Ammonium perchlorate

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Ammonium perchlorate
Ammonium perchlorate
IUPAC name
Other names AP
Identifiers
CAS number [7790-98-9]
EC number 232-235-1
UN number 1442
RTECS number SC7520000
Properties
Molecular formula NH4ClO4
Molar mass 117.49 g/mol
Appearance white granular
Density 1.95 g/cm3
Melting point

Exothermic decomposition before melting at >200 °C[1]

Solubility in water 11.56 g/100 mL (0 °C)
20.85 g/100 mL (20 °C)
57.01 g/100 mL (100 °C)
Solubility soluble in methanol
partially soluble in acetone
insoluble in ether
Structure
Crystal structure Orthorhombic (< 513 K)
Cubic (> 513 K)
Hazards
MSDS External MSDS
EU Index 017-009-00-0
EU classification Oxidant (O)
R-phrases R9, R44
S-phrases (S2), S14, S16, S27, S36/37
NFPA 704
1
2
4
OX
Related compounds
Other anions Ammonium chlorate
Ammonium chloride
Other cations Potassium perchlorate
Sodium perchlorate
Lithium perchlorate
Related compounds Perchloric acid
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox references

Ammonium perchlorate (AP) is a chemical compound with the formula NH4ClO4. It is the salt of ammonia and perchloric acid. Like other perchlorates, it is a powerful oxidizer.

It is produced by reaction between ammonia and perchloric acid, or by double decomposition between an ammonium salt and sodium perchlorate.

It crystallises in colorless rhombohedra with a relative density of 1.95. Like most ammonium salts, it decomposes before melting. Mild heating results in chlorine, nitrogen, oxygen and water, while strong heating may lead to explosions.

The combustion of such compound is quite complex and is widely studied in literature. Ammonium perchlorate crystals decompose before melting, even though a thin liquid layer has been observed on crystal surface during high pressure combustion processes.[2]

The gaseous decomposition products are in general ammonia- and chlorine-based and can react together generating a thin premixed flame very close to the crystal surface. Pure crystals cannot sustain a flame below the pressure of 20 bar (2 MPa). Nevertheless, the material is considered hazardous if ground under 15 micrometres. When AP is mixed with a fuel (like a metal powder or mixed with a polymeric binder) it can generate self-sustained combustion also far under atmospheric pressure.

It is an important oxidizer used in solid rocket propellants known as Ammonium perchlorate composite propellants (APCP). Uses include the Space Shuttle Solid Rocket Boosters, manufactured by Alliant Techsystems (ATK), as well as many other solid rockets including some fireworks, amateur and hobby high powered rockets, and larger rockets used for space launch and military purposes.

[edit] See also

[edit] References

  1. ^ Liu, L.; Li, F.; Tan, L.; Ming, L.; Yi, Y. (2004), "Effects of Nanometer Ni, Cu, Al and NiCu Powders on the Thermal Decomposition of Ammonium Perchlorate", Propellant, Explosives, Pyrotechnics 29: 34–38 
  2. ^ T. L. Boggs, Deflagration Rate, Surface Structure and Subsurface Profile of Self-Deflagrating Single Crystals of Ammonium Perchlorate. AIAA Journal, 8(5), 1970, pp. 867--873
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