Expansion in the lead block test—

Ethanolamine dinitrate is a strong explosive, since its expansion in the lead block test, as determined by Naoum, is 430 cm3. It has a remarkably low sensitiveness to impact. Nevertheless its tendency to dissociate and to form free nitric acid and its low stability prevent any practical application. 

The rate of detonation of ammonium chlorate of density 0.9 g/cm3 is 3300 m/sec, and its expansion in the lead block test is about 250 cm3. Ammonium chlorate is sensitive to impact it explodes if a 2-kg weight is dropped on it from a height of 15-20 cm. It takes fire from the flame produced by a safety fuse, and if confined the flame causes it to explode. 

As for its explosive strength, guanidine perchlorate is similar to tetryl. Its sensitiveness to shock is comparable with that of picric acid. The rate of detonation is 6000 m/sec at a density of 1.15 and the net expansion in the lead block test is about 400 cm3. 

Urea nitrate is insensitive to friction and to impact. The density of the substance subjected to a pressure of 1500 kg/cm3 is 1.59 g/cm3. In the lead block test it caused an expansion of 260 (Kast) or 270 cm3 (T. Urbanski, Kapuscinski, Wojcie-chowski [59]). It detonates somewhat better than ammonium nitrate and guanidine nitrate, but a No. 8 detonator did not provoke complete detonation. Medard [59a] reported that urea nitrate gives a relative figure of the lead block expansion 79.6 (picric acid = 100) and the rate of detonation of 30 mm dia. charges is ... 

Ammonium permanganate detonates with a rate of 1700 m/sec. It causes an expansion of 100-125 cm3 in the lead block test. 

According to Medard [12], in the lead block test nitromethane gives figures similar to picric acid. T. Urbanski and Pawelec [35] found 325-360 cm3, averaging 345 cm3, i.e. 110% of that of picric acid. The same authors determined the lead block expansion when nitromethane was detonated by means of a No. 8 detonator Mid 1 or 5 g of tetiyl. The expansion given by tetryl was deducted from the bulk expansion (Table 126). 

The explosive properties of nitrosugars have been examined by Monasterski [13]. This author reported that saccharose octanitrate developed a heat of explosion of 950 kcal/kg, and produced in the lead block an expansion of about 300 cm3. In the drop test it exploded from the impact of a 2-kg weight falling from a height of at least 20 cm. Maltose octanitrate, in the lead block, caused a net expansion of some 260 cm3. 

Tests conducted at temps of -80° and -183° with expls commonly used in detonators showed that the vel of deton and Trauzl lead block expansion values were practically unaffected, while brisance, as indicated by the lead plate test, was greatly reduced. The performance of detonators, as judged by an initiation test on unconfined cartridges contg LOX (qv) expls, was also greatly reduced. Only detonators contg Mannitol Hexanitrate, when immersed in LOX expls for 3 minutes at —183°, resulted in complete deton (Ref 1)... 

The power of explosives is determined in a conventional manner. The most usual test is the determination of the lead block expansion and the rate of detonation. In some countries the crushing of lead and copper cylinders is determined. 

It must be pointed out that experiments intended to attach a nitro group to a nitrogen atom failed. The substance is stable, since it did not undergo decomposition after being maintained for 200 hr at 70°C, and its temperature of initiation is 187°C. Its explosive properties are as follows. At a density of 0.62 g/cm3 it detonates with a rate of 4030 m/sec, the lead block expansion is 325 cm3 and its relatively low sensitiveness to shock is indicated by the fact that it is exploded in a drop test by a 2-kg weight falling from a height of 60 cm. 

Propylene glycol dinitrate is a colorless liquid of characteristic aromatic odor, more volatile and less viscous than trimethylene glycol dinitrate with which it is isomeric. Its specific gravity (20°/4°) is 1.368 at 20°. It boils at 92° at 10 mm., and does not freeze at —20°. Its solubilities, gelatinizing power, and explosive properties are substantially the same as those of its isomer. Indeed, Naoum 60 reports that it gave exactly the same expansion as trimethylene glycol dinitrate in the Trauzl lead block test, namely, 540 cc. 

Lead Black(or Cylinder) Comprsssian(ar Crushing) Tsst(Lead Block Test or Hess Test) (Stsuchprobc nach Hess, in Ger) (Iipreuve au block de plomb, in Fr) is one of the German teats for brisance, also called percussive force. It will be described in Vol II, under Compression Testa Lead Black Expansion Test. See Trauzl Test Lead Plate Tsat. See under Plate Tests... 

Behrens [65] measured the lead block expansions given by tetranitromethane alone or in mixtures with nitrogen dioxide said benzene. Detonators of various strengths from No. 1 to No. 8 were used as initiators. Tests with TNT and nitroglycerine were made for comparison. The results obtained are shown in Table 128. 

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