Insensitivity aspects of NC bonded and DNDA plasticizer containing gun propellants

摘要

New type of semi nitramine gun propellants (NT-GP) containing crystalline energetics as RDX or FOX 7 and DNDA as plasticizer bonded by nitrocellulose (NC) show improved performance with regard to thermal sensitivity, shaped chargejet impact, force and barrel erosion. Further they show a low temperature coefficient in gun firing. The thermal sensitivity is assessed by measurements of heat generation rate and heat generation between 60℃ and 90℃ with microcalorimeter and mass loss between 70℃ and 90℃, autoignition temperature and adiabatic self heating determined by an ARC™ (Accelerating Rate Calorimeter). The data of six propellants of new type are compared and discussed with two conventional ones: the double base gun propellant L5460 (= JA2) and the triple base GP Q5560 (MRCA). The data of mass loss and heat generation rate are modelled and Ar-rhenius parameters have been obtained. The often found strong increase in mass loss after the consumption of active stabilizers is not shown by the new type propellants. The autoignition temperature of the new type propellants is with 185 to 220℃ at 5℃/min heat rate higher than the typical values of common NC-propellants with 170 to 175℃. Results of a shaped charge jet impact are presented as well as data for adiabatic flame temperature and barrel erosion.