Understanding aging in pentaerythritol tetranitrate
- Los Alamos National Laboratory
Pentaerythritol Tetranitrate (PETN) powder is commonly used in detonators because of its sensitivity and explosive power. PETN detonation is largely determined by the average PETN particle size. This is an issue for aging and storage of weapons because PETN has a relatively high vapor pressure and its average particle size changes due to thermal energy input from the environment. PETN aging is a well known problem although the mechanism is not well understood. It is important to understand PETN aging so that predictive models can be constructed that will benefit stockpile surveillance and lifetime extension programs. PETN particles are known to coarsen over time at relatively low temperatures. Particle coarsening requires mass redistribution since decomposition causes powders to become finer as PETN mass is lost. Two possible mechanisms for mass redistribution are vapor phase transfer via sublimation-redeposition and solid-state mass transfer through surface diffusion. In this work we have examined PETN powders us ing permeability, atomic force microscopy (AFM), and optical microscopy based particle analysis. The results of these measurements lead us to a suggested coarsening mechanism that we reproduce with rudimentary simulations. The physical mechanisms used in the simulations are then used to create an empirical model of the coarsening that may be used to make predictions of PETN aging. In the future we will be measuring the vapor pressures and other physical properties of our powders to be able to make predictions using simulations.
- Research Organization:
- Los Alamos National Laboratory (LANL)
- Sponsoring Organization:
- DOE
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 990308
- Report Number(s):
- LA-UR-09-03972; LA-UR-09-3972
- Country of Publication:
- United States
- Language:
- English
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