Diphosphine oxide compound, synthetic method thereof and application of diphosphine oxide compound in flame retardance and aging resistance of resin

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a diphosphine oxide compound, a photochemical synthesis method of the diphosphine oxide compound and application of the diphosphine oxide compound in flame retardance and aging resistance of resin. The diphosphine oxide compound can be used as a flame retardant, and the polyphosphine oxide compound prepared from the diphosphine oxide compound can be used as an anti-aging agent. The diphosphorus oxide compound disclosed by the invention can well realize flame retardance of various high polymer materials including polyurethane and epoxy resin. The poly (diphosphorus oxide) compound disclosed by the invention shows relatively good anti-aging performance in a polyurethane material.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a bisphosphine oxide compound, its photochemical synthesis method, and its application in resin flame retardancy and anti-aging. Background Technology

[0002] Bisphosphine oxides are an important class of organophosphorus compounds, whose molecular structure contains two phosphonoyl (P=O) functional groups linked by PP bonds. These compounds play a crucial role in coordination chemistry, materials science, and separation science due to their strong coordination ability, unique electronic properties, and spatial structure. Therefore, developing green and efficient methods for synthesizing bisphosphine oxide molecules is of great significance.

[0003] Traditional synthetic methods for bisphosphonates mainly rely on the condensation reactions of phosphate esters or phosphonyl chlorides, but these methods typically require stoichiometric activating agents and suffer from poor atom economy. As early as 1950, Steinberg, GM, et al. first reported the condensation of diethyl phosphate in the presence of carbon tetrachloride and triethylamine, yielding tetraethyl hypophosphite in only 17% yield, accompanied by a large amount of byproducts (Steinberg, GM, et al., J. Am. Chem. Soc. 1950, 15, 637–647). In 1965, Zwierzak, A., et al. increased the yield to 53% by reacting sodium diethyl phosphate with diethyl phosphonyl chloride, but the reaction still required the prior preparation of a phosphonyl chloride precursor (Zwierzak, A., et al., Sci. Ser. Sci. Chim. 1965, 13, 253–259). In 1966, Quin, LD, et al. improved this method, achieving the synthesis of tetraphenyldiphosphine oxide using dichloroarylphosphine in the presence of triethylamine, with a calculated yield of 72%. However, the method still faced limitations due to difficulties in product separation and purification (Quin, LD, et al., J. Org. Chem. 1966, 31, 1206–1209). Until 2010, Zhou, Y., et al. developed a copper-catalyzed dehydrogenation coupling strategy for phosphine hydrides, achieving the first highly selective synthesis of bisphosphine oxide molecules, providing a new approach for the green preparation of these compounds (Zhou, Y., et al., Angew. Chem. Int. Ed. 2010, 49, 6852–6855). Nevertheless, existing methods still have significant shortcomings in terms of catalytic system universality, substrate applicability, and functional group compatibility. Therefore, developing novel strategies for the synthesis of bisphosphine oxides that are mild, require no metal catalysts or stoichiometric oxidants, and have good functional group tolerance remains an important challenge in organophosphorus chemistry. Summary of the Invention

[0004] To address the above needs, this invention utilizes a green and mild organic photochemical technique to achieve the simple and efficient preparation of bisphosphine oxide molecules using structurally diverse phosphorus and hydride compounds. This method offers advantages such as readily available and simple reactants, environmentally friendly solvents, and easy separation procedures. The resulting structurally diverse compounds can be widely applied in various fields, including organic materials, pharmaceuticals, pesticides, and materials science.

[0005] Therefore, one objective of this invention is to provide structurally diverse bisphosphine oxide compounds. These compounds can be used as flame retardants for polymeric materials. Secondly, this invention provides a method for preparing these compounds, using phosphate compounds as raw materials and achieving the synthesis of the target compound in one step via visible light catalysis. This method is mild, uses readily available and simple raw materials, and requires no complicated operations, making it a convenient method suitable for large-scale preparation. Thirdly, the obtained compounds are used as monomers for polymerization, and the resulting polybisphosphine oxide compounds are applied to the anti-aging properties of materials.

[0006] Specifically, in one aspect, the present invention provides bisphosphine oxide compounds as shown in formula (II):

[0007]

[0008] Among them, R1, R2, R3, and R4 may be the same or different, and each is independently C. 1-4 Alkoxy, halogenated C 1-4 Alkoxy, -C 1-4 alkoxy-phenyl, biphenyl, or substituted or unsubstituted C 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkyl groups; or R1 and R2 combined with P attached to them to form phosphenanthrene groups; or R3 and R4 combined with P attached to them to form phosphenanthrene groups.

[0009] Furthermore, R1, R2, R3, and R4 may be the same or different, and each independently is methoxy, ethoxy, fluoromethoxy, fluoroethoxy, phenoxy, biphenyl, naphthyl, or a substituted or unsubstituted phenyl group; the substituent of the phenyl group is F, Cl, Br, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, or tert-butoxy; or R1 and R2 combined with the P group attached to them form a phosphenanthrene group; or R3 and R4 combined with the P group attached to them form a phosphenanthrene group.

[0010] Furthermore, R1, R2, R3, and R4 may be the same or different, and each independently represents methoxy, ethoxy, fluoromethoxy, fluoroethoxy, phenoxy, naphth-1-yl, naphth-2-yl, biphenyl, phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 3,5-dimethylphenyl, etc. tert-butylphenyl, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, o-ethoxyphenyl, m-ethoxyphenyl, p-ethoxyphenyl, o-fluorophenyl, m-fluorophenyl, p-fluorophenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, o-bromophenyl, m-bromophenyl, p-bromophenyl, o-nitrophenyl, m-nitrophenyl, p-nitrophenyl, o-cyanophenyl, m-cyanophenyl, p-cyanophenyl; or R1 and R2 combined with P attached to them to form phosphenanthrene; or R3 and R4 combined with P attached to them to form phosphenanthrene.

[0011] Furthermore, the bisphosphine oxide compound is selected from the following compounds 1-20:

[0012] .

[0013] In another aspect, the present invention provides a photochemical synthesis method for bisphosphine oxide compounds as shown in formula (II), comprising the following steps: reacting a phosphine compound as shown in formula (I) and a phosphine compound as shown in formula (I') with a photocatalyst in an organic solvent and under light irradiation (e.g., in an LED light source). The reaction formula is as follows:

[0014]

[0015] Furthermore, in the above method, the phosphorus compounds represented by formula (I) and formula (I') are each independently selected from diphenylphosphine oxide, bis(4-methoxyphenyl)phosphine oxide, bis(4-chlorophenyl)phosphine oxide, bis(4-bromophenyl)phosphine oxide, bis(3,5-di-tert-butylphenyl)phosphine oxide, bis(3,5-dimethylphenyl)phosphine oxide, 1,1'-dinaphthylphosphine oxide, bis(4-phenylphenyl)phosphine oxide, 2,2'-bis-(2-naphthyl)phosphine oxide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and diethyl phosphite.

