TEX (chemical name 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo .5.0.0^5,9.0^3,11dodecane) is a dense (ρ = 1.985 g cm⁻³)

nitramine Nitramide or nitroamine is a chemical compound with the molecular formula . Substitution reaction, Substituted derivatives are termed nitramides or nitroamines as well. Organyl derivatives of nitramide, and , are widely used as explosives: exam ...

high explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...

, that derives from the very powerful and sensitive high explosive CL-20. Though related to CL-20 in that is shares the same cage structure, TEX is more easily synthesized in good yield from inexpensive starting materials. Unlike CL-20, TEX is friction insensitive, bears a low impact sensitivity, and possesses a very low shock sensitivity and large critical diameter, making it an interesting explosive filler for insensitive munitions. Its systematic name, 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo .5.0.0^5,9.0^3,11dodecane derives from its tetracyclic structure.

Synthesis and production

Unlike CL-20, which requires a cumbersome and even costly procedure, TEX is obtained in moderate yield (40 wt.-%) in a one-pot synthesis from 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine (DFTHP) and mixed acid ( H₂SO₄/ HNO₃). The DFTHP undergoes proton-catalyzed hydrolysis and yields

glyoxal Glyoxal is an organic compound with the chemical formula OCHCHO. It is the smallest dialdehyde (a compound with two aldehyde groups). It is a crystalline solid, white at low temperatures and yellow near the melting point (15 °C). The liquid ...

which reacts as with an intermediate to give TEX. : TEX-formation

Performance

Based on the Kamlet-Jacobs method, the formal idealistic detonation of TEX :C₆H₆N₄O₈ → 3 H₂O_(g) + 2CO₂ + CO + 3 C_(gr) + 2 N₂ at ambient temperature and density of TEX (1.985 g/cm³) yields a detonation velocity of 8170 m/s and a CJ pressure of 31.4 GPa. Calculations with advanced computational algorithms like EXPLO and CHEETAH predict even higher detonation velocity but about similar values for the detonation pressure, definitely superseding insensitive high explosive NTO. Experimental determination with plastic bonded formulations at high theoretical maximum density exceed the predicted detonation pressures but fall a little short with regards to the detonation velocity if the charge diameter is below 90 mm.

Sensitivity

TEX is not friction sensitive and requires some 40 Joules energy to react in the BAM impact tester. In the autoignition test it yields a mild burn response at 252 °C onset temperature. TEX is also mildly shock sensitive in the Large Scale Gap Test (LSGT).

Toxicity

TEX has a similar water solubility as

RDX RDX (Research Department Explosive or Royal Demolition Explosive) or hexogen, among other names, is an organic compound with the formula (CH2N2O2)3. It is white, odorless, and tasteless, widely used as an explosive. Chemically, it is classified ...

and hence will be equally mobile in soil and groundwater. However, in comparison to insensitive explosive NTO, which is highly soluble in water (16 g/L), it should pose a lower level of concern when considering the environmental effects of unexploded or partially exploded charges. Preliminary investigation of the effects of TEX on daphnia and cell cultures show slightly lower toxicity than RDX.

Application

Though known since 1990, TEX is still an experimental explosive. However, given its large critical diameter and low shock sensitivity, it is an ideal candidate for insensitive large-calibre ammunition such as

general-purpose bomb A general-purpose bomb is an air-dropped bomb intended as a compromise between blast damage, penetration, and fragmentation in explosive effect. They are designed to be effective against enemy troops, vehicles, and buildings. Characteristics ...

artillery shell A shell, in a modern military context, is a projectile whose payload contains an explosive, incendiary device, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military ...

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...

es and

depth charge A depth charge is an anti-submarine warfare (ASW) weapon designed to destroy submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited ...

References