Block copolymers and methods for their preparation, brominated block copolymers and applications thereof

Abstract

This invention relates to the field of polymer synthesis and preparation, and discloses a block copolymer and its preparation method, a brominated block copolymer and its applications. The block copolymer possesses PS... 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The block copolymer shown contains at least 80 mol% propylene-based structural units based on the total molar number of HPIR; at least 80 mol% vinyl-based structural units based on the total molar number of HVBR; styrene block content is 20-40 wt%; and the molecular weight distribution of the block polymer is 1-1.2. This block copolymer, comprising high-propylene-content polyisoprene blocks and high-vinyl-content polybutadiene blocks, effectively improves the selectivity and efficiency of bromination. The resulting brominated block copolymer exhibits high thermal decomposition temperature and high glass transition temperature, making it suitable as a flame retardant for polystyrene foam exterior wall insulation materials.

Description

Technical Field

[0001] This invention relates to the field of polymer material synthesis and preparation technology, specifically to a block copolymer and its preparation method, a brominated block copolymer and its application. Background Technology

[0002] Hexabromocyclododecane (HBCD) is the most important flame retardant for expanded polystyrene (EPS) and extruded polystyrene (XPS) exterior wall insulation materials. However, HBCD has poor thermal stability, decomposing to produce hydrogen bromide at 150°C and undergoing a violent debromination reaction at 190°C, causing damage to the eyes, skin, and respiratory system. Although HBCD has excellent flame retardant effects, it poses a potential long-term hazard to the human environment. With the increasing use of HBCD, its persistence and long-distance migration in environmental media such as air, water, soil sediments, and sludge are becoming increasingly prominent, and its bioaccumulation and biomagnification in fish, birds, and mammals are also becoming more serious. To strengthen the management of chemicals and reduce the hazards caused by chemicals, especially toxic and hazardous chemicals, the Stockholm Convention stipulates a time-limited withdrawal of HBCD from the flame retardant market. HBCD will be withdrawn from the global exterior wall insulation flame retardant market.

[0003] Following the development trends of flame retardants and combining them with the production process of polystyrene insulation foam, polymeric additives will become a sustainable flame retardant solution in the production and application of polystyrene foam. Polymeric additives have higher molecular weights, increasing resistance to migration, extraction, and evaporation, thereby reducing the risk of flame retardants being released from the polymer into the environment. High molecular weight polymers are difficult to pass through biofilms, making them less susceptible to absorption by the intact digestive tract, reducing bioavailability, potential exposure risks, and adverse health effects. Among all polymeric additives, the brominated products of thermoplastic elastomers obtained from the polymerization of styrene and conjugated dienes, due to their high molecular weight and excellent flame retardant properties, represent the most efficient and sustainable solution among polymeric flame retardants.

[0004] The conventional styrene and conjugated diene block polymers on the market mainly include SBS and SIS. However, due to the low content of side groups of conjugated dienes, there are fewer double bonds that can participate in the bromination reaction. As a result, the thermal decomposition temperature of the bromination products of the prepared styrene and conjugated diene block polymers is low, which cannot meet the requirements for the use of exterior wall insulation flame retardants. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low bromination efficiency of block copolymers, low bromine content of the brominated products, and insufficient thermal decomposition temperature to meet the flame retardant requirements of external wall insulation materials in the prior art. This invention provides a block copolymer and its preparation method, a brominated block copolymer comprising polyisoprene blocks with high propylene content and polybutadiene blocks with high vinyl content, which can effectively improve the selectivity and efficiency of bromination, and result in a brominated block copolymer with high thermal decomposition temperature and high glass transition temperature.

[0006] To achieve the above objectives, a first aspect of the present invention provides a block copolymer, characterized in that the block copolymer has PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The block structure shown;

[0007] Among them, PS 1 and PS 2 Each is an independent styrene block, HPIR 1 and HPIR 2 Each is independently a high-propylene polyisoprene block, while HVBR is a high-vinyl polybutadiene block;

[0008] Based on the total molar number of HPIR in the block copolymer, it contains at least 80 mol% of propylene structural units; based on the total molar number of HVBR in the block copolymer, it contains at least 80 mol% of vinyl structural units.

[0009] Based on the total weight of the block copolymer, the content of the styrene block is 20-40 wt%.

[0010] The block copolymer has a molecular weight distribution of 1-1.2.

[0011] A second aspect of the present invention provides a method for preparing a block copolymer, characterized in that the preparation method includes the following steps:

[0012] (1) In a nonpolar hydrocarbon solvent, in the presence of a composite structure modifier and an initiator, styrene monomer 1 undergoes a first anionic polymerization reaction to obtain a product containing PS. 1 Polymer solutions with a specific structure;

[0013] (2) To the substance containing PS 1 Isoprene monomer 1 was added to the polymer solution, and a second anionic solution polymerization was carried out to obtain a product containing PS. 1 -HPIR 1 Copolymer solutions with structural features;

[0014] (3) To the substance containing PS 1 -HPIR 1 Butadiene monomer is added to the copolymer solution of the structure, and a third anionic polymerization reaction is carried out to obtain PS. 1 -HPIR 1 -HVBR structured copolymer solution;

[0015] (4) To the substance containing PS 1 -HPIR 1 Isoprene monomer 2 was added to the copolymer solution with the -HVBR structure to carry out the fourth anionic polymerization reaction, resulting in PS. 1 -HPIR 1 -HVBR-HPIR 2 Copolymer solutions with structural features;

[0016] (5) To the substance containing PS 1 -HPIR 1 -HVBR-HPIR 2 Styrene monomer 2 was added to the copolymer solution of the structure to carry out the fifth anionic polymerization, resulting in PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The copolymer solution of the structure, for the PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The copolymer solution of the structure is dried to obtain the block copolymer;

[0017] The composite structure modifier comprises component A, component B, and component C. Component A is a polar ether compound and / or a polar amine compound, component B is a polar ether compound and / or a polar amine compound, and component C is selected from at least one of sodium alkoxide, potassium alkoxide, sodium alkylbenzene sulfonate, and potassium alkylbenzene sulfonate.

[0018] The polymerization temperatures of the first anionic polymerization reaction, the second anionic polymerization reaction, the third anionic polymerization reaction, the fourth anionic polymerization reaction, and the fifth anionic polymerization reaction are each independently 0-50℃;

[0019] Based on the total weight of styrene monomer, isoprene monomer, and butadiene monomer, the amount of styrene monomer used is 20-40 wt%.

[0020] A third aspect of the present invention provides a block copolymer prepared by the above-described preparation method.

[0021] A fourth aspect of the present invention provides a brominated block copolymer, characterized in that the brominated block copolymer is obtained by bromination of the above-mentioned block copolymer.

[0022] The fifth aspect of this invention provides the application of the above-mentioned brominated block copolymer in an external wall insulation flame retardant.

