TABLEVI.
GAS-HAMMER DETONATION TESTSUSING CAPPED P I P E F I L L E D WITH NITROGEN
.”
Additive Xone Xone
+
2% Cr acetyl acetonate
Driving Pressuie, I,b./Sq. Tn 880 1230
Driving Gas Used N2
850 1230
N2
XZ
N2
Results Detonation Detonation
N o detonation No detonation
STORAGE STABILITY AND CORROSION
blononitromethane is a coinmrrcial commodity regularly shipped and handled with safety in single-trip 55-gallon drums. These drums are coated on the inside with a lacquer to prevent iron salts from discoloring the nitromethane. That nitromethane is perhaps less of a fire hazard than gasoline can be illustrated by lighting a few milliliters of each in open evaporation dishes with a Bunsen burner. The mononitromethane is the harder to ignite and burns with a lazy almost nonluminous flame.
‘
TABLE VII.
.50-CALIBER MACHINE GUS FIREO S MONONITROMETHANE
]EFFECT O F
(95 to 06% samples used)
(96% mononitromethane sainole used)’
4% gasoline
1323
INDUSTRIAL AND.ENGINEERING CHEMISTRY
July 1948
. Corrosion and stability tests carried out a t room temperature and at 50” 0. with mononitromethane showed it to be stable and essentially noncorrosive to type 464 stainless steel, 25 aluminum, WDlOlO cold-rolled steel, the coating of the standard shipping drum (Ohio Kote No. 37), and to a henol-formaldehyde type of coating (Chemical Warfare Service gpecification 196-131-207). Tests to determine the pressure stability of mononitromethane revealed that, during storage in glass apparatus as shown in Figure 1 ( 2 ) a t 50” C., a partial vacuum was created above the liquid. For the commercial product (95 t o 96%) this pressure decrease was 0.2 atmosphere in all cases; this suggested that oxygen was being absorbed from the air above the nitromethane. The 100% sample gave less than one half this pressure drop. Hence, it was * concluded that the pressure drop was caused by impurities in the products. This view was supported by the fact that the 95 to 96% materials decolorized acid permanganate and gave a positive aldehyde test with Tollens reagent, whereas the 100% material did neither. (Formaldehyde is a probable impurity in commercial mononitromethane.) The samples of mononitromethane that resulted from these 50” C. storage tests were more sensitive to detonation by impact (hammer impact tester) than the original material. However, the increase in sensitivity was small compared to the decrease in sensitivity that can be obtained by the addition of gaqoline. It was, therefore, judged impractical to consider purification to remove the material which caused the increase in sensitivity on exposure to air at elevated temperatures.
ReBUltbti Type of Container“ Amniu- No. of DetoExploIL’0 and Additiveb nition‘ Trials nationk ?ions Fires effect 1-gal. paint can None AP 3 0 0 0 1 3 1 None I 3 0 1 None T 4 0 0 0 4 2% catalyst AP 1 0 0 0 1 1-gal. can, 18 gage None None 2% catalyst I 5 0 5 3 2% catalyst 0 8 T 12 0 4 2% catalyst 5 0 3 2 0 4Y0 2% catalyst gasoline T 5 0 0 2 3 . Same 1-quart can, 18 gage AP 5 0 0 0 5 None I 9 0 0 3 6f None 0 8f AP 0 1 0 2% catalyst I 5 0 2 4 1 2% oatalyst T 5 0 0 1 4 2% catalyst AP 8 0 0 0 8 2% catalyst 4% gasoline Same I 3 0 1 1 . 1 11-gal. can, 0.25-in. 0 8 0 None none 1 1 Kone ?1 1 Nnnn 3 0 0 8f 2% Eatalyst 4 1 2 2% catalyst 1 4 0 2% catalyst 8 0 0 2% catalyst 4% icasoline I 2 0 1 1 1 Same 1-quart can, 0.25-inch 0 0 0 8 Nnnn AP 8 .. . 0 7 7 1I 8 None 0 0 2 6 T 8 None 5-gal. paint can, 1.25 steel side h I’ 1 0 0 0 1 None %gal. paint can I 1 0 0 01 0 2% catalyst T 1 0 0 2% catalyst 55-gal. drum, 0.25-inch steel plate welded on target side AP 1 0 0 0 1 None I 1 0 1 1 0 None 55-gal. drum None Nones None None Unless otherwise noted, containers were rectangular and were filled to 10% void. b AP I n all E cases armorthe piercing; catalystIwas = incendiary: chromium acetyl = tlacer. aaetonate.
+
+
+
d More than one result, as a fire and an explosion, can nccnl on a given trial. e Hits were above the liquid level in the container. f Five hits were above liquid level in the container. Q Drum contained only 2 gallons mononitromethane.
CONCLUSIONS
Although mononitromethane is, under wdinafy conditions, a relatively stable, noncorrosive chemical that can be shipped, handled, and used with safety if the usual precautions for volatile solvents are observed, it is nevertheless a powerful explosive and can be readily detonated under certain conditions. Mononitromethane can be detonated by mechanical impact, gun fire, sudden impact of high pressure air, and by high velocity flow through pipes containing closed ends, constrictions, and other obstructions to flow. The sensitivity of mononitromethane to detonation can be diminished, but not eliminated, by the addition of several materials of which gasoline is probably the most practical. The use of mononitromethane as a propellant for the launching of buzz bombs will require an injector system especially designed to eliminate the conditions shown to cause detonation of mononitromethane while being transferred through pipes, valves, nozzles, etc. ACKNOWLEDGMENT
Acknowledgment is made for the helpful information and advice given throughout the course of this work by Johnston, Kaplan, Seifert, Stosick, and Weissbluth of the Guggenheim leronautics Laboratory, California Institute of Technology.
LITERATURE C I T E D
(1) Bellinger,Friedman, et aE., IND.ENG.CHBM., 38,180 (2) Ibid., pp. 310-20. (3) Ibid., pp. 627-30. RECEIVED May 14, 1046. Warfare Service.
b (1946).
Released by authority of the Chief, Chemical
Low Temperature Manufacture of Chemical Rubber-Correction In the paper, “Low Temperature Manufacture of Chemical Rubber” [IND. ENG.CHEM.,40, 769 (1948)l the correct capacity of the coolant surge tank shown in the “Condensed Flow Chart for 41’ F. Polymer,” is 10,000 gallons; in Table I, footnote a should read “Quantities in parts per hundred based on dry weight”; in Table 11, Test Conditions, the correct time is 15 minutes at 100 a C.; page 772, line 19 under Pigment Area should read 2500-gallon wooden tank instead of 25-gallon; same page, line 1under Reactions should read 24 instead of 25; and page 776, in line 16 under Physical Properties, “valves” should be “values.” WILL H. SHEARON, JR. J. P. MCKENZIE MARTINE. SAMUELS
