Search

CN-121990862-A - Preparation method of disilane-based synergistically modified nano-silica particle coated ammonium perchlorate anti-moisture-absorption material

CN121990862ACN 121990862 ACN121990862 ACN 121990862ACN-121990862-A

Abstract

The invention relates to the technical field of AP modification, in particular to a preparation method of a silica modified by double silane synergic modification through wet coating ammonium perchlorate anti-moisture absorption material, which comprises the steps of carrying out two-step synergic modification on the silica through a long-chain alkyl silane modifier and a short-chain alkyl silane modifier, introducing an anti-self-aggregation regulator to inhibit silane self-aggregation, modifying the surface through long-chain silane, filling gaps modified by the long-chain silane through short-chain alkyl, preparing modified nano silica particles, and coating the modified nano silica particles on superfine AP particles through wet modification; the modified nano silicon dioxide particles have enough steric hindrance due to the three-dimensional structure of the surface and have better hydrophobic property, and the agglomeration of the modified nano silicon dioxide particles can be effectively prevented when the modified nano silicon dioxide particles are coated on the AP; the method is green and pollution-free, the process is simple, the comprehensive performance is easy to control through simple adjustment, the problem that the superfine AP particles produced in industry are easy to absorb moisture and agglomerate can be solved, and the application range of the superfine AP particles in novel high-energy propellants is widened.

Inventors

  • MA ZHENYE
  • JIANG TIAN
  • JIANG JIE

Assignees

  • 南京师范大学

Dates

Publication Date
20260508
Application Date
20260212
Priority Date
20260125

Claims (10)

  1. 1. The preparation method of the disilane-based synergistically modified nano-silica particle coated ammonium perchlorate anti-moisture absorption material is characterized by comprising the following steps of: (1) Uniformly dispersing nano silicon dioxide into ethanol, ethyl acetate, a PH regulator and deionized water, adding a long-chain silane coupling agent and an anti-self-polymerization regulator to carry out a first-step modification reaction, and then adding a short-chain silane coupling agent to carry out a second-step modification reaction to obtain modified nano silicon dioxide particles; (2) And (3) placing the modified nano-silica particles prepared in the step (1) into an organic solution for uniform dispersion, adding superfine AP particles, carrying out ultrasonic stirring, and removing the organic solution to obtain the ammonium perchlorate anti-moisture absorption material coated with the nano-silica particles based on the disilane synergistic modification.
  2. 2. The preparation method of the ammonium perchlorate moisture absorption preventing material based on the disilane synergistic modification nano-silica particles is characterized in that in the step (1), the modified nano-silica particles comprise, by mass, 1-10% of nano-silica, 30-50% of ethanol, 5-30% of ethyl acetate, 5-30% of pH regulator, 5-30% of deionized water, 1-10% of long-chain silane coupling agent, 1-10% of short-chain silane coupling agent and 0.1-5% of self-aggregation preventing regulator.
  3. 3. The preparation method of the disilane-based synergistically modified nano-silica particle-coated ammonium perchlorate anti-moisture absorption material according to claim 1, wherein in the step (1), the particle size of silica is 1-100 nm.
  4. 4. The preparation method of the ammonium perchlorate moisture absorption preventing material based on the disilane synergistic modified nano-silica particle coating according to claim 1, wherein in the step (1), the long-chain silane coupling agent is one or more of dodecyl trimethoxy silane, hexadecyl trimethoxy silane, n-octyl trimethoxy silane, methyl dodecyl dimethoxy silane, tridecyl fluorooctyl triethoxy silane, 1H, 2H, 2H-perfluoro octyl trimethoxy silane, 1H, 2H, 2H-perfluoro octyl triethoxy silane.
  5. 5. The preparation method of the ammonium perchlorate moisture absorption preventing material based on the co-modified nano-silica particles coated with the double-silane according to claim 1, wherein in the step (1), the short-chain silane coupling agent is one or more of gamma-aminopropyl triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, methacryloxysilane and gamma-glycidoxypropyl trimethoxysilane.
  6. 6. The preparation method of the ammonium perchlorate moisture absorption preventing material based on the disilane synergistic modified nano-silica particle coating is characterized in that in the step (1), the self-polymerization preventing and controlling agent is one or more of hexadecyl trimethyl ammonium bromide, sodium dodecyl sulfonate, polyvinylpyrrolidone, sodium hexametaphosphate, hydroxypropyl methyl cellulose and Tween 20, and the pH regulating agent is one or more of ammonia water, anhydrous acetic acid, dilute hydrochloric acid and sodium hydroxide.
  7. 7. The preparation method of the ammonium perchlorate moisture-proof material based on the disilane synergistic modification nano-silica particle coating is characterized in that in the step (1), the temperature of the first-step modification reaction is 40-80 ℃ and the time is 2-6 h, and the temperature of the second-step modification reaction is 20-60 ℃ and the time is 2-4 h.
  8. 8. The preparation method of the ammonium perchlorate anti-moisture absorption material based on the disilane synergistic modification nano-silica particles is characterized in that in the step (2), the mass ratio of the modified nano-silica particles to the superfine AP particles is 1:200-1:10, and the particle size of the superfine AP particles is 50 nm-50 μm.
  9. 9. The preparation method of the disilane-based synergistically modified nano-silica particle coated ammonium perchlorate anti-moisture absorption material according to claim 1, wherein in the step (2), the organic solvent is one or more of ethyl acetate, dichloromethane, ethanol, diethyl ether, isobutanol and methanol.
  10. 10. The preparation method of the ammonium perchlorate moisture-absorption-preventing material based on the disilane synergistic modification nano-silica particle coating is characterized in that in the step (2), the ultrasonic frequency is 40 kHz, the ultrasonic power is 300W, the ultrasonic time is 1-10 min, the stirring rotating speed is 100-1500 r/min, and the stirring time is 1-10 min.

