WO2024066787A1 - Halogenated grafting agent and halogenated branched butyl rubber, preparation method therefor, and use thereof - Google Patents

Abstract

The present invention relates to the field of rubber damping materials, and disclosed are a halogenated grafting agent and a halogenated branched butyl rubber, a preparation method therefor, and use thereof. The halogenated grafting agent comprises a structural unit A, an optional structural unit B, a structural unit C, and a structural unit D, wherein the structural unit A has a structure represented by formula (1); the structural unit C has a structure represented by formula (2); the structural unit B is connected to the structural unit A and the structural unit C, respectively; the structural unit D is a terminal end-capped structural unit; the structural unit B and the structural unit D are each independently from a conjugated diene. The method of the present invention solves the problems of low damping performance and heterogeneous rearrangement of a halogenated structure in the butyl rubber, the mechanical property and the air permeability of the butyl rubber are prevented from being damaged by the damping brominated grafting agent, and the damping performance and the tensile strength of the butyl rubber are also improved.

Description

Halogenated grafting agent and halogenated branched butyl rubber and preparation method and application thereof

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Chinese patent application 202211183875.0 filed on September 27, 2022, the contents of which are incorporated herein by reference.

Technical Field

The invention relates to the field of rubber damping materials, and in particular to a halogenated grafting agent and a halogenated branched butyl rubber, and a preparation method and application thereof.

Background technique

Due to the unique viscoelasticity of polymers, rubber damping materials have obvious damping effects in reducing vibration and noise, and improving the working environment of humans and machines. They have been widely used in many fields such as high-speed rail, aerospace, naval ships, mechanical engineering, automobiles, and electronic appliances. In particular, the vibration and noise of the cabinet caused by the rotation of the fan in the data storage system of various IT equipment such as servers, computers, workstations, switches, etc. seriously affect the service life of the hard disk. The demand for high-efficiency damping and vibration reduction products is very urgent. In addition, as the application environment of electronic equipment faces a complex use environment with lower temperatures and higher temperatures, extremely high requirements are placed on rubber damping materials.

Diolefin rubber is widely used in various fields of daily production and life. Its main industrial products include butadiene rubber, isoprene rubber, butyl rubber, halogenated butyl rubber, etc. Bromobutyl rubber is an important type of halogenated butyl rubber. Bromobutyl rubber (BIIR) has excellent damping performance and is one of the most widely used basic damping rubbers. However, brominated butyl rubber currently still has defects such as insufficient damping value, unstable damping performance, insufficient effective damping temperature range, and poor mechanical properties. It cannot meet the requirements of large-scale equipment and precision instruments for material damping performance, thus becoming a bottleneck for the expansion of brominated butyl rubber materials.

CN103113682A discloses a high-performance damping rubber and a preparation method thereof. The high-performance damping rubber is obtained by blending and polymerizing a first precursor and a second precursor, wherein the first precursor has a molecular chain with a cationic group, and the second precursor has a molecular chain with an anionic group, and the molar ratio of the cationic group to the anionic group in the rubber is 1:1. The obtained high-performance damping rubber has a breaking strength of 5-20MPa, an elongation at break of 200%-300%, a repair efficiency of up to 90%, a repair temperature of 20-100°C, a wide damping temperature range and high repair efficiency.

CN103113682A discloses a wide temperature range high damping material for electronic products and a preparation method thereof. A supramolecular network structure is formed through the interaction between non-polar butyl rubber, brominated tert-octylphenol formaldehyde resin and polar small molecule hindered phenol A060, and the temperature range can reach -60 to 100°C.

Liao Mingyi et al. (Journal of Dalian Maritime University, 2008, 34(2):83-86) disclosed a step-by-step method for improving the damping performance of butyl rubber (IIR), using IIR as the polymer network I, poly(styrene-methyl The butyl rubber/poly(styrene-methyl methacrylate) [P(St-MMA)] was used as the polymer network II, and the butyl rubber/poly(styrene-methyl methacrylate) interpenetrating polymer network [IIR/P(St-MMA)] was prepared by graft polymerization to prepare a butyl rubber material with a wide temperature range and high damping.

Although the existing technology can broaden the effective damping temperature range of rubber and improve the damping performance of rubber to a certain extent by using blending, copolymerization and interpenetrating network polymer methods, these methods still have certain limitations, which will lead to a decrease in the mechanical properties of the modified materials.

Summary of the invention

The purpose of the present invention is to overcome the problem of low damping performance and mechanical properties of rubber materials in the prior art, and to provide a halogenated grafting agent and a halogenated branched butyl rubber and a preparation method and application thereof. The halogenated grafting agent can be used to prepare the halogenated branched butyl rubber to obtain the halogenated branched butyl rubber with a higher maximum damping factor. The method of the present invention solves the problems of low damping and halogenated structural isomer rearrangement in butyl rubber, not only avoiding the damage of the damping brominated grafting agent to the mechanical properties and air permeability of butyl rubber, but also improving the damping performance and tensile strength of butyl rubber.

In order to achieve the above-mentioned object, the first aspect of the present invention provides a halogenated grafting agent, which comprises a structural unit A, an optional structural unit B, a structural unit C and a structural unit D; wherein the structural unit A has a structure shown in formula (1); the structural unit C has a structure shown in formula (2); the structural unit B is connected to the structural unit A and the structural unit C respectively; the structural unit D is a terminal capping structural unit; the structural unit B and the structural unit D are each independently derived from a conjugated diene;

Wherein, _R1 and _R2 are each independently hydrogen or a _C1 - _C5 straight chain or branched alkyl group; _R3 is a _C1 - _C8 straight chain or branched alkyl group; _R4 and _R5 are each independently hydrogen or a _C1 - _C4 straight chain or branched alkyl group; and X is a halogen.

The second aspect of the present invention provides a method for preparing a halogenated grafting agent, the preparation method comprising:

S1. Under polymerization reaction conditions and in the presence of an initiator, polymerizing the monomer represented by formula (I) and the monomer represented by formula (II) to obtain a polymerization product;

Alternatively, (1) subjecting the monomer represented by formula (I) to a first polymerization reaction in the presence of a molecular weight regulator, a first solvent and a first initiator, and optionally adding a second conjugated diene to a first end-capping reaction to obtain a first product;

(2) subjecting the monomer represented by formula (II) to a second polymerization reaction in the presence of a structure regulator, a second solvent, and a second initiator to obtain a second product, and then adding the first product to conduct a third polymerization reaction to obtain a third product;

S2, subjecting the polymer product obtained in step S1 or the third product obtained in step (2) to a second end-capping reaction with the first conjugated diene to obtain the halogenated grafting agent;

Wherein, _R1 and _R2 are each independently hydrogen or a _C1 -C5 straight chain or branched alkyl group; _R3 is a _C1 - _C8 straight chain or branched alkyl group; _R4 and _R5 are each independently hydrogen or a _C1 - _C4 straight chain or branched alkyl group; and X is a halogen.

The third aspect of the present invention provides a halogenated grafting agent obtained by the aforementioned preparation method.

The fourth aspect of the present invention provides the use of the aforementioned halogenated grafting agent as a grafting agent in the preparation of diene rubber.

The fifth aspect of the present invention provides a halogenated branched butyl rubber, which comprises: a structural unit E derived from isobutylene, a structural unit F derived from isoprene and a structural unit G derived from a halogenated grafting agent; wherein the halogenated grafting agent is the aforementioned halogenated grafting agent.

