Preparation process of fiber flame retardant
By using chitosan and lignin in fiber flame retardants to form a carbon layer, the problem of exhaustion of fiber flame retardants in the early stage of the fire is solved, its thermal stability and flame retardant properties are improved, the reaction time is extended, and the reaction time is reduced The risk of fire spreading.
Patent Information
- Application Number
- CN202411271453.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2024-12-10
AI Technical Summary
The fiber flame retardant is consumed in the early stages of the fire, resulting in a rapid decline in the flame retardant performance of the material, increasing the risk of fire spread.
Chitosan and lignin are used as modifiers to generate carbon layers through gelation reaction and pyrolysis, which improves the thermal stability and oxygen isolation of the fiber flame retardant and extends the reaction time.
By generating the thermal insulation and oxygen insulation properties of the carbon layer, the thermal stability and flame retardant properties of the fiber flame retardant are improved, and the rapid reaction is reduced at high temperatures and the reaction time is extended.
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Abstract
Description
Technical Field
[0001] The present application relates to the field of a preparation process of a fiber flame retardant, and to the field of flame retardants. Background Art
[0002] At present, fiber flame retardants can form a protective film on the fiber surface when a fire occurs. This film can isolate oxygen and heat and slow down the spread of fire.
[0003] However, fiber flame retardants are extremely unstable at high temperatures. In the early stages of a fire, the flame retardant may react quickly with the fire source and be consumed, causing the flame retardant properties of the material to rapidly decrease under the continued action of the fire source. Once the flame retardant has reacted, the fiber material will lose its additional protection and be vulnerable to direct attack by the flame, increasing the risk of fire spreading.
[0004] With respect to the above-mentioned related technologies, the inventors believe that the fiber flame retardant has the defect that it is completely consumed in the early stage of a fire. Summary of the invention
[0005] In order to improve the defect that the fiber flame retardant will be consumed in the early stage of a fire, the present application provides a preparation process of a fiber flame retardant The present application provides a preparation process of a fiber flame retardant, which adopts the following technical scheme: A preparation process of a fiber flame retardant comprises the following steps: Adding a catalyst and Y-glycidyloxypropyltrimethoxysilane to a 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline solution, and obtaining a crude solid flame retardant after an impurity removal process; Adding a modifier to a crude solid flame retardant, performing a gelation reaction, and drying to obtain a fiber flame retardant; Modifying agents include chitosan.
[0006] By adopting the above technical scheme, chitosan is used as a modified fiber flame retardant. When a fire occurs, it decomposes at high temperature to generate a carbon layer. This carbon layer has good thermal insulation and oxygen isolation properties, improves the thermal stability of the fiber flame retardant, and reduces the occurrence of the fiber flame retardant reacting quickly under high temperature conditions.
[0007] Preferably, the mass ratio of the crude solid flame retardant to chitosan is 10:5-8; and the pH of the chitosan solution is 3.5-4.0.
[0008] By adopting the above technical solution, when the mass ratio of crude solid flame retardant to chitosan is 10:5-8, increasing the amount of chitosan will help improve the flame retardant properties of the flame retardant. When the amount of chitosan added is too little, the chitosan cannot completely cover the surface of the flame retardant under high temperature conditions; when the amount of chitosan added is too much, it will affect the flame retardant properties of the fiber flame retardant itself. The solubility of chitosan is enhanced in acidic conditions, which helps chitosan adhere to the surface of the fiber flame retardant.
[0009] Preferably, the modifying agent further comprises lignin.
[0010] By adopting the above technical solution, lignin can form a relatively stable carbon layer during the pyrolysis process. This carbon layer has the properties of heat insulation and oxygen isolation, which can effectively prevent heat and oxygen from being transferred to the inside of the fiber flame retardant, further prolonging the reaction time of the fiber flame retardant and improving the flame retardant properties of the fiber flame retardant.
[0011] Preferably, the mass ratio of the crude solid flame retardant to lignin is 10:5-10.
