CN116355155A

CN116355155A - Brominated grafting agent and preparation method and application thereof

Info

Publication number: CN116355155A
Application number: CN202111631180.XA
Authority: CN
Inventors: 徐典宏; 赵志超; 孟令坤; 魏绪玲; 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 homopolymerized block of styrene, E is a homopolymerized block of 1, 3-butadiene which is dibrominated, A is a homopolymerized block of isoprene which is dibrominated, D is a 1, 3-butadiene homopolymer with a number average molecular weight not higher than 1000, and m is more than or equal to 1; in the brominated grafting agent, the mass percentage of bromine element is 14-20%. The brominated grafting agent can be used as a modifier for the butyl rubber to modify the butyl rubber into brominated butyl rubber, and is beneficial to obviously improving the properties of the brominated butyl rubber including mechanical strength, vulcanization processability and the like, thereby widening the application range of the butyl rubber.

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, so that the molecular structure determines the unavoidable problems of poor ozone aging resistance, poor mechanical strength, long vulcanization scorching time, low vulcanization speed and the like, and the processability of the butyl rubber cannot meet the processing requirements and application scenes of gradual diversification, thus becoming 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 the para-butyl rubber, can modify the butyl rubber into the brominated butyl rubber, and can obviously improve the properties of the brominated butyl rubber including vulcanization processability, air tightness, tensile strength 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.

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 degree, air permeability, shorter vulcanization scorch time and positive vulcanization time, longer static ozone property break time and stronger tensile strength.

The invention also provides a rubber product which is obtained by processing the brominated butyl rubber and has excellent performance in vulcanization processing characteristics, air tightness, tensile strength 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, E is a dibromo 1, 3-butadiene homo-block, A is a dibromo isoprene homo-block, D is a 1, 3-butadiene homopolymer with a number average molecular weight not higher than 1000, and m is not less than 1;

in the brominated grafting agent, the mass percentage of bromine element is 14-20%.

The brominated grafting agent as described above, wherein the number average molecular weight of the brominated grafting agent is 30000 to 50000 and the molecular weight distribution is 2.24 to 3.15.

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

Adding a polymerization initiator into the first raw material system at 40-50 ℃ and then reacting for 30-50 min to obtain a first block system;

adding a second raw material system into the first block system, and reacting at 50-60 ℃ for 40-60 min to obtain a second block system;

adding a third raw material system into the second block system, and reacting at 60-70 ℃ for 60-80 min to obtain a third block system;

adding an organic brominating agent and a bromination molecular weight regulator into the third block system, heating to 70-80 ℃, adding an organic bromination initiator, and reacting for 3-5 h to obtain a bromination system; then adding an activated end capping reagent into the bromination system to react for 20-30 min to obtain the bromination grafting reagent;

the first raw material system comprises a first monomer and a first structure regulator, the second raw material system comprises isoprene and a second structure regulator, the third raw material system comprises styrene and a third structure regulator, and the first monomer and the activating end capping agent are both 1, 3-butadiene.

The brominated grafting agent comprises the following components in percentage by mass: (0.2-0.3): (0.001-0.003); and/or the number of the groups of groups,

The mass ratio of the total mass of the monomers to the isoprene and the second structure regulator is 1: (0.3-0.4): (0.001-0.004); and/or the number of the groups of groups,

the mass ratio of the total mass of the monomers to the styrene and the third structure regulator is 1: (0.3-0.5): (0.003-0.005); and/or the number of the groups of groups,

the mass ratio of the total mass of the monomers to the organic brominating agent, the brominating molecular weight regulator, the organic brominating initiator and the activating end capping agent is 1: (0.9-1.1): (0.003-0.006): (0.001-0.004): (0.01-0.03);

wherein the total mass of the monomers is the total mass of the first monomer, isoprene and styrene.

The brominated grafting agent as described above, wherein the organic brominating agent is selected from one of N-bromosuccinimide, N-bromophthalimide, N '-dibromo-5, 5' -dimethylhydantoin; and/or, the organic bromination initiator is an organic peroxide.

