Flame retardant and preparation process thereof
By using raw materials such as lignin and ferrosilicon copolymers, an efficient flame retardant containing a variety of functional groups of flame retardant elements is formed, which solves the problems of poor interfacial compatibility and environmental pollution in biomass foamed materials, and achieves the dual goals of efficient flame retardant and environmental protection.
Patent Information
- Application Number
- CN202411998013.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-05-23
AI Technical Summary
In the case of flame retardant, existing flame retardant agents have poor interface compatibility when foaming materials, resulting in low flame retardant efficiency and durability, and are highly polluted to the environment.
Using lignin and ferrosilicon copolymer as the basic raw materials, functional monomers are introduced through initiators, and polymers with a three-dimensional spatial network structure are formed through crosslinking agents. Finally, inorganic flame retardant is introduced under the action of silane coupling agents to form a high-efficiency flame retardant containing a variety of functional groups of flame retardant elements.
It achieves the efficient flame retardant effect of flame retardant, and has the advantages of easy degradation and environmentally friendly, improving the flame retardant performance and sustainability of the material.
Smart Images
Figure BDA0005225224680000061 
Figure BDA0005225224680000071
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of flame retardants, and in particular, relates to a flame retardant and a preparation process thereof. Background Art
[0002] Flame retardants can be divided into three types according to their principles: (1) Reactive flame retardants, which are modified by grafting and cross-linking to graft functional groups containing flame retardant elements such as nitrogen, phosphorus, and silicon onto biomass raw materials. The flame retardant directly participates in the foaming process of the foaming material. The two have strong interfacial compatibility and have little effect on the integrity of the foaming material; (2) Additive flame retardants, as an additive, have more structural options; (3) Coating flame retardants, which are evenly dispersed on the surface of the foaming material through surface coating. The disadvantage of reactive flame retardants is that they have a single structure and a complex synthesis method. The disadvantages of additive flame retardants and coating flame retardants are that the interfacial compatibility between the flame retardant and the foaming material is poor, resulting in low flame retardant efficiency and durability of the flame retardant, thereby affecting the flame retardancy of the internal foaming material. When the surface of the coating flame retardant is damaged or destroyed, it will lose its flame retardant effect. Therefore, it is difficult to use coating flame retardants in flame retardant biomass foaming materials.
[0003] At present, environmentally friendly flame retardants have become a hot topic of research, which aims to reduce the potential harm of traditional flame retardants to the environment through green chemical approaches. The emergence of new flame retardants such as phosphorus-based compounds, carbon-based materials (such as graphene, carbon nanotubes), bio-based flame retardants, silicon-containing compounds, nanocomposites, and additives containing specific metal ions have not only effectively improved the flame retardant properties of EP, but also promoted the sustainable development of materials science. Summary of the invention
[0004] The primary purpose of the present invention is to provide a flame retardant and a preparation process thereof, so as to achieve good flame retardant effect of the flame retardant and be environmentally friendly.
[0005] To this end, the present invention provides the following technical solutions.
[0006] One aspect of the present invention provides a process for preparing a flame retardant, the process comprising the following steps:
[0007] Dissolving lignin in an alkaline solution with a pH value between 12 and 14 to obtain a lignin alkaline solution with a concentration of 10 to 50 wt%; adding ferrosilicon copolymer to the lignin alkaline solution in a mass volume ratio of 1 g: 10 to 30 mL and ultrasonically dispersing the copolymer to obtain a suspension;
[0008] Add the functional monomer and the initiator to the suspension, stir and react at 30-120° C. for 3-6 hours, then add the crosslinking agent and continue stirring for 4-6 hours, let stand for 30-60 minutes after the stirring, then filter, wash and dry the obtained solid product to obtain product I;
[0009] The obtained product I and the inorganic flame retardant are added to a 1-3 wt% silane coupling agent / ethanol solution according to a mass volume ratio of 1g: 3-5g: 40-100mL, and stirred at a speed of 200-400rpm for 1-3h. After the reaction is completed, the mixture is filtered, and the obtained solid product is washed and dried to obtain a final product.
[0010] In some preferred embodiments, the lignin is selected from one or more of alkali lignin, lignin sulfonate, rice husk lignin, and bamboo lignin.
[0011] In some preferred embodiments, the base is sodium hydroxide and / or potassium hydroxide.
