CN116355153A

CN116355153A - Brominated grafting agent and preparation method and application thereof

Info

Publication number: CN116355153A
Application number: CN202111631172.5A
Authority: CN
Inventors: 徐典宏; 李旭晖; 杨珊珊; 孟令坤; 翟云芳; 朱晶; 燕鹏华
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-06-30

Abstract

The invention provides a brominated grafting agent and a preparation method and application thereof, wherein the brominated grafting agent has a structure shown in a formula 1, in the formula 1, PS is a styrene homo-block, D is a dibrominated isoprene homo-block, E is a dibrominated 1, 3-butadiene homo-block, B is a 1, 3-butadiene homopolymer with a number average molecular weight not higher than 1000, k is not less than 1, l is not less than 1, m is not less than 1, and n is not less than 1; in the brominated grafting agent, the mass percentage of bromine element is 18-23%. The brominated grafting agent can be used as a modifier for the butyl rubber to modify the butyl rubber into brominated butyl rubber, and the properties of the brominated butyl rubber including ageing resistance, vulcanization processability and the like are obviously improved, so that the application range of the butyl rubber is widened.

Description

Brominated grafting agent and preparation method and application thereof

Technical Field

The invention relates to a grafting agent, in particular to a brominated grafting agent, a preparation method and application thereof, and belongs to the technical field of high polymer materials.

Background

As one of the most important synthetic Rubber varieties, butyl Rubber (IIR for short) produced by cationic polymerization and copolymerization of isobutylene and a small amount of isoprene as raw materials is widely used in the fields of inner tubes, inner liners, curing bladders, and the like for manufacturing tires for vehicles.

However, the molecular chain of the butyl rubber has higher unsaturation degree and the substituent methyl groups are symmetrically arranged, and the molecular structure determines the unavoidable problems of poor ozone aging resistance, high Mooney viscosity, long vulcanization scorching time, low vulcanization speed, poor green strength, poor air tightness and the like, so that the processability of the butyl rubber cannot meet the processing requirements and application scenes of gradual diversification, and the molecular structure becomes the bottleneck of expanding the application of the butyl rubber material.

Therefore, how to modify butyl rubber to have more excellent application performance is a technical problem to be solved by the technicians in the field.

Disclosure of Invention

The invention provides a brominated grafting agent which is used as a modifier of p-butyl rubber, can modify butyl rubber into brominated butyl rubber, and can obviously improve properties of the brominated butyl rubber including vulcanization processability, mechanical properties and the like, thereby widening the application range of the butyl rubber.

The invention also provides a preparation method of the brominated grafting agent, which can modify butyl rubber and ensure that the modified brominated butyl rubber has excellent processability and mechanical properties.

The invention also provides a brominated butyl rubber which comprises the brominated grafting agent, and therefore, has excellent processability, and is particularly characterized by lower unsaturation, air permeability and Mooney viscosity, shorter vulcanization scorch time and vulcanization time, higher tensile strength and longer static ozone performance break time.

The invention also provides a rubber product which is obtained by processing the brominated butyl rubber, and has excellent performances in ageing resistance, mixing effect, mechanical property, vulcanization processability and the like.

The invention provides a brominated grafting agent, which has a structure shown in a formula 1:

wherein PS is a styrene homo-block, D is a dibrominated isoprene homo-block, E is a dibrominated 1, 3-butadiene homo-block, B is a 1, 3-butadiene homopolymer with a number average molecular weight not higher than 1000, k is not less than 1, l is not less than 1, m is not less than 1, n is not less than 1;

in the brominated grafting agent, the mass percentage of bromine element is 18-23%.

The brominated grafting agent as described above, wherein the brominated grafting agent has a number average molecular weight of 100000 ～ 130000 and a molecular weight distribution of 16.27 to 17.86.

A brominated grafting agent as described above, wherein the brominated grafting agent is prepared by a process comprising:

the coupling raw material system is reacted for 60 to 180 minutes at the temperature of between 60 and 80 ℃ and then the reaction is stopped, and the coupling agent is obtained by extraction;

the first raw material system is reacted for 20 to 30 minutes at the temperature of between 40 and 50 ℃, then a first monomer and a first structure regulator A are added into the system, and the reaction is carried out for 40 to 50 minutes at the temperature of between 50 and 60 ℃ to obtain a first block system; adding a first organic brominating agent and a first molecular weight regulator into the first block system, heating to 70-80 ℃, adding a first organic brominating initiator, and reacting for 3-4 hours to obtain a first brominating system;

the second raw material system is reacted for 30 to 40 minutes at the temperature of between 40 and 50 ℃, and then a second monomer is added into the system, and is reacted for 50 to 60 minutes at the temperature of between 50 and 60 ℃ to obtain a second block system; adding a second organic brominating agent and a second molecular weight regulator into the second block system, heating to 70-80 ℃, adding a second organic brominating initiator, and reacting for 2-3 hours to obtain a second brominating system;

adding a third monomer and a third structure regulator A into the third raw material system after reacting for 50-60min at 40-50 ℃, and then reacting for 40-50min at 50-60 ℃ to obtain a third block system; adding a third organic brominating agent and a third molecular weight regulator into the third block system, heating to 70-80 ℃, adding a third organic brominating initiator, and reacting for 3-4 hours to obtain a third brominating system;

Reacting the fourth raw material system at 60-70 ℃ for 30-40min to obtain a fourth block system;

adding the second bromination system, the third bromination system and the fourth block system into the first bromination system, adding the coupling agent at 80-90 ℃ for reaction for 140-160min, and then adding the activating end capping agent for reaction for 20-30min to obtain a brominated grafting agent;

wherein the coupling raw material system comprises 3, 9-dioxy [5.5] spiro undecane, a halogenating agent and a catalyst; the first raw material system comprises isoprene, a first structure regulator B and a first polymerization initiator; the second raw material system comprises 1, 3-butadiene, a second structure regulator and a second polymerization initiator; the third raw material system comprises isoprene, a third structure regulator B and a third polymerization initiator; the fourth raw material system comprises styrene, a fourth structure regulator and a fourth polymerization initiator; the first monomer and the activated end-capping agent are 1, 3-butadiene, and the second monomer and the third monomer are styrene.

The brominated grafting agent as described above, wherein the mass ratio of 3, 9-dioxo [5.5] spiro undecane, halogenating agent and catalyst is (10-30): (70-90): (1-5); and/or the number of the groups of groups,

The mass ratio of the brominating agent to the isoprene, the first structure regulator B, the first monomer, the first structure regulator A, the first molecular weight regulator and the first organic brominating initiator in the first raw material system is 1: (0.1-0.2): (0.001-0.003): (0.2-0.3): (0.001-0.003): (0.002-0.004): (0.005-0.03); and/or the number of the groups of groups,

the mass ratio of the brominating agent to the 1, 3-butadiene, the second structure regulator, the second monomer, the second organic brominating initiator and the second molecular weight regulator in the second raw material system is 1: (0.1-0.2): (0.001-0.003): (0.005-0.02): (0.001-0.003); and/or the number of the groups of groups,

the mass ratio of the brominating agent to the isoprene, the third structure regulator B, the third monomer, the third structure regulator A, the third organic brominating initiator and the third molecular weight regulator in the third raw material system is 1: (0.2-0.3): (0.001-0.003): (0.2-0.3): (0.001-0.003): (0.005-0.03): (0.001-0.003); and/or the number of the groups of groups,

the mass ratio of the brominating agent to the styrene in the fourth raw material system to the fourth structure regulator is 1: (0.2-0.3): (0.001-0.003);

wherein the brominating agent consists of the first organic brominating agent, the second organic brominating agent and the third organic brominating agent, and the mass ratio of the organic first brominating agent, the second organic brominating agent and the third organic brominating agent is (0.4-0.5): (0.2-0.3): (0.2-0.4).

A brominated grafting agent as described above, wherein the molar ratio of the coupling agent to the polymerization initiator is (2:1) - (5:1);

the polymerization initiator is composed of the first, second, third and fourth polymerization initiators.

