A multi-component high-efficiency flame-retardant phosphonate polymer, a preparation method and application thereof

Abstract

The application discloses a multi-component high-efficiency flame-retardant phosphonate polymer and a preparation method and application thereof. The multi-component high-efficiency flame-retardant phosphonate polymer has a structural formula as shown in formula (I), wherein R1 is selected from one of a phenyl group, a methoxy group and an ethoxy group; R2 is selected from one of a phenyl group, a methoxy group and an ethoxy group; R1 and R2 are the same group or different groups; and n is within a range of 6-18. Through molecular modification and design, the obtained phosphonate polymer has higher compatibility and flame-retardant efficiency compared with previous flame-retardant phosphonate materials, and the addition of the flame-retardant polymer can significantly improve the flame-retardant performance and physical performance of a resin material. Formula (I)

Description

Technical Field

[0001] This invention relates to the field of flame retardant materials technology, and in particular to a multi-component high-efficiency flame retardant phosphonate polymer, its preparation method, and its application. Background Technology

[0002] With the development of polymer materials science, the demand for polymers with special functions is increasing. While traditional polymers such as polyolefins and polyesters have wide applications, they have limitations in flame retardancy, biocompatibility, metal adhesion, and ionic conductivity, making it difficult to meet the increasingly demanding requirements of cutting-edge technology fields. Against this backdrop, phosphonate polymers have attracted widespread attention due to their unique molecular structure. The introduction of phosphonate groups can significantly improve the flame retardancy efficiency of materials, promoting char formation and isolating oxygen during combustion, while also reducing the release of toxic fumes. Simultaneously, their strong metal coordination ability can improve the adhesion between coatings and metal substrates, and as Lewis base sites, they can dissociate lithium salts, endowing materials with excellent ionic conductivity, which also has wide applications in the semiconductor field. However, existing synthesis methods for phosphonate polymers still face problems such as difficult monomer purification, harsh polymerization conditions, and poor product stability, leading to unstable product performance and high costs, limiting their large-scale application. Therefore, developing a novel synthesis process with mild conditions and simple steps has become crucial for promoting the practical application of this type of high-performance polymer. Summary of the Invention

[0003] This invention aims to overcome the problems of harsh reaction conditions, difficult purification, and poor structural thermal stability in the prior art, and provides a multi-component high-efficiency flame-retardant phosphonate polymer, its preparation method and application. Through molecular modification and design, the obtained phosphonate polymer has a higher phosphine content, higher compatibility and flame-retardant efficiency compared with the previous phosphonate flame-retardant materials. The addition of this flame-retardant polymer can significantly improve the flame-retardant performance and physical properties of resin materials.

[0004] This invention is achieved through the following technical solutions:

[0005] This invention protects a multi-component, high-efficiency flame-retardant phosphonate polymer, the structural formula of which is shown in formula (I):

[0006]

[0007] Formula (I)

[0008] Wherein: R1 is selected from one of phenyl, methoxy, and ethoxy; R2 is selected from one of phenyl, methoxy, and ethoxy.

[0009] R1 and R2 can be the same or different groups, and the value of n ranges from 6 to 18.

[0010] Preferably, when R1 or R2 is methoxy or ethoxy, in formula (I), the lower alcohols will be removed to form interchain phosphonate bonds.

[0011] Preferably, the value of n is in the range of 8-13.

[0012] This invention also protects a method for preparing the aforementioned multi-component high-efficiency flame-retardant phosphonate polymer, comprising the following steps:

[0013] S1. Add the phosphonite ester and solvent to the reaction vessel, and add the catalyst, ligand and m-tribromobenzene under nitrogen protection. After heating to 65℃-75℃ and reacting for 2-6 h, an intermediate system is obtained. The phosphonite ester is selected from one of diphenylphosphonite monoethyl ester, diphenylphosphonite monomethyl ester, diethyl phenylphosphonite, dimethyl phenylphosphonite, and triethyl phosphonite. The catalyst is selected from one of palladium acetate, bis(triphenylphosphine)dichloride, and palladium trifluoroacetate. The ligand is selected from one of triphenylphosphine, tri-tert-butylphosphine, and 1,1'-bis(diphenylphosphine)ferrocene.

[0014] S2. Add diethyl phenylphosphonite, triethyl phosphonite, and tris(dibenzylacetone)dipalladium to the intermediate system obtained in step S1. Under nitrogen protection, heat the mixture to 125℃-135℃ and react for 14-18 h. After confirming that there is no residual substrate, evaporate the solvent.

