Closed-Vessel and Thermal Studies on Triple-Base Gun Propellants Containing CL-20

This study was undertaken to see the effect of the replacement of picrite by 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) (5, 10, and 15%) in triple-base gun propellants. Experimental results of a closed-vessel test at a loading density of 0.2 g/cm 3 indicate improvement in energetics of the CL-20-incorporated compositions. The force-constant values obtained were 1046, 1071, and 1095 J/g for 5, 10, and 15% CL-20-based formulations, compared with 1028 J/g for conventional picrite composition as the control. Similar trends were observed for linear burning-rate coefficient β 1 values. The selected energetic plasticizers N-(n-butyl)-N-(2-nitroxyethyl) nitramine (Bu-NENA) and bis-2,2 dinitro propyl formal/acetal (BDNPF/A) were also evaluated for their effectiveness in CL-20-containing gun-propellant compositions. Thermal analysis was carried out using differential scanning calorimeter and thermogravimetric analyzer. Replacement of picrite by CL-20 resulted in an increase in AH values (by differential scanning calorimeter) compared with that of control composition. Weight-loss data (from thermogravimetric analyzer) showed a similar trend. The CL-20-based compositions were found relatively more sensitive to friction stimuli (12-17 kg) compared with control composition (19.2 kg).