CN-121975253-A - NAL@fluorosilane/fluoropolymer composite film and preparation method thereof

CN121975253ACN 121975253 ACN121975253 ACN 121975253ACN-121975253-A

Abstract

A nAL@fluorosilane/fluoropolymer composite membrane and a preparation method thereof relate to a composite membrane and a preparation method thereof. The invention aims to solve the problems of poor compatibility of nAL and a fluoropolymer and insufficient existence of a bonding agent in the prior art. The preparation method comprises the steps of ultrasonically dispersing NAL in a solvent, adding fluorosilane for surface modification, stirring for a certain time, collecting powder to obtain NAL@fluorosilane modified particles, dissolving the fluorosilane modified particles in the solvent according to a proportion to prepare a fluoropolymer solution, adding the NAL@fluorosilane modified particles into the fluoropolymer solution, ultrasonically stirring for a certain time, pouring into a mold, and vacuum drying to obtain the NAL@fluorosilane/fluoropolymer composite film. The invention belongs to the technical field of composite materials.

Inventors

BAI YONGPING
LI XUEJIN
MENG LINGHUI
HE JINMEI
ZHU XIAONAN
DENG CHAO
PENG HAORAN
YANG QIFAN

Assignees

哈尔滨工业大学
无锡海特新材料研究院有限公司

Dates

Publication Date: 20260505
Application Date: 20260115

Claims (8)

1. A nal@fluorosilane/fluoropolymer composite film, characterized in that the composite film is prepared by a solvent evaporation method using soluble fluoropolymers and nal@fluorosilane modified particles.
2. The preparation method of the nAL@fluorosilane/fluoropolymer composite film is characterized by comprising the following specific steps: Step 1, stirring and dispersing nAL in a solvent A for 5-30 min, and performing ultrasonic dispersion for 5-30 min to prepare nAL dispersion; Step 2, adding fluorosilane into the nAL dispersion liquid, stirring for 4-20 hours at room temperature, centrifugally collecting powder, washing with ethanol for three times, centrifugally collecting, and finally drying in vacuum to obtain nAL@fluorosilane modified particles; Step 3, dissolving the fluoropolymer in the organic solvent B to prepare a fluoropolymer solution, and then adding the nAL@fluorosilane modified particles into the fluoropolymer solution, and stirring and dispersing by ultrasonic for 5-30 min until the mixture is uniform; and 4, pouring the dispersion liquid into a polytetrafluoroethylene mould, and finally, vacuum-drying at 25-85 ℃ for 2-24 h, and demoulding to obtain the nAL@fluorosilane/fluoropolymer composite film.
3. The method for preparing a compound film of nal@fluorosilane/fluoropolymer according to claim 2, wherein the selected fluoropolymers are all soluble in organic solvents and formed into films by a solvent evaporation method.
4. The preparation method of the nAL@fluorosilane/fluoropolymer composite film according to claim 2, wherein the mass ratio of nAL to fluorosilane to fluoropolymer is 1 (0.01-3): 0.5-5.
5. A process for preparing a composite film of nAL@fluorosilane/fluoropolymer according to claim 2, the fluorosilane is 3, 3-trifluoropropyl trimethoxysilane, 1H, 2H-nonafluorohexyl trimethoxysilane, 1H, 2H-perfluorooctyl triethoxysilane one or more of 1H, 2H-perfluorodecyl trichlorosilane and 1H, 2H-perfluorododecyl trichlorosilane.
6. The method for preparing the nal@fluorosilane/fluoropolymer composite film according to claim 2, wherein the fluoropolymer is one or more of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer and soluble fluorine-containing polyurethane.
7. The method for preparing the naci@fluorosilane/fluoropolymer composite film according to claim 2, wherein the solvent a is one or more of dichloromethane, ethyl acetate, methanol, ethanol, cyclohexane, n-hexane and isopropanol.
8. The method for preparing a naci@fluorosilane/fluoropolymer composite film according to claim 2, wherein the solvent B is one or more of ethyl acetate, acetone, tetrahydrofuran, dimethyl sulfoxide, dimethylformamide, dimethylacetamide and N-methylpyrrolidone.

