Study On Formulations And Performances Of A New Kind Of Strong Flash Detonation Agent

Flash detonation bombs are widely studied as a powerful anti-riot bomb,however,it can not meet its strong flash and detonation effects.To improve its flash and detonation damage effects on the target,this paper designed a new type of flash detonation agent on the basis of researching the formula of strong flash detonation agent.The formulation of the flash detonation agent to solve the shortage of the existing flash detonation bombs.On the basis of studying the action principle of flash detonation agent,factors affecting the effect of flash and detonation and the principle of component selection were studied,the formulation of strong flash detonation agent and the effect of combustion heat were obtained by oxygen balance design and theoretical calculation,and the theoretical simulation study of binder was studied by molecular dynamics method,and then the influence of preparation solvent and temperature was studied.The molding powder of the strong flash detonation agent was prepared by ultrasonic assisted solvent evaporation method,and its properties were tested and reasons were analyzed.Main results are shown as follows:（1）According to the principle of component selection of flash detonation agent,both ammonium perchlorate（AP）with high oxygen content and gas production and copper oxide（CuO）with accelerated combustion speed were selected as oxidants,magnesium aluminum alloy powder（Mg/Al）which can enhance the flash ability and combustion heat of flash detonation agent was selected as combustibles fluorine-polymer(F₂₆₀₂)with good heat resistance and high density was used as binder,a new kind of strong flash detonation agent formulation focusing on flash effect was designed to achieve the flash and detonation effect of pyrotechnic powder.The formula of flash detonation agent was obtained by oxygen balance design and theoretical calculation:m（CuO）/m（NH₄Cl O₄）/m（Mg/Al）/m(F₂₆₀₂)=32.93/20.00/43.07/4.00.By calculation,the heat of combustion is 12.135k J/g,the combustion temperature is 2908.44℃,the specific volume is 249.09ml/g,and the solid residue rate is 0.77g/g.It is theoretically analyzed that the designed formula is feasible and can satisfy the flashing requirements.（2）The binding energy(E_bind),cohesive energy density（CED）,radial distribution function（RDF）and mechanical properties of polyethylene glycol（PEG）,ethylene vinyl acetate copolymer（EVA）,vinylidene fluoride and hexafluoropropylene copolymer(F₂₆₀₂)and phenol-formaldehyde resin（PF）binder system were simulated by molecular dynamics.Simulation results show that the E_bind of EVA system is the largest and the bonding effect is the best,but the mechanical properties are general;There is little difference between CED and intermolecular interaction force under different binder systems;F₂₆₀₂ system has the best mechanical properties,therefore,F₂₆₀₂ is the best binder of flash detonation agent.By calculating the binding energy of the binder and the solvent,it is concluded that ethyl acetate is the best preparation solvent and by comparing the area of the displacement produced by the thermal motion of the binder over time at different temperatures,that is,the mean square displacement,the best preparation temperature under the F₂₆₀₂ system is 60℃.The flash detonation agent modeling powder was prepared by the ultrasonic-assisted solvent evaporation method.Preparation process is safer and simpler,and its yield is higher.（3）Performances test of the flash detonation agent were carried out:both its electrostatic spark sensitivity and impact sensitivity are 0%;The friction sensitivity is higher than 96%;The flame sensitivity is lower,the ignition height is 2.33cm;5s explosion temperature（398°C）is slightly lower than the AP’s 5s explosion temperature（435°C）,and has good thermal sensitivity performance;The thermal decomposition peak and thermal explosion critical temperature of flash detonation agent are 576.45K and 580.35K,respectively,and the activation energy is201.05k J/mol,indicating that it is thermodynamically stable,and flash detonation agent Gibbs free energy（ΔG）greater than 0,indicating that under normal environment no chemical reaction will occur spontaneously in storage;The outgassing amounts of the flash detonation agent vacuum stability test are 0.18 ml/g,0.17 ml/g,0.18 ml/g,and the outgassing amounts are all less than 1.8ml/g.The net increase and outgassing of the reaction are all less than 3ml,which indicates that the vacuum stability is qualified and the internal compatibility is good;The combustion calorific value（11.835k J/g）measured by the experiment is lower than the theoretical value（12.135k J/g）,which is consistent with the theoretical calculation;When the charge of the flash detonation bomb is 60g,the charge density is 1.41g/cm~3,the luminous intensity at 6m from the explosion center is 6.68′10~7cd,which can cause flash blindness for more than 10s;When the charge of the flash detonation bomb is 60g,the charge density is1.41g/cm~3,the sound pressure value at 6m is 177.6d B,the resulting sound pressure level is26.9%higher than the current sound pressure level of 140d B（6m from the explosion center）,causing serious brain damage to the human body,resulting in temporary deafness or permanent damage to both ears;Accelerated aging storage test results predict that the flash detonation agent has a storage period of more than 13 years.