Performance and Sensitivity of Explosives

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126

Propellants, Explosives, Pyrotechnics 25, 126±132 (2000)

Performance and Sensitivity of Explosives Hans-Heinrich Licht Institut Franco Allemand de Recherches de Saint Louis, Deutsch-FranzoÈsisches Forschungsinstitut Saint Louis, (ISL), Postfach 1260, D-79574 Weil am Rhein (Germany)

Leistung und Emp®ndlichkeit von Explosivstoffen Meûergebnisse aus Tests zur Leistungs- und Emp®ndlichkeitsbeschreibung von Explosivstoffen wurden ± nach einer Normierung ± zu einer einzigen Leistungs- bzw. Sicherheits-Kennzahl fuÈr den jeweiligen Explosivstoff zusammengefaût. Das erlaubte eine Bewertung von Reinstoffen und speziellen Formulierungen im Hinblick darauf, wie weit die jeweilige Leistung des Explosivstoffs in einem ausgewogenen VerhaÈltnis zu seiner Emp®ndlichkeit steht. Bei einer graphischen Darstellung ergibt sich eine imaginaÈre Grenzlinie, was bedeutet, daû eine hohe Leistung mit einer erhoÈhten Emp®ndlichkeit parallel laÈuft und daû unemp®ndliche Sprengstoffe keine Spitzen-Leistung erbringen. Da dieses aus der Praxis der Ladungsherstellung gelaÈu®ge Ergebnis theoretisch nicht zu begruÈnden ist, sollte es auch Ausnahmen geben, also Explosivstoffe, die zumindest in ihrer Tendenz dem idealen Explosivstoff (mit hoher Leistung und hoher Sicherheit) nahe kommen, was durch Beispiele belegt wird.

Performance et sensibilite d'explosifs Les reÂsultats expeÂrimentaux de tests de performance et de sensibilite d'explosifs ont eÂte regroupeÂs ± apreÁs normalisation ± en une seule caracteÂristique de performance ainsi que de seÂcurite pour chaque explosif. Ceci permet d'eÂvaluer des composeÂs purs et des formulations speÂciales et de deÂterminer dans quelle mesure les performances de l'explosif sont en accord avec sa sensibiliteÂ. Un graphique met en eÂvidence une limite imaginaire signi®ant qu'une performance eÂleveÂe s'accompagne d'une sensibilite eÂleveÂe et que des explosifs insensibles ne donnent pas de performances maximales. Etant donne que ce reÂsultat ± trouve freÂquemment en pratique lors de la fabrication des charges ± ne peut eÃtre justi®e theÂoriquement, on peut imaginer qu'il y a aussi des exceptions, donc des explosifs qui tendent aÁ se rapprocher de l'explosif ideÂal (aÁ haute performance et haute seÂcuriteÂ), comme en teÂmoignent des exemples.

Summary

element composition, oxygen balanced compounds and energetic materials with metal admixture. All these explosives were investigated with respect to their performance and their sensitivity and stability, respectively. The ®rst and common description of the explosive performance is the detonation velocity D (measured at a desirably high charge density). This is not suf®cient as resulted by our own research on light-element explosives (ANQ, TAGN)(1), which exhibited besides attractive D values only low ballistic performance not predicted by model calculations. So as a p second base is applied the Gurney energy 2EG . For a more profound analysis we recommend the brisance of an explosive which can be quanti®ed by the depth (or the volume) of the denting from a detonation on a steel plate, the Plate Dent Test. The security data have to describe very differing properties. Shock sensitivity and thermal stability are preferred here, because the data are well accessible and only small sample amounts are needed. As a third term the detonability is obtained from the gap test which needs a more extensive investigation. Such data are available only for a part of the considered compounds and are reserved for the more detailed aspect of this subject.

Experimental data from several performance and sensitivity tests have been combined after normalization to de®ne a single performance and a security characteristic term, respectively. This allows to evaluate pure compounds and special formulations with regard to a well balanced ratio of performance and sensitivity. A graph shows an imaginary border line what has to be interpreted in the sense that ± in the praxis of explosive charges ± high performance is accompanied by an enhanced sensitivity and that an insensitive explosive will not exhibit a top performance. As this result cannot be proved by theory one should imagine that there are also exceptions, i.e. explosives which approach the ideal high explosive (with high performance and high security) what is exempli®ed.

