阅读说明：本技术 一种应用含有活性官能团的溴系阻燃剂的高效阻燃聚苯乙烯的制备方法 (Preparation method of high-efficiency flame-retardant polystyrene by applying bromine flame retardant containing active functional group ) 是由 李书召 陈志强 于 2021-11-12 设计创作，主要内容包括：本申请涉及阻燃聚苯乙烯领域,具体公开了一种应用含有活性官能团的溴系阻燃剂的高效阻燃聚苯乙烯的制备方法。本申请通过将含活性官能团的溴系阻燃剂预先溶解于苯乙烯单体的反应体系中,形成分子水平分散的均相溶液。并通过含有特定活性官能团的烯类单体引发封端反应,在含有活性官能团的溴系阻燃剂末端引入双键,以便其以共聚的方式键合到聚苯乙烯分子链上。然后在反应釜中进行前期预聚,得到预聚体；再通过反应釜或者反应挤出的方式进行后聚合反应,制得高效阻燃聚苯乙烯树脂专用料或者阻燃母粒。本申请制备的高效阻燃聚苯乙烯树脂具有阻燃效果优异的优点,同时制得产品的安全、环保性能较好。(The application relates to the field of flame-retardant polystyrene, and particularly discloses a preparation method of high-efficiency flame-retardant polystyrene by applying a bromine flame retardant containing an active functional group. The bromine flame retardant containing the active functional group is dissolved in a reaction system of styrene monomer in advance to form a homogeneous solution with dispersed molecules. And initiating a blocking reaction by an olefin monomer containing a specific active functional group, and introducing a double bond at the tail end of the bromine flame retardant containing the active functional group so as to bond the bromine flame retardant to a polystyrene molecular chain in a copolymerization mode. Then, pre-polymerizing in the reaction kettle in the early stage to obtain a prepolymer; and carrying out post-polymerization reaction in a reaction kettle or a reaction extrusion mode to prepare the high-efficiency flame-retardant polystyrene resin special material or flame-retardant master batch. The high-efficiency flame-retardant polystyrene resin prepared by the method has the advantage of excellent flame-retardant effect, and the prepared product is safe and good in environmental protection performance.)

1. A preparation method of high-efficiency flame-retardant polystyrene by applying a bromine flame retardant containing active functional groups is characterized in that: the method comprises the following steps:

end capping of S1: mixing styrene monomer, brominated flame retardant containing active functional groups and alkene monomer containing specific active functional groups, heating to 90-140 ℃ after the brominated flame retardant containing active functional groups is completely dissolved, continuously stirring and carrying out end-capping reaction to obtain a mixture of brominated flame retardant containing double bonds introduced at the tail end;

s2 prepolymerization: adding an initiator into the mixture obtained in the end-capping step of S1, and performing prepolymerization to obtain a prepolymer;

s3 postpolymerization: and (4) continuously copolymerizing the prepolymer to obtain the high-efficiency flame-retardant polystyrene resin.

2. The preparation method of the high-efficiency flame-retardant polystyrene using the bromine-based flame retardant containing the active functional group according to claim 1, wherein the preparation method comprises the following steps: the brominated flame retardant containing the active functional group and the vinyl monomer containing the specific active functional group comprise at least one of tetrabromobisphenol A bis (hydroxyethyl) ether and maleic anhydride, 2,4,6 tribromoaniline and maleic anhydride, 2,4, 6-tribromobenzoic acid and glycidyl methacrylate, tetrabromophthalic anhydride and methacrylic acid.

3. The preparation method of the high-efficiency flame-retardant polystyrene using the bromine-based flame retardant containing the active functional group according to claim 1, wherein the preparation method comprises the following steps: the mass ratio of the bromine-based flame retardant containing the active functional group to the vinyl monomer containing the specific active functional group is (2-4): 1.

4. The preparation method of the high-efficiency flame-retardant polystyrene using the bromine-based flame retardant containing the active functional group according to claim 1, wherein the preparation method comprises the following steps: in the end capping step of S1, the end capping reaction time is 0.5 h-1.5 h.

5. The preparation method of the high-efficiency flame-retardant polystyrene using the bromine-based flame retardant containing the active functional group according to claim 1, wherein the preparation method comprises the following steps: the initiator is a composite initiator consisting of a low-temperature initiator and a medium-high temperature initiator according to the mass ratio of 3 (5-8).

