TNPEN
molecular mass
318.16 g/mol d
ensity
1.25 g/mL
(O2N)3C6H2OCH2CH2(ONO2)
explosive velocity
appx 6000 m/s
TNPEN is an acronym for ß-(2,4,6-trinitrophenoxy) ethanol nitrate, also called 2,4,6-trinitrophenoxyethyl nitrate; or glycoltrinitrophenylether nitrate. TNPEN was first prepared by H.A. Lewis back in 1925, others have since revised the method, with this particular preparation developed by R.C. Elderfield in 1943. TNPEN will ignite when heated in the open and will detonate if struck as if by a hammer, so its stability is not that low, compared to TNT it is as stable and has 122% the explosive power. There is some conflicting data that indicates the stability may be lower. The recommended uses of this explosive are in detonators or boosters, and as an ingredient in propellents. The detonation velocity ranges from 5500 m/s to 6600 m/s depending on the density which can range from 1.15 g/mL to 1.6 g/mL
CHEMICALS APPARATUS
acetone beaker
ß-(2,4-dinitrophenoxy) ethanol 250-mL Florence flask
ethyl alcohol graduated cylinder
nitric acid filter paper
sulfuric acid stirrer/stirring rod
water thermometer
Prepare a solution of 10 g of ß-(2,4-dinitrophenoxy) ethanol in 55 mL of 94% sulfuric acid in a small beaker. Prepare a second solution of 21.5 mL of sulfuric acid, 13.2 mL of nitric acid, and 15.7 mL of water in a round bottomed 250-mL Florence flask, chill this solution to between 0-10 °C with a salt-ice bath. It does not matter what concentration of acids are mixed so long as the total water content comes out to 15.7 mL. While stirring, slowly add the ß-(2,4-dinitrophenoxy) ethanol solution to the cold acid mix. When the addition is complete, the temperature is raised in 30 minute intervals to 20 °C, 30 °C, 40 °C, 60 °C, and in a 15 minute interval to 70 °C. After chilling, the cream-colored crystals are filtered using glass filter paper, washed free of acid, and recrystallized by dissolving in acetone and adding ethyl alcohol. You will need a graduated cylinder for measuring liquids, a stirring rod or magnetic stirrer for mixing, and a thermometer to monitor the temperature.