1. Introduction Performance and sensitivity, often used in order to characterize energetic materials, are not precise terms. They have multiple aspects and they are quanti®ed by strongly differing test procedures. The description of an explosive will be the more complete the larger is the data basis which such an analysis is relied on. It is tried here to connect the performance and sensitivity data from ISL experiments to a single but complete explosive description. The representation proposed here can cover the desirable total aspect only to some extent as (for good reasons) exclusively own data from well de®ned tests are applied. So the valuation of explosives is based on only two or in a more profound consideration on three tests, each. This investigation is based on the ISL data collection published here which does not only take into account standard explosives but also high explosives with uncommon # WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000

2. The Coherence of Performance and Sensitivity Although there seems to exist a coherence between performance and sensitivity (we give a lot of examples), the more brisant explosive being also the more sensitive one, there is no fundamental law that the gain in performance has to be paid with a loss in security. This can be veri®ed by a few considerations: An explosive single crystal is not detonable 0721-3115/00/0306 ± 000126 $17.50‡:50=0

Propellants, Explosives, Pyrotechnics 25, 126±132 (2000)

in principle, but it carries the performance when it comes to a detonation at any way. The second example is even more familiar: TNT (cast) is like the single crystal a relatively homogeneous system and so it is detonable only with dif®culties in contrast to the pressed TNT which can be applied as a booster. But both have the same detonation velocity.

Performance and Sensitivity of Explosives

127

depends on a lot of parameters and can be treated as a constant only with certain restrictions. Similar are the relations for the security data. So the experimental conditions on which the results and their interpretation are based on, are described at ®rst.

3.1 Performance Data Determination 3.1.1 Detonation Velocity D

3. Experimental To obtain comparable data, the experimental conditions have to be de®ned precisely. Especially the Gurney constant Table 1. Performance Characteristics: Detonation Velocity Explosive

HN=HMX-65=35 HM=HN=TAGN-45=40=15 HMX=HN-70=30 HMX RDX=HN-55=45 HMX=ETN-65=35 ANQ RDX TeNHHPm HMX=TNT-70=30 PETN=HN-45=55 ETN=HMX-80=20 PETN RDX=Al-85=15 (80=20) NMP TAGN RDX=TNT-60=40 NTO RDX=HTPB-85=15 AMP TNAD BAED C=N-DNBTr=W-93/7 DINA DINA-Dynamite-90=10 Tetryl TATB NTO=HNE=W-76=19=5 DINGU=TNT-60=40 Bis-MNDPy NITRA DADPyOx TATB=TNT-60=40 NIGU=TNT-60=40 2-MNDPy TMNTz NC=DINA-60=40 DINGU=HNE=W-63=32=5 ADPy ADPyOx TNT AHDPy DADPy RDX=W-50=50 PETN=rubber-89=11 PETN (D ˆ 1) TAGN=W-50=0

D (g=cm3)

D (m=s)

Characteristics

1.71 1.73 1.78 1.81 1.68 1.81 1.66 1.73 1.76 1.81 1.65 1.75 1.72 1.78 1.75 1.47 1.74 1.81 1.57 1.67 1.64 1.51 1.57 1.62 1.61 1.71 1.86 1.64 1.79 1.60 1.56 1.80 1.79 1.69 1.63 1.53 1.55 1.63 1.67 1.69 1.60 1.72 1.69 2.92 1.20 0.98 2.48

9023 9008 9000 8773 8675 8611 8522 8489 8368 8319 8277 8160 8142 8114 8054 8048 7965 7959 7897 7876 7775 7773 7767 7713 7665 7573 7539 7523 7488 7361 7350 7328 7303 7269 7266 7228 7227 6986 6973 6963 6913 6813 6800 6501 6431 5516 5086

