A multi-valence state phosphorus-containing modifier, a preparation method and application thereof

Abstract

The present application relates to the technical field of flame-retardant modifier, in particular to a multi-valence phosphorus-containing modifier, a preparation method and application thereof, the preparation method comprises the following steps: S1, mixing a phosphorus-containing acidic compound with a phosphorus-containing hydroxyl compound, and performing a phosphate esterification reaction to obtain a phosphate esterification product; S2, mixing the phosphate esterification product with a solvent, and then adding a nitrogen-containing compound to perform a salting reaction, thereby obtaining the multi-valence phosphorus-containing modifier; the valence states of phosphorus elements in the phosphorus-containing acidic compound and the phosphorus-containing hydroxyl compound are different. The present application adopts a plurality of valence phosphorus-containing compounds, and the different valence phosphorus-containing compounds have different flame-retardant mechanisms. Integrating phosphorus elements with different valence states into the same molecular structure realizes the synergistic effect of gas-phase and condensed-phase flame retardation, significantly improves the flame-retardant efficiency, solves the migration problem of traditional flame retardants, and overcomes the defect of low flame-retardant efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flame retardant modifier, in particular to a multi-valence phosphorus-containing modifier and a preparation method and application thereof. BACKGROUND

[0002] The migration of flame retardants is a key factor affecting the long-term use performance of polymer materials. In polymer systems such as polyesters, polyamides, and epoxy resins, small molecule flame retardants are prone to precipitate from the matrix, not only leading to a decrease in flame retardant performance, but also possibly polluting the environment. Moreover, traditional flame retardants have the problem of low flame retardant efficiency, and it is difficult to simultaneously meet the requirements of high flame retardant performance and mechanical properties. SUMMARY

[0003] The purpose of the present application is to provide a multi-valence phosphorus-containing modifier and a preparation method and application thereof, in order to solve the defects of traditional flame retardants that cannot be used for a long time and have poor flame retardant efficiency and mechanical properties.

[0004] To achieve the above-mentioned purpose, the present application provides a preparation method of a multi-valence phosphorus-containing modifier, comprising the following preparation steps:

[0005] S1, mixing a phosphorus-containing acidic compound and a phosphorus-containing hydroxyl-containing compound, and performing a phosphoric acid esterification reaction to obtain a phosphoric acid esterification product;

[0006] S2, mixing the phosphoric acid esterification product with a solvent, adding a nitrogen-containing compound, and performing a salt reaction to obtain the multi-valence phosphorus-containing modifier;

[0007] The valence states of phosphorus elements in the phosphorus-containing acidic compound and the phosphorus-containing hydroxyl-containing compound are different.

[0008] In the present application, the phosphorus-containing acidic compound in S1 includes phytic acid, phosphoric acid, phenylphosphonic acid, (4-bromophenyl) phosphonic acid, or phenyl phosphite; and the phosphorus-containing hydroxyl-containing compound includes trimethylol phosphine oxide, 6- (1,3-dihydroxypropan-2-yl) oxy) dibenzo [c, e] [1,2] oxaphosphorin-6-oxide, 1,3-dihydroxypropan-2-yl diphenyl phosphinic acid ester, 1,3-dihydroxypropan-2-yl diphenyl phosphite, 6- ((bis (2-hydroxyethyl) amino) methyl) dibenzo [c, e] [1,2] oxaphosphorin-6-oxide, (bis (2-hydroxyethyl) amino) methyl) diphenyl phosphine oxide, and (bis (2-hydroxyethyl) amino) methyl) diphenyl phosphite.

[0009] In the present application, the phosphorus-containing hydroxyl-containing compound is preferably trimethylol phosphine oxide.

[0010] In the present application, the CAS number of phytic acid is 83-86-3, the CAS number of phenylphosphonic acid is 1571-33-1, the CAS number of (4-bromophenyl)phosphonic acid is 16839-13-7, the CAS number of phenyl phosphate is 701-64-4, and the CAS number of trimethyl phosphine oxide is 1067-12-5.

