Hexamethylene triperoxide diamine

Hexamethylene triperoxide diamine (HMTD) is a high explosive organic compound. The theorized structure lent itself well to acting as an initiating, or primary explosive. While still quite sensitive to shock and friction, it was relatively stable compared to other initiating explosives of the time, such as mercury fulminate, and proved to be relatively inexpensive and easy to synthesise. As such, it was quickly taken up as a primary explosive in mining applications. However, it has since been superseded by even more stable compounds such as tetryl.

Preparation and structure

First synthesised in 1885 by Legler, HMTD may be prepared by the reaction of an aqueous solution of hydrogen peroxide and hexamine in the presence of citric acid or dilute sulfuric acid as a catalyst.

The molecule adopts a cage-like structure.

Properties as an explosive

No peroxide has found practical use as an explosive as a consequence of the weak oxygen-oxygen bond, which leads to poor thermal and chemical stability and a high sensitivity to shock (physical impact). Like other organic peroxides such as acetone peroxide, HMTD is unstable and detonates upon shock, friction, and heat. It is, however, less unstable than many other peroxides under normal conditions; exposure to ultraviolet light increases its sensitivity. It also reacts with most common metals, which can lead to detonation. HMTD is chemically very stable when pure (free of acids, bases, and metal ions) and does not quickly sublime like its acetone counterparts.