The invention also provides a preparation method of the brominated grafting agent, which comprises the following steps:

wherein the coupling raw material system comprises 3, 9-dioxy [5.5] spiro undecane, a halogenating agent and a catalyst; the first raw material system comprises isoprene, a first structure regulator B and a first polymerization initiator; the second raw material system comprises 1, 3-butadiene, a second structure regulator and a second polymerization initiator; the third raw material system comprises isoprene, a third structure regulator B and a third polymerization initiator; the fourth raw material system comprises styrene, a fourth structure regulator and a fourth polymerization initiator; the first monomer and the activated end-capping agent are 1, 3-butadiene, and the second monomer and the third monomer are styrene;

The brominated grafting agent has a structure shown in a formula 1,

The invention also provides a brominated butyl rubber, wherein the brominated butyl rubber is obtained by polymerizing the brominated grafting agent or the brominated grafting agent prepared by the preparation method of the brominated grafting agent and a system comprising isobutene and isoprene;

the mass ratio of the brominated grafting agent to the isobutene to the isoprene is (8-12): (85-90): (7-9).

A brominated butyl rubber as described above, wherein the brominated butyl rubber is prepared by a process comprising:

adding a first diluent, isobutene and isoprene into a solution system of the brominated grafting agent at the temperature of-90 to-80 ℃ and controlling the temperature to be-100 to-90 ℃ to obtain a first system;

mixing a second diluent and a co-initiator at the temperature of minus 95 ℃ to minus 85 ℃ and aging for 30 to 40 minutes, adding an aging system into the first system to react for 6 to 8 hours, and stopping the reaction to obtain the brominated butyl rubber.

The brominated butyl rubber as described above, wherein the mass ratio of the reaction main body, the first diluent, the second diluent and the co-initiator is 1: (1-2): (0.1-0.2): (0.002-0.005);

the mass of the reaction main body is the total mass of the brominated grafting agent, isobutene and isoprene.

The invention also provides a rubber product, wherein the rubber product is processed by the brominated butyl rubber.

The brominated grafting agent is used for modifying butyl rubber, and the special structure and bromine content of the brominated butyl rubber can ensure that the modified brominated butyl rubber has the characteristics of stable bromine structure, low saturation and low Mooney viscosity, so that the brominated butyl rubber is beneficial to improving the vulcanization processing characteristics (shorter vulcanization scorch time and positive vulcanization time), the mixing effect (lower Mooney viscosity), the mechanical property (higher tensile strength), the ageing resistance (longer static ozone property break time) and the airtight property (lower air permeability).

Therefore, the rubber product obtained by processing the brominated butyl rubber has excellent performance in vulcanization processing characteristics, mixing effect, mechanical properties, aging resistance, air tightness and the like.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The first aspect of the present invention provides a brominated grafting agent having a structure represented by the following formula 1:

in the bromination grafting agent, the mass percentage of bromine element is 18-23%.

The brominated grafting agent is used for carrying out bromination modification on butyl rubber to obtain brominated butyl rubber. The invention is not limited to the molecular weight of the brominated grafting agent, as long as the polymer satisfying the structure and the mass percentage of bromine element is the brominated grafting agent of the invention.

The brominated grafting agent is a ternary four-hetero-arm star-block brominated grafting agent, namely the grafting agent is formed by cross connection of four different structural units, wherein the first structural unit comprises a block copolymer of a dibrominated isoprene homo-block D and a dibrominated 1, 3-butadiene homo-block E, the second structural unit comprises a block copolymer of a dibrominated 1, 3-butadiene homo-block E and a styrene homo-block PS, the third structural unit comprises a block copolymer of a styrene homo-block PS and a dibrominated isoprene homo-block D, and the fourth structural unit comprises a styrene homo-block PS.

The structure of the styrene homo-block PS is shown as 1-a, the structure of the dibromo 1, 3-butadiene homo-block E is shown as 1-b, and the structure of the dibromo isoprene homo-block D is shown as 1-c.

The molecular weights of the three homo-blocks, i.e., o, p, q, may be any number of 1 or more.

In addition, the brominated grafting agent also comprises a blocking group B, wherein the blocking group B is used for improving the reactivity of the brominated grafting agent and butyl rubber so as to improve the modification efficiency of the butyl rubber. Specifically, the end-capping group B is a copolymer of 1, 3-butadiene and has a number average molecular weight of not more than 1000.

The brominated grafting agent has higher mass percent of bromine element, so that the brominated grafting agent has excellent stability, and particularly, the brominated grafting agent has excellent stability of a secondary carbon atom bromine structure, thereby being beneficial to solving the problem that butyl rubber is less in double bonds and difficult to vulcanize due to high saturation and improving vulcanization speed.

In addition, from the structure, the ternary four-hetero-arm star-shaped structure of the brominated grafting agent can destroy the regular molecular structure of butyl rubber, and the modified brominated butyl rubber can have lower Mooney viscosity by increasing the disorder of chain segments, so that the processing energy consumption of the brominated butyl rubber is greatly reduced, and the mixing effect of the brominated butyl rubber is improved.

It is also notable that the content of unsaturated double bonds in the brominated grafting agent is obviously lower, so that the introduction of unsaturated double bonds into the butyl rubber can be avoided in the modification process, the saturation of the modified brominated butyl rubber is improved, and the modified brominated butyl rubber is excellent in ozone resistance and air tightness. In addition, the brominated grafting agent contains a large amount of benzene rings, and the benzene rings have high rigidity and high steric hindrance, so that the mechanical strength of the brominated butyl rubber can be improved.

Therefore, the brominated grafting agent has the characteristics of stable bromine structure, low Mooney viscosity, high saturation and high disorder, and the brominated butyl rubber modified by the brominated grafting agent is favorable for improving the vulcanization processability, the mixing effect, the ozonization resistance, the mechanical property and the air tightness of the modified brominated butyl rubber, so that the modified brominated butyl rubber has excellent processability to meet various application requirements.

Further, the inventors have found that when the number average molecular weight of the brominated grafting agent is 100000 ～ 130000 and the molecular weight distribution is 16.27 to 17.86, further promotion of the processability of brominated butyl rubber can be achieved with higher economic efficiency.

The present invention is not limited to the method of preparing the brominated grafting agent, and in one embodiment, the brominated grafting agent is prepared by a method comprising the following process.

The method comprises a preparation step of a coupling agent, a preparation step of a first bromination system, a preparation step of a second bromination system, a preparation step of a third bromination system, a preparation step of a fourth block system and a coupling activation step, wherein the coupling activation step is a process of coupling the first bromination system, the second bromination system, the third bromination system and the fourth block by using the coupling agent and then blocking and activating. It will be appreciated that there is no relationship between the preparation steps of the coupling agent, the first bromination system, the second bromination system, the third bromination system, and the fourth block system, and therefore, the coupling agent, the first bromination system, the second bromination system, the third bromination system, and the fourth block system may be prepared separately and independently of each other.

These six steps are described below.

The coupling agent of the invention is 1, 5-dihalo-3, 3-di (2-haloethyl) pentane, and the preparation steps comprise: the coupling raw material system is reacted for 60 to 180 minutes at the temperature of between 60 and 80 ℃ to terminate the reaction, and then the coupling agent is obtained by extraction; wherein the coupling raw material system comprises 3, 9-dioxy [5.5] spiro undecane, halogenating agent and catalyst.

In the invention, after the coupling raw material system reacts for 60-180min, a terminator can be added into the system to terminate the reaction, and then an extractant is added for extraction, separation, washing and drying to obtain the coupling agent; wherein the terminator is sodium hydroxide aqueous solution, and the mass percentage of the sodium hydroxide aqueous solution can be 20-40%; the extractant is chloromethane.

The first bromination system of the present invention refers to a system comprising a block copolymer of a dibromoisoprene homo-block and a dibromo1, 3-butadiene homo-block. Specifically, a first raw material system is reacted for 20-30min at 40-50 ℃, then a first monomer and a first structure regulator A are added into the system, and then the reaction is carried out for 40-50min at 50-60 ℃ to obtain a first block system; adding a first organic brominating agent and a first molecular weight regulator into the first block system, heating to 70-80 ℃, adding a first organic brominating initiator, and reacting for 3-4 hours to obtain a first brominating system; wherein the first raw material system comprises isoprene, a first structure regulator B and a first polymerization initiator, and the first monomer is 1, 3-butadiene.