[0012] By adopting the above technical scheme, when the mass ratio of crude solid flame retardant to lignin is 10:5-10, increasing the amount of lignin added can improve the flame retardant properties of the fiber flame retardant; when the amount of lignin added is too little, it cannot completely cover the surface of the fiber flame retardant under high temperature conditions; when the amount of lignin added is too much, it will cause the fiber flame retardant to react untimely, thereby reducing the flame retardant properties of the flame retardant.
[0013] Preferably, adding γ-glycidyloxypropyltrimethoxysilane to the 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline solution comprises the following steps: Dissolving 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline in dimethylformamide to prepare a 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline solution; adding a catalyst to the 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline solution and then adding 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline dropwise; The mass ratio of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline to Y-glycidyl ether oxypropyl trimethoxy silane is 5-8:10-12; and the reaction temperature is 70-80°C.
[0014] Preferably, the catalyst is formic acid.
[0015] By adopting the above technical solution, formic acid has a strong dehydration ability when used as a catalyst, thereby promoting the reaction of the fiber flame retardant in the positive direction.
[0016] Preferably, the mass ratio of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline to the catalyst is 5-8:1.7-3.4.
[0017] By adopting the above technical scheme, the mass ratio of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline to the catalyst is 5-8:1.7-3.4, and the flame retardant performance of the flame retardant is good; excessive formic acid may cause excessive dehydration reaction, resulting in the destruction of the chemical structure of the flame retardant or excessive cross-linking, thereby affecting its dispersibility and compatibility in the fiber; insufficient formic acid will lead to incomplete synthesis reaction of the flame retardant, affecting the performance and flame retardant effect of the final product.
[0018] Preferably, the gelation reaction comprises the following steps: preparing a lignin-chitosan mixed solution, and adjusting the pH of the lignin-chitosan mixed solution to 7; adding a crude solid flame retardant into the lignin-chitosan mixture; Continue to add gelling agent hexamethylene diisocyanate to form a gel flame retardant; Ethanol was added to the gel flame retardant to remove impurities.
[0019] By adopting the above technical solution, the active isocyanate group of hexamethylene diisocyanate can react with the hydroxyl or amino groups in chitosan and lignin to form a stable polyurethane network structure. This network structure can improve the thermal stability and flame retardant properties of the material.
[0020] Preferably, the mass ratio of the crude solid flame retardant to the gelling agent is 10:2-3.
[0021] By adopting the above technical scheme, when the amount of hexamethylene diisocyanate added is too much, the hydroxyl or amino groups in the raw materials will be over-occupied, thereby affecting the flame retardant properties of chitosan and lignin; when the amount of hexamethylene diisocyanate added is too little, it will lead to incomplete cross-linking reaction, causing the flame retardant properties of the flame retardant to decrease.
[0022] Preferably, the impurity removal process comprises the following steps: The reaction solution of Y-glycidyloxypropyltrimethoxysilane and 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline was cooled to room temperature; The reaction solution is centrifuged to retain the solid product, dimethylformamide and ethanol / water mixed solution are added to the solid product for washing, and the solid product is dried to obtain a crude solid flame retardant.
[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. Chitosan is used as the fiber flame retardant modification. When a fire occurs, it decomposes at high temperature to form a carbon layer. This carbon layer has good thermal insulation and oxygen isolation, improves the thermal stability of the fiber flame retardant, and reduces the occurrence of the fiber flame retardant reacting quickly under high temperature conditions; 2. Lignin can form a relatively stable carbon layer during the pyrolysis process. This carbon layer has the characteristics of heat insulation and oxygen isolation, which can effectively prevent heat and oxygen from being transferred to the inside of the fiber flame retardant, further prolong the reaction time of the fiber flame retardant, and improve the flame retardant performance of the fiber flame retardant; 3. The active isocyanate group of hexamethylene diisocyanate can react with the hydroxyl or amino groups in chitosan and lignin to form a stable polyurethane network structure. This network structure can improve the thermal stability and flame retardant properties of the material. DETAILED DESCRIPTION
[0024] The present application is further described in detail below with reference to the embodiments. Example
[0025] Example 1 S1. Measure 100 mL of dimethylformamide and pour it into a round-bottom flask. Weigh 6 g of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline and add it to the dimethylformamide under stirring for 20 min to obtain a 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline solution.
