Search

CN-118084590-B - Modified carbon nitride speed reducer and application thereof in solid propellant

CN118084590BCN 118084590 BCN118084590 BCN 118084590BCN-118084590-B

Abstract

The invention belongs to the technical field of solid propellants, and relates to a modified carbon nitride speed reducer and application thereof in the solid propellants, wherein the modified carbon nitride speed reducer is applied in a double-base solid propellant, and the modified carbon nitride speed reducer is applied in a butyl hydroxy solid propellant. According to the invention, the modified carbon nitride is obtained by mixing the carbon nitride and the fluorine-containing precursor and then carrying out high-temperature quenching treatment, the stability is good at normal temperature and normal pressure, and a large amount of energy can be released after the modified carbon nitride is burnt under pure oxygen condition, when the modified carbon nitride is used as a speed reducer in a solid propellant, the combustion speed and the pressure index of the propellant are reduced, the energy of the propellant is maintained and even improved, and meanwhile, the mechanical property of the propellant can be obviously improved.

Inventors

  • XU KANGZHEN
  • WAN CHONG
  • CHEN SUHANG
  • WANG CHEN
  • DONG SHUAI
  • LIU XINGLONG
  • ZHU YUQI

Assignees

  • 西北大学

Dates

Publication Date
20260512
Application Date
20240208

Claims (7)

  1. 1. The application of the modified carbon nitride speed reducer in the double-base solid propellant is characterized in that the preparation method of the modified carbon nitride speed reducer is as follows: S1, directly calcining melamine to obtain carbon nitride powder A; S2, mixing the powder A obtained in the step S1 with a fluorine-containing precursor according to the mass ratio of 100 (1-9), and sequentially carrying out drying, high-temperature quenching treatment and ball milling to obtain a modified carbon nitride speed reducer; the fluorine-containing precursor in the step S2 is polyvinylidene fluoride, perfluoropolyether or polytetrafluoroethylene.
  2. 2. The application of the modified carbon nitride speed reducer according to claim 1, wherein the mass of the modified carbon nitride speed reducer is 0.4% -1.2% of the total mass of the double-base solid propellant, the burning speed of the double-base solid propellant is 6.96-9.16 mm/s, and the pressure index of the double-base solid propellant is 0.03-0.07.
  3. 3. The application of the modified carbon nitride speed reducer in the butyl hydroxy solid propellant is characterized in that the preparation method of the modified carbon nitride speed reducer is as follows: S1, directly calcining melamine to obtain carbon nitride powder A; S2, mixing the powder A obtained in the step S1 with a fluorine-containing precursor according to the mass ratio of 100 (1-9), and sequentially carrying out drying, high-temperature quenching treatment and ball milling to obtain a modified carbon nitride speed reducer; the fluorine-containing precursor in the step S2 is polyvinylidene fluoride, perfluoropolyether or polytetrafluoroethylene.
  4. 4. The method according to claim 3, wherein the mass of the modified carbon nitride speed reducer is 0.5% of the total mass of the butylhydroxyl solid propellant, and the pressure index of the butylhydroxyl solid propellant is 0.29.
  5. 5. The method according to claim 1 or 3, wherein the calcination conditions in step S1 are 550 ℃ temperature, 4h calcination time, and -1 min at a temperature increase rate of 2.5 ℃.
  6. 6. The application of claim 5, wherein the high-temperature quenching treatment condition in the step S2 is that the temperature is 300-550 ℃, the time is 2-4 h, and the temperature rising rate is 2.5 ℃ and -1 ~10.0℃•min -1 .
  7. 7. The use according to claim 5, wherein the particle size of the modified carbon nitride accelerator in step S2 is 1 μm to 2 μm.

