The Combustion of Nitric Ester-Based Propellants: Ballistic Modification by Lead Compounds

Abstract

Many lead compounds bring about important changes in the flame temperature and gas composition near the burning surface of nitric esters and, in the case of solid compositions, seem to affect the initial degradation, giving more carbonaceous products on the surface. Temperatures near the surface, and rates of burning, in the low pressure range, of almost all compositions gelled with cellulose nitrate or acetate are increased considerably by the introduction of lead compounds, which not only activate the surface carbon but also appear to promote its formation. Chemical analysis of the dark zone suggests that the increased temperatures may be associated with enhanced reduction of nitric oxide in the primary reaction zone. A study of the influence of additives has led lo a possible explanation of the burning rate/ pressure relationship ( termed “ platonisation” ) characteristic of nitric ester compositions which contain lead.