Explosive Theory

This website is contains information about the chemistry behind explosives

Monday, August 21, 2006

NITROGLYCERIN

Nitroglycerin has more names than most, they include its proper name of glycerol trinitrate as well as 1,2,3-propanetriol trinitrate; glyceryl trinitrate; glycerol nitric acid triester; nitroglycerol; trinitroglycerol; glonoin; trinitrin; blasting gelatin; blasting oil; S.N.G.; Adesitrin; Angibid; Angiolingual; Anginine; Angorin; Aquo-Trinitrosan; Cardamist; Cordipatch; Coro-Nitro; Corditrine; Deponit; Diafusor; Discotrine; Gilucor; GTN; Klavikordal; Lenitral; Lentonitrina; Millisrol; Minitran; Myoglycerin; Nitradisc; Nitran; Nitriderm-TTS; Nitro-Bid; Nitrocine; Nitrocontin; Nitroderm TTS; Nitrodisc; Nitro-Dur; Nitrofortin; Nitrogard; Nitro-Gesanit; Nitroglin; Nitroglyn; Nitroglyn; Nitrolan; Nitrolande; Nitrolar; Nitrolent; Nitrolingual; Nitro Mack; Nitromex; Nitronal; Nitrong; Nitro PRN; Nitrorectal; Nitroretard; Nitrosigma; Nitrostat; Nitrozell-retard; Nysconitrine; Percutol; Perlinganit; Reminitrol; Suscard; Sustac; Sustonit; Transderm-Nitro; Transiderm-Nitro; Tridil; Trinalgon; Trinitrosan; and Vasoglyn. That is quite a list, most are drug names though.
CHEMICALS
APPARATUS
chloroform
1000-mL beaker
glycerol
buret
nitric acid
desiccator
sodium carbonate
1000-mL Florence flask
sodium chloride
graduated cylinder
sulfuric acid
separatory funnel
water
thermometer
Prepare a mixture of 200 mL of 98-100% nitric acid and 300 mL of 98-100% sulfuric acid by slowly adding one to the other in a 1000-mL beaker. Place the beaker into a salt-ice bath during the mixing so it may cool, allow the temperature to drop below 10 °C after mixing. You can keep the cold acid in the salt-ice bath or you can transfer the acid mix into a round-bottomed 1000-mL Florence flask for better heat dispersion. In either case, prepare a fresh salt-ice bath. Because of the possibility of friction, standard stirring methods are not advised. Instead, use an aquarium pump to blow air into the acids as a means to cool and stir them. Regulate the air flow so the acid is being well stirred yet not spattering out. Using a buret suspended above the flask, very slowly add drop by drop 112 mL of glycerol that has been previously cooled to 15 °C. Carefully monitor the temperature of the reaction at all times, the temperature must stay below 20 °C, preferably below 15 °C for extra safety. If at any time the temperature goes near this, stop adding glycerin until it cools. You can use the rate of addition to control the temperature. If the temperature ever rises above 20 °C it is ruined as no more nitro will be made and you are in great danger of the existing nitro detonating. If the temperature goes above 30 °C, there is a sudden rise in temperature, or a red gas is noticed, DUMP IT INTO COLD WATER IMMEDIATELY!. Keep a bucket of ice water on hand for this task. After adding all of the glycerin, allow the temperature to drop to 15 °C and sit for 15 minutes. Carefully pour the reaction mix into a large beaker containing an equal volume of room temperature water. Add this mix to a separatory funnel and allow the nitroglycerin to settle out, it will form a layer on the bottom of the funnel. Drain off the nitro layer and keep the acid waste layer for further extraction. Place the nitro back into a clean separatory funnel and add plenty of 38-45 °C water, mix, then separate. Wash the nitro again, then wash with a warm 4% sodium carbonate solution. Wash with warm water three more times. Give it a final wash of concentrated sodium chloride solution, and let it sit one day before separating the layers. Separate and check the nitro for acidity with litmus paper. If it is still acidic keep washing. It must be neutral or it will explode. Dry the neutral nitro over sulfuric acid in a desiccator, this may take several days. You will need a graduated cylinder for measuring liquids, and a thermometer to monitor the temperature.
To extract any nitro that may still be in the waste acid, first neutralize the acid with sodium carbonate solution. Next add an equal volume of chloroform to the neutral waste acid. Mix well then place it into the separatory funnel. Remove the bottom nitro layer and let it stand in the open for one day so the chloroform may evaporate. Add this nitro to the washing process above.
One unit of glycerol will yield about 2.5 of nitro. Exposure to nitroglycerine will cause severe headaches. Keep it cool, the warmer it is the more sensitive it is to detonation. Frozen nitro can not be detonated therefore it is stable BUT partially frozen nitro is extra sensitive! Although nitroglycerin is very dangerous when confined, it is merely flammable when spread out in the open air. Nitroglycerin can be destroyed by boiling in a solution of potassium or sodium hydroxide and ethyl alcohol.
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