Physical and thermal impact of lead free ballistic modifiers

Abstract

Preparation of solid propellants based on nitrocellulose was carried out. Modifications on the prepared propellants took place on the basis of environmental aspects. The effect of different ballistic modifiers (bismuth (III) citrate, bismuth sub nitrate and bismuth (III) oxide in comparison with lead oxide) on thermal decomposition behavior of nitrocellulose based propellants was studied. DTA and DSC thermal analysis were conducted to evaluate the performance of the modified propellants. Results from DTA and DSC were used to calculate the apparent activation energy. The relation between the obtained activation energy and the extent of conversion was investigated using DSC data treated with Friedman model. Thermal conductivity, bulk density and specific gravity were also measured to study the effect of burning rate modifier on physical properties of propellant. Results showed that the conventional propellant modifier lead oxide could be replaced by bismuth salts while maintaining the main thermal and physical properties of propellant without a significant shift in its thermal behavior.