Spiro phosphate as well as preparation method and application thereof

Abstract

The invention discloses spirocyclic phosphate as well as a preparation method and application thereof. The structural formula of the spirocyclic phosphate is # imgabs0. The preparation method of the spirocyclic phosphate comprises the following steps: (1) carrying out reaction on furfuryl amine and vanillin to obtain a Schiff base intermediate; 2) carrying out a reaction between the Schiff base intermediate and pentaerythritol diphosphate diphosphoryl chloride to obtain a flame retardant precursor; and (3) carrying out a reaction on the flame retardant precursor and the 9, 10-dihydro-9 oxa-10 phosphaphenanthrene-10-oxide, so as to obtain the spiro phosphate. The spirocyclic phosphate serving as the epoxy resin flame retardant has the advantages of excellent flame retardance, good smoke suppression effect, good thermal stability, good compatibility with epoxy resin, environmental friendliness and the like, and the preparation method is simple, wide in raw material source, low in production cost and suitable for large-scale industrial production and application.

Description

Technical Field

[0001] The invention relates to the technical field of flame retardant materials, and in particular to a spirocyclic phosphate and a preparation method and application thereof. Background Art

[0002] Epoxy resin is a widely used resin, but due to the poor flame retardancy of epoxy resin, flame retardants need to be added to improve its flame retardant properties. At present, flame retardants used for epoxy resin can be divided into halogen flame retardants, inorganic flame retardants and phosphorus-nitrogen flame retardants. Halogen flame retardants have high flame retardant efficiency, but they cause great pollution to the environment and their applications are greatly restricted. The flame retardant effect of inorganic flame retardants is usually not as good as that of organic flame retardants, and a large amount of addition is required to achieve the expected flame retardant effect. The large amount of inorganic flame retardants added will affect the mechanical strength and processing properties of the material, and will also cause the fluidity of the material to deteriorate, affecting the processing and product performance of the material. Phosphorus-nitrogen flame retardants do not contain halogen atoms and have high flame retardant efficiency. They are currently a research hotspot in the field of flame retardants. However, the flame retardant properties of existing phosphorus-nitrogen flame retardants need to be further improved, and they are not green and environmentally friendly enough, making it difficult to fully meet the growing practical application requirements.

[0003] Therefore, it is of great significance to develop a flame retardant with excellent flame retardant properties, good smoke suppression effect, and green environmental protection. Summary of the invention

[0004] The purpose of the present invention is to provide a spirocyclic phosphate and a preparation method and application thereof.

[0005] The technical solution adopted by the present invention is:

[0006] A spirocyclic phosphate, the structural formula of which is as follows:

[0007]

[0008] A method for preparing the spirocyclic phosphate as described above comprises the following steps:

[0009] 1) reacting furfurylamine and vanillin to obtain

[0010] 2) Conduct and pentaerythritol bisphosphate diphosphoryl chloride to obtain

[0011]

[0012] 3) Conduct The spirocyclic phosphate is obtained by reacting with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0013] Preferably, a method for preparing the spirocyclic phosphate as described above comprises the following steps:

[0014] 1) Dispersing furfurylamine and vanillin in a solvent for reaction, and then separating and purifying the product to obtain

[0015]

[0016] 2) Pentaerythritol bisphosphate diphosphoryl chloride and an acid binding agent are dispersed in a solvent for reaction, and then the product is separated and purified to obtain

[0017]

[0018] 3) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are dispersed in a solvent for reaction, and then the product is separated and purified to obtain the spirocyclic phosphate.

[0019] Preferably, in step 1), the molar ratio of furfurylamine to vanillin is 1:1.0-1.2.

[0020] Preferably, the solvent in step 1) is at least one of ethanol, methanol, dimethylformamide and 1,2-dichloroethane.

[0021] Preferably, the reaction in step 1) is carried out at a temperature of 50° C. to 80° C., and the reaction time is 6 h to 10 h.