[0016] Furthermore, in the above method, the photocatalyst is a non-metallic dye. For example, eosin Y, fluorescein, rhodamine B, Acr-MesClO4, 4CzIPN, Ir(ppy)3, Ir[dCF3(m)ppy]2(bpy)PF6, Ru(bpy)3(PF6)2.

[0017] Furthermore, in the above method, the organic solvent is selected from halogen-containing polar solvents, aromatic polar solvents, nitrile solvents, amide solvents, alcohol solvents, ether solvents, sulfone solvents, or aromatic solvents.

[0018] Furthermore, in the above method, the halogen-containing polar solvent is selected from dichloromethane, chloroform, etc. The aromatic polar solvent is selected from xylene, pyridine, or chlorobenzene, etc. The nitrile solvent is selected from acetonitrile or propionitrile, etc. The amide solvent is selected from N,N-dimethylformamide, N,N-dimethylacetamide, etc. The alcohol solvent is selected from methanol or ethanol, etc. The ether solvent is selected from anisole, diethyl ether, or 1,4-dioxane, etc. The sulfone solvent is selected from dimethyl sulfoxide, etc. The aromatic solvent is selected from toluene or benzene, etc.

[0019] More preferably, in the above method, the organic solvent is selected from pyridine, anisole, chlorobenzene, or N,N-dimethylformamide.

[0020] Furthermore, in the above method, the reaction temperature is room temperature (e.g., 0-25℃, 5-25℃, 10-25℃, 15-25℃, 20-25℃). The reaction time is 24-72 h.

[0021] Furthermore, in the above method, the ratio of the organic solvent to the phosphorus compound is 2-5 mL: 1 mmol.

[0022] Furthermore, in the above method, the illumination is achieved using an LED light source. The light source is an LED lamp: involving a wavelength ranging from 200nm to 900nm in the ultraviolet-visible-infrared region, and a power range of 0-100W.

[0023] Furthermore, the above method also includes purifying the reaction product. The specific purification method can be determined by those skilled in the art using conventional techniques. For example, the purification process may include filtering the reaction solution after the reaction is complete and rinsing the filter residue with an organic solvent. The organic solvent may include acetonitrile. The purification process may also include drying (e.g., using anhydrous sodium sulfate) and evaporating the solvent.

[0024] In another aspect, the present invention also provides a flame-retardant epoxy resin material, which uses the aforementioned bisphosphine oxide compound as a flame retardant.

[0025] Preferably, the above-mentioned flame-retardant epoxy resin material comprises the following components in its raw materials: bisphenol A diglycidyl ether, diaminodiphenylmethane, and bisphosphine oxides.

[0026] More preferably, the above-mentioned flame-retardant epoxy resin material comprises the following components in parts by weight: 30-48 parts of bisphenol A diglycidyl ether, 5-14 parts of diaminodiphenylmethane, and 1-4 parts of bisphosphine oxide compound.

[0027] In another aspect, the present invention provides a polybisphosphine oxide compound obtained by polymerization of the aforementioned bisphosphine oxide compound (the bisphosphine oxide compound undergoes a simple and classic Friedel-Crafts polycondensation), wherein R1, R2, R3, and R4 of the aforementioned bisphosphine oxide compound may be the same or different, and each is independently a substituted or unsubstituted C. 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkyl groups. The polybisphosphonic oxide compounds obtained in this invention can be used as anti-aging agents.

[0028] Furthermore, the polybisphosphine oxide compound is obtained by using the aforementioned bisphosphine oxide compound and The reaction yields C1, R2, R3, R4, and R, where R1, R2, R3, R4, and R may be the same or different, and each is independently a substituted or unsubstituted C. 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkyl group.

[0029] Preferably, the above-mentioned polybisphosphine oxide compounds are as shown in formula (III-1), (III-2), (III-3) or (III-4):

[0030] ;

[0031] Each of R1, R2, R3, R4, and R is either the same or different, and each is independently a substituted or unsubstituted C. 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkyl group.

[0032] Furthermore, each of R1, R2, R3, R4 and R is the same or different, and each is independently a substituted or unsubstituted phenyl group; the substituents of the phenyl group are F, Cl, Br, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy, ethoxy, n-propoxy, isopropoxy or tert-butoxy.

[0033] Furthermore, each of R1, R2, R3, R4, and R is the same or different, and each independently is phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 3,5-di-tert-butylphenyl, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, o-ethoxyphenyl, m-ethoxyphenyl, p-ethoxyphenyl, o-fluorophenyl, m-fluorophenyl, p-fluorophenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, o-bromophenyl, m-bromophenyl, p-bromophenyl, o-nitrophenyl, m-nitrophenyl, p-nitrophenyl, o-cyanophenyl, m-cyanophenyl, or p-cyanophenyl.

[0034] Furthermore, each n is independently 1-100.

[0035] More preferably, the above-mentioned polybisphosphine oxide compound is selected from the following compounds 21-24:

[0036] .

[0037] Furthermore, each n is independently 1-100.

[0038] The polybisphosphine oxide compound of the present invention, as shown in formula (III), is obtained by simple and classic Friedel-Crafts polymerization of an aryl-containing bisphosphine oxide compound and is used for anti-aging purposes. The polybisphosphine oxide compound is obtained by a classic Friedel-Crafts acyl polymerization reaction according to the following formula. The polybisphosphine oxide compound can be used as an anti-aging agent in polyurethane flexible foam. For example, the polybisphosphine oxide compound obtained by condensation polymerization of a bisphosphine oxide compound with terephthaloyl chloride is used as an anti-aging agent. An exemplary reaction equation is shown in the following schematic diagram:

[0039]

[0040] In another aspect, the present invention provides an anti-aging polyurethane material, which uses polybisphosphine oxides as anti-aging agents.

[0041] Preferably, the raw materials of the above-mentioned anti-aging polyurethane material include the following components: polyether polyol, diphenylmethane diisocyanate, and polybisphosphine oxide compound.

[0042] Preferably, the above-mentioned anti-aging polyurethane material comprises the following components in parts by weight: 90-110 parts of polyether polyol, 30-50 parts of diphenylmethane diisocyanate, and 5-25 parts of polybisphosphine oxide compound.

[0043] Preferably, the above-mentioned anti-aging polyurethane material comprises the following components in parts by weight: 90-110 parts of polyether polyol (330N), 30-50 parts of diphenylmethane diisocyanate (MDI-2412), 5-25 parts of polybisphosphine oxide compound, 1-5 parts of distilled water, 1-5 parts of surfactant (DC2525), 1-5 parts of triethanolamine (TEOA), 0.1-1 parts of catalyst triethylenediamine (A1), and 0.1-1 parts of dilauryl dibutyltin (T12).