1.000 0.998 0.997 0.972 0.961 0.954 0.944 0.941 0.927 0.922 0.917 0.904 0.902 0.899 0.893 0.892 0.883 0.882 0.875 0.873 0.862 0.861 0.861 0.855 0.849 0.839 0.836 0.834 0.83 0.816 0.815 0.812 0.809 0.806 0.805 0.801 0.801 0.774 0.773 0.772 0.766 0.755 0.754 0.72 0.713 0.611 0.564

Obtaining optimum results has not been tried. The materials rarely possessed the favourable grain size for the charge fabrication. As a consequence the charge density D often Table 2. Performance Characteristics: Gurney Energy p 2EG Characteristics Explosive D (g=cm3)

HMX HMX=HN-70=30 ETN=HMX-80=20 PETN DINA HMX=ETN-65=35 HMX=HN=TAGN-45=40=15 HN=HMX-65=35 RDX DINA-Dynamite 90=10 RDX=HN-55=45 TeNHHPm HMX=TNT-70=30 RDX=Al-85=15 (80=20) RDX=TNT-60=40 NMP PETN=HN-45=55 BAED TNAD Tetryl Bis-MNDPy AMP RDX=HTPB-85=15 ANQ C=N-DNBTr=W-93=7 TMNTz 2-MNDPy NC=DINA-60=40 TAGN TATB=TNT-60=40 TNT PETN=rubber-89=11 DINGU=TNT-60=40 PETN (D ˆ 1) TATB DINGU=HNE=W-63=32=5 NIGU=TNT-60=40 NTO DADPyOx NITRA NTO=HNE=W-76=19=5 ADPyOx ADPy AHDPy RDX=W-50=50 DADPy TAGN=W-50=50

1.81 1.78 1.75 1.72 1.62 1.79 1.73 1.71 1.73 1.61 1.68 1.76 1.81 1.78 1.74 1.75 1.65 1.51 1.64 1.71 1.63 1.67 1.57 1.66 1.57 1.53 1.60 1.55 1.47 1.79 1.60 1.20 1.79 0.98 1.86 1.63 1.69 1.81 1.80 1.56 1.64 1.69 1.67 1.72 2.92 1.58 2.48

2.96 2.95 2.93 2.92 2.89 2.89 2.88 2.88 2.87 2.85 2.85 2.82 2.79 2.75 2.75 2.71 2.71 2.69 2.66 2.64 2.61 2.60 2.56 2.55 2.55 2.50 2.49 2.49 2.47 2.42 2.39 2.38 2.36 2.35 2.34 2.32 2.32 2.32 2.30 2.28 2.27 2.20 2.10 1.92 1.89 1.72 1.65

1.000 0.997 0.99 0.986 0.976 0.976 0.973 0.973 0.97 0.963 0.963 0.953 0.943 0.929 0.929 0.916 0.916 0.909 0.899 0.892 0.882 0.878 0.865 0.861 0.861 0.845 0.841 0.841 0.834 0.818 0.807 0.804 0.797 0.794 0.791 0.784 0.784 0.784 0.777 0.77 0.767 0.743 0.709 0.649 0.639 0.581 0.557

128 Hans-Heinrich Licht

Propellants, Explosives, Pyrotechnics 25, 126 ± 132 (2000)

Table 3. Performance Characteristics: Plate-Dent-Test Explosive

HMX=ETN-65=35 RDX=W-50=50 HMX RDX PETN HMX=HN-70=30 ETN=HMX-80=20 HMX=TNT-70=30 RDX=TNT-60=40 RDX=Al-80=20 HN=HMX-65=35 Tetryl TATB=TNT-60=40 TATB NTO RDX=HTPB-85=15 DINGU=TNT-60=40 ANQ TNT TAGN=W-50=50 DADPyOx TAGN DADPy PETN (D ˆ 1)

3

Table 4. Security Characteristics: DTA=TG

D (g=cm )

Dent (mm )

Characteristics

1.81 2.915 1.81 1.73 1.72 1.74 1.75 1.81 1.735 1.80 1.71 1.69 1.79 1.82 1.775 1.57 1.79 1.61 1.60 2.48 1.66 1.44 1.53 0.98

