RDX Cyclotrimethylenetrinitramine

The simplest method of preparing RDX (7.9) is by adding hexamethylenetetramine to excess concentrated nitric acid at 25 °C and warming to 55 °C. RDX is precipitated with cold water and the mixture is then boiled to remove any soluble impurities. Purification of RDX is carried out by recrystallization from acetone. 

The chemistry of the preparation of RDX is highly complex. When hexamethylenetetramine is reacted with nitric acid, hexamethylenetetramine dinitrate is formed which is then nitrated to form an intermediate Compound T as shown in Reaction 7.10 (overleaf). 

Further nitrolysis of Compound I results in the formation of RDX via two other intermediate compounds as shown in Reaction 7.11. 

Other manufacturing techniques include the SH-process invented by Schnurr, the K-process patented by Knoffler, the W-process patented by Wolfram, the E-process patented by Erbele, and the KA-method invented by Knoffler and Apel and also Bachmann. 

The SH-process involves continuous nitration of hexamethylenetetramine by concentrated nitric acid, with the production of nitrous gas. The RDX is filtered from the residual acid and stabilized by boiling in water under pressure and purified by recrystallization from acetone. 

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An interesting class of molecular crystals are those that easily decompose exothermally i.e., explosive crystals. Some form from small molecules such as lead azide [Pb(N3)2] and ammonium perchlorate (NH4CIO4) and others form moderately large molecules such as RDX (cyclotrimethylenetrinitramine), and PETN (pentaerythritol-tetranitrate). 

RDX, Cyclotrimethylenetrinitramine, Hexogene or Cyclonite). Its prepn, props and analytical procedures are described by Belgrano (Ref 31, pp 255-59)... 

Between World War I and II, TNT replaced picric acid as the explosive of choice in munitions. It was also mixed with other compounds to produce more powerful explosives with unique characteristics. Amatol is a mixture containing between 40% and 80% ammonium nitrate and TNT. Pentolite is a mixture of PETN (pentaerythritol tetranitrate) and TNT. Another common explosive mixture is RDX (cyclotrimethylenetrinitramine) and TNT. RDX is an abbreviation for Royal Demolition Explosive. 

Abbreviation used in Table B AN-Ammonium nitrate AmmPic-Ammonium picrate bk-black brn-brown EDD-Ethylendiamine dinitrate EDNA-Ethylenedinitramine grn-green HNDPhA -Hexanitrodiphenyiamine ppt-precipitate RDX - Cyclotrimethylenetrinitramine soln- solution soly - solubility TNAns -... 

Boosters such as RDX (cyclotrimethylenetrinitramine, melting point 204°C, density 1.80), PETN(pentaerythritoltetranitrate, melting point 143°C, density 1.78), and TETRYL (2,4,6-trinitrophenyl methyl nitramine, melting point 129.5°C, density 1.73) are extremely important chemicals. 

Although the P-4 primer was only in use for approximately 1 year, it was further improved in 1961 by coating the stabilized red phosphorus with PETN, RDX (cyclotrimethylenetrinitramine), or TNT giving the following primer mix ... 

Compounds not soluble in a supercritical fluid can be recrystallized in a process termed gas antisolvent (GAS) recrystailization. The process was first applied to the recrystailization of an explosive, RDX (cyclotrimethylenetrinitramine) into... 

RDX (cyclotrimethylenetrinitramine). Royal Demolition Explosive, hexogen, or cyclonite... 

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