In the process, isoprene monomers are homopolymerized to obtain isoprene homopolymerized blocks, then 1, 3-butadiene which is added as a first monomer is homopolymerized, and the generated 1, 3-butadiene homopolymerized blocks are segmented with isoprene homopolymerization to obtain a block copolymer of the 1, 3-butadiene homopolymerized blocks and the isoprene homopolymerized blocks. Then, the addition of the first organic brominating agent can generate free radical bromination addition reaction with the block copolymer of the 1, 3-butadiene homopolymerization block and the isoprene homopolymerization block to obtain the block copolymer of the dibrominated 1, 3-butadiene homopolymerization block and the dibrominated isoprene homopolymerization block.

The second bromination system of this invention is a system comprising a block copolymer of a dibromo 1, 3-butadiene homo-block and a styrene homo-block. Specifically, the second raw material system is reacted at the temperature of 40-50 ℃ for 30-40min, then a second monomer is added into the system, and the reaction is carried out at the temperature of 50-60 ℃ for 50-60min, thus obtaining a second block system; adding a second organic brominating agent and a second molecular weight regulator into the second block system, heating to 70-80 ℃, adding a second organic brominating initiator, and reacting for 2-3h to obtain a second brominating system; wherein the second raw material system comprises 1, 3-butadiene, a second structure regulator and a second polymerization initiator, and the second monomer is styrene.

In the process, 1, 3-butadiene monomer is homopolymerized to obtain a 1, 3-butadiene homopolymerized block, then the added second monomer styrene is homopolymerized, and the generated styrene homopolymerized block is segmented with 1, 3-butadiene homopolymerized block to obtain a block copolymer of the styrene homopolymerized block and the 1, 3-butadiene homopolymerized block. Then, the addition of the second organic brominating agent can generate free radical bromination addition reaction with the block copolymer of the styrene homopolymerization block and the 1, 3-butadiene homopolymerization block to obtain the block copolymer of the styrene homopolymerization block and the dibrominated 1, 3-butadiene homopolymerization block.

The third feed system of the present invention is a system comprising a block copolymer of styrene homo-blocks and dibrominated isoprene homo-blocks. Specifically, a third raw material system is reacted for 50-60min at the temperature of 40-50 ℃, then a third monomer and a third structure regulator A are added into the system, and then the reaction is carried out for 40-50min at the temperature of 50-60 ℃ to obtain a third block system; adding a third organic brominating agent and a third molecular weight regulator into the third block system, heating to 70-80 ℃, adding a third organic brominating initiator, and reacting for 3-4 hours to obtain a third brominating system; wherein the third raw material system comprises isoprene, a third structure regulator B and a third polymerization initiator, and the third monomer is styrene.

In the process, isoprene monomer is homopolymerized to obtain an isoprene homopolymerized block, then styrene which is added as a third monomer is homopolymerized, and the generated styrene homopolymerized block is segmented with isoprene homopolymerization to obtain a block copolymer of the styrene homopolymerized block and the isoprene homopolymerized block. And then, the addition of the third organic brominating agent can generate free radical bromination addition reaction with the block copolymer of the styrene homopolymerization block and the isoprene homopolymerization block to obtain the block copolymer of the styrene homopolymerization block and the dibrominated isoprene homopolymerization block.

The fourth block system of the present invention is a system comprising styrene homo-blocks. Specifically, the fourth raw material system is reacted at 60-70 ℃ for 30-40min to obtain a fourth block system, wherein the fourth raw material system comprises styrene, a fourth structure regulator and a fourth polymerization initiator. In this process, homopolymerization of the styrene monomer occurs to give a styrene homopolymerization block.

After the preparation of the coupling agent, the first bromination system, the second bromination system, the third bromination system and the fourth block system is completed, the second bromination system, the third bromination system and the fourth bromination system are added into the first bromination system, the coupling agent is added at 80-90 ℃ and reacts for 140-160min, and then the activating end capping agent is added and reacts for 20-30min, so that the brominated grafting agent is obtained. After the end capping reagent is added for reaction for 20-30min, the reaction system is subjected to post-treatment including discharging coagulation, washing and drying to finally obtain the brominated grafting reagent; wherein the activated end-capping agent is 1, 3-butadiene.

As mentioned previously, in the preparation of the first, second and third bromination systems, both the brominating agent employed and the brominating initiator are organic compounds, and thus the bromination process is a free radical addition reaction. On the one hand, the free radical addition reaction is beneficial to avoiding the generation of byproduct hydrogen bromide (HBr) and avoiding the molecular rearrangement of a bromine structure, so that the high bromine content and the high bromine structure stability of the brominated grafting agent are realized, and meanwhile, the alkaline washing recovery flow of the byproduct HBr is omitted, thereby shortening the process flow and reducing the production cost. On the other hand, the content of unsaturated double bonds in the brominated grafting agent is obviously reduced by the bromination reaction of free radical addition, and the introduction of unsaturated double bonds in the modification process of the butyl rubber is avoided, so that the saturation of the modified brominated butyl rubber is improved.

In the preparation process, the preparation of the brominated grafting agent with the target molecular weight can be realized by further controlling the dosage of each raw material, the preparation time and other factors.

As a preferred embodiment, when the mass ratio of 3, 9-dioxo [5.5] spirocyclic undecane, halogenating agent and catalyst is (10-30): (70-90): (1-5); and/or the number of the groups of groups,

The mass ratio of the brominating agent to isoprene, the first structure regulator B, the first monomer, the first structure regulator A, the first molecular weight regulator and the first organic brominating initiator in the first raw material system is 1: (0.1-0.2): (0.001-0.003): (0.2-0.3): (0.001-0.003): (0.002-0.004): (0.005-0.03); and/or the number of the groups of groups,

the mass ratio of the brominating agent to the 1, 3-butadiene, the second structure regulator, the second monomer, the second organic bromination initiator and the second molecular weight regulator in the second raw material system is 1: (0.1-0.2): (0.001-0.003): (0.005-0.02): (0.001-0.003); and/or the number of the groups of groups,

the mass ratio of the brominating agent to isoprene, the third structure regulator B, the third monomer, the third structure regulator A, the third organic bromination initiator and the third molecular weight regulator in the third raw material system is 1: (0.2-0.3): (0.001-0.003): (0.2-0.3): (0.001-0.003): (0.005-0.03): (0.001-0.003); and/or the number of the groups of groups,

the mass ratio of the brominating agent to the styrene in the fourth raw material system and the fourth structure regulator is 1: (0.2-0.3): (0.001-0.003);

wherein the brominating agent consists of a first organic brominating agent, a second organic brominating agent and a third organic brominating agent, and the mass ratio of the first organic brominating agent, the second organic brominating agent and the third organic brominating agent is (0.4-0.5): (0.2-0.3): (0.2-0.4) can increase the economic benefit of the preparation method by increasing the yield of the product.

In addition, the mass ratio of the brominating agent to the activating end capping agent is 1: (0.01-0.04).

It will be appreciated that the coupling feed system comprises deionized water in addition to the aforementioned composition; further, the mass ratio of the coupling main raw material to deionized water is 1: (1-2) the coupling main raw material consists of 3, 9-dioxy [5.5] spiro undecane and halogenating agent. And the mass ratio of the coupling main body raw material to the sodium hydroxide aqueous solution to the extractant is 1: (0.1-0.2): (2-3).

The first, second, third, and fourth feed systems comprise a solvent in addition to the foregoing composition; further, the mass of the solvent in each raw material system is 100-200% of the mass of the brominating agent. The solvent is selected from linear alkane, arene and cycloalkane, and may be selected from one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene, preferably hexane.

In addition, the preparation process is carried out in an oxygen-free and water-free environment, so that the reaction environment needs to be protected by inert gas at the beginning of the preparation.

In the above preparation process, the halogenating agent is liquid chlorine or liquid bromine, preferably liquid bromine.

The catalyst is HCl and CH ₃ Mixed aqueous solution of OH, wherein the molar concentration of HCl is 0.1-0.9 mol/L, CH ₃ The molar concentration of OH is 0.3-0.7mol/L.

The first organic brominating agent, the second organic brominating agent and the third organic brominating agent are each independently selected from one of N-bromosuccinimide, N-bromophthalimide, N '-dibromo-5, 5' -dimethylhydantoin, preferably N-bromophthalimide.

The first polymerization initiator, the second polymerization initiator, the third polymerization initiator and the fourth polymerization initiator are all hydrocarbyl mono-lithium compounds, namely RLi, wherein R is saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or composite group of the above groups containing 1-20 carbon atoms. The first polymerization initiator, the second polymerization initiator, the third polymerization initiator, and the fourth polymerization initiator are each independently selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium, dodecyllithium, preferably n-butyllithium. The amount of each initiator added is determined by the molecular weight of the target brominated grafting agent, for example, the amount of material of n-butyllithium is calculated by the following formula.