8.11 8.09 7.82 7.71 7.56 7.51 7.39 7.35 7.04 7.03 6.58 6.48 6.30 5.87 5.72 5.72 5.67 5.59 5.51 5.30 5.24 5.04 3.21 2.62

1.000 0.998 0.964 0.951 0.932 0.926 0.911 0.906 0.868 0.867 0.811 0.799 0.777 0.724 0.705 0.705 0.699 0.689 0.679 0.654 0.646 0.621 0.396 0.323

deviates strongly from the crystal density r and often attains only 90 ± 95% of r. Additives 1% are not mentioned here. It was supposed that such quantities do (practically) not affect the material properties. As the D measurements were obtained from Gurney energy investigations, the experimental conditions are given by their technology (see below). Most results originate from cylindrical charges (1 16 mm, 145 mm long) with metal con®nement. Bigger charges (1 25 mm, 250 mm long) were chosen for IHEs (TATB, TNT cast). Charges in the form of an open-faced sandwich were only applied in special cases. p 3.1.2 Gurney Energy 2EG For the determination of the Gurney energy we applied the experimental setup used by Defourneaux(2) for his ``coeÂf®cient balistique''. Here the de¯ection angle of the accelerated metal con®nement following a detonation is recorded by an X-ray ¯ash. The theoretical background allows to combine the ``coeÂf®cient balistique'' with Gurney's model. Thus the data from the ISL tests can be taken to calculate a Gurney constant(3). This was the precondition to correlate different charge geometries. When this test is realized with a Cu tube (1 25 mm, 250 mm long) a direct correlation exists with the copper cylinder test but with the important difference that the ISL method gives as a result a concrete numeral value and not a graph. A parametric study(4) showed that the result is in¯uenced by different factors: ± the geometry (cylinder, open faced sandwich, symmetrical sandwich), ± the mass ratio m (metal=explosive), ± the dimensions (tube length and diameter, plate thickness and width).

Explosive

TATB=TNT-60=40 TATB DADPyOx DADPy TNT ADPy AHDPy HMX=ETN-65=35 HMX=TNT-70=30 HMX=HN-70=30 NTO ETN=HMX-80=20 HMX NTO=HNE=W-76=19=5 DINGU=TNT-60=40 DINGU=HNE=W-63=32=5 HMX=HN=TAGN-45=40=15 RDX=Al-85=15 (80=20) RDX=W-50=50 RDX=TNT-60=40 HN=HMX-65=35 NITRA AMP TAGN RDX=HTPB-85=15 TAGN=W-50=50 TNAD ADPyOx RDX Tetryl TMNTz RDX=HN-55=45 DINA DINA-Dynamite (90=10) Nigu=TNT-60=40 PETN PETN (D ˆ 1) ANQ BAED PETN=HN-45=55 NC=DINA-60=40 2-MNDPy Bis-MNDPy NMP TeNHHPm PETN=rubber-89=11 C=N-DNBTr-93=7

Tex (6 C=/min)

Characteristics

376 373 356 350 305 300 300 291 289 288 284 283 280 280 257 254 239 239 237 235 232 226 225 225 218 218 218 210 210 210 210 209 207 207 203 202 202 201 200 200 191 190 190 190 188 185 160

1.000 0.992 0.947 0.931 0.811 0.798 0.798 0.780 0.769 0.766 0.755 0.753 0.745 0.745 0.684 0.676 0.636 0.636 0.630 0.625 0.617 0.601 0.598 0.598 0.580 0.580 0.580 0.559 0.559 0.559 0.559 0.556 0.551 0.551 0.540 0.537 0.537 0.535 0.532 0.532 0.508 0.505 0.505 0.505 0.500 0.492 0.426

These parameters have to be correlated if they are to be combined. The results from small tubes (1 16 mm) are only comparable with those from big ones (1 25 mm) in a certain m range. The same is true for plate charges and their relation to cylinders. The here cited Gurney constant is an average value from several experiments. 3.1.3 Plate Dent Test The dent volume or the dent depth formed after detonation of an uncon®ned cylindrical charge of 35 mm ; on a steel