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

the first raw material system comprises a first monomer and a first structure regulator, the second raw material system comprises isoprene and a second structure regulator, the third raw material system comprises styrene and a third structure regulator, and the first monomer and the activation end capping agent are both 1, 3-butadiene;

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

ps is a homopolymerized block of styrene, E is a homopolymerized block of 1, 3-butadiene dibrominated, a is a homopolymerized block of isoprene dibrominated, D is a 1, 3-butadiene homopolymer having a number average molecular weight of not more than 1000, and m is not less than 1;

The invention also provides a brominated butyl rubber, which is obtained by the polymerization reaction of the brominated grafting agent of any one of the above or the brominated grafting prepared by the above and a system comprising isobutene and isoprene;

The mass ratio of the brominated grafting agent to the isobutene to the isoprene is (4-8): (90-95): (1-2).

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 then adjusting the temperature to-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 and reacting for 2 to 4 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): (0.2-0.3): (0.0003 to 0.004);

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, which 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, large steric hindrance and high saturation, thereby being beneficial to improving the vulcanization processing characteristics, mechanical strength, ageing resistance and air tightness of the brominated butyl rubber.

Therefore, the rubber product processed from the brominated butyl rubber has excellent performance in vulcanization processing characteristics, mechanical strength, 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:

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 formed from three homopolymer block copolymers. Specifically, one homopolymer block is a styrene homopolymer block Ps, one homopolymer block is a dibromo isoprene homopolymer block a, and one homopolymer block is a dibromo 1, 3-butadiene homopolymer block E. Wherein 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 A 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 an activated end sealing group B, wherein the activated end sealing 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, particularly the stability of a secondary carbon atom bromine structure is excellent, the problem that the butyl rubber is hard to vulcanize due to less double bonds caused by high saturation is solved, and the vulcanization speed is improved.

In addition, from the structural point of view, the brominated grafting agent comprises a plurality of phenyl groups, and the phenyl groups have the characteristics of large steric hindrance and high rigidity, so that the problem of strength reduction of butyl rubber caused by the widening of molecular weight distribution of the butyl rubber due to branching can be avoided, and the modified brominated butyl rubber is ensured to have excellent mechanical strength.

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.

Therefore, the brominated grafting agent has the characteristics of stable bromine structure, more large steric hindrance groups and high saturation, and the brominated butyl rubber modified by the brominated grafting agent can be beneficial to improving the vulcanization processability, tensile strength, ozone aging resistance and 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 above brominated grafting agent is 30000 to 50000 and the molecular weight distribution (Mw/Mn) is 2.24 to 3.15, 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 first block system preparation step, a second block system preparation step, a third block system preparation step, a bromination system preparation step and an activation step respectively, wherein the activation step is a process of end-capping activation of the bromination system.

These five steps are described below.

The first block system of the present invention is a homo-block system of 1, 3-butadiene. Specifically, a polymerization initiator is added to a first raw material system including 1, 3-butadiene and a first structure regulator at 40 to 50 ℃ and reacted for 30 to 50 minutes, and in the reaction process, 1, 3-butadiene is homopolymerized as a monomer to obtain a homopolymerized block system of 1, 3-butadiene.

Subsequently, a second raw material system comprising isoprene and a second structure modifier is added to the first block system, and reacted at 50 to 60 ℃ for 40 to 60 minutes, during which isoprene as a monomer is homopolymerized to obtain a homopolymerized block of isoprene, and the homopolymerized block of isoprene is copolymerized with the homopolymerized block of 1, 3-butadiene in the first block system to obtain a second block system comprising a homopolymerized block of 1, 3-butadiene-a homopolymerized block of isoprene.

Then, a third raw material system comprising styrene and a third structure modifier is added to the third block system, and reacted at 60 to 70 ℃ for 60 to 80 minutes, in which process styrene as a monomer is homopolymerized to obtain a homopolymerized block of styrene, and the homopolymerized block of styrene is copolymerized with a homopolymerized block of 1, 3-butadiene-isoprene in the second block system to obtain a third block system comprising a homopolymerized block of 1, 3-butadiene-isoprene-homopolymerized block of styrene.

After preparing a third block system, adding an organic brominating agent and a brominating molecular weight regulator into the third block system, heating the mixture to 70-80 ℃, adding an organic brominating initiator into the mixture to react for 3-5 hours, and enabling the organic brominating agent and the homo-polymer block of 1, 3-butadiene homo-polymer block of isoprene-homo-polymer block of styrene to generate free radical bromination addition reaction to obtain a bromination system comprising E-A-Ps.