[0022] Preferably, step 2) The molar ratio of pentaerythritol bisphosphate to diphosphoryl chloride is 2.0-2.2:1.

[0023] Preferably, in step 2), the molar ratio of pentaerythritol bisphosphate diphosphoryl chloride to the acid binding agent is 1:2.5-3.0.

[0024] Preferably, the acid binding agent in step 2) is at least one of triethylamine, pyridine, N,N-diisopropylethylamine, potassium carbonate and sodium carbonate.

[0025] Preferably, the solvent in step 2) is at least one of acetonitrile, 1,4-dioxane, and 1,2-dichloroethane.

[0026] Preferably, the reaction in step 2) is carried out at a temperature of 70°C to 90°C, and the reaction time is 12h to 16h.

[0027] Preferably, the reaction in step 2) is carried out in a protective atmosphere.

[0028] Preferably, the protective atmosphere is a nitrogen atmosphere or an argon atmosphere.

[0029] Preferably, step 3) The molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is 1:2.0-2.5.

[0030] Preferably, the solvent in step 3) is at least one of ethanol, 1,4-dioxane, dimethylformamide, 1,2-dichloroethane and chloroform.

[0031] Preferably, the reaction in step 3) is carried out at a temperature of 60°C to 90°C, and the reaction time is 12h to 16h.

[0032] A flame retardant comprising the above spirocyclic phosphate.

[0033] An epoxy resin composite material comprises the spirocyclic phosphate ester.

[0034] Preferably, the mass percentage of the spirocyclic phosphate in the epoxy resin composite material is 5% to 15%.

[0035] The beneficial effects of the present invention are as follows: the spirocyclic phosphate of the present invention is used as an epoxy resin flame retardant and has the advantages of excellent flame retardancy, good smoke suppression effect, good thermal stability, good compatibility with epoxy resin, and green environmental protection. In addition, the preparation method is simple, the raw material source is wide, the production cost is low, and it is suitable for large-scale industrial production and application.

[0036] Specifically:

[0037] 1) The spirocyclic phosphate of the present invention has excellent flame retardant properties when used as an epoxy resin flame retardant (when used for epoxy resin, the addition amount is 7.5wt% to 15wt%, the LOI can reach 30.0% to 31.1%, and the UL-94 flame retardant grade can reach V-0), and has excellent charring performance and good smoke suppression effect;

[0038] 2) The spirocyclic phosphate of the present invention has good thermal stability, good compatibility with epoxy resin, is green and environmentally friendly, and is suitable for flame retardant epoxy resin;

[0039] 3) The spirocyclic phosphate of the present invention is prepared with furfurylamine and vanillin as main raw materials, the raw materials are widely available, and the preparation method is simple and the production cost is low, so the spirocyclic phosphate is suitable for large-scale industrial production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is the hydrogen nuclear magnetic resonance spectrum of the spirocyclic phosphate in Example 1.

[0041] Figure 2 It is the mass spectrum of the spirocyclic phosphate in Example 1.

[0042] Figure 3The thermogravimetric curve and the derivative thermogravimetric curve of the spirocyclic phosphate in Example 1 in a nitrogen atmosphere.

[0043] Figure 4 This is a comparison chart of the total smoke release of the epoxy resin composite material in Example 3 and the E44 epoxy resin after cone calorimetry testing.

[0044] Figure 5 This is a comparison chart of the carbonization effects of the epoxy resin composite material in Example 3 and the E44 epoxy resin after cone calorimetry testing. DETAILED DESCRIPTION

[0045] The present invention will be further explained and illustrated below in conjunction with specific embodiments.