[0023] Through the above technical solutions, the block copolymers and their preparation methods, brominated block copolymers and their applications provided by the present invention achieve the following beneficial effects:

[0024] The block copolymer provided by the present invention comprises polyisoprene blocks with high propylene content and polybutadiene blocks with high vinyl content, which can effectively improve the selectivity and efficiency of bromination, and make the obtained brominated block copolymer have high thermal decomposition temperature and high glass transition temperature.

[0025] Specifically, the block copolymer provided by the present invention contains at least 80 mol% of propylene structural units in the polyisoprene block and at least 80 mol% of vinyl structural units in the polybutadiene block. The block copolymer has a narrow molecular weight distribution, and the styrene block content in the block copolymer is 20-40 wt%. This allows more than 95% of the double bonds in the block copolymer to be brominated, thereby giving the brominated block copolymer a high thermal decomposition temperature and a high glass transition temperature. It is particularly suitable as a flame retardant for exterior wall insulation materials such as polystyrene foam. Detailed Implementation

[0026] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0027] A first aspect of the present invention provides a block copolymer, characterized in that the block copolymer has PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The block structure shown;

[0028] Among them, PS 1 and PS 2 Each is an independent styrene block, HPIR 1 and HPIR 2 Each is independently a high-propylene polyisoprene block, while HVBR is a high-vinyl polybutadiene block;

[0029] Based on the total molar number of HPIR in the block copolymer, it contains at least 80 mol% of propylene structural units; based on the total molar number of HVBR in the block copolymer, it contains at least 80 mol% of vinyl structural units.

[0030] Based on the total weight of the block copolymer, the content of the styrene block is 20-40 wt%.

[0031] The block copolymer has a molecular weight distribution of 1-1.2.

[0032] Generally, for butadiene structural units, the vinyl structure has the highest bromination efficiency, followed by the trans structure, and the cis structure has the lowest bromination efficiency; for isoprene structural units, the bromination efficiency of the propylene structure is higher than that of the 1,4- structure. To obtain brominated block copolymers with higher bromine content while maintaining the same number of double bonds, it is necessary to increase the side group content of both butadiene and isoprene.

[0033] In this invention, the block copolymer provided by this invention has the specific block structure described above, and the block copolymer contains polyisoprene blocks with high propylene content and polybutadiene blocks with high vinyl content. As a result, the block copolymer contains a high side group content, which can effectively improve the selectivity and efficiency of bromination, and make the obtained brominated block copolymer have a high thermal decomposition temperature and a high glass transition temperature.

[0034] Specifically, the block copolymer provided by the present invention contains at least 80 mol% propylene structural units in the polyisoprene block and at least 80 mol% vinyl structural units in the polybutadiene block. The block copolymer has a narrow molecular weight distribution, and the styrene block content in the block copolymer is 20-40 wt%. This allows more than 95% of the double bonds in the block copolymer to be brominated, thereby giving the brominated block copolymer a high thermal decomposition temperature and a high glass transition temperature. It is particularly suitable as a flame retardant for exterior wall insulation materials such as polystyrene foam.

[0035] In this invention, high-propylene polyisoprene block copolymer (HPIR) 1 and HPIR 2 The content of propylene structural units in the copolymer (Ia%), the content of vinyl structural units in high-vinyl polybutadiene block copolymer (HVBR) (Bv%), and the content of high-propylene polyisoprene block copolymer (HPIR) in the block copolymer. 1 +HPIR 2 The content (Ip%) of ) was determined by proton nuclear magnetic resonance spectroscopy.

[0036] Furthermore, based on the total number of moles of HPIR in the block copolymer, it contains at least 82 mol% of propylene-based structural units, preferably at least 84 mol% of propylene-based structural units, and more preferably at least 86 mol% of propylene-based structural units.

[0037] Furthermore, based on the total molar number of HVBR in the block copolymer, it contains at least 82 mol% of vinyl structural units, preferably at least 84 mol% of vinyl structural units, and more preferably at least 86 mol% of vinyl structural units.

[0038] Furthermore, based on the total weight of the block copolymer, the styrene block (PS) 1 +PS 2 The content (St%) of ) is 22-35wt%.

[0039] According to the present invention, PS 1 and PS 2 The weight ratio is 3 / 7-7 / 3.

[0040] In this invention, PS 1 and PS 2 Independent representation of styrene blocks, PS 1 and PS 2 Same or different.

[0041] In this invention, the content of styrene blocks and PS in the block copolymer are controlled. 1 and PS 2 The weight ratio must meet the above range to ensure PS 1 and PS 2 Chain segment length, specifically, PS 1 and PS 2 The number-average molecular weights of each are independently at least 8000, if PS 1 and PS 2 The number-average molecular weight is too low to effectively form a phase-separated structure; PS 1 and PS 2 Each block polymer has a number-average molecular weight that does not exceed 20,000 independently; otherwise, the processing performance of the block polymer is too poor, which is not conducive to stable industrial production.

[0042] In this invention, the content (St%) of styrene blocks in the block copolymer was determined by 1H NMR spectroscopy. 1 and PS 2 The weight ratio is calculated based on the amount of styrene monomer added.

[0043] Furthermore, PS 1 and PS 2 The weight ratio is 4 / 6 to 6 / 4.

[0044] According to the present invention, the content of the high-propylene polyisoprene block is 30-50 wt%, based on the total weight of the block polymer.

[0045] According to the present invention, HPIR 1 and HPIR 2 The weight ratio is 4 / 6 to 6 / 4.

[0046] In this invention, the content of high-propylene polyisoprene blocks in the block polymer and the HPIR are controlled. 1 and HPIR 2 The weight ratio must meet the above range to ensure that there are enough double bonds in the block copolymer that can undergo addition reactions, so as to increase the bromine content in the final brominated block copolymer, thereby ensuring that the brominated product has high thermal stability and glass transition temperature.

[0047] In this invention, the high-propylene polyisoprene block copolymer (HPIR) 1 +HPIR 2 The content (Ip%) was determined by proton nuclear magnetic resonance spectroscopy (HMR). 1 and HPIR 2 The weight ratio is calculated based on the amount of monomer added.

[0048] Furthermore, based on the total weight of the block polymer, the content of the high-propylene polyisoprene block is 35-45 wt%.

[0049] According to the present invention, the content of the high-vinyl polybutadiene block is 20-40 wt%, based on the total weight of the block copolymer.

[0050] In this invention, when the content of high-vinyl polybutadiene blocks in the block copolymer is controlled to meet the above-mentioned range, it can be ensured that there are enough double bonds in the block copolymer that can undergo addition reactions, so as to increase the bromine content in the final brominated block polymer, thereby ensuring that the brominated product has high thermal stability and glass transition temperature.

[0051] Furthermore, based on the total weight of the block copolymer, the content of the high-vinyl polybutadiene block is 25-35 wt%.

[0052] According to the present invention, the number average molecular weight of the block copolymer is 50,000-200,000, preferably 80,000-150,000.