Propellants, Explosives, Pyrotechnics 25, 126±132 (2000)

Performance and Sensitivity of Explosives

Table 5. Security Characteristics: Shock Sensitivity

Table 6. Security Characteristics: Gap Test

Explosive

Drop Weight (N.m) Characteristics

Explosive

ADPY AHDPy C=N-DNBTr=W-93=7 DADPy DADPyOx TATB TATB=TNT-60=40 NTO Nigu=TNT-60=40 HMX=TNT-70=30 DINGU=TNT-60=40 2-MNDPy TNT ADPyOx PETN=HN-45=55 TMNTz Tetryl RDX=TNT-60=40 DINA DINA=NC-90=10 TeNHHPm BAED NITRA RDX=HTPB-85=15 Bis-MNDPy RDX RDX=HN-55=45 TAGN HMX=ETN-65=35 HMX=HN-70=30 HMX=HN=TAGN-45=40=15 NC=DINA-60=40 ANQ AMP DINGU=HNE=W-63=32=5 ETN=HMX-80=20 HN=HMX-65=35 NTO=HNE=W HMX RDX=Al-80=20 PETN PETN (D ˆ 1) PETN=HN-45=55 PETN=rubber-89=11 NMP TNAD RDX=W-50=50 TAGN=W-50=50

> 25 (30) > 25 (30) > 25 (30) > 25 (30) > 25 (30) > 25 (30) > 25 (30) 25 22.5 20 17.5 17.5 15 12.5 12.5 12.5 6.5 ± 15 (10.75) 10 7.5 7.5 7.5 6.5 6.5 6.5 5.5 3.5 ± 7.5 (5.5) 5.5 5.5 5.0 5.0 5.0 5.0 4.5 4.5 4.5 4.5 4.5 4.5 4.0 1.5 ± 6.5 (4.0) 3.5 3.5 3.5 3.5 2.0 2.0 < 1.5 (1.0) < 1.5 (1.0)

DADPy NTO TATB TNT (cast) TATB=TNT-60=40 ANQ DADPyOx RDX=HTPB-85=15 RDX=TNT-60=40 Nigu=TNT-60=40 DINGU=TNT-60=40 HMX=TNT-70=30 TAGN RDX (class E) HMX Tetryl PETN

1.000 1.000 1.000 1.000 1.000 1.000 1.000 0.833 0.75 0.667 0.583 0.583 0.5 0.417 0.417 0.417 0.358 0.333 0.25 0.25 0.25 0.217 0.217 0.217 0.183 0.183 0.183 0.183 0.167 0.167 0.167 0.167 0.15 0.15 0.15 0.15 0.15 0.15 0.133 0.133 0.117 0.117 0.117 0.117 0.067 0.067 0.033 0.033

plate(5) can be evaluated from the plate dent test. Neither the height of the charge nor the mode of initiation is critical. A height of  100 mm and the initiation by a booster of 23 g PETN=wax-93=7 proved to be useful. As plates we used three discs (1 140  60 mm) of steel ST 37=XC 18 in a sand bed. In this report the results of the depth measurement are given because they are generally more easily accessible, although a volume determination can be realized quickly and in a simple manner by ``titration of the crater'' with water=ethanol.

129

D (g=cm3) Gap Test (kbar) Characteristics

1.58 1.83 1.84 1.63 1.79 1.65 1.68 1.57 1.73 1.69 1.79 1.81 1.49 1.62 1.78 1.62 1.62

> 50 (55) > 50 (55) > 50 (55) > 50 (55) 42 39 39 36 28 27 26 20 18 12.4 11 9.5 3.9

1.000 1.000 1.000 1.000 0.764 0.709 0.709 0.655 0.509 0.491 0.473 0.364 0.327 0.225 0.200 0.173 0.071