[0044] When the amount of the polybisphosphine oxide anti-aging agent described herein is 5 parts, the tensile strength, elongation at break, and compressive strength of the anti-aging polyurethane material are all improved to a certain extent. Furthermore, compared with the pure foam, it exhibits better mechanical properties after acid aging, alkali aging, salt aging, UV aging, and heat aging. The aging treatment includes: acid aging by soaking in 0.1 mol / L HCl solution for 12 h, 24 h, 48 h, or 72 h; alkali aging by soaking in 0.1 mol / L NaOH solution for 12 h, 24 h, 48 h, or 72 h; salt aging by soaking in saturated NaCl solution for 12 h, 24 h, 48 h, or 72 h; UV aging by irradiation under a UVA-351 UV lamp for 12 h, 24 h, 48 h, or 72 h; and heat aging by treatment in an oven at 125℃ for 16 h, 24 h, or 48 h.

[0045] The bisphosphonium oxide compounds prepared by this invention, and the polybisphosphonium oxide compounds obtained by polymerization thereof, are a very important class of compounds with wide applications in pharmaceutical, pesticide chemistry and materials chemistry. They can also be used as anti-aging agents and flame retardants in materials.

[0046] The beneficial effects of the bisphosphine oxides of this invention:

[0047] First, the compounds and their preparation method provided by this invention use readily available phosphine compounds as raw materials and utilize visible light catalysis. This method is simple to operate, has a short synthetic route, and can be used to synthesize bisphosphine oxide compounds with diverse structures, making it suitable for large-scale preparation. This is of great significance for the preparation and application of such compounds. Second, this invention utilizes bisphosphine oxide compounds to effectively achieve flame retardancy in various polymer materials, including polyurethane and epoxy resin. It has the advantage of achieving high flame retardant performance with low flame retardant addition. Only 2wt% of flame retardant can achieve a limiting oxygen index ≥35% for epoxy resin flame-retardant materials and pass the UL94 V-0 level. Finally, the use of bisphosphine oxide compounds to synthesize poly(bisphosphine oxide) polymers shows good anti-aging properties in polyurethane materials. With only 5 parts added, the mechanical properties, including but not limited to tensile strength and compressive strength, are significantly stronger than the aged pure samples after photoaging, thermal aging, acid aging, salt aging, and alkali aging. Detailed Implementation

[0048] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0049] Example 1: 1,1,2,2-Tetraphenyl-1,2-diphosphine 1,2-dioxide (Compound 1)

[0050] Diphenylphosphine oxide (101 mg, 0.5 mmol) and photocatalyst 4CzIPN (3.9 mg, 0.0005 mmol) were placed in a photoreaction tube containing a stir bar, and 2 mL of acetonitrile solvent was added. The reaction was stirred at room temperature for 24 hours. After the reaction was completed, the residue was filtered to obtain a pale yellow residue, which was washed with 6-10 mL of acetonitrile and dried to obtain a white solid, 99.5 mg, 99% yield. 1 H NMR (400 MHz, DMSO) δ7.74 (dd, J = 11.3, 7.5 Hz, 8H), 7.48 (dd, J = 13.2, 6.1 Hz, 12H). 31 P NMR (162 MHz, DMSO) δ 23.12. 13 C NMR (101 MHz, DMSO) δ 136.24, 134.90, 131.84, 131.40, 128.86. HRMS (ESI) theoretical values: [(C 24 H 20 O2P2)+Na] + m / z 425.0831, experimental value: 425.0842.

[0051] Example 2: 1,1,2,2-Tetra(4-methoxyphenyl)-1,2-diphosphine 1,2-dioxide (Compound 2)

[0052] Following the method in Example 1, 1,1,2,2-tetra(4-methoxyphenyl)phosphine oxide was obtained from bis(4-methoxyphenyl)phosphine oxide as a raw material, yielding 103.2 mg of a white solid in 79% yield. 1 H NMR (400MHz, DMSO) δ 7.64 (dd, J = 11.1, 8.7 Hz, 8H), 7.01 (d, J = 6.9 Hz, 8H), 3.77 (s, 12H). 31 P NMR (162 MHz, DMSO) δ 24.19 (s). 13 C NMR (101 MHz, DMSO) δ 161.99, 133.17, 127.85, 126.44, 114.33, 55.68. HRMS (ESI) theoretical values: [(C 28 H 28 O6P2)+Na] + m / z 545.1253, experimental value: 545.1260.

[0053] Example 3: 1,1,2,2-Tetra(4-chlorophenyl)-1,2-diphosphine 1,2-dioxide (Compound 3)

[0054] Following the method described in Example 1, using bis(4-chlorophenyl)phosphine oxide as a starting material, 1,1,2,2-tetra(4-chlorophenyl)-1,2-diphosphine 1,2-dioxide was obtained, yielding 103.5 mg of a white solid in 76% yield. 1 H NMR (400 MHz, DMSO) δ 7.77 – 7.68 (m, 8H), 7.53 (dd, J = 8.4, 2.5 Hz, 8H). 31 P NMR (162 MHz, DMSO) δ 21.40 (s). 13 C NMR (101 MHz, DMSO) δ 137.20, 134.66, 133.30, 129.15. HRMS (ESI) theoretical values: [(C 24 H 20 O2P2C l4 )+NH4] + m / z 555.9718, experimental value: 555.9772.

[0055] Example 4: 1,1,2,2-Tetra(4-bromophenyl)-1,2-diphosphine 1,2-dioxide (Compound 4)

[0056] Following the method in Example 1, using bis(4-bromophenyl)phosphine oxide as a raw material, 1,1,2,2-tetra(4-bromophenyl)-1,2-diphosphine 1,2-dioxide was obtained as a pale yellow solid, 162.5 mg, in 90% yield. 1 H NMR (400 MHz, DMSO) δ 7.73 – 7.59 (m, 16H). 31 P NMR (162 MHz, DMSO) δ 21.62 (s). 13 C NMR (101 MHz, DMSO) δ 135.03, 133.52, 132.08, 126.20. HRMS (ESI) theoretical value: C 24 H 16 Br4O2P2 m / z 713.7359, experimental value: 713.7368.