And finally, adding an activated end capping reagent 1, 3-butadiene into the bromination system to react for 20-30 min, thus obtaining the bromination grafting agent. After the activated end capping reagent is added for reaction for 20-30 min, the reaction system is subjected to post-treatment including discharging coagulation, washing and drying to finally obtain the brominated grafting reagent.

As mentioned above, both the brominating agent and the brominating initiator employed in the preparation of the bromination system 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 the total mass of the monomers to the first monomer and the first structure-modifying agent is 1: (0.2-0.3): (0.001-0.003); and/or the number of the groups of groups,

the mass ratio of the total mass of the monomers to the organic brominating agent, the brominating molecular weight regulator, the organic brominating initiator and the activating end capping agent is 1: (0.9-1.1): (0.003-0.006): (0.001-0.004): (0.01-0.03), the economic benefit of the production process can be increased by increasing the yield of the product.

It will be appreciated that solvents are also included in the preparation process described above. Specifically, the first raw material system comprises a solvent, and further, the mass of the solvent in the first raw material system is 100% -200% of the total mass of the monomers; in addition to the organic brominating agent and the molecular weight regulator for bromination, a solvent is added into the third block system, and the mass of the solvent is 100-200% of the total mass of the monomers. The solvent is independently selected from linear alkanes, aromatic hydrocarbons and cycloalkanes, and may be specifically selected from one of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, xylene and ethylbenzene, preferably cyclohexane.

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 preparation process of the invention, the organic brominating agent is selected from one of N-bromosuccinimide, N-bromophthalimide and N, N '-dibromo-5, 5' -dimethylhydantoin, and preferably N-bromosuccinimide; and/or the organic bromination initiator is an organic peroxide. For example, the organic brominating agent is selected from one of di-t-butyl hydroperoxide (TBHP), 2, 5-dimethyl-2, 5-di-t-Butyl Peroxyhexane (BPDH), di-t-butyl peroxide (DTBP), dicumyl peroxide (DCP), preferably TBHP.

The polymerization initiator is a hydrocarbyl mono-lithium compound, i.e., RLi, wherein R is a saturated aliphatic hydrocarbon group containing 1 to 20 carbon atoms, a cycloaliphatic hydrocarbon group, an aromatic hydrocarbon group, or a complex group of the above. The first polymerization initiator, the second polymerization initiator and the third polymerization initiator are each independently selected from one of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium and dodecyllithium, preferably n-butyllithium. The amount of polymerization initiator added is determined by the molecular weight of the target brominated grafting agent, for example, the amount of butyl lithium species is calculated by the following formula.

Butyllithium molar mass (mol) =total gum mass M (g)/molecular weight M (g/mol)

Wherein, the total mass of the glue refers to the expected preparation mass of the target brominated grafting agent, and the molecular weight refers to the molecular weight of the target brominated grafting agent.

The first structure modifier, the second structure modifier and the third structure modifier are all polar organic compounds for producing a solvation effect in the polymerization reaction. The first structure modifier, the second structure modifier and the third structure modifier 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 brominated molecular weight regulator is selected from one of tertiary dodecyl mercaptan, tertiary tetradecyl mercaptan and tertiary hexadecyl mercaptan, and preferably tertiary dodecyl mercaptan.

The brominated grafting agent is an organic combination of a 1, 3-butadiene homopolymerization block, an isopentene homopolymerization block, a styrene 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, ageing resistance, air tightness and tensile strength.

The second aspect of the invention provides a preparation method of a brominated grafting agent, wherein a polymerization initiator is added into a first raw material system at 40-50 ℃ and then reacts for 30-50 min to obtain a first block system;

adding an organic brominating agent and a bromination molecular weight regulator into the third block system, heating to 70-80 ℃, adding an organic bromination initiator, and reacting for 3-5 h to obtain a bromination system;

adding an activated end capping reagent into the bromination system to react for 20-30 min to obtain the bromination grafting agent;

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 takes isoprene, styrene and 1, 3-butadiene as reaction monomers to carry out homopolymerization block copolymerization, and finally adopts an organic brominating agent to carry out free radical addition reaction to prepare the brominated grafting agent. On one hand, the brominated grafting agent prepared by the method contains a large number of benzene ring structures, which is beneficial to improving the tensile strength of butyl rubber. On the other hand, in the process, the free radical bromine addition reaction is realized by adopting an organic brominating agent and an organic brominating initiator, 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 brominated butyl rubber obtained by modified grafting according to the proportion of the raw materials has excellent vulcanization processability, ageing resistance, air tightness and tensile strength because the brominated grafting agent has the characteristics of high stability, high saturation, high rigidity and large steric hindrance.

