Cured product of organic phosphine-modified unsaturated polyester and epoxy resin and preparation method thereof

Abstract

This application provides a cured product of an organophosphine-modified unsaturated polyester and an epoxy resin and a preparation method. The cured product is a cross-linked polymer of the organophosphine-modified unsaturated polyester and the epoxy resin. The cured product of the organophosphine-modified unsaturated polyester and the epoxy resin exhibits excellent flame retardancy and antibacterial properties.

Description

Technical Field

[0001] The present application relates to the field of flame retardant and antibacterial materials, and specifically to a cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin and a preparation method thereof. Background Art

[0002] Unsaturated polyester resin is one of the most important thermosetting resins in the modern plastics industry. Due to its excellent mechanical properties, good corrosion resistance, low cost, low density, and high strength-to-weight ratio, it is one of the most commonly used resins in the construction, maritime, transportation, and wind energy industries. However, due to its inherent molecular structure and chemical composition, unsaturated polyester resin is extremely flammable and produces large amounts of toxic gases and smoke during combustion. To expand the application range of unsaturated polyester resins, especially to meet the requirements of some specialized applications, it is necessary to modify them to be flame-retardant while maintaining their overall performance. Chemical modification is used to introduce flame-retardant elements or flame-retardant comonomers into the molecular structure of unsaturated polyester resins, making them inherently flame-retardant. Phosphorus-containing flame-retardant comonomers are widely used in the research of reactive flame-retardant unsaturated polyesters due to their environmental friendliness and flame retardancy in both the gas and condensed phases. Summary of the Invention

[0003] The present application provides a cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin and a preparation method thereof.

[0004] On one hand, the cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin provided in the present application is a cross-linked polymer of an organic phosphine-modified unsaturated polyester and an epoxy resin.

[0005] In one embodiment, the molar ratio of the phosphine groups of the organic phosphine-modified unsaturated polyester to the epoxy groups of the epoxy resin is 1:(0.8-1.2).

[0006] In one embodiment, the epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol C epoxy resin and bisphenol fluorene epoxy resin.

[0007] In one embodiment, the organic phosphine-modified unsaturated polyester is an addition reaction product of an unsaturated polyester and diphenylphosphine.

[0008] Another aspect of the present invention provides a method for preparing a cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin, comprising:

[0009] The organic phosphine-modified unsaturated polyester and the epoxy resin are mixed and cured to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0010] In one embodiment, the molar ratio of the phosphine groups of the organic phosphine-modified unsaturated polyester to the epoxy groups of the epoxy resin is 1:(0.8-1.2).

[0011] In one embodiment, the epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol C epoxy resin and bisphenol fluorene epoxy resin.

[0012] In one embodiment, the organic phosphine-modified unsaturated polyester is a product generated by an addition reaction between an unsaturated polyester in a solvent and diphenylphosphine.

[0013] In one embodiment, the molar ratio of the double bond groups of the unsaturated polyester to the phosphine groups of the diphenylphosphine is 1:(1.2-1.5).

[0014] In one embodiment, the solvent is one or more of chloroform, tetrahydrofuran, dimethyltetrahydrofuran, and N,N-dimethylformamide.

[0015] The cured product of the organophosphine-modified unsaturated polyester and epoxy resin of the present application exhibits excellent flame retardancy due to the charcoal layer formed by phosphoric acid during combustion, which is resistant to oxidation and exhibits excellent thermal stability. Furthermore, the cured product of the organophosphine-modified unsaturated polyester and epoxy resin of the present application exhibits antibacterial properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 shows the hydrogen nuclear magnetic resonance spectrum of the unsaturated polyester prepared in Example 1;

[0017] Figure 2 The hydrogen nuclear magnetic resonance spectrum of the organic phosphine-modified unsaturated polyester prepared in Example 1 is shown;

[0018] Figure 3a A physical picture of the cured product of the organic phosphine-modified unsaturated polyester and epoxy resin prepared in Example 1 is shown;

[0019] Figure 3b A physical picture of the cured product of the organic phosphine-modified unsaturated polyester and epoxy resin prepared in Example 2 is shown;

[0020] in, Figure 3a and Figure 3b The text in the background is used to show the transmittance of the sample. DETAILED DESCRIPTION

[0021] The present application provides a cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin and a preparation method thereof.