[0026] S2. Continue to add 3 mL of 85% formic acid solution to the 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline solution and stir evenly to obtain an acidic solution of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline.
[0027] S3. Weigh 11 g of Y-glycidyloxypropyltrimethoxysilane. Add Y-glycidyloxypropyltrimethoxysilane dropwise to the acidic solution of 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline at a rate of 0.5 drops per second in a 70°C water bath. After the addition is complete, continue the reaction in a 70°C water bath for 4 hours.
[0028] S4. After the reaction is completed, the reaction solution of Y-glycidyloxypropyltrimethoxysilane and 2-sulfonic acid-4-β-sulfate ethylsulfoneaniline is taken out and naturally cooled to room temperature.
[0029] S5. Put the reaction solution cooled to room temperature into a centrifuge bottle, centrifuge at 3000r / min for 10min, and retain the solid product after centrifugation. Add 50mL of dimethylformamide to the solid product for 10min, then use a mixed solution of ethanol / water with a volume ratio of 1:1 to continue washing for 10min, and then put it into a vacuum drying oven at 50℃ for 24 hours to obtain a crude solid flame retardant.
[0030] S6. Weigh 6 g of chitosan and add it to 100 ml of deionized water. Add 0.1 mol / L HCl solution to adjust the pH to 3.5. Stir in a 50°C water bath for 60 min to form a chitosan solution.
[0031] S7. Weigh 8 g of lignin powder and add it to 100 ml of deionized water, stir for 60 min to form a suspension. Add the suspension to the chitosan solution, add 0.1 mol / L HCl solution or 0.1 mol / L NaOH solution to the mixed solution to adjust the solution to pH 7, and obtain a lignin-chitosan mixed solution.
[0032] S8. Add 10 g of crude solid flame retardant to the lignin-chitosan mixture, and continue to add 2.5 g of hexamethylene diisocyanate to form a gel flame retardant.
[0033] S9. Add 200 mL of ethanol to the gel flame retardant and place it in a 40°C constant temperature water bath oscillator for curing for 24 hours. Filter and retain the solid matter in the above liquid-solid mixture and rinse it with ethanol. Place the rinsed solid matter in a 60°C drying oven and dry it for 4 hours to obtain a fiber flame retardant.
[0034] Example 2 S1. Measure 120 mL of dimethylformamide and pour it into a round-bottom flask. Weigh 6 g of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline and add it to the dimethylformamide under stirring for 20 min to obtain a 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline solution.
[0035] S2. Continue to add 3 mL of 85% formic acid solution to the 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline solution and stir evenly to obtain an acidic solution of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline.
[0036] S3. Weigh 11 g of Y-glycidyloxypropyltrimethoxysilane. Add Y-glycidyloxypropyltrimethoxysilane dropwise to the acidic solution of 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline at a rate of 0.5 drops per second in a water bath at 80°C. After the addition is complete, continue the reaction in a water bath at 80°C for 6 hours.
[0037] S4. After the reaction is completed, the reaction solution of Y-glycidyloxypropyltrimethoxysilane and 2-sulfonic acid-4-β-sulfate ethylsulfoneaniline is taken out and naturally cooled to room temperature.
[0038] S5. Put the reaction solution cooled to room temperature into a centrifuge bottle, centrifuge at 3000r / min for 15min, and retain the solid product after centrifugation. Add 50mL of dimethylformamide to the solid product for 15min, then use a mixed solution of ethanol / water with a volume ratio of 1:1 to continue washing for 15min, and then put it into a vacuum drying oven at 50℃ for 24 hours to obtain a crude solid flame retardant.
[0039] S6. Weigh 6 g of chitosan and add it to 100 ml of deionized water. Add 0.1 mol / L HCl solution to adjust the pH to 4.0. Stir in a 60°C water bath for 60 min to form a chitosan solution.