Description

Preparation method of disilane-based synergistically modified nano-silica particle coated ammonium perchlorate anti-moisture-absorption material Technical Field The invention relates to the technical field of AP modification, in particular to a preparation method of a silica through wet coating ammonium perchlorate moisture absorption prevention material based on disilane synergistic modification. Background Ammonium Perchlorate (AP) is one of the most widely used oxidants of solid rocket propellants, and ultrafining is a method capable of directly improving the exothermic performance and the safety performance when applied to the propellants. The superfine AP has the advantages of high specific surface area, high bulk density and the like due to the characteristic of small particle size, has great prospect in the propellant, but the high specific surface area also ensures that the superfine AP is more easily limited by the problems of moisture absorption, agglomeration and the like in practical application, so that the moisture absorption prevention and agglomeration resistance of the superfine AP are required to be improved to widen the application scene of the superfine AP in the propellant. At present, a plurality of researches have been studied to solve the problem of easy moisture absorption and agglomeration of superfine AP, chinese patent CN119461252A proposes that a single silane coupling agent modifies nano silicon dioxide and then coats the nano silicon dioxide on superfine AP by a wet method, so that the moisture absorption resistance of the superfine AP can be remarkably improved, but the agglomeration resistance of the superfine AP needs to be further verified. Another patent CN110845285B uses polyacrylate to coat AP, and after the coated material is placed under 25 ℃ and 100% RH for 24 hours, the moisture absorption rate is tested, which is 78% lower than that of pure AP. In the aspect of composite materials, wu Guanjie and the like coat HTPB and TDI on the surface of AP through in-situ polymerization, and the moisture resistance and the packing density of the prepared composite particles are greatly improved. (Wu Guanjie, any Quan Bin, hu Chunbo, and the like.) the nano graphite and F2603 fluoropolymer are coated onto superfine AP in a synergistic way based on the powder propellant performance [ J ]. Energetic material, 2017, 25 (8): 627-632.) Yu of the AP pretreatment technology, the AP@nano-graphite@F2603 microcapsule energetic material is prepared, the hydrophobic performance of the material is greatly improved, and the researches of optimizing .（J. H. Yu, Y. Kou, L. Xiao, et al. Efficient construction of core/double-shelled structured AP@nano-graphite@F2603 energetic microcapsules with low sensitivity and hygroscopicity[J]. Nanoscale, 2025, 17(5): 2769-2781.） on the exothermic performance, the safety performance and the like also show that the surface modification and coating are effective ways for improving the moisture resistance of the superfine AP. Bis-silane co-modification techniques have received attention for their ability to combine the advantages of different functional groups. However, silanes tend to hydrolyze and self-polymerize to form clusters, resulting in non-uniformity of the coating. According to the invention, the hydrolysis rate of silane is regulated by introducing the anti-self-polymerization regulator, self-polymerization caused by different hydrolysis activities of different introduced silane coupling agents is prevented, and a hydrophobic layer with steric hindrance due to formation of a three-dimensional structure is constructed on the surface of nano silicon dioxide by utilizing the synergistic effect of the long-chain silane coupling agent containing long-chain alkyl and the short-chain silane coupling agent containing short-chain alkyl so as to coat modified superfine AP particles with sufficient anti-aggregation performance and larger hydrophobic performance. Disclosure of Invention The invention aims to provide a preparation method of an ammonium perchlorate moisture absorption preventing material coated with nano silicon dioxide particles based on disilane synergistic modification, which aims to solve the problems in the background technology. According to the method, silicon dioxide is subjected to two-step synergistic modification by a long-chain alkyl silane modifier and a short-chain alkyl silane modifier, and an anti-self-polymerization regulator is introduced to inhibit self-polymerization among silanes, so that modified nano silicon dioxide particles which are firstly grafted with long-chain alkyl and then filled with gaps by short-chain alkyl are obtained, and then the modified nano silicon dioxide particles are applied to superfine AP particles by wet modification. The modified superfine AP particles have better anti-caking property and anti-moisture absorption property. The method has simple process, low cost and high safety, can prevent the sup