decomposes at 208 °C
explodes at 345 °C
This particular explosive is of curious interest, it is not really used that much but it still explodes. It is a pale yellow crystalline substance that melts with some decomposition at 208 °C. It is very brisant, usually used in detonators or booster charges. The explosive force is slightly greater than TNT. The primary ingredient is carbanilide, also known as sym-diphenylurea, which can be made from heating aniline and urea together at 160-165 °C, or by the interaction of phosgene and aniline. A more technical name for this explosive is 2,2',4,4',6,6'-hexanitro-N,N'-diphenylurea or sym-dipicrylurea.
|nitric acid||buret/separatory funnel|
|sulfuric acid||Erlenmeyer flask|
40 g of carbanilide is dissolved in 60 mL of 100% sulfuric acid in a small beaker, pour the solution into a buret or separatory funnel and add it drop by drop during a 4 hour period in to 96 mL of 100% nitric acid, in an Erlenmeyer flask, while the mixture is stirred vigorously with a mechanical stirrer and its temperature is maintained at 35º to 40º C. After all of the solution has been added, the stirring is continued and the temperature is raised to 60 °C over 30 minutes and held at that temperature for another 60 minutes. The mixture is allowed to stand over night where it can cool to room temperature. After sitting, crushed ice and water are added to the solution, then it is poured over a filter to collect the crystals that should have formed. The crude tetranitrocarbanilide is washed thoroughly with water and allowed to dry in the air. In the second stage, 10 g of crude tetranitrocarbanilide is added to a mixture of 9 mL of concentrated sulfuric acid and 16 mL of nitric acid in a small Florence flask, and the material is heated on a steam bath or hotplate, to no more than 100 °C, for 1 hour with constant stirring. After cooling, crushed ice and water are added to the mixture, then it is poured over a filter to collect the crystals. The product is washed with 500 mL of cold water, then treated with 500 mL of hot water, and dried in the air. The resulting hexanitrocarbanilide is of good quality for use as an explosive. You will need a graduated cylinder for measuring liquids, and a thermometer to monitor the temperature.
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