Analyses of the thermal characteristics and gaseous products of guanidine nitrate/basic copper nitrate mixtures using calorimetry with high resolution mass spectrometry

This work assessed the pyrolysis of a well-established gas generating agent consisting of a mixture of guanidine nitrate (GN) with basic copper nitrate (BCN), using thermogravimetry-differential scanning calorimetry in conjunction with high resolution mass spectrometry (TG/DSC/FIRMS). This instrumentation simultaneously determined mass changes and heat flow, and also permitted evaluation of evolved gases on an accurate mass basis. Fragmentation ratio correction was used to analyze the MS data acquired via electron ionization. GN/BCN mixtures were found to undergo pyrolysis to evolve H2O, N-2, NO center dot, CO2 and N2O. Using FIRMS, species having similar masses, such as CO2 and N2O, CO and N-2, and NH3 and OH center dot, were successfully distinguished. The thermal analysis data and the gas evolution results allowed a pyrolysis mechanism to be proposed. In this mechanism, a copper(II) complex obtained from the BCN catalytically decomposes NH3 generated from the GN to produce N-2 and H2O. The pyrolysis of a mixture of GN and BCN thus provides a synergistic effect that increases the heat and gas output.