[0046] Embodiment 1:

[0047] A spirocyclic phosphate, the preparation method of which is as follows:

[0048] 1) Add 9.7 g (0.1 mol) of furfurylamine and 15.2 g (0.1 mol) of vanillin to 100 mL of ethanol, heat to 60 ° C and stir for 6 h, let stand and cool naturally to room temperature to wait for solid precipitation, filter, take the solid and wash it with ice ethanol 3 times to obtain Schiff base intermediate (yield 92.0%);

[0049] The reaction that occurs in this step is as follows:

[0050]

[0051] 2) 18.5 g (0.08 mol) of 11.9 g (0.04 mol) of pentaerythritol bisphosphate diphosphoryl chloride and 14 mL (0.1 mol) of triethylamine were added to 120 mL of acetonitrile, nitrogen was filled for protection, and the temperature was raised to 80 ° C for reaction for 12 h, and then the acetonitrile was removed by rotary evaporation, and the solid was dissolved with 50 mL of chloroform, and then washed with water for 3 times, and then the chloroform was removed by rotary evaporation to obtain a flame retardant precursor. (yield 88.0%);

[0052] The reaction that occurs in this step is as follows:

[0053]

[0054] 3) 13.6 g (0.02 mol) of and 8.6 g (0.04 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide were added to 100 mL of 1,4-dioxane, the temperature was raised to 60°C for reaction for 16 h, and then 1,4-dioxane was removed by rotary evaporation, and then extracted with chloroform and water system, the volume ratio of chloroform to water was 2:1, and then the chloroform layer was rotary evaporated to remove chloroform, and then washed with ice ethanol for 3 times, and then vacuum dried at 70°C for 16 h to obtain spirocyclic phosphate (light yellow solid, recorded as FSPC; yield was 82.3%);

[0055] The reaction that occurs in this step is as follows:

[0056]

[0057] Note:

[0058] The preparation method of pentaerythritol bisphosphate diphosphoryl chloride in this embodiment is as follows:

[0059] 13.6 g of pentaerythritol and 122 mg of 4-dimethylaminopyridine were added to 100 mL of chlorobenzene, and nitrogen was filled for protection. Then 28.5 mL of phosphorus oxychloride was slowly added. After the addition was completed, the reaction was carried out for 2 hours, and then the temperature was raised to 110° C. and the reaction was carried out overnight until no hydrogen chloride gas was generated in the system. Then, the reaction was naturally cooled to room temperature, filtered, and the solid was washed with dichloromethane 3 times, and then vacuum dried at 70° C. for 12 hours to obtain pentaerythritol bisphosphate diphosphoryl chloride (white solid, denoted as SPDPC; the yield was 81.2%).

[0060] The NMR data of pentaerythritol bisphosphate diphosphoryl chloride (SPDPC) are as follows:

[0061] 1 H NMR (400MHz, DMSO): δ4.26 (s, 4H), 4.23 (s, 4H);

[0062] 13 C NMR (400MHz, DMSO): δ70.38(s), 36.39(s);

[0063] 31 P NMR (400MHz, DMSO): δ7.32(s).

[0064] The nuclear magnetic resonance hydrogen spectrum of the spirocyclic phosphate (FSPC) in this example is as follows Figure 1 As shown in the mass spectrum Figure 2 As shown, the thermogravimetric curve and differential thermogravimetric curve in nitrogen atmosphere are as follows Figure 3 shown.

[0065] Depend on Figure 1It can be seen that: c and f are the corresponding hydrogens on all benzene rings in the spirocyclic phosphate structure, g is the corresponding hydrogen on the furan ring, a is the methyl peak corresponding to vanillin, and d is the methylene peak at the benzyl position of the furan ring, indicating that a spirocyclic phosphate with the expected structure was indeed synthesized in this embodiment.

[0066] Depend on Figure 2 It can be seen that the mass-to-charge ratio of the peak with the highest abundance is 1119, and the mass of the electron minus the impact of mass spectrometry detection is 1118, which is consistent with the relative molecular mass of the target flame retardant spirocyclic phosphate.

[0067] Depend on Figure 3 It can be seen that the spirocyclic phosphate begins to decompose rapidly when heated to about 200°C, and about 40% of it remains in the end.

