Nitrostarch explosives are similar to dynamite except that they contain the solid nitrostarch instead of the liquid nitroglycerin. They are not
subject to exudation and are not injured by low temperatures. They supply a possible outlet for a certain amount of cane sugar in the explosives
industry, for nitrosucrose in admixture with nitrostarch can be stabilized more cheaply and more conveniently than it can be by itself. Wyler has
discovered that a mixture of cane sugar (glucose or cerelose) with 10% or more of its weight of powdered corn starch or cassava starch can be nitrated
to yield a fluffy pulverulent mass which can be stabilized satisfactorily and can be handled as a powder at ordinary temperatures or higher.
"100 lbs. Of finely ground cane sugar is thoroughly mixed with 25 lbs. of dried corn starch and the mixture fed to 360 lbs of 95% HNO, keeping the
nitration mixture at a low temperature, say, below 20ºC. at the end of this operation, all of the starch and all of the sugar will have gone into
solution. Next 510 lbs. of oleum of about 105% H2SO4, strength is added slowly with continued cooling and stirring. When all of this oleum has been
added, the nitrated sugar will have separed into a doughy plastic mass. This is separated from the acid and transferred to a kneading tank supplied
with a current of tap water, where, in a short time the doughy mass is converted into a fine, pulverulent precipitate which is filtered, washed with
tap water, and transferred to a stirring tank containing dilute alkali solution in which it is stirred for one hour or more to stabilize the nitrated
product, which consists of a mutual solid solution of nitrated sugar and nitrated starch. The alkaline mixture is then filtered, washed with tap
water, and dried at about 40°C."
Wyler also describes another method of nitration, with mixed acid instead of with strong nitric acid and oleum. The same amount of material is
nitrated with mixed acid containing 64% sulfuric acid, 34% nitric acid, and 2% water. The temperature of the nitration is kept, preferably, below
20ºC. And the gummy crude product is removed and handled as has been described.
The "dried co-nitrated product is a slightly yellow, dusty, low density powder, readily detonable and soluble in the usual solvents used for gelatin
explosives and for lacquers. When made in the manner just described the product will contain about 14.50% N present as nitrate, and its packing
density will be about one-third that of ordinary nitrostarch." It is "normally of a finely divided or pulverulent nature, even when not subjected to
any cominuting operation," and is "a particularly valuable component for use in explosive compositions where a low density or ‘high stick count’
is desired." |