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:

The invention is not limited to the dissolution mode of the brominated grafting agent, for example, the brominated grafting agent is added into a mixed solvent of which the volume ratio of the diluent to the solvent is 7:3-3:7, and stirred for 30-50 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 cyclohexane. 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 preferably chloromethane.

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 (0.04-0.07): 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 methane chloride.

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 0.2-0.7% of the mass of the main reaction body, and the molar ratio of the protonic acid to the alkyl aluminum halide is 0.05:1-0.1:1.

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

The rubber product of the invention has the characteristics of excellent vulcanization processing characteristics, air tightness, ageing resistance and tensile strength.

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:

styrene, 1, 3-butadiene, polymer grade China petro-lan petrochemical Co Ltd

Isobutene, isoprene, polymeric grade Zhejiang Xinhui New Material Co., ltd

N-bromosuccinimide polymerization grade Jiangsu Runfeng synthetic technology Co., ltd

Di-tert-butyl hydroperoxide (TBHP), lanzhou auxiliary plant

N-butyllithium with purity of 98% Nanjing Tonglian chemical Co., ltd

Sesquiethyl aluminum chloride with purity of 98% of carbofuran technology Co., ltd

Tertiary butyl trichlorosilane with purity of 98% of Nanjing Tonglian chemical Co., ltd

Other reagents are commercial industrial products

Example 1

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

introducing argon gas into a 15L stainless steel reaction kettle with a jacket for replacement for 2 times, sequentially adding 2000g of cyclohexane, 200g of 1, 3-butadiene and 1.0g of THF into the polymerization kettle, heating to 40 ℃, and then adding 14.8mmo1 of n-butyllithium to start reaction for 30min; then adding 300g of isoprene and 1.0g of THF into a polymerization kettle, heating to 50 ℃, and reacting for 40min; then adding 300g of styrene and 3.0g of THF into a polymerization kettle, heating to 60 ℃, and reacting for 60min to obtain a third block system;

then 1000g of cyclohexane, 900g of N-bromosuccinimide and 3.0g of tertiary dodecyl mercaptan are added into the third block system, the temperature is raised to 70 ℃, and 1.0g of TBHP is added for reaction for 3.0h, so that a bromination system is obtained; and adding 10g of 1, 3-butadiene into a bromination system for end-capping activation, reacting for 20min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent A (Mn is 31000 and Mw/Mn is 2.24).

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

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for 3 times for replacement, adding 150g of chloromethane, 350g of cyclohexane and 20g of brominated grafting agent A into the polymerization kettle, stirring and dissolving for 30min until the brominated grafting agent A is completely dissolved; then cooling to-80 ℃, sequentially adding 500g of chloromethane, 475g of isobutene and 5g of isoprene, stirring and mixing until the system temperature is reduced to-90 ℃ to obtain a first system;

2) 100g of methyl chloride, 1.215g of aluminum sesquichloride and 0.011g of HCl are mixed and aged for 30min at the temperature of minus 85 ℃, an aging system is added into a first system to be stirred and reacted for 2.0h, 20g of butanol is added, discharging is carried out, coagulation is carried out, washing and drying are carried out, and brominated butyl rubber A is obtained.

Example 2

in a 15L stainless steel reaction kettle with a jacket, introducing argon for replacement for 2 times, sequentially adding 2100g of cyclohexane, 220g of 1, 3-butadiene and 1.3g of THF into the polymerization kettle, heating to 42 ℃, and adding 16.5 mmol 1 of n-butyllithium to start reaction for 35min; then adding 310g of isoprene and 1.4g of THF into a polymerization kettle, heating to 52 ℃, and reacting for 43min; then adding 330g of styrene and 3.5g of THF into the polymerization kettle, heating to 62 ℃, and reacting for 65min to obtain a third block system;

Then adding 1100g of cyclohexane, 930g of N-bromosuccinimide and 3.5g of tertiary dodecyl mercaptan into the third block system, heating to 72 ℃, and adding 1.5g of TBHP for reaction for 3.4 hours to obtain a bromination system; and adding 13g of 1, 3-butadiene into the bromination system for end-capping activation, reacting for 22min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent B (Mn is 35000 and Mw/Mn is 2.57).

