PowerLabs Mannitol Hexanitrate Synthesis

Introduction:

Mannitol Haxanitrate or Nitromannitol, Nitromannite, Nitranitol, Mannitrin, is a secondary explosive formed by the nitration of Mannitol (Manna Sugar, mannite), a simple sugar. The product finds medicinal usage as a vasodilator, and also commercial usage as an explosive in blasting caps. Its sensitivity is considerably, particularly at high temperatures (>75C) where it is even more sensitive than nitroglycerine.

Materials:

Reactants:	Materials:
Mannitol (C₆H₁₄O_6(s))	2 Glass Beakers
98% Sulfuric Acid (H₂SO_4(aq))	Stirring Rod
70% Nitric Acid (HNO_3(aq))	Thermometer
Water (H₂O_(l))	Ice Bath
Ethanol (C₂H₆O_(aq))

Procedures:

There are two procedures I am familiar with for producing Mannitol Hexanitrate. The first one, obtained from the Internet, called for adding the mannitol to Nitric Acid first, and then adding Sulfuric Acid. I did not particularly like this method because the energy of dehydration for the water that comes with using dilute HNO₃ will very quickly heat the mixture, likely leading to nitration runaway. This method was not very successful. The following method was then attempted:

Mannitol added to a nitrating mixture

A nitrating mixture such as is commonly used for the nitration of Cellulose, Glycerin, starch, etc was prepared with the proportions (by volume) 35% HNO₃ / 65% H₂SO₄. This mixture was cooled to 0C in an ice water bath and mannitol was slowly added whilst the mixture was stirred and the temperature kept below 15C. After the addition of 1g/mannitol per 10mL acids was completed the mixture was stirred and the temperature was allowed to return to ambient.

Washing and neutralizing acid on nitromannitol. The mixture is then added to twice its volume in ice cold water, filtered, and the product is first neutralized with sodium bicarbonate solution, and then purified by running cold water and Ethanol through it. A final filtration removes a collection of small white particles.

Results:

The product consisted in small white particles with a melting point in the 106 - 108 range. Deflagration from flame occurs at a slightly higher rate than nitrostarch.

Relevant Links:

NitroCellulose: Uses the same nitrating method described above.
Nitro Starch: Also uses the same nitrating method described above.

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Last updated 11/02/10