Curve for PETN

Luminosity curves for PETN of loading d 1.60 detonated in vacuum are represented nere. The left curve was photographed, using optical filters, with transmission maxima at A=6870, while for the right one A was 4510. In this type of curve, the intensities of the peaks with maximum deflection during the deton interval were used for the evaluation of temperature of detonation 

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Results of Paterson s work show that the receptor (PETN) is considerably overprimed by the NG based expl, and slightly under-primed by the TNT based expl. The. reflected wave is in each case a rarefaction, very weak with the TNT explosive. The condition for no reflected wave is that the primer C-J point lie on the receptor RH curve. The condition for a stable wave in the receptor is that the receptor CJ point lie on the primer RH curve while the condition for exactly balanced priming is that the two CJ points coincide. The last condition is satisfied at every section in a single expl cartridge Fig 2 shows also, for comparison, the transmitted RH curve for nonreactive waves. The properties of such waves transmitted by the same two primers are summarized by Paterson in the table, but this part is omitted bv Dunkle and by us... 

In ProgrRept July-Sept 1949 are given photographs of luminosity curves for deton of PETN of loading d 1.40 in air as recorded on a sweep trace of 10 20 microsec duration In ProgrRept Apr-June 1950 is given the following table of relative luminosity of "detonation peak for three expls in pellet form ... 

There are also given curves of relationship betw temps of deton and densities for PETN, Tetryl TNT, based on the values obtd by P. Caldirola, JChemPhys 14, 738-40(1946), as compared with the values obtd at BurMines (See Fig 1 of the progr rept)... 

Cook et al (Ref 6, pp 44-57) found that velocities in the ideal detonation of gases are much.less sensitive to the initial density (designated by him as pp than in condensed explosives. Curves given in Fig 2.2 and Fig 3-3, p 47 (our figs 1 8t 2) show relationships D vs p for HBX Tritonal are nonlinear and D vs d(diameter) have some anomalous depressions. This was observed in 1954, but was withheld from publication until 1957, when Berger et al (Ref 5) observed in France the same phenomenon in their. D vs p curves for mixtures of PETN and Al, p = 0.92 ... 

Deceleration curves for low density expl compacts (Taken from Ref 43a) are shown in Fig 27. Downward curvature of these plots indicates accelerating decompn. Note that the curves show the expected sensitivity order of PETN)... 

Figure 5.30 DSC curves for (a) PETN, (b) BPO and (c) 2,4-DNT. Heating rate, 2°C min" atmosphere, air sample container, sealed stainless steel (15 ul)...

Ammonium picrate is of a very high order of stability. In the lOO C heat test, 0.1 percent is lost in the first 48 hours and 0.1 percent in the second 48 hours. No explosions occur in 100 hours. In the 130"C heat test there is no acidity or explosion in 300 minutes. The vacuum stability test at 100°C produced 0.2 cubic centimeters of gas in 40 hours, at 120°C, 0.4 cubic centimeters of gas are produced, and at 150°C, 0.4 cubic centimeters of gas are produced. The material has been found to withstand storage at ordinary temperatures for a period of twenty years with no evidence of deterioration, and at 50°C for more than five years without marked deterioration. Moisture increases ammonium picrate s reactivity with metals such as lead, potassium, copper, and iron. The compounds produced are extremely sensitive. This reactivity requires that all projectiles loaded with this material have contact areas covered with acid proof paint. At 100°C ammonium picrate is compatible with TNT or black powder but undergoes reactions with nitroglycerin, nitrocellulose, PETN, or tetryl. Figure 8-42 shows the DTA curve for ammonium picrate. 

The PETN Detonation Pressure, P (also called the CJ Pressure), is shown as a function of packing density in Table 7 and in Fig 4. Note that the measured P values in Fig 4 lie quite close to the theoretical curve developed by Lee Homig (Ref 72), which is based on a Wilkin s type equation of state (see Vol 4, D294-L) with a Grueneisen ratio, r, for the detonation products, that is solely a function of specific volume. Shea et al obtained an effective T = 8.077 p-12.288 (Ref 74)... 

Recently Romanov and Sten gach (Ref 89) found that discharge energies for 50% explns of PETN Increased with PETN particle size, packing density, water content, circuit inductance, and a decrease in ambient temp. The discharge energy-interelect rode distance curve... 

The curves logw vs time are given on pp 176-77 for AN, EDNA PETN. This method is not applicable to expls in which.weight loss is the result solely of decomposition and not merely of vaporization or both vaporization and decomposition. It cannot be used for TNT because at the temperatures at which. it. could be applied vaporization and decomposition take place simultaneously... 

The isothermal method for such expls as PETN, RDX, NG and Tetryl is complicated by autocatalysis to such an extent that one cannot determine the intrinsic (pure explosive) decompn rate from the logw vs t curves and their change with temperature. Hence, the results obtd by the adiabatic(sensitivity) methods may be more reliable from this viewpoint (Ref 8, p 177)... 

Lafitte (Ref 2), vel of deton generally increases with the diam of cartridge up to a maximum value, above which the vel remains constant. This is true for PA, RDX and for AN/Tetryl mixts contg more than 10% Tetryl, but for some other expls, such as PETN and Tetryl, the curve of deton vel vs cartridge diam increases at first, passes thru a maximum, then decreases and, after passing thtu a minimum, rises again... 

T. Urbanski, Influence of Non-Explosive liquids on the Detonation Rate of Solid Explosives , ArchProcesouSpalania 3 (2), 117—32 (1972) CA 78, 99944 (1973) [The author discusses the effect on the deton rate of adding w to PETN, RDX, p-Nitrotoluene or TNT in concns of from 5 to 40%. He reports that at low w concns the deton rate is minimized. As the w content increases the deton rate curve passes thru a maximum to reach a second minimum at the higher ( V 40%) level of w concn. The author concludes that the increase in deton rate can be attributed to three factors, the existence of a covolume, a phlegmatizing factor, and the result of mixing of two components, at least one of which is expl] 9) T.V. Ferris, Expansion of Methanol-Air Mixtures at Above Atmospheric Conditions , LossPrevn 8,15—19 (1974) CA 82, 45989 (1975) [Upper flammability limits were detd for various mixts of methanol with air, or a 30/70 02—N2 mixt with and without w. A rise of 12 vol % in the flammability limit above the nominal value of 36 vol % methanol in w-free air mixts is reported in the presence of liq w]... 

Application of Eq. 19 to the /7-HMX isotherm from simulations leads to the Us-Up curve shown in Fig. 11, where negative curvature in the simulation results is clearly evident (filled circles). While such behavior would be anomalous for metals, it is actually expected for pressures below about one GPa in the case of polyatomic molecular crystals, due to complicated molecular packings and intramolecular flexibility, and has in fact been reported for the high explosives pentaerythritol tetranitrate (PETN) where careful studies were performed for low levels of compression [77], By contrast, the experimental results for /3-HMX in the Us-Up plane do not exhibit significant curvature due to lack of data at pressures below about one Gpa [78], Thus, estimates of isothermal sound speeds, and hence isothermal bulk moduli, based on... 

The European Commission for the Standardization of Testing of Explosive Materials ) recalculated the results for a 10-ml test sample, using a calibration curve established by Kurbalinga and Kondrikov, as modified by Ahrens the reported value refers to the mixture of PETN... 

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