A sixth aspect of the present invention provides a method for preparing a halogenated branched butyl rubber, the method comprising the following steps:

In the presence of a diluent, an organic solvent and a co-initiator, isobutylene, isoprene and the aforementioned halogenated grafting agent are subjected to cationic polymerization to obtain the halogenated branched butyl rubber.

The seventh aspect of the present invention provides a halogenated branched butyl rubber obtained by the aforementioned preparation method.

The eighth aspect of the present invention provides the use of the aforementioned halogenated branched butyl rubber in automobiles and electronic appliances.

Through the above technical solution, the beneficial technical effects achieved by the present invention are as follows:

(1) The halogenated grafting agent provided by the present invention combines a p-alkylphenyl structural unit and a halogenated alkyl structural unit on a macromolecular chain, and the molecular chain has the characteristics of high rigidity, large steric hindrance, strong adsorption force and multiple active points, so that the p-alkylphenyl and the halogen atoms produce a significant "synergistic effect" in improving the damping property of the material. When the halogenated grafting agent is used as a halogenated grafting agent for preparing halogenated branched butyl rubber, the damping property of the halogenated branched butyl rubber can be greatly improved, and a high-damping halogenated branched butyl rubber with a high maximum damping factor can be prepared.

(2) The halogenated grafting agent prepared by free radical polymerization and anionic polymerization of the present invention contains non-polar The alkylbenzene ring structure has the characteristics of high rigidity and large steric hindrance, which not only avoids the problem of widening of molecular weight distribution of butyl rubber due to branching, thereby leading to a decrease in the mechanical properties and air tightness of butyl rubber, but also improves the tensile strength of butyl rubber.

(3) The halogenated branched butyl rubber prepared by the present invention is produced by addition polymerization using a high molecular weight damping halogenated grafting agent rather than by ion substitution. The para-alkylphenyl and secondary bromine halogen structures in the grafting agent are embedded in the main chain segment of the butyl rubber, blocking the conditions for molecular structure isomerization, improving the stability of the damping performance of the halogenated branched butyl rubber, and broadening the application range of the high damping halogenated branched butyl rubber.

(4) In the preparation process of the high-damping halogenated branched butyl rubber of the present invention, no volatile organic compounds (VOC) and by-product HBr are emitted, which reduces the harm to humans and the environment and eliminates the alkali washing and recovery process of the by-product HBr. The preparation method is green and environmentally friendly, has a short process flow, low production cost, and is suitable for industrial production.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an infrared spectrum of the halogenated grafting agent obtained in Preparation Example 1.

Detailed ways

The endpoints and any values of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article.

The first aspect of the present invention provides a halogenated grafting agent, which comprises a structural unit A, an optional structural unit B, a structural unit C and a structural unit D; wherein the structural unit A has a structure shown in formula (1); the structural unit C has a structure shown in formula (2); the structural unit B is connected to the structural unit A and the structural unit C respectively; the structural unit D is a terminal capping structural unit; the structural unit B and the structural unit D are independently derived from a conjugated diene;

wherein _R1 and _R2 are each independently hydrogen or a _C1 - _C5 straight chain or branched alkyl group; _R3 is a _C1 - _C8 straight chain or branched alkyl group; _R4 and _R5 are each independently hydrogen or a _C1 - _C4 straight chain or branched alkyl group; X is a halogen white.

The halogenated grafting agent of the present invention combines a para-alkylphenyl structural unit and a halogenated alkyl structural unit on a macromolecular chain, and the molecular chain has the characteristics of high rigidity, high steric hindrance, strong adsorption force and multiple active points, and the end of the copolymer contains a conjugated diene structural unit, so that the multi-component copolymer has high polymerization activity and can be used as a grafting agent for preparing branched diene rubber, in particular, for preparing halogenated branched diene rubber.

The grafting agent of the present invention contains a large number of benzene ring structures in a regular arrangement, so that the characteristics of high rigidity and large steric hindrance can be fully utilized, and the modulus and barrier properties of the halogenated grafting agent can be greatly improved, so that the halogenated branched diene rubber prepared therefrom has high damping performance while maintaining its excellent mechanical strength and air tightness.

The stability of the bromine structure in the grafting agent of the present invention not only improves the high damping performance of the halogenated branched diene rubber, but also helps to solve the problem of butyl rubber having few double bonds and being difficult to vulcanize due to its high saturation, helps to increase its vulcanization speed, and can improve the vulcanization processability of the halogenated branched diene rubber.

Therefore, the grafting agent of the present invention contains a large number of benzene ring structures, stable halogen structures and high isotacticity. The halogenated branched diene rubber prepared by the grafting agent has high damping performance while also having excellent air tightness, mechanical strength and vulcanization processability to meet various application requirements.

In the present invention, examples of the _C1 - _C8 straight or branched alkyl group may be any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, isoheptyl, 2-methylhexyl, 2-ethylhexyl, 1-methylheptyl, 2-methylheptyl, n-octyl and isooctyl.

In some embodiments, R ₁ and R ₂ are each independently hydrogen or a C ₁ -C ₃ straight or branched alkyl group, preferably hydrogen, methyl, ethyl or propyl.

In some embodiments, R ₃ is a C ₁ -C ₅ straight or branched alkyl group; preferably a methyl group, an ethyl group, a n-propyl group or an isopropyl group.

In some embodiments, R ₄ and R ₅ are each independently hydrogen or C ₁ -C ₂ alkyl; preferably hydrogen, methyl or ethyl.

In some embodiments, X is selected from at least one of Cl and Br, preferably Br.

In some embodiments, the conjugated diene is butadiene and/or isoprene.

In some preferred embodiments of the present invention, the structural unit represented by formula (1) may be a structural unit derived from p-alkylstyrene, such as p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-n-butylstyrene, p-isobutylstyrene or p-isopentylstyrene.

In some preferred embodiments of the present invention, the structural unit represented by formula (2) can be a structural unit derived from a halogenated olefin, such as vinyl bromide, vinyl chloride, 1-bromo-1-propylene, 2-bromo-1-propylene, 1-bromo-1-butene or 2-bromo-1-butene, preferably a structural unit derived from vinyl bromide or 2-bromo-1-butene.

In order to improve the maximum damping factor, air permeability and tensile strength of the halogenated branched butyl rubber, in some embodiments, the mass ratio of the structural unit A, the structural unit B, the structural unit C and the structural unit D is 100:0-2:15-70:3-7, for example, 100:0.3:30:4, 100:0.5:40:5, 100:0.6:50:6, 100:0.8:60:7, 100:0.9:70:5, 100:1:65:4, 100:1.2:50:5, 100:1.3:55:6, 100:1.4:45:3, 100:1.5:80:5, 100:1.8:78:5, and any value within the range composed of any two of the above values, preferably 100:0.3-1.5:30-68:4-6. When the mass ratio of each structural unit satisfies the range, the maximum damping factor tanδ _max ≥1.5, the air permeability is 20.215-21.251 cm ³ , and the tensile strength is 17.6 MPa-20.6 MPa of the obtained halogenated branched butyl rubber.

In the present invention, the mass ratio of each structural unit can be expressed by the feed mass ratio of the monomers corresponding to each structural unit.

In some embodiments, the structural unit B is derived from butadiene; and the structural unit D is derived from isoprene.

