Changes in the Calorimetric Value and Ignition Temperature of Composite Solid PropeIl:tnts During Ageing-A Note

Abstract. Calorimetric value and ignition temperature of carboxy terminated polybutadiene/ammonium perchlorate propellant decrease during accelerated ageing. The behaviour has been explained on account of binder loss and condensed phase reactions in the propellant matrix. 1. introduction Ageing brings about significant changes in the performance parameters of composite solid propellants: the changes in mechanical properties, thermal decomposition and burning rate have been examined earlier ’-I”. But as how the ageing brings about changes in the calorimetric value and initial ignition behaviour is not known for certain. Milera ” has observed that the calorimetric value of propellants aged for i-6 months at 65IOO”C does not change. Most of the earlier literature on ageing vis-a-vis ignition of the propellant is related to the safety aspects of the prdjiellant’“-‘“. In the present investigation, we have examined different kin of ignition behaviour which has a relevance to the initial. ignition temperature of the propellant and bears a direct consequence to our earlier ‘