The first organic bromination initiator, the second organic bromination initiator and the third organic bromination initiator are all organic peroxides and are each independently selected from one of di-tert-butyl hydroperoxide (TBHP), 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide (BPDH), di-tert-butyl peroxide (DTBP) and dicumyl peroxide (DCP), preferably DTBP.

The first structure modifier a, the first structure modifier B, the second structure modifier, the third structure modifier a, the third structure modifier B, and the fourth structure modifier are all polar organic compounds for generating a solvation effect in the polymerization reaction. The first structure regulator A, the first structure regulator B, the second structure regulator, the third structure regulator A, the third structure regulator B and the fourth structure regulator are each independently selected from one of diethylene glycol dimethyl ether (2G), tetrahydrofuran (THF), diethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME) and triethylamine, preferably Tetrahydrofuran (THF).

The first molecular weight regulator, the second molecular weight regulator and the third molecular weight regulator are each independently selected from one of tertiary dodecyl mercaptan, tertiary tetradecyl mercaptan and tertiary hexadecyl mercaptan, preferably tertiary dodecyl mercaptan.

Further, the molar ratio of the coupling agent to the polymerization initiator is (2:1) - (5:1); wherein the polymerization initiator is composed of the first polymerization initiator, the second polymerization initiator, the third polymerization initiator and the fourth polymerization initiator.

The brominated grafting agent is an organic combination of a styrene homopolymerization block, an isoprene homopolymerization block, a 1, 3-butadiene homopolymerization block and a secondary bromine structure, and the parts are combined together and cooperatively exerted, so that the brominated grafting agent can be used for modifying butyl rubber, and the modified brominated butyl rubber has excellent vulcanization processability, mixing effect, mechanical property, ageing resistance and air tightness.

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

adding a second bromination system, a third bromination system and a fourth block system into the first bromination system, adding the coupling agent at 80-90 ℃ for reaction for 140-160min, and then adding an activated end capping agent for reaction for 20-30min to obtain a brominated grafting agent;

wherein the coupling raw material system comprises 3, 9-dioxy [5.5] spiro undecane, halogenating agent and catalyst; the first raw material system comprises isoprene, a first structure regulator B and a first polymerization initiator; the second raw material system comprises 1, 3-butadiene, a second structure regulator and a second polymerization initiator; the third raw material system comprises isoprene, a third structure regulator B and a third polymerization initiator; the fourth raw material system comprises styrene, a fourth structure regulator and a fourth polymerization initiator; the first monomer and the activated end-capping agent are 1, 3-butadiene, and the second monomer and the third monomer are styrene;

the brominated grafting agent has a structure shown in a formula 1,

The specific description of the preparation method is the same as that mentioned in the first aspect, and is not repeated here.

The preparation method comprises the steps of reacting 3, 9-dioxa [5.5] spiro undecane, a halogenating agent and a catalyst to obtain a coupling agent 1, 5-dihalogen-3, 3-di (2-haloethyl) pentane, then polymerizing styrene, 1, 3-butadiene and isoprene serving as reaction monomers in different combinations or independently, and finally coupling each polymer by adopting the 1, 5-dihalogen-3, 3-di (2-haloethyl) pentane coupling agent to prepare the ternary four-hetero-arm star-shaped brominated grafting agent. On one hand, the brominated grafting agent prepared by the method has high mess. On the other hand, the free radical bromine addition reaction is realized by adopting a brominating agent and a brominating initiator in the process, so that the brominated grafting agent with high bromine content and high stability is prepared by avoiding the generation of hydrogen bromide and avoiding bromine rearrangement, and the unsaturation degree of the brominated grafting agent is reduced.

In a third aspect, the present invention provides a brominated butyl rubber obtained by polymerizing the brominated grafting agent of the first or second aspect with a system comprising isobutylene and isoprene;

The mass ratio of the brominated grafting agent to the isobutene to the isoprene is (8-12): (85-90): (2-3).

The brominated butyl rubber obtained by modified grafting according to the proportion of the raw materials has excellent vulcanization processability, mixing effect, mechanical property, air tightness and aging resistance because the brominated grafting agent has the characteristics of high stability, high disorder degree and high bromine content.

The present invention is not limited to a specific graft modification method.

In one embodiment, to better adapt the aforementioned brominated grafting agent, the brominated butyl rubber is prepared by a process comprising the following steps:

adding a first diluent, isobutene and isoprene into a solution system of a brominated grafting agent at the temperature of-90 to-80 ℃, and then cooling to the temperature of-100 to-90 ℃ to obtain a first system;

The order of preparation of the first system and the second system is not particularly limited.

The invention is not limited to the dissolution of the brominated grafting agent, for example, the ratio of the volume of the brominated grafting agent added to the diluent to the volume of the solvent is 7-3:3-7, and stirring for 60-80 min until the brominated grafting agent is dissolved. Wherein the solvent is selected from linear alkane, arene and cycloparaffin, and can be selected from one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene, preferably hexane. The diluent is selected from halogenated alkanes, wherein halogen atoms in the halogenated alkanes can be chlorine, bromine or fluorine, and the number of carbon atoms in the halogenated alkanes is C1-C4, for example, one selected from chloromethane, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, monofluoromethane, difluoromethane, tetrafluoroethane, carbon hexafluoride and fluorobutane, and dichloromethane is preferred.

Further, the mass ratio of the reaction main body, the first diluent, the second diluent and the co-initiator is 1: (1-2): (0.1-0.2): (0.002-0.005); the mass of the reaction body is the total mass of the brominated grafting agent, isobutene and isoprene. It should be noted that isobutylene and isoprene herein refer to raw materials for polymerization to prepare butyl rubber.

In addition, termination of the reaction may be achieved by addition of a terminator. The terminator is one or more selected from methanol, ethanol and butanol, and the mass ratio of the terminator to the reaction main body is (0.04-0.08): 1. after the reaction is terminated, the reaction system is coagulated, washed and dried to obtain the brominated butyl rubber of the present invention.

In the above preparation process, the first diluent and the second diluent are each independently selected from one of methane chloride, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloropropane, heptachloropropane, methane fluoride, difluoromethane, tetrafluoroethane, carbon hexafluoride, and fluorobutane, preferably dichloromethane.

The co-initiator is a combination of an alkyl aluminum halide and a protic acid. The alkyl aluminum halide is at least one selected from diethyl aluminum chloride, diisobutyl aluminum chloride, methyl aluminum dichloride, aluminum sesquioxide, n-propyl aluminum dichloride, isopropyl aluminum dichloride, dimethyl aluminum chloride and ethyl aluminum chloride, preferably aluminum sesquioxide. The protonic acid is selected from HCl, HF, HBr, H ₂ SO ₄ 、H ₂ CO ₃ 、H ₃ PO ₄ And HNO ₃ Preferably HCl. Wherein the total addition amount of the co-initiator is 0.1-3.0% of the mass of the main reaction body, and the molar ratio of the protonic acid to the alkyl aluminum halide is 0.05:1-0.2:1.

In a fourth aspect, the present invention provides a rubber article processed from the brominated butyl rubber of the third aspect.

The rubber product has the characteristics of excellent ageing resistance, mixing effect, air tightness and mechanical property.

The brominated grafting agent and the brominated butyl rubber of the present invention are described in detail below by way of specific examples.

The specific sources of part of raw materials in the following preparation process are as follows:

other reagents are commercial industrial products

Example 1

The preparation method of the brominated grafting agent comprises the following steps:

1) In a 4L stainless steel polymerizer with a jacket, argon is introduced for 2 times, 500g of deionized water, 50g of 3, 9-dioxy [5.5 ] are sequentially added into the polymerizer]Spirocyclic undecane, 350g liquid bromine, 5g HCl and CH ₃ OH Mixed aqueous solution (molar concentration of HCl 0.1mol/L, CH ₃ OH molar concentration is 0.3 mol/L), heating to 60 ℃ for reaction for 1h, adding 100g of 10wt% NaOH aqueous solution for stopping reaction, finally adding 1000g of chloromethane for extraction, and then separating, washing and drying to obtain the coupling agent 1, 5-dibromo-3, 3-di (2-bromoethyl) pentane A (yield 90%).