3.2 Determination of Sensitivity Data With respect to the sensitivity one has to distinguish between mechanical sensitivity tests (``1st reaction'') and detonability tests (``detonation: yes=no''). A third characteristic property is the thermal stability. 3.2.1 Thermal Stability Thermal stability is characterized with DTA=TG by the maximum of the decomposition peak when the sample is heated with 6 K=min beginning at ambient temperature. 3.2.2 Shock Sensitivity Shock sensitivity has been determined by a drop weight test (``BAM'')(6). The lowest shock energy of the ®rst reaction of 6 experiments was taken as security criterion. The experiments were realized with a 1 kg weight between 15 and 75 cm and a 5 kg weight between 15 and 50 cm drop height, respectively. 3.2.3 Gap Test For the gap test as a method to describe the detonability we selected the BICT procedure(7): Donor charge of 10 g RDX=wax-95=5 (D ˆ 1:6 g=cm3) and a test charge of 1 25 mm  25 mm with water as gap material. The relatively small dimensions become critical when less sensitive materials (TATB, NTO) were tested.

4. Results and Discussion The individual performance data are combined in Tables 1 ± 3, and those pertaining to security in Tables 4 ± 6 in a descending order. After normalization they give a ``characteristic''.

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Propellants, Explosives, Pyrotechnics 25, 126 ± 132 (2000)

Table 7. Explosives Abbreviation

ADPy ADPyOx AHDPy ANQ AMP BAED C=N-DNBTr=W-93=7 DADPy DADPyOx DINA DINA-Dynamit (90=10) DINGU ETN HN HNE 2-MNDPy Bis-MNDPy Nigu NITRA NMP NTO TeNHHPm TMNTz TNAD W

Chemial Compound

Ref.

4-Amino-3,5-dinitropyridine 4-Amino-3,5-dinitropyridine-N-oxide 2-Amino-6-hydroxy-3,5-dinitropyridine Aminonitroguanidine Azidomethyl-trinitrohexahydropyrimidine Bis(azido-methyl)-ethylendinitramine 4-Nitro-2-(1-nitro-1,2,4-triazol-3-yl)-1,2,3-triazole ( ‡ 7% wax) 2,6-Diamino-3,5-dinitropyridine 2,6-Diamino-3,5-dinitropyridine-N-oxide Bis(nitratoethyl)-nitramine DINA=Nitrocellulose-90=10 Dinitroglycolurile Erythritol tetranitrate Hydrazine nitrate Hexanitroethane 2-Methyl-nitramino-3,5-dinitropyridine 2,6-Bis(methylnitramino)-3,5-dinitropyridine Nitroguanidine 3-Nitramino-1,2,4-triazole Nitrato-methyl-trinitro-hexahydropyrimidine Nitrotriazolone 1,1,3,5-Tetranitrohexahydropyrimidine 2,4,6-Tris(methylnitramino)-1,3,5-triazine Tetranitraza-decalin Wax, paraffine

(8) (8) (8)

The exact names of chemical compounds and their origin are given in Table 7. The grain size or the distinction cast=pressed have only been respected in individual cases, although they may often be very important.

Figure 1. Performance and security ®gures of standard explosives.

(14) (14) (10) (8) (8)

(11) (11) (12) (9) (16) (15) (13)

4.1 Performance Data The maximum detonation velocity of HMX (49000 m=s) can only be obtained with a high charge preparation technology. So HMX has here only a Dexp ˆ 8773 m=s. After addition of a castable high explosive with positive oxygen balance (HN) a performance enhancement is

Propellants, Explosives, Pyrotechnics 25, 126±132 (2000)

Performance and Sensitivity of Explosives

131

Table 8. Performance and Security Figures (Standard Explosives : bold print) Explosive