Description

NAL@fluorosilane/fluoropolymer composite film and preparation method thereof Technical Field The invention relates to a composite membrane and a preparation method thereof, and belongs to the technical field of composite materials. Background Aluminum powder is widely used as metal fuel in energetic materials such as propellant, initiating explosive device and the like because of the advantages of high volume energy density, low cost and abundant reserves. However, aluminum powder is easy to oxidize to form an Al 2O3 layer, and the high-melting-point boiling point property of the aluminum powder leads to incomplete combustion, so that the energy output is reduced, and the significance of improving the combustion efficiency of the aluminum powder is great. A great deal of researches show that the aluminum powder and the fluorine-containing polymer (such as PVDF, THV, PTFE and the like) are compounded by means of blending or coating, so that the combustion efficiency can be improved by breaking an oxidation layer and generating a mechanism of low-boiling-point aluminum fluoride, and meanwhile, the aluminum powder is used as a protective layer to improve the environmental stability of the aluminum powder. The fluorine polymer and the nAL are prepared into the energetic film with specific shape and size by methods of solvent volatilization, hot press forming, electrostatic spinning, 3D printing and the like, is a key technical path for realizing miniaturization of the energetic material and controllable energy release, and is expected to be applied to the fields of miniature detonating, flexible ignition elements, corrosion-resistant energetic coatings, micro-thrust systems and the like. However, the compatibility between the nals and the fluoropolymers is poor, the combustion performance is often lower than expected, and the practical application of the nals is severely restricted, so that a strategy for optimizing an interface structure is widely focused, and the reactivity of the nals is improved by increasing the contact area and reducing the mass and heat transfer distance. KH-570, oleic acid, polydopamine, tannic acid, micromolecular fluorine-containing carboxylic acid and the like which are introduced at present are used as bonding agents to optimize an interface structure, although the compatibility of nAL and a fluoropolymer is improved, the bonding agents are combined with the surface of Al mostly through physical adsorption or coordination, the long-term stability is poor, the phenomenon of easy desorption exists when a solvent exists, a lasting interface optimization effect cannot be established, and meanwhile, part of bonding agents lack fluorine-containing groups, so that the effect is poor in energy output. The introduction of suitable bonding agents both solves the compatibility of the nals with the fluoropolymers and improves the reactivity of the nals is an important challenge. From the above point of view, the use of fluorine-containing silane as a bonding agent, surface modification of nAL, which can form Al-O-Si covalent bonds on the aluminum surface, form firm combination, the fluoroalkyl end can be connected with the fluoropolymer through the bonding action of C-F.F-C and C-F.H-C, therefore, the compatibility of the nAL and the fluoropolymer is improved, the interface combination is optimized, in addition, the fluorosilane can be used as an additional oxidant and a protective layer to promote the combustion of the nAL and improve the environmental stability, and the technical route is expected to solve the problems. Disclosure of Invention The invention aims to solve the problems of poor compatibility of nAL and a fluoropolymer and insufficient existence of a bonding agent in the prior art, and further provides a nAL@fluorosilane/fluoropolymer composite film and a preparation method thereof. The technical scheme adopted by the invention for solving the problems is that the nAL@fluorosilane/fluoropolymer composite film is prepared by using soluble fluoropolymers and nAL@fluorosilane modified particles through a solvent volatilization method. The preparation method of the nAL@fluorosilane/fluoropolymer composite film comprises the following steps: Step 1, stirring and dispersing nAL in a solvent A for 5-30 min, and performing ultrasonic dispersion for 5-30 min to prepare nAL dispersion; Step 2, adding fluorosilane into the nAL dispersion liquid, stirring for 4-20 hours at room temperature, centrifugally collecting powder, washing with ethanol for three times, centrifugally collecting, and finally drying in vacuum to obtain nAL@fluorosilane modified particles; Step 3, dissolving the fluoropolymer in the organic solvent B to prepare a fluoropolymer solution, and then adding the nAL@fluorosilane modified particles into the fluoropolymer solution, and stirring and dispersing by ultrasonic for 5-30 min until the mixture is uniform; and 4, pouring the dispersion liquid into a polytetrafluoroethyl