[0053] In this invention, controlling the number-average molecular weight of the block copolymer serves three purposes: first, to provide more double bonds that can undergo bromination; second, to ensure good phase separation; and third, to guarantee the processability of the block copolymer. When the number-average molecular weight of the block copolymer is below 50,000, the number of double bonds capable of bromination on a single molecular chain is relatively small, which is detrimental to the preparation of brominated block copolymers with good thermal stability. When the number-average molecular weight of the block copolymer is above 200,000, the processability of the block copolymer is too poor, which is not conducive to stable industrial production.

[0054] According to the present invention, the molecular weight distribution of the block copolymer is 1-1.2, preferably 1.01-1.15, and more preferably 1.02-1.1.

[0055] In this invention, to prepare brominated block copolymers with better thermal stability, PS before bromination is required. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block copolymers have a narrow molecular weight distribution, PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Low molecular weight components in block copolymers can have an adverse effect on the properties of brominated products, so it is necessary to control the content of low molecular weight components as much as possible.

[0056] A second aspect of the present invention provides a method for preparing a block copolymer, characterized in that the preparation method includes the following steps:

[0057] (1) In a nonpolar hydrocarbon solvent, in the presence of a composite structure modifier and an initiator, styrene monomer 1 undergoes a first anionic polymerization reaction to obtain a product containing PS. 1 Polymer solutions with a specific structure;

[0058] (2) To the substance containing PS 1 Isoprene monomer 1 was added to the polymer solution, and a second anionic solution polymerization was carried out to obtain a product containing PS. 1 -HPIR 1 Copolymer solutions with structural features;

[0059] (3) To the substance containing PS 1 -HPIR 1 Butadiene monomer is added to the copolymer solution of the structure, and a third anionic polymerization reaction is carried out to obtain a product containing PS. 1 -HPIR 1 -HVBR structured copolymer solution;

[0060] (4) To the substance containing PS 1-HPIR 1 Isoprene monomer 2 was added to a copolymer solution with a -HVBR structure, and a fourth anionic polymerization reaction was carried out to obtain a product containing PS. 1 -HPIR 1 -HVBR-HPIR 2 Copolymer solutions with structural features;

[0061] (5) To the substance containing PS 1 -HPIR 1 -HVBR-HPIR 2 Styrene monomer 2 was added to the copolymer solution of the structure to carry out the fifth anionic polymerization, resulting in a product containing PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The copolymer solution of the structure, for the PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The copolymer solution of the structure is dried to obtain the block copolymer;

[0062] The composite structure modifier comprises component A, component B, and component C. Component A is a polar ether compound and / or a polar amine compound, component B is a polar ether compound and / or a polar amine compound, and component C is selected from at least one of sodium alkoxide, potassium alkoxide, sodium alkylbenzene sulfonate, and potassium alkylbenzene sulfonate.

[0063] The polymerization temperatures of the first anionic polymerization reaction, the second anionic polymerization reaction, the third anionic polymerization reaction, the fourth anionic polymerization reaction, and the fifth anionic polymerization reaction are each independently 0-50℃;

[0064] Based on the total weight of styrene monomer, isoprene monomer, and butadiene monomer, the amount of styrene monomer used is 20-40 wt%.

[0065] In this invention, styrene, butadiene, and isoprene are anionicly polymerized in the presence of a composite regulator containing specific components. The polymerization temperature of the anionic polymerization reaction and the amount of styrene monomer are controlled, thereby obtaining the block copolymer with a specific structure as described in the first aspect of this invention. In particular, the block copolymer contains polyisoprene blocks with high propylene content and polybutadiene blocks with high vinyl content. As a result, the block copolymer contains a high side group content, which can effectively improve the selectivity and efficiency of bromination, and make the obtained brominated block copolymer have a high thermal decomposition temperature and a high glass transition temperature.

[0066] Specifically, in the block copolymer provided by the present invention, the polyisoprene block contains at least 80 mol% of propylene structural units, the polybutadiene block contains at least 80 mol% of vinyl structural units, and the styrene block content in the block copolymer is 20-40 wt%, which enables more than 95% of the double bonds in the block copolymer to be brominated and added. Furthermore, the block copolymer has a narrow molecular weight distribution, resulting in a brominated block copolymer with a high thermal decomposition temperature and a high glass transition temperature, making it particularly suitable as a flame retardant for polystyrene foam exterior wall insulation materials.

[0067] In this invention, by independently controlling the polymerization temperatures of the first, second, third, fourth, and fifth anionic polymerization reactions to be between 0 and 50°C, the microstructure of the block copolymer can be controlled, resulting in a block copolymer with the special block structure described in the first aspect of this invention. Specifically, if the polymerization temperature is too low, the polymerization rate is slow, which is not conducive to large-scale production and results in high energy consumption per unit product; if the polymerization temperature is too high, the ability of the composite structure regulator to control the microstructure of the block copolymer decreases, which is not conducive to the preparation of block copolymers with high side group content.

[0068] Furthermore, the polymerization temperatures of the first anionic polymerization reaction, the second anionic polymerization reaction, the third anionic polymerization reaction, the fourth anionic polymerization reaction, and the fifth anionic polymerization reaction are each independently 0-40°C.

[0069] In this invention, the time for the first anionic polymerization reaction is 5-15 min, preferably 8-12 min.

[0070] In one specific embodiment of the present invention, step (1) includes: mixing a nonpolar hydrocarbon solvent, a composite structure modifier, and styrene monomer 1 at a lower temperature to obtain a mixture; then adding an initiator to the mixture to carry out the first anionic polymerization reaction to obtain a product containing PS. 1 Polymer solutions with a specific structure.

[0071] In this invention, the second anionic polymerization reaction takes 15-30 min, preferably 18-25 min.

[0072] In this invention, the time for the third anionic polymerization reaction is 15-25 min, preferably 18-22 min.

[0073] In this invention, the time for the fourth anionic polymerization reaction is 15-30 min, preferably 18-25 min.

[0074] In this invention, the time for the fifth anionic polymerization reaction is 5-15 min, preferably 8-12 min.

[0075] According to the present invention, component A has the structure shown in Formula I;

[0076]

[0077] In this context, Q1, Q2, and Q3 are each independently N or O, n1 is an integer from 2 to 6, m is 0 or 1, r is 0 or 1, n2 is an integer from 0 to 4, and q1 and q2 are each independently 1 or 2.

[0078] In this invention, component A, which has the above-mentioned specific structure, is selected. It has strong structural control over the anionic polymerization of butadiene and isoprene, and can prepare block copolymers with high side group content.

[0079] Further, component A is selected from at least one of diethylene glycol dimethyl ether (2G) (Q1, Q2 and Q3 are 0, q1 and q2 are 1, m is 1, r is 0, n1 and n2 are 2), tetramethylethylenediamine (Q1 and Q3 are N, q1 and q2 are 2, m is 0, r is 0, n1 is 2, n2 is 0), pentamethyldivinyltriamine (Q1, Q2 and Q3 are N, q1 and q2 are 2, m is 1, r is 1, n1 and n2 are 2) and bis(dimethylaminoethyl) ether (BDMAEE) (Q1 and Q3 are N, Q2 is 0, q1 and q2 are 2, m is 1, r is 0, n1 and n2 are 2); preferably diethylene glycol dimethyl ether and / or bis(dimethylaminoethyl) ether.

