|Name||Glyceroltrinitrat (Trinitroglycerol; 1.2.3.Trinitroglycerol)|
|Other names||Propan-1,2,3-trioltrinitrat, nitroglycerin, Glyceryltrinitrat, "Nobels Blasting oil|
|Short description||colorless liquid|
|Mol mass||227,09 g/mol|
|State of aggregation||liquid|
|Density||1,5939 g/cm (15 "°C)|
|Melting point||depending upon isomer 2.8 "°C or 13.5 "°C|
|Boiling point||290 "°C|
|Steam pressure||Pa (x "°C)|
|Solubility||badly in water, well in acetone, methanol, Diethylether|
|R and S-sentences||R: 26/27/28-3-33S: 1/2 33 35 36/37 45|
|As far as possible and common, SI-UNITs are used. If not differently notes, the indicated data apply with standard conditions.|
Glycerintrinitrat is a well-known explosive and has the sum formula C3H5 (ONO2) 3. The common designation Nitroglycerin is in accordance with IUPAC nomenclature misleading, since the prefix Nitro refers to a nitrogen-bound NO2-Gruppe. In the Glycerintrinitrat however the alkyl residue is bound over a verb-moving oxygen atom to the nitrogen, why it concerns a tri ester of the nitric acid. Still more accurately than Glycerintrinitrat the designation would be therefore Glycerintris (nitrate), which points out prefix of trichloroethylene that it does not act with the acid residue around a condensate out of three molecules HNO3 was verestert, but three times with one molecule each.
Glycerintrinitrat is with standard conditions a colorless, odorless and badly water-soluble liquid. It has a taste and already the income of a small quantity of Nitroglycerin leads to headache. The melting point is to 13.5 depending upon isomer about 2,8 "°C or "°C. Because of the oxygen surplus Glycerintrinitrat is a rather unstable connection, which can be already brought to exotherms reaction by a small activation energy to one strongly. The liquid is converted in extremely short time completely into gaseous products, which leads to a substantial volumetric expansion (explosion; Computation of the mass of gas with the explosion of 1 mol of Nitroglycerin here).
Glycerintrinitrat is used as explosive. Because of the strong impact and vibration sensitivity the handling is however rather difficult. Alfred Nobel succeeded it to store Glycerintrinitrat in Kieselgur. The developing dynamite is simpler to use. Gylcerintrinitrat than an explosive component became later because of its high freezing point nearly completely by Nitroglykol (Ethylenglykoldinitrat; EGDN) replaces, which freezes only with -22 "°C. Glycerintrinitrat is against it today still another important component of many propellant powders.
In the Metallografie Glycerintrinitrat is used in combination with other chemicals than etching agents for materials.
At school there is one percent solution in ethanol (ethyl alcohol). This solution may be used by pupils of the secondary school I.
In the medicine it is used because of its container-extending effect under the name Glyceroltrinitrat as means with angina Pectoris, heart insufficiency and also as acute means with a cardiac infarct.
Although Alfred Nobel often suffered from angina Pectoris, it rejected a treatment with Glycerolnitrat vehement: he got headache by steams in his factory.
Glycerintrinitrat is made by the Veresterung of the three hydroxyl groups by water-free Glycerin with a mixture of nitric acid and sulfuric acid, the in such a way specified.
One differentiates between intermittent and continuous manufacturing processes.
The intermittent procedures manufacture nitroglycerin chargenweise:
"Cold method": The is cooled up to 15 "°C. It is added glycerin in small quantities and cooled and agitated meanwhile well. The temperature rises and may not not exceed 30 "°C. Starting from 32 "°C threatens auto+catalytic decomposition of the formed Glycerintrinitrat, which can lead because of the heat development to the explosion. If the glycerin is attached, the temperature under 25 must sink "°C. The reaction is terminated after approximately 15 minutes. Separated nitroglycerin is washed and carefully from all acid residues by means of caustic soda solution (sodium hydroxide; NaOH) releases. Also the caustic soda solution is for its part removed with water and the Glycerintrinitrat is finally dried. Only the well washed and neutralized Glycerintrinitrat is stable.
"Method" snaps: and glycerin are precooled merged and cast in in water. The formed Glycerintrinitrat sinks to soil, can be taken off and washed. The yield is low. This method was used occasionally by Alfred Nobel.
"2-step method": Glycerin is loosened in sulfuric acid. To the solution is given, whereby the temperature may not exceed 22 "°C. After several hours nitroglycerin at the surface separates. Advantage of the method is the smaller heat development compared with the other methods. Disadvantage is the long contact of the Glycerintrinitrat with the acids, which increase the probability of dangerous decomposition.
In order to keep and the productivity increase the Glycerintrinitratmengen in the individual processing levels as small as possible, continuous manufacturing processes were developed. In the simplest case and glycerin are given continuously by a cooled pipe. The most modern procedures work according to the injector principle. The injector is developed like a water-operated vacuum pump. Instead of the water flows by the injector. With the negative pressure glycerin is sucked in and swirled in the acid jet. The temperature is with approximately 70 "°C.
Because of the high danger of injury by explosions experts recommend to manufacture Glycerintrinitrat only in particularly secured laboratories and to keep the legal regulations exactly. Also with the synthesis of small quantities a large danger of heavy, also fatal injuries exists. Only one drop can already destroy the laboratory instruments.
4 C3H5 (ONO2) 3 12 CO2 + 10 H2O + 6 N2 + CO2
In the year 1847 the Turiner physician Ascanio Sobrero manufactures for the first time Nitroglycerin.