Guanidine nitrate is the chemical compound with the formula (NH₂)₃O₃. It is a colorless, water-soluble salt. It is produced on a large scale and finds use as precursor for

nitroguanidine Nitroguanidine - sometimes abbreviated NGu - is a colorless, crystalline solid that melts at 257 °C and decomposes at 254 °C. Nitroguanidine is an extremely insensitive but powerful high explosive. Wetting it with > 20 wt.-% water effe ...

, fuel in pyrotechnics and

gas generator A gas generator is a device for generating gas. A gas generator may create gas by a chemical reaction or from a solid or liquid source, when storing a pressurized gas is undesirable or impractical. The term often refers to a device that uses a ...

s. Its correct name is guanidinium nitrate, but the colloquial term guanidine nitrate is widely used.

Production and properties

Although it is the

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

formed by neutralizing

guanidine Guanidine is the compound with the formula HNC(NH2)2. It is a colourless solid that dissolves in polar solvents. It is a strong base that is used in the production of plastics and explosives. It is found in urine predominantly in patients experie ...

with

nitric acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...

, guanidine nitrate is produced industrially by the reaction of

dicyandiamide 2-Cyanoguanidine is a nitrile derived from guanidine. It is a dimer of cyanamide, from which it can be prepared. 2-Cyanoguanidine is a colourless solid that is soluble in water, acetone, and alcohol, but not nonpolar organic solvents. Production ...

(or calcium salt) and

ammonium nitrate Ammonium nitrate is a chemical compound with the chemical formula . It is a white crystalline salt consisting of ions of ammonium and nitrate. It is highly soluble in water and hygroscopic as a solid, although it does not form hydrates. It is ...

.Thomas Güthner, Bernd Mertschenk and Bernd Schulz "Guanidine and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. It has been used as a

monopropellant Monopropellants are propellants consisting of chemicals that release energy through exothermic chemical decomposition. The molecular bond energy of the monopropellant is released usually through use of a catalyst. This can be contrasted with bipro ...

in the Jetex engine for

model airplane A model aircraft is a small unmanned aircraft. Many are replicas of real aircraft. Model aircraft are divided into two basic groups: flying and non-flying. Non-flying models are also termed static, display, or shelf models. Aircraft manufactur ...

s. It is attractive because it has a high gas output and low flame temperature. It has a relatively high monopropellant

specific impulse Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is ...

of 177 seconds (1.7 kN·s/kg).1000 lbf/in² (700 kPa) chamber pressure, 14.7 lbf/in² (101 kPa) exit pressure, shifting equilibrium theoretical performance. Guanidine nitrate's explosive decomposition is given by the following equation: H₆N₄CO_{3 ''(s)''} → 3 H₂O_''(g)'' + 2 N_{2 ''(g)''} + C_''(s)''

Applications

Guanidine nitrate is used as the gas generator in automobile airbags. It is less toxic than the mixture used in older airbags of sodium azide,

potassium nitrate Potassium nitrate is a chemical compound with the chemical formula . This alkali metal nitrate salt is also known as Indian saltpetre (large deposits of which were historically mined in India). It is an ionic salt of potassium ions K+ and nitr ...

and

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...

(NaN₃, KNO₃, and SiO₂), and it is less explosive and sensitive to moisture compared to the very cheap

(NH₄NO₃).

Safety

The compound is a hazardous substance, being an explosive and containing an oxidant (nitrate). It is also harmful to the eyes, skin, and respiratory tract.

Notes

External links

*Jetex
Propellants
*PhysChem

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