Thermal Behaviour of AP-Based CMDB Propellants with Stabilizers

Stability test results and DT A studies indicate the superiority of molecular sieve (MS) over zirconium silicate (ZrSiO4) as the stabilizer for a composite modified double base (CMDB) system. Shelf life as computed from autoignition test results was 30 years for MS-based composition which is almost double the life of ZrSiO4, but approximately half the life of resorcinol-based composition which was used as a reference. Higher stabilizing effect of MS as compared to ZrSiO4 has been explained on the basis of the presence of channels and cavities in its structure, which makes it an effective adsorbent for decomposition catalysing species. Poor stabilization capability of m-dinitrobenzene as compared to resorcinol suggests the catalytic involvement of acidic decomposition products of nitrate esters in autodecomposition process of CMDB propellants. decomposition products of nitrate esters which further catalyse the autodecomposition process. These systems were evaluated with reference to resorcinol which is reported to be most effective in CMDB propellant3.5.9. The results obtained by Asthana and Singh for resorcinol-stabilized CMDB composition are included as reference'l. m-dinitrobenzene was also assessed as a stabilizer with reference to resorcinol. This study reports the results of stability tests. namely. Abcl heat test, methyl violet test, vacuum stability test, DT A, isothermal gravimetric analysis (IGA) and time-to-autoignition (T AI ) test .