[0011] In the present application, the structural formula of 6-((bis(2-hydroxyethyl)amino)methyl)dibenzo[c,e][1,2]oxaphosphorin-6-oxide is:

[0012] .

[0013] In the present application, the structural formula of 1,3-dihydroxypropan-2-yl diphenylphosphinic acid ester is: .

[0014] In the present application, the structural formula of 1,3-dihydroxypropan-2-yl diphenyl phosphate is:

[0015] .

[0016] In the present application, the structural formula of 6-((bis(2-hydroxyethyl)amino)methyl)dibenzo[c,e][1,2]oxaphosphorin-6-oxide is:

[0017] .

[0018] In the present application, the structural formula of (bis(2-hydroxyethyl)amino)methyl)diphenyl phosphine oxide is:

[0019] .

[0020] In the present application, the structural formula of (bis(2-hydroxyethyl)amino)methyl)diphenyl phosphine oxide is:

[0021] .

[0022] In the present application, the molar ratio of the phosphorus-containing acidic compound to the phosphorus-containing hydroxyl-containing compound in S1 is 1:2-6.

[0023] In the present application, the temperature of the phosphonate esterification reaction in S1 is 120-180°C, and the time of the phosphonate esterification reaction is 2-10h.

[0024] In the present application, the solvent in S2 includes one or more of water, ethanol, tetrahydrofuran, dichloromethane, N,N-dimethylformamide, etc.; the molar volume ratio of the phosphorus-containing acidic compound to the solvent is 0.02 mol:30-100 mL.

[0025] In this invention, the CAS number of tetrahydrofuran is 109-99-9, the CAS number of dichloromethane is 75-09-2, and the CAS number of N,N-dimethylformamide is 68-12-2.

[0026] In this invention, the nitrogen-containing compound in S2 includes one or more of urea, 3,5-diamino-1,2,4-triazole, 2,2,6,6-tetramethylpiperidinamine, 2,4-diamino-6-hydroxypyrimidine, adipic acid dihydrazide, N-aminoethylpiperazine, 1-methanesulfonylpiperazine, melamine, and dicyandiamide.

[0027] In this invention, the CAS number of urea is 57-13-6, the CAS number of 3,5-diamino-1,2,4-triazole is 503-88-8, the CAS number of 2,2,6,6-tetramethylpiperidineamine is 36768-62-4, the CAS number of 2,4-diamino-6-hydroxypyrimidine is 56-06-4, the CAS number of adipic acid dihydrazide is 1071-93-8, the CAS number of N-aminoethylpiperazine is 140-31-8, the CAS number of 1-methanesulfonylpiperazine is 55276-43-2, the CAS number of melamine is 108-78-1, and the CAS number of dicyandiamide is 461-58-5.

[0028] In this invention, the molar ratio of nitrogen-containing compound to phosphoric acid-containing compound is 0.1-0.2:0.02.

[0029] In this invention, the temperature of the salt formation reaction in S2 is 20-120℃, and the time of the salt formation reaction is 3-10h.

[0030] The present invention also provides a multivalent phosphorus-containing modifier prepared by the above-described method for preparing multivalent phosphorus-containing modifiers.

[0031] The present invention also provides the application of the above-mentioned multivalent phosphorus-containing modifiers in flame retardants or surface modifiers.

[0032] This invention also provides a method for applying the above-mentioned multivalent phosphorus-containing modifier in flame retardants or surface modifiers, comprising the following steps:

[0033] A multivalent phosphorus-containing modifier is mixed with a solvent to obtain an impregnation solution. The fiber material is then immersed in the impregnation solution, dried, and the modified fiber material is obtained. The modified fiber material is then mixed with a resin and cured to obtain a fiber-reinforced polymer. The solvent includes one or more of the following: water, ethanol, tetrahydrofuran, dichloromethane, and N,N-dimethylformamide. The fiber material includes carbon fiber, glass fiber, basalt, ramie, and cotton fabric. The mass fraction of the multivalent phosphorus-containing modifier in the impregnation solution is 5%-30%, and the resin includes one of polyester, polyamide, and epoxy resin.