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

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for 3 times for replacement, adding 200g of methyl chloride, 300g of cyclohexane and 23g of brominated grafting agent B into the polymerization kettle, stirring and dissolving for 35min until the brominated grafting agent B is completely dissolved; then cooling to-82 ℃, sequentially adding 600g of chloromethane, 471g of isobutene and 6g of isoprene, stirring and mixing until the temperature of the system is reduced to-92 ℃ to obtain a first system;

2) 110g of methyl chloride, 1.375g of aluminum sesquichloride and 0.026g of HCl are mixed and aged for 32min at the temperature of minus 87 ℃, an aging system is added into a first system to react for 2.5h under stirring, 23g of butanol is added, and the brominated butyl rubber B is obtained after discharging, condensing, washing and drying.

Example 3

in a 15L stainless steel reaction kettle with a jacket, introducing argon for replacement for 3 times, sequentially adding 2300g of cyclohexane, 230g of 1, 3-butadiene and 1.8g of THF into the polymerization kettle, heating to 45 ℃, and adding 18.1 mmol 1 of n-butyllithium to start reaction for 38min; then adding 330g of isoprene and 1.9g of THF into the polymerization kettle, heating to 54 ℃, and reacting for 48min; then adding 370g of styrene and 4.0g of THF into the polymerization kettle, heating to 65 ℃, and reacting for 70min to obtain a third block system;

adding cyclohexane 1300g, N-bromosuccinimide 980g and tertiary dodecyl mercaptan 4.0g into the third block system, heating to 75 ℃, adding TBHP 2.0g, and reacting for 3.9h to obtain a bromination system; and adding 17g of 1, 3-butadiene into the bromination system for end-capping activation, reacting for 25min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent C (Mn is 38000 and Mw/Mn is 2.73).

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for replacement for 4 times, adding 560g of chloromethane, 240g of cyclohexane and 27g of brominated grafting agent into the polymerization kettle, stirring and dissolving for 39min until the brominated grafting agent is completely dissolved; then cooling to-84 ℃, adding 650g of methyl chloride, 466g of isobutene and 7g of isoprene in sequence, stirring and mixing until the temperature of a polymerization system is reduced to-94 ℃ to obtain a first system;

2) 115g of methyl chloride, 1.465g of aluminum sesquichloride and 0.035g of HCl are mixed and aged for 34min at the temperature of minus 89 ℃, an aging system is added into a first system to react for 2.8h under stirring, 26g of butanol is added, and the brominated butyl rubber C is obtained after discharging, condensing, washing and drying.

Example 4

in a 15L stainless steel reaction kettle with a jacket, introducing argon for replacement for 3 times, sequentially adding 2500g of cyclohexane, 240g of 1, 3-butadiene and 2.0g of THF into the polymerization kettle, heating to 46 ℃, and then adding 19.5 mmol 1 of n-butyllithium to start reaction for 41min; then adding 350g of isoprene and 2.2g of THF into the polymerization kettle, heating to 54 ℃, and reacting for 50min; then adding 400g of styrene and 4.2g of THF into a polymerization kettle, heating to 65 ℃, and reacting for 72min to obtain a third block system;

adding 1500g of cyclohexane, 1000g of N-bromosuccinimide and 4.5g of tertiary dodecyl mercaptan into the third block system, heating to 76 ℃, adding 2.6g of TBHP, and reacting for 4.1h to obtain a bromination system; and adding 21g of 1, 3-butadiene into the bromination system for end-capping activation, reacting for 26min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent D (Mn is 41000 and Mw/Mn is 2.86).

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for replacing for 4 times, adding 500g of methyl chloride, 300g of cyclohexane and 30g of brominated grafting agent D into the polymerization kettle, stirring and dissolving for 41min until the mixture is completely dissolved; then cooling to-86 ℃, sequentially adding 700g of chloromethane, 463g of isobutene and 7g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-95 ℃ to obtain a first system;

2) Then 120g of methyl chloride, 1.578g of aluminum sesquichloride and 0.049g of HCl are mixed and aged for 35min at the temperature of minus 91 ℃, an aging system is added into a first system to be stirred and reacted for 3.2h, 28g of butanol is added, discharging is carried out, coagulation is carried out, washing and drying are carried out, and the brominated butyl rubber D is obtained.

