NAl (at) SCA (at) fluorine-containing polyether composite particle and preparation method thereof
By introducing a silane coupling agent onto the surface of aluminum powder and covalently bonding it with fluorinated polyether, the problem of poor interfacial bonding between aluminum powder and fluorinated polymers was solved, resulting in higher combustion efficiency and stability, and expanding the functionality of the composite material.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HARBIN INST OF TECH
- Filing Date
- 2026-01-15
- Publication Date
- 2026-04-21
AI Technical Summary
In existing technologies, aluminum powder and fluoropolymers have poor interfacial bonding, traditional fluoropolymers have limited potential for functional expansion, and their stability is insufficient at high temperatures, affecting the combustion efficiency and stability of solid propellants.
Using silane coupling agent as a bonding agent, Si-O-Al bonds are generated on the surface of aluminum powder through hydrolysis and condensation reaction, and then linked with fluorinated polyether through ring-opening, addition polymerization or click reaction to form nAl@SCA@fluorinated polyether composite particles, thereby improving the interfacial bonding stability and functionality.
It enhances the interfacial bonding stability between aluminum powder and fluorinated polymers, inhibits combustion agglomeration, improves combustion efficiency and environmental stability, and expands the functional applications of composite materials.
Smart Images
Figure CN121895101A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a fluorinated polyether composite particle and its preparation method, belonging to the field of nanomaterial modification and composite material technology. Background Technology
[0002] Metal fuels are an important component of solid propellants. Aluminum powder is often added to solid propellants due to its advantages such as high heat of combustion and high energy density to improve the propulsion performance of solid rocket motors. However, in application, it has been found that aluminum powder is prone to oxidation and combustion agglomeration, which leads to a decrease in propellant specific impulse and two-phase flow loss. Therefore, improving the combustion efficiency of aluminum powder is of great significance to the development of propellants.
[0003] Surface modification of Al powder with fluorinated polymers is an efficient modification method. Most studies have shown that fluorinated polymers promote the ignition and combustion of aluminum powder in energetic materials such as thermite, propellants, and explosives. At the same time, they can act as a protective layer for Al powder, giving it excellent environmental stability. Although fluorinated polymers have shown certain advantages in modifying Al powder, existing research still has some limitations. In current systems, fluorinated polymers are mostly combined with Al powder through physical coating or blending, resulting in poor interfacial bonding and limited improvement in combustion performance. At the same time, the types of fluorinated polymers currently used are limited, with most employing PVDF, PTFE, P(VDF-HFP), etc., making it difficult to adjust their chemical structures and limiting the functional expansion of composite materials.
[0004] Therefore, optimizing the interfacial bonding between Al and fluorinated polymers has attracted widespread attention. Currently, most efforts are made to optimize the interfacial bonding performance by establishing non-covalent bond mechanisms, such as introducing oleic acid, polydopamine, and fluorinated carboxylic acids as bonding agents. Although these methods have improved the compatibility between Al and fluorinated polymers to some extent, they are mainly based on physical adsorption or coordination. They are prone to desorption under solvent treatment or high-temperature environments, have poor long-term stability, and have limited effect on improving energy output.
[0005] Therefore, introducing suitable bonding agents to improve the interfacial bonding stability between Al and fluorinated polymers is an important challenge. At the same time, increasing the designability of fluorinated polymers to expand the functional applications of composite materials is also an important direction for future development.
[0006] Silane coupling agents contain two groups with different chemical properties, which can bond with different substances respectively. They are often used to improve the interfacial properties of composite materials and enhance the interfacial bonding performance between inorganic and organic materials. Branched fluorinated polyethers are fluorinated polymers with simple synthesis methods and highly designable chemical structures, and have extremely strong functional expansion capabilities. Based on the above viewpoints, using silane coupling agents as bonding agents, one end can be firmly bonded to the nAl surface through hydrolysis and condensation reactions, while the other end can be connected to fluorinated polyethers with special end groups through ring-opening, addition polymerization, click reactions, etc. The formation of covalent bonds can improve the interfacial bonding stability between nAl and fluorinated polymers. In addition, the introduction of fluorinated components can promote the reactivity of nAl, which is expected to solve the above problems. Summary of the Invention
[0007] To address the problems of poor interfacial bonding of nAl fluoropolymers and limited potential for functional expansion of traditional fluoropolymers in the prior art, this invention proposes an nAl@SCA@fluorinated polyether composite particle and its preparation method.
[0008] The technical solution adopted by the present invention to solve the above problems is as follows: The structural formula of the branched fluorinated polyether of the nAl@SCA@fluorinated polyether composite particles of the present invention is: , Where m and n are both positive integers.