[0034] The present application has the following beneficial effects:

[0035] The present application provides a preparation method of a multi-valence phosphorus-containing modifier, S1, mixing a phosphorus-containing acidic compound and a phosphorus-containing hydroxyl-containing compound to perform a phosphate esterification reaction to obtain a phosphate esterification product; S2, mixing the phosphate esterification product with a solvent and adding a nitrogen-containing compound to perform a salting reaction, thereby obtaining the multi-valence phosphorus-containing modifier; the valence states of phosphorus in the phosphorus-containing acidic compound and the phosphorus-containing hydroxyl-containing compound are different. The present application limits the valence states of phosphorus in the phosphorus-containing acidic compound and the phosphorus-containing hydroxyl-containing compound in the reaction raw materials, constructs the multi-valence phosphorus-containing modifier with multi-valence phosphorus and intensive hydrogen bond groups, and realizes gas phase-coagulation phase synergistic flame retardation.

[0036] The present application further limits that the phosphorus-containing acidic compound in S1 includes phytic acid, phosphoric acid, phenylphosphonic acid, (4-bromophenyl) phosphonic acid or phenyl phosphite; the phosphorus-containing hydroxyl-containing compound includes trimethyl phosphine oxide, 6- (1,3-dihydroxypropan-2-yl) oxy) dibenzo [c, e] [1,2] oxaphosphorin-6-oxide, 1,3-dihydroxypropan-2-yl diphenyl phosphinate, 1,3-dihydroxypropan-2-yl diphenyl phosphite, 6- ((bis (2-hydroxyethyl) amino) methyl) dibenzo [c, e] [1,2] oxaphosphorin-6-oxide, (bis (2-hydroxyethyl) amino) methyl) diphenyl phosphine oxide, (bis (2-hydroxyethyl) amino) methyl) diphenyl phosphite. The valence state of phosphorus in the phosphorus-containing acidic compound includes positive trivalence and positive pentavalence, and the valence state of phosphorus in the phosphorus-containing hydroxyl-containing compound includes negative monovalence, positive monovalence and positive trivalence. Different valence phosphorus compounds have different flame retardant mechanisms. The positive pentavalence phosphorus mainly plays a coagulation phase flame retardant role by promoting carbonization. In the combustion process, a stable carbon layer can be formed on the surface of the material, which can block heat transfer and prevent the diffusion of oxygen and combustible gas, thereby inhibiting the continuous combustion of the material; the chemical activity of the positive trivalent phosphorus is between that of the positive pentavalence and the negative monovalence, and it has the dual effects of gas phase and coagulation phase flame retardation. In the combustion process, on the one hand, it participates in the formation of the carbon layer through moderate oxidation reaction, enhancing the heat insulation and oxygen insulation ability of the coagulation phase (similar to the carbonization auxiliary role of positive pentavalence); on the other hand, it decomposes to produce phosphorus-containing intermediates at high temperature, which can capture active free radicals (such as -OH, -H) in the gas phase, and assist in interrupting the combustion chain reaction (similar to the gas phase flame retardant logic of negative monovalence). This "two-way synergistic" feature can fill the gap between positive pentavalence (coagulation phase biased) and negative monovalence (gas phase biased), further improving the response speed and coverage of the overall flame retardant system;

[0037] The positive univalence phosphorus has strong reduction, and the oxidation reaction will occur preferentially in the low temperature stage of the initial combustion stage to release the phosphorus-containing flame retardant gas, thereby inhibiting the flame spreading in the gas phase in advance and playing the role of "early flame retardant". Meanwhile, the oxidation product can be converted into high valence state phosphorus (such as positive trivalence, positive pentavalence), which continuously participates in the subsequent condensed phase carbonization process and cooperates with other valence state phosphorus to prolong the flame retardant time and reduce the performance decay caused by the migration of the flame retardant; the negative univalence phosphorus tends to produce phosphorus-containing free radicals to play the flame retardant effect in the gas phase.

