CN108102053A - The brominated segmented copolymer fire retardant of intermediate molecular weight and its two one-step preparation method of lotion - Google Patents

Abstract

The invention discloses a two-step preparation method for an emulsion of a medium molecular weight (polymerization degree: 80-582) bromine-containing multi-block copolymer flame retardant: it is prepared by a reversible addition-fragmentation chain transfer polymerization method, and bromine-containing styrene And/or bromine-containing acrylates and diolefins are polymerized monomers, azo compounds or organic peroxides are used as initiators, trithioester derivatives are used as chain transfer agents, and medium molecular weight brominated styrene/ Acrylate-diene-styrene/acrylate triblock copolymer; after bromination of the copolymer with a brominating agent, a medium molecular weight bromine-containing multi-block copolymer flame retardant is obtained, that is, a medium molecular weight brominated styrene/ Acrylates-diene-styrene/acrylate triblock copolymer brominated flame retardant. The flame retardant has high bromine content and good flame retardant effect.

Description

Medium molecular weight bromine-containing multi-block copolymer flame retardant and two-step preparation method of its emulsion

technical field

The invention relates to the field of polymer flame retardants, in particular to a brominated medium molecular weight styrene-diene-styrene triblock copolymer flame retardant and a preparation method thereof.

Background technique

Brominated flame retardants can meet the flame retardant requirements of various polymer materials due to their high flame retardant efficiency and good thermal stability, and their raw materials are abundant and cheap. They are currently the most widely used flame retardants in the market. One of the fuels. However, the currently commonly used small molecule brominated flame retardants (molecular weight less than 500, such as polybrominated diphenyl ethers, etc.) usually have the disadvantage of being easily precipitated from the polymer material matrix, and they will produce carcinogens such as dioxins when burned, resulting in Environmental problems, and the long-chain structure of polymer brominated flame retardants make it difficult to migrate, which can be better applied to the flame retardancy of polymer materials, and is green and environmentally friendly.

The effect of polymer flame retardants is better than that of small molecule flame retardants. At present, the commonly used polymer brominated flame retardants mainly include polybrominated styrene PBS (or brominated polystyrene BPS), brominated epoxy resin BEP, bromine Polycarbonate BCO and brominated polystyrene-butadiene-styrene copolymer Br-SBS, PBS and Br-SBS with higher bromine content. Among them, the rigid aromatic segment in PBS reduces the toughness of the material when it is compounded with the substrate, while the introduction of linear butadiene segment in Br-SBS can increase the toughness of the material. However, the current commercially available Br-SBS flame retardant has a molecular weight of more than 100,000. It is obtained by bromination on high-molecular-weight SBS obtained by anionic polymerization, which makes it difficult to disperse in polymer materials, and the bromination reaction is difficult. As a result, the bromine content is not high, and the addition amount is large when used, which affects the flame retardant effect.

Patent CN104327214A reports a method for preparing brominated flame retardants by bromination of commercially available SBS products. The bromine content is 65-70%. dispersed in the matrix.

Patent CN102504067A reports that traditional free radical polymerization of styrene is used to obtain polystyrene PS with molecular weights of 10650 and 33500, and then brominated to obtain brominated flame retardants with bromine contents of 68.1% and 68.22%, respectively.

Patent CN101824113A reports that polystyrene with a molecular weight of 5000 is prepared by anionic polymerization, and then brominated to obtain a flame retardant with a bromine content of 69%.

Patent CN103923239A reports that anionic polymerization is used to prepare polystyrene PS with a molecular weight of 958-8100, and then brominated to obtain a flame retardant with a bromine content of 68.3-78.7%.

The above-mentioned high molecular weight brominated PS and brominated SBS have low bromine content, while the medium and low molecular weight brominated PS have a single molecular chain structure and do not have a multi-block structure.

Contents of the invention

The technical problem to be solved by the present invention is to provide a brominated styrene/acrylate-diene-styrene/acrylate triblock copolymer with a high bromine content (about 70.2 to 74.8 wt%) and a medium molecular weight. Combustion agent and its preparation method.