6. The preparation method of the high-efficiency flame-retardant polystyrene using the bromine-based flame retardant containing the active functional group according to claim 1, wherein the preparation method comprises the following steps: in the step of terminating the end by S1, adding a flame-retardant synergist when mixing a styrene monomer, a brominated flame retardant and an alkene monomer containing a specific active functional group, wherein the flame-retardant synergist is antimony trioxide.

7. The preparation method of the high-efficiency flame-retardant polystyrene using the bromine-based flame retardant containing the active functional group according to claim 6, wherein the preparation method comprises the following steps: according to the total mass percentage of the styrene monomer, the brominated flame retardant containing the active functional group, the alkene monomer containing the specific active functional group and the flame retardant synergist, the mass percentage of the brominated flame retardant is 0.1-40%.

8. A fire retardant polystyrene plastic as claimed in any one of claims 1 to 7 wherein: prepared from high-efficiency flame-retardant polystyrene resin with 0.1 to 6 percent of brominated flame retardant; or the high-efficiency flame-retardant polystyrene resin with 6-40% of brominated flame retardant is used as master batch and added into general-purpose polystyrene to prepare the flame-retardant polystyrene resin, or the high-efficiency flame-retardant polystyrene resin with 6-40% of brominated flame retardant is used as master batch and added into impact-resistant polystyrene to prepare the flame-retardant polystyrene resin.

Technical Field

The application relates to the field of flame-retardant polystyrene, in particular to a preparation method of high-efficiency flame-retardant polystyrene by applying a bromine flame retardant containing active functional groups.

Background

Polystyrene is a polymer obtained by the polymerization of the monomer styrene. Polystyrene is widely used in various fields because of its excellent corrosion resistance, coloring effect and electrical properties.

However, polystyrene is extremely easy to burn, and not only a large amount of smoke is generated in the burning process, but also the phenomenon of melting and dropping occurs, so that the potential safety hazard is large. Therefore, the flame-retardant modification of the polystyrene is beneficial to expanding the application field of the polystyrene material.

In the related technology, the flame-retardant polystyrene is mainly prepared by melting and mixing various brominated flame retardants and other additives with polystyrene. However, the compatibility of the brominated flame retardant and polystyrene is poor, so that the dispersion effect of the brominated flame retardant in a polystyrene matrix is poor, and the flame retardant effect of the prepared polystyrene resin is poor.

Disclosure of Invention

In order to improve the flame retardant effect of the flame retardant polystyrene, the application provides a preparation method of the high-efficiency flame retardant polystyrene by applying a bromine flame retardant containing an active functional group.

In a first aspect, the application provides a preparation method of efficient flame-retardant polystyrene using a brominated flame retardant containing an active functional group, which adopts the following technical scheme:

a preparation method of high-efficiency flame-retardant polystyrene by using a bromine flame retardant containing active functional groups comprises the following steps:

end capping of S1: mixing styrene monomer, brominated flame retardant containing active functional groups and alkene monomer containing specific active functional groups, heating to 90-140 ℃ after the brominated flame retardant containing active functional groups is completely dissolved, continuously stirring and carrying out end-capping reaction to obtain a mixture of brominated flame retardant containing double bonds introduced at the tail end;

s2 prepolymerization: adding an initiator into the mixture obtained in the end-capping step of S1, and performing prepolymerization to obtain a prepolymer;

s3 postpolymerization: and (4) continuously copolymerizing the prepolymer to obtain the high-efficiency flame-retardant polystyrene resin.

By adopting the technical scheme, the bromine flame retardant containing the active functional group has a good flame retardant effect, can be uniformly dispersed in a styrene monomer after being stirred and mixed, and can be subjected to end-capping reaction with an alkene monomer containing a specific active functional group to obtain the bromine flame retardant with a double bond introduced at the tail end. In the styrene bulk copolymerization process, the brominated flame retardant with double bonds introduced at the tail end is bonded to a polystyrene molecular chain in a styrene copolymerization mode, so that the brominated flame retardant is further uniformly dispersed in a system, and the flame retardant effect of the prepared high-efficiency flame-retardant polystyrene resin is improved. Meanwhile, the brominated flame retardant is bonded to a polystyrene molecular chain in a manner of copolymerization with styrene, so that the precipitation of toxic bromine-containing compounds can be effectively reduced, and the prepared high-efficiency flame-retardant polystyrene resin has better safety and environmental protection performance.