[0057] Example 5: 1,1,2,2-Tetra[3,5-Di(tert-butyl)phenyl]-1,2-diphosphine 1,2-dioxide (Compound 5)

[0058] Following the method described in Example 1, 1,1,2,2-tetratetra[3,5-di(tert-butylphenyl)phenyl]-1,2-diphosphine 1,2-dioxide was obtained from bis(3,5-di-tert-butylphenyl)phosphine as a raw material. The resulting product was a white solid, yielding 201.8 mg in 95% yield. 1 H NMR(400 MHz, DMSO) δ 7.63 (dd, J = 12.7, 1.6 Hz, 8H), 7.52 (s, 4H), 1.30 (s,72H). 31 P NMR (162 MHz, DMSO) δ 26.78 (s). 13 C NMR (101 MHz, DMSO) δ 150.62, 134.90, 133.57, 125.34, 35.01, 31.52. HRMS (ESI) theoretical values: [(C 56 H 84 O2P2)+Na] + m / z 874.5839, experimental value: 874.5848.

[0059] Example 6: 1,1,2,2-Tetra(3,5-dimethylphenyl)-1,2-diphosphine 1,2-dioxide (Compound 6)

[0060] Following the method in Example 1, 1,1,2,2-tetra(3,5-dimethylphenyl)phosphine oxide was obtained as a raw material, yielding 104.5 mg of a white solid in 81% yield. 1 H NMR (400 MHz, DMSO) δ 7.31 (d, J = 12.3 Hz, 8H), 7.03 (s, 4H), 2.24 (s, 24H). 31 PNMR (162 MHz, DMSO) δ 26.12 (s). 13 C NMR (101 MHz, DMSO) δ 137.76, 135.25, 133.91, 133.12, 128.82, 21.29. HRMS (ESI) theoretical values: ([C 32 H 36 O2P2]+Na) + m / z 537.2083, Experimental value: 537.2085.

[0061] Example 7: 1,1,2,2-Tetra(naphthyl-1-yl)-1,2-diphosphine 1,2-dioxide (Compound 7)

[0062] Following the method in Example 1, 1,1'-dinaphthylphosphine oxide was used as a raw material to obtain 1,1,2,2-tetra(naphthyl-1-yl)-1,2-diphosphine 1,2-dioxide, which was a pale yellow solid, 108.2 mg, with a yield of 72%. 1 H NMR (400 MHz, DMSO)δ 8.60 (d, J = 4.7 Hz, 4H), 8.21 (dd, J = 14.7, 6.6 Hz, 4H), 8.11 (d, J = 7.8Hz, 4H), 7.96 (s, 4H), 7.64 (s, 4H), 7.49 (d, J = 3.1 Hz, 8H). 31 P NMR (162MHz, DMSO) δ 24.18 (s). 13C NMR (101 MHz, DMSO) δ 133.73, 133.07, 132.70, 132.35, 131.05, 129.31, 127.30, 126.93, 126.63, 125.41. HRMS (ESI) theoretical value: [(C 40 H 28 O2P2)+Na] + m / z 625.1457, experimental value: 625.1458.

[0063] Example 8: 1,1,2,2-Tetra([1,1'-biphenyl]-4-yl)-1,2-diphosphine 1,2-dioxide (Compound 8)

[0064] Following the method in Example 1, using bis(4-phenylphenyl)phosphine oxide as a raw material, 1,1,2,2-tetra([1,1'-biphenyl]-4-yl)-1,2-diphosphine 1,2-dioxide was obtained, white solid 78.9, yield 89%. 1 H NMR (400 MHz, DMSO) δ 7.88 – 7.80 (m, 9H), 7.79 – 7.72 (m, 7H), 7.68 (dd, J = 12.5, 7.4 Hz, 8H), 7.47 (dd, J = 14.6, 7.3 Hz, 8H), 7.38 (t, J = 7.3 Hz, 4H). 31 P NMR (162MHz, DMSO) δ 23.42 (s), 18.09 (s). 13 C NMR (101 MHz, DMSO) δ 143.57, 139.69, 134.83, 133.48, 132.05, 129.46, 128.56, 127.32. HRMS (ESI) theoretical values: [(C 48 H 36 O2P2)+H] + m / z 707.2263, experimental value: 707.2272.

[0065] Example 9: 1,1,2,2-Tetra(naphthyl-2-yl)-1,2-diphosphine 1,2-dioxide (Compound 9)

[0066] Following the method in Example 1, using 2,2'-bis-(2-naphthyl)phosphine oxide as the raw material, 1,1,2,2-tetra(naphthyl-2-yl)-1,2-diphosphine 1,2-dioxide was obtained, a pale yellow solid of 127.8 mg, in 80% yield.1 H NMR (400 MHz, DMSO) δ 8.47 (d, J = 13.8 Hz, 4H), 8.07 (d, J = 7.5 Hz, 4H), 8.01-7.91 (m,8H), 7.81 (t, J = 9.2 Hz, 4H), 7.59 (dt, J = 13.3, 6.6 Hz, 8H). 31 P NMR (162MHz, DMSO) δ 23.44 (s). 13 C NMR (101 MHz, DMSO) δ 134.47, 133.45, 132.11, 129.27, 128.84-128.29, 128.15, 127.36, 127.07, 40.60, 40.4, 40.12, 39.91, 39.70, 39.49, 39.28. HRMS (ESI) theoretical values: [(C 40 H 28 O2P2)+H] + m / z 603.1637, experimental value: 603.1638.

[0067] Example 10: [6,6'-Bidibenzo[c,e][1,2]oxaphosphacyclohexene] 6,6'-dioxide (Compound 10)

[0068] Following the method in Example 1, using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as a starting material, [6,6'-bibenz[c,e][1,2]oxaphosphacyclohexene] 6,6'-dioxide was obtained, yielding 67.1 mg of yellow solid in 62% yield. 1 H NMR (400 MHz, DMSO) δ 8.19 - 8.11 (m, 2H), 7.78 (ddd, J = 23.9, 15.3,8.0 Hz, 5H), 7.56 (ddd, J = 18.9, 11.4, 5.1 Hz, 4H), 7.48 - 7.41 (m, 2H),7.35-7.23 (m, 3H). 31 P NMR (162 MHz, DMSO) δ 5.98 (s). 13C NMR (101 MHz, DMSO) δ 133.82, 130.98, 128.76, 127.25, 127.16, 126.76, 126.61, 123.99, 122.74, 122.63, 121.13, 118.42. HRMS (ESI) theoretical values: [(C 24 H 16 O4P2)+H] + m / z 431.0597, experimental value: 431.0603.