Example 5

in a 15L stainless steel reaction kettle with a jacket, argon is introduced for replacement for 3 times, 2700g of cyclohexane, 260g of 1, 3-butadiene and 2.4g of THF are sequentially added into the polymerization kettle, after the temperature is raised to 47 ℃, 21.3mmo1 of n-butyllithium is added for starting the reaction for 43min; then adding 360g of isoprene and 2.4g of THF into a polymerization kettle, heating to 55 ℃, and reacting for 54min; then adding 420g of styrene and 4.5g of THF into the polymerization kettle, heating to 67 ℃, and reacting for 75min to obtain a third block system;

Then 1700g of cyclohexane, 1040g of N-bromosuccinimide and 5.0g of tertiary dodecyl mercaptan are added into the third block system, the temperature is raised to 77 ℃, 3.0g of TBHPC is added for reaction for 4.4 hours, and a bromination system is obtained; and adding 25g of 1, 3-butadiene into a bromination system for end-capping activation, reacting for 27min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the brominated grafting agent E (Mn is 44000, and Mw/Mn is 2.92).

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for replacing for 4 times, adding 300g of methyl chloride, 700g of cyclohexane and 32g of brominated grafting agent E into the polymerization kettle, stirring and dissolving for 44min until the brominated grafting agent E is completely dissolved; then cooling to-87 ℃, sequentially adding 800g of chloromethane, 460g of isobutene and 8g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-97 ℃ to obtain a first system;

2) 130g of methyl chloride, 1.612g of aluminum sesquichloride and 0.055g of HCl are mixed and aged for 37min at the temperature of minus 91 ℃, an aging system is added into a first system to react for 3.5h under stirring, 30g of butanol is added, and the brominated butyl rubber E is obtained after discharging, condensing, washing and drying.

Example 6

in a 15L stainless steel reaction kettle with a jacket, argon is introduced for replacement for 4 times, 290 g of cyclohexane, 280g of 1, 3-butadiene and 2.8g of THF are sequentially added into the polymerization kettle, after the temperature is raised to 49 ℃, 22.7mmo1 of n-butyllithium is added for starting the reaction for 46min; then adding 380g of isoprene and 2.8g of THF into a polymerization kettle, heating to 57 ℃, and reacting for 56min; adding 460g of styrene and 4.7g of THF into a polymerization kettle, heating to 68 ℃, and reacting for 78min to obtain a third block system;

adding 190 g of cyclohexane, 1070g of N-bromosuccinimide and 5.5g of tertiary dodecyl mercaptan into the third block system, heating to 78 ℃, adding 3.5g of TBHPC for reacting for 4.8 hours to obtain a bromination system; then adding 28g of 1, 3-butadiene into the bromination system for end-capping activation, reacting for 28min until no free monomer exists, and carrying out wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent F (Mn is 46000, mw/Mn is 3.02).

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for replacement for 5 times, adding 600g of methyl chloride, 400g of cyclohexane and 36g of brominated grafting agent F into the polymerization kettle, stirring and dissolving for 47min until the mixture is completely dissolved; then cooling to-89 ℃, sequentially adding 900g of chloromethane, 455g of isobutene and 9g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-98 ℃ to obtain a first system;

140g of methyl chloride, 1.753g of aluminum sesquichloride and 0.063g of HCl are mixed and aged for 39min at the temperature of minus 93 ℃, an aging system is added into a first system to be stirred and reacted for 3.8h, 33g of butanol is added, and the mixture is discharged, condensed, washed and dried to obtain the brominated butyl rubber F.

Example 7

in a 15L stainless steel reaction kettle with a jacket, introducing argon for replacement for 4 times, sequentially adding 3000g of cyclohexane, 300g of 1, 3-butadiene and 3.0g of THF into the polymerization kettle, heating to 50 ℃, and adding 24.5 mmol 1 of n-butyllithium to start reaction for 50min; then 400g of isoprene and 3.0g of THF are added into the polymerization kettle, and the reaction is carried out for 60min after the temperature is raised to 60 ℃; then adding 500g of styrene and 5.0g of THF into a polymerization kettle, heating to 70 ℃, and reacting for 80min to obtain a third block system;

then adding 2000g of cyclohexane, 1100g of N-bromosuccinimide and 6.0g of tertiary dodecyl mercaptan into the third block system, heating to 80 ℃, adding 4.0g of TBHPC for reacting for 5.0h to obtain a bromination system; then adding 30G of 1, 3-butadiene into the bromination system for end-capping activation, reacting for 30min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent G (Mn is 49000, mw/Mn is 3.15).