As a preferred embodiment, the structure of the halogenated grafting agent of the present invention is shown in the general formula I1-A1-B1-C-B2-A2-I2, wherein I1 and I2 are structural units derived from isoprene; A1 and A2 are structural units shown in formula (1); B1 and B2 are structural units derived from butadiene; and C is a structural unit shown in formula (2).

In some embodiments, the mass percentage of halogen in the halogenated grafting agent is 3-7 wt %, preferably 4-6 wt %.

In the present invention, the halogen content is determined by using a Q600 TG/DTG thermogravimetric analyzer.

In some embodiments, the number average molecular weight of the halogenated grafting agent is 25,000-50,000 g/mol, preferably 30,000-40,000 g/mol.

In some embodiments, the molecular weight distribution index (Mw/Mn) of the halogenated grafting agent is 1.5-4, such as 1.6, 1.9, 2, 2.5, 2.8, 3, 3.5, 3.7, and any value within the range of any two of the above values, preferably 2-3.5.

In some embodiments, the halogenated grafting agent is a block copolymer or a random copolymer.

In some embodiments, the apparent viscosity of the halogenated grafting agent at 25° C. is 5-35 mPa·s.

In the present invention, the apparent viscosity of the halogenated grafting agent is tested using an Ubbelohde viscometer according to the viscosity measurement method of GB/T 10247-2008.

The second aspect of the present invention provides a method for preparing a halogenated grafting agent, the preparation method comprising:

S1. Under polymerization reaction conditions and in the presence of an initiator, polymerizing the monomer represented by formula (I) and the monomer represented by formula (II) to obtain a polymerization product;

Alternatively, (1) subjecting the monomer represented by formula (I) to a first polymerization reaction in the presence of a molecular weight regulator, a first solvent and a first initiator, and optionally adding a second conjugated diene to a first end-capping reaction to obtain a first product;

(2) subjecting the monomer represented by formula (II) to a second polymerization reaction in the presence of a structure regulator, a second solvent, and a second initiator to obtain a second product, and then adding the first product to conduct a third polymerization reaction to obtain a third product;

S2, subjecting the polymer product obtained in step S1 or the third product obtained in step (2) to a second end-capping reaction with the first conjugated diene to obtain the halogenated grafting agent;

Wherein, _R1 and _R2 are each independently hydrogen or a _C1 - _C5 straight chain or branched alkyl group; _R3 is a _C1 - _C8 straight chain or branched alkyl group; _R4 and _R5 are each independently hydrogen or a _C1 - _C4 straight chain or branched alkyl group; and X is a halogen.

In some embodiments, R ₁ and R ₂ are each independently hydrogen or a C ₁ -C ₃ straight or branched alkyl group, preferably hydrogen, methyl, ethyl or propyl.

In some embodiments, R ₃ is a C ₁ -C ₅ straight or branched alkyl group; preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl or isopentyl.

In some embodiments, R ₄ and R ₅ are each independently hydrogen or C ₁ -C ₂ alkyl; preferably hydrogen, methyl or ethyl.

In some embodiments, X is selected from at least one of Cl and Br, preferably Br.

The invention first synthesizes a macromolecular halogenating agent with anionic reaction activity; secondly, alkyl lithium is used as an initiator to synthesize a high molecular damping halogenated grafting agent from p-alkyl styrene and the macromolecular halogenating agent; and the high molecular damping halogenated grafting agent, isobutylene and isoprene are subjected to cationic polymerization in a catalytic system of alkyl aluminum halide and protonic acid to prepare a high damping halogenated branched butyl rubber. With the introduction of benzene rings and halogen atoms in the grafting agent of the invention and the use of anionic polymerization method, the benzene rings and halogen atoms are arranged in a regularity, thereby increasing the steric hindrance effect of the molecular chain, enhancing the polarity, resulting in an increase in the movement resistance of the chain segment, an increase in the internal friction, and an increase in the relaxation tension of the chain segment. In this way, in the grafting preparation process of butyl rubber, not only the damage of the damping halogenated grafting agent to the mechanical properties and air permeability of the butyl rubber is avoided, but also the damping performance and tensile strength of the butyl rubber are improved.

The method of the invention can prepare high-damping halogenated branched butyl rubber with a high maximum damping factor, even tanδ _max ≥1.5.

In some embodiments, the monomer represented by formula (I), the second conjugated diene, the monomer represented by formula (II) and the first The mass ratio of the monoconjugated diene is 100:0-2:15-70:3-7, for example, 100:0.3:30:4, 100:0.5:40:5, 100:0.6:50:6, 100:0.8:60:7, 100:0.9:70:5, 100:1:65:4, 100:1.2:50:5, 100:1.3:55:6, 100:1.4:45:3, 100:1.5:80:5, 100:1.8:78:5, and any value within the range of any two of the above values, preferably 100:0.3-1.5:30-68:4-6.

In the present invention, the mass ratio of the monomer represented by formula (I), the second conjugated diene, the monomer represented by formula (II) and the first conjugated diene is controlled within a specific range, which can effectively ensure the normal reaction of the polymer grafting agent and the grafted butyl rubber preparation.

In the present invention, the second conjugated diene and the first conjugated diene are used as end-capping agents, and their dosage has an important influence on the polymerization reaction. Too much dosage will increase the flexibility of the grafting agent chain segment and destroy the damping performance and mechanical strength of the butyl rubber. Too little dosage will lead to incomplete end-capping, fewer reactive sites, and lower grafting rate, which will deteriorate the damping performance and mechanical strength modification effect of the butyl rubber.

In some embodiments, the monomer represented by formula (II) is a halogenated olefin, preferably at least one selected from vinyl bromide, vinyl chloride, 1-bromo-1-propylene, 2-bromo-1-propylene, 1-bromo-1-butene and 2-bromo-1-butene; preferably vinyl bromide or 2-bromo-1-butene.

In some embodiments, the monomer represented by formula (I) is p-alkylstyrene, preferably at least one selected from p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-n-butylstyrene, p-isobutylstyrene and p-isopentylstyrene; preferably p-methylstyrene.

In some embodiments, the second conjugated diene is butadiene and/or isoprene, preferably isoprene.

In some embodiments, the first conjugated diene butadiene and/or isoprene is preferably 1,3-butadiene.

In some embodiments, the first initiator is an organic peroxide, preferably at least one selected from dicumyl peroxide (DCP), cumyl hydroperoxide and benzoyl peroxide (BPO), more preferably benzoyl peroxide (BPO).

In some embodiments, the second initiator is a hydrocarbon monolithium compound R-Li, wherein R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of the above groups containing 1 to 20 carbon atoms, preferably selected from at least one of n-butyl lithium, sec-butyl lithium, methyl butyl lithium, phenyl butyl lithium, naphthalene lithium, cyclohexyl lithium and dodecyl lithium, and more preferably n-butyl lithium.

In some embodiments, the molecular weight regulator is selected from at least one of tert-decyl mercaptan, tert-dodecyl mercaptan, tert-tetradecyl mercaptan and tert-hexadecyl mercaptan, preferably tert-dodecyl mercaptan.

In some embodiments, the structure regulator is a polar organic compound, preferably at least one selected from diethylene glycol dimethyl ether (DGE), tetrahydrofuran (THF), ethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME) and triethylamine, more preferably tetrahydrofuran (THF).