[0015] S3. Add an ethanol-xylene mixed solution to the system obtained in step S2, heat to 75℃-85℃ and reflux for 1.5-2.5 h, repeat the slurrying several times, filter out the solid, and dry to obtain the product, namely the multi-component high-efficiency flame-retardant phosphonate polymer.

[0016] This invention utilizes the Michaelis-Arbuzov reaction to generate phosphonate polymers from phosphonites. By selecting the organic monomers and employing a controlled polymerization process in a multi-component reaction system, the polymer chains can form network structures with varying degrees of cross-linking as needed, significantly improving the stability and flame retardant properties of the product. This preparation method uses m-tribromobenzene and phosphonites as the main raw materials. By controlling the substrate feed method and reaction conditions, the polymerization reaction is carried out under relatively mild conditions (80°C-160°C). The obtained product has a high phosphine content, which significantly improves the flame retardant properties of the resin material.

[0017] Preferably, the solvent in step S1 is selected from xylene and N,N-dimethylformamide, the molar ratio of the solvent to m-tribromobenzene is 2.5:1, the molar ratio of the catalyst to m-tribromobenzene is 0.002:1, the molar ratio of the ligand to m-tribromobenzene is 0.004:1, and the molar ratio of the phosphonite to m-tribromobenzene is 1:1.

[0018] Preferably, in step S2, the molar ratio of diethyl phenylphosphonite, triethyl phosphonite, and m-tribromobenzene is 1:1:1, and the molar ratio of tris(dibenzylacetone)dipalladium to m-tribromobenzene is 0.003:1.

[0019] Preferably, the ethanol-xylene mixed solution in step S3 is an 80% ethanol-20% xylene mixed solution, the volume of which is 1 times the volume of the solvent in step S1, and the drying temperature is 85°C.

[0020] This invention also protects the use of the aforementioned multi-component high-efficiency flame-retardant phosphonate polymer as a flame-retardant additive in the preparation of flame retardants.

[0021] Preferably, the flame retardant is flame-retardant PC resin.

[0022] The present invention also protects a flame retardant comprising, by weight, the following components: 80-95 parts of PC resin, 5-20 parts of the multi-component high-efficiency flame-retardant phosphonate polymer, and 0.1 parts of additives.

[0023] Preferably, the flame retardant comprises, by weight, the following components: 85 parts PC resin, 15 parts multi-component high-efficiency flame-retardant phosphonate polymer, and 0.1 parts additives.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. The flame-retardant polymer proposed in this invention is added to PC resin in the form of a flame-retardant additive. It can maintain a low exudation rate and migration rate under long-term high temperature and high humidity environment, and maintain excellent physical properties and flame-retardant properties, which are significantly better than traditional additive flame retardants. At the same time, since the molecular structure of the product can be adjusted according to the application requirements to adapt to different performance requirements, it has a wide range of application prospects.

[0026] 2. Through molecular modification and design, this invention enables the obtained flame-retardant polymer molecules to have better compatibility with PC resin; and by adjusting the type of substrate during the reaction process, the degree of crosslinking of the product can be more precisely adjusted, so that the physical properties of the specimens made using this flame retardant can be adapted to different product requirements, and have a wider range of application prospects. Attached Figure Description

[0027] Figure 1 The product of Example 1 1 H-NMR spectrum.

[0028] Figure 2 The product of Example 1 13 C-NMR spectrum.

[0029] Figure 3The product of Example 2 1 H-NMR spectrum.

[0030] Figure 4 The product of Example 2 13 C-NMR spectrum.

[0031] Figure 5 The product of Example 3 1 H-NMR spectrum.

[0032] Figure 6 The product of Example 3 13 C-NMR spectrum. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are considered to be commercially available materials and reagents that can be obtained through conventional markets and other commercial channels.

[0034] In the following examples, the number of parts refers to the amount of substance.

[0035] Example 1

[0036] A method for preparing a multi-component, high-efficiency flame-retardant phosphonate polymer includes the following steps:

[0037]

[0038] S1. Add 30 parts of monoethyl diphenylphosphonite and 75 parts of xylene to a reaction flask. Under nitrogen protection, add 0.06 parts of palladium acetate, 0.12 parts of triphenylphosphine and 30 parts of m-tribromobenzene. Heat to 70℃ and react for 4 h. TLC and HPLC confirmed that the product is mainly monosubstituted, and the intermediate system is obtained.