In addition, the end capping reaction is carried out at the temperature of 90-140 ℃, which is beneficial to improving the effect of introducing double bonds in the end capping reaction, and further ensures that the flame retardant effect of the prepared high-efficiency flame-retardant polystyrene resin is better.

Preferably, the brominated flame retardant having a reactive functional group and the ethylenic monomer having a specific reactive functional group include at least one of tetrabromobisphenol a bis (hydroxyethyl) ether and maleic anhydride, 2,4,6 tribromoaniline and maleic anhydride, 2,4, 6-tribromobenzoic acid and glycidyl methacrylate, tetrabromophthalic anhydride and methacrylic acid.

By adopting the technical scheme, the bromine flame retardant containing the active functional group has better flame retardant effect in the four groups of corresponding bromine flame retardants containing the active functional group and alkene monomers containing the specific active functional group. The end capping reaction effect of the brominated flame retardant containing the active functional group and the corresponding vinyl monomer containing the specific active functional group is better, namely the effect of introducing double bonds into the tail end of the brominated flame retardant containing the active functional group is better, so that the copolymerization effect of the brominated flame retardant containing the active functional group and the styrene monomer is better, namely the effect of bonding the brominated flame retardant containing the active functional group to a polystyrene molecular chain is better, and the flame retardant effect of the prepared high-efficiency flame-retardant polystyrene resin is better. And the separated toxic bromine-containing compounds are reduced, which is beneficial to improving the safety and environmental protection performance of the product.

Preferably, the mass ratio of the bromine-based flame retardant containing the active functional group to the vinyl monomer containing the specific active functional group is (2-4): 1.

By adopting the technical scheme, the mass ratio of the bromine flame retardant containing the active functional group to the alkene monomer containing the specific active functional group is controlled to be (2-4): 1, which is beneficial to improving the completion degree of the end capping reaction, namely the completion degree of introducing double bonds into the tail end of the bromine flame retardant containing the active functional group is better, so that the bromine flame retardant containing the active functional group is better bonded to a polystyrene molecular chain in a manner of copolymerizing with a styrene monomer, and the flame retardant effect of the high-efficiency flame-retardant polystyrene resin is improved. And the bonding degree of the bromine flame retardant containing the active functional group is better, so that the amount of free and dispersed toxic bromine-containing compounds in the system can be effectively reduced, and the safety and environmental protection performance of the product are better.

Preferably, in the step of capping with S1, the capping reaction time is 0.5h to 1.5 h.

By adopting the technical scheme, because the reaction time is too short, the end-capping reaction of introducing double bonds into the brominated flame retardant containing the active functional groups cannot be fully completed; when the reaction time exceeds 2 hours, the styrene monomer may be thermally polymerized. Therefore, the end-capping reaction time is controlled to be 0.5 h-1.5 h, so that the thermal polymerization of the styrene monomer is reduced while the end-capping reaction is ensured to be better.

Preferably, the initiator is a composite initiator consisting of a low-temperature initiator and a medium-high temperature initiator according to the mass ratio of 3 (5-8).

By adopting the technical scheme, the low-temperature initiator and the medium-temperature initiator are compounded and then used as the initiator for system prepolymerization, so that the polymerization effect of the system in the whole temperature rising process is good, the polymerization efficiency and the polymerization degree of the system are favorably improved, the dispersion uniformity of the brominated flame retardant in the system is favorably improved, and the flame retardant effect of the prepared high-efficiency flame-retardant polystyrene resin is better. And under the condition that the mass ratio of the low-temperature initiator to the medium-temperature initiator is 3 (5-8), the polymerization efficiency and polymerization degree of the system are better, namely the flame retardant effect of the prepared high-efficiency flame-retardant polystyrene resin is better.

Preferably, in the end-capping step of S1, a flame retardant synergist is added when mixing a styrene monomer, a brominated flame retardant, and an alkene monomer containing a specific active functional group, and the flame retardant synergist is antimony trioxide.