The structure regulator in the present invention is a polar organic compound that generates a solvent in the polymerization system. Chemical effect, structure regulator is used to adjust the ionic reaction activity, can adjust the reactivity ratio of alkyl styrene and isoprene, so that the two can be randomly copolymerized.

In some embodiments, the first solvent and the second solvent are each independently a hydrocarbon solvent, preferably at least one selected from linear alkanes, aromatic hydrocarbons and cycloalkanes, and more preferably at least one selected from pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene.

In the present invention, there is no particular limitation on the amount of the molecular weight regulator, structure regulator, solvent, etc., and they can be added according to conventional amounts in the art.

In some embodiments, the conditions of the first polymerization reaction include: a reaction temperature of 50-60° C. and a reaction time of 4-6 h.

In some embodiments, the conditions of the first end-capping reaction include: a reaction temperature of 50-60° C. and a reaction time of 20-40 min.

In some embodiments, the conditions of the second polymerization reaction include: a reaction temperature of 60-70° C. and a reaction time of 70-90 min.

In some embodiments, the conditions of the third polymerization reaction include: reaction temperature of 80-90° C., and reaction time of 80-100 min.

In some embodiments, the conditions of the second capping reaction include: a reaction temperature of 80-90° C. and a reaction time of 30-40 min.

The method of the present invention further comprises adding a terminator to terminate the reaction after the polymerization is completed. The terminator can be selected from one or more of methanol, ethanol and butanol.

In the present invention, the polymerization reaction is carried out in an oxygen-free and water-free environment, preferably in an inert gas environment. The polymerization and dissolution processes are completed in hydrocarbon solvents.

In the present invention, vinyl bromide and p-methylstyrene can be directly polymerized without adding a capping agent in the middle. Since vinyl bromide cannot undergo anionic polymerization, the polymerization can only be carried out by free radical polymerization, using an organic peroxide such as BPO to initiate the reaction.

The third aspect of the present invention provides a halogenated grafting agent obtained by the aforementioned preparation method.

The fourth aspect of the present invention provides the use of the aforementioned halogenated grafting agent as a grafting agent in the preparation of diene rubber.

The fifth aspect of the present invention provides a halogenated branched butyl rubber, which comprises: a structural unit E derived from isobutylene, a structural unit F derived from isoprene and a structural unit G derived from a halogenated grafting agent; wherein the halogenated grafting agent is the aforementioned halogenated grafting agent.

In some embodiments, based on the total weight of the halogenated branched butyl rubber, the mass ratio of the structural unit E, the structural unit F and the structural unit G is 100:2-6:3-8, preferably 100:3-5:4-7.

A sixth aspect of the present invention provides a method for preparing a halogenated branched butyl rubber, the method comprising the following steps:

In the presence of a diluent, an organic solvent and a co-initiator, isobutylene, isoprene and the aforementioned halogenated grafting agent are subjected to cationic polymerization to obtain the halogenated branched butyl rubber.

In some embodiments, the mass ratio of isobutylene, isoprene and the halogenated grafting agent is 100:2-6:3-8, preferably 100:3-5:4-7.

In some embodiments, the diluent is a halogenated alkane, wherein the halogen atom in the halogenated alkane is F, Cl or Br, and the number of carbon atoms in the halogenated alkane is 1-4; preferably, the diluent is selected from at least one of monochloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, monofluoromethane, difluoromethane, tetrafluoroethane and carbon tetrafluoride.

In some embodiments, the solvent is a hydrocarbon solvent, preferably at least one of linear alkanes, aromatic hydrocarbons and cycloalkanes, and more preferably at least one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene.

In some embodiments, the co-initiator comprises a protonic acid and an alkylaluminum halide; preferably, the molar ratio of the protonic acid to the alkylaluminum halide in the co-initiator is 1:10-100; preferably, the protonic acid is selected from at least one of HCl, HF, HBr, _H2SO4 , _H2CO3 , _H3PO4 and _HNO3 ; the alkylaluminum halide is selected from at least one of _{diethylaluminum} monochloride, _{diisobutylaluminum} monochloride, _{methylaluminum} dichloride, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, n-propylaluminum dichloride, isopropylaluminum dichloride, dimethylaluminum chloride and ethylaluminum chloride.

In some embodiments, the mass ratio of the isobutylene to the co-initiator is 100:0.01-0.5.

In some embodiments, the conditions for the cationic polymerization include: a polymerization temperature of -100°C to -80°C; and a cationic polymerization time of 3-4h.

The seventh aspect of the present invention provides a halogenated branched butyl rubber obtained by the above-mentioned preparation method. The halogenated branched butyl rubber of the present invention is preferably a brominated branched butyl rubber.

The eighth aspect of the present invention provides the application of the aforementioned halogenated branched butyl rubber in various fields such as automobiles and electronic appliances.

According to a preferred embodiment of the present invention, the halogenated grafting agent is a linear block copolymer polymerized from isoprene, 1,3-butadiene, p-alkylstyrene and vinyl bromide.

According to a particularly preferred embodiment of the present invention, the preparation method of the halogenated grafting agent specifically comprises the following steps:

S1. Based on 100 parts of vinyl bromide, first, in a 15L stainless steel reactor with a jacket, inert gas is replaced 2-4 times, and 100-200 parts of solvent, 100 parts of vinyl bromide, and 0.2-0.5 parts of molecular weight regulator are added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reaches 50-60°C, 0.01-0.15 parts of the first initiator are added, and the reaction is carried out for 4-6 hours. Then, 1-4 parts of 1,3-butadiene are added to the polymerization reactor for end-capping, and the reaction is carried out for 20-40 minutes until no free monomer is present. After the reaction is completed, the macromolecular brominating agent is obtained by washing and drying;

S2. Based on 100% of the total mass of the reaction monomers, first, in a 15L stainless steel reactor with a jacket, argon is replaced 2-4 times, and 200%-300% of the solvent, 60%-80% of p-alkylstyrene, and 0.3%-0.5% of the structure regulator are added to the polymerization kettle in sequence. After the temperature is raised to 60-70°C, a second initiator is added and the reaction is carried out for 70-90 minutes; then, 20%-40% of the macromolecular brominating agent and 0.1%-0.2% of the structure regulator are added to the polymerization kettle, the temperature is raised to 80-90°C, and the reaction is carried out for 80-100 minutes; finally, 3-5 parts of isoprene are added to the polymerization kettle for end-capping, and the reaction is carried out for 30-40 minutes until no free monomers are present. The glue solution is subjected to wet coagulation and drying to obtain a halogenated grafting agent.

According to a particularly preferred embodiment of the present invention, the method for preparing halogenated branched butyl rubber from the above-mentioned halogenated grafting agent specifically comprises the following steps:

Based on 100% of the mass of the reaction monomer isobutylene, first, in a 4L stainless steel reactor with a jacket, nitrogen is replaced 3-5 times, 100%-200% of a mixed solvent (diluent/solvent V:V ratio is 70-30/30-70) and 4%-7% of the halogenated grafting agent prepared above are added to the polymerization reactor, and stirred and dissolved for 40-60 minutes until the grafting agent is completely dissolved; then, when the temperature is lowered to -80 to -70°C, 100%-200% of the diluent and solvent are added in sequence. agent, 100% isobutylene, 3%-5% isoprene, stirring and mixing until the temperature of the polymerization system drops to -90 to -80°C, then 10%-20% diluent and 0.01%-0.5% co-initiator are mixed and aged at -100 to -90°C for 40-50 minutes, and then added into the polymerization system together with stirring reaction for 3-4 hours, and finally 4%-7% terminator is added, the discharged material is condensed, washed and dried to obtain a high damping halogenated branched butyl rubber product.