[0039] S2. Add 30 parts of diethyl phenylphosphonite, 30 parts of triethyl phosphonite, and 0.09 parts of tris(dibenzylacetone)dipalladium to the intermediate system obtained in step S1. Under nitrogen protection, heat to 125°C and react for 16 h. After confirming by TLC and HPLC that there is no bromobenzene residue, evaporate the solvent under vacuum.

[0040] S3. Add the same volume of 80% ethanol-20% xylene mixed solution as xylene to the system obtained in step S2, heat to 80℃ and reflux for 2 hours, repeat the slurrying process twice, filter out the solid and dry at 85℃ to obtain the product.

[0041] GPC measurements showed a 90% molecular weight of 2560, which translates to an n value of approximately 8.

[0042] The product was analyzed by proton NMR spectroscopy, such as... Figure 1 As shown, multiple peak signal responses exist in the vicinity of δ ~7.5-8.5 ppm, which is a typical characteristic of hydrogen atoms in the benzene ring. The hydrogen atoms on the benzene ring mainly exhibit three sets of signals and multiple splitting, indicating the presence of two major classes of aromatic ring protons with similar chemical environments within the structure, and the coupling between adjacent protons and meta protons at a distance. Fitting the integral ratio, the degree of polymerization of the polymer is estimated to be approximately 8.3, which is consistent with the GPC test results.

[0043] In the δ ~ 4.5 ppm range, a multi-symmetric splitting response exists, corresponding to the methylene group (-O-CH2-CH3) in the ethyl group attached to the phosphine atom. Because this -CH2- is directly bonded to the strongly electron-withdrawing phosphine oxide (P=O) group, its electron cloud density decreases, causing the signal to shift towards a lower field. This signal exhibits multiple peaks, resulting from the coupling splitting of the hydrogen atom on the methylene group with the adjacent phosphorus atom (³¹P, spin quantum number I=1 / 2) and the hydrogen atom on the methyl group.

[0044] A triplet response exists in the δ ~ 1.3 ppm range, corresponding to the methyl group (-O-CH2-CH3) in ethyl groups. Its chemical shift of 1.3 ppm is typical for methyl groups in saturated alkanes. The splitting of this signal into a distinct triplet is due to the coupling effect of adjacent methylene groups.

[0045] Based on the integral ratio of the aromatic region and the corresponding end groups, the 1H NMR spectrum is basically consistent with the proposed chemical structure. However, since the actual degree of polymerization of the polymer may vary slightly, the calculated degree of polymerization often only represents the estimated value.

[0046] The product was subjected to carbon NMR spectroscopy, such as... Figure 2 As shown, in the δ ~125-130 ppm region, multiple carbon atom responses are observed. This region typically corresponds to aromatic carbons directly bonded to oxygen or phosphine (such as CO or CP bonds), ester carbons (C=O), or carbons conjugated with heteroatoms on the aromatic ring. The signals are dense and high in intensity, suggesting the presence of multiple similar environmental carbon atoms in the structure. In the δ ~131 ppm region, a single carbon atom response is observed, corresponding to an unsubstituted carbon (CH) on the aromatic ring or an olefin carbon (C=C).

[0047] At δ ~64ppm: there is a carbon atom response, usually corresponding to an aliphatic carbon bonded to oxygen (such as CO, for example -CH2- in ethoxy).

[0048] At δ ~16ppm: there is a single carbon atom response, corresponding to a terminal methyl structure or an aliphatic carbon far from the functional group.

[0049] Combination 1 H-NMR and 13 C-NMR testing showed that the structure was basically consistent with the prediction.

[0050] Example 2

[0051] A method for preparing a multi-component, high-efficiency flame-retardant phosphonate polymer includes the following steps:

[0052]

[0053] S1. Add 60 parts of diethyl phenylphosphonite and 150 parts of xylene to a reaction flask. Under nitrogen protection, add 0.12 parts of palladium acetate, 0.24 parts of tri-tert-butylphosphine and 60 parts of m-tribromobenzene. Heat to 70℃ and react for 3 h. TLC and HPLC confirmed that the product is mainly monosubstituted, and the intermediate system is obtained.

[0054] S2. Add 60 parts of diethyl phenylphosphonite, 60 parts of triethyl phosphonite, and 0.18 parts of tris(dibenzylacetone)dipalladium to the intermediate system obtained in step S1. Under nitrogen protection, heat to 130°C and react for 16 h. After confirming by TLC and HPLC that there is no bromobenzene residue, evaporate the solvent under vacuum.