By adopting the technical scheme, the flame-retardant synergist is beneficial to improving the flame-retardant effect of the brominated flame retardant, and the antimony trioxide is preferably selected, so that the flame-retardant effect of the prepared polystyrene resin is beneficial to improving.

Preferably, the mass percent of the brominated flame retardant is 0.1-40% in terms of the total mass of the styrene monomer, the brominated flame retardant containing the active functional group, the alkene monomer containing the specific active functional group and the flame retardant synergist.

By adopting the technical scheme, the mass percent of the brominated flame retardant containing the active functional group in the system is controlled to be 0.1-40%, the brominated flame retardant within the mass percent range has good dispersion uniformity in the styrene monomer, and the prepared high-efficiency flame-retardant polystyrene resin has good flame-retardant effect.

In a second aspect, the present application provides a flame retardant polystyrene plastic, which adopts the following technical scheme:

the flame-retardant polystyrene plastic is prepared by adding high-efficiency flame-retardant polystyrene resin with 0.1-6% of brominated flame retardant into general-purpose polystyrene or adding high-efficiency flame-retardant polystyrene resin with 6-40% of brominated flame retardant into impact-resistant polystyrene as master batch.

By adopting the technical scheme, the high-efficiency flame-retardant polystyrene resin with the brominated flame retardant content of 0.1-6% has better flame-retardant effect, and the flame-retardant extruded polystyrene foam plastic or flame-retardant expanded polystyrene foam plastic plate product prepared by taking the high-efficiency flame-retardant polystyrene resin as a special material has better flame-retardant effect. In addition, the high-efficiency flame-retardant polystyrene resin with the brominated flame retardant content of 6-40% is used as master batch and added into general-purpose polystyrene or impact-resistant polystyrene to prepare a flame-retardant product, and the flame-retardant effect is excellent. Therefore, a proper application approach can be selected according to the content of the brominated flame retardant in the high-efficiency flame-retardant polystyrene resin, so that the flame-retardant effect of the prepared product is excellent.

In summary, the present application has the following beneficial effects:

1. the bromine flame retardant containing the active functional group is used as a flame retardant active substance, and the vinyl monomer containing the specific active functional group and the bromine flame retardant containing the active functional group are subjected to end-capping reaction, so that a double bond is introduced into the tail end of the bromine flame retardant containing the active functional group. The double-bond-introduced brominated flame retardant containing the active functional group is bonded to a polystyrene molecular chain in a way of copolymerization with a styrene monomer, namely, on the basis of uniform dispersion of the brominated flame retardant containing the active functional group, the dispersion uniformity is further improved, and the flame retardant effect of the product is improved; meanwhile, as the brominated flame retardant containing the active functional group is bonded with a polystyrene molecular chain, the amount of the precipitated toxic bromine-containing compound can be effectively reduced, and the prepared product is safe and has better environmental protection performance.

2. The end capping reaction time is preferably 0.5 h-1.5 h, and the end capping reaction of introducing double bonds into the brominated flame retardant containing the active functional groups cannot be fully completed due to too short reaction time; when the reaction time exceeds 2 hours, the styrene monomer may be thermally polymerized. Therefore, the end-capping reaction time is controlled to be 0.5 h-1.5 h, so that the thermal polymerization of the styrene monomer is reduced while the end-capping reaction is ensured to be better.

3. The preparation method can prepare the flame-retardant polystyrene with different brominated flame retardant contents containing active functional groups, and the low-content flame-retardant polystyrene can be used as a special material for preparing flame-retardant extruded polystyrene foam plastics or flame-retardant expanded polystyrene foam plastic plate products. The high-content flame-retardant polystyrene can be used as master batch and added into general-grade polystyrene or impact-resistant polystyrene to prepare a flame-retardant product. The application approach is wide, and the flame retardant effect of the produced product is good.

Detailed Description

The embodiment provides a preparation method of efficient flame-retardant polystyrene by applying a bromine flame retardant containing active functional groups, which comprises the following steps:

end capping of S1: stirring and mixing a styrene monomer, a brominated flame retardant containing an active functional group and an alkene monomer containing a specific active functional group, heating to 90-140 ℃ after the brominated flame retardant containing the active functional group is completely dissolved, continuously stirring and carrying out end-capping reaction to obtain a mixture of the brominated flame retardant containing a double bond introduced at the tail end;

s2 prepolymerization: adding an initiator into the mixture obtained in the end-capping step of S1, and performing prepolymerization to obtain a prepolymer;

s3 postpolymerization: and transferring the prepolymer to a post-polymerization instrument for continuous copolymerization, and further performing devolatilization and granulation after copolymerization to obtain the high-efficiency flame-retardant polystyrene resin.

