Dynamic Mechanical Properties of Candidate Lova and Nitrocellulose Base Gun Propellants after up to 18 Months of Accelerated (High Temperature) Aging

摘要

Several candidate low vulnerability (LOVA) propellants and several nitrocellulose (NC) base (single, double, and triple) propellants have been subjected to accelerated aging at 65.5 C and mechanical properties measured. The propellants were investigated in compression after 0, 1, 2, 3, 6, 12, and 18 months. Measurements were made at -45 C and 23 C at a strain rate of approximately 10/sec. Little or no change in the compressive strengths of the candidate LOVA propellants was observed. In contrast, significant decreases in the compressive strengths of double and triple base NC propellants were found. The candidate LOVA propellants thus are more thermally stable than the NC base propellants for the conditions of these studies. Possible processes which account for the observed changes and the relationship of these changes to combustion and ballistic properties are discussed. The compressive strengths of all unaged candidate LOVA propellants investigated are significantly lower than the compressive strengths of unaged NC single, double, and triple base propellants at -45 C and most NC propellants at 23 C.