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

In the following examples and comparative examples, if no specific conditions are specified, the experiments are carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if no manufacturer is specified, are conventional products that can be obtained through commercial channels. The mass ratio of each structural unit contained in the obtained multi-polymer product and the halogenated branched butyl rubber is determined according to the raw material feed amount.

(1) Source of raw materials:

1,3-Butadiene: polymerization grade, purchased from PetroChina Lanzhou Petrochemical Company;

Isobutylene and isoprene: polymer grade, purchased from Zhejiang Xinhui New Materials Co., Ltd.;

p-Methylstyrene: polymer grade, purchased from Jiande Langfeng Chemical Co., Ltd.;

p-Butylstyrene: polymerization grade, purchased from Luoyang Boyu Energy Technology Co., Ltd.;

Vinyl bromide: polymer grade, purchased from Wuhan Fuxinyuan Technology Co., Ltd.;

Benzoyl peroxide (BPO): purchased from Lanzhou Additive Factory;

n-Butyl lithium: purity 98%, purchased from Nanjing Tonglian Chemical Co., Ltd.;

Sesquiethylaluminum chloride: purity 98%, purchased from Bailingwei Technology Co., Ltd.;

Other reagents are commercially available products.

(2) Analytical testing methods:

Determination of bromine content: Weigh 10 mg of sample and use Q600 TG/DTG thermogravimetric analyzer to heat The sample was thermally degraded at a rate of 10°C/min in a nitrogen atmosphere with a flow rate of 50mL/min. The first stage of thermal degradation is the debromination of the bromine-containing units of the sample to form HBr, and then the bromine content (X) in the sample is inferred from the percentage of HBr removed. The calculation formula is as follows:

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

Determination of number average molecular weight (Mn) and its distribution index (Mw/Mn): Determination was performed using a 2414 gel permeation chromatograph (GPC) produced by Waters, USA. The polystyrene standard was used as the calibration curve, the mobile phase was tetrahydrofuran, the column temperature was 40°C, the sample concentration was 1 mg/mL, the injection volume was 50 μL, the elution time was 40 min, and the flow rate was 1 mL·min ^-1 .

Determination of apparent viscosity: GB/T 10247-2008 viscosity measurement method is adopted.

Dynamic mechanical analysis (DMA): measured on a 242C dynamic mechanical analyzer from Netzsch, Germany, in tensile mode. The sample size is 10 mm long, 6 mm wide, and 2 mm thick. The temperature range is -90°C to 90°C, the heating rate is 3°C/min, and the data at a frequency of 10 Hz are selected for analysis.

Air tightness determination: The air permeability number was determined using an automated air tightness tester in accordance with ISO 2782:1995. The test gas was N ₂ , the test temperature was 23° C., and the test sample was a circular sea piece with a diameter of 8 cm and a thickness of 1 mm.

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

In the examples and comparative examples of the present invention, the mass ratio of the monomer feed is equal to the mass ratio of the corresponding structural units in the prepared halogenated grafting agent.

Preparation Example 1

(1) Preparation of macromolecular brominating agent: First, in a 15L stainless steel reactor with a jacket, argon gas was replaced twice, and 1000g of cyclohexane, 1000g of vinyl bromide, and 2g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 50°C, 0.1g of BPO was added and reacted for 4h; then 10g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 20min until no free monomer was present. After the reaction was completed, the macromolecular brominating agent was washed and dried to obtain 1010g; wherein, 10g of structural unit B (1,3-butadiene) was contained;

(2) Preparation of halogenated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon was replaced twice, and 2000g of cyclohexane, 600g of p-methylstyrene, and 3g of THF were added to the polymerization kettle in sequence. The temperature was raised to 60°C, and 14.6mmol of n-butyllithium was added to start the reaction for 70min. Then, 400g of macromolecular brominating agent (containing 4g of structural unit B) and 1g of THF were added to the polymerization kettle. The temperature was raised to 80°C and the reaction was carried out for 80min. Finally, 30g of isoprene was added to the polymerization kettle and the end-capping reaction was carried out for 30min until no free monomer was present. The gel was wet-coagulated and dried to obtain a halogenated grafting agent S1, in which the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.67:67:5.

After testing, the halogenated grafting agent S1 had an Mn of 30350, an Mw/Mn of 2, a bromine content of 5.97%, and an apparent viscosity of 8 mPa·s at 25°C.

As can be seen from Figure 1, the asymmetric secondary vibration double absorption peak of the benzene ring appears at wave numbers 3005-3100 cm- ¹ ; the secondary vibration absorption peak of the methyl group ( _CH3 ) appears at wave numbers 2950-2800 cm ^-1 ; the secondary vibration absorption peak of the "carbon-carbon double bond" appears at wave numbers 1680-1500 cm ^-1 ; the secondary vibration single absorption peak of the para-substituted benzene ring appears at wave numbers 900-850 cm ^-1 ; the secondary vibration single absorption peak of the bromine atom appears at wave numbers 700-650 cm ^-1 , indicating that the halogenated grafting agent prepared from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene contains p-methylbenzene structure and bromine substitution structure.

Preparation Example 2

(1) Preparation of macromolecular brominating agent: First, in a 15L stainless steel reactor with a jacket, argon gas was replaced twice, and 1200g of cyclohexane, 1000g of vinyl bromide, and 2.5g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 52°C, 0.4g of BPO was added and reacted for 4.5h; then 15g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 26min until no free monomer was present. After the reaction was completed, the macromolecular brominating agent was obtained by washing and drying;

(2) Preparation of halogenated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon was introduced twice, and 2100g cyclohexane, 650g p-methylstyrene, and 3.5g THF were added to the polymerization kettle in sequence. The temperature was raised to 62°C, and 14.9mmol n-butyl lithium was added to start the reaction for 74min. Then, 350g macromolecular brominating agent and 1.2g THF were added to the polymerization kettle. The temperature was raised to 82°C and the reaction was carried out for 85min. Finally, 35g isoprene was added to the polymerization kettle and the end-capping reaction was carried out for 32min until no free monomers were present. The gel was wet condensed and dried to obtain the halogenated grafting agent S2, in which the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.77:54:5.4.

After testing, the Mn of the halogenated grafting agent S2 was 31500, the Mw/Mn was 2.3, the bromine content was 5.63%, and the apparent viscosity at 25°C was 12 mPa·s.

Preparation Example 3

(1) Preparation of macromolecular brominating agent: First, in a 15L stainless steel reactor with a jacket, argon gas was replaced three times, and 1500g of cyclohexane, 1000g of vinyl bromide, and 3g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 54°C, 0.7g of BPO was added and reacted for 5h; then 20g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 30min until no free monomer was present. After the reaction was completed, the macromolecular brominating agent was obtained by washing and drying;

(2) Preparation of halogenated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon was introduced for replacement three times, and 2300g of cyclohexane, 700g of p-methylstyrene, and 4g of THF were added to the polymerization reactor in sequence, and the temperature was raised to 64°C. 15.5mmol of n-butyl lithium was added to start the reaction for 78min; then 300g of macromolecular brominating agent and 1.4g of THF were added to the polymerization reactor, and the temperature was raised to 85°C and the reaction was carried out for 90min; finally, 40g of isoprene was added to the polymerization reactor and the end-capping reaction was carried out for 34min until no free monomer was present. The gel was The halogenated grafting agent S3 was prepared by wet condensation and drying, wherein the mass ratio of the structural units derived from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.86:43:5.7.