[0080] According to the present invention, component B has the structure shown in Formula II;

[0081]

[0082] Wherein, R1 and R2 are each independently H or CH3, and R3 is a C2-C6 alkoxy group.

[0083] In this invention, component B, which has the above-mentioned specific structure, is selected. It has low temperature sensitivity and strong ability to adjust the polymerization rate, which can significantly improve the anionic polymerization rate and reduce the degree of side reaction of component A.

[0084] Furthermore, component B is selected from bis(tetrahydrofurfuryl)propane (DTHFP) (R1 and R2 are CH3, R3 is CH3). Tetrahydrofurfuryl ethyl ether (ETE) (R1 and R2 are H, R3 is ethoxy) and N,N-dimethyltetrahydrofurfurylamine (R1 and R2 are H, R3 is ethoxy) At least one of the following.

[0085] According to the present invention, component C is selected from sodium alkoxide and / or sodium alkylbenzene sulfonate, preferably selected from at least one of sodium terpineol (STP), sodium menthol and sodium dodecylbenzene sulfonate (SDBS), and more preferably sodium terpineol.

[0086] In this invention, component C, which has the above-mentioned specific type, is selected. It has a synergistic effect with component A, which can significantly reduce the temperature sensitivity of component A and improve the control of component A over the microstructure of butadiene and styrene anionic polymerization.

[0087] According to the present invention, the amount of component A is 0.2-0.8 mol relative to 1 mol of initiator.

[0088] In this invention, component A is mainly used to control the side group content of the conjugated diene block (polybutadiene and / or polyisoprene) in the block copolymer. When the amount of component A is too small, the side group content of the block copolymer cannot meet the requirements. When the amount of component A is too large, the degree of side reaction increases and the molecular weight distribution of the product becomes wider.

[0089] Furthermore, the amount of component A is 0.3-0.6 mol relative to 1 mol of initiator.

[0090] According to the present invention, the amount of component B is 0.5-3 mol relative to 1 mol of initiator.

[0091] In this invention, component B is mainly used to adjust the polymerization rate of the anionic polymerization reaction. In order to reduce the side reactions caused by component A, it is necessary to increase the anionic polymerization rate. If the amount of component B is too small, the polymerization rate will not be significantly improved. If the amount of component B is too large, the polymerization rate will be difficult to control and will affect the ability of component A to control the content of conjugated diene side groups in the block copolymer.

[0092] Furthermore, the amount of component B is 0.8-2 mol relative to 1 mol of initiator.

[0093] According to the present invention, the amount of component C is 0.03-0.1 mol relative to 1 mol of initiator.

[0094] In this invention, component C is mainly used to enhance the control of component A over the microstructure of the conjugated diene in the block copolymer, while reducing the temperature sensitivity and side reaction degree of component A. If the amount of component C is too small, it cannot fully exert the above-mentioned effects; if the amount of component C is too large, it will lead to an increase in the degree of side reactions and a wider molecular weight distribution.

[0095] Furthermore, the amount of component C used is 0.04-0.08 mol relative to 1 mol of initiator.

[0096] In this invention, there is no particular limitation on the type of nonpolar hydrocarbon solvent; conventional nonpolar hydrocarbon solvents in the art, such as cyclohexane, can be used. There is no particular limitation on the amount of nonpolar hydrocarbon solvent used, as long as it is sufficient to fully dissolve the composite structure modifier, etc.

[0097] In this invention, there is no particular limitation on the type of initiator; commonly used anionic polymerization initiators in the art, such as n-butyllithium, can be used. The amount of initiator can also follow conventional methods in the art; for example, based on 100g of polymeric monomers (styrene, butadiene, and isoprene), the amount of initiator is 0.5-2 mmol.

[0098] According to the present invention, based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of styrene monomer is 20-40 wt%, preferably 22-35 wt%.

[0099] According to the present invention, the weight ratio of styrene monomer 1 to styrene monomer 2 is 3 / 7-7 / 3, preferably 4 / 6-6 / 4.

[0100] According to the present invention, based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of isoprene monomer is 30-50 wt%, preferably 35-45 wt%.

[0101] According to the present invention, the weight ratio of isoprene monomer 1 to isoprene monomer 2 is 4 / 6 to 6 / 4.

[0102] According to the present invention, based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of butadiene monomer is 20-40 wt%, preferably 25-35 wt%.

[0103] In this invention, controlling the order of adding the polymeric monomers styrene, butadiene, and isoprene, as well as the amount added in each step, can yield block copolymers with phase separation structures, thereby enabling the brominated block copolymers obtained by bromination to have higher thermal stability.

[0104] According to the present invention, the preparation method further includes: processing the PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The block polymer solution of the structure is used to terminate the reaction. Generally, the terminator for anionic polymerization can be acid, alcohol, or water, but acid and alcohol have an adverse effect on bromination reaction. Therefore, deionized water is preferred as the terminator in the termination reaction of this invention.

[0105] In this invention, the preparation method is carried out in the presence of nitrogen.

[0106] A third aspect of the present invention provides a block copolymer prepared by the above-described preparation method.

[0107] A fourth aspect of the present invention provides a brominated block copolymer, characterized in that the brominated block copolymer is obtained by bromination of the above-mentioned block copolymer.

[0108] In this invention, when the block copolymer provided in the first or third aspect of this invention is brominated, the bromination reaction occurs only at HPIR. 1 HPIR 2 Performed on HVBR blocks, PS 1 and PS 2 Blocks do not participate in bromination reactions, HPIR 1 HPIR 2 In HVBR blocks, more than 95% of the double bonds are brominated. The number of unreacted double bonds in the block copolymer determines the bromine content of the brominated block copolymer. Preferably, the bromine content of the brominated block copolymer is 60-68 wt%, more preferably 61-67 wt%, and more preferably 62-66 wt%.

[0109] According to the present invention, the number average molecular weight of the brominated block copolymer is 50,000-200,000, preferably 80,000-150,000.

[0110] In this invention, during the bromination of isoprene and butadiene block polymers in the block copolymer, some molecular chains break down, and the number-average molecular weight of the final brominated block copolymer is basically the same as that of the block copolymer before bromination.

[0111] According to the present invention, the molecular weight distribution of the brominated block copolymer is 1-1.2, preferably 1.01-1.15, and more preferably 1.02-1.1. In the present invention, the molecular weight distribution of the brominated block copolymer is substantially the same as that of the unbrominated block copolymer.

[0112] According to the present invention, the 5wt% thermogravimetric temperature of the brominated block copolymer is greater than or equal to 260°C, preferably 260-268°C, and more preferably 261-267°C.

[0113] According to the present invention, the glass transition temperature of the brominated block copolymer is greater than or equal to 120°C, preferably 121-133°C, and more preferably 123-131°C.