[0069] Example 11: Tetra(2,2,2-trifluoroethyl) diphosphate (Compound 11)

[0070] Following the method in Example 1, tetra(2,2,2-trifluoroethyl) diphosphate was obtained from bis(2,2,2-trifluoroethyl) phosphonate as a raw material, yielding 93.6 mg of a pale yellow liquid at a yield of 76%. 1 H NMR (400 MHz, DMSO) δ 4.54– 3.80 (m, 1H). 31 P NMR (162 MHz, DMSO) δ -3.15 (s). 19 F NMR (376 MHz, DMSO) δ-74.00 (s). 13 C NMR (101 MHz, DMSO) δ 124.9 (qd, J P-C = 277.9, J F-C =10.5 Hz), 62.3 (qd, J F-C = 34.5, J P-C =4.6 Hz). HRMS (ESI) theoretical value: [(C8H8F 12 O6P2)+Na] + m / z 512.9497, experimental value: 512.9498.

[0071] Example 12: Tetraethyl diphosphate (Compound 12)

[0072] Following the method in Example 1, tetraethyl pyrophosphate was obtained from diethyl phosphite as a raw material, yielding 31.8 mg of a yellow liquid at a yield of 46%. 1 H NMR (400 MHz, DMSO) δ 3.67 – 3.59 (m, 8H), 1.08 (t, J =7.1 Hz, 12H). 31P NMR (162 MHz, DMSO) δ -0.64 (s). 13 C NMR (101 MHz, DMSO) δ 59.67, 59.61, 17.15, 17.08. HRMS (ESI) theoretical value: [(C8H 20 O6P2)+Na] + m / z 297.0627, experimental value: 297.0624.

[0073] Example 13: Tetraphenyldiphosphate (Compound 13)

[0074] Following the method in Example 1, tetraphenyl diphosphate was obtained from diphenylphosphonate as a raw material, yielding 71.8 mg of a yellowish-brown liquid at a yield of 62%. 1 H NMR (400 MHz, DMSO) δ 7.76 (dd, J = 15.7, 8.6 Hz,1H), 7.46 (t, J = 7.8 Hz, 2H), 7.29 (t, J = 8.3 Hz, 3H), 7.22 (t, J = 7.8 Hz,4H), 7.13 (d, J = 8.0 Hz, 4H), 6.96 (t, J = 7.2 Hz, 2H), 6.83 (d, J = 8.6 Hz, 1H). 31 P NMR (162 MHz, DMSO) δ -11.60 (s), -17.25 (s). 13 C NMR (101 MHz, DMSO)δ 129.3, 129.2 (d, J P-C = 552.5 Hz), 126.6 (d, J P-C = 844.3 Hz), 120.37 (t, J P-C = 4.9 Hz). HRMS (ESI) theoretical value: C 24 H 20 O6P2m / z 466.0735, experimental value: 466.0728.

[0075] Example 14: 6-[bis(3,5-dimethylphenyl)phosphonyl]dibenzo[c,e][1,2]oxaphosphacyclohexane 6-oxide (Compound 14)

[0076] Following the method described in Example 1, 6-[bis(3,5-dimethylphenyl)phosphine]dibenzo[c,e][1,2]oxaphosphacyclohexane 6-oxide was obtained from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and bis(3,5-dimethylphenyl)phosphine oxide as raw materials, yielding 158.6 mg of white solid in 66% yield. 1 H NMR (400 MHz, DMSO) δ 8.10(d, J = 7.1 Hz, 1H), 7.81 (s, 1H), 7.72 (t, J = 7.4 Hz, 1H), 7.54 (s, 1H),7.42 (t, J = 7.2 Hz, 1H), 7.36 – 7.26 (m, 1H), 7.23 (d, J = 7.8 Hz, 1H), 7.11(s, 1H), 2.28 (s, 1H). 31 P NMR (162 MHz, DMSO) δ 24.37 (s), 5.68 (s). 13 C NMR (101 MHz, DMSO) δ 150.5, 138.0, 137.9, 136.0, 134.7, 133.2, 132.9, 130.7,129.3, 129.0, 128.9 (d, J P-C = 9.5 Hz), 128.6 (d, J P-C = 11.9 Hz), 126.0,124.7, 123.3 (d, J P-C = 6.3 Hz), 120.5 (d, J P-C = 7.4 Hz), 21.3. HRMS (ESI) theoretical value: [(C 28 H 25 O3P2)-H] - m / z 471.1284, experimental value: 471.1273.

[0077] Example 15: 1,1-bis(3,5-dimethylphenyl)-2,2-bis(naphthyl-2-yl)diphosphine 1,2-dioxide (Compound 15)

[0078] Following the method in Example 1, 1,1-bis(3,5-dimethylphenyl)phosphine oxide and 2,2'-bis-(2-naphthyl)phosphine oxide were used as raw materials to obtain 1,1-bis(3,5-dimethylphenyl)-2,2-bis(naphthyl-2-yl)diphosphine 1,2-dioxide, a yellow-brown solid, in a yield of 153.8 mg, at 86%. 1H NMR (400 MHz, DMSO) δ 8.46 (d, J = 13.7 Hz, 1H), 8.04 (d, J = 7.6 Hz, 1H), 7.99 – 7.90 (m, 1H), 7.80 (t, J = 9.2 Hz, 1H), 7.65– 7.50 (m, 1H), 7.33 (d, J = 12.2 Hz, 1H), 7.10 (s, 1H), 2.25 (s, 1H). 31 P NMR (162 MHz, DMSO) δ 23.97 (s), 23.07 (s). 13 C NMR (101 MHz, DMSO) δ 137.9 (d,J P-C = 13.2 Hz), 135.5 (d, J P-C = 133.7 Hz), 134.4 (d, J P-C = 2.1 Hz), 133.7, 133.2 (d, J P-C = 2.3 Hz), 132.6 (d, J P-C = 2.0 Hz), 132.5 (d, J P-C = 21.2 Hz), 129.3, 129.0 (d, J P-C = 9.8 Hz), 128.5 (d, J P-C = 12.4 Hz), 128.4, 128.1,127.3, 127.2 (d, J P-C = 10.7 Hz), 21.3. HRMS (ESI) theoretical value: [(C 36 H 32 O2P2)+H] + m / z 559.1951, experimental value: 559.1953.

[0079] Example 16: 1,1-Di(naphthyl-1-yl)-2,2-Di(naphthyl-2-yl)diphosphine 1,2-dioxide (Compound 16)

[0080] Following the method in Example 1, 1'-dinaphthylphosphine oxide raw material and 2,2'-bis-(2-naphthyl)phosphine oxide were used.

