engleski

Thermal characterisation of stable and unstable nitrocellulose propellant

Thermal decomposition reaction of nitrocellulose limits safe and reliable service life of propellants. Under certain conditions it can lead to the well-known phenomena of self-ignition. It is therefore of great concern to predict whether or not a propellant will ignite under given conditions. However, the ageing of propellants is not only a safety problem. It also causes decrease of relevant propellants’ properties (decrease of nitrocellulose molar mass, decrease of stabiliser content, decrease of a specimen mass, change of mechanical and ballistic performances, etc.). Thus, the ageing should be quantified by measuring both the changes of these relevant properties and hazard potential as a function of time and temperature. Some thermal properties of a stable and an unstable nitrocellulose propellants were studied in this paper in order to detect and to quantify changes observed. The thermal characterisation was carried out by using differential scanning calorimetry and thermogravimetric analysis. It was found out that some of thermal properties and thermo-kinetic constant of stable (non-aged) nitrocellulose propellant, and the same propellant aged up to 9 days at 100 oC, differ significantly. At the same time, some parameters do not change significantly the ageing period studied.

nitrocelulose; thermal stability

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