[0038] The application adopts the phosphorus-containing compounds with multiple valence states, and the phosphorus-containing compounds with different valence states have different flame retardant mechanisms. The phosphorus elements with different valence states are integrated into the same molecular structure to realize the synergistic effect of the gas phase and condensed phase flame retardant, thereby significantly improving the flame retardant efficiency.

[0039] The multi-valence state phosphorus-containing modifier prepared by the preparation method of the multi-valence state phosphorus-containing modifier provided by the application can inhibit the migration of the flame retardant through the hydrogen bond effect, thereby prolonging the service life of the flame retardant.

[0040] The application also provides the application of the multi-valence state phosphorus-containing modifier in the flame retardant or the surface modifier. When the multi-valence state phosphorus-containing modifier is used as the flame retardant or the surface modifier, the polar groups in the molecule can be combined with the fiber surface and the resin matrix at the same time through the hydrogen bond effect, thereby playing the role of "molecular bridge" and significantly improving the interfacial adhesion strength. In addition, the synergistic flame retardant effect of the multi-valence state phosphorus-containing modifier can promote the formation of a stable carbon layer in the interface region during the combustion, thereby effectively inhibiting the interface cracking. The migration problem of the traditional flame retardant is solved, and the defect of low flame retardant efficiency is overcome.

[0041] The technical solutions of the application will be further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is the flow chart of the preparation method of the multi-valence state phosphorus-containing modifier provided by the embodiment 1 of the application;

[0043] Figure 2 is the flow chart of the preparation method of the multi-valence state phosphorus-containing modifier provided by the embodiment 2 of the application;

[0044] Figure 3 is the infrared spectrum of the phosphoric acid esterification product in the embodiment 1 of the application;

[0045] Figure 4 is the nuclear magnetic resonance phosphorus spectrum of the phosphoric acid esterification product in the embodiment 1 of the application;

[0046] Figure 5 is the cone calorimeter test result graph of the application;

[0047] Figure 6is a schematic diagram of the product after the combustion test of application example 1 and application example 4 of the present application;

[0048] wherein, Figure 6 is a schematic diagram of the product of application example 4, Figure 6 is a schematic diagram of the product of application example 1. DETAILED DESCRIPTION

[0049] The present application is further described below in conjunction with the accompanying drawings and examples. Unless otherwise defined, technical or scientific terms used in the present application should be understood as having the meaning commonly understood by one of ordinary skill in the art to which the present application pertains. The features mentioned in the present application or the features mentioned in the specific examples mentioned above can be combined in any manner, and these specific examples are only used to illustrate the present application and are not used to limit the scope of the present application.

[0050] Example 1

[0051] S1, mix phytic acid 0.02 mol and trimethyl phosphine oxide 0.06 mol, phosphate esterification reaction at 150℃ for 5h to obtain phosphate esterification product;

[0052] S2, mix the phosphate esterification product with water 50mL, then add urea 0.12 mol, salt formation reaction at 85℃ for 8h to obtain the multivalent phosphorus-containing modifier.

[0053] The flow chart of the preparation method of the multivalent phosphorus-containing modifier provided in Example 1 is shown in Figure 1 .

[0054] Example 2

[0055] S1, mix phytic acid 0.02 mol and trimethyl phosphine oxide 0.06 mol, phosphate esterification reaction at 150℃ for 5h to obtain phosphate esterification product;

[0056] S2, mix the phosphate esterification product with water 50mL, then add 3,5-diamino-1,2,4-triazole 0.12 mol, salt formation reaction at 85℃ for 8h to obtain the multivalent phosphorus-containing modifier.

[0057] The flow chart of the preparation method of the multivalent phosphorus-containing modifier provided in Example 2 is shown in Figure 2 .