The halogenated grafting agent S3 was tested to have a Mn of 33600, a Mw/Mn of 2.7, a bromine content of 5.03%, and an apparent viscosity of 17 mPa·s at 25°C.

Preparation Example 4

(1) Preparation of macromolecular brominating agent: First, in a 15L stainless steel reactor with a jacket, argon gas was replaced three times, and 1700g of cyclohexane, 1000g of vinyl bromide, and 4g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 56°C, 0.9g of BPO was added and reacted for 5.3h; then 30g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 30min until no free monomer was present. After the reaction was completed, the macromolecular brominating agent was obtained by washing and drying;

(2) Preparation of halogenated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon was introduced for replacement three times, and 2500g cyclohexane, 730g p-methylstyrene, and 4.4g THF were added to the polymerization kettle in sequence. The temperature was raised to 66°C, and 16.1mmol n-butyl lithium was added to start the reaction for 80min. Then, 270g macromolecular brominating agent and 1.7g THF were added to the polymerization kettle. The temperature was raised to 87°C and the reaction was carried out for 93min. Finally, 43g isoprene was added to the polymerization kettle and the end-capping reaction was carried out for 36min until no free monomers were present. The gel was wet condensed and dried to obtain the halogenated grafting agent S4, in which the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:1.1:38:5.9.

After testing, the halogenated grafting agent S4 had an Mn of 36100, an Mw/Mn of 3, a bromine content of 4.68%, and an apparent viscosity of 23 mPa·s at 25°C.

Preparation Example 5

(1) Preparation of macromolecular brominating agent: First, in a 15L stainless steel reactor with a jacket, argon gas was replaced 4 times, and 1800g of cyclohexane, 1000g of 2-bromo-1-propylene, and 4.5g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 58°C, 1.2g of BPO was added and reacted for 5.6h; then 35g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 35min until no free monomer was present. After the reaction was completed, the macromolecular brominating agent was obtained by washing and drying;

(2) Preparation of halogenated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon was introduced and replaced four times, and 2700g of cyclohexane, 760g of p-ethylstyrene, and 4.8g of THF were added to the polymerization kettle in sequence. The temperature was raised to 68°C, and 16.8mmol of n-butyl lithium was added to start the reaction for 85min. Then, 240g of a macromolecular brominating agent and 1.9g of THF were added to the polymerization kettle. The temperature was raised to 88°C and the reaction was carried out for 96min. Finally, 45g of isoprene was added to the polymerization kettle and the end-capping reaction was carried out for 38min until no free monomers were present. The gel was wet-condensed and dried to obtain a halogenated grafting agent S5, in which the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:1.1:38:5.9.

After testing, the halogenated grafting agent S5 had an Mn of 38200, an Mw/Mn of 3.3, a bromine content of 4.45%, and an apparent viscosity of 26 mPa·s at 25°C.

Preparation Example 6

(1) Preparation of macromolecular brominating agent: First, in a 15L stainless steel reactor with a jacket, argon gas was replaced 4 times, and 2000g of cyclohexane, 1000g of 2-bromo-1-butene, and 5g of tert-dodecyl mercaptan were added to the reactor in sequence, stirred and mixed, and heated. When the temperature of the reactor reached 60°C, 1.5g of DCP was added and reacted for 6h; then 40g of 1,3-butadiene was added to the polymerization reactor for end-capping, and the reaction was continued for 40min until no free monomer was present. After the reaction was completed, the macromolecular brominating agent was obtained by washing and drying;

(2) Preparation of halogenated grafting agent: First, in a 15L stainless steel reactor with a jacket, argon was introduced for 4 times, and 3000g of cyclohexane, 800g of p-butylstyrene, and 5g of THF were added to the polymerization kettle in sequence. The temperature was raised to 70°C, and 17.3mmol of n-butyllithium was added to start the reaction for 90min. Then, 200g of a macromolecular brominating agent and 2g of THF were added to the polymerization kettle. The temperature was raised to 90°C and the reaction was carried out for 100min. Finally, 50g of isoprene was added to the polymerization kettle and the end-capping reaction was carried out for 40min until no free monomers were present. The gel was wet-condensed and dried to obtain a halogenated grafting agent S6, in which the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:1:25:6.25.

After testing, the halogenated grafting agent S6 had a Mn of 39600, a Mw/Mn of 3.5, a bromine content of 4.12%, and an apparent viscosity of 30 mPa·s at 25°C.

Preparation Example 7

The halogenated grafting agent was prepared according to the method of Preparation Example 1, except that the amount of 1,3-butadiene added during the preparation process was 20 g, and other conditions remained unchanged, to obtain the halogenated grafting agent S7, wherein the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:1.34:67:5.

The results showed that the Mn of the halogenated grafting agent S7 was 30600, the Mw/Mn was 2.1, the bromine content was 5.92%, and the apparent viscosity at 25°C was 9.2 mPa·s.

Preparation Example 8

A halogenated grafting agent was prepared according to the method of Preparation Example 1, except that 30 g of 1,3-butadiene was added during the preparation process to obtain a halogenated grafting agent S8, wherein the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:1.94:67:5.

After testing, the halogenated grafting agent S8 had a Mn of 31000, a Mw/Mn of 2.2, a bromine content of 5.91%, and an apparent viscosity of 11.2 mPa·s at 25°C.

Preparation Example 9

The halogenated grafting agent was prepared according to the method of Preparation Example 1, except that the amount of p-methylstyrene added during the preparation process was 700 g, and other conditions remained unchanged, to obtain the halogenated grafting agent S9, wherein the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.57:57:4.

After testing, the halogenated grafting agent S9 had a Mn of 33,000, a Mw/Mn of 2.5, a bromine content of 5.23%, and an apparent viscosity of 16 mPa·s at 25°C.

Preparation Example 10

The halogenated grafting agent was prepared according to the method of Preparation Example 1, except that the amount of p-methylstyrene added during the preparation process was 800 g, and other conditions remained unchanged, to obtain the halogenated grafting agent S10, wherein the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.49:50:4.

The results showed that the Mn of the halogenated grafting agent S10 was 35000, the Mw/Mn was 2.9, the bromine content was 4.76%, and the apparent viscosity at 25°C was 26 mPa·s.

Preparation Example 11

The halogenated grafting agent was prepared according to the method of Preparation Example 1, except that vinyl chloride was used instead of vinyl bromide in Preparation Example 1 during the preparation process, and other conditions remained unchanged to obtain halogenated grafting agent S11, wherein the mass ratio of the structural units from vinyl chloride, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.67:67:5.

The results showed that the Mn of the halogenated grafting agent S11 was 30100, the Mw/Mn was 2.1, the chlorine content was 5.72%, and the apparent viscosity at 25°C was 5.7 mPa·s.

Preparation Example 12

In a 15L stainless steel reactor with a jacket, argon gas was replaced twice, and 1000g of cyclohexane, 1000g of vinyl bromide, 600g of p-methylstyrene and 2g of tert-dodecyl mercaptan were added to the reactor in turn, stirred and heated, and when the temperature of the reactor reached 50°C, 0.1g of BPO was added and reacted for 4h. Finally, 30g of isoprene was added to the polymerization kettle and the end-capping reaction was carried out for 30min until no free monomers were present. The gel was wet-coagulated and dried to obtain the halogenated grafting agent S12, in which the mass ratio of the structural units from vinyl bromide, p-methylstyrene and isoprene was 100:17:5.

