decomposes at 180 ° C
NIBGTN is an acronym for nitroisobutylglycerol trinitrate. The proper name for this compound is 1,3-propanediol, 2-nitro-2-[(nitrooxy)methyl]-, dinitrate (ester). Other names include 1,3-propanediol, 2-(hydroxymethyl)-2-nitro-, trinitrate (ester); nitroisobutanetriol trinitrate; 1,3-propanediol, 2-nitro-2-[(nitrooxy)methyl]-, dinitrate; 1,3-propanediol, 2-(hydroxymethyl)-2-nitro-, trinitrate; nitroisobutyl glyceryl trinitrate; nitroisobutyl glycol trinitrate; nitroisobutylglycerintrinitrate; and trimethylol nitromethane trinitrate. This compound is a viscous, yellow, oderless, oily liquid similar to nitroglycerine. This compound was first experimented on back in 1912, and the current method of preperation was developed by Dr. A. Stettbacher in 1934. It was proposed to use NIBGTN as a substitute for nitroglycerin in commercial explosives, but its greater instability and poor thermal stability made it difficult to work with. The detonation velocity listed above can be achieved only by confining the explosive and using a powerful detonator, otherwise the detonation velocity is a rather low 1000-1500 m/s.
|ethyl ether||500-mL Erlenmeyer flask|
|nitric acid||graduated cylinder|
|sodium bicarbonate||stirrer/stirring rod|
|sulfuric acid||vacuum desiccator|
Prepare an acid mixture of 99.1 mL of 99% sulfuric acid and 76.3 mL of 99% nitric acid in a 500-mL Erlenmeyer flask, cool this mixture in a salt-ice bath. Slowly add, with stirring, 50 g of tris(hydroxymethyl)nitromethane to the flask while keeping the temperature below 15 °C. The addition should take about 30 minutes. Stir the mixture for an additional 30 minutes while allowing the temperature to drop to 5 °C. Transfer the contents of the flask to a separatory funnel and allow it to stand for several minutes while the layers separate, then draw off the bottom layer of acid. Wash the remaining oil with water, then with sodium bicarbonate solution, and finally twice more with water. The washed oil should be neutral to litmus, if not, wash with more water until it is. Combine all of the washings and mix them with the spent acid. Cool this mixture and extract it several times with ethyl ether to remove additional product. Wash the ethyl ether extracts with water, evaporate the ethyl ether, and add the remaining product to the other washed product. Dry all of the NIBGTN in a vacuum desiccator. The yield is around 95%. Sometimes the NIBGTN will form an emulsion that can take awhile for layers to separate fully, this can be mitigated by heating all wash water to 43.5 °C, using concentrated sodium sulfite solution instead of sodium bicarbonate, and bubbling in compressed air while washing. You will need a graduated cylinder for measuring liquids, a stirring rod or magnetic stirrer for mixing, and a thermometer to monitor the temperature.
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