2) A, in a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 2 times, sequentially adding 1000g of hexane and 100g,THF1.0g,18.5mmo1 n-butyllithium isoprene into the reaction kettle A, heating to 40 ℃ for reaction for 20min, sequentially adding 200g of 1, 3-butadiene and 1.0g of THF into the reaction kettle A, and heating to 50 ℃ for reaction for 40min to form a first block system;

then sequentially adding 400g of N-bromophthalodiamide and 2.0g of tertiary dodecyl mercaptan into the first block system, heating to 70 ℃, and adding 0.9g of DTBP for reaction for 3.0h to obtain a first bromination system;

B. in a 15L stainless steel reaction kettle B, introducing argon to replace a system for 2 times, sequentially adding 1000g of hexane, 100g of 1, 3-butadiene, 1.0g of THF and 20.5 mmol 1 of n-butyllithium, heating to 40 ℃ for reaction for 30min, then adding 200g of styrene into the reaction kettle B, and heating to 50 ℃ for reaction for 50min to form a second block system;

sequentially adding 200g of N-bromophthalodiamide and 1.0g of tertiary dodecyl mercaptan into the second block system, heating to 70 ℃, and adding 0.5g of DTBP for reacting for 2.0h to obtain a second bromination system;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 2 times, sequentially adding 1000g of hexane, 200g of isoprene, 1.0g of THF and 19.2 mmol 1 of n-butyllithium, heating to 40 ℃ for reaction for 50min, sequentially adding 200g of styrene and 1.0g of THF into the reaction kettle C, and heating to 50 ℃ for reaction for 40min to form a third block system;

Sequentially adding 200g of N-bromophthalodiamide and 1.0g of tertiary dodecyl mercaptan into the third block system, heating to 70 ℃, and adding 0.6g of DTBP for reaction for 3.0h to obtain a third bromination system;

D. in a 15L stainless steel reaction kettle D, introducing argon to replace the system for 2 times, sequentially adding 1000g of hexane, 200g of styrene and 1.0g of THF, heating to 60 ℃, and then adding 12.5 mmol 1 of n-butyllithium to react for 30min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 80 ℃, adding 160mmo1, 5-dibromo-3, 3-di (2-bromoethyl) pentane A for coupling reaction, adding 10.0g of 1, 3-butadiene for end-capping activation after 140min of reaction, reacting for 20min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent A of the embodiment.

The brominated butyl rubber of this example is prepared according to the following preparation method:

1) In A4L stainless steel reaction kettle with a jacket, introducing nitrogen for 3 times for replacement, adding 350g of methyl chloride, 150g of cyclohexane and 40g of brominated grafting agent A into the reaction kettle, and stirring and dissolving for 60min until the grafting agent is completely dissolved; then cooling to-80 ℃, sequentially adding 500g of dichloromethane, 450g of isobutene and 10g of isoprene, stirring and mixing until the system temperature is reduced to-90 ℃ to obtain a first system;

2) 50g of methylene dichloride, 1.26g of aluminum sesquichloride and 0.022g of HCl are mixed and aged for 30min at the temperature of minus 85 ℃, an aging system is added into the first system, after stirring and reacting for 6.0h, finally 20g of methanol is added, discharging is performed, coagulation is performed, washing is performed, and drying is performed, so that the brominated butyl rubber A of the embodiment is obtained.

Example 2

1) A, in a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 2 times, sequentially adding 1200g of hexane and 120g,THF 1.5g,20.5mmo1 n-butyllithium isoprene into the reaction kettle A, heating to 42 ℃ for reaction for 22min, sequentially adding 220g of 1, 3-butadiene and 1.3g of THF into the reaction kettle A, and heating to 52 ℃ for reaction for 42min to form a first block system;

then 410g of N-bromo-o-phthalimide and 2.5g of tertiary dodecyl mercaptan are sequentially added into the first block system, the temperature is raised to 72 ℃, 1.3g of DTBP is added for reaction for 3.1h, and a first bromination system is obtained;

B. in a 15L stainless steel reaction kettle B, introducing argon to replace a system for 2 times, sequentially adding 1200g of hexane, 120g of 1, 3-butadiene, 1.3g of THF and 23.5 mmol 1 of n-butyllithium, heating to 42 ℃ to react for 30min, then adding 220g of styrene into the reaction kettle B, and heating to 51 ℃ to react for 52min to form a second block system;

220g of N-bromo-o-xylylenediamine and 1.4g of tertiary dodecyl mercaptan are sequentially added into the second block system, the temperature is raised to 72 ℃, and 0.9g of DTBP is added for reaction for 2.2 hours, so that a second bromination system is obtained;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 2 times, sequentially adding 1200g of hexane, 220g of isoprene, 1.3g of THF and 21.2 mmol 1 of n-butyllithium, heating to 42 ℃ for reaction for 52min, sequentially adding 220g of styrene and 1.5g of THF into the reaction kettle C, and heating to 52 ℃ for reaction for 42min to form a third block system;

220g of N-bromo-o-xylylenediamine and 1.5g of tertiary dodecyl mercaptan are sequentially added into the third block system, the temperature is raised to 72 ℃, and 0.8g of DTBP is added for reaction for 3.2 hours, so that a third bromination system is obtained;

D. in a 15L stainless steel reaction kettle D, introducing argon to replace the system for 2 times, sequentially adding 1200g of hexane, 220g of styrene and 1.5g of THF, heating to 62 ℃, and then adding 15.5 mmol 1 of n-butyllithium to react for 32min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 82 ℃, adding 190mmo1, 5-dibromo-3, 3-di (2-bromoethyl) pentane A for coupling reaction, adding 15.0g of 1, 3-butadiene for end-capping activation after 145min of reaction, reacting for 32min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent B of the embodiment.

The preparation method of the brominated butyl rubber comprises the following steps:

1) Introducing nitrogen into a 4L stainless steel reaction kettle with a jacket for replacement for 3 times, adding 300g of dichloromethane, 200g of cyclohexane and 43g of brominated grafting agent B into the reaction kettle, stirring and dissolving for 64min until the grafting agent is completely dissolved, then cooling to the temperature of minus 82 ℃, sequentially adding 600g of dichloromethane, 446g of isobutene and 11g of isoprene, stirring and mixing until the system temperature is reduced to minus 92 ℃ to obtain a first system;

2) 60g of methylene dichloride, 1.45g of aluminum sesquichloride and 0.035g of HCl are mixed and aged for 32min at the temperature of minus 87 ℃, an aging system is added into a first system to be stirred and reacted for 6.3h, finally 22g of methanol is added, and then the brominated butyl rubber B of the embodiment is obtained after discharging, condensing, washing and drying.

Example 3

1) In a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 2 times, sequentially adding 1400g of hexane, 140g of isoprene, 2.3g of THF and 24.5 mmol 1 of n-butyllithium into the reaction kettle A, heating to 44 ℃ for reaction for 24min, sequentially adding 240g of 1, 3-butadiene and 2.3g of THF into the reaction kettle A, and heating to 54 ℃ for reaction for 44min to form a first block system;

Sequentially adding 450g of N-bromo-o-xylylenediamine and 3.2g of tertiary dodecyl mercaptan into the first block system, heating to 74 ℃, and adding 2.2g of DTBP for reaction for 3.3 hours to obtain a first bromination system;

B. in a 15L stainless steel reaction kettle B, introducing argon to replace a system for 3 times, sequentially adding 1400g of hexane, 140g of 1, 3-butadiene, 1.7g of THF and 26.5 mmol of 1-n-butyllithium, heating to 44 ℃ for reaction for 34min, then adding 240g of styrene into the reaction kettle B, heating to 53 ℃ for reaction for 54min, and forming a second block system;

sequentially adding 240g of N-bromophthalodiamide and 1.8g of tertiary dodecyl mercaptan into the second block system, heating to 74 ℃, and adding 1.2g of DTBP to react for 2.4 hours to obtain a second bromination system;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 3 times, sequentially adding 1400g of hexane, 240g of isoprene, 1.6g of THF and 23.2 mmol 1 of n-butyllithium, heating to 54 ℃ for reaction for 42min, sequentially adding 240g of styrene and 1.8g of THF into the reaction kettle C, and heating to 54 ℃ for reaction for 42min to form a third block system;

240g of N-bromo-o-xylylenediamine and 1.9g of tertiary dodecyl mercaptan are sequentially added into the third block system, the temperature is raised to 74 ℃, 1.3g of DTBP is added for reaction for 3.4 hours, and a third bromination system is obtained;

D. In a 15L stainless steel reaction kettle D, introducing argon to replace the system for 3 times, sequentially adding 1400g of hexane, 240g of styrene and 1.8g of THF, heating to 64 ℃, and then adding 18.5 mmol 1 of n-butyllithium to react for 34min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 82 ℃, adding 240mmo of 1, 5-dibromo-3, 3-di (2-bromoethyl) pentane A for coupling reaction, adding 20.0g of 1, 3-butadiene for end-capping activation after 149min of reaction, reacting for 24min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent C of the embodiment.