[0081] Using it as a raw material, 196.7 mg of a yellowish-brown solid was obtained, with a yield of 65%. 1H NMR (400 MHz, DMSO) δ 8.62(d, J = 5.1 Hz, 1H), 8.49 (d, J = 13.7 Hz, 1H), 8.34 (s, 1H), 8.22 (dd, J =15.2, 6.4 Hz, 1H), 8.13 – 8.01 (m, 2H), 7.94 (dd, J = 17.1, 7.8 Hz, 3H), 7.86– 7.77 (m, 1H), 7.58 (dd, J = 13.7, 7.0 Hz, 3H), 7.47 (d, J = 7.2 Hz, 1H). 31 PNMR (162 MHz, DMSO) δ 23.08 (s), 17.13 (s). 13 C NMR (101 MHz, DMSO) δ 134.5(d, J P-C = 2.1 Hz), 133.9 (d, J P-C = 2.4 Hz), 133.8, 133.7, 133.1, 133.0 (d,J P-C = 2.7 Hz), 132.6 (d, J P-C = 8.1 Hz), 132.4 (d, J P-C = 11.4 Hz), 130.5 (d,J P-C = 160.9 Hz), 129.3, 128.6 (d, J P-C = 12.2 Hz), 128.4, 127.7 (d, J P-C = 83.3Hz), 127.2 (d, J P-C = 2.9 Hz), 127.1, 127.0 (d, J P-C = 4.7 Hz), 126.6, 125.8 (d, J) P-C = 14.3 Hz), 125.4 (d, J P-C = 13.8 Hz), 125.2 (d, J P-C = 7.5 Hz). HRMS(ESI) theoretical value: [(C 40 H 28 O2P2)+H] + m / z 603.1638, experimental value: 603.1638.

[0082] Example 17: 1,1-bis(3,5-dimethylphenyl)-2,2-diphenyldiphosphine 1,2-dioxide (Compound 17)

[0083] Following the method in Example 1, 1,1-bis(3,5-dimethylphenyl)-2,2-diphenyldiphosphine 1,2-dioxide was obtained from diphenylphosphine oxide and bis(3,5-dimethylphenyl)phosphine oxide as raw materials, yielding 191.5 mg of white solid in 84% yield. 1 H NMR (400 MHz, DMSO) δ 7.78 – 7.68 (m, 1H), 7.43 (d, J = 7.1 Hz, 1H), 7.40 (dd, J = 7.5, 2.9 Hz, 1H), 7.33 (d, J = 12.3 Hz, 1H), 7.05 (s, 1H), 2.26(s, 1H). 31 P NMR (162 MHz, DMSO) δ 25.80 (s), 24.66 (s). 13 C NMR (101 MHz, DMSO) δ 138.0, 137.8, 135.4 (d, J P-C = 132.8 Hz), 133.2, 131.8, 131.4 (d, J P-C = 9.6 Hz), 128.9 (d, J P-C = 23.4 Hz), 128.9, 21.3. HRMS (ESI) theoretical value: [(C 28 H 28 O2P2)+H] + m / z 459.1638, experimental value: 459.1630.

[0084] Example 18: 1,1-Di(naphthyl-1-yl)-2,2-diphenyldiphosphine 1,2-dioxide (Compound 18)

[0085] Following the method in Example 1, using diphenylphosphine oxide and 1,1'-dinaphthylphosphine oxide as raw materials, 1,1-bis(naphthyl-1-yl)-2,2-diphenyldiphosphine 1,2-dioxide was obtained, yielding 225.3 mg of a pale yellow solid in 90% yield. 1H NMR(400 MHz, DMSO) δ 8.65 – 8.54 (m, 1H), 8.21 (dd, J = 14.7, 7.4 Hz, 1H), 8.11(d, J = 8.2 Hz, 1H), 7.98 – 7.93 (m, 1H), 7.78 – 7.71 (m, 1H), 7.66 – 7.59(m, 1H), 7.51 – 7.45 (m, 1H). 31 P NMR (162 MHz, DMSO) δ 24.17 (s), 23.44 (s). 13 C NMR (101 MHz, DMSO) δ 135.4 (d, J P-C = 134.6 Hz), 133.7 (d, J P-C = 10.3 Hz), 133.1 (d, J P-C = 2.8 Hz), 133.0, 132.7 (d, J P-C = 10.8 Hz), 131.9 (d, J P-C = 2.4Hz), 131.7 (d, J P-C = 131.0 Hz), 131.4 (d, J P-C = 10.0 Hz), 130.2 (d, J P-C =237.7 Hz), 130.1 (d, J P-C = 260.2 Hz), 129.3, 127.0 (d, J P-C = 66.7 Hz), 126.9 (d, J P-C = 4.6 Hz), 125.4 (d, J P-C = 13.8 Hz). HRMS (ESI) theoretical value: [(C32H25O2P2)+H]+ m / z 503.1325, experimental value: 503.1335.

[0086] Example 19: 1,1-Di(naphthyl-2-yl)-2,2-diphenyl-1,2-diphosphine 1,2-dioxide (Compound 19)

[0087] Following the method in Example 1, using diphenylphosphine oxide and 2,2'-bis-(2-naphthyl)phosphine oxide as raw materials, 1,1-bis(naphthyl-2-yl)-2,2-diphenyl-1,2-diphosphine 1,2-dioxide was obtained, a pale yellow solid of 202.6 mg, in 81% yield.1 H NMR (400 MHz, DMSO) δ 8.45 (dd, J = 20.4, 9.0 Hz, 2H), 8.06 (dd, J =14.0, 6.7 Hz, 2H), 8.01 – 7.89 (m, 4H), 7.85 – 7.69 (m, 8H), 7.67 – 7.42 (m,12H). 31 P NMR (162 MHz, DMSO) δ 23.47 (d, J = 14.2 Hz). 13 C NMR (101 MHz, DMSO) δ 135.4 (d, J P-C = 134.7 Hz), 134.5 (d, J P-C = 2.2 Hz), 133.4, 132.7,132.6, 132.3 (d, J P-C = 36.0 Hz), 131.9 (d, J P-C = 2.5 Hz), 130.2 (d, J P-C =238.3 Hz), 130.1 (d, J P-C = 260.7 Hz), 129.3, 128.6 (d, J P-C = 12.3 Hz), 128.5, 127.8 (d, J P-C = 79.8 Hz), 127.1 (d, J P-C = 10.6 Hz). HRMS (ESI) theoretical value: [(C 32 H 24 O2P2)+Na] + m / z 525.1144, experimental value: 525.1143.

[0088] Example 20: 6-(diphenylphospho)dibenzo[c,e][1,2]oxaphosphacyclohexadiene 6-oxide (Compound 20)

[0089] Following the method in Example 1, using diphenylphosphine oxide and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as raw materials, 6-(diphenylphosphoyl)dibenzo[c,e][1,2]oxaphosphacyclohexadiene 6-oxide was obtained as a pale yellow solid, yielding 153.4 mg in 74% yield. 1H NMR (400 MHz, DMSO) δ 7.73 (dd, J = 11.9, 6.8 Hz, 1H), 7.55 – 7.45 (m, 1H). 31 P NMR (162 MHz, DMSO) δ 23.42 (s), 5.92 (s). 13 CNMR (101 MHz, DMSO) δ 150.4 (d, J P-C = 6.9 Hz), 136.1, 134.7, 133.1 (d, J P-C =2.0 Hz), 131.9 (d, J P-C = 2.7 Hz), 131.4, 131.3, 130.9, 129.3 (d, J P-C = 9.3Hz), 129.0, 128.9, 126.1, 124.9, 124.7, 123.2 (d, J P-C = 11.7 Hz), 120.5 (d,J P-C = 6.0 Hz). HRMS (ESI) theoretical value: [(C 24 H 18 O3P2)-H] - m / z 415.0658 Experimental value: 415.0655.