[0068] An epoxy resin composite material, the preparation method of which is as follows:

[0069] 5 parts by mass of the above-mentioned spirocyclic phosphate were dissolved in 4 parts by mass of chloroform, and then added to 100 parts by mass of E44 epoxy resin, heated to 100°C and stirred for 20 minutes, then cooled to 90°C and added with 25 parts by mass of 4,4-diaminodiphenylmethane (DDM), and stirred for 5 minutes. After degassing for 3 minutes using an oil pump, the mixture was immediately poured into a polytetrafluoroethylene mold preheated to 110°C, and then cured at 110°C for 2 hours, and then cured at 150°C for 2 hours to obtain an epoxy resin composite material (denoted as EP / 5% FSPC).

[0070] According to tests, the limiting oxygen index (LOI) of the epoxy resin composite material (EP / 5% FSPC) in this embodiment is 29.0%, and the UL-94 flame retardant grade is V-1.

[0071] Note:

[0072] Limiting oxygen index: measured on a VOUCH 5801A oxygen index instrument with reference to "ASTM D2863: Plastic minimum oxygen concentration test", the size of the test specimen is 130mm×10mm×4mm.

[0073] UL-94 flame retardant grade: measured with reference to UL-94 standard using VOUCH 5420 horizontal vertical combustion instrument, the size of the test specimen is 130mm×13mm×4mm.

[0074] Embodiment 2:

[0075] An epoxy resin composite material, the preparation method of which is as follows:

[0076] 7.5 parts by mass of the spirocyclic phosphate in Example 1 was dissolved in 6 parts by mass of chloroform, and then added to 100 parts by mass of E44 epoxy resin, heated to 100°C and stirred for 20 minutes, then cooled to 90°C and added with 25 parts by mass of 4,4-diaminodiphenylmethane (DDM), and stirred for 5 minutes. After degassing for 3 minutes using an oil pump, the mixture was immediately poured into a polytetrafluoroethylene mold preheated to 110°C, and then cured at 110°C for 2 hours, and then cured at 150°C for 2 hours to obtain an epoxy resin composite material (denoted as EP / 7.5% FSPC).

[0077] According to tests, the limiting oxygen index (LOI) of the epoxy resin composite material (EP / 7.5% FSPC) in this embodiment is 30.2%, and the UL-94 flame retardant grade is V-1.

[0078] Embodiment 3:

[0079] An epoxy resin composite material, the preparation method of which is as follows:

[0080] 10 parts by mass of the spirocyclic phosphate in Example 1 was dissolved in 8 parts by mass of chloroform, and then added to 100 parts by mass of E44 epoxy resin, heated to 100°C and stirred for 20 minutes, then cooled to 90°C and added with 25 parts by mass of 4,4-diaminodiphenylmethane (DDM), and continued to stir for 5 minutes. After degassing for 3 minutes using an oil pump, the mixture was immediately poured into a polytetrafluoroethylene mold preheated to 110°C, and then cured at 110°C for 2 hours, and then cured at 150°C for 2 hours to obtain an epoxy resin composite material (denoted as EP / 10% FSPC).

[0081] According to tests, the limiting oxygen index (LOI) of the epoxy resin composite material (EP / 10% FSPC) in this embodiment is 31.1%, and the UL-94 flame retardant grade is V-0.

[0082] The total smoke release of the epoxy resin composite material (EP / 10% FSPC) and E44 epoxy resin (denoted as EP) after cone calorimetry testing is compared as shown in the figure below: Figure 4 As shown in the figure, the carbonization effect comparison is as follows Figure 5 (a is EP; b is EP / 10% FSPC).

[0083] Depend on Figure 4 It can be seen that after adding FSPC, the total smoke release of epoxy resin combustion decreased by about 22%, indicating that FSPC has a good smoke suppression effect.

[0084] Depend on Figure 5 It can be seen that after adding FSPC, the amount of charring during the combustion of epoxy resin increased significantly, indicating that FSPC can effectively promote charring.