[0055] S3. Add the same volume of 80% ethanol-20% xylene mixed solution as xylene to the system after solvent removal in step S2, heat to 80℃ and reflux for 2 h, repeat the slurrying process twice, filter out the solid and dry at 85℃ to obtain the product.

[0056] GPC measurements showed that 90% of the molecular weight was 4000, which translates to an n value of approximately 13.

[0057] The product was analyzed by proton nuclear magnetic resonance spectroscopy, such as... Figure 3 As shown, the multiple peak response in the low-field region (δ ~ 8 ppm) indicates the presence of a distinct benzene ring structure. Integrating and comparing this region, the calculated n-value is approximately 13.3, consistent with GPC results. A set of peaks in the δ ~ 4 ppm spectrum precisely corresponds to the methylene (-CH2-) bonded to oxygen in the ethoxy group (-OEt). Its splitting pattern is as expected. A set of the strongest, sharpest signals in the δ ~ 2 ppm spectrum corresponds to the methyl group (-CH3) at the ethoxy terminal. The sharp and symmetrical peak shape indicates a highly homogeneous chemical environment for this methyl group, representing a free terminal hydrogen. The product was analyzed by carbon NMR spectroscopy, as shown... Figure 4As shown, signal clusters exist in the δ ~100-160 ppm range, which is typical of carbon atoms on the benzene ring. Due to the highly symmetrical structure of this oligomer and the large number of repeating units (n=13), the chemical environments of the benzene ring carbons in all repeating units are almost identical, resulting in highly concentrated signals, which appear as dense signal clusters in the spectrum. A signal intensity response appears in the δ ~150 ppm range, consistent with the characteristic chemical shift of carbon atoms on the benzene ring directly bonded to phosphine (or to an oxygen ether bond). This corresponds to carbon atoms in the structure directly bonded to phosphine-oxygen bonds (PO-Ar) or ethoxy-oxygen bonds (O-CH2CH3) on the benzene ring. These carbons exhibit a deshielding effect due to their bond with highly electronegative atoms, resulting in a lower field signal. There is a very sharp and extremely strong single peak at δ ~65 ppm. This is the classic signal position of methylene carbons (-O-CH2-) directly bonded to oxygen atoms. Due to the presence of numerous ethoxymethylene groups with completely identical chemical environments in the structure, the signal response in this region is relatively strong. A sharp, high-intensity singlet peak is observed at δ ~16 ppm. This is the characteristic chemical shift of the ethoxy-terminal methyl carbon (-CH3). In the carbon region of δ ~0-50 ppm, in addition to the main methyl and methylene peaks, there are very trace amounts of chain-terminal groups or defective carbon signals due to limited polymerization degree (n=13). Because their content is extremely low, the signal intensity is very weak and does not affect the judgment of the main structure. The two spectra show that the sample is a target oligomer with high symmetry and regularity, and its structure is basically consistent with the structural diagram.

[0058] Example 3

[0059] A method for preparing a multi-component, high-efficiency flame-retardant phosphonate polymer includes the following steps:

[0060]

[0061] S1. Add 60 parts and 150 parts of N,N-dimethylformamide to a reaction flask, and under nitrogen protection, add 0.12 parts of palladium acetate, 0.24 parts of 1,1'-bis(diphenylphosphine)ferrocene and 60 parts of m-tribromobenzene. Heat to 70℃ and react for 4 h. TLC and HPLC confirmed that the product is mainly monosubstituted, and the intermediate system is obtained.

[0062] S2. Add 60 parts of diethyl phenylphosphonite, 60 parts of triethyl phosphonite, and 0.18 parts of tris(dibenzylacetone)dipalladium to the intermediate system obtained in step S1. Under nitrogen protection, heat to 135℃ and react for 16 h. After confirming by TLC and HPLC that there is no bromobenzene residue, evaporate N,N-dimethylformamide under reduced pressure.

[0063] S3. Add the same volume of 80% ethanol-20% xylene mixed solution as N,N-dimethylformamide to the system after solvent removal in step S2, heat to 80℃ and reflux for 2 h, repeat the slurrying process twice, filter out the solid and dry at 85℃ to obtain the product.

[0064] GPC analysis revealed a 90% molecular weight of 3100, which translates to an n value of approximately 10. The product was then monitored using 1H NMR spectroscopy. Figure 5 As shown, multiple peak responses are observed in the δ ~ 8 ppm range. Due to the connection between the benzene ring and the strong electron-withdrawing group (P=O), the electron cloud density of the aromatic hydrogens decreases, causing the chemical shift to move to a lower field. The signal in this region of the spectrum is more numerous and partially overlapped, which is consistent with the fact that each repeating unit in the structural formula contains multiple aromatic hydrogens with similar chemical environments. The integral comparison of the number of hydrogen atoms in the benzene ring in this region yields n to be approximately 10, which is consistent with the GPC test results.

