Development of a Mechanical Properties Kinetic Model for ageing of a UK Plastic Bonded Explosive

摘要

The safety and performance of high explosives are inextricably linked to their engineering characteristics. A simple predictive model for a UK Polymer Bonded eXplosive (namely EDC37) has been developed from thermally aged data that can account for ageing behaviour of some engineering properties. The model was developed assuming the direct link between molecular weight (Mn) of the nitrocellulose in the binder and flexure strength. From simple Ekenstam and Arrhenius equations, kinetic parameters have been derived for flexure stress. The mean rate constant for real-time aged EDC37 is compared to that predicted from the thermally aged data. The result demonstrates a good correlation. The predicted rate constant for the real-time aged data has been used in the Ekenstam-like equation to predict flexure strength at any age. The starting conditions for the model are taken from the mean and spread of unaged flexure stress data. The average model represents real-time aged data well and shows the rate of degradation for this data is low. Recommendations are given for future work, including the need to address flexure stress data scatter, determine a mechanistic cause for degradation and increase the number of data in the real-time aged data set for EDC37.