As for the initiator mentioned in the preparation method of the high-efficiency flame-retardant polystyrene of the present embodiment, a composite initiator composed of a peroxide initiator and an azo initiator is preferably used; wherein the peroxide initiator includes but is not limited to one or more of hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide tert-butyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, tert-butyl hydroperoxide, tert-butyl peroxybenzoate and 1, 4-bis (tert-butylperoxyisopropyl) benzene; azo initiators include, but are not limited to, at least one of azobisisobutyronitrile, dimethyl azobisisobutyrate, and azobisisoheptonitrile.

Bromine-based flame retardants containing reactive functional groups mentioned in the method for preparing high-efficiency flame-retardant polystyrene according to the present embodiment include, but are not limited to, tetrabromobisphenol a, 2,4,6 tribromophenol, dibromophenyl glycidyl ether, tetrabromobisphenol a bis (hydroxyethyl) ether, tetrabromophthalic acid diethylene glycol propylene glycol diester/diol, monobromopentyl glycol, dibromoneopentyl glycol, tribromoneopentyl glycol, dibromoneopentyl glycol, 2,4,6 tribromoaniline, 3, 4-dibromoaniline, 3-bromoaniline, 4-bromoaniline, 2, 5-dibromoaniline, 2, 6-dibromoaniline, 2, 4-dibromoaniline, 3, 5-dibromoaniline, 2-amino-5-bromobenzophenone, 3, 5-dibromo-4-methylaniline, N, N-bis (2-hydroxypropyl) -2,4, 6-tribromoaniline, 4-bromophthalic acid, tetrabromophthalic anhydride, 4-bromophthalic acid, 4-bromo-2, 6-diethylaniline, 4-chloro-2, 6-dibromoaniline, 4-bromo-2-methylaniline, 4-bromo-3-toluidine, 4-bromo-2, 6-dimethylaniline, 3-bromobenzyamine, 2-bromobenzyamine, 4-bromobenzyamine, 2- (4-bromophenyl) ethylamine, 2- (3-bromophenyl) ethylamine, 2- (2-bromophenyl) ethylamine, 1- (4-bromophenyl) ethylamine, bromine-substituted amino acids, amino acids, At least one of 2, 6-dibromo-4-isopropylaniline, 2,4, 6-tribromobenzoic acid and 3-hydroxy-2, 4, 6-tribromobenzoic acid.

The vinyl monomers having specific reactive functional groups mentioned in the method for preparing the high-efficiency flame-retardant polystyrene of the present embodiment include, but are not limited to, acrylic acid, methacrylic acid, diacrylic acid, dimethylacrylic acid, vinylphosphite, 2-vinyl-4, 6-diamino-1, 3, 5-triazine, 1, 2-epoxy-4-vinylcyclohexane, tetrahydroxybutyl vinyl ether, vinylsulfonic acid, epoxybutene, maleic anhydride, 2-vinyloxyethanol, epoxypropyl acrylate, at least one of diethylene glycol monovinyl ether, methacrylic acid, fumaric acid, itaconic acid, undecylenic acid, sorbic acid, glycidyl methacrylate, acrylamide, methacrylamide, N-methylolacrylamide, hydroxyethyl acrylate and hydroxypropyl acrylate.

The reaction time of the end capping reaction is preferably controlled to be 0.5 h-1.5 h, and if the reaction time is too short, the end capping reaction of the brominated flame retardant for introducing double bonds can not be fully completed; if the reaction time exceeds 2 hours, there is a possibility that the styrene monomer is thermally polymerized.

The reaction time for the prepolymerization is controlled to be 15 minutes to 2 hours, and preferably, the prepolymerization time is 30 minutes to 1 hour. The prepolymerization time is too short, so that the prepolymerization degree is insufficient, and the prepolymerization time is more than 2 hours, so that the reaction system is easy to be subjected to sudden polymerization, and the reaction is out of control.