[0022] On one hand, the cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin provided in the present application is a cross-linked polymer of an organic phosphine-modified unsaturated polyester and an epoxy resin.

[0023] This application introduces an organic phosphine into an unsaturated polyester, which is then ring-opened copolymerized with an epoxy resin. The phosphorus-containing groups in the system undergo a ring-opening reaction with the epoxy groups in the resin, increasing the degree of crosslinking and improving the thermal stability of the heat-curing epoxy resin. Furthermore, the introduction of the organic phosphine enhances the flame retardancy and antibacterial properties of the epoxy resin.

[0024] In one embodiment, the molar ratio of the phosphine groups of the organic phosphine-modified unsaturated polyester to the epoxy groups of the epoxy resin is 1:(0.8-1.2).

[0025] Epoxy resin is a high-performance synthetic resin that exhibits excellent mechanical, adhesive, electrical, and insulating properties after curing. It also offers excellent chemical stability and dimensional stability, is easy to process, exhibits good stress transfer, and is inexpensive. However, due to the molecular structure of epoxy resin, it has poor flame retardancy and is easily ignited and burned in the presence of flames. General epoxy resins have an oxygen index (LOI) of approximately 19.8%, making them flammable. To improve their fire safety and expand their application range, flame retardant modification is necessary. By introducing phosphorus-containing groups into the molecular structure of the curing agent, and utilizing the active groups of the phosphorus-containing compound to undergo a ring-opening reaction with the epoxy groups or active epoxides of the resin, the flame retardancy and thermal stability of the cured epoxy resin system are improved.

[0026] In one embodiment, the epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol C epoxy resin and bisphenol fluorene epoxy resin.

[0027] In one embodiment, the organic phosphine-modified unsaturated polyester is an addition reaction product of an unsaturated polyester and diphenylphosphine.

[0028] Quaternary phosphonium salts with long-chain alkyl groups have strong antimicrobial properties. Organic polymer compounds with antimicrobial groups have advantages such as no residue, easy processing, and good chemical stability. Furthermore, polymer antimicrobial agents do not penetrate human skin and have better antimicrobial properties than small-molecule antimicrobial agents. This application introduces organic phosphines into unsaturated polyester resin systems through a quaternary phosphonium reaction with epoxy groups, effectively enhancing the system's antimicrobial properties.

[0029] Another aspect of the present invention provides a method for preparing a cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin, comprising:

[0030] The organic phosphine-modified unsaturated polyester and the epoxy resin are mixed and cured to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0031] In one embodiment, the molar ratio of the phosphine groups of the organic phosphine-modified unsaturated polyester to the epoxy groups of the epoxy resin is 1:(0.8-1.2).

[0032] In one embodiment, the epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol C epoxy resin and bisphenol fluorene epoxy resin.

[0033] In one embodiment, the organic phosphine-modified unsaturated polyester is a product generated by an addition reaction between an unsaturated polyester in a solvent and diphenylphosphine.

[0034] In one embodiment, in an inert atmosphere, the unsaturated polyester in a solvent is reacted with diphenylphosphine at 50-90° C. After the reaction, the solvent is removed, and the organic phosphine-modified unsaturated polyester is obtained through precipitation and drying.

[0035] In one embodiment, the molar ratio of the double bond groups of the unsaturated polyester to the phosphine groups of the diphenylphosphine is 1:(1.2-1.5).

[0036] In one embodiment, the solvent is one or more of chloroform, tetrahydrofuran, dimethyltetrahydrofuran, and N,N-dimethylformamide.