1) Introducing nitrogen into a 4L stainless steel reaction kettle with a jacket for replacement for 4 times, adding 480g of methylene dichloride, 120g of cyclohexane and 50g of brominated grafting agent C into the reaction kettle, stirring and dissolving for 69min until the grafting agent is completely dissolved, then cooling to-85 ℃, sequentially adding 700g of methylene dichloride, 438g of isobutene and 12g of isoprene, stirring and mixing until the system temperature is reduced to-94 ℃ to obtain a first system;

2) 70g of methylene dichloride, 1.89g of aluminum sesquichloride and 0.046g of HCl are mixed and aged for 34min at the temperature of minus 90 ℃, an aging system is added into a first system to be stirred and reacted for 6.8h, and finally 24g of methanol is added, and then the brominated butyl rubber C of the embodiment is obtained after discharging, condensing, washing and drying.

Example 4

1) In a 4L stainless steel polymerizer with a jacket, argon is introduced for 2 times, 1000g of deionized water, 150g of 3, 9-dioxy [5.5 ] are sequentially added into the polymerizer]Spirocyclic undecane, 450g liquid bromine, 25g HCl and CH ₃ OH Mixed aqueous solution (molar concentration of HCl 0.9mol/L, CH ₃ OH molar concentration is 0.7 mol/L), heating to 80 ℃ for reaction for 3 hours, adding 200g of 20wt% NaOH aqueous solution to terminate the reaction, finally adding 1500g of chloromethane for extraction, and then separating, washing and drying to obtain the coupling agent 1, 5-dibromo-3, 3-di (2-bromoethyl) pentane D (yield 95%).

2) A, in a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 3 times, sequentially adding 1600g of hexane, 160g of isoprene, 2.5g of THF and 27.5 mmol of n-butyllithium into the reaction kettle A, heating to 46 ℃ for reaction for 27.5min, sequentially adding 260g of 1, 3-butadiene and 2.5g of THF into the reaction kettle A, and heating to 56 ℃ for reaction for 46min to form a first block system;

then 460g of N-bromo-o-xylylenediamine and 3.4g of tertiary dodecyl mercaptan are sequentially added into the first block system, the temperature is raised to 76 ℃, 2.4g of DTBP is added for reaction for 3.5 hours, and a first bromination system is obtained;

B. In a 15L stainless steel reaction kettle B, introducing argon to replace the system for 3 times, sequentially adding 160 g of hexane, 150g of 1, 3-butadiene, 1.9g of THF and 28.5 mmol of n-butyllithium, heating to 46 ℃ to react for 36min, then adding 260g of styrene into the reaction kettle B, heating to 55 ℃ to react for 56min, and forming a second block system;

sequentially adding 260g of N-bromo-o-xylylenediamine and 2.0g of tertiary dodecyl mercaptan into a second block system, heating to 75 ℃, and adding 1.6g of DTBP for reacting for 2.6 hours to obtain a second bromination system;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 3 times, sequentially adding 1600g of hexane, 260g of isoprene, 1.9g of THF and 25.2 mmol 1 of n-butyllithium, heating to 46 ℃ for reaction for 56min, then sequentially adding 260g of styrene and 2.2g of THF into the reaction kettle C, heating to 56 ℃ for reaction for 45min, and forming a third block system;

sequentially adding 260g of N-bromo-o-xylylenediamine and 2.2g of tertiary dodecyl mercaptan into a third block system, heating to 76 ℃, and adding 1.9g of DTBP for reaction for 3.6 hours to obtain a third bromination system;

D. in a 15L stainless steel reaction kettle D, introducing argon to replace the system for 3 times, sequentially adding 1600g of hexane, 260g of styrene and 2.1g of THF, heating to 66 ℃, and then adding 20.5 mmol 1 of n-butyllithium to react for 36min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 85 ℃, adding 300mmo1, 5-dibromo-3, 3-di (2-bromoethyl) pentane D for coupling reaction, adding 28.0g of 1, 3-butadiene for end-capping activation after 152min of reaction, reacting for 26min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent D of the embodiment.

1) Adding 400g of methylene dichloride, 200g of cyclohexane and 53g of brominated grafting agent D into a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for replacement for 4 times, stirring and dissolving for 72min until the grafting agent is completely dissolved, then cooling to the temperature of-86 ℃, sequentially adding 800g of methylene dichloride, 434g of isobutene and 13g of isoprene, stirring and mixing until the system temperature is reduced to the temperature of-96 ℃ to obtain a first system;

2) 80g of methylene dichloride, 2.01g of aluminum sesquichloride and 0.056g of HCl are mixed and aged for 36min at the temperature of minus 91 ℃, an aging system is added into a first system to be stirred and reacted for 7.3h, and finally 26g of methanol is added, and then the brominated butyl rubber D of the embodiment is obtained after discharging, condensing, washing and drying.

Example 5

1) A, in a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 4 times, sequentially adding 1800g of hexane, 180g of isoprene, 2.7g of THF and 28.5 mmol of n-butyllithium into the reaction kettle A, heating to 48 ℃ for reaction for 28min, sequentially adding 280g of 1, 3-butadiene and 280g of THF into the reaction kettle A, and heating to 58 ℃ for reaction for 48min to form a first block system;

480g of N-bromophthalodiamide and 3.8g of tertiary dodecyl mercaptan are sequentially added into the first block system, the temperature is raised to 78 ℃, 2.6g of DTBP is added for reaction for 3.8 hours, and a first bromination system is obtained;

B. in a 15L stainless steel reaction kettle B, introducing argon to replace a system for 4 times, sequentially adding 180g of hexane, 180g of 1, 3-butadiene, 2.3g of THF and 30.5 mmol 1 of n-butyllithium, heating to 48 ℃ to react for 38min, then adding 280g of styrene into the reaction kettle B, and heating to 48 ℃ to react for 58min to form a second block system;

then 280g of N-bromo-o-xylylenediamine and 2.5g of tertiary dodecyl mercaptan are sequentially added into the second block system, the temperature is raised to 78 ℃, 1.9g of DTBP is added for reaction for 2.8 hours, and a second bromination system is obtained;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 4 times, sequentially adding 1800g of hexane, 280g of isoprene, 2.3g of THF and 26.3mmo1 of n-butyllithium, heating to 48 ℃ for reaction for 58min, then sequentially adding 280g of styrene and 2.7g of THF into the reaction kettle C, heating to 58 ℃ for reaction for 48min, and forming a third block system;

Then 280g of N-bromo-o-xylylenediamine and 2.6g of tertiary dodecyl mercaptan are sequentially added into the third block system, the temperature is raised to 78 ℃, and 2.1g of DTBP is added for reaction for 3.8 hours, so as to obtain a third bromination system;

D. in a 15L stainless steel reaction kettle D, introducing argon to replace the system for 4 times, sequentially adding 1800g of hexane, 280g of styrene and 2.7g of THF, heating to 68 ℃, and then adding 22.5 mmol 1 of n-butyllithium to react for 38min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 87 ℃, adding 350mmo1, 5-dibromo-3, 3-di (2-bromoethyl) pentane D for coupling reaction, adding 35.0g of 1, 3-butadiene for end-capping activation after 156min of reaction, reacting for 28min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent E of the embodiment.