[0065] A proton response exists at δ ~4ppm, and the narrow peak shape indicates that the proton at this location is less affected by long-range coupling, showing that it is an isolated proton, which is consistent with the methylene proton signal characteristics of the ethoxy group in the structural formula.

[0066] A sharp singlet signal exists at δ~2 ppm, which strongly suggests the presence of a methyl (-CH3) proton, and that the methyl group is attached to a saturated carbon atom. This corresponds to the methyl signal in the end-capping group of the structure, but its chemical shift is usually between 1.0 and 1.5 ppm.

[0067] The product was analyzed by carbon nuclear magnetic resonance spectroscopy, such as... Figure 6 As shown. In the δ~150-160 ppm region: it should be attributed to aromatic ring carbon atoms (C—O) directly bonded to oxygen atoms, and aromatic ring carbon atoms that may be bonded to phosphorus atoms.

[0068] In the δ~110-140 ppm region: corresponding to the unsubstituted aromatic carbons (C—H) on the benzene ring.

[0069] In the δ~60-70 ppm region: it matches the signal of methylene carbon (—O—CH2—) in ethoxy.

[0070] In the δ~15-20 ppm region: this should correspond to the methyl carbon (—CH3) in the ethoxy group. The presence of this signal corroborates the methyl proton signal near 2 ppm in ¹H NMR, further supporting the presence of a methyl group in the structure or at the terminal group.

[0071] The number of asymmetric carbon environments in the spectral structure is basically matched. Due to the high symmetry of the molecule, many carbon atoms in each repeating unit are equivalent, so the number of spectral lines actually observed may be less than the total number of carbon atoms in the structure.

[0072] according to1 H-NMR and 13 The C-NMR spectrum yielded a structure that was largely consistent with the predicted structure in the formula.

[0073] Application Example 1

[0074] Weigh out 1700 g of PC (PC-110, Chimei), 300 g of flame retardant additive (the high-efficiency flame retardant polymer synthesized in Example 1), and 2 g of PTFE powder, and mix them evenly using a high-speed mixer; extrude and granulate using a twin-screw extruder at an extrusion temperature of 170℃-190℃; prepare flame retardant PC specimens using an injection molding machine. The flame retardant specimens are 125 mm long, 13.0 mm wide, and 1.6 mm thick; notched impact specimens are 100 mm long, 8.0 mm wide, and 4.0 mm thick. The specific proportions are shown in Table 1.

[0075] Application Example 2

[0076] The preparation method for this application example is the same as that for Application Example 1, except that the flame retardant additive used is the flame retardant polymer prepared in Example 2. Specific proportions are shown in Table 1.

[0077] Application Example 3

[0078] The preparation method for this application example is the same as that for Application Example 1, except that the flame retardant additive used is the flame retardant polymer prepared in Example 3. Specific proportions are shown in Table 1.

[0079] Comparative Example 1

[0080] The preparation method for this comparative example is the same as that for application example 1, except that the flame retardant additive used is BDP (WSFR-BDP, Wansheng). The specific proportions are shown in Table 1.

[0081] Comparative Example 2

[0082] The preparation method for this comparative example is the same as that for application example 1, except that the flame retardant additive used is RDP (WSFR-RDP, Wansheng). The specific proportions are shown in Table 1.

[0083] Comparative Example 3

[0084] The preparation method for this comparative example is the same as that for application example 1, except that the flame retardant additive used is 240 g of decabromodiphenyl ethane and 60 g of antimony trioxide. The specific ratio is shown in Table 1.

[0085] Table 1

[0086]

[0087] The tests were conducted according to the UL-94 vertical burning test standard and the cantilever beam notched impact test standard, and the results are shown in Table 2.