The post-polymerization reaction in the present embodiment may be carried out in a reaction vessel, or may be carried out by a reactive extrusion polymerization in an extruder.

The extruder used for the post-polymerization extrusion may be a conventional twin-screw extruder, a single-screw extruder, a twin-stage extruder in which a single screw and a single screw are connected in series, a twin-stage extruder in which a twin screw and a twin-screw are connected in series, a twin-stage type extruder in which a single screw and a twin-screw are connected in series, or a twin-stage extruder in which a twin screw and a single screw are connected in series. The diameter (Φ D) of the extruder screw is not particularly limited and may be determined according to the amount of the throughput and the amount of the torque.

For the extruder used for reactive extrusion for post-polymerization, the residence time of the reaction system in the whole production line is preferably 20 to 90 minutes, and preferably 30 to 60 minutes. Too short a residence time of the material in the extruder reduces the conversion of the monomers; theoretically, the longer the residence time, the higher the conversion of the polymerization reaction, but too long a residence time leads to an excessive investment in equipment and a decrease in productivity.

The reaction temperature in the extruder mentioned in the present embodiment is set in the range of 20 to 250 ℃, preferably 30 to 200 ℃, and more preferably 70 to 180 ℃. The rotation speed of the extruder is set to be 1rpm to 1000rpm, preferably 10rpm to 500rpm, and more preferably 20rpm to 300rpm, and the yield is reduced by excessively low rotation speed; too high a rotational speed would result in too short a residence time of the material in the extruder to complete the reaction.

The present embodiment will be described in further detail with reference to examples.

The starting materials in the examples of the present application are all commercially available.

The general purpose polystyrene resin is produced by Suzhou Xinlii plastification Co., Ltd, and the product number is GPS-525N.

Examples

Examples 1 to 4 are different in that the selected bromine-based flame retardant having a reactive functional group and the vinyl monomer having a specific reactive functional group are different.

The following description will be given by taking example 1 as an example.

A preparation method of high-efficiency flame-retardant polystyrene by using a bromine flame retardant containing active functional groups comprises the following steps:

end capping of S1: under the protection of inert gas, adding 9750g of styrene monomer, 150g of brominated flame retardant containing active functional groups, 50g of flame retardant synergist and 50g of vinyl monomer containing specific active functional groups into a prepolymerization reaction kettle, and stirring and mixing until the brominated flame retardant containing active functional groups is completely dissolved; then heating to 125 ℃, continuing stirring, and carrying out end-capping reaction for 1h to obtain a mixture containing a brominated flame retardant with double bonds introduced at the tail end;

s2 prepolymerization: and after the end-capping reaction is finished, adding 50g of initiator into the prepolymerization reaction kettle, heating to 150 ℃ while stirring, carrying out prepolymerization reaction on the reaction system, and stopping heating after the reaction is carried out for 1 hour to obtain the prepolymer.

S3 postpolymerization: preheating a post-polymerization reaction kettle with a reflux condenser at the top to 170 ℃, then sending the prepolymer obtained in the step of pre-polymerizing S2 into the reaction kettle through a material delivery pump, and continuing to carry out polymerization reaction under the stirring state. After 8 hours of reaction, the temperature is raised to 230 ℃, then the materials are conveyed into a devolatilization kettle with the temperature preset to 230 ℃ and the pressure maintained at 3kPa, and unreacted styrene monomers are removed by flash evaporation. And finally, conveying the prepared copolymer to an outward rotating counter-rotating double-screw extruder, and further performing devolatilization and granulation to obtain the high-efficiency flame-retardant polystyrene resin.

Wherein the bromine flame retardant containing active functional groups is tetrabromobisphenol A bis (hydroxyethyl) ether;

the vinyl monomer containing the specific active functional group is maleic anhydride;

the flame-retardant synergist is antimony trioxide;

the initiator is a composite initiator consisting of a low-temperature initiator and a medium-high temperature initiator according to the mass ratio of 3:7, the low-temperature initiator is azobisisobutyronitrile, and the medium-high temperature initiator is 1, 4-bis (tert-butyl peroxyisopropyl) benzene.

Table 1 table for different material types in examples 1 to 4

Examples 5 to 8 are different from example 1 in that the post-polymerization step of S3 is carried out by using an extruder, and examples 5 to 8 are different in the selection of the bromine-based flame retardant having a reactive functional group and the vinyl monomer having a specific reactive functional group.

