Effects Of Nano-aluminum On The Thermal Decomposition Kinetics Of HMX

The catalyst is the primary means of improving the thermal decomposition characteristics and blasting performance of explosive, and catalytic activity and selectivity of the nano-catalyst has a great advantage over traditional catalyst, nano-metal catalyst is used as an important component of solid propellant, who changes the thermal decomposition characteristics and blasting performance of solid propellant significantly. HMX is a very good elemental explosive who has detonation performance, it is widely used in solid propellant, propellant and mixing explosive. Aluminum as a major component of propellant, its content, particle size and other physical factors have a direct effect on the thermal decomposition characteristics and blasting performance of HMX, so instead of using micron aluminum powder, nano-aluminum powder has a very good prospect.This article first study the thermal decomposition kinetics and thermal safety aspects of HMX in depth discussion, Then by comparing the effect of micron and nano aluminum on thermal decomposition kinetics of HMX, focuses on the nano-aluminum thermal decomposition kinetics of HMX.By analyzing the non-isothermal TG-DSC of HMX and HMX+Al, HMX is a typical "Melt Decomposition" type substance, decomposition and melting at the same time, reaction accelerating is caused by the phase change, leading to self-heating and autocatalytic of HMX obviously. Micron aluminum has a minimal thermal decomposition effect on HMX, and nano-aluminum better catalysis of HMX on thermal decomposition. When the mass fraction of nano-aluminum is 40%, the catalytic effect is the best. From four aspects analyzes the thermal decomposition mechanism of nano-aluminum catalytic on HMX.Using Popescu method infers thermal decomposition mechanism function, the thermal decomposition reaction mechanism, function integral form and differential form, and kinetic equations of exothermic decomposition reaction of HMX and HMX+40%Al. By studying kinetic compensation effect between ln A and E, found HMX and HMX+40%Al in different conditions(different heating rates) and different methods obtained ln A and E has very good kinetic compensation effect.Calculating values of the thermal explosion critical temperature Tb and self accelerating decomposition temperature TSADT of HMX and HMX+40%Al, Tb and TSADT of HMX+40%Al has decreased compared with HMX. Calculating the thermodynamic parameters activation entropy ΔS≠, activation enthalpy ΔH≠ and activation free energy ΔG≠ of HMX and HMX+40%Al, values of thermodynamic parameters of activation entropy ΔS≠ and activation enthalpy ΔH≠of HMX+40%Al has decreased comparing HMX, while the free energy of activation ΔG≠ did not change significantly.