[0012] In some preferred embodiments, the ferrosilicon copolymer is formed by polymerizing sodium silicate and ferrate in a molar ratio of 1:0.5-2.
[0013] In some preferred embodiments, the functional monomer is selected from one or a mixture of two or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, N-phenylethyl acrylamide, N-octyl propionamide, N-tetradecyl acrylamide, N,N-dioctyl acrylamide, N,N-dihexyl acrylamide, N,N-di-n-octyl acrylamide and N,N-di-n-dodecyl acrylamide.
[0014] In some preferred embodiments, the added amount of the functional monomer is 0.5 to 1 times the mass of the lignin.
[0015] In some preferred embodiments, the initiator is selected from one of ammonium persulfate, potassium persulfate, sodium persulfate, azobisisobutyronitrile, azobisisoheptanenitrile, and azobisisobutyramidine hydrochloride.
[0016] In some preferred embodiments, the amount of the initiator added is 0.2-0.7% of the mass of the functional monomer.
[0017] In some preferred embodiments, the cross-linking agent is selected from any one of hydroquinone, resorcinol, and catechol.
[0018] In some preferred embodiments, the amount of the cross-linking agent added is 0.1-0.3% of the mass of the functional monomer.
[0019] In some preferred embodiments, the inorganic flame retardant is selected from one or more of monoammonium phosphate, diammonium phosphate, and urea.
[0020] In some preferred embodiments, the silane coupling agent is selected from one of bis(triethoxysilyl)methane, bis(triethoxysilyl)ethane, (triethoxysilyl)methanol and (triethoxysilyl)methane.
[0021] Another aspect of the present invention also provides a flame retardant prepared according to the preparation process as described above.
[0022] By means of the above technical scheme, the present invention has at least the following advantages: the present invention uses lignin and ferrosilicon copolymer as basic raw materials, introduces functional monomers through an initiator, forms a polymer with a three-dimensional network structure through a crosslinking agent, and finally introduces an inorganic flame retardant into the polymer under the action of a silane coupling agent, so that the obtained product contains functional groups of multiple flame retardant elements such as nitrogen, phosphorus, and silicon at the same time, thereby having a better flame retardant effect. The flame retardant of the present invention has the advantages of being easy to degrade and having little pollution to the environment, and has a high economic value.
[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION
[0024] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0025] Unless otherwise specified, the percentage content involved in the present invention refers to mass percentage for solid-liquid mixing and solid-solid mixing, and refers to volume percentage for liquid-liquid mixing.
[0026] Unless otherwise specified, the percentage concentrations referred to in the present invention all refer to final concentrations, which refer to the percentage of the added component in the system after the addition of the component.
[0027] The temperature parameters in the present invention, if not specifically limited, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument.
[0028] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.
[0029] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.
[0030] Embodiment 1:
[0031] Alkali lignin was dissolved in a sodium hydroxide solution with a pH of 13 to obtain a lignin / sodium hydroxide solution with a concentration of 30 wt%. Ferrosilicon copolymer (polymerized by sodium silicate and ferrate at a molar ratio of 1:1.25) was added to the lignin / sodium hydroxide solution at a mass volume ratio of 1 g:20 mL and ultrasonically dispersed uniformly to obtain a suspension. N-dodecyl acrylamide (the amount added was 0.75 times the mass of lignin) and ammonium persulfate (the amount added was 0.45% of the mass of N-dodecyl acrylamide) were added to the suspension, stirred at 90°C for 5 hours, and then hydroquinone (the amount added was 0.2% of the mass of N-dodecyl acrylamide) was added and stirred for 5 hours. After the stirring was completed, it was allowed to stand for 45 minutes, and then filtered, and the obtained solid product was washed and dried to obtain product I. The obtained product I and an inorganic flame retardant (mixed by monoammonium phosphate, diammonium phosphate, and urea in a mass ratio of 1:1:1) were added to a 2wt% (triethoxysilyl) methane / ethanol solution in a mass volume ratio of 1g:4g:70mL and stirred at 300rpm for 2h. After the reaction was completed, the solid product was filtered and washed and dried to obtain the final product.