After testing, the halogenated grafting agent S12 had a Mn of 50,000, a Mw/Mn of 4, a bromine content of 12.1%, and an apparent viscosity of 35 mPa·s at 25°C.

Preparation Example 13

The halogenated grafting agent was prepared according to the method of Preparation Example 1, except that in the preparation process of the halogenated grafting agent in step (2), the amount of the macromolecular brominating agent added was 200 g, and other conditions remained unchanged, to obtain the halogenated grafting agent S13, wherein the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.34:33:5.

The halogenated grafting agent S13 was tested to have a Mn of 25,000, a Mw/Mn of 1.5, a bromine content of 4.91%, and an apparent viscosity of 5 mPa·s at 25°C.

Preparation Example 14

The halogenated grafting agent was prepared according to the method of Preparation Example 1, except that in the preparation process of the halogenated grafting agent in step (2), the amount of the macromolecular brominating agent added was 300 g, and other conditions remained unchanged, to obtain the halogenated grafting agent S14, wherein the mass ratio of the structural units from vinyl bromide, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.5:50:5.

The halogenated grafting agent S14 was tested to have a Mn of 28,000, a Mw/Mn of 1.7, a bromine content of 5.38%, and an apparent viscosity of 7 mPa·s at 25°C.

Preparation Comparative Example 1

A halogenated grafting agent was prepared according to the method of Preparation Example 1, except that in the preparation process of the halogenated grafting agent in step (2), styrene was used instead of p-methylstyrene. Other conditions remained unchanged to obtain a halogenated grafting agent D1, in which the mass ratio of the structural units derived from vinyl bromide, 1,3-butadiene, styrene and isoprene was 100:0.67:67:5.

The results showed that the Mn of the halogenated grafting agent D1 was 23000, the Mw/Mn was 1.9, the bromine content was 5.98%, and the apparent viscosity at 25°C was 3.8 mPa·s.

Preparation Comparative Example 2

A halogenated grafting agent was prepared according to the method of Preparation Example 1, except that ethylene was used instead of vinyl bromide in the preparation of the macromolecular brominating agent in step (1), and other conditions remained unchanged to obtain a halogenated grafting agent D2, in which the mass ratio of the structural units derived from ethylene, 1,3-butadiene, p-methylstyrene and isoprene was 100:0.67:67:5.

After testing, the halogenated grafting agent D2 had an Mn of 21000, an Mw/Mn of 2.4, a bromine content of 0%, and an apparent viscosity of 3.1 mPa·s at 25°C.

Example 1

First, in a 4L stainless steel reactor with a jacket, nitrogen was replaced three times, 700g of methyl chloride, 300g of cyclohexane, and 20g of the halogenated grafting agent S1 obtained in Preparation Example 1 were added to the polymerization reactor, and stirred and dissolved for 40min until completely dissolved; then when the temperature was lowered to -70°C, 500g of methyl chloride, 500g of isobutylene, and 15g of isoprene were added in sequence, and stirred and mixed until the temperature of the polymerization system dropped to -80°C, and then 50g of methyl chloride, 1.05g of sesquiethylaluminum chloride and 0.011g of HCl were mixed and aged for 40min at -90°C, and then added together to the polymerization system and stirred for reaction for 3h, and finally 20g of methanol was added, the material was condensed, washed, and dried to obtain a brominated branched butyl rubber product, in which the mass ratio of the structural units from isobutylene, isoprene and halogenated grafting agent S1 was 100:3:4. Sampling and analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Embodiment 2-14

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the halogenated grafting agent S1 was replaced by any one of the halogenated grafting agents S2-S14, and other conditions remained unchanged to obtain the halogenated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Embodiment 15

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the amount of halogenated grafting agent S1 added during the preparation process was 25 g, and other conditions remained unchanged to obtain a brominated branched butyl rubber product. The mass ratio of the structural units from isobutylene, isoprene and halogenated grafting agent S1 was 100:3:5. Sampling analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Example 16

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the halogen The amount of halogenated grafting agent S1 added was 30 g, and other conditions remained unchanged to obtain a brominated branched butyl rubber product. Among them, the mass ratio of the structural units from isobutylene, isoprene and halogenated grafting agent S1 was 100:3:6. Sampling analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Embodiment 17

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the amount of halogenated grafting agent S1 added during the preparation process was 35 g, and other conditions remained unchanged to obtain a brominated branched butyl rubber product. The mass ratio of the structural units from isobutylene, isoprene and halogenated grafting agent S1 was 100:3:7. Sampling analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Embodiment 18

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the amount of isoprene added during the preparation process was 20 g, and other conditions remained unchanged to obtain a brominated branched butyl rubber product. The mass ratio of the structural units from isobutylene, isoprene and halogenated grafting agent S1 was 100:4:4. Sampling analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Embodiment 19

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the amount of isoprene added during the preparation process was 25 g, and other conditions remained unchanged to obtain a brominated branched butyl rubber product. The mass ratio of the structural units from isobutylene, isoprene and halogenated grafting agent S1 was 100:5:4. Sampling analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Embodiment 20

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that 1.05 g of sesquiethylaluminum chloride and 0.011 g of HCl were replaced with g of aluminum chloride, and the other conditions remained unchanged to obtain the brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test performance is shown in Table 1.

Comparative Example 1

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the halogenated grafting agent S1 was replaced by the halogenated grafting agent D1, and other conditions remained unchanged to obtain the brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Comparative Example 2

The brominated branched butyl rubber product was prepared according to the method of Example 1, except that the halogenated grafting agent S1 was replaced by the halogenated grafting agent D2, and other conditions remained unchanged to obtain the brominated branched butyl rubber product. Sampling and analysis: Standard samples were prepared, and the test properties are shown in Table 1.

Table 1 Properties of brominated branched butyl rubber

It can be seen from the results in Table 1 that, compared with the comparative example, the halogenated branched butyl rubber product prepared in the embodiment of the present invention has better damping performance, better air tightness and better mechanical properties.

The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims (19)

1. A halogenated grafting agent, characterized in that the halogenated grafting agent contains a structural unit A, an optional structural unit B, a structural unit C and a structural unit D; wherein the structural unit A has a structure shown in formula (1); the structural unit C has a structure shown in formula (2); the structural unit B is connected to the structural unit A and the structural unit C respectively; the structural unit D is a terminal capping structural unit; the structural unit B and the structural unit D are independently derived from a conjugated diene;
   

   Wherein, _R1 and _R2 are each independently hydrogen or a _C1 - _C5 straight chain or branched alkyl group; _R3 is a _C1 - _C8 straight chain or branched alkyl group; _R4 and _R5 are each independently hydrogen or a _C1 - _C4 straight chain or branched alkyl group; and X is a halogen.
2. The halogenated grafting agent according to claim 1, wherein _R1 and _R2 are each independently hydrogen or a _C1 - _C3 straight chain or branched alkyl group; _R3 is a _C1 - _C5 straight chain or branched alkyl group; _R4 and _R5 are each independently hydrogen or a _C1 - _C2 alkyl group; X is at least one selected from Cl and Br;