ADPy ADPyOx AHDPy ANQ AMP BAED C=N-DNBTr=W-93=7 DADPy DADPyOx DINA DINA-Dynamite-90=10 DINGU=HNE=W-63=32=5 DINGU=TNT-60=40 ETN=HMX-80=20 HMX HMX=ETN-65=35 HMX=HN-70=30 HMX=HN=TAGN-45=40=15 HMX=TNT-70=30 HN=HMX-65=35 2-MNDPy Bis-MNDPy NC=DINA-60=40 Nigu=TNT-60=40 NITRA NMP NTO NTO=HNE=W-76=19=5 PETN PETN (D ˆ 1) PETN=HN-45=55 PETN=rubber-89=11 RDX RDX=Al-85=15 (80=20) RDX=HN-55=45 RDX=TNT-60=40 RDX=HTPB-85=15 RDX=W-50=50 TAGN TAGN=W-50=50 TATB TATB=TNT-60=40 TeNHHPm Tetryl TMNTz TNAD TNT

Performance 2.2 3.3

0.548 0.574 0.490 0.813 0.766 0.783 0.741 0.438 0.631 0.834 0.818 0.607 0.662 0.895 0.972 0.931 0.994 0.971 0.869 0.973 0.677 0.720 0.674 0.632 0.628 0.818 0.691 0.64 0.889 0.485 0.84 0.573 0.913 0.835 0.925 0.820 0.757 0.460 0.744 0.314 0.661 0.662 0.883 0.748 0.677 0.775 0.618

0.560

0.173 0.408

0.463 0.937

0.788

0.487 0.829

0.868 0.712 0.534 0.462 0.479 0.514 0.598 0.420

Security 2.2 3.3

0.798 0.233 0.798 0.080 0.090 0.115 0.426 0.931 0.947 0.138 0.138 0.101 0.399 0.113 0.099 0.130 0.128 0.106 0.513 0.093 0.294 0.092 0.085 0.405 0.130 0.034 0.629 0.112 0.063 0.063 0.062 0.058 0.102 0.085 0.102 0.208 0.126 0.021 0.109 0.019 0.992 1.000 0.125 0.200 0.233 0.039 0.406

0.057

0.931 0.671 Figure 2. Performance=Security: standard explosives.

0.189 0.020

0.187

enhancement. We suppose that HNE does not exhibit suf®ciently distinct explosive properties, that means HNE does not react in the detonation zone (of NTO). Addition of metals (15 ± 20% Al or 50% W) always results in a p dilution  effect with respect to the observed performance (D, 2EG ). On the other hand, in the plate dent test a higher performance is realized which is possibly only an abrasion effect of a secondary reaction.

4.2 Security Data 0.629 0.004

0.023 0.106 0.082

The strong in¯uence of metal addition on shock sensitivity should be emphasized. The maximum=minimum results of the thermal stability only differ by the factor 2. There are materials which have only a limited stability up to 150  C, on the other hand compounds exist which endure 4350  C ± not easy to realize for any organic compound, especially for an explosive.

0.036 0.992 0.764 0.035 0.406

Example (NTO): Performance 3.3: 0.882 (Tab. 1)* 0.784 (Tab. 2)* 0.705 (Tab. 3) ˆ 0.487 Security 2.2: 0.755 (Tab. 4)* 0.833 (Tab. 5) ˆ 0.629

observed despite of a reduced density. This lower density, especially the lower molecular weight of the hydrazine nitrate consisting of light elements (H !) is responsible for the reduced ballistic performance of such formulations. This argument is also valid for the high D of ANQ (exceeding that of RDX) and its disappointing low Gurney energy. Comparable results were found for PETN=HN. An addition of HNE (with its advantageous oxygen excess) to NTO did not result in the desired performance

5. Combination of Performance and Security Data Figure 1 demonstrates how performance and security characteristics can be composed by addition of single data. More information is obtained when the performance and security respectively characteristics are multiplied with each other. This results in a ``performance ®gure'' (Figs. 2 and 3), according to 2 or 3 parameters taken into account (Table 8). The graph (Fig. 2) shows that common explosives are found below a virtual border line for which is valid that high explosives are sensitive, and ± on the other hand ± insensitive explosives, which can be handled without restrictions, do not have an attractive performance.

6. Application But also the ``ideal explosive candidate'' can be recognized approaching the aim ``high performance ‡ high security'' (Fig. 3). Among the discussed energetic materials we ®nd TATB and its cast mixtures with TNT and perhaps also

132 Hans-Heinrich Licht

Figure 3. Performance=Security: exceptions.