[0040] S7. Weigh 8 g of lignin powder and add it to 100 ml of deionized water, stir for 80 min to form a suspension. Add the suspension to the chitosan solution, add 0.1 mol / L HCl solution or 0.1 mol / L NaOH solution to the mixed solution to adjust the solution to pH 7, and obtain a lignin-chitosan mixed solution.
[0041] S8. Add 10 g of crude solid flame retardant to the lignin-chitosan mixture, and continue to add 2.5 g of hexamethylene diisocyanate to form a gel flame retardant.
[0042] S9. Add 300 mL of ethanol to the gel flame retardant and place it in a 50°C constant temperature water bath oscillator for curing for 24 hours. Filter and retain the solid matter in the above liquid-solid mixture and rinse it with ethanol. Place the rinsed solid matter in a 60°C drying oven and dry it for 6 hours to obtain a fiber flame retardant.
[0043] Example 3 S1. Measure 110 mL of dimethylformamide and pour it into a round-bottom flask. Weigh 6 g of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline and add it to the dimethylformamide under stirring for 20 min to obtain a 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline solution.
[0044] S2. Continue to add 3 mL of 85% formic acid solution to the 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline solution and stir evenly to obtain an acidic solution of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline.
[0045] S3. Weigh 11 g of Y-glycidyloxypropyltrimethoxysilane. Add Y-glycidyloxypropyltrimethoxysilane dropwise to the acidic solution of 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline at a rate of 0.5 drops per second in a 75°C water bath. After the addition is complete, continue the reaction in a 75°C water bath for 5 hours.
[0046] S4. After the reaction is completed, the reaction solution of Y-glycidyloxypropyltrimethoxysilane and 2-sulfonic acid-4-β-sulfate ethylsulfoneaniline is taken out and naturally cooled to room temperature.
[0047] S5. Put the reaction solution cooled to room temperature into a centrifuge bottle, centrifuge at 3000r / min for 13min, and retain the solid product after centrifugation. Add 50mL of dimethylformamide to the solid product for 13min, then use a mixed solution of ethanol / water with a volume ratio of 1:1 to continue washing for 13min, and then put it into a vacuum drying oven at 50℃ for 24 hours to obtain a crude solid flame retardant.
[0048] S6. Weigh 6 g of chitosan and add it to 100 ml of deionized water. Add 0.1 mol / L HCl solution to adjust the pH to 3.8. Stir in a 55°C water bath for 60 min to form a chitosan solution.
[0049] S7. Weigh 8 g of lignin powder and add it to 100 ml of deionized water, stir for 70 min to form a suspension. Add the suspension to the chitosan solution, add 0.1 mol / L HCl solution or 0.1 mol / L NaOH solution to the mixed solution to adjust the solution to pH 7, and obtain a lignin-chitosan mixed solution.
[0050] S8. Add 10 g of crude solid flame retardant to the lignin-chitosan mixture, and continue to add 2.5 g of hexamethylene diisocyanate to form a gel flame retardant.
[0051] S9. Add 250 mL of ethanol to the gel flame retardant and place it in a 45°C constant temperature water bath oscillator for curing for 24 hours. Filter and retain the solid matter in the above liquid-solid mixture and rinse it with ethanol. Place the rinsed solid matter in a 60°C drying oven and dry it for 5 hours to obtain a fiber flame retardant.
[0052] Example 4 The difference between Example 4 and Example 1 is that the added amount of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline is 5 g.
[0053] Example 5 The difference between Example 5 and Example 1 is that the added amount of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline is 8 g.
[0054] Example 6 The difference between Example 6 and Example 1 is that the added amount of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline is 3 g.
[0055] Example 7 The difference between Example 7 and Example 1 is that the added amount of 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline is 10 g.
[0056] Example 8 The difference between Example 8 and Example 1 is that the added amount of 2Y-glycidyloxypropyltrimethoxysilane is 10 g.
[0057] Example 9 The difference between Example 9 and Example 1 is that the added amount of 2Y-glycidyloxypropyltrimethoxysilane is 12 g.
[0058] Example 10 The difference between Example 10 and Example 1 is that the added amount of 2Y-glycidyloxypropyltrimethoxysilane is 6 g.