[0085] Embodiment 4:

[0086] A spirocyclic phosphate, the preparation method of which is as follows:

[0087] 1) Add 9.7 g (0.1 mol) of furfurylamine and 15.2 g (0.1 mol) of vanillin to 100 mL of methanol, heat to 50 ° C and stir for 8 h, let stand and cool naturally to room temperature to wait for solid precipitation, filter, take the solid and wash it with ice ethanol 3 times to obtain Schiff base intermediate (yield 91.2%);

[0088] 2) 18.5 g (0.08 mol) of 11.9 g (0.04 mol) of pentaerythritol bisphosphate diphosphoryl chloride (same as in Example 1) and 15 mL (0.09 mol) of N,N-diisopropylethylamine were added to 120 mL of 1,4-dioxane, nitrogen was filled for protection, and the temperature was raised to 80 ° C for reaction for 12 h, and then 1,4-dioxane was removed by rotary evaporation, and the solid was dissolved in 50 mL of chloroform, washed with water 3 times, and then chloroform was removed by rotary evaporation to obtain a flame retardant precursor. (yield 86.5%);

[0089] 3) 13.6 g (0.02 mol) of 8.6 g (0.04 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added to 100 mL of ethanol, the temperature was raised to 90 ° C for reaction for 16 h, and then the ethanol was removed by rotary evaporation, and then extracted with chloroform and water system, the volume ratio of chloroform to water was 2:1, and the chloroform layer was rotary evaporated to remove chloroform, and then washed with ice ethanol for 3 times, and then vacuum dried at 70 ° C for 16 h to obtain spirocyclic phosphate (light yellow solid, recorded as FSPC; yield was 79.0%).

[0090] An epoxy resin composite material, the preparation method of which is as follows:

[0091] 5 parts by mass of the above-mentioned spirocyclic phosphate were dissolved in 4 parts by mass of chloroform, and then added to 100 parts by mass of E44 epoxy resin, heated to 100°C and stirred for 25 minutes, then cooled to 90°C and added with 25 parts by mass of 4,4-diaminodiphenylmethane (DDM), and stirred for 5 minutes. After degassing for 3 minutes using an oil pump, the mixture was immediately poured into a polytetrafluoroethylene mold preheated to 110°C, and then cured at 110°C for 2 hours, and then cured at 150°C for 2 hours to obtain an epoxy resin composite material (denoted as EP / 5% FSPC).

[0092] According to tests, the limiting oxygen index (LOI) of the epoxy resin composite material (EP / 5% FSPC) in this embodiment is 29.2%, and the UL-94 flame retardant grade is V-1.

[0093] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A spirocyclic phosphate, characterized in that The structural formula is as follows:

2. A method for preparing a spirocyclic phosphate as claimed in claim 1, characterized in that: The following steps are involved: 1) reacting furfurylamine and vanillin to obtain 2) Conduct and pentaerythritol bisphosphate diphosphoryl chloride to obtain 3) Conduct The spirocyclic phosphate is obtained by reacting with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

3. The preparation method according to claim 2, characterized in that: In step 1), the molar ratio of furfurylamine to vanillin is 1:1.0-1.

2.

4. The preparation method according to claim 2 or 3, characterized in that: Step 1) The reaction is carried out at a temperature of 50°C to 80°C and the reaction time is 6h to 10h.

5. The preparation method according to claim 2, characterized in that: Step 2) The molar ratio of pentaerythritol bisphosphate to diphosphoryl chloride is 2.0-2.2:

1.

6. The preparation method according to claim 2 or 5, characterized in that: Step 2) The reaction is carried out at a temperature of 70°C to 90°C and the reaction time is 12h to 16h.

7. The preparation method according to claim 2, characterized in that: Step 3) The molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:2.0-2.

5.

8. The preparation method according to claim 2 or 7, characterized in that: Step 3) The reaction is carried out at a temperature of 60°C to 90°C and the reaction time is 12h to 16h.

9. A flame retardant, characterized in that: Contains the spirocyclic phosphate described in claim 1.

10. An epoxy resin composite material, characterized in that: Contains the spirocyclic phosphate described in claim 1.

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