[0114] The fourth aspect of the present invention provides the application of the above-mentioned brominated block copolymer in an external wall insulation flame retardant.

[0115] The present invention will be described in detail below through embodiments.

[0116] The content of vinyl structural units, propylene structural units, styrene structural units, butadiene structural units, and isoprene structural units in styrene and conjugated diene block polymers, as well as the bromine content in brominated block polymers, was determined using a Bruker AVANCE 400 superconducting nuclear magnetic resonance spectrometer. 1 H-NMR analysis was performed using a 5 mm diameter sample tube, deuterated chloroform (CDCl3) as the solvent, a 15% (w / v) sample concentration, room temperature, and 16 scans. Calibration was performed with a tetramethylsilane chemical shift of 0 ppm.

[0117] The molecular weights and distributions of styrene, conjugated diene block polymers, and brominated block polymers were determined using an HLC-8320 gel permeation chromatograph from Tosoh Corporation, Japan. The test conditions included: a TSKgel SuperMultipore HZ-N column, a TSKgel SuperMultipore HZ standard column, chromatographically pure THF solvent, polystyrene as the calibration standard, a sample concentration of 1 mg / mL, an injection volume of 10 μL, a flow rate of 0.35 mL / min, and a test temperature of 40 °C.

[0118] The glass transition temperature of the brominated block polymer was determined using a TA-2980DSC differential scanning calorimeter according to the method specified in GB / T29611-2013 Raw Rubber, Glass Transition Temperature, with a heating rate of 20℃ / min.

[0119] The 5wt% thermogravimetric loss of the brominated block polymer was determined using a TA-2980DSC differential scanning calorimeter. The specific procedure was as follows: first, the temperature was raised to 100℃ and held for 5 min, and then the temperature was raised to 600℃ at a rate of 10℃ / min under a nitrogen atmosphere.

[0120] The experimental setup and process are as follows.

[0121] PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block polymer: The experiment was carried out in a 5L polymerization reactor. Solvent, butadiene, isoprene, and styrene monomers were added through the polymerization line. Initiator and structure modifier were added from the top of the polymerization reactor using a syringe. After polymerization, the polymer was condensed with steam and dried in a plasticizer to obtain PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block polymers.

[0122] Brominated block copolymer: The reaction was carried out in a 10L stainless steel reactor lined with polytetrafluoroethylene. The obtained basic block copolymer was redissolved in chloroform. A chloroform solution containing liquid bromine was added dropwise under high-speed stirring. During the addition, a constant temperature water bath was used to maintain the temperature of the reaction system. After the addition was completed, stirring was continued to ensure the reaction proceeded fully. Then, an aqueous solution prepared from deionized water, sodium hydroxide, and sodium sulfite was added and stirred thoroughly. The reaction mixture was allowed to settle, and the aqueous phase and solid residue were separated and removed. The resulting brominated block copolymer solution was repeatedly washed with deionized water until the pH was neutral. Calcium stearate, epoxidized soybean oil, and antioxidants were added. Finally, the solvent was removed and the mixture was dried to obtain the desired product, the brominated block copolymer.

[0123] All pressures mentioned in this experiment refer to gauge pressure.

[0124] Antioxidant 1076 and Antioxidant 1010 were purchased from Inokai Reagents.

[0125] Cyclohexane was purchased from Sinopharm Reagent Company, with a purity >99.9%. It was soaked in a molecular weight sieve for 15 days, and the water content was less than 5 ppm.

[0126] Chloroform, industrial grade, sourced from Yanshan Petrochemical;

[0127] Styrene, polymer grade, sourced from Yanshan Petrochemical;

[0128] Butadiene, polymer grade, sourced from Yanshan Petrochemical;

[0129] n-Butyllithium (Li) was purchased from Bailingwei Reagent Company, 100ml specification, 1.6mol·L⁻¹. -1 Cyclohexane solution, diluted to 0.4 mol·L⁻¹ -1 Cyclohexane solution;

[0130] Diethylene glycol dimethyl ether (2G) was purchased from Inocare Reagents, with a purity >99wt%.

[0131] Bis(dimethylaminoethyl) ether (BDMAEE) was purchased from Inokai Reagents, with a purity >98 wt%.

[0132] The bis(tetrahydrofurfuryl) propane (DTHFP) was purchased from Bailingwei Reagent Company with a purity >98wt%.

[0133] Tetrahydrofurfuryl ethyl ether (ETE) was purchased from Bailingwei Reagent Company, with a purity >98wt%.

[0134] Sodium terpineol (STP) was purchased from Qingkai Huafeng Reagent Company in 1.0 mol / L hexane solution;

[0135] Sodium dodecylbenzenesulfonate (SDBS) was purchased from Bailingwei Reagent Company, with a purity >98wt%.

[0136] Liquid bromine (Br) is sourced from Qingkai Huafeng Reagent Company, with a purity greater than 99%.

[0137] Calcium stearate (Ca) is available from Qingkai Huafeng Reagent Company, industrial grade;

[0138] Epoxidized soybean oil (OA) is available from Qingkai Huafeng Reagent Company, industrial grade;

[0139] Sodium hydroxide (Na) is available from Qingkai Huafeng Reagent Company, industrial grade.

[0140] Example 1

[0141] This embodiment is used to illustrate PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block polymers and their preparation methods.

[0142] S1. Under nitrogen protection, cyclohexane solvent (2300g), composite structure modifier, and styrene monomer 1 (types and amounts are shown in Table 1; all amounts listed in the table are based on pure compounds, the same below) are added to a 5L reactor. The initiation reaction temperature is controlled within the range of 0-50℃ (polymerization temperature and pressure are shown in Table 2, the same below). The designed amount of n-butyllithium is added to the 5L reactor, and the polymerization reaction temperature is controlled within the range of 0-50℃. After 10 minutes, a product containing PS is obtained. 1 Copolymer solutions with structural features;

[0143] S2, Towards PS 1 Isoprene monomer 1 was added to the copolymer solution of the structure, and the polymerization reaction temperature was controlled at 0-50℃. After 30 minutes, a product containing PS was obtained. 1 -HPIR 1 Copolymer solutions with structural features;

[0144] S3, To contain PS 1 -HPIR 1 Butadiene monomer was added to the copolymer solution of the structure, and the polymerization reaction temperature was controlled at 0-50℃. After 30 minutes, a product containing PS was obtained. 1 -HPIR 1 -HVBR structured copolymer solution;

[0145] S4, To contain PS 1 -HPIR 1 The copolymer solution of isoprene monomer 2 with a -HVBR structure was subjected to polymerization at a controlled temperature of 0-50℃ for 20 minutes to obtain a product containing PS. 1 -HPIR 1 -HVBR-HPIR 2 Copolymer solutions with structural features;

[0146] S5, To contain PS 1 -HPIR 1 -HVBR-HPIR 2 Styrene monomer 2 was added to the copolymer solution of the structure, and the polymerization reaction temperature was controlled at 0-50℃. After 10 minutes, a copolymer containing PS was obtained. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Copolymer solutions with structural features;

[0147] S6, To contain PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The copolymer solution of the structure was terminated by adding sufficient deionized water. After complete termination, 1g of antioxidant 1076 was added, followed by coagulation and drying to obtain PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block copolymer P1 was analyzed, and the results are shown in Table 3.