[0059] Embodiment 11 The difference between Example 11 and Example 1 is that the amount of 2Y-glycidyloxypropyltrimethoxysilane added is 15 g.
[0060] Example 12 The difference between Example 12 and Example 1 is that the added amount of 2Y-glycidyloxypropyltrimethoxysilane is 15 g.
[0061] Embodiment 13 The difference between Example 13 and Example 1 is that 2 mL of 85% formic acid solution is added.
[0062] Embodiment 14 The difference between Example 14 and Example 1 is that 4 mL of 85% formic acid solution is added.
[0063] Embodiment 15 The difference between Example 15 and Example 1 is that 1 mL of 85% formic acid solution is added.
[0064] Example 16 The difference between Example 16 and Example 1 is that 5 mL of 85% formic acid solution is added.
[0065] Embodiment 17 The difference between Example 17 and Example 1 is that 3 mL of 85% acetic acid solution is added.
[0066] Embodiment 18 The difference between Example 18 and Example 1 is that 3 mL of 85% propionic acid solution is added.
[0067] Embodiment 19 The difference between Example 19 and Example 1 is that the added amount of chitosan is 5 g.
[0068] Embodiment 20 The difference between Example 20 and Example 1 is that the added amount of chitosan is 8 g.
[0069] Embodiment 21 The difference between Example 21 and Example 1 is that the amount of lignin added is 5 g.
[0070] Embodiment 22 The difference between Example 22 and Example 1 is that the amount of lignin added is 10 g.
[0071] Embodiment 23 The difference between Example 23 and Example 1 is that the added amount of lignin is 3 g.
[0072] Embodiment 24 The difference between Example 24 and Example 1 is that the amount of lignin added is 13 g.
[0073] Embodiment 25 The difference between Example 25 and Example 1 is that lignin is replaced by cellulose of the same mass.
[0074] Embodiment 26 The difference between Example 26 and Example 1 is that the added amount of hexamethylene diisocyanate is 2 g.
[0075] Embodiment 27 The difference between Example 27 and Example 1 is that the added amount of hexamethylene diisocyanate is 3 g.
[0076] Embodiment 28 The difference between Example 28 and Example 1 is that the added amount of hexamethylene diisocyanate is 1 g.
[0077] Embodiment 29 The difference between Example 29 and Example 1 is that the added amount of hexamethylene diisocyanate is 5 g.
[0078] Embodiment 30 The difference between Example 30 and Example 1 is that hexamethylene diisocyanate is replaced by toluene diisocyanate of equal mass.
[0079] Embodiment 31 The difference between Example 31 and Example 1 is that hexamethylene diisocyanate is replaced by polyisocyanate of equal mass.
[0080] Embodiment 32 The difference between Example 32 and Example 1 is that hexamethylene diisocyanate is replaced by an epoxy resin of equal mass.
[0081] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the added amount of chitosan is 3 g.
[0082] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the added amount of chitosan is 10 g.
[0083] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that chitosan is replaced by cellulose of the same mass.
[0084] Performance testing The limiting oxygen index (LOI) of the fiber flame retardants in Examples 1-32 and Comparative Examples 1-3 was measured with reference to GB / T 2406.2-2009. The specific test results are shown in Table 1.
[0085] Table 1 Limiting oxygen index of Examples 1-32 and Comparative Examples 1-3 It can be seen from Examples 1-12 that the addition amount of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline and 2Y-glycidyloxypropyltrimethoxysilane has little effect on the limiting oxygen index of the flame retardant.
[0086] It can be seen from Example 1 and Examples 13-18 that when the amount of formic acid solution added is 2-4 mL, the limiting oxygen index of the flame retardant gradually increases with the increase in the amount of formic acid solution added; when the amount of formic acid solution added is outside the range of 2-4 mL, the limiting oxygen index of the flame retardant decreases; when acetic acid or propionic acid is selected as the catalyst, the limiting oxygen index of the flame retardant is significantly reduced.