1) Introducing nitrogen into a 4L stainless steel reaction kettle with a jacket for replacement for 5 times, adding 300g of dichloromethane, 300g of cyclohexane and 56g of brominated grafting agent E into the polymerization kettle, stirring and dissolving for 75min until the grafting agent is completely dissolved, then cooling to-88 ℃, sequentially adding 900g of dichloromethane, 430g of isobutene and 14g of isoprene, stirring and mixing until the system temperature is reduced to-98 ℃ to obtain a first system;

2) 90g of methylene dichloride, 2.26g of aluminum sesquichloride and 0.063g of HCl are mixed and aged for 38min at the temperature of minus 93 ℃, an aging system is added into a first system to be stirred and reacted for 7.6h, and finally 28g of methanol is added, and then the brominated butyl rubber E of the embodiment is obtained after discharging, condensing, washing and drying.

Example 6

1) A, in a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 4 times, sequentially adding 2000g of hexane and 200g,THF 3g,30.5mmo1 n-butyllithium isoprene into the reaction kettle A, heating to 50 ℃ for reaction for 30min, sequentially adding 300g of 1, 3-butadiene and 300g of THF3g into the reaction kettle A, and heating to 60 ℃ for reaction for 50min to form a first block system;

then adding 500g of N-bromo-o-xylylenediamine and 4g of tertiary dodecyl mercaptan into the first block system in sequence, heating to 80 ℃, and adding 2.9g of DTBP for reaction for 4 hours to obtain a first bromination system;

B. in a 15L stainless steel reaction kettle B, introducing argon to replace a system for 4 times, sequentially adding 2000g of hexane, 200g,THF 3g,32.5mmo1 n-butyllithium of 1, 3-butadiene, heating to 50 ℃ for reaction for 40min, then adding 300g of styrene into the reaction kettle B, heating to 60 ℃ for reaction for 60min, and forming a second block system;

Sequentially adding 300g of N-bromophthalodiamide and 3g of tertiary dodecyl mercaptan into a second block system, heating to 80 ℃, and adding 2.4g of DTBP for reaction for 3 hours to obtain a second bromination system;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 4 times, sequentially adding 2000g of hexane and 300g,THF 3g,28.5mmo1 n-butyllithium isoprene, heating to 50 ℃ for reaction for 60min, sequentially adding 300g of styrene and 3g of THF into the reaction kettle C, and heating to 60 ℃ for reaction for 50min to form a third block system;

sequentially adding 300g of N-bromophthalodiamide and 3g of tertiary dodecyl mercaptan into a third block system, heating to 80 ℃, and adding 2.6g of DTBP for reaction for 4 hours to obtain a third bromination system;

D. in a 15L stainless steel reaction kettle D, introducing argon to replace the system for 4 times, sequentially adding 2000g of hexane, 300g of styrene and 3g of THF, heating to 70 ℃, and then adding 23.5 mmol 1 of n-butyllithium to react for 40min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 90 ℃, adding 400mmo1, 5-dibromo-3, 3-di (2-bromoethyl) pentane D for coupling reaction, adding 40.0g of 1, 3-butadiene for end-capping activation after 160min of reaction, reacting for 30min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent F of the embodiment.

1) Introducing nitrogen into a 4L stainless steel reaction kettle with a jacket for replacement for 5 times, adding 300g of dichloromethane, 700g of cyclohexane and 60g of brominated grafting agent F into the polymerization kettle, stirring and dissolving for 80min until the grafting agent is completely dissolved, then cooling to-90 ℃, sequentially adding 1000g of dichloromethane, 425g of isobutene and 15g of isoprene, stirring and mixing until the system temperature is reduced to-100 ℃ to obtain a first system;

2) 100g of methylene dichloride, 2.53g of aluminum sesquichloride and 0.078g of HCl are mixed and aged for 40min at the temperature of minus 95 ℃, an aging system is added into a first system to be stirred and reacted for 8h, 30g of methanol is finally added, and then the brominated butyl rubber F of the embodiment is obtained after discharging, condensing, washing and drying.

Example 7

1) A, in a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 2 times, sequentially adding 1000g of hexane and 100g,THF 1.0g,17.5mmo1 n-butyllithium isoprene into the reaction kettle A, heating to 40 ℃ for reaction for 20min, sequentially adding 190g of 1, 3-butadiene and 1.0g of THF into the reaction kettle A, and heating to 50 ℃ for reaction for 40min to form a first block system;

B. in a 15L stainless steel reaction kettle B, introducing argon to replace a system for 2 times, sequentially adding 1000g of hexane, 90g of 1, 3-butadiene, 1.0g of THF and 18.5 mmol 1 of n-butyllithium, heating to 40 ℃ for reaction for 30min, then adding 190g of styrene into the reaction kettle B, and heating to 50 ℃ for reaction for 50min to form a second block system;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 2 times, sequentially adding 1000g of hexane, 200g of isoprene, 1.0g of THF and 18.5 mmol 1 of n-butyllithium, heating to 40 ℃ for reaction for 50min, sequentially adding 190g of styrene and 1.0g of THF into the reaction kettle C, and heating to 50 ℃ for reaction for 40min to form a third block system;

D. In a 15L stainless steel reaction kettle D, introducing argon to replace the system for 2 times, sequentially adding 1000g of hexane, 200g of styrene and 1.0g of THF, heating to 60 ℃, and then adding 11.5 mmol 1 of n-butyllithium to react for 30min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 80 ℃, adding 160mmo1, 5-dibromo-3, 3-di (2-bromoethyl) pentane D for coupling reaction, adding 10.0G of 1, 3-butadiene for end-capping activation after 140min of reaction, reacting for 20min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent G of the embodiment.

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for 3 times for replacement, adding 350G of methyl chloride, 150G of cyclohexane and 40G of brominated grafting agent into the reaction kettle, stirring and dissolving for 60min until the grafting agent is completely dissolved; then cooling to-80 ℃, sequentially adding 500g of dichloromethane, 450g of isobutene and 10g of isoprene, stirring and mixing until the system temperature is reduced to-90 ℃ to obtain a first system;

2) 50G of methylene dichloride, 1.26G of aluminum sesquichloride and 0.022G of HCl are mixed and aged for 30min at the temperature of minus 85 ℃, an aging system is added into the first system, after stirring and reacting for 6.0h, finally 20G of methanol is added, discharging is performed, coagulation is performed, washing is performed, and drying is performed, so that the brominated butyl rubber G of the embodiment is obtained.

Example 8

1) A, in a 15L stainless steel reaction kettle A with a jacket, introducing argon for replacement for 4 times, sequentially adding 2000g of hexane and 200g,THF 3g,32.5mmo1 n-butyllithium isoprene into the reaction kettle A, heating to 50 ℃ for reaction for 30min, sequentially adding 300g of 1, 3-butadiene and 300g of THF3g into the reaction kettle A, and heating to 60 ℃ for reaction for 50min to form a first block system;

B. in a 15L stainless steel reaction kettle B, introducing argon to replace a system for 4 times, sequentially adding 2000g of hexane, 210g,THF 3g,33.5mmo1 n-butyllithium of 1, 3-butadiene, heating to 50 ℃ for reaction for 40min, then adding 300g of styrene into the reaction kettle B, heating to 60 ℃ for reaction for 60min, and forming a second block system;

C. in a 15L stainless steel reaction kettle C, introducing argon to replace a system for 4 times, sequentially adding 2000g of hexane and 320g,THF 3g,30.5mmo1 n-butyllithium isoprene, heating to 50 ℃ for reaction for 60min, sequentially adding 300g of styrene and 3g of THF into the reaction kettle C, and heating to 60 ℃ for reaction for 50min to form a third block system;

D. in a 15L stainless steel reaction kettle D, introducing argon to replace the system for 4 times, sequentially adding 2000g of hexane, 300g of styrene and 3g of THF, heating to 70 ℃, and then adding 25.5 mmol 1 of n-butyllithium to react for 40min to form a fourth block system;

3) Adding a second bromination system, a third bromination system and a fourth block system into a first bromination system, heating to 90 ℃, adding 400mmo1, 5-dibromo-3, 3-di (2-bromoethyl) pentane D for coupling reaction, adding 40.0g of 1, 3-butadiene for end-capping activation after 160min of reaction, reacting for 30min until no free monomer exists, and carrying out wet condensation and drying on the reaction solution to obtain the brominated grafting agent H of the embodiment.