[0009] The steps of the method for preparing nAl@SCA@fluorinated polyether composite particles according to the present invention include: Step 1: Stir and disperse nAl in solvent A for 10-40 min, and then sonicate for 10-40 min to obtain an nAl dispersion. Step 2: Add silane coupling agent to nAl dispersion and stir vigorously at 25°C for 12-36 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@SCA modified particles. Step 3: Dissolve the fluorinated polyether in organic solvent B in a four-necked flask to obtain a transparent solution. Add catalyst / initiator C under nitrogen and stir at room temperature for 1 h. At the same time, ultrasonically disperse the nAl@SCA modified particles in solvent B at room temperature for 10-30 min to obtain an nAl@SCA modified particle dispersion. Step 4: Slowly add the nAl@SCA modified particle dispersion dropwise into the flask at 10-80℃. After the addition is complete, continue stirring at 10-80℃ for 4-24 h. Collect the powder by centrifugation, wash it three times with ethanol, and then collect it by centrifugation again. Finally, vacuum dry it at 30-100℃ for 12 h to obtain nAl@SCA@FPE composite particles.
[0010] Furthermore, branched fluorinated polyethers have a variety of end-group structures, which can be used to coat nAl@SCA modified particles through end-group chemical reactions.
[0011] Furthermore, the mass ratio of nAl, SCA, and FPE is 1:(0.02~4):(0.01~1).
[0012] Furthermore, the silane coupling agent is one or more of 3-glycidyloxypropyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, 3-isocyanopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(isobutenoyloxy)propyltrimethoxysilane, and trichlorovinylsilane.
[0013] Furthermore, solvent A in step 1 is one or more of dichloromethane, ethyl acetate, ethanol, cyclohexane, n-butanol, and isopropanol.
[0014] Furthermore, solvent B in step 3 is one or more of dichloromethane, dichloroethane, chloroform, ethyl acetate, dimethyl carbonate, methylformamide, dimethylacetamide, N-methylpyrrolidone, and acetone.
[0015] Furthermore, the catalyst / initiator C in step 3 is one or more of the following: boron trifluoride tetrahydrofuran complex, stannous octoate, dibutyltin dilaurate, triphenylbismuth, triethylenediamine, benzoyl peroxide, di-tert-butyl peroxide, azobisisobutyronitrile, triethylamine, and m-phenylenediamine.
[0016] The beneficial effects of this invention are: 1. The silane coupling agent provided in this application can improve the interfacial bonding stability between nAl and fluorinated polyether FPE. One end is hydrolyzed to generate Si-OH, which condenses with the hydroxyl groups on the nAl surface to form Si-O-Al, which is firmly bonded to the nAl surface. The other end can be connected to the fluorinated polyether with special end groups through ring-opening, addition polymerization, click and other reactions.
[0017] 2. The fluorinated polyether structure provided in this invention application has the advantages of simple synthesis and strong chemical structure designability. By introducing different end groups and different side chains, it can be efficiently combined on the nAl surface and endowed with other potential properties, thus expanding the functional applications of composite particles.
[0018] 3. Surface modification of nAl powder with fluorinated polyether can effectively inhibit the combustion agglomeration of nAl, improve the combustion efficiency of nAl, and at the same time improve the environmental stability of nAl.
[0019] 4. The preparation method provided in this invention application is simple and efficient, and the raw materials are all common chemical reagents, which have the potential for large-scale production. Attached Figure Description
[0020] Figure 1 This is the FTIR image of the Al@KH560@HFPE composite particles prepared in Example 1; Figure 2 The XPS spectrum of the Al@KH560@HFPE composite particles prepared in Example 1; Figure 3SEM image of the Al@KH560@HFPE composite particles prepared in Example 2; Figure 4 This is a high-speed photograph of the combustion of the Al@KH560@HFPE composite particles prepared in Example 2.
[0021] Example Example 1 (1) 1 g nAl was stirred and dispersed in 40 ml ethyl acetate for 30 min, and then ultrasonically dispersed for 30 min to obtain an nAl dispersion; (2) Add 0.1 g of 3-glycidyloxypropyltrimethoxysilane (KH560) to the nAl dispersion and stir vigorously at 25°C for 12 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@KH560 modified particles.
[0022] (3) 0.2 g of hydroxyl-terminated fluorinated polyether (HFPE) was dissolved in 30 ml of ethyl acetate in a four-necked flask to obtain a transparent solution. The catalyst boron trifluoride tetrahydrofuran complex was added under nitrogen and stirred at room temperature for 1 h. At the same time, the nAl@KH560 modified particles were ultrasonically dispersed in ethyl acetate for 15 min at room temperature to obtain a dispersion of nAl@KH560 modified particles. (4) The nAl@KH560 modified particle dispersion was slowly added dropwise into the flask at 25℃. After the addition was completed, the mixture was stirred at 25℃ for 6 h. The powder was collected by centrifugation, washed three times with ethanol, and then collected by centrifugation again. Finally, the powder was vacuum dried at 100℃ for 12 h to obtain nAl@KH560@HFPE composite particles.
