raised to 80~90℃, with the reaction proceeding for 60~70 min. Finally, 2.0%~3.0% isoprene is added to the polymerization reactor for end-capping, and the reaction is allowed to proceed for 20~30 min until no free monomers are present. The resulting solution is then wet-coagulated and dried to obtain a functional polymer composite damping brominated grafting agent. The initiator is RLi, wherein R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a complex group of the above groups containing 1 to 20 carbon atoms; Add 100% to 200% of a mixed solvent (70% to 30% by mass of isobutylene) and 3% to 5% of a functional polymer composite damping brominated grafting agent to the polymerization reactor. Stir and dissolve for 50 to 60 minutes until the grafting agent is completely dissolved. Then, cool to -80 to -70°C, and add 100% to 200% of the diluent, 100% of isobutylene, and 4% to 6% of isoprene sequentially. Stir and mix until the polymerization system temperature drops to -90 to -80°C. Then, mix and age 10% to 20% of the diluent and 0.2% to 0.4% of the co-initiator at -100 to -90°C for 40 to 50 minutes, and then add them to the polymerization system. Stir and react for 4.0 to 5.0 hours. Finally, add 3% to 5% of the diluent and 0.2% to 6% of the isoprene. After adding 5% terminator, the material is discharged, coagulated, washed, and dried to obtain brominated branched butyl rubber.

2. The method according to claim 1, characterized in that, The diluent is a haloalkane, wherein the halogen atom in the haloalkane is chlorine, bromine or fluorine; and the number of carbon atoms in the haloalkane is C1-C4.

3. The method according to claim 2, characterized in that, The haloalkanes are selected from one of the following: chloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, fluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane.

4. The method according to claim 3, characterized in that, The haloalkane is chloromethane.

5. The method according to claim 1, characterized in that, The co-initiator is composed of alkyl aluminum halide and protic acid.

6. The method according to claim 5, characterized in that, 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.

7. The method according to claim 6, characterized in that, The alkyl aluminum halide is sesquiethyl aluminum chloride, and the protic acid is HCl.

8. The method according to claim 5, characterized in that, The total amount of co-initiator added is 0.1% to 0.5% of the mass of the reactant monomer isobutylene, and the molar ratio of protic acid to alkyl aluminum halide is 0.01:1 to 0.1:

1.

9. The method according to claim 1, characterized in that, The solvent is selected from one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene, and ethylbenzene.

10. The method according to claim 9, characterized in that, The solvent is cyclohexane.

11. The method according to claim 1, characterized in that, The terminator is selected from one or more of methanol, ethanol, and butanol.

12. The method according to claim 1, characterized in that, The initiator is selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium, and dodecyllithium.

13. The method of claim 12, characterized in that, The initiator is n-butyllithium.

14. The method according to claim 1, characterized in that, The structure modifier is selected from one of diethylene glycol dimethyl ether, tetrahydrofuran, diethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether, and triethylamine.

15. The method of claim 14, characterized in that, The structure modifier is tetrahydrofuran.

16. The method according to claim 1, characterized in that, The isocyanoalkyl methacrylate is one of methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, and isobutyl isocyanate.

17. The method of claim 16, characterized in that, The isocyanate alkyl methacrylate is methyl isocyanate methacrylate.

18. The method according to claim 1, characterized in that, The unsaturated carboxylic acid mentioned is one of acrylic acid, methacrylic acid, and maleic anhydride.

19. The method of claim 18, characterized in that, The unsaturated carboxylic acid mentioned is methacrylic acid.

20. The method according to claim 1, characterized in that, The p-alkylstyrene is one of p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-n-butylstyrene, and p-isobutylstyrene.

21. The method of claim 20, characterized in that, The p-alkylstyrene mentioned is p-methylstyrene.

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