[0032] Embodiment 2:
[0033] Alkali lignin was dissolved in a sodium hydroxide solution with a pH of 12 to obtain a lignin / sodium hydroxide solution with a concentration of 10wt%. Ferrosilicon copolymer (polymerized by sodium silicate and ferrate at a molar ratio of 1:0.5) was added to the lignin / sodium hydroxide solution at a mass volume ratio of 1g:30mL and ultrasonically dispersed uniformly to obtain a suspension. N-hexadecyl acrylamide (the amount added was 0.5 times the mass of lignin) and potassium persulfate (the amount added was 0.2% of the mass of N-hexadecyl acrylamide) were added to the suspension, stirred at 70°C for 3h, and then resorcinol (the amount added was 0.1% of the mass of N-hexadecyl acrylamide) was added and stirred for 4h. After the stirring was completed, it was allowed to stand for 60min, and then filtered, and the obtained solid product was washed and dried to obtain product I. The obtained product I and an inorganic flame retardant (mixed by monoammonium phosphate, diammonium phosphate, and urea in a mass ratio of 1:1:1) were added to a 1wt% (triethoxysilyl) methanol / ethanol solution in a mass volume ratio of 1g:5g:100mL and stirred at a speed of 200rpm for 3h. After the reaction was completed, the solid product was filtered and washed and dried to obtain the final product.
[0034] Embodiment 3:
[0035] Alkali lignin was dissolved in a sodium hydroxide solution with a pH of 14 to obtain a lignin / sodium hydroxide solution with a concentration of 50 wt%. Ferrosilicon copolymer (polymerized by sodium silicate and ferrate in a molar ratio of 1:2) was added to the lignin / sodium hydroxide solution in a mass volume ratio of 1 g:10 mL and ultrasonically dispersed uniformly to obtain a suspension. N-phenylethyl acrylamide (the amount added was 1 times the mass of lignin) and sodium persulfate (the amount added was 0.7% of the mass of N-phenylethyl acrylamide) were added to the suspension, stirred at 50°C for 6 hours, and then catechol (the amount added was 0.3% of the mass of N-phenylethyl acrylamide) was added and stirred for 6 hours. After the stirring was completed, it was allowed to stand for 30 minutes, and then filtered, and the obtained solid product was washed and dried to obtain product I. The obtained product I and an inorganic flame retardant (mixed by monoammonium phosphate, diammonium phosphate, and urea in a mass ratio of 1:1:1) were added to a 3wt% bis(triethoxysilyl)ethane / ethanol solution in a mass volume ratio of 1g:3g:40mL and stirred at 400rpm for 1h. After the reaction was completed, the solid product was filtered and washed and dried to obtain the final product.
[0036] Embodiment 4:
[0037] Alkali lignin was dissolved in a sodium hydroxide solution with a pH of 13 to obtain a lignin / sodium hydroxide solution with a concentration of 40 wt%. Ferrosilicon copolymer (polymerized by sodium silicate and ferrate in a molar ratio of 1:1) was added to the lignin / sodium hydroxide solution in a mass volume ratio of 1 g: 20 mL and ultrasonically dispersed uniformly to obtain a suspension. N-tetradecyl acrylamide (the amount added was 0.9 times the mass of lignin) and azobisisobutyronitrile (the amount added was 0.4% of the mass of N-tetradecyl acrylamide) were added to the suspension, stirred at 60°C for 5 hours, and then hydroquinone (the amount added was 0.2% of the mass of N-tetradecyl acrylamide) was added and stirred for 5 hours. After the stirring was completed, it was allowed to stand for 40 minutes, and then filtered, and the obtained solid product was washed and dried to obtain product I. The obtained product I and an inorganic flame retardant (mixed by monoammonium phosphate, diammonium phosphate, and urea in a mass ratio of 1:1:1) were added to a 2wt% bis(triethoxysilyl)methane / ethanol solution in a mass volume ratio of 1g:4g:80mL and stirred at 400rpm for 2h. After the reaction was completed, the solid product was filtered and washed and dried to obtain the final product.
