Junk test

Mayrhofer Stability Test. A modification of the Bergmann-Junk Test (see Vol 2, B102-R) for testing the stability of NC and propellants. Mayrhofer recommended the use of 20ml of a 2% Kl soln instead of w for the quant collection of decompn products. He also tested NG contg propints in both dry and si moist states, and found that while a stable sample behaved in a similar manner whether heated dry or moist, an unstable powd decompd rapidly in the presence of traces of w. Tonegutti (Ref 3) considered this test reliable for ballistites and unreliable for cordites... 

For nitrocellulose, including guncotton, the most suitable stability test is the B and J (Bergmann and Junk) test in which 2 g dried material is heated for 2 h at 132°C, the gases evolved being dissolved in water. The nitric acid in this water is reduced to nitric oxide, which is measured by volume. 

Heat Tests. Under this term may be placed all the stability tests which involve heating an explosive, eg Abel Heat Test, Acidity Measurements (pH measurements), American Test at 65.5° or 80°, Bergmann-Junk Test, Brame s Test, Brunswig s Test, Chiaraviglio Corbino Test, Conductivity Method (De Bruin de Pauw) Continuous Test, Deflagration Test, Desmaroux Test, Dupre s Vacuum Test, Dutch Test,... 

Junk Test. See Bergmann-Junk Test in Vol 2 of Encycl, p B102-R... 

CDj) T. Urbanski, Vol 2(1965), pp 22-31 gives methods for determining the Stability of Nitric Esters, which include Abel Heat Test, Litmus Test (Vieille Test), Heat Test at 134.5°C, Silvered Vessel Test, Loss of Weight Test, Will Test, Bergmann Junk Test and Manometric Test... 

The acids attack KI and the liberated iodine colors the starch paper c)Koehler Mar-querol(Ref 2) do not recommend the use of Abel s test for NC propellants contg Ca carbonate - Bergmann-Junk test(qv) gives more reliable results... 

NAC with N ca 11.5% has been used in Italy as an ingredient of DEGDN propellants (polveri al nitroglicol). Following are Ital military specification requirements (Ref 7) nitrogen content 11.20-11.70%, fineness <90, acetyl content > 1.50,% ash < 1%, lime calcd as CaO 5L 0.30%, stability by 80° Abel test > 25 by 135° Ger test 50 min and by 131° Bergmann-Junk test < 1.75 cc of NO... 

Nitration of amylose was carried out according to the Will Lenze method, using mixed nitric-sulfuric acid as described under nitration of starch(Ref 4). The resulting product had N=12.96%, soly in ale 20% and stability(by Abel and Bergmann-Junk tests) higher than for aminopectin nitrate(Ref 5). 

Bergmann-Junk test 1 VIII 2 B102-B103... 

B-J test see Bergmann-Junk test 2 B102—B103... 

Bergmann and Junk test. The Bergmann and Junk [92] test consists in determining the quantity of N0+N02 lost by the sample (2 g of nitrocellulose or 5 g of nitrocellulose powder) when heated at 132°C for 2 hr. The test tube is closed at one end with a hydraulic seal (Fig. 4). The latter may be ball shaped (a) or (more frequently) bell shaped (b). After the test, the tube is withdrawn from the thermostat and cooled to the room temperature. Water is sucked into the tube, which is then... 

Fig. 4. Tubes for Bergmann and Junk test (a) with balls, and (b) with tubular ending, (c) thermostat with tubes.

Bergmann Junk Test(B-J Test). The original test, designed by Bergmann Junk(Ref 1) for testing stability of NC and propellants, was modified during WWI by Mayrhofer(Ref 2) and later by Meerscheid-Hullessem(Ref 4). The test has been widely used in Europe and to some extent in the US... 

Thermal Stability by 82.2° K1 Test Bergmann-Junk Test, ca the same as NG and Velocity of Detonation, 7270 m/sec. This compd and related a-mono a,a disubstituted glycerol nitrates have been claimed to be useful expl components... 

N 13.59%. Two mildly expl isomers were prepd by nitrating the corresponding diols cis-Cyclohexane - 1,2-diol Dinitrate, prismatic rods (from hot ligroin), mp 24.5 25°, nQ 1.4790 at 21° impact test value with 2 kg wt (Rotter machine) 60 cm vs 100 cm for TNT fumes at 170° Bergmann-Junk test 0.67 mg NO evolved/ lg sample in 20 hrs at 106°... 

Trans-Cyclohexane - 1,2 dial Dinitrate, pltlts (from- hot ligroin), mp 18 5 19° impact test value 72-85 -cm fumes at 1.65°, ignites at 185° Bergmann-Junk test 0.67 mg NO evolved/ lg sample Refs 1) Beil —not found 2) U. R. Christian C.B. Purves, CanJChem, 29, 929 33 (1951) CA... 

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