[0058] Example 3

[0059] S1, mix phytic acid 0.02 mol and trimethyl phosphine oxide 0.06 mol, phosphate esterification reaction at 150℃ for 5h to obtain phosphate esterification product;

[0060] S2, after mixing the phosphonate product with water 50 mL, 2, 4-diamino-6- hydroxypyrimidine 0.1 mol was added, and a salt reaction was carried out at 120°C for 3h to obtain the polyvalent phosphorus-containing modifier.

[0061] Example 4

[0062] S1, phenyl phosphate 0.01 mol and trimethylol phosphine oxide 0.06 mol were mixed, and a phosphonate reaction was carried out at 120°C for 4h to obtain the phosphonate product;

[0063] S2, after mixing the phosphonate product with ethanol 40 mL, 2, 4-diamino-6- hydroxypyrimidine 0.08 mol was added, and a salt reaction was carried out at 80°C for 10h to obtain the polyvalent phosphorus-containing modifier.

[0064] Example 5

[0065] S1, phenyl phosphate 0.02 mol and trimethylol phosphine oxide 0.05 mol were mixed, and a phosphonate reaction was carried out at 140°C for 5h to obtain the phosphonate product;

[0066] S2, after mixing the phosphonate product with tetrahydrofuran 100 mL, N-aminoethyl piperazine 0.2 mol was added, and a salt reaction was carried out at 85°C for 5h to obtain the polyvalent phosphorus-containing modifier.

[0067] Comparative Example 1

[0068] S1, phytic acid 0.02 mol and urea 0.12 mol were dissolved in 50 mL of water, and stirred at 85°C for 8h to obtain the modifier.

[0069] Application Example 1

[0070] The polyvalent phosphorus-containing modifier prepared in Example 1 was dissolved in ethanol (impregnation solution), and the mass concentration of the polyvalent phosphorus-containing modifier in the impregnation solution was 30%, then carbon fibers were placed in the above-mentioned impregnation solution, soaked for 10h and dried to obtain modified fiber material, and the modified fiber material was mixed with polyamide, solidified to obtain a fiber-reinforced polymer.

[0071] Application Example 2

[0072] The polyvalent phosphorus-containing modifier prepared in Example 2 was dissolved in ethanol (impregnation solution), and the mass concentration of the polyvalent phosphorus-containing modifier in the impregnation solution was 30%, then carbon fibers were placed in the above-mentioned impregnation solution, soaked for 10h and dried to obtain modified fiber material, and the modified fiber material was mixed with polyamide, solidified to obtain a fiber-reinforced polymer.

[0073] Application Example 3

[0074] The fiber reinforced polymer prepared in Comparative Example 1 was dissolved in ethanol (impregnation solution) with a mass concentration of 30% of the fiber reinforced polymer in the impregnation solution, and then the carbon fibers were placed in the impregnation solution, soaked for 10 h and dried to obtain a modified fiber material. The modified fiber material was mixed with polyamide and cured to obtain a fiber reinforced polymer.

[0075] Application Example 4

[0076] The carbon fibers were mixed with polyamide and cured to obtain a fiber polymer composite material.

[0077] Test

[0078] The phosphate esterification product obtained in Example 1, S1 was subjected to infrared spectrum detection, and the results are shown in Figure 3 From Figure 3 it can be seen that characteristic peaks of phosphate ester bonds appear at 1121 cm -1 and 1044 cm -1 , indicating that the phosphate esterification reaction of phytic acid and trimethyl phosphine oxide is successful.

[0079] The phosphate esterification product obtained in Example 1, S1 was subjected to nuclear magnetic detection, and the nuclear magnetic resonance phosphorus spectrum is shown in Figure 4 From Figure 4 it can be seen that phosphorus peaks of phosphate and phosphine oxide structures appear at 0.47 ppm and 49.10 ppm, respectively, indicating the successful combination of the two structures.

