| IUPAC name
| Other names
Her Majesty's Explosive
High Melting Explosive
High-velocity Military Explosive
|Molar mass||296.155 g/mol|
|Appearance||White colorless solid|
|Density||1.91 g/cm3 (25 °C)|
|Melting point||276–286 °C (529–547 °F; 549–559 K)|
|Boiling point||287 °C (549 °F; 560 K) Decomposes|
| 0.000334 g/100 ml (20 °C)|
0.000446 g/100 ml (25 °C)
|Solubility|| Solvates in DMF, NMP|
Soluble in butyrolactone, dimethyl sulfoxide
Slightly soluble in acetone, acetonitrile, cyclohexanone
|Solubility in acetone|| 2.8 g/100 ml (25 °C)|
4.2 g/100 ml (56 °C)
|Solubility in acetonitrile|| 2 g/100 ml (25 °C)|
7.3 g/100 ml (82 °C)
|Solubility in butyrolactone|| 12 g/100 ml (25 °C)|
20 g/100 ml (60 °C)
35 g/100 ml (98 °C)
|Solubility in cyclohexanone|| 1 g/100 ml (25 °C)|
8.9 g/100 ml (98 °C)
|Solubility in dimethyl sulfoxide|| 57 g/100 ml (25 °C)|
68 g/100 ml (60 °C)
89 g/100 ml (98 °C)
|Vapor pressure||2.41·10-8 mmHg at 25°C|
|Safety data sheet||Multihost IT|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
HMX, also called octogen, is a powerful and relatively insensitive nitroamine high explosive, chemically related to RDX.
Like RDX, the compound's name is the subject of much speculation, having been variously listed as High Melting Explosive, Her Majesty's Explosive, High-velocity Military Explosive or High-Molecular-weight RDX.
HMX will decompose if heated and can explode if a basting cap is used.
HMX is a white solid, odorless, practically insoluble in water and poorly soluble in most common organic solvents, but has good solubility in DMSO and butyrolactone.
Because of its high molecular weight, HMX is one of the most potent chemical explosives manufactured commercially. It has a low shock and friction sensitivity, and cannot be detonated by igniting it, detonation requiring a blasting cap. HMX has a detonation velocity of 9,100 m/s and a R.E. factor of 1.7.
HMX, being a high explosive is not sold and can only be acquired by the military or research institutions.
Nitrating hexamine with concentrated nitric acid in the presence of ammonium nitrate, boron trifluoride, diethyl ether, acetic anhydride in acetic acid will also give HMX. The process takes around 75 min for completion at 44 °C, and gives an yield of around 16-17%.
- Make blasting charges
At present, the information needed to determine if HMX causes cancer is insufficient. Due to the lack of information, EPA has determined that HMX is not classifiable as to its human carcinogenicity.
The available data on the effects on human health of exposure to HMX are limited. HMX causes CNS effects similar to those of RDX, but at considerably higher doses.
HMX is best kept in plastic or wooden containers. Do not store it for long.
Controlled incineration should suffice.
Biodegradation using microorganisms has been successfully tried.
- Liang, Lixuan; Cao, Dan; Song, Jinhong; Huang, Haifeng; Wang, Kai; Bian, Chengming; Dong, Xiao; Zhou, Zhiming; Journal of Materials Chemistry A; vol. 1; nb. 31; (2013); p. 8857 - 8865
- Monteil-Rivera, Fanny; Groom, Carl; Hawari, Jalal; Environmental Science and Technology; vol. 37; nb. 17; (2003); p. 3878 - 3884
- Huang, Chi-Yu; Mah, Robert A.; Que Hee, Shane S.; Journal of Labelled Compounds and Radiopharmaceuticals; vol. 41; nb. 5; (1998); p. 377 - 385