Advances in polyNIMMO composite gun propellants

Efforts to develop very high energy tank gun propellants based on tradition al double or triple base propellant technology have often failed to deliver the low vulnerability required in Insensitive Munitions. One strand of the United Kingdom's formulation research programme has focused on the alterna tive technology of composite propellants. A range of composite LOVA propell ants based on the energetic binder poly-NIMMO in combination with various f illers and plasticisers has been examined. Assessment of their vulnerabilit y in the UK Small Scale Shaped Charge Attack test has shown correlations li nked both to the choice of filler and to the volume percentage of finer pre sent. Through a fuller understanding of the factors involved it has been sh own to be possible to formulate propellants with an impetus of up to 1300 k J/kg which still show a low response to shaped charge attack. This and prev ious studies have also identified the effect of grain geometry and web size on vulnerability. Since these parameters are dictated by ballistic conside rations a thorough understanding of the ballistic behaviour of this new cla ss of materials is particularly important. Vulnerability and ballistic cons iderations are presented and discussed.