[0037] In one embodiment, the unsaturated polyester is obtained by the following process:

[0038] In an inert atmosphere, unsaturated acid or anhydride, dicarboxylic acid or anhydride, and diol are reacted at 140-180° C. in the presence of an esterification catalyst and a polymerization inhibitor; and then polycondensation is carried out at 140-180° C. and 0.05-0.09 MPa in the presence of a polycondensation catalyst.

[0039] In one embodiment, the unsaturated acid or anhydride is itaconic acid or itaconic anhydride.

[0040] Bio-based unsaturated polyester resins are sustainable resources, and most are biodegradable and biocompatible. The main raw materials for bio-based unsaturated polyester resins are itaconic acid, isosorbide, furan compounds, and vegetable oils. Itaconic acid, also known as methylenesuccinic acid, contains a carbon-carbon double bond and two carboxyl groups in its molecular structure, making it very similar to maleic acid. Itaconic acid can replace maleic acid or maleic anhydride by condensing with diols to form bio-based unsaturated polyester resins. Currently, itaconic acid is primarily produced using agricultural byproducts such as distiller's grains, starch, sugar beets, sugarcane, and straw. It is widely used in the synthesis of bio-based unsaturated polyester resins through large-scale fermentation using suitable fermentation strains (such as Candida albicans, Aspergillus itachius, and Aspergillus terreus).

[0041] In one embodiment, the dicarboxylic acid or anhydride is oxalic acid, succinic acid, adipic acid, sebacic acid, phthalic acid, phthalic acid, phthalic anhydride, isophthalic acid, diphenyl dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, chlorobridged anhydride, or bromobridged anhydride.

[0042] In one embodiment, the diol is 1,2-propylene glycol, 1,3-propylene glycol, ethylene glycol, 1,4-butanediol, pentanediol, 1,6-hexanediol, cyclohexanediol, dihexanediol, diethylene glycol, methylpropylene glycol, 3-chloropropylene glycol, 4-chloro-1,3-butanediol, dibromoneopentyl glycol, 2,3-dibromopropanol, 4-bromo-1,2-butanediol, or dibromobutenediol.

[0043] In one embodiment, the esterification catalyst is one or more of p-toluenesulfonic acid, manganese acetate, stannous chloride, dibutyltin oxide, stannous oxalate, zinc acetate, cobalt acetate, and titanium butoxide.

[0044] In one embodiment, the polymerization inhibitor is one or more of hydroquinone, trimethyl hydroquinone, p-tert-butylcatechol, tert-butyl hydroquinone, toluene hydroquinone, p-benzoquinone, naphthoquinone, hydroquinone monomethyl ether, phenothiazine, copper naphthenate, and copper chloride.

[0045] In one embodiment, the polycondensation catalyst is one or more of dibutyltin dilaurate, antimony trioxide, antimony acetate, antimony glycolate, titanium dioxide, tetraisopropyl titanate, tetra-n-butyl titanate, titanium glycolate, tetraphenyl titanate, titanium acetylacetonate, germanium dioxide, stannous oxalate, dibutyltin oxide, stannous octoate, tin acetylacetonate, aluminum phosphate, aluminum sulfate, aluminum nitrate, and aluminum chloride.

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present invention, rather than to represent all embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0047] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0048] Example 1:

[0049] Itaconic acid (33.64 mmol), phthalic anhydride (33.64 mmol), and 1,3-propylene glycol (67.28 mmol) were placed in a four-necked flask. p-Toluenesulfonic acid (1%) and hydroquinone (0.02%) were added. Connected to a water separator, stirrer, and thermometer, the flask was incubated at 180°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Dibutyltin dilaurate (1%) was added, the pressure was reduced to 0.05 MPa, and the polycondensation reaction was continued at 180°C for 3 hours to produce an unsaturated polyester. Figure 1 The H NMR spectrum of the unsaturated polyester is shown.

[0050] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in dimethyltetrahydrofuran (10 ml). Diphenylphosphine (11.37 mmol) was added and the mixture was stirred at 90°C for 8 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying. Figure 2 The hydrogen nuclear magnetic resonance spectrum of the organic phosphine-modified unsaturated polyester is shown.