[0038] Embodiment 5:
[0039] Alkali lignin was dissolved in a sodium hydroxide solution with a pH of 13 to obtain a lignin / sodium hydroxide solution with a concentration of 20 wt%. Ferrosilicon copolymer (polymerized by sodium silicate and ferrate at a molar ratio of 1:1.4) was added to the lignin / sodium hydroxide solution at a mass volume ratio of 1 g:20 mL and ultrasonically dispersed uniformly to obtain a suspension. N, N-dihexyl acrylamide (the amount added was 0.6 times the mass of lignin) and ammonium persulfate (the amount added was 0.35% of the mass of N, N-dihexyl acrylamide) were added to the suspension, stirred at 90°C for 5 hours, and then hydroquinone (the amount added was 0.2% of the mass of N, N-dihexyl acrylamide) was added and stirred for 5 hours. After the stirring was completed, it was allowed to stand for 45 minutes, and then filtered, and the obtained solid product was washed and dried to obtain product I. The obtained product I and an inorganic flame retardant (mixed by monoammonium phosphate, diammonium phosphate, and urea in a mass ratio of 1:1:1) were added to a 2wt% bis(triethoxysilyl)methane / ethanol solution in a mass volume ratio of 1g:4g:60mL and stirred at 300rpm for 2h. After the reaction was completed, the solid product was filtered and washed and dried to obtain the final product.
[0040] Comparative Example 1:
[0041] Alkali lignin was dissolved in a sodium hydroxide solution with a pH of 13 to obtain a lignin / sodium hydroxide solution with a concentration of 30 wt%. N-dodecyl acrylamide (the amount added was 0.75 times the mass of lignin) and ammonium persulfate (the amount added was 0.45% of the mass of N-dodecyl acrylamide) were added to the lignin / sodium hydroxide solution, and the mixture was stirred at 90°C for 5 h, and then hydroquinone (the amount added was 0.2% of the mass of N-dodecyl acrylamide) was added and stirred for 5 h. After the stirring was completed, the mixture was allowed to stand for 45 min, and then filtered. The obtained solid product was washed and dried to obtain product I. The obtained product I and an inorganic flame retardant (mixed with monoammonium phosphate, diammonium phosphate, and urea in a mass ratio of 1:1:1) were added to a 2 wt% (triethoxysilyl) methane / ethanol solution in a mass volume ratio of 1 g:4 g:70 mL and stirred at a speed of 300 rpm for 2 h. After the reaction was completed, the mixture was filtered, and the obtained solid product was washed and dried to obtain the final product.
[0042] Comparative Example 2:
[0043] Alkali lignin was dissolved in a sodium hydroxide solution with a pH of 13 to obtain a lignin / sodium hydroxide solution with a concentration of 30 wt%. Ferrosilicon copolymer (polymerized by sodium silicate and ferrate at a molar ratio of 1:1.25) was added to the lignin / sodium hydroxide solution in a mass volume ratio of 1 g:20 mL and ultrasonically dispersed uniformly to obtain a suspension. N-dodecyl acrylamide (the amount added was 0.75 times the mass of lignin) and ammonium persulfate (the amount added was 0.45% of the mass of N-dodecyl acrylamide) were added to the suspension, stirred at 90°C for 5 hours, and then hydroquinone (the amount added was 0.2% of the mass of N-dodecyl acrylamide) was added and stirred for 5 hours. After the stirring was completed, it was allowed to stand for 45 minutes, and then filtered, and the obtained solid product was washed and dried to obtain the final product.
[0044] Comparative Example 3:
[0045] Alkali lignin and ferrosilicon copolymer (formed by polymerization of sodium silicate and ferrate at a molar ratio of 1:1.25) were mixed in the same amount as in Example 1 to obtain product I. The obtained product I and an inorganic flame retardant (formed by mixing monoammonium phosphate, diammonium phosphate, and urea at a mass ratio of 1:1:1) were added to a 2wt% (triethoxysilyl) methane / ethanol solution at a mass volume ratio of 1g:4g:70mL and stirred at a speed of 300rpm for 2h. After the reaction was completed, the solid product was filtered and washed and dried to obtain the final product.
[0046] Comparative Example 4:
[0047] Inorganic flame retardant: a final product is obtained by mixing monoammonium phosphate, diammonium phosphate and urea in a mass ratio of 1:1:1.
[0048] Test 1: Performance testing of different products
[0049] Before testing, the products of each embodiment and comparative embodiment were mixed uniformly with each raw material according to the formula in Table 1 to obtain a mixture. The obtained mixture was then extruded and granulated using a twin-screw extruder. Finally, the obtained granules were pressed in a mold using a flat vulcanizer to obtain a 10 mm long × 10 mm wide × 2 mm thick specimen.