   And/or, the conjugated diene is butadiene and/or isoprene.
3. The halogenated grafting agent according to claim 1 or 2, wherein the mass ratio of the structural unit A, the structural unit B, the structural unit C and the structural unit D is 100:0-2:15-70:3-7;

   And/or, the structural unit B is derived from butadiene; and the structural unit D is derived from isoprene.
4. The halogenated grafting agent according to claim 1 or 2, wherein the mass percentage of halogen in the halogenated grafting agent is 3wt%-7wt%;

   and/or, the number average molecular weight of the halogenated grafting agent is 25,000-50,000 g/mol;

   And/or, the molecular weight distribution index of the halogenated grafting agent is 1.5-4;

   And/or, the halogenated grafting agent is a block copolymer or a random copolymer;

   And/or, the apparent viscosity of the halogenated grafting agent at 25° C. is 5-35 mPa·s.
5. A method for preparing a halogenated grafting agent, characterized in that the preparation method comprises:

   S1. Under polymerization reaction conditions and in the presence of an initiator, polymerizing the monomer represented by formula (I) and the monomer represented by formula (II) to obtain a polymerization product;

   Alternatively, (1) the monomer represented by formula (I) is reacted in the presence of a molecular weight regulator, a first solvent and a first initiator. A first polymerization reaction is carried out, and a second conjugated diene is optionally added to carry out a first end-capping reaction to obtain a first product;

   (2) subjecting the monomer represented by formula (II) to a second polymerization reaction in the presence of a structure regulator, a second solvent, and a second initiator to obtain a second product, and then adding the first product to conduct a third polymerization reaction to obtain a third product;

   S2, subjecting the polymer product obtained in step S1 or the third product obtained in step (2) to a second end-capping reaction with the first conjugated diene to obtain the halogenated grafting agent;
   

   Wherein, _R1 and _R2 are each independently hydrogen or a _C1 - _C5 straight chain or branched alkyl group; _R3 is a _C1 - _C8 straight chain or branched alkyl group; _R4 and _R5 are each independently hydrogen or a _C1 - _C4 straight chain or branched alkyl group; and X is a halogen.
6. The preparation method according to claim 5, wherein the mass ratio of the monomer represented by formula (I), the second conjugated diene, the monomer represented by formula (II) and the first conjugated diene is 100:0-2:15-70:3-7.
7. The preparation method according to claim 5 or 6, wherein the monomer represented by formula (II) is a halogenated olefin;

   And/or, the monomer represented by formula (I) is p-alkylstyrene;

   and/or, the first conjugated diene and the second conjugated olefin are each independently butadiene and/or isoprene;

   And/or, the first initiator is an organic peroxide;

   and/or, the second initiator is a hydrocarbon monolithium compound R-Li, wherein R is a C ₁ -C ₂₀ saturated aliphatic hydrocarbon group, a C ₃ -C ₂₀ alicyclic hydrocarbon group, a C ₆ -C ₂₀ aromatic hydrocarbon group or a composite group of the above groups;

   and/or, the molecular weight regulator is selected from at least one of tert-decyl mercaptan, tert-dodecyl mercaptan, tert-tetradecyl mercaptan and tert-hexadecanethiol;

   and/or, the structure regulator is a polar organic compound;

   And/or, the first solvent and the second solvent are each independently a hydrocarbon solvent.
8. The preparation method according to claim 7, wherein the monomer represented by formula (II) is at least one selected from vinyl bromide, vinyl chloride, 1-bromo-1-propylene, 2-bromo-1-propylene, 1-bromo-1-butene and 2-bromo-1-butene;

   And/or, the monomer represented by formula (I) is selected from p-methylstyrene, p-ethylstyrene, p-propylstyrene At least one of olefins, p-n-butylstyrene, p-isobutylstyrene and p-isopentylstyrene;

   and/or, the first initiator is selected from at least one of dicumyl peroxide, cumyl hydroperoxide and benzoyl peroxide;

   and/or, the second initiator is at least one selected from n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium and dodecyllithium;

   and/or, the structure regulator is at least one selected from diethylene glycol dimethyl ether, tetrahydrofuran, ethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether and triethylamine;

   And/or, the first solvent and the second solvent are each independently selected from at least one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene.
9. The preparation method according to claim 5 or 6, wherein the conditions of the first polymerization reaction include: a reaction temperature of 50-60° C. and a reaction time of 4-6 h;

   And/or, the conditions of the first end-capping reaction include: reaction temperature of 50-60° C., reaction time of 20-40 min;

   And/or, the conditions of the second polymerization reaction include: reaction temperature of 60-70°C, reaction time of 70-90min;

   And/or, the conditions of the third polymerization reaction include: reaction temperature of 80-90° C., reaction time of 80-100 min;

   And/or, the conditions of the second end-capping reaction include: reaction temperature of 80-90° C., reaction time of 30-40 min.
10. A halogenated grafting agent obtained by the preparation method according to any one of claims 5 to 9.
11. A use of the halogenated grafting agent according to any one of claims 1 to 4 and 10 as a grafting agent in the preparation of diene rubber.
12. The use according to claim 11, wherein the diene rubber is butyl rubber.
13. A halogenated branched butyl rubber, characterized in that the halogenated branched butyl rubber comprises: a structural unit E derived from isobutylene, a structural unit F derived from isoprene and a structural unit G derived from a halogenated grafting agent; wherein the halogenated grafting agent is the halogenated grafting agent described in any one of claims 1 to 4 and 10.
14. The halogenated branched butyl rubber according to claim 13, wherein the mass ratio of the structural unit E, the structural unit F and the structural unit G is 100:2-6:3-8 based on the total weight of the halogenated branched butyl rubber.
15. A method for preparing halogenated branched butyl rubber, characterized in that the preparation method comprises the following steps:

    In the presence of a diluent, an organic solvent and a co-initiator, isobutylene, isoprene and the halogenated grafting agent according to any one of claims 1 to 4 and 10 are subjected to cationic polymerization to obtain the halogenated branched butyl rubber.
16. The preparation method according to claim 15, wherein the mass ratio of isobutylene, isoprene and the halogenated grafting agent is 100:2-6:3-8;

    And/or, the diluent is a halogenated alkane, wherein the halogen atom in the halogenated alkane is Cl or Br, and the number of carbon atoms in the halogenated alkane is 1-4;

    And/or, the co-initiator comprises a protonic acid and an alkyl aluminum halide; the molar ratio of the protonic acid to the alkyl aluminum halide is 1:10-100;

    and/or, the mass ratio of the isobutylene to the co-initiator is 100:0.01-0.5;

    And/or, the conditions of the cationic polymerization include: the polymerization temperature is -100°C to -80°C; the cationic polymerization time is 3-4h.
17. The preparation method according to claim 16, wherein the protonic acid is selected from at least one of HCl, HF, HBr, H ₂ SO ₄ , H ₂ CO ₃ , H ₃ PO ₄ and HNO ₃ ;

    The alkyl aluminum halide is at least one selected from diethylaluminum monochloride, diisobutylaluminum monochloride, methylaluminum dichloride, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, n-propylaluminum dichloride, isopropylaluminum dichloride, dimethylaluminum chloride and ethylaluminum chloride.
18. A halogenated branched butyl rubber obtained according to the preparation method according to any one of claims 15 to 17.
19. Use of the halogenated branched butyl rubber according to claim 13, 14 or 18 in automobiles and electronic appliances.