[0051] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and an epoxy resin E51 (containing 2.521 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 120°C for 1 hour to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin. Figure 3a Shows a photo of the cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin.

[0052] Example 2:

[0053] Itaconic acid (33.64 mmol), phthalic anhydride (33.64 mmol), and 1,2-propylene glycol (67.28 mmol) were placed in a four-necked flask. p-Toluenesulfonic acid (0.5%) and hydroquinone (0.01%) were added. Connected to a water separator, stirrer, and thermometer, the flask was incubated at 140°C under a nitrogen atmosphere for 3 hours until no more water was produced in the water separator. The esterification reaction was completed. Dibutyltin dilaurate (0.5%) was added, the pressure was reduced to 0.09 MPa, and the polycondensation reaction was continued at 140°C for 5 hours to produce an unsaturated polyester.

[0054] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in tetrahydrofuran (10 ml). Diphenylphosphine (9.092 mmol) was added and stirred at 50°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0055] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and an epoxy resin E51 (containing 1.681 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 30°C for 24 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin. Figure 3b Shows a photo of the cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin.

[0056] Example 3:

[0057] Itaconic acid (33.64 mmol), terephthalic anhydride (33.64 mmol), and 1,4-butanediol (67.28 mmol) were placed in a four-necked flask. Manganese acetate (0.5%) and trimethylhydroquinone (0.01%) were added. Connected to a water separator, a stirrer, and a thermometer, the flask was incubated at 160°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Antimony trioxide (1%) was added, the pressure was reduced to 0.05 MPa, and polycondensation was carried out at 160°C for 4 hours to produce an unsaturated polyester.

[0058] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in tetrahydrofuran (10 ml). Diphenylphosphine (11.37 mmol) was added and stirred at 60°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0059] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and an epoxy resin E35 (containing 1.681 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 80°C for 4 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0060] Example 4:

[0061] Itaconic acid (33.64 mmol), isophthalic acid (33.64 mmol), and pentanediol (67.28 mmol) were placed in a four-necked flask. Stannous chloride (0.5%) and trimethylhydroquinone (0.01%) were added. Connected to a water separator, a stirrer, and a thermometer, the flask was incubated at 160°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Titanium dioxide (1%) was added, the pressure was reduced to 0.05 MPa, and the polycondensation reaction was continued at 160°C for 4 hours to produce an unsaturated polyester.

[0062] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in tetrahydrofuran (10 ml). Diphenylphosphine (11.37 mmol) was added and stirred at 60°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0063] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and an epoxy resin E44 (containing 1.681 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 80°C for 4 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0064] Example 5:

[0065] Itaconic acid (33.64 mmol), adipic acid (33.64 mmol), and 1,6-hexanediol (67.28 mmol) were placed in a four-necked flask. Dibutyltin oxide (0.5%) and p-tert-butylcatechol (0.01%) were added. Connected to a water separator, a stirrer, and a thermometer, the flask was incubated at 160°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Ethylene glycol antimony (1%) was added, the pressure was reduced to 0.05 MPa, and the polycondensation reaction was continued at 160°C for 4 hours to produce an unsaturated polyester.

[0066] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in dimethyltetrahydrofuran (10 ml). Diphenylphosphine (11.37 mmol) was added and the mixture was stirred at 60°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0067] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and an epoxy resin E44 (containing 1.681 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 80°C for 4 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0068] Example 6:

[0069] Itaconic acid (33.64 mmol), sebacic acid (33.64 mmol), and methylpropylene glycol (67.28 mmol) were placed in a four-necked flask. Stannous oxalate (0.5%) and p-toluene hydroquinone (0.01%) were added. Connected to a water separator, a stirrer, and a thermometer, the flask was heated at 160°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Titanium acetylacetonate (1%) was added, the pressure was reduced to 0.05 MPa, and the polycondensation reaction was continued at 160°C for 4 hours to produce an unsaturated polyester.