[0090] Example 21: Poly(4-(4-(phenyl(phenyl-p-methylphenyl)phosphoryl)phosphoryl)benzoyl)phenyl)ethyl-1-one (Compound 21)

[0091] Under a nitrogen atmosphere, AlCl3 (6.5 g) was added to a three-necked flask, followed by dichloroethane (DCE, 20 mL). The flask was placed in an ice bath at 0 °C. A mixture of N,N-dimethylformamide (DMF, 0.5 mL) and dichloroethane (10 mL) was added dropwise to the flask until the solution became clear. The cooling bath temperature was then adjusted to −10 °C. Compound 1 (11 mmol, 4.02 g) and terephthaloyl chloride (TPC, 10 mmol, 2.03 g) were added to the reaction mixture. The reaction was carried out at this low temperature for 1 hour. Subsequently, the reaction mixture was heated to 25 °C and stirred for 48 hours. The reaction was terminated by the slow addition of methanol (30 mL), accompanied by the emission of a small amount of white fumes and the precipitation of a white solid. The solid was collected by filtration and washed successively with dilute hydrochloric acid, formic acid, and water until the filtrate was neutral. The resulting solid was further washed with a mixture of dichloromethane (DCM) and methanol, dried, and ground into a white powder. The yield was 99%.

[0092] Application Example 1

[0093] This embodiment provides a flame-retardant epoxy resin material comprising the following components: 78.4 g of bisphenol A diglycidyl ether, 19.6 g of diaminodiphenylmethane, and 2 g of flame retardant, wherein the flame retardant is 1,1,2,2-tetraphenyl-1,2-diphosphine 1,2-dioxide (compound 1) prepared above.

[0094] Experimental verification showed that when the flame retardant addition amount was 2wt% of the total mass, the limiting oxygen index of the obtained flame-retardant epoxy resin material was ≥38%. The specific steps are as follows: The flame retardant performance of the material was evaluated using a JF-3 oxygen index tester from Nanjing Jiangning Analytical Co., Ltd., according to GB / T 2406.3-2022 standard. The test specimen size was 130 mm × 6.5 mm × 3.2 mm; the ignition flame length was 15 mm; the burning time was less than 3 minutes and the burning length was less than 50 mm; the test result was a value that passed stably for more than 3 tests. In addition, the material underwent a vertical burning (UL-94) test using a CZF-3 vertical burning tester from Nanjing Jiangning Analytical Co., Ltd., according to GB / T2408-2021 standard. The test specimens were 130 mm × 13 mm × 3.2 mm in size. A Bunsen burner (flame height 20.0 ± 1.0 mm) was used to apply a flame to the midpoint of the lower edge of the specimen for 10 ± 0.5 s. Each group of five specimens underwent two separate flame ignition contacts. After removing the flame, the flaming time (t1 and t2) and drip ignition were recorded twice. The burning time for each specimen was the average of the five parallel tests. This indicates that the diphosphorus oxide flame retardant prepared in this invention has the advantage of achieving high flame retardant performance with low addition amounts.

[0095] Application Example 2

[0096] Polyurethane foam was prepared using a one-step molding process. The density was controlled within the range of 60-70 kg·m⁻³ by adjusting the formulation to eliminate fluctuations in mechanical properties caused by density variations. Polyether polyol (330N), distilled water, surfactant (DC2525), triethanolamine (TEOA), catalyst triethylenediamine (A1), dibutyltin dilaurate (T12), and anti-aging agent (compound 21) were sequentially added to a plastic beaker and stirred at 3000 rpm for 3 minutes. While continuously stirring at 3000 rpm, modified 4,4'-diphenylmethane diisocyanate (MDI-2412) was added to the mixture. Within 5 seconds of adding MDI, the resulting mixture was rapidly poured into an open plastic mold. The amount of MDI used was calculated based on the isocyanate index (NCO / OH ratio = 1.05). The foam was cured at 70 °C for 2 minutes. The specific foaming formulation is shown in Table 1.

[0097] Table 1 Formulation Table

[0098]

[0099] Experiments have shown that when the amount of anti-aging agent added is only 5 parts of 330N polyol, the mechanical properties of polyurethane foam, including but not limited to tensile strength and compressive strength, are significantly improved compared with the pure sample after photoaging, heat aging, acid aging, salt aging and alkali aging.

[0100] The specific testing methods are as follows: Tensile Test. Using the ISO 1798:2008 standard, the specimen was stretched uniformly at a specified rate, and the tensile force and elongation were recorded to derive the tensile stress-strain curve. Material parameters such as tensile strength, elongation at break, and tensile toughness of the foam were obtained. Tensile tests were conducted using an Instron 5400 universal testing machine equipped with a 500 N load cell, at a tensile speed of 500 mm / min and a load of 250 N. Additionally, a Cyclic Compressive Test was performed. Using an Instron 5400 universal testing machine equipped with a 500 N load cell, 100 cycles of compression were conducted at 50% compression deformation and a strain rate of 20 mm / min. The pressure and compression distance were recorded, and the compressive stress-strain curve was derived. In addition to obtaining the compressive strength of the foam, the corresponding compressive strength recovery rate and compressive deformation recovery rate can also be obtained. The sample size is 50×50×25 mm. 3 Each sample was measured three times. All measurements showed significantly better performance than the aged pure sample. This indicates that the poly(phosphorus oxide) polymer anti-aging agent prepared in this invention has the advantage of chemical stability.