In order to solve the above technical problems, the present invention provides a two-step preparation method for the emulsion of a medium molecular weight (polymerization degree: 80-582) bromine-containing multi-block copolymer flame retardant: using reversible addition-fragmentation chain transfer (RAFT) polymerization The method is prepared by using bromine-containing styrene and/or bromine-containing acrylate and diene as polymerization monomer, azo compound or organic peroxide as initiator, trithioester derivative as chain transfer agent, and polymerizing by two-step method A medium molecular weight brominated styrene/acrylate-diene-styrene/acrylate triblock copolymer is obtained; after the copolymer is brominated with a brominating agent, a medium molecular weight (polymerization degree of 80-582) bromine-containing polyblock copolymer is obtained. Segment copolymer flame retardants, namely, medium molecular weight brominated styrene/acrylate-diene-styrene/acrylate triblock copolymer brominated flame retardants.

As the improvement of the emulsion two-step preparation method of the medium molecular weight bromine-containing multi-block copolymer flame retardant of the present invention, the two-step method polymerization is to carry out the following steps in sequence:

1) Stir H ₂ O as a solvent, 3.76-7.8 parts of emulsifier, 5-100 parts of diene, and 0.5-5.0 parts of trithioester derivative as chain transfer agent, and then protect it under inert gas (nitrogen) , heat up to 50-80°C, add 0.01-0.1 part of azo compound or organic peroxide as an initiator and keep it warm for 2-10 hours to obtain a diene homopolymer;

2) Add 30-130 parts of bromine-containing styrene and/or bromine-containing acrylate to the reactor after the reaction in step 1) under the protection of an inert gas, and react at 50-80°C for 2-10 hours; to obtain a medium molecular weight Brominated styrene/acrylate-diene-brominated styrene/acrylate triblock copolymer;

The above parts are parts by weight.

In the above step 1), the amount of H ₂ O used as a solvent is 100-200 parts.

As the further improvement of the emulsion two-step preparation method of the medium molecular weight bromine-containing multi-block copolymer flame retardant of the present invention:

The bromostyrene is at least one of 2,4,6-tribromostyrene and pentabromostyrene;

The bromine-containing acrylate is at least one of 2,4,6-tribromophenyl acrylate, 2,4,6-tribromophenyl methacrylate, and pentabromobenzyl acrylate;

The diene is one of 1,4-butadiene and isoprene.

As the further improvement of the emulsion two-step preparation method of the medium molecular weight bromine-containing multi-block copolymer flame retardant of the present invention:

The described azo compound as initiator is azobisisobutyronitrile (AIBN), azobisisoheptanonitrile (ABVN), azobisisobutylamidine hydrochloride (AIBA), azobisisobutylimidazoline Hydrochloride (AIBI) or azoisobutylcyanoformamide (V30);

The described organic peroxide as initiator is dibenzoyl peroxide (BPO), benzoyl tert-butyl peroxide, ammonium persulfate (APS), potassium persulfate (KPS);

Trithioester derivatives as chain transfer agents are bis(α,α'-dimethyl-α"-acetate) trithiocarbonate, bis(α,α'-dimethyl-α" trithiocarbonate -pentanoate), bis(α,α'-diethyl-α"-acetate) trithiocarbonate.

As the further improvement of the emulsion two-step preparation method of the medium molecular weight bromine-containing multi-block copolymer flame retardant of the present invention:

The emulsifier is at least one of sodium lauryl sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene sorbitan fatty acid ester T-80, and OP-10.

As the further improvement of the emulsion two-step preparation method of the medium molecular weight bromine-containing multi-block copolymer flame retardant of the present invention:

In said step 3), after the reaction finishes (cooling terminates the reaction), the product is freeze-dried to constant weight to obtain a medium molecular weight brominated styrene/acrylate-diene-brominated styrene/acrylate triblock copolymer .

As a further improvement of the emulsion two-step preparation method of the medium molecular weight bromine-containing multi-block copolymer flame retardant of the present invention, the bromination process is:

Add 5 to 10 times the mass of isobutanol to the medium molecular weight brominated styrene/acrylate-diene-brominated styrene/acrylate triblock copolymer and raise the temperature to 30-70°C to dissolve the copolymer. Add bromination agent 1 to 15 times the mass of the copolymer under heat preservation conditions and stir for 1 to 15 hours. After the reaction, precipitate with methanol, filter, and vacuum dry to constant weight to obtain a medium molecular weight bromine-containing multi-block copolymer flame retardant.

