chemistry of 1, 3, 5-trinitroperhydro-1, 3, 5-triazine - Internationale ...

CHEMISTRY OF 1, 3, 5-TRINITROPERHYDRO-1, 3, 5-TRIAZINE 

ABSTRACT 

RDX, an initialism for Research Department Explosive, is an explosive 

nitroamine widely used in military and industrial applications. It is also 

known less commonly as cyclonite, hexogen (particularly in German and 

German-influenced languages) and T4. Its chemical name is 

cyclotrimethylenetrinitramine; variants include cyclotrimethylene- 

trinitramine and cyclotrimethylene trinitaramine. In its pure, synthesized 

state RDX is a white, crystalline solid. As an explosive, it is usually used in 

mixtures with other explosives and plasticizers, phlegmatizers or 

desensitizers. It is stable in storage and is considered one of the most 

powerful and brisant of the military high explosives. 

Keywords: RDX, PBX, Cyclonite, Cyclotol, Hexamine, TNT, Hexogen T4, 

HBX, H-6, Torpex, PETN, PBXN. 

RDX, abbreviation of Research Department eXplosive 

or Royal Demolition eXplosive, formally 

cyclotrimethylenetrinitramine, also called cyclonite, 

hexogen, or T4, powerful explosive, discovered by 

Georg Friedrich Henning of Germany and patented in 

1898 but not used until World War II, when most of 

the warring powers introduced it. Relatively safe and 

inexpensive to manufacture, RDX was produced on a 

large scale in the United States by a secret process 

developed in the United States and Canada. The name 

RDX was coined by the British. This name was 

accepted in the United States, although the name 

cyclonite was also commonly used there. The Germans 

called it hexogen, and the Italians called it T4. RDX is a 

hard, white crystalline solid, insoluble in water and 

Address for correspondence 

Prof. Dr. Dhrubo Jyoti Sen 

Department of Pharmaceutical Chemistry, Shri 

Sarvajanik Pharmacy College, Gujarat Technological 

University, Arvind Baug, Mehsana-384001, Gujarat, 

India. 

E-mail: dhrubosen69@yahoo.com 

INTERNATIONALE PHARMACEUTICA SCIENCIA 

| April-June 2011 | Vol. 1 | Issue 2 | 

Available online http://www.ipharmsciencia.com 

ISSN 2231-5896 

©2011 IPS 

only slightly soluble in some other solvents. Sensitive 

to percussion, its principal nonmilitary use is in 

blasting caps. It is often mixed with other substances 

to decrease its sensitivity (Bachmann et al., 1949). 1 

NO 2 

N 

N N 

O2N NO2 REVIEW ARTICLE 

Charoo S. Garg, Jimit S. Patel, 

Kiran M. Patel, Jignesh B. Patel, 

Divyang H. Shah and Prof. Dr. 

Dhrubo Jyoti Sen 

Department of Pharmaceutical 

Chemistry, Shri Sarvajanik 

Pharmacy College, Gujarat 

Technological University, 

Arvind Baug, Mehsana-384001, 

Gujarat, India 

Date of Submission: 04-05-2011 

Date of Acceptance: 15-05-2011 

Conflict of interest: Nil 

Source of support: None 

11 Internationale Pharmaceutica Sciencia Apr-Jun 2011 Vol 1 Issue 2

Chemical name 1,3,5-trinitro-1,3,5-triazinane, 1,3,5-Trinitroperhydro-1,3,5-triazine, 1,3,5-Trinitro-1,3,5triazacyclohexane, 

1,3,5-Trinitrohexahydro-s-triazine, cyclonite, hexogen, 

Cyclotrimethylenetrinitramine 

Molecular formula C3H6N6O6 

Formula Weight 222.11 gm 

Molar mass 222.12 g mol −1 

Composition C(16.22%) H(2.72%) N(37.84%) O(43.22%) 

