Effect of particle size on energetic properties of Hexogen has been studied. To have a comprehensive picture, a wide range of particle size from 126 μm to 55 nm obtained by processing Hexogen with different techniques has been studied. Using sol-gel method, Hexogen materials with nanometer size particles have been prepared with induced defects like porosity. Chemical structure of processed materials with reduced particle size is found to be similar to that of raw material but these materials were having more uniform morphology with regular shaped particles. Kinetic parameters derived from thermal analysis indicated increase in activation energy with decrease in particle size, however, increase in rate constant suggested faster decomposition and higher energy release rate in these materials. Increase in detonation velocity of these materials supported observations noted in kinetic parameters study. Impact sensitivity was found to be decreased with decrease in particle size except for sol-gel processed samples. Though, activation energy in sol-gel processed samples was found to be increasing, impact test studies on these materials showed significant increase in sensitivity even though the particle size is reduced. This indicates that decomposition mechanism on impact in these samples is significantly affected by the defects like porosity.
energetic materials, hexogen, ultrafine particles, thermal decomposition, kinetics