As a further improvement of the two-step preparation method of the emulsion of the medium molecular weight brominated multi-block copolymer flame retardant of the present invention, the brominated agent is bromine chloride or tetraethylammonium bromide.

The present invention also provides a medium molecular weight bromine-containing multi-block copolymer flame retardant prepared by the above method at the same time, the degree of polymerization is between 80 and 582, and its molecular weight is easily passed through the Esters, 1,4-butadiene/isoprene) additions are regulated.

As an improvement of the medium-molecular-weight bromine-containing multi-block copolymer flame retardant of the present invention: the bromine content is 70.2-74.8 wt%, and the bromine content can be adjusted by the amount of brominating agent.

In the present invention, the reversible addition-fragmentation chain transfer (RAFT) polymerization method in living/controlled radical polymerization is used to obtain bromine-containing styrene or bromine-containing acrylate, 1,4-butadiene or isoprene Diolefins are polymerized monomers, and medium molecular weight styrene-diene-styrene triblock copolymers are prepared by adding in two batches.

The styrene-diene-styrene triblock copolymer of the present invention adopts the RAFT polymerization method, and can regulate and form products with different middle molecular weights by controlling the degree of polymerization, thereby enhancing the compatibility with the resin matrix. In addition, the bromination method provided in the present invention makes the three-block structure chemically combine a high content of bromine, and the flame retardant efficiency per unit mass of the flame retardant will be improved.

The present invention combines the advantages of RAFT polymerization and the bromination process to prepare a medium molecular weight brominated styrene/acrylate-diene-styrene/acrylate triblock copolymer brominated flame retardant, controlling the monomer and bromination agent Brominated flame retardant products with different medium molecular weight, different three-block structure and different bromine content can be obtained.

In the present invention, because of the introduction of butadiene/isoprene segment, the scope of application of triblock copolymer is wider than brominated PS and can improve the mechanical property of material, so the present invention selects block structure for use; The existing polymer brominated flame retardants have the problems of difficult dispersion and insufficient bromine content, so the present invention uses medium molecular weight and multi-block structure to solve this problem.

Compared with the existing flame retardants such as brominated polystyrene with medium molecular weight, the tri-block copolymer of the present invention uses monomers for living polymerization, and while maintaining medium molecular weight, it increases the ratio of butadiene/isoprene The soft segment becomes a multi-block structure, which is suitable for different systems and has a good flame retardant effect; compared with high molecular weight brominated PS and brominated SBS, the molecular weight of the triblock copolymer brominated flame retardant of the present invention is slightly lower, It is easy to control the uniform dispersion in different matrices, not easy to precipitate, and has high bromine content and good flame retardant effect.

The tri-block copolymer flame retardant of the present invention has the characteristics of medium molecular weight, high bromine content, and block structure; compared with existing high molecular weight flame retardants (brominated PS, brominated SBS, etc.), the present invention has The characteristics of low molecular weight and high bromine content are easy to disperse; compared with the existing medium molecular weight PS, the present invention has the characteristics of multi-block structure.

In summary, the present invention uses bromine-containing styrene, bromine-containing acrylate, 1,4-butadiene/isoprene as polymerization monomers, azo compounds or organic peroxides as initiators, trithioester Derivatives are used as chain transfer agents to prepare mid-molecular weight brominated styrene/acrylate-diene-styrene/acrylate ternites with controlled molecular weight by emulsion polymerization using the reversible addition-fragmentation chain transfer (RAFT) polymerization method segment copolymers. The copolymer is brominated by a brominating agent to obtain a highly efficient flame retardant with high bromine content and good stability, which can be used as a flame retardant for polystyrene, polyester, polyamide, etc., and is compatible with the substrate Good sex. Brominated polymer flame retardants with different molecular weights and bromine contents can be obtained by controlling the quality of monomers and brominating agents.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited thereto.