DADPyOx. (HMX=TNT is a critical case: It exhibits an interesting performance/sensitivity ratio when only two tests are taken into account). The IHE TATB and DADPyOx accomplish an important precondition as they possess the best structure for an energetic molecule: Cyclic, aromatic, highly nitrated, a stabilizing effect from the intramolecular hydrogen bonding between the nitro and the adjacent amino groups. Mixtures of IHE and sensitive but brisant high explosives may be in practice a reasonable compromise with respect to performance and sensitivity. The application of the described procedure allows to test future developments and novel formulations with regard to a progress towards the ideal high explosive.

7. References (1) a) H. H. Licht, ISL-R 105=91; b) H. H. Licht and B. Wanders, ISL-CO 206=91.

Propellants, Explosives, Pyrotechnics 25, 126 ± 132 (2000) (2) a) M. Defourneaux and L. Jacques, 5th Symposium on Detonation, Pasadena, August 18 ± 21, 1970. b) M. Defourneaux, Sciences et Techniques de l'Armement 3 & 4, 73 (1973). (3) H. H. Licht and A. Baumann, ISL-RT 521=88. (4) H. H. Licht, Proc. 16th International Pyrot. Seminar, JoÈnkoÈping, June 24 ± 28, 1991, 314. (5) H. H. Licht and J. Schwab, ISL-R 112=91. (6) H. Koenen, K. H. Ide, and K. H. Swart, Explosivstoffe 9, 30 ± 42 (1961). (7) a) F. Trimborn, Explosivstoffe 15, 169 ± 175 (1967); b) F. Trimborn and R. Wild, Propellants, Explosives, Pyrotechnics 7, 87 ± 90 (1982). (8) a) H. Ritter and H. H. Licht, J. Heterocycl.Chem. 32, 585 ± 590 (1995); b) H. H. Licht and B. Wanders, ISL-RT 510=89; c) H. H. Licht, B. Wanders, and H. Ritter, ISL-R 101=89; d) H. H. Licht, 24th Internat. Annual Conference of ICT, June 29 ± July 2, 1993, Karlsruhe, Fraunhofer-Institut fuÈr Chemische Technologie, ICT, P®nztal, Germany. (9) H. Ritter, I. Bischoff, G. Kriegel, L. Philipp, and H. H. Licht, ISL-R 130=84. (10) a) H. Ritter, Ph. Michaud, M. SchaÈfer, B. Wanders, and H. H. Licht, ISL-PU 360=96; b) H. Ritter and H. H. Licht, ISL-RT 502=96; c) H. Ritter, S. Braun, P. L. Carrette, and H. H. Licht, ISL-RT 504=98. (11) a) H. Ritter, N. Fell, and E. Gallois, ISL-RT 502=90; b) H. H. Licht, H. Ritter, N. Fell, and B. Wanders, ISL-R 101=92; c) H. Ritter and H. H. Licht, Propellants, Explosives, Pyrotechnics 18, 81 ± 88 (1993). (12) a) H. H. Licht, S. Braun, M. SchaÈfer, B. Wanders, and H. Ritter, ISL-R 104=94); b) H. H. Licht and H. Ritter, J. Energ. Mat. 12, 223 ± 235 (1994); c) H. H. Licht, S. Braun, M. SchaÈfer, B. Wanders, and H. Ritter, ISL-R 124=97. (13) a) H. Ritter, Ph. Michaud, M. SchaÈfer, B. Wanders, and H. H. Licht, ISL-RT 502=96; b) H. Ritter, M. SchaÈfer, and H. H. Licht, ISL-RT 510=96. (14) a) H. Ritter and Ph. Robert, ISL-RT 506=86; b) H. Ritter, ISL-CO 253=86; c) H. Ritter, ISL-CO 243=89. (15) H. Ritter, S. Braun, and N. Fell, ISL-R 114=92. (16) H. Ritter and B. Wanders, ISL-RT 511=8.

(Received January 12, 2000; Ms 2000/003)