[0070] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in dimethyltetrahydrofuran (10 ml). Diphenylphosphine (11.37 mmol) was added and the mixture was stirred at 60°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0071] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and a bisphenol S epoxy resin (containing 1.891 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 100°C for 3 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0072] Example 7:

[0073] Itaconic acid (33.64 mmol), 2,6-naphthalenedicarboxylic acid (33.64 mmol), and 3-chloropropylene glycol (67.28 mmol) were placed in a four-necked flask. Titanium butoxide (0.5%) and p-benzoquinone (0.01%) were added. Connected to a water separator, a stirrer, and a thermometer, the flask was incubated at 160°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Stannous oxalate (1%) was added, the pressure was reduced to 0.05 MPa, and the polycondensation reaction was continued at 160°C for 4 hours to produce an unsaturated polyester.

[0074] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in dimethyltetrahydrofuran (10 ml). Diphenylphosphine (11.37 mmol) was added and the mixture was stirred at 60°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0075] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and a bisphenol S epoxy resin (containing 1.891 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 100°C for 3 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0076] Example 8:

[0077] Itaconic acid (33.64 mmol), chlorohydride (33.64 mmol), and 4-chloro-1,3-butanediol (67.28 mmol) were placed in a four-necked flask. Cobalt acetate (0.5%) and naphthoquinone (0.01%) were added. Connected to a water separator, a stirrer, and a thermometer, the flask was incubated at 160°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Dibutyltin oxide (1%) was added, the pressure was reduced to 0.05 MPa, and the polycondensation reaction was continued at 160°C for 4 hours to produce an unsaturated polyester.

[0078] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in chloroform (10 ml). Diphenylphosphine (11.37 mmol) was added and stirred at 60°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0079] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and a bisphenol F epoxy resin (containing 1.891 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 100°C for 3 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0080] Example 9:

[0081] Itaconic acid (33.64 mmol), chloroacetic anhydride (33.64 mmol), and dibromobutenediol (67.28 mmol) were placed in a four-necked flask. Zinc acetate (0.5%) and tert-butylhydroquinone (0.01%) were added. Connected to a water separator, a stirrer, and a thermometer, the flask was incubated at 160°C under a nitrogen atmosphere for 2 hours until no more water was produced in the water separator. The esterification reaction was completed. Tetraphenyl titanate (1%) was added, the pressure was reduced to 0.05 MPa, and the polycondensation reaction was continued at 160°C for 4 hours to produce an unsaturated polyester.

[0082] Under a nitrogen atmosphere, an unsaturated polyester (7.577 mmol of double bonds) was dissolved in chloroform (10 ml). Diphenylphosphine (11.37 mmol) was added and the mixture was stirred at 60°C for 24 hours until the reaction was complete. After the reaction, the solvent was removed, and the organic phosphine-modified unsaturated polyester was obtained by precipitation and drying.

[0083] An organic phosphine-modified unsaturated polyester (containing 2.101 mmol of phosphine groups) and a bisphenol F epoxy resin (containing 1.891 mmol of epoxy groups) were mixed evenly and poured into a mold. The mixture was cured at 80°C for 4 hours to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin.

[0084] Flame retardant performance test

[0085] In order to verify the flame retardant properties, the cured products of the organic phosphine-modified unsaturated polyester and epoxy resin prepared in Examples 1-9 were tested according to the vertical burning test in the American standard UL94 flame retardant grade test standard.

[0086] Table 1

[0087]

[0088] Note: Definition of V-0 level: When the material is exposed to a flame for 10 seconds twice, and the burning time each time does not exceed 10 seconds, the total burning time does not exceed 50 seconds, and there is no dripping of burning materials during the test or the dripping materials cannot ignite the absorbent cotton.

[0089] From the test results in Table 1, it can be seen that the UL-94 test results of the cured products of the organic phosphine-modified unsaturated polyester and epoxy resin prepared in Examples 1-9 are all V-0.

[0090] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application shall be included in the scope of protection of this application.

