Thermal decomposition mechanism of particulate core-shell KClO3-HMX composite energetic material

The thermal decomposition mechanism of a newly designed composite material KClO3-HMX (KC-HMX) is investigated by combined TG-DSC-FTIR technique and T/Jump in-situ thermolysis cell/FTIR (T/Jump FTIR) technique.It is shown that KC-HMX began to decompose at about 266°C without melting, and the fast stage of mass loss at the temperature range of 268.4~290.1°C is considered to be the result of the thermolysis and complex reactions of KClO3 and HMX with energy release of 1859 J.g, which exceeded that of pure HMX about 40%. It is also shown that CO, CO2, NO2 and H2O were the main gaseous products. The T/Jump FTIR analysis showed that the competing reactions of N-N and C-N bonds cleavage occurred in initial stage of HMX decomposition are greatly affected by KClO3. In contrast of pure HMX, there is no CH2O and HCN detected in its thermolysis products. In presence of electronegative oxygen radical produced by thermolysis of KClO3 oxidized CH2O and HCN through gas-phase reaction “(NO2+4O2) + (2N2O+5CH2O) → 5NO+3CO+2CO2+5H2O”, which is probably the dominating reaction, being immediately followed by the decomposition reaction of HMX.