Example 5

In this example, the capping step of S1 and the prepolymerization step of S2 were the same as in examples 1 to 4. For the distinction S3 post polymerization step, it is specifically: and (3) conveying the prepolymer prepared in the step of pre-polymerizing S2 to an extruder, setting the temperature at 180 ℃, and setting the retention time of the prepolymer in the extruder to be 50 min. After the reaction is finished, devolatilizing through a vacuum system arranged at the tail end to obtain the high-efficiency flame-retardant polystyrene resin;

the extruder used therein was an extruder set of two screws with a diameter of 48, a length to diameter ratio of 65, connected in series.

Table 2 table for different material types in examples 5 to 8

Examples 9 to 12 were prepared by selecting different kinds of brominated flame retardants having active functional groups and vinyl monomers having specific active functional groups to prepare flame retardant polystyrene master batches having a high content of brominated flame retardants, and then blending the master batches with polystyrene resin to prepare flame retardant polystyrene resin having a low content of brominated flame retardants.

Example 9

In the embodiment, the mass of each material is 5000g of styrene monomer, 3000g of brominated flame retardant containing active functional groups, 1000g of alkene monomer containing specific active functional groups, 1000g of flame retardant synergist and 30g of initiator. The types of the materials are the same as that in the example 1, and the S1 end-capping step, the S2 prepolymerization step and the S3 post-polymerization step which are the same as those in the example 1 are adopted to prepare the flame-retardant polystyrene resin master batch with the high content of the brominated flame retardant.

The method for preparing the flame-retardant polystyrene resin with low content of the brominated flame retardant comprises the following steps: 500g of the flame-retardant polystyrene master batch with high content of the brominated flame retardant prepared in the embodiment, 9500g of general polystyrene resin and 50g of antioxidant 1010 are premixed in a high-speed mixer, and then added into a double-screw extruder with the diameter of 48mm and the length-diameter ratio of 35 to be extruded and granulated at 180 ℃ to prepare the flame-retardant polystyrene resin with low content of the brominated flame retardant.

Table 3 table for different material types in examples 9 to 12

Example 13

The difference between the present example and example 1 is that the mass of each material is 9725g of styrene monomer, 150g of bromine flame retardant containing active functional groups, 50g of flame retardant synergist, 75g of vinyl monomer containing specific active functional groups, and 50g of initiator. The preparation method of the high-efficiency flame-retardant polystyrene resin of this example is the same as that of example 1.

Example 14

The difference between the present example and example 1 is that the mass of each material is 9762.5g of styrene monomer, 150g of bromine flame retardant containing active functional groups, 50g of flame retardant synergist, 37.5g of vinyl monomer containing specific active functional groups and 50g of initiator. The preparation method of the high-efficiency flame-retardant polystyrene resin of this example is the same as that of example 1.

Example 15

This example differs from example 1 in that the capping reaction time was 0.5 h.

Example 16

This example differs from example 1 in that the capping reaction time was 1.5 h.

Example 17

The difference between the present embodiment and embodiment 1 is that the initiator is a composite initiator composed of a low-temperature initiator and a medium-high temperature initiator according to a mass ratio of 3:5, the low-temperature initiator is azobisisobutyronitrile, and the medium-high temperature initiator is 1, 4-bis (t-butylperoxyisopropyl) benzene.

Example 18

The difference between the present embodiment and embodiment 1 is that the initiator is a composite initiator composed of a low-temperature initiator and a medium-high temperature initiator according to a mass ratio of 3:8, the low-temperature initiator is azobisisobutyronitrile, and the medium-high temperature initiator is 1, 4-bis (t-butylperoxyisopropyl) benzene.

Example 19

This example differs from example 1 in that no flame retardant synergist was added.

Comparative example

Comparative example 1 the brominated flame retardant containing active functional groups and the vinyl monomer containing specific active functional groups selected in example 1 were directly melt-blended with general purpose polystyrene in an extruder and pelletized to prepare a flame retardant polystyrene resin.