[0050] Table 1 Spline formula
[0051]
[0052]
[0053] Subsequently, the performance of the samples obtained from the embodiments and comparative examples was tested, and the results are shown in Table 2.
[0054] Table 2 Spline performance of each embodiment
[0055] Group Tensile strength(MPa) Elongation at break (%) Water absorption (%) Flame retardant grade Thermal conductivity Complete degradation time (d) Example 1 35.4 17.6 2.8 V-0 1.5 25 Example 2 36.1 18.3 2.5 V-0 1.2 27 Example 3 35.7 17.8 2.4 V-0 1.4 23 Example 4 35.9 18.2 2.7 V-0 1.3 26 Example 5 35.8 18.0 2.6 V-0 1.4 24 Comparative Example 1 35.1 15.5 2.2 V-1 1.2 22 Comparative Example 2 34.8 17.1 2.6 V-2 0.8 26 Comparative Example 3 30.2 11.4 1.5 V-1 1.0 19 Comparative Example 4 23.4 6.9 0.8 HB 0.6 --
[0056] Note: The complete degradation time in the table refers to the degradation time of the flame retardant alone.
[0057] It can be seen from the results in Table 2 that the flame retardants of Examples 1 to 5 of the present invention have higher flame retardancy and mechanical properties than those of Comparative Examples 1 to 4. Although the addition of the polymer may increase the overall degradation time of the sample strip, it does not affect the final degradation effect.
[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A process for preparing a flame retardant, characterized in that: The preparation process comprises the following steps: Dissolving lignin in an alkaline solution with a pH value between 12 and 14 to obtain a lignin alkaline solution with a concentration of 10 to 50 wt%; adding ferrosilicon copolymer to the lignin alkaline solution in a mass volume ratio of 1 g: 10 to 30 mL and ultrasonically dispersing the copolymer to obtain a suspension; Add the functional monomer and the initiator to the suspension, stir and react at 30-120° C. for 3-6 hours, then add the crosslinking agent and continue stirring for 4-6 hours, let stand for 30-60 minutes after the stirring, then filter, wash and dry the obtained solid product to obtain product I; The obtained product I and the inorganic flame retardant are added to a 1-3 wt% silane coupling agent / ethanol solution according to a mass volume ratio of 1g: 3-5g: 40-100mL, and stirred at a speed of 200-400rpm for 1-3h. After the reaction is completed, the mixture is filtered, and the obtained solid product is washed and dried to obtain a final product.
2. The preparation process according to claim 1, characterized in that: The lignin is selected from one or more of alkali lignin, lignin sulfonate, rice husk lignin, and bamboo lignin.
3. The preparation process according to claim 1, characterized in that: The alkali is sodium hydroxide and / or potassium hydroxide.
4. The preparation process according to claim 1, characterized in that: The ferrosilicon copolymer is formed by polymerizing sodium silicate and ferrate in a molar ratio of 1:0.5-2.
5. The preparation process according to claim 1, characterized in that: The functional monomer is selected from one or a mixture of two or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, N-phenylethyl acrylamide, N-octyl propionamide, N-tetradecyl acrylamide, N,N-dioctyl acrylamide, N,N-dihexyl acrylamide, N,N-di-n-octyl acrylamide and N,N-di-n-dodecyl acrylamide; The added amount of the functional monomer is 0.5 to 1 times the mass of the lignin.
6. The preparation process according to claim 1, characterized in that: The initiator is selected from one of ammonium persulfate, potassium persulfate, sodium persulfate, azobisisobutyronitrile, azobisisoheptanenitrile, and azobisisobutyramidine hydrochloride; The added amount of the initiator is 0.2-0.7% of the mass of the functional monomer.
7. The preparation process according to claim 1, characterized in that: The cross-linking agent is selected from any one of hydroquinone, resorcinol and catechol; The added amount of the cross-linking agent is 0.1-0.3% of the mass of the functional monomer.
8. The preparation process according to claim 1, characterized in that: The inorganic flame retardant is selected from one or more of monoammonium phosphate, diammonium phosphate and urea.
9. The preparation process according to claim 1, characterized in that: The silane coupling agent is selected from one of bis(triethoxysilyl)methane, bis(triethoxysilyl)ethane, (triethoxysilyl)methanol and (triethoxysilyl)methane.
10. The flame retardant prepared according to the preparation process according to any one of claims 1 to 9.