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for replacement for 5 times, adding 500G of chloromethane, 500G of cyclohexane and 40G of brominated grafting agent into the polymerization kettle, stirring and dissolving for 50min until the brominated grafting agent is completely dissolved; then cooling to-90 ℃, sequentially adding 1000g of chloromethane, 450g of isobutene and 10g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-100 ℃ to obtain a first system;

2) 150G of methyl chloride, 1.962G 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 react for 4.0h under stirring, 35G of butanol is added, discharging is performed, coagulation is performed, washing is performed, and the brominated butyl rubber G is obtained after drying.

Example 8

in a 15L stainless steel reaction kettle with a jacket, introducing argon for replacement for 2 times, sequentially adding 2000g of cyclohexane, 190g of 1, 3-butadiene and 1.0g of THF into the polymerization kettle, heating to 40 ℃, and then adding 12.5 mmol 1 of n-butyllithium to start reaction for 30min; then adding 290g of isoprene and 1.0g of THF into the polymerization kettle, heating to 50 ℃, and reacting for 40min; then adding 300g of styrene and 3.0g of THF into a polymerization kettle, heating to 60 ℃, and reacting for 60min to obtain a third block system;

Then 1000g of cyclohexane, 900g of N-bromosuccinimide and 3.0g of tertiary dodecyl mercaptan are added into the third block system, the temperature is raised to 70 ℃, and 1.0g of TBHP is added for reaction for 3.0h, so that a bromination system is obtained; and adding 10g of 1, 3-butadiene into a bromination system for end-capping activation, reacting for 20min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent H (Mn is 29500, mw/Mn is 2.19).

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for 3 times for replacement, adding 150g of chloromethane, 350g of cyclohexane and 20g of brominated grafting agent H into the polymerization kettle, stirring and dissolving for 30min until the brominated grafting agent H is completely dissolved; then cooling to-80 ℃, sequentially adding 500g of chloromethane, 475g of isobutene and 5g of isoprene, stirring and mixing until the system temperature is reduced to-90 ℃ to obtain a first system;

2) 100g of methyl chloride, 1.215g of aluminum sesquichloride and 0.011g of HCl are mixed and aged for 30min at the temperature of minus 85 ℃, an aging system is added into a first system to be stirred and reacted for 2.0H, 20g of butanol is added, discharging is carried out, coagulation is carried out, washing and drying are carried out, and brominated butyl rubber H is obtained.

Example 9

in a 15L stainless steel reaction kettle with a jacket, introducing argon for replacement for 4 times, sequentially adding 3000g of cyclohexane, 310g of 1, 3-butadiene and 3.0g of THF into the polymerization kettle, heating to 50 ℃, and then adding 26.1 mmol 1 of n-butyllithium to start reaction for 50min; then adding 410g of isoprene and 3.0g of THF into a polymerization kettle, heating to 60 ℃, and reacting for 60min; then adding 520g of styrene and 5.0g of THF into the polymerization kettle, heating to 70 ℃, and reacting for 80min to obtain a third block system;

then adding 2000g of cyclohexane, 1100g of N-bromosuccinimide and 6.0g of tertiary dodecyl mercaptan into the third block system, heating to 80 ℃, adding 4.0g of TBHPC for reacting for 5.0h to obtain a bromination system; then adding 30g of 1, 3-butadiene into the bromination system for end-capping activation, reacting for 30min until no free monomer exists, and performing wet condensation, washing and drying on the glue solution to obtain the bromination grafting agent J (Mn is 53000, mw/Mn is 3.19).

1) In a 4L stainless steel reaction kettle with a jacket, introducing nitrogen for replacement for 5 times, adding 500g of chloromethane, 500g of cyclohexane and 40g of brominated grafting agent J into the polymerization kettle, stirring and dissolving for 50min until the brominated grafting agent J is completely dissolved; then cooling to-90 ℃, sequentially adding 1000g of chloromethane, 450g of isobutene and 10g of isoprene, stirring and mixing until the temperature of a polymerization system is reduced to-100 ℃ to obtain a first system;

2) 150g of methyl chloride, 1.962g 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 react for 4.0h under stirring, 35g of butanol is added, discharging is performed, coagulation is performed, washing is performed, and drying is performed to obtain the brominated butyl rubber J.