Comparative example 1

The method for preparing the flame-retardant polystyrene resin in the comparative example specifically comprises the following steps: premixing 150g of brominated flame retardant containing an active functional group, 50g of vinyl monomer containing a specific active functional group, 50g of flame retardant synergist, 9750g of general polystyrene and 50g of antioxidant 1010 in a high-speed mixer, adding the premixed flame retardant, 9750g of general polystyrene and 50g of antioxidant 1010 into a double-screw extruder with the diameter of 48mm and the length-diameter ratio of 35, and extruding and granulating at 180 ℃ to obtain flame retardant polystyrene resin; and the kind of the materials of this comparative example was the same as example 1.

Comparative example 2 the brominated flame retardant containing active functional groups and the vinyl monomer containing specific active functional groups selected in example 1 were first made into a high content master batch with general purpose polystyrene and then blended with general purpose polystyrene to make a flame retardant polystyrene resin with a low content of brominated flame retardant.

Comparative example 2

The method for preparing the flame-retardant polystyrene resin in the comparative example specifically comprises the following steps: premixing 5000g of general polystyrene powder, 3000g of brominated flame retardant containing an active functional group, 1000g of vinyl monomer containing a specific active functional group, 1000g of flame retardant synergist and 30g of antioxidant 1010 in a high-speed mixer, adding the premixed materials into a double-screw extruder with the diameter of 48mm and the length-diameter ratio of 35, and performing extrusion granulation at 180 ℃ to prepare the flame retardant polystyrene resin master batch with high content of the brominated flame retardant;

then, 500g of the flame-retardant polystyrene master batch with high content of the brominated flame retardant prepared in the comparative example, 9500g of general polystyrene resin and 50g of antioxidant 1010 are premixed in a high-speed mixer, and then added into a double-screw extruder with the diameter of 48mm and the length-diameter ratio of 35 to be extruded and granulated at 180 ℃ to prepare the flame-retardant polystyrene resin with low content of the brominated flame retardant; and the kind of the materials of this comparative example was the same as example 1.

Comparative example 3

This comparative example is different from example 1 in that an ethylenic monomer having a specific reactive functional group is not added, and the balance is a styrene monomer.

Comparative example 4

This comparative example differs from example 1 in that the capping reaction time was 2.5 h.

Comparative example 5

This comparative example differs from example 1 in that the capping reaction time was 0.2 h.

Performance test

Detection method/test method

Oxygen index: the samples prepared in examples 1 to 19 and comparative examples 1 to 5 were tested according to the oxygen index method test standard in GB/T2406-1993 test methods for testing Plastic Combustion Properties.

Fire protection rating UL94 test: the samples prepared in examples 1 to 19 and comparative examples 1 to 5 were tested with reference to the test method for fire rating in UL 94-2009.

And (3) detecting the tensile strength: the samples prepared in examples 1 to 19 and comparative examples 1 to 5 were examined with reference to the test method for molding and extruding plastics in section 2 of GB/T1040.2-2006 "determination of tensile Properties of plastics".

TABLE 4 flame retardant Property test data sheet of samples

It can be seen from the detection data of each sample in table 4, and by combining the detection data of examples 1 to 4 and comparative examples 1 to 2, after the bromine-based flame retardant containing an active functional group and the vinyl monomer containing a specific active functional group are subjected to an end capping reaction, the bromine-based flame retardant is bonded to a polystyrene molecular chain in a manner of copolymerizing with a styrene monomer, and the obtained flame-retardant polystyrene has a more excellent flame-retardant effect compared with the flame-retardant polystyrene obtained by directly co-melting and extruding the bromine-based flame retardant containing an active functional group and polystyrene. And the obtained flame-retardant polystyrene resin has high flame-retardant effect no matter the polystyrene resin with low content of the brominated flame retardant is directly prepared, or the flame-retardant polystyrene master batch with high content of the brominated flame retardant is firstly prepared and then diluted into the flame-retardant polystyrene resin with low content of the brominated flame retardant. Meanwhile, the tensile strength of each sample in examples 1 to 19 is good, so that the preparation method in the application has a small influence on the tensile strength of the prepared flame-retardant polystyrene resin.

The detection data of the examples 1 to 4 and the comparative example 3 show that the brominated flame retardant containing the active functional group after the end capping reaction has better dispersion uniformity than the brominated flame retardant containing the active functional group directly dispersed in the styrene monomer, and is beneficial to improving the flame retardant effect of the prepared flame retardant polystyrene.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.