[0148] Example 2-13

[0149] This embodiment is used to illustrate PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block polymers and their preparation methods.

[0150] According to the method described in Example 1, except that the block polymers were prepared using the parameters shown in Tables 1 and 2, thereby obtaining PS respectively. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The analytical results of block polymers P2-P13 are shown in Table 3.

[0151] Comparative Example 1

[0152] The method described in Example 1 is different except that 2G is not added. Specific parameters are shown in Tables 1 and 2, and the PS is obtained. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The analysis results of the block polymer DP1 are shown in Table 3.

[0153] Comparative Example 2

[0154] The method described in Example 1 is different except that DTHFP is not added. Specific parameters are shown in Tables 1 and 2. The reaction is exceptionally slow, yielding PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The block polymer DP2 was analyzed, and the results are shown in Table 3. The residual monomer content of styrene was 8.4 wt%, the residual monomer content of butadiene was 6.5 wt%, and the residual monomer content of isoprene was 13.2 wt%.

[0155] Comparative Example 3

[0156] The method described in Example 1 is different except that STP is not added. Specific parameters are shown in Tables 1 and 2, and PS is obtained. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The analysis results of the block polymer DP3 are shown in Table 3.

[0157] Comparative Example 4

[0158] The method described in Example 1 is different except that the initiation temperature is adjusted. Specific parameters are shown in Tables 1 and 2, and the PS is obtained. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The analysis results of the block polymer DP4 are shown in Table 3.

[0159] Comparative Example 5

[0160] The method described in Example 1 differs in that the amount of styrene monomer used is different. Specific parameters are shown in Tables 1 and 2, resulting in PS... 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The analysis results of the block polymer DP5 are shown in Table 3.

[0161] Table 1

[0162]

[0163]

[0164] Table 1 (continued)

[0165] serial number Styrene 1 / g Isoprene 1 / g butadiene / g Isoprene 2 / g Styrene 2 / g Example 1 56 75 112 75 56 Example 2 56 75 112 75 56 Example 3 56 75 112 75 56 Example 4 56 68 126 68 56 Example 5 56 83 96 83 56 Example 6 48 75 128 75 48 Example 7 64 67 112 67 64 Example 8 45 75 112 75 67 Example 9 56 60 112 90 56 Example 10 56 75 112 75 56 Example 11 56 75 112 75 56 Example 12 56 75 112 75 56 Example 13 56 75 112 75 56 Comparative Example 1 56 75 112 75 56 Comparative Example 2 56 75 112 75 56 Comparative Example 3 56 75 112 75 56 Comparative Example 4 56 75 112 75 56 Comparative Example 5 33 75 158 75 33

[0166] Table 1 (continued)

[0167]

[0168]

[0169] Table 2

[0170]

[0171]

[0172] Table 3

[0173] example <![CDATA[Mn / 10 4 ]]> MWD Bv / % Ia / % St / % Bd / % Ip / % <![CDATA[PS 1 / PS 2 ]]> <![CDATA[HPIR 1 / HPIR 2 ]]> P1 10.5 1.06 88.5 88.3 30.2 29.7 40.1 5 / 5 5 / 5 P2 8.2 1.05 88.3 88.1 30.2 29.8 40.0 5 / 5 5 / 5 P3 13.1 1.07 86.4 86.2 30.1 29.8 40.1 5 / 5 5 / 5 P4 10.4 1.06 86.2 86.3 30.2 33.4 36.4 5 / 5 5 / 5 P5 10.6 1.07 82.8 82.4 30.3 25.4 44.3 5 / 5 5 / 5 P6 10.3 1.07 82.1 82.3 25.9 33.9 40.2 5 / 5 5 / 5 P7 10.7 1.07 85.2 85.4 34.5 29.7 35.8 5 / 5 5 / 5 P8 10.5 1.06 86.3 86.2 30.2 29.7 40.1 4 / 6 5 / 5 P9 10.6 1.08 86.1 86.3 30.1 29.8 40.1 5 / 5 4 / 6 P10 10.5 1.04 80.6 80.5 30.1 29.7 40.2 5 / 5 5 / 5 P11 9.8 1.17 86.8 86.9 30.2 29.7 40.1 5 / 5 5 / 5 P12 10.3 1.15 86.4 86.6 30.1 29.8 40.1 5 / 5 5 / 5 P13 10.5 1.04 82.1 82.4 30.1 29.8 40.1 5 / 5 5 / 5 DP1 10.2 1.05 77.8 77.5 30.1 29.9 40.0 5 / 5 5 / 5 DP2 7.7 1.38 85.3 85.2 30.1 32.6 37.3 5 / 5 5 / 5 DP3 9.8 1.20 79.5 79.3 30.2 29.8 40.0 5 / 5 5 / 5 DP4 10.3 1.07 77.2 77.2 30.2 29.8 40.0 5 / 5 5 / 5 DP5 10.4 1.06 88.3 88.2 17.8 42.1 40.1 5 / 5 5 / 5 SBS1301 11.4 1.04 12.4 0 30.4 69.6 0 5 / 5 5 / 5 SBS1401 8.4 1.04 12.1 0 40.6 59.4 0 5 / 5 5 / 5

[0174] Note: Bv% represents the content of vinyl structural units in high-vinyl polybutadiene block HVBR; Ia% represents HPIR. 1 and HPIR 2 The content of propylene structural units in St% block copolymers; styrene blocks (PS) in St% block copolymers 1 +PS 2 The content of ); Ip% is the content of polyisoprene blocks in the block copolymer; Bd% is the content of polybutadiene blocks in the block copolymer.

[0175] As can be seen from Table 3, the PS prepared by this invention 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block copolymers, with high vinyl content in polybutadiene blocks and propylene group content in polyisoprene blocks, and narrow molecular weight distribution, are particularly suitable as precursors for brominated block polymers for exterior wall insulation.

[0176] Application Example 1

[0177] This application example illustrates the PS prepared according to the present invention. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Application of block copolymers in brominated block copolymers.

[0178] In a 10L stainless steel reactor lined with polytetrafluoroethylene, block copolymer P1 was redissolved in chloroform to obtain a 10% by weight solution. 4000g of a chloroform solution containing 750g of liquid bromine was added dropwise under high-speed stirring. During the addition, the temperature of the reaction system was maintained at 10℃ using a constant-temperature water bath. After the addition was complete, stirring continued for 300 minutes to ensure the reaction proceeded fully. Then, an aqueous solution prepared with 1500g of deionized water, 160g of sodium hydroxide, and 275g of sodium sulfite was added, and the mixture was stirred thoroughly for 20 minutes. The reaction mixture was allowed to settle, and the aqueous phase and solid residue were separated and removed. The resulting brominated block copolymer solution was repeatedly washed with deionized water until the pH was neutral. 11g of calcium stearate, 11g of epoxidized soybean oil, and 1g of antioxidant 1010 were added. Finally, the solvent was removed and the mixture was dried to obtain the desired product, brominated block copolymer XP1. The analytical results are shown in Table 4.