Claims

1. A cured product of an organic phosphine-modified unsaturated polyester and an epoxy resin, characterized in that: The solidified material is a cross-linked polymer of an organic phosphine-modified unsaturated polyester and an epoxy resin; The organic phosphine-modified unsaturated polyester is a product generated by an addition reaction between an unsaturated polyester in a solvent and diphenylphosphine; The solvent is one or more of chloroform, dimethyltetrahydrofuran, and N,N-dimethylformamide; The unsaturated polyester is obtained by reacting an unsaturated acid or anhydride, a dicarboxylic acid or anhydride, and a diol at 140-180° C. in the presence of an esterification catalyst and a polymerization inhibitor in an inert atmosphere; and then performing a polycondensation reaction at 140-180° C. and 0.05-0.09 MPa in the presence of a polycondensation catalyst; The unsaturated acid or anhydride is itaconic acid or itaconic anhydride; The dicarboxylic acid or anhydride is oxalic acid, succinic acid, adipic acid, sebacic acid, phthalic acid, phthalic anhydride, isophthalic acid, biphenyl dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, chlorobridged anhydride or bromobridged anhydride; The diol is 1,2-propylene glycol, 1,3-propylene glycol, ethylene glycol, 1,4-butanediol, pentanediol, 1,6-hexanediol, cyclohexanediol, dihexanediol, diethylene glycol, methylpropylene glycol, chloropropylene glycol, 4-chloro-1,3-butanediol, dibromoneopentyl glycol, 2,3-dibromopropanol, 4-bromo-1,2-butanediol or dibromobutylene glycol.

2. The cured product according to claim 1, wherein The molar ratio of the phosphine group of the organic phosphine-modified unsaturated polyester to the epoxy group of the epoxy resin is 1:(0.8-1.2).

3. The cured product according to claim 1 or 2, characterized in that The epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol C epoxy resin and bisphenol fluorene epoxy resin.

4. A method for preparing a cured product of an organophosphine-modified unsaturated polyester and an epoxy resin, comprising: Mixing an organic phosphine-modified unsaturated polyester with an epoxy resin and curing the mixture to obtain a cured product of the organic phosphine-modified unsaturated polyester and the epoxy resin; The organic phosphine-modified unsaturated polyester is a product generated by an addition reaction between an unsaturated polyester in a solvent and diphenylphosphine; The solvent is one or more of chloroform, dimethyltetrahydrofuran, and N,N-dimethylformamide; The unsaturated polyester is obtained by reacting an unsaturated acid or anhydride, a dicarboxylic acid or anhydride, and a diol at 140-180° C. in the presence of an esterification catalyst and a polymerization inhibitor in an inert atmosphere; and then performing a polycondensation reaction at 140-180° C. and 0.05-0.09 MPa in the presence of a polycondensation catalyst; The unsaturated acid or anhydride is itaconic acid or itaconic anhydride; The dicarboxylic acid or anhydride is oxalic acid, succinic acid, adipic acid, sebacic acid, phthalic acid, phthalic anhydride, isophthalic acid, biphenyl dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, chlorobridged anhydride or bromobridged anhydride; The diol is 1,2-propylene glycol, 1,3-propylene glycol, ethylene glycol, 1,4-butanediol, pentanediol, 1,6-hexanediol, cyclohexanediol, dihexanediol, diethylene glycol, methylpropylene glycol, chloropropylene glycol, 4-chloro-1,3-butanediol, dibromoneopentyl glycol, 2,3-dibromopropanol, 4-bromo-1,2-butanediol or dibromobutylene glycol.

5. The method according to claim 4, characterized in that The molar ratio of the phosphine group of the organic phosphine-modified unsaturated polyester to the epoxy group of the epoxy resin is 1:(0.8-1.2).

6. The method according to claim 4, characterized in that The epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol C epoxy resin and bisphenol fluorene epoxy resin.

7. The method according to claim 6, characterized in that The molar ratio of the double bond groups of the unsaturated polyester to the phosphine groups of the diphenylphosphine is 1:(1.2-1.5).

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