Description

Modified carbon nitride speed reducer and application thereof in solid propellant Technical Field The invention belongs to the field of application of solid propellants, and relates to a modified carbon nitride speed reducer and application thereof in the solid propellants. Background The solid propellant is a material for a power source of a solid rocket engine, plays an important role in the development of missile and aerospace technology, and can be generally divided into a double-base propellant, a composite propellant, a modified double-base propellant and a NEPE propellant. Along with the development of weapon equipment to the directions of miniaturization, intellectualization, remote striking, accurate guidance and the like, tactics and technical indexes of weapon equipment such as rocket endurance engines, missile and space vehicle attitude and orbit control engines, gas generators, rocket-shooting rocket range-increasing engines and the like are more and more severe, and the requirements for high-energy low-combustion-speed propellants (low thrust under high pressure, long endurance and no reduction of specific impulse) are more and more. The conventional mode for reducing the burning rate of the propellant is mainly started from the aspects of reducing the energy of a system through decomposition heat absorption, inhibiting the combustion reaction of important components of the propellant and the like. In the most widely used HTPB/AP/Al (hydroxyl-terminated polybutadiene/ammonium perchlorate/aluminum powder) composite solid propellant, the burning rate is reduced mainly by inhibiting AP thermal decomposition, wherein ammonium oxalate ((NH 4)2C2O4) has the advantages of good effect, small dosage and the like, the speed reducing effect is most obvious (Shi Liangwei, wu Yaming, lv Long. HTPB propellant is researched by quaternary ammonium salt high-efficiency speed reducer [ J ]. Solid rocket technology, 2023,46 (6): 842-847.). In the double-base solid propellant, the initial decomposition temperature of an energy-containing component in the propellant is influenced mainly by melting or decomposition heat absorption, so that the burning rate and pressure index of the propellant are changed, and the added speed reducer mainly comprises copolyformaldehyde (POM), sucrose Octaacetate (SOA), polymethyl methacrylate (PMMA) and the like (Chen Yong, zhao Fengqi, li Hui, and the like; the current status of solid propellant speed reducing agent research and development trend [ J ]. Explosives and gases, 2021,44 (5): 567-577.); if the modified double-base propellant contains AP, the combustion speed can be reduced by adding a speed reducing agent such as urea, melamine, lithium fluoride, quaternary ammonium salt and the like and inhibiting the thermal decomposition of oxide Ammonium Perchlorate (AP) (Zhang Guohui, zhao Fengqi, xu Siyu and the like; the technical research progress of realizing the low combustion speed regulation of double-base propellant [ J ]. The technical report of weapon equipment engineering, 2021,42 (12): 16-22 ]), but in the modified double-base propellant containing a large amount of high-energy solid materials, the speed reducing agent can obviously reduce the system energy and specific impulse due to the fact that the speed reducing agent does not contain energy per se, meanwhile, the addition amount and the speed reducing effect of the speed reducing agent are limited (Yang Libo, influence of the composite speed reducing agent on the combustion performance of the low-combustion-speed propellant [ J ]. The explosive theory, 2013,36 (6): 70-73.) and the mechanical property of the propellant are also negatively influenced. Graphite carbon nitride (g-C 3N4) is taken as a novel typical high-nitrogen polymer, has a planar two-dimensional lamellar structure similar to graphene, can be obtained by calcining nitrogen-rich precursors such as cyanamide, urea, thiourea, melamine, dicyandiamide and the like, has short and simple preparation process flow, high synthesis yield and low cost (Ma D,etal.Research development on graphitic carbon nitride and enhanced catalytic activity on ammonium perchlorate[J].RSC Advances,2021,11,5729.),, and has good chemical stability and thermal stability (the thermal decomposition temperature is 650 ℃) at normal temperature and normal pressure. In addition, g-C 3N4 is used as a high-nitrogen material, the nitrogen content of the high-nitrogen material is up to 60.9%, and the high-nitrogen material can be combusted under pure oxygen to release a large amount of energy, so that the high-nitrogen material is an excellent combustion speed catalyst for the composite solid propellant. Therefore, it is of great importance to develop a speed reducer that can reduce the burning rate of the propellant while maintaining or even increasing the energy and specific impact of the propellant. Disclosure of Invention Aiming at the technical problems that the existing speed reducer