[0179] Application Example 2-13

[0180] PS was prepared using the same method as in Example 1. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The brominated block copolymers were prepared by replacing block copolymer P1 with block copolymer P2-P13. The analytical results are shown in Table 4.

[0181] Compare and contrast examples 1-5

[0182] PS was prepared using the same method as in Example 1. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The brominated block copolymers were prepared by replacing block copolymer P1 with block copolymer DP1-DP5. The results of the analysis are shown in Table 4.

[0183] Compare and contrast examples 6-7

[0184] Brominated block polymers were prepared using the same method as in Application Example 1, except that commercially available SBS grades SBS1301 and SBS1401 were used instead of PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The block polymer P1 was used to prepare brominated block polymers XSBS1301-XSBS1401. The analytical results of SBS1301 and SBS1401 are shown in Table 3, and the analytical test results of XSBS1301-XSBS1401 are shown in Table 4.

[0185] Table 4

[0186] example Number average molecular weight / 10,000 Molecular weight distribution Bromine content / wt% 5wt% thermogravimetric temperature / ℃ Glass transition temperature / °C XP1 11.6 1.08 65.9 264 129 XP2 8.9 1.07 65.8 264 126 XP3 14.4 1.08 65.3 265 131 XP4 11.5 1.07 65.1 265 126 XP5 11.4 1.08 64.2 263 127 XP6 11.2 1.08 65.8 267 123 XP7 11.6 1.09 62.9 261 131 XP8 11.7 1.08 65.0 263 128 XP9 11.5 1.09 64.9 264 128 XP10 11.4 1.07 63.1 260 124 XP11 10.7 1.18 65.2 260 128 XP12 11.1 1.16 65.1 261 128 XP13 11.4 1.06 64.0 262 127 XDP1 11 1.08 61.6 256 124 XDP2 8.5 1.47 62.3 239 120 XDP3 11.1 1.28 62.4 244 124 XDP4 11.3 1.10 60.9 251 123 XDP5 11.4 1.08 66.7 241 117 XSBS1301 11.2 1.07 33.9 228 110 XSBS1401 8.8 1.08 29.8 216 106

[0187] As can be seen from Table 4, by using the PS provided by this invention... 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 Block copolymers can be used as precursors to prepare brominated block copolymers with narrow molecular weight distribution, high bromine content, and high thermal decomposition temperature and glass transition temperature at 5wt%. These brominated block copolymers are particularly suitable as environmentally friendly flame retardants for polystyrene foam exterior wall insulation.

[0188] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A block copolymer, characterized in that, The block copolymer has PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The block structure shown; Among them, PS 1 and PS 2 Each is an independent styrene block, HPIR 1 and HPIR 2 Each is independently a high-propylene-content polyisoprene block, while HVBR is a high-vinyl-content polybutadiene block; Based on the total molar number of HPIR in the block copolymer, it contains at least 80 mol% of propylene structural units; based on the total molar number of HVBR in the block copolymer, it contains at least 80 mol% of vinyl structural units. Based on the total weight of the block copolymer, the content of the styrene block is 20-40 wt%; The block copolymer has a molecular weight distribution of 1-1.2; Based on the total weight of the block copolymer, the content of the high-propylene-content polyisoprene block is 30-50 wt%; Based on the total weight of the block copolymer, the content of the high vinyl content polybutadiene block is 20-40 wt%.

2. The block copolymer according to claim 1, wherein, Based on the total molar number of HPIR in the block copolymer, it contains at least 82 mol% of propylene-based structural units.

3. The block copolymer according to claim 1, wherein, Based on the total molar number of HPIR in the block copolymer, it contains at least 84 mol% of propylene-based structural units.

4. The block copolymer according to claim 1, wherein, Based on the total molar number of HPIR in the block copolymer, it contains at least 86 mol% of propylene-based structural units.

5. The block copolymer according to claim 1, wherein, Based on the total molar number of HVBR in the block copolymer, it contains at least 82 mol% of vinyl structural units.

6. The block copolymer according to claim 1, wherein, Based on the total molar number of HVBR in the block copolymer, it contains at least 84 mol% of vinyl structural units.

7. The block copolymer according to claim 1, wherein, Based on the total molar number of HVBR in the block copolymer, it contains at least 86 mol% of vinyl structural units.

8. The block copolymer according to any one of claims 1-7, wherein, Based on the total weight of the block copolymer, the content of the styrene block is 22-35 wt%.

9. The block copolymer according to any one of claims 1-7, wherein, PS 1 and PS 2 The weight ratio is 3 / 7-7 / 3.

10. The block copolymer according to any one of claims 1-7, wherein, PS 1 and PS 2 The weight ratio is 4 / 6-6 / 4.

11. The block copolymer according to any one of claims 1-7, wherein, Based on the total weight of the block copolymer, the content of the high-propylene-content polyisoprene block is 35-45 wt%; And / or, HPIR 1 and HPIR 2 The weight ratio is 4 / 6-6 / 4.

12. The block copolymer according to any one of claims 1-7, wherein, Based on the total weight of the block copolymer, the content of the high vinyl content polybutadiene block is 25-35 wt%.

13. The block copolymer according to any one of claims 1-7, wherein, The number average molecular weight of the block copolymer is 50,000-200,000.

14. The block copolymer according to any one of claims 1-7, wherein, The number average molecular weight of the block copolymer is 80,000-150,000.

15. The block copolymer according to any one of claims 1-7, wherein, The block copolymer has a molecular weight distribution of 1.01-1.

15.

16. The block copolymer according to any one of claims 1-7, wherein, The block copolymer has a molecular weight distribution of 1.02-1.

1.