[0080] The products obtained in Application Example 1, Application Example 3 and Application Example 4 were subjected to combustion test, and the results of the cone calorimeter test are shown in Figure 5 From Figure 5 it can be seen that the peak heat release rate of the fiber polymer composite material prepared in Application Example 4 is 169.7 W / g, the peak heat release rate of the fiber reinforced polymer prepared in Application Example 3 is 123.5 W / g, and the peak heat release rate of the product prepared in Application Example 1 is 90.92 W / g, which is significantly lower than that of Application Example 2 and Application Example 3. This shows that the multivalent phosphorus-containing modifier prepared in Example 1 can significantly improve the flame retardant performance, and the flame retardant effect is more excellent than that of a single phosphorus structure (the modifier prepared in Comparative Example 1).

[0081] The products obtained in Application Example 1 and Application Example 4 were subjected to combustion test, and the schematic diagram of the product morphology is shown in Figure 6 From Figure 6It can be seen that the fiber polymer composite prepared in application example 4 has cracking phenomenon between fibers after combustion, indicating that the carbon layer between the interfaces is not tightly connected; the fiber reinforced polymer prepared in application example 1 forms a tightly connected carbon layer in the interface region of the fiber and the resin after combustion, effectively inhibiting the interface cracking, which is because the polar groups in the multivalent phosphorus-containing modifier prepared in example 1 are combined with the fiber surface and the resin at the same time through hydrogen bonding, improving the interfacial bonding strength, and the positive five-valent phosphorus and negative one-valent phosphorus contained in the structure synergistically inhibit the flame-retardant effect, promoting the formation of a stable carbon layer in the interface region during combustion, effectively inhibiting the interface cracking.

[0082] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand: it can still modify or equivalently replace the technical solutions of the present application, and these modifications or equivalent replacements also cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for preparing a multivalent phosphorus-containing modifier, characterized in that, The preparation steps include the following: S1. A phosphoric acid compound is mixed with a phosphorus-containing and hydroxyl-containing compound and subjected to a phosphorylation reaction to obtain a phosphorylation product. S2. After mixing the phosphoric acid esterification product with a solvent, a nitrogen-containing compound is added to form a salt, which yields a multivalent phosphorus-containing modifier. The valence state of phosphorus differs between phosphoric acid compounds and phosphorus-containing or hydroxyl-containing compounds. The phosphoric acid compound in S1 is phytic acid; The phosphorus-containing and hydroxyl-containing compound is tris(hydroxymethyl)phosphine oxide; The nitrogen-containing compound in S2 is selected from one or more of the following: urea, 3,5-diamino-1,2,4-triazole, 2,4-diamino-6-hydroxypyrimidine, N-aminoethylpiperazine, 1-methanesulfonylpiperazine, melamine, and dicyandiamide. The structural formula of the phosphorylation product is: 。 2. The method for preparing a multivalent phosphorus-containing modifier according to claim 1, characterized in that, The molar ratio of phosphoric acid compounds to phosphorus-containing hydroxyl compounds in S1 is 1:2-6.

3. The method for preparing a multivalent phosphorus-containing modifier according to claim 1, characterized in that, The temperature for the phosphorylation reaction in S1 is 120-180℃, and the reaction time is 2-10h.

4. The method for preparing a multivalent phosphorus-containing modifier according to claim 1, characterized in that, The solvent in S2 includes one or more of the following: water, ethanol, tetrahydrofuran, dichloromethane, N,N-dimethylformamide, etc. The molar volume ratio of the phosphoric acid compound to the solvent is 0.02 mol: 30-100 mL.

5. The method for preparing a multivalent phosphorus-containing modifier according to claim 1, characterized in that, The molar ratio of nitrogen-containing compounds to phosphoric acid-containing compounds is 0.1-0.2:0.

02.

6. The method for preparing a multivalent phosphorus-containing modifier according to claim 1, characterized in that, The salt formation reaction in S2 takes place at a temperature of 20-120℃ and for a time of 3-10 hours.

7. A multivalent phosphorus-containing modifier prepared by the preparation method of the multivalent phosphorus-containing modifier according to any one of claims 1-6.

8. The application of the multivalent phosphorus-containing modifier according to claim 7 in flame retardants or surface modifiers.

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