Embodiment 1, a kind of preparation method of medium molecular weight brominated polymer flame retardant:

1. With 2,4,6-tribromostyrene, pentabromostyrene and 1,4-butadiene as polymerization monomers, azobisisobutyronitrile (AIBN) as initiator, trithiocarbonic acid bis( α,α'-Dimethyl-α”-acetic acid) ester is used as chain transfer agent, sodium lauryl sulfate is used as emulsifier, and medium molecular weight brominated styrene-butadiene-benzene bromide is obtained by two-step polymerization Ethylene triblock copolymer, the steps are as follows:

(1) Add 150 grams of H ₂ O and 7.8 grams of sodium lauryl sulfate into the reaction kettle, stir well and add 65 grams of 1,4-butadiene, 5 grams of trithiocarbonic acid bis(α,α'-Dimethyl-α"-acetic acid) ester, under the protection of nitrogen, heat up to 60°C, add 0.1 g of azobisisobutyronitrile (AIBN) and keep it warm for 2 hours to obtain a homopolymer of butadiene with a degree of polymerization of 63 thing;

(2) Under the protection of nitrogen, add 80 grams of tribromostyrene and 50 grams of pentabromostyrene into the above reaction kettle, and react at 60 ° C for 2 hours; after the reaction time is up, the temperature is lowered to terminate the reaction, and the product is frozen (- 30° C.) and dried to constant weight to obtain a brominated styrene-butadiene-brominated styrene triblock copolymer with a degree of polymerization of 80. The molecular weight is 9989.

Two, the obtained copolymer makes a kind of brominated flame retardant after the bromination agent bromination, the steps are as follows:

Add the brominated styrene-butadiene-brominated styrene triblock copolymer prepared above into the reaction vessel, dissolve it with 5 times the mass of isobutanol, keep the temperature at 40°C, add 2 mass times Bromine chloride was stirred and reacted for 2 hours. After the reaction, it was precipitated and filtered with 500 mL of methanol. The resulting filter cake was dried in a vacuum oven at 40°C to constant weight to obtain a brominated flame retardant. After burning in an oxygen bottle, the bromine content was determined to be 70.2 by ion chromatography. %.

Embodiment 2, a kind of preparation method of medium molecular weight brominated polymer flame retardant:

1. Using pentabromobenzyl acrylate and isoprene as polymerization monomers, azobisisobutylimidazoline hydrochloride (AIBI) as initiator, trithiocarbonic acid bis(α,α'-dimethyl- α”-Acetate) is used as chain transfer agent, sodium dodecylbenzenesulfonate is used as emulsifier, and medium molecular weight brominated acrylate-isoprene-brominated acrylate triblock copolymer is obtained by two-step polymerization ,Proceed as follows:

(1) Add 150 grams of H ₂ O and 3.76 grams of sodium dodecylbenzenesulfonate into the reaction kettle, stir well and add 48 grams of isoprene, 1.0 grams of trithiocarbonic acid bis(α,α'- Dimethyl-α"-acetic acid) ester, under the protection of nitrogen, the temperature was raised to 65°C, and 0.02 g of azobisisobutylimidazoline hydrochloride (AIBI) was added to react for 4 hours to obtain isoprene with a degree of polymerization of 184 olefin homopolymer;

(2) Under the protection of nitrogen, add 46 grams of pentabromobenzyl acrylate into the above reaction kettle, and react at 65°C for 4 hours; after the reaction time is up, the temperature is lowered to terminate the reaction, and the product is freeze-dried to constant weight to obtain the degree of polymerization 205 brominated acrylate-isoprene-brominated acrylate triblock copolymer. The molecular weight is 24209.

Two, the obtained copolymer makes a kind of brominated flame retardant after the bromination agent bromination, the steps are as follows:

Add the brominated acrylate-isoprene-brominated acrylate triblock copolymer prepared above into the reaction vessel, dissolve it with 6 times the mass of isobutanol, keep the temperature at 45°C, add 4 mass times tetraethylammonium bromide and stirred for 4 hours. After the reaction, it was precipitated with 500mL of methanol and filtered. The resulting filter cake was dried in a vacuum oven at 45°C to constant weight to obtain a brominated flame retardant with a bromine content of 71.1%.