17. A method for preparing the block copolymer according to any one of claims 1-16, characterized in that, The preparation method includes the following steps: (1) In a nonpolar hydrocarbon solvent, in the presence of a composite structure modifier and an initiator, styrene monomer 1 undergoes a first anionic polymerization reaction to obtain a product containing PS. 1 Polymer solutions with a specific structure; (2) To the substance containing PS 1 Isoprene monomer 1 was added to the polymer solution, and a second anionic solution polymerization was carried out to obtain a product containing PS. 1 -HPIR 1 Copolymer solutions with structural features; (3) To the substance containing PS 1 -HPIR 1 Butadiene monomer is added to the copolymer solution of the structure, and a third anionic polymerization reaction is carried out to obtain a product containing PS. 1 -HPIR 1 -HVBR structured copolymer solution; (4) To the substance containing PS 1 -HPIR 1 Isoprene monomer 2 was added to a copolymer solution with a -HVBR structure, and a fourth anionic polymerization reaction was carried out to obtain a product containing PS. 1 -HPIR 1 -HVBR-HPIR 2 Copolymer solutions with structural features; (5) To the substance containing PS 1 -HPIR 1 -HVBR-HPIR 2 Styrene monomer 2 was added to the copolymer solution of the structure, and the fifth anionic polymerization reaction was carried out to obtain a product containing PS. 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The copolymer solution with the structure, for the PS-containing 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The copolymer solution of the structure is dried to obtain the block copolymer; The composite structure modifier comprises component A, component B, and component C. Component A is a polar ether compound and / or a polar amine compound, component B is a polar ether compound and / or a polar amine compound, and component C is selected from at least one of sodium alkoxide, potassium alkoxide, sodium alkylbenzene sulfonate, and potassium alkylbenzene sulfonate. The polymerization temperatures of the first anionic polymerization reaction, the second anionic polymerization reaction, the third anionic polymerization reaction, the fourth anionic polymerization reaction, and the fifth anionic polymerization reaction are each independently 0-50℃; Based on the total weight of styrene monomer, isoprene monomer, and butadiene monomer, the amount of styrene monomer used is 20-40 wt%; Component A has the structure shown in Formula I; Equation I; Where Q1, Q2 and Q3 are each independently N or O, n1 is an integer from 2 to 6, m is 0 or 1, r is 0 or 1, n2 is an integer from 0 to 4, and q1 and q2 are each independently 1 or 2; Component B has the structure shown in Formula II; Formula II; Wherein, R1 and R2 are each independently H or CH3, and R3 is a C2-C6 alkoxy group. or .

18. The preparation method according to claim 17, wherein, Component A is selected from at least one of diethylene glycol dimethyl ether, tetramethylethylenediamine, pentamethyldivinyltriamine, and dimethylaminoethyl ether.

19. The preparation method according to claim 17, wherein, Component A is diethylene glycol dimethyl ether and / or bis(dimethylaminoethyl) ether.

20. The preparation method according to any one of claims 17-19, wherein, Component B is selected from at least one of bis(tetrahydrofurfuryl)propane, tetrahydrofurfuryl ethyl ether, and N,N-dimethyltetrahydrofurfurylamine.

21. The preparation method according to any one of claims 17-19, wherein, Component C is selected from sodium alkoxide and / or sodium alkylbenzene sulfonate.

22. The preparation method according to any one of claims 17-19, wherein, Component C is selected from at least one of sodium terpineol, sodium menthol, and sodium dodecylbenzenesulfonate.

23. The preparation method according to any one of claims 17-19, wherein, The amount of component A is 0.2-0.8 mol relative to 1 mol of initiator, the amount of component B is 0.5-3 mol, and the amount of component C is 0.03-0.1 mol.

24. The preparation method according to any one of claims 17-19, wherein, The amount of component A is 0.3-0.6 mol relative to 1 mol of initiator, the amount of component B is 0.8-2 mol, and the amount of component C is 0.04-0.08 mol.

25. The preparation method according to any one of claims 17-19, wherein, The polymerization temperatures of the first anionic polymerization reaction, the second anionic polymerization reaction, the third anionic polymerization reaction, the fourth anionic polymerization reaction, and the fifth anionic polymerization reaction are each independently 0-40℃.

26. The preparation method according to any one of claims 17-19, wherein, Based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of styrene monomer used is 22-35 wt%.

27. The preparation method according to any one of claims 17-19, wherein, The weight ratio of styrene monomer 1 to styrene monomer 2 is 3 / 7 to 7 / 3.

28. The preparation method according to any one of claims 17-19, wherein, The weight ratio of styrene monomer 1 to styrene monomer 2 is 4 / 6 to 6 / 4.

29. The preparation method according to any one of claims 17-19, wherein, Based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of isoprene monomer used is 30-50 wt%.

30. The preparation method according to any one of claims 17-19, wherein, Based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of isoprene monomer used is 35-45 wt%.

31. The preparation method according to any one of claims 17-19, wherein, The weight ratio of isoprene monomer 1 to isoprene monomer 2 is 4 / 6 to 6 / 4.

32. The preparation method according to any one of claims 17-19, wherein, Based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of butadiene monomer used is 20-40 wt%.

33. The preparation method according to any one of claims 17-19, wherein, Based on the total weight of styrene monomer, isoprene monomer and butadiene monomer, the amount of butadiene monomer used is 25-35 wt%.

34. The preparation method according to any one of claims 17-19, wherein, The preparation method further includes: processing the PS 1 -HPIR 1 -HVBR-HPIR 2 -PS 2 The reaction is terminated by a block copolymer solution with a specific structure.

35. The preparation method according to claim 34, wherein, The terminator in the termination reaction is deionized water.

36. A block copolymer prepared by the method according to any one of claims 17-35.

37. A brominated block copolymer, characterized in that, The brominated block copolymer is obtained by bromination of the block copolymer according to any one of claims 1-16 and 36.

38. The brominated block copolymer according to claim 37, wherein, Based on the total weight of the brominated block copolymer, the bromine content is 60-68 wt%.

39. The brominated block copolymer according to claim 37, wherein, Based on the total weight of the brominated block copolymer, the bromine content is 61-67 wt%.

40. The brominated block copolymer according to claim 37, wherein, Based on the total weight of the brominated block copolymer, the bromine content is 62-66 wt%.

41. The brominated block copolymer according to any one of claims 37-40, wherein, The number-average molecular weight of the brominated block copolymer is 50,000-200,000.

42. The brominated block copolymer according to any one of claims 37-40, wherein, The number-average molecular weight of the brominated block copolymer is 80,000-150,000.

43. The brominated block copolymer according to any one of claims 37-40, wherein, The brominated block copolymer has a molecular weight distribution of 1-1.

2.

44. The brominated block copolymer according to any one of claims 37-40, wherein, The brominated block copolymer has a molecular weight distribution of 1.01-1.

15.

45. The brominated block copolymer according to any one of claims 37-40, wherein, The molecular weight distribution of the brominated block copolymer is 1.02-1.

1.

46. ​​The brominated block copolymer according to any one of claims 37-40, wherein, The 5wt% thermogravimetric temperature of the brominated block copolymer is greater than or equal to 260°C.

47. The brominated block copolymer according to any one of claims 37-40, wherein, The 5wt% thermogravimetric temperature of the brominated block copolymer is 260-268℃.

48. The brominated block copolymer according to any one of claims 37-40, wherein, The 5wt% thermogravimetric temperature of the brominated block copolymer is 261-267℃.

49. The brominated block copolymer according to any one of claims 37-40, wherein, The glass transition temperature of the brominated block copolymer is greater than or equal to 120°C.

50. The brominated block copolymer according to any one of claims 37-40, wherein, The glass transition temperature of the brominated block copolymer is 121-133℃.

51. The brominated block copolymer according to any one of claims 37-40, wherein, The glass transition temperature of the brominated block copolymer is 123-131℃.

52. The application of the brominated block copolymer according to any one of claims 37-51 in exterior wall insulation flame retardants.

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