[0023] Example 2 (1) 1 g nAl was stirred and dispersed in 40 ml ethanol for 20 min, and then ultrasonically dispersed for 30 min to obtain an nAl dispersion. (2) Add 2 g of 3-glycidyloxypropyltrimethoxysilane (KH560) to the nAl dispersion and stir vigorously at 25°C for 14 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@KH560 modified particles.
[0024] (3) 0.2 g of hydroxyl-terminated fluorinated polyether (HFPE) was dissolved in 30 ml of chloroform in a four-necked flask to obtain a transparent solution. Stannous octoate catalyst was added under nitrogen and stirred at room temperature for 1 h. At the same time, nAl@KH560 modified particles were ultrasonically dispersed in chloroform for 30 min at room temperature to obtain nAl@KH560 modified particle dispersion. (4) The nAl@KH560 modified particle dispersion was slowly added dropwise into the flask at 25℃. After the addition was completed, the mixture was stirred at 25℃ for 12 h. The powder was collected by centrifugation, washed three times with ethanol, and then collected by centrifugation again. Finally, the powder was dried under vacuum at 100℃ for 12 h to obtain nAl@KH560@HFPE composite particles.
[0025] Example 3 (1) 1 g nAl was stirred and dispersed in 30 ml ethanol for 20 min, and then ultrasonically dispersed for 30 min to obtain an nAl dispersion. (2) Add 1 g of 3-aminopropyltriethoxysilane (KH550) to the nAl dispersion and stir vigorously at 25 °C for 12 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@KH550 modified particles.
[0026] (3) A transparent solution was prepared by dissolving 0.1 g of epoxy-terminated fluorinated polyether (EFPE) in 30 ml of dichloroethane in a four-necked flask. Stannous octoate catalyst was added under nitrogen atmosphere and stirred at room temperature for 1 h. At the same time, nAl@KH550 modified particles were ultrasonically dispersed in dichloroethane for 20 min at room temperature to obtain a dispersion of nAl@KH550 modified particles. (4) The nAl@KH550 modified particle dispersion was slowly added dropwise into the flask. After the addition was complete, the mixture was stirred at 25 °C for 16 h. The powder was collected by centrifugation, washed three times with ethanol, and then collected by centrifugation again. Finally, the powder was dried under vacuum at 80 °C for 12 h to obtain nAl@KH550@EFPE composite particles.
[0027] Table 1. Hot water corrosion resistance of nAl, nAl@KH550, and nAl@KH550@EFPE
[0028] Example 4 (1) 0.5 g nAl was stirred and dispersed in 30 ml isopropanol for 30 min, and then ultrasonically dispersed for 30 min to obtain an nAl dispersion. (2) Add 0.2 g of 3-(isobutenoyloxy)propyltrimethoxysilane (KH570) to the nAl dispersion and stir vigorously at 25°C for 16 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@KH570 modified particles.
[0029] (3) Dissolve 0.05 g of vinyl-terminated fluorinated polyether (VFPE) in 30 ml of dimethyl carbonate in a four-necked flask to obtain a transparent solution. Add the initiator azobisisobutyronitrile in nitrogen and stir at room temperature for 1 h. At the same time, ultrasonically disperse nAl@KH570 modified particles in dimethyl carbonate at room temperature for 20 min to obtain nAl@KH570 modified particle dispersion. (4) The nAl@KH570 modified particle dispersion was slowly added dropwise into the flask at 65℃. After the addition was completed, the mixture was stirred at 65℃ for 4 h. The powder was collected by centrifugation, washed three times with ethanol, and then collected by centrifugation again. Finally, the powder was vacuum dried at 80℃ for 12 h to obtain nAl@KH570@VFPE composite particles.
[0030] Example 5 (1) 1 g nAl was stirred and dispersed in 30 ml ethyl acetate for 20 min, and then ultrasonically dispersed for 20 min to obtain an nAl dispersion; (2) Add 0.2 g of 3-isocyanate-propyltrimethoxysilane (IPTS) to the nAl dispersion and stir vigorously at 25 °C for 12 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@IPTS modified particles.