Comparative example 1

The preparation of 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-bromosuccinimide of example 1.

The preparation method of the brominated butyl rubber a of this comparative example is substantially the same as that of example 1, except that the brominated butyl rubber a of example 1 is replaced with the brominated butyl rubber a.

Comparative example 2

The preparation of the brominated grafting agent b of this comparative example is essentially identical to that of example 2, except that H is used ₂ O ₂ The TBHP of example 2 was replaced.

The preparation method of the brominated butyl rubber B of this comparative example is substantially the same as that of example 2, except that the brominated butyl rubber B of example 2 is replaced with the brominated butyl rubber B.

Comparative example 3

The preparation of the brominated grafting agent c of this comparative example was essentially identical to that of example 3, except that 500g of N-bromosuccinimide was used in step 1).

The preparation method of the brominated butyl rubber C of this comparative example is substantially the same as that of example 3, except that the brominated butyl rubber C of example 3 is replaced with the brominated butyl rubber C.

Comparative example 4

The preparation of the brominated butyl rubber D of this comparative example was substantially identical to that of example 4, except that 10g of brominated grafting agent D was added by mass.

Comparative example 5

The preparation method of the brominated grafting agent e of this comparative example is substantially the same as that of example 5, except that the step of preparing a styrene homo-block is not included, and the copolymer of 1, 3-butadiene homo-block and isoprene homo-block is directly subjected to bromination treatment.

The preparation method of the brominated butyl rubber E of this comparative example is substantially the same as that of example 5, except that the brominated butyl rubber E of example 5 is replaced with brominated butyl rubber E.

Comparative example 6

The preparation method of the brominated grafting agent f of the comparative example is basically the same as that of example 6, except that the end-capping activation step is not included, and the bromination system is directly subjected to condensation, washing and drying to prepare the brominated grafting agent f.

The preparation method of the brominated butyl rubber F of this comparative example is substantially the same as that of example 6, except that the brominated butyl rubber F in example 6 is replaced with the brominated butyl rubber F.

Comparative example 7

The preparation method of the brominated butyl rubber g of this comparative example is basically the same as that of example 7, except that the addition amount of isoprene is changed in the preparation process of the brominated butyl rubber g, namely, the addition mass of the brominated grafting agent D, the isobutene and the isoprene is 40g, 450g and 20g respectively.

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. Using polystyrene standard sample as calibration curve, mobile phase as tetrahydrofuran, column temperature of 40deg.C, sample concentration of 1mg/ml, and sample injection amount of50 mu L, flow rate of 1 ml.min ^-1 The elution time was 40min.

TABLE 1

	Bromine mass percent%	Number average molecular weight/molecular weight distribution
			Example 1	14.1％	31000/2.24
Example 2	15.3％	35000/2.57
			Example 3	16.1％	38000/2.73
Example 4	16.9％	41000/2.86
			Example 5	17.3％	44000/2.92
Example 6	17.9％	46000/3.02
			Example 7	18.5％	49000/3.15
Example 8	19.2％	29500/2.19
			Example 9	19.9％	53000/3.19
Comparative example 1	10.5％	29000/1.83
			Comparative example 2	9.3％	28000/1.58
Comparative example 3	12.7％	32000/2.05
			Comparative example 4	16.9％	41000/2.86
Comparative example 5	17.2％	28000/1.95
			Comparative example 6	19.1％	46000/3.01
Comparative example 7	19.6％	49000/3.15

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 with the bromine content not less than 14 wt%.

2. The following parameters of the brominated butyl rubber in the above examples and comparative examples were examined, and the results are shown in Table 2.

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

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.

Vulcanization characteristics: 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.

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

TABLE 2

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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, aging resistance, tensile strength 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 30000 to 50000 and a molecular weight distribution of 2.24 to 3.15.

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 total mass of the monomers to the first monomer and the first structure regulator is 1: (0.2-0.3): (0.001-0.003); and/or the number of the groups of groups,

5. The brominated grafting agent of claim 3 or 4, wherein the organic brominating agent is selected from one of N-bromosuccinimide, N-bromophthalamide, N '-dibromo-5, 5' -dimethylhydantoin; and/or, the organic bromination initiator is an organic peroxide.

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 graft prepared by the method of 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): (0.2-0.3): (0.0003 to 0.004);

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