The in uence of relative humidity on the degradation of a nitrocellulose-based propellant with ethyl centralite as stabilizer was investigated. For this kind of material, long term safe storage -maybe decades -is required and various relative humidity conditions can be found. The investigation of chemical integrity only based on accelerated ageing by heating is not su cient to make secure predictions of the degradation in real conditions. The propellant was aged in different conditions of relative humidity and temperature in order to evaluate the in uence of relative humidity on the stabilizer consumption and the consequent chemical integrity. The residual stabilizer was quanti ed by HPLC analyses. The degradation behavior at ambient temperature was predicted according to the linearized Arrhenius model. We observed a substantial difference in ethyl centralite consumption by comparing the values obtained for distinct humidity conditions. A possible explanation was proposed. Our results, allows one to propose an optimum range of relative humidity for long term storage.

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This paper presents experimental results for the double ended initiation of cylindrical, explosive charges. Bare cylindrical charges of PE4 (RDX/binder 88/12 %) were used with length to diameter ratios of 1/3.7 to 5.75/1 and masses of 0.25 to 0.45 kg. Pressure measurements were taken at distances of 1 to 3.5 m in the radial direction. It was found that it was possible to predict the peak overpressure in the radial direction using P=K′ M(L/D)1/3R−3. M is the mass of explosive, L the length of the explosive charge, D the diameter of the explosive charge, and R the distance from the charge. For PE4, K′=2251 kPa m3 kg−1 for all length to diameter ratios. The double ended initiation gives a peak overpressure 1.6 times that for single ended initiation. The impulse for double ended initiation was found to be the same as for single ended initiated charges.

PlSEM is a plastic explosive based on RDX, PETN and a nonexplosive binder, and is used in linear shaped charges for demolition purposes. Its experimentally obtained detonation parameters are presented in the present paper. The detonation velocity was measured for cylindrical charges of various diameters, with and without confinement. The detonation pressure and particle velocity were determined using an impedance window matching technique, and cylinder tests were used to obtain the parameters of the JWL equation of state of the detonation products. Detonation velocities from 7.75 to 8.05 km·s -1 were obtained for unconfined charges with diameters from 4 to 8 mm, and from 8.15 to 8.24 km·s -1 for charges with 25 mm diameter. The experimentally determined detonation pressure was found to be 24.6 GPa.