Embodiment 3, a kind of preparation method of medium molecular weight brominated polymer flame retardant:

1. Using pentabromobenzyl acrylate, pentabromostyrene and 1,4-butadiene as polymerization monomers, azoisobutyrocyanoformamide (V30) as initiator, bis(α,α) trithiocarbonate '-Dimethyl-α"-valeric acid) ester is used as chain transfer agent, polyoxyethylene sorbitan fatty acid ester T-80 is used as emulsifier, and medium molecular weight brominated styrene-butanediene is obtained by two-step polymerization Alkene-brominated acrylate triblock copolymer, the steps are as follows:

(1) Add 150 grams of H ₂ O and 5.2 grams of polyoxyethylene sorbitan fatty acid ester T-80 into the reaction kettle, stir well and add 45 grams of 1,4-butadiene, 0.8 grams of trithio Bis(α,α'-dimethyl-α"-valeric acid) carbonate, under the protection of nitrogen, heated up to 70°C, added 0.016 g of azoisobutylcyanoformamide (V30) and incubated for 6 hours to obtain Butadiene homopolymer with a degree of polymerization of 271;

(2) Under the protection of nitrogen, add 40 grams of pentabromostyrene and 45 grams of pentabromobenzyl acrylate into the above reaction kettle, and react at 70°C for 6 hours; after the reaction time is up, cool down to terminate the reaction, and the product is freeze-dried To a constant weight, a brominated styrene-butadiene-brominated acrylate triblock copolymer with a degree of polymerization of 323 was obtained. The molecular weight is 42090.

Two, the obtained copolymer makes a kind of brominated flame retardant after the bromination agent bromination, the steps are as follows:

Add the brominated styrene-butadiene-brominated acrylate triblock copolymer prepared above into the reaction vessel, dissolve it with 7 mass times of isobutanol, keep the temperature at 50°C, and add 6 mass times Bromine chloride was stirred and reacted for 6 hours. After the reaction, 500 mL of methanol was used to precipitate and filter, and the resulting filter cake was dried in a vacuum oven at 50°C to constant weight to obtain a brominated flame retardant with a bromine content of 72.5%.

Embodiment 4, a kind of preparation method of medium molecular weight brominated polymer flame retardant:

1. With 2,4,6-tribromophenyl methacrylate, 2,4,6-tribromostyrene and 1,4-butadiene as polymerized monomers, dibenzoyl peroxide (BPO) is Initiator, bis(α,α'-dimethyl-α”-valeric acid) trithiocarbonate as chain transfer agent, OP-10 as emulsifier, and medium molecular weight brominated acrylate- Butadiene-brominated styrene triblock copolymer, the steps are as follows:

(1) Add 150 grams of H ₂ O and 6.6 grams of OP-10 into the reaction kettle, stir evenly and add 85 grams of 1,4-butadiene, 0.8 grams of trithiocarbonic acid bis(α,α'-dimethyl Base-α"-valeric acid) ester, under the protection of nitrogen, the temperature was raised to 75°C, and 0.016 g of dibenzoyl peroxide (BPO) was added to insulate and react for 8 hours to obtain a butadiene homopolymer with a degree of polymerization of 512;

(2) Under the protection of nitrogen, add 45 grams of 2,4,6-tribromophenyl methacrylate and 35 grams of 2,4,6-tribromostyrene into the above reaction kettle, and react at 75°C for 8 hours After the reaction time is up, the temperature is lowered to terminate the reaction, and the product is freeze-dried to a constant weight to obtain a brominated acrylate-butadiene-brominated styrene triblock copolymer with a degree of polymerization of 582. The molecular weight is 53664.

Two, the obtained copolymer makes a kind of brominated flame retardant after the bromination agent bromination, the steps are as follows:

Add the brominated acrylate-butadiene-brominated styrene triblock copolymer prepared above into the reaction vessel, dissolve it with 8 mass times of isobutanol, keep the temperature at 55°C, add 8 mass times The tetraethylammonium bromide was stirred and reacted for 8 hours. After the reaction was completed, it was precipitated with 500mL of methanol and filtered. The obtained filter cake was dried in a vacuum oven at 55°C to constant weight to obtain a brominated flame retardant with a bromine content of 73.6%.