[0101] Table 2: Comparison of tensile strength after aging

[0102]

[0103] Table 3: Comparison of compressive strength after aging

[0104]

[0105] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. The bisphosphonic oxide compound represented by formula (II): ； in, R1, R2, R3, and R4 may be the same or different, and each is independently C. 1-4 Alkoxy, halogenated C 1-4 Alkoxy, -C 1-4 alkoxy-phenyl, biphenyl, or substituted or unsubstituted C 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkyl groups; or R1 and R2 combined with P groups attached to them to form phosphenanthrene groups; or R3 and R4 combined with P groups attached to them to form phosphenanthrene groups; Furthermore, R1, R2, R3, and R4 may be the same or different, and each independently is methoxy, ethoxy, fluoromethoxy, fluoroethoxy, phenoxy, biphenyl, naphthyl, or a substituted or unsubstituted phenyl group; the substituent of the phenyl group is F, Cl, Br, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, or tert-butoxy; or R1 and R2 combined with the P group attached to them form a phosphenanthrene group; or R3 and R4 combined with the P group attached to them form a phosphenanthrene group. Furthermore, R1, R2, R3, and R4 may be the same or different, and each independently represents methoxy, ethoxy, fluoromethoxy, fluoroethoxy, phenoxy, naphth-1-yl, naphth-2-yl, biphenyl, phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 3,5-dimethylphenyl, etc. tert-butylphenyl, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, o-ethoxyphenyl, m-ethoxyphenyl, p-ethoxyphenyl, o-fluorophenyl, m-fluorophenyl, p-fluorophenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, o-bromophenyl, m-bromophenyl, p-bromophenyl, o-nitrophenyl, m-nitrophenyl, p-nitrophenyl, o-cyanophenyl, m-cyanophenyl, p-cyanophenyl; or R1 and R2 combined with P attached to them to form phosphenanthrene; or R3 and R4 combined with P attached to them to form phosphenanthrene; Furthermore, the bisphosphine oxide compound is selected from the following compounds 1-20: 。 2. The method for synthesizing the bisphosphine oxide compound according to claim 1, characterized in that: Includes the following steps: Formula (I) The phosphate compound shown is of formula (I'). The phosphate compound and photocatalyst shown react under light in the presence of an organic solvent.

3. The method for synthesizing bisphosphine oxides according to claim 2, characterized in that: The phosphorus compounds represented by formula (I) and formula (I') are each independently selected from diphenylphosphine oxide, bis(4-methoxyphenyl)phosphine oxide, bis(4-chlorophenyl)phosphine oxide, bis(4-bromophenyl)phosphine oxide, bis(3,5-di-tert-butylphenyl)phosphine oxide, bis(3,5-dimethylphenyl)phosphine oxide, 1,1'-dinaphthylphosphine oxide, bis(4-phenylphenyl)phosphine oxide, 2,2'-bis-(2-naphthyl)phosphine oxide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and diethyl phosphite.

4. The method for synthesizing bisphosphine oxides according to claim 2 or 3, characterized in that: The photocatalyst is a non-metallic dye; preferably, it is eosin Y, fluorescein, rhodamine B, Acr-MesClO4, 4CzIPN, Ir(ppy)3, Ir[dCF3(m)ppy]2(bpy)PF6 or Ru(bpy)3(PF6)2.

5. The method for synthesizing bisphosphine oxides according to any one of claims 2-4, characterized in that: The organic solvent is selected from halogen-containing polar solvents, aromatic polar solvents, nitrile solvents, amide solvents, alcohol solvents, ether solvents, sulfone solvents, or aromatic solvents; preferably, the organic solvent is selected from pyridine, anisole, chlorobenzene, or N,N-dimethylformamide.

6. The method for synthesizing bisphosphine oxides according to any one of claims 2-5, characterized in that: The reaction is carried out at a temperature of 0-25℃ or at room temperature for a time of 24-72 h.

7. The method for synthesizing bisphosphine oxides according to any one of claims 2-6, characterized in that: The illumination is achieved using an LED light source; preferably, the light source is an LED lamp: involving a light source with a wavelength from 200nm to 900nm in the ultraviolet-visible-infrared region, and a power range of 0-100W.

8. A flame-retardant epoxy resin material, characterized in that: The bisphosphine oxide compound described in claim 1 is used as a flame retardant; Preferably, the raw materials include the following components: bisphenol A diglycidyl ether, diaminodiphenylmethane, and the bisphosphine oxide compound as described in claim 1; Preferably, the raw materials include the following components in parts by weight: 30-48 parts of bisphenol A diglycidyl ether, 5-14 parts of diaminodiphenylmethane, and 1-4 parts of the bisphosphine oxide compound as described in claim 1.

9. A polybisphosphine oxide compound, characterized in that: It is obtained by polymerization of the bisphosphine oxide compound according to claim 1, wherein R1, R2, R3 and R4 of the bisphosphine oxide compound are the same or different, and each is independently a substituted or unsubstituted C. 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkoxy; Preferably, it uses the bisphosphine oxide compound as described in claim 1 and The reaction yields C1, R2, R3, R4, and R, where R1, R2, R3, R4, and R may be the same or different, and each is independently a substituted or unsubstituted C. 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkoxy; Preferred polybisphosphine oxide compounds, such as those shown in formulas (III-1), (III-2), (III-3), or (III-4): ； Each of R1, R2, R3, R4, and R is either the same or different, and each is independently a substituted or unsubstituted C. 6-14 Aryl; the C 6-14 The substituents of the aryl group are halogen, nitro, cyano, and C. 1-4 Alkyl or C 1-4 Alkoxy; Furthermore, each of R1, R2, R3, R4 and R is the same or different, and each is independently a substituted or unsubstituted phenyl group; the substituent of the phenyl group is F, Cl, Br, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy, ethoxy, n-propoxy, isopropoxy or tert-butoxy. Furthermore, each of R1, R2, R3, R4 and R is the same or different, and each independently is phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 3,5-ditert-butylphenyl, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, o-ethoxyphenyl, m-ethoxyphenyl, p-ethoxyphenyl, o-fluorophenyl, m-fluorophenyl, p-fluorophenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, o-bromophenyl, m-bromophenyl, p-bromophenyl, o-nitrophenyl, m-nitrophenyl, p-nitrophenyl, o-cyanophenyl, m-cyanophenyl or p-cyanophenyl; More preferably, the above-mentioned polybisphosphine oxide compound is selected from the following compounds 21-24: ； Furthermore, each n is independently 1-100.

10. An anti-aging polyurethane material, characterized in that: The polybisphosphine oxide compound of claim 9 is used as an anti-aging agent; Preferably, the raw materials comprise the following components: polyether polyol, diphenylmethane diisocyanate, and the polybisphosphine oxide compound as described in claim 9; Preferably, the raw materials include the following components in parts by weight: 90-110 parts of polyether polyol, 30-50 parts of diphenylmethane diisocyanate, and 5-25 parts of the polybisphosphine oxide compound as described in claim 9; More preferably, the raw materials include the following components in parts by weight: 90-110 parts of polyether polyol, 30-50 parts of diphenylmethane diisocyanate, 5-25 parts of the polybisphosphine oxide compound as described in claim 9, 1-5 parts of water, 1-5 parts of surfactant, 1-5 parts of triethanolamine, 0.1-1 parts of triethylenediamine catalyst, and 0.1-1 parts of dilauryl dibutyltin.

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