[0087] It can be seen from Example 1, Examples 19-20, and Comparative Examples 1-3 that when the amount of chitosan added is 5-8 g, the limiting oxygen index of the flame retardant gradually increases with the increase in the amount of chitosan added; when the amount of chitosan added is outside the range of 5-8 g, the limiting oxygen index of the flame retardant decreases; after using cellulose instead of chitosan, the limiting oxygen index of the flame retardant is significantly reduced.
[0088] It can be seen from Example 1 and Examples 21-25 that when the amount of lignin added is 5-10g, the limiting oxygen index of the flame retardant gradually increases with the increase in the amount of cellulose added; when the amount of lignin added is outside the range of 5-10g, the limiting oxygen index of the flame retardant decreases; after using cellulose instead of lignin, the limiting oxygen index of the flame retardant is significantly reduced.
[0089] It can be seen from Example 1 and Examples 26-32 that when the amount of hexamethylene diisocyanate added is 2-3g, the limiting oxygen index of the flame retardant does not change much; when the amount of hexamethylene diisocyanate added is outside the range of 5-10g, the limiting oxygen index of the flame retardant decreases; after replacing hexamethylene diisocyanate with toluene diisocyanate, polyisocyanate, and epoxy resin, respectively, the limiting oxygen index of the flame retardant is significantly reduced.
[0090] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.
Claims
1. A preparation process of a fiber flame retardant, characterized in that: The steps include: Adding a catalyst and Y-glycidyloxypropyltrimethoxysilane to a 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline solution, and obtaining a crude solid flame retardant after an impurity removal process; Adding a modifier to a crude solid flame retardant, performing a gelation reaction, and drying to obtain a fiber flame retardant; Modifying agents include chitosan.
2. The preparation process of a fiber flame retardant according to claim 1, characterized in that: The mass ratio of the crude solid flame retardant to chitosan is 10:5-8; the pH value of the chitosan solution is 3.5-4.
0.
3. The preparation process of a fiber flame retardant according to claim 1 or 2, characterized in that: Modifying agents also include lignin.
4. The preparation process of a fiber flame retardant according to claim 3, characterized in that: The mass ratio of the crude solid flame retardant to the lignin is 10:5-10.
5. The preparation process of a fiber flame retardant according to claim 1, characterized in that: Adding γ-glycidyloxypropyltrimethoxysilane to the 2-sulfonic acid-4-β-sulfate ethylsulfoneaniline solution comprises the following steps: Dissolving 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline in dimethylformamide to prepare a 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline solution; adding a catalyst to the 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline solution and then adding 2-sulfonic acid-4-β-sulfate ethyl sulfonyl aniline dropwise; The mass ratio of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline to Y-glycidyl ether oxypropyl trimethoxy silane is 5-8:10-12; and the reaction temperature is 70-80°C.
6. The preparation process of a fiber flame retardant according to claim 1, characterized in that: The catalyst is formic acid.
7. The preparation process of a fiber flame retardant according to claim 1 or 5, characterized in that: The mass ratio of 2-sulfonic acid-4-β-sulfate ethyl sulfone aniline to the catalyst is 5-8:1.7-3.
4.
8. The preparation process of a fiber flame retardant according to claim 4, characterized in that: The gelation reaction includes the following steps: preparing a lignin-chitosan mixed solution, and adjusting the pH of the lignin-chitosan mixed solution to 7; adding a crude solid flame retardant into the lignin-chitosan mixture; Continue to add gelling agent hexamethylene diisocyanate to form a gel flame retardant; Ethanol was added to the gel flame retardant to remove impurities.
9. The preparation process of a fiber flame retardant according to claim 8, characterized in that: The mass ratio of the crude solid flame retardant to the gelling agent is 10:2-3.
10. The preparation process of a fiber flame retardant according to claim 1, characterized in that: The impurity removal process includes the following steps: The reaction solution of Y-glycidyloxypropyltrimethoxysilane and 2-sulfonic acid-4-β-sulfate ethylsulfonylaniline was cooled to room temperature; The reaction solution is centrifuged to retain the solid product, dimethylformamide and ethanol / water mixed solution are added to the solid product for washing, and the solid product is dried to obtain a crude solid flame retardant.