[0031] (3) 0.2 g of hydroxyl-terminated fluorinated polyether (HFPE) was dissolved in 30 ml of dimethylformamide in a four-necked flask to obtain a transparent solution. Dibutyltin dilaurate catalyst was added under nitrogen atmosphere and stirred at room temperature for 1 h. At the same time, nAl@IPTS modified particles were ultrasonically dispersed in dimethylformamide at room temperature for 30 min to obtain nAl@IPTS modified particle dispersion. (4) The nAl@IPTS modified particle dispersion was slowly added dropwise into the flask at 45℃. After the addition was completed, the mixture was stirred at 45℃ for 10 h. The powder was collected by centrifugation, washed three times with ethanol, and then collected by centrifugation again. Finally, the powder was dried under vacuum at 60℃ for 12 h to obtain nAl@IPTS@HFPE composite particles.
[0032] Example 6 (1) 1 g nAl was stirred and dispersed in 30 ml cyclohexane for 20 min, and then ultrasonically dispersed for 20 min to obtain an nAl dispersion; (2) Add 0.1 g (3-mercaptopropyl)trimethoxysilane (KH590) to the nAl dispersion and stir vigorously at 25 °C for 18 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@KH590 modified particles.
[0033] (3) 0.1 g of vinyl-terminated fluorinated polyether (VFPE) was dissolved in 30 ml of dimethylformamide in a four-necked flask to obtain a transparent solution. Triethylamine catalyst was added under nitrogen and stirred at room temperature for 1 h. At the same time, nAl@KH590 modified particles were ultrasonically dispersed in dimethylformamide at room temperature for 30 min to obtain nAl@KH590 modified particle dispersion. (4) The nAl@KH590 modified particle dispersion was slowly added dropwise into the flask at 25℃. After the addition was completed, the mixture was stirred at 25℃ for 12 h. The powder was collected by centrifugation, washed three times with ethanol, and then collected by centrifugation again. Finally, the powder was vacuum dried at 60℃ for 12 h to obtain nAl@KH590@VFPE composite particles.
[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.
Claims
1. An nAl@SCA@fluorinated polyether composite particle, characterized in that, The structural formula of branched fluorinated polyether is: ， Where m and n are both positive integers.
2. A method for preparing nAl@SCA@fluorinated polyether composite particles, characterized in that, The specific steps include: Step 1: Stir and disperse nAl in solvent A for 10-40 min, and then sonicate for 10-40 min to obtain an nAl dispersion. Step 2: Add silane coupling agent to nAl dispersion and stir vigorously at 25°C for 12-36 h. Collect the powder by centrifugation and wash it three times with ethanol. Collect it by centrifugation again and finally dry it under vacuum to obtain nAl@SCA modified particles. Step 3: Dissolve the fluorinated polyether in organic solvent B in a four-necked flask to obtain a transparent solution. Add catalyst / initiator C under nitrogen and stir at room temperature for 1 h. At the same time, ultrasonically disperse the nAl@SCA modified particles in solvent B at room temperature for 10-30 min to obtain an nAl@SCA modified particle dispersion. Step 4: Slowly add the nAl@SCA modified particle dispersion dropwise into the flask at 10-80℃. After the addition is complete, continue stirring at 10-80℃ for 4-24 h. Collect the powder by centrifugation, wash it three times with ethanol, and then collect it by centrifugation again. Finally, vacuum dry it at 30-100℃ for 12 h to obtain nAl@SCA@FPE composite particles.
3. The method for preparing nAl@SCA@fluorinated polyether composite particles according to claim 2, characterized in that, Branched fluorinated polyethers have a variety of end-group structures, and nAl@SCA modified particles are coated through end-group chemical reactions.
4. The method for preparing nAl@SCA@fluorinated polyether composite particles according to claim 2, characterized in that, The mass ratio of nAl, SCA, and FPE is 1:(0.02~4):(0.01~1).
5. The method for preparing nAl@SCA@fluorinated polyether composite particles according to claim 2, characterized in that, The silane coupling agent is one or more of 3-glycidyloxypropyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, 3-isocyanopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(isobutenoyloxy)propyltrimethoxysilane, and trichlorovinylsilane.
6. The method for preparing nAl@SCA@fluorinated polyether composite particles according to claim 2, characterized in that, Solvent A in step 1 is one or more of dichloromethane, ethyl acetate, ethanol, cyclohexane, n-butanol, and isopropanol.
7. The method for preparing nAl@SCA@fluorinated polyether composite particles according to claim 2, characterized in that, Solvent B in step 3 is one or more of dichloromethane, dichloroethane, chloroform, ethyl acetate, dimethyl carbonate, methylformamide, dimethylacetamide, N-methylpyrrolidone, and acetone.
8. The method for preparing nAl@SCA@fluorinated polyether composite particles according to claim 2, characterized in that, The catalyst / initiator C in step 3 is one or more of the following: boron trifluoride tetrahydrofuran complex, stannous octoate, dibutyltin dilaurate, triphenylbismuth, triethylenediamine, benzoyl peroxide, di-tert-butyl peroxide, azobisisobutyronitrile, triethylamine, and m-phenylenediamine.