Embodiment 5, a kind of preparation method of medium molecular weight brominated polymer flame retardant:

1. Pentabromostyrene and isoprene are used as polymerized monomers, potassium persulfate (KPS) is used as an initiator, and bis(α,α'-diethyl-α”-acetic acid) trithiocarbonate is used as a chain Transfer agent, sodium lauryl sulfate is emulsifying agent, obtains medium molecular weight brominated styrene-isoprene-brominated styrene triblock copolymer by two-step method polymerization, and step is as follows:

(1) Add 150 grams of H ₂ O and 4.08 grams of sodium lauryl sulfate into the reaction kettle, stir evenly and add 5 grams of isoprene, 0.6 grams of trithiocarbonic acid bis(α,α'-diethyl Base-α"-acetic acid) ester, under the protection of nitrogen, the temperature was raised to 80°C, and 0.012 g of potassium persulfate (KPS) was added to insulate and react for 10 hours to obtain an isoprene homopolymer with a degree of polymerization of 24;

(2), under the protection of nitrogen, add 97 grams of pentabromostyrene into the above-mentioned reaction kettle, and react at 80°C for 10h; 87 brominated styrene-isoprene-brominated styrene triblock copolymer. The molecular weight is 33568.

Two, the obtained copolymer makes a kind of brominated flame retardant after the bromination agent bromination, the steps are as follows:

Add the brominated styrene-isoprene-brominated styrene triblock copolymer prepared above into the reaction vessel, and dissolve it with 10 times the mass of isobutanol, keep the temperature at 60°C, add 10 mass Double bromine chloride was stirred and reacted for 10 hours. After the reaction was completed, it was precipitated with 500 mL of methanol and filtered. The resulting filter cake was dried in a vacuum oven at 60°C to constant weight to obtain a brominated flame retardant with a bromine content of 74.8%.

A summary of the process parameters of the above-mentioned Examples 1 to 5 is shown in Table 1 below.

Table 1

experiment one,

The brominated flame retardant prepared by the present invention is compounded with polystyrene (PS), polyester and polyamide substrates, tested according to the UL94 standard to reach the minimum addition amount of V-0, and flame-retardant with brominated PS (Albemarle, HP 7010, molecular weight 600,000), Br-SBS flame retardant (Great Lakes, Emerald 3000, molecular weight 100,000), brominated PS flame retardant (brominated PS, American Ferro company, model PB68, molecular weight 15000 ), Br-SBS flame retardant (ICL, FR122P, molecular weight 100,000) for comparison, the results are as follows in Table 2:

Table 2

Compared with commercially available polymer brominated flame retardant products (comparison results are shown in Table 2), the flame retardant provided by the present invention has the advantages of high bromine content and less added amount.

Experiment two,

17 parts of flame retardants of Examples 1 to 5, 4.5 parts of Sb2O3 and 78.5 parts of ABS compounded, tested its Izod notched impact performance according to standard ASTMD256, and with the brominated polystyrene flame retardant ( Br-PS, CN103923239A, molecular weight is 958 ~ 8100, bromine content is 68.3 ~ 78.7%) comparison, the results are as follows in Table 3:

table 3

Compared with brominated polystyrene Br-PS with a single structure (comparison results are shown in Table 3), the flame retardant provided by the present invention has a multi-block structure, which increases the toughness of the material.

Comparative example 1-1,

Change the potassium persulfate (KPS) in Example 5 step 1) from 0.012 grams to 0.0032 grams, and change the amount of bis(α, α'-diethyl-α"-acetic acid) trithiocarbonate from 0.6 grams Change it to 0.16g, and the reaction time is 12h; the rest is the same as in Example 1.

The degree of polymerization of the obtained copolymer was 435. The molecular weight is 167840.

Comparative example 1-2,

Change the potassium persulfate (KPS) in Example 5 step 1) from 0.012 grams to 0.0016 grams, and change the amount of bis (α, α'-diethyl-α "-acetic acid) trithiocarbonate from 0.6 grams Change it to 0.08 g, and the reaction time is 20 h; the rest is the same as in Example 1. The degree of polymerization of the obtained copolymer is 870. The molecular weight is 335680.

All the above-mentioned comparative examples were tested according to the method described in the above-mentioned experiment 1, and the obtained results are shown in Table 4 below.

Table 4

Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (10)

1. two one-step preparation method of lotion of the brominated segmented copolymer fire retardant of intermediate molecular weight, it is characterised in that：Added using reversible Into-fracture chain transfer polymerization method preparation, to contain bromstyrol and/or brominated acrylate, diolefin as polymerized monomer, azo Compound or organic peroxide are initiator, and three thioes derivatives polymerize to obtain medium as chain-transferring agent by two step method Molecular weight brominated phenylethylene ethylene/propenoic acid ester-diolefin-phenylethylene ethylene/propenoic acid ester triblock copolymer；Copolymer is through bromating agent bromine After change, the brominated segmented copolymer fire retardant of intermediate molecular weight is obtained.

