Hexanitrostilbene (HNS), is added to trinitrotoluene (TNT), in order to improve the grain structure of cast munitions. The
formation and composition of the nucleant material has been investigated by thermal methods using mixtures of HNS and TNT,
with composition in the range 0.5%, the normal casting level, to 50% w/w HNS to TNT. These were cycled between ambient and
upper temperatures in the range 160 to 235°C. Endotherms in the DSC traces, due to nucleant decomposition, have been observed
in situ without the need for separation and purification. DSC enthalpy measurements, before and after thermal decomposition,
were used to determine the composition of separated nucleant. Nucleant regeneration after decomposition, was investigated
by thermal methods. Nucleant could not be recrystallised from solvents. Results have been interpreted on the basis of the
formation of a, solid solution of TNT in HNS, rather than a complex of formula TNT2HNS.