Influence of ageing on nitrocellulose thermal properties and hazard potential figures-of-merit : Major challenges for fluids transport property research in the next century
Thermal decomposition reactions in nitrocellulose, which is the basic component of homogeneous propellants, limit the safe use and safe storage time of propellants. Under certain conditions the decomposition may lead to the well-known phenomenon of self-ignition. The influence of accelerated ageing of a nitrocellulose propellant on the heat capacity, activation energy, pre-exponential factor, heat of decomposition, and hazard potential figures-of-merit is studied. The study is performed with differential scanning calorimetry and the thermal explosion theory. It is found that the activation energy, pre-exponential factor, and heat of decomposition decrease with ageing, while the heat capacity increases. That causes a decrease of the critical temperature, critical sample half-thickness, time-to-thermal runaway, and consequently an increase of thermal hazard potential.