[0088] Table 2

[0089]

[0090] Table 2 shows that the flame-retardant PC resins prepared in Application Examples 1-3 all achieved a flame retardant rating of V0, which is superior to the V1 rating of Comparative Examples 1-2 and comparable to the flame retardant effect of the bromine-antimony flame retardant in Comparative Example 3. The impact strength of the flame-retardant PC materials prepared in Application Examples 1-3 was also significantly better than that of Comparative Examples 1-2, and the impact resistance improved with the increase in the degree of crosslinking of phosphonate esters in the polymer chain. In summary, the flame-retardant properties of the phosphonate ester polymers proposed in this invention are superior to commonly used phosphonate esters BDP and RDP, comparable to the flame retardant effect of bromine-antimony flame retardants, and superior to traditional phosphonate ester and bromine-antimony flame retardants in terms of impact resistance. Furthermore, with the change in raw materials, the increased degree of crosslinking between polymer chains in Application Examples 1-3 led to a certain improvement in the impact resistance of the specimens. However, the transparency decreased slightly, which is due to the different substrates of the polymer materials, resulting in differences in compatibility with the resin materials.

[0091] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A multi-component, high-efficiency flame-retardant phosphonate polymer, characterized in that, Its structural formula is shown in equation (I): Formula (I) Wherein: R1 is selected from one of phenyl, methoxy, and ethoxy; R2 is selected from one of phenyl, methoxy, and ethoxy; R1 and R2 are the same group or different groups, and the value of n ranges from 6 to 18.

2. The multi-component high-efficiency flame-retardant phosphonate polymer according to claim 1, characterized in that, When R1 or R2 is methoxy or ethoxy, in formula (I), the lower alcohol will be removed to form interchain phosphonate bonds.

3. The multi-component high-efficiency flame-retardant phosphonate polymer according to claim 1 or 2, characterized in that, The value of n ranges from 8 to 13.

4. The method for preparing the multi-component high-efficiency flame-retardant phosphonate polymer according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Add the phosphonite ester and solvent to the reaction vessel, and add the catalyst, ligand and m-tribromobenzene under nitrogen protection. After heating to 65℃-75℃ and reacting for 2-6 h, an intermediate system is obtained. The phosphonite ester is selected from one of diphenylphosphonite monoethyl ester, diphenylphosphonite monomethyl ester, diethyl phenylphosphonite, dimethyl phenylphosphonite, and triethyl phosphonite. The catalyst is selected from one of palladium acetate, bis(triphenylphosphine)dichloride, and palladium trifluoroacetate. The ligand is selected from one of triphenylphosphine, tri-tert-butylphosphine, and 1,1'-bis(diphenylphosphine)ferrocene. S2. Add diethyl phenylphosphonite, triethyl phosphonite, and tris(dibenzylacetone)dipalladium to the intermediate system obtained in step S1. After reacting at 125℃-135℃ for 14-18 h under nitrogen protection, remove the solvent after confirming that there is no residual substrate. S3. Add an ethanol-xylene mixed solution to the system obtained in step S2, heat to 75℃-85℃ and reflux for 1.5-2.5 h, repeat the slurrying several times, filter out the solid, and dry to obtain the product, namely the multi-component high-efficiency flame-retardant phosphonate polymer.

5. The preparation method according to claim 4, characterized in that, The solvent mentioned in step S1 is selected from xylene and N,N-dimethylformamide. The molar ratio of the solvent to m-tribromobenzene is 2.5:1, the molar ratio of the catalyst to m-tribromobenzene is 0.002:1, the molar ratio of the ligand to m-tribromobenzene is 0.004:1, and the molar ratio of the phosphonite to m-tribromobenzene is 1:

1.

6. The preparation method according to claim 4, characterized in that, In step S2, the molar ratio of diethyl phenylphosphonite, triethyl phosphonite, and m-tribromobenzene is 1:1:1, and the molar ratio of tris(dibenzylacetone)dipalladium to m-tribromobenzene is 0.003:

1.

7. The preparation method according to claim 4, characterized in that, The ethanol-xylene mixed solution mentioned in step S3 is an 80% ethanol-20% xylene mixed solution, the volume of which is 1 times the volume of the solvent mentioned in step S1, and the drying temperature is 85°C.

8. The use of the multi-component high-efficiency flame-retardant phosphonate polymer according to any one of claims 1-3 or the multi-component high-efficiency flame-retardant phosphonate polymer obtained by the preparation method according to any one of claims 4-7 as a flame-retardant additive in the preparation of flame retardants.

9. The application according to claim 8, characterized in that, The flame retardant is flame-retardant PC resin.

10. A flame retardant, characterized in that, The product comprises, by mass parts, the following components: 80-95 parts of PC resin, 5-20 parts of the multi-component high-efficiency flame-retardant phosphonate polymer as described in any one of claims 1-3 or the multi-component high-efficiency flame-retardant phosphonate polymer obtained by the preparation method described in any one of claims 4-7, and 0.1 parts of additives.

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