1) Introducing nitrogen into a 4L stainless steel reaction kettle with a jacket for replacement for 5 times, adding 300g of dichloromethane, 700g of cyclohexane and 60g of brominated grafting agent H into the polymerization kettle, stirring and dissolving for 80min until the grafting agent is completely dissolved, then cooling to-90 ℃, sequentially adding 1000g of dichloromethane, 425g of isobutene and 15g of isoprene, stirring and mixing until the system temperature is reduced to-100 ℃ to obtain a first system;

2) 100g of methylene dichloride, 2.53g of aluminum sesquichloride and 0.078g of HCl are mixed and aged for 40min at the temperature of minus 95 ℃, an aging system is added into a first system to be stirred and reacted for 8H, 30g of methanol is finally added, and then the mixture is discharged and coagulated, washed and dried to obtain the brominated butyl rubber H of the embodiment.

Comparative example 1

The preparation of the brominated grafting agent a of this comparative example was essentially identical to that of example 1, except that HBr was used in place of N-bromophthalamide in example 1.

The preparation of the brominated butyl rubber a of this comparative example was substantially identical to that of example 1, except that the brominated grafting agent a of example 1 was replaced with a brominated grafting agent a.

Comparative example 2

The preparation method of the brominated grafting agent b of this comparative example was substantially the same as in example 2, except that the amount of N-bromophthalamide added in the reaction vessel A was 100g.

The preparation of the brominated butyl rubber B of this comparative example was substantially identical to that of example 2, except that the brominated grafting agent B of example 2 was replaced with a brominated grafting agent B.

Comparative example 3

The preparation of brominated butyl rubber C of this comparative example was substantially identical to that of example 3, except that brominated grafting agent C was added in an amount of 10g.

Comparative example 4

The preparation of brominated grafting agent D of this comparative example was essentially identical to that of example 4, except that the 1, 5-dibromo-3, 3-bis (2-bromoethyl) pentane D coupling agent of example 4 was replaced with a silicon tetrachloride coupling agent.

The preparation of the brominated butyl rubber D of this comparative example was substantially identical to that of example 4, except that the brominated grafting agent D added was substituted for the brominated grafting agent D of example 4.

Comparative example 5

The preparation of the brominated grafting agent e of this comparative example was substantially identical to example 5, except that the preparation of the fourth block system of step D was not included, and the second and third bromination systems were added to the first bromination system to carry out the coupling reaction.

The preparation of brominated butyl rubber E of this comparative example is substantially identical to that of example 5, except that brominated grafting agent E of example 5 is replaced with brominated grafting agent E.

Comparative example 6

The preparation of the brominated grafting agent f of this comparative example was essentially identical to that of example 6, except that the blocking activation was carried out without the addition of 1, 3-butadiene in step 3).

The preparation of the brominated butyl rubber F of this comparative example was substantially identical to that of example 6, except that the brominated grafting agent F of example 6 was replaced with a brominated grafting agent F.

Test examples

1. The following parameters were examined in the brominated grafting agent in the above examples and comparative examples, and the specific results are shown in Table 1.

The mass percent of bromine is as follows: the detection method comprises the following steps: 10mg of the sample is weighed, and the sample is thermally degraded in a nitrogen atmosphere with the flow rate of 50mL/min by adopting a Q600 type TG/DTG thermogravimetric analyzer and the heating rate of 10 ℃/min. The first stage of thermal degradation is to remove bromine from a bromine-containing unit of a sample to form HBr, and then reversely calculate the bromine content (X) in the sample by the percentage of the removed HBr, wherein the calculation formula is as follows:

wherein Y: the percentage of the sample at 220 ℃;79.904: bromine element relative atomic mass; 1.008: hydrogen element relative to atomic mass.

Molecular weight and distribution thereof: measured by using a 2414 Gel Permeation Chromatograph (GPC) manufactured by Waters corporation of the United states. The polystyrene standard sample is used as a calibration curve, the mobile phase is tetrahydrofuran, the column temperature is 40 ℃, the sample concentration is 1mg/ml, the sample injection amount is 50 mu L, the elution time is 40min, and the flow rate is 1 ml.min ^-1 。

TABLE 1

	Bromine mass percent%	Number average molecular weight/molecular weight distribution
			Example 1	18.3％	103000/16.27
Example 2	19.4％	112000/16.58
			Example 3	20.2％	119000/16.96
Example 4	21.5％	123000/17.26
			Example 5	22.1％	127000/17.53
Example 6	22.8％	130000/17.86
			Example 7	18.1％	98000/16.15
Example 8	22.9％	138000/17.97
			Comparative example 1	13.6％	95000/14.35
Comparative example 2	15.1％	105000/15.61
			Comparative example 3	20.2％	119000/16.96
Comparative example 4	17.8％	115000/12.12
			Comparative example 5	21.5％	88000/10.13
Comparative example 6	20.9％	129000/17.63

As can be seen from Table 1, the preparation method provided by the invention can prepare the brominated grafting agent shown in the formula 1, wherein the bromine content of the brominated grafting agent is not less than 18 wt%.

2. The brominated butyl rubber in the above examples and comparative examples was sampled and tested after preparing standard samples according to the test requirements of the following relevant parameters, and the results are shown in table 2.

The mass percent of bromine is as follows: the method is the same as above.

Vulcanization characteristics: GT-M2000A rotor-free vulcanizing instrument manufactured by Taiwan high-speed rail company is adopted for testing according to GB/T16584-1996. Wherein T is ₁₀ To reflect the scorch safety window size, T ₉₀ The positive vulcanization time reflects the vulcanization speed.

Air tightness: an automatic air tightness tester is adopted to measure the air permeability number according to ISO 2782:1995, and the test gas is N ₂ The test temperature is 23 ℃, the test sample piece is an 8cm diameter circular sea piece, and the thickness is 1mm.

Determination of tensile Strength: tested according to GB/T528-2009.

Unsaturation degree: the magnetic field strength of AVANCE300 nuclear magnetic resonance apparatus of Bruker company is 9.20 Tesla, CDC1 is adopted ₃ TMS was used as an internal standard as solvent and measured at room temperature (25 ℃).

Static ozone performance: the TD-401A type thermal aging tester is adopted, and the testing method comprises the following steps: stretching 25%, ozone mass fraction 50×10 ^-8 The temperature is 40 ℃ and the time is 1000 hours.

Determination of mooney viscosity: the Mooney relaxation time was 120S as measured using a Mooney viscometer model GT-7080-S2 manufactured by Taiwan high-speed rail company according to GB/T1232.1-2000, specifically using a large rotor under 125 ℃ (1+8).

TABLE 2

As is clear from Table 2, the bromine grafting agent of the present invention contributes to achieving efficient modification of butyl rubber, and the modified brominated butyl rubber exhibits excellent vulcanization processing characteristics, kneading effect, mechanical strength, aging resistance and air tightness.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A brominated grafting agent, characterized in that the brominated grafting agent has a structure represented by formula 1:

2. The brominated grafting agent of claim 1, wherein the brominated grafting agent has a number average molecular weight of 100000 ～ 130000 and a molecular weight distribution of 16.27 to 17.86.

3. The brominated grafting agent of claim 1 or 2, wherein the brominated grafting agent is prepared by a process comprising:

4. A brominated grafting agent as claimed in claim 3, characterized in that,

the mass ratio of the 3, 9-dioxo [5.5] spiro undecane to the halogenating agent to the catalyst is (10-30): (70-90): (1-5); and/or the number of the groups of groups,

Wherein the brominating agent consists of the first organic brominating agent, the second organic brominating agent and the third organic brominating agent, and the mass ratio of the first organic brominating agent, the second organic brominating agent and the third organic brominating agent is (0.4-0.5): (0.2-0.3): (0.2-0.4).

5. The brominated grafting agent of claim 3 or 4, wherein the molar ratio of the coupling agent to the polymerization initiator is (2:1) - (5:1);

6. The preparation method of the brominated grafting agent is characterized by comprising the following steps:

The brominated grafting agent has a structure shown in a formula 1,

7. A brominated butyl rubber obtained by polymerizing a brominated grafting agent as defined in any one of claims 1 to 5 or a brominated grafting agent prepared as defined in claim 6 with a system comprising isobutylene and isoprene;

8. The brominated butyl rubber of claim 7, wherein the brominated butyl rubber is prepared by a process comprising:

9. The brominated butyl rubber of claim 8 wherein the mass ratio of the reaction mass, the first diluent, the second diluent, and the co-initiator is 1: (1-2): (0.1-0.2): (0.002-0.005);

10. A rubber article, wherein said rubber article is processed from the brominated butyl rubber of any one of claims 7-9.