2. two one-step preparation method of lotion of the brominated segmented copolymer fire retardant of intermediate molecular weight according to claim 1, It is characterized in that, the two step method is polymerized to follow the steps below successively：

It 1), will be as the H of solvent₂O, 3.76~7.8 parts of emulsifiers, 5~100 parts of diolefins, 0.5~5.0 part is used as chain-transferring agent Three thioes derivatives stir evenly after, under inert gas shielding, be warming up to 50~80 DEG C, add in 0.01~0.1 part of conduct After 2~10h of azo-compound or organic peroxide insulation reaction of initiator, diolefin homopolymer is obtained；

2), added in step 1) reaction kettle after reaction under inert gas shielding 30~130 parts containing bromstyrol and/ Or brominated acrylate, 2~10h is reacted at 50~80 DEG C；Obtain intermediate molecular weight brominated styrene/acrylate-diene Hydrocarbon-brominated styrene/acrylate triblock copolymer；

More than part is parts by weight.

3. two one-step preparation method of lotion of the brominated segmented copolymer fire retardant of intermediate molecular weight according to claim 2, It is characterized in that：

The bromstyrol that contains is at least one of 2,4,6- phenylstilbene bromide, pentabromo- styrene；

The brominated acrylate is 2,4,6- tribromophenyl acrylates, 2,4,6- methacrylic acids tribromophenyl, acrylic acid five At least one of bromobenzyl ester；

The diolefin is 1,4- butadiene, one kind in isoprene.

4. two one-step preparation method of lotion of the brominated segmented copolymer fire retardant of intermediate molecular weight according to claim 3, It is characterized in that：

The azo-compound as initiator is azodiisobutyronitrile, azobisisoheptonitrile, azo-bis-isobutyrate hydrochloride, Two isobutyl imidazoline hydrochloride of azo or azo isobutyl cyano formamide；

The organic peroxide as initiator for dibenzoyl peroxide, the benzoyl peroxide tert-butyl ester, ammonium persulfate, Potassium peroxydisulfate；

Three thioes derivatives as chain-transferring agent are double (α, the α '-dimethyl-α "-acetic acid) ester of trithiocarbonic acid, three thio carbon Double (α, the α '-diethyl-α "-acetic acid) esters of sour double (α, α '-dimethyl-α "-valeric acid) ester, trithiocarbonic acid.

5. two one-step preparation method of lotion of the brominated segmented copolymer fire retardant of intermediate molecular weight according to claim 4, It is characterized in that：

The emulsifier is lauryl sodium sulfate, neopelex, polyoxyethylene sorbitan fatty acid ester T- 80th, at least one of OP-10.

6. two one-step preparation method of lotion of the brominated segmented copolymer fire retardant of intermediate molecular weight according to claim 2, It is characterized in that：

In the step 3), after reaction, product is freeze-dried to constant weight, obtains intermediate molecular weight brominated styrene/the third Olefin(e) acid ester-diolefin-brominated styrene/acrylate triblock copolymer.

7. according to the two step system of lotion of any brominated segmented copolymer fire retardant of intermediate molecular weight of claim 1~6 Standby method, which is characterized in that the bromination process is：

In intermediate molecular weight brominated styrene/acrylate-diolefin-brominated styrene/acrylate triblock copolymer The isobutanol of addition copolymer 5~10 mass times, which is warming up to 30~70 DEG C, dissolves copolymer, and copolymer 1 is added under heat-retaining condition The bromating agent of~15 mass times is stirred to react 1~15h, with methanol extraction and filters after reaction, is dried under vacuum to constant weight, obtains To the brominated segmented copolymer fire retardant of intermediate molecular weight.

8. two one-step preparation method of lotion of the brominated segmented copolymer fire retardant of intermediate molecular weight according to claim 7, It is characterized in that：The bromating agent is bromine chloride or tetraethylammonium bromide.

It is 9. special using the brominated segmented copolymer fire retardant of intermediate molecular weight that claim 1~8 either method is prepared Sign is：The degree of polymerization is between 80~582.

10. the brominated segmented copolymer fire retardant of intermediate molecular weight according to claim 9, it is characterised in that：Bromine content For 70.2~74.8wt%.