Molar Refractivity 43.65 ± 0.4 cm 3 

Molar Volume 117.0 ± 5.0 cm 3 

Parachor 376.0 ± 6.0 cm 3 

Index of Refraction 1.668 ± 0.03 

Surface Tension 106.6 ± 5.0 dyne/cm 

Density 1.89 ± 0.1 g/cm 3 

Polarizability 17.30 ± 0.5 10 -24 cm 3 

Monoisotopic Mass 222.034882 Da 

Nominal Mass 222 Da 

Average Mass 222.1163 Da 

CAS number 121-82-4 

PubChem 8490 

ChemSpider 8177 

UN number 0072, 0391, 0483 

Appearance Colorless crystals 

Melting point 205.5 °C, 479 K, 402 °F 

Boiling point 234 °C, 507 K, 453 °F 

Shock sensitivity Low 

Friction sensitivity Low 

Explosive velocity 8750 m/s 

RE factor 1.60 

Name 

Prof. Dr. Dhrubo Jyoti Sen et al: Chemistry of 1, 3, 5-Trinitroperhydro-1, 3, 5-Triazine 

RDX is also known, but less commonly, as cyclonite, 

hexogen (particularly in German and German- 

influenced languages), T4 and chemically as 

cyclotrimethylenetrinitramine. Tenney L Davis, 

writing in the USA in 1943, stated it was generally 

known in the USA as cyclonite; the Germans called it 

Hexogen, the Italians T4. In the 1930s, the Royal 

Arsenal, Woolwich, started investigating cyclonite as 

an explosive to use against German U-boats that were 

being built with thicker hulls. Britain wanted an 

explosive that was more powerful than TNT. For 

security reasons, Britain termed cyclonite as 

"Research Department Explosive" (R. D. X.). The term 

RDX appeared in the United States in 1946, but the 

name RDX is given without explanation. The first 

public reference in the United Kingdom to the name 

RDX, or R.D.X. to use the official title, appeared in 

1948; its authors were the Managing Chemist, ROF 

Bridgwater, the Chemical Research and Development 

Department, Woolwich, and the Director of Royal 

Ordnance Factories, Explosives; again, it was referred 

to as simply RDX (Gilman et al., 1953). 2 

Usage 

RDX was widely used during World War II, often in 

explosive mixtures with TNT such as Torpex, 

Composition B, Cyclotols, and H6. RDX was used in 

one of the first plastic explosives. RDX is believed to 

have been used in many bomb plots including 

terrorist plots. The bombs used in the "Dambusters 

Raid" contained 6,600 pounds of Torpex. 

RDX forms the base for a number of common military 

explosives: 

Internationale Pharmaceutica Sciencia Apr-Jun 2011 Vol 1 Issue 2 

• Composition A: Granular explosive consisting of 

RDX and plasticizing wax. Such as, composition A- 

5 (RDX coated with 1.5% stearic acid) and 

composition A-3 (91% RDX coated with 9% wax) 

12

• Composition B: Castable mixtures of RDX and 

TNT 

• Composition C: The original composition C was 

used in World War II, but there have been 

subsequent variations including C-2, C-3, and C-4. 

C-4 consists of RDX (91%), a plasticizer (which can 

be dioctyl adipate {DOA}, diethylhexyl, or dioctyl 

sebacate) (5.3%), a binder, which is usually 

polyisobutylene (2.1%), SAE 10 non-detergent 

motor oil (1.6%). 

• Composition CH-6: 97.5% RDX, 1.5% calcium 

stearate, 0.5% polyisobutylene, and 0.5% graphite. 

• Cyclotol: Cyclotol is an explosive consisting of 

castable mixtures of RDX and TNT. 

It is related to the more common Composition B, 

which is roughly 60% RDX and 40% TNT; various 

compositions of Cyclotol contain from 65% to 80% 

RDX. Typical ranges are from 60/40 to 80/20 

RDX/TNT, with the most common being 70/30, 

while the military mostly uses 77/23 optimized in 

warheads. Cyclotol is not commonly used, but was 

reportedly the main explosive used in at least some 

models of US Nuclear weapon. Sublette lists 

Cyclotol as the explosive in the US B28 nuclear 

bomb and possibly related weapons that used the 

common Python primary - W34, W28, W40, and 

W49. It was also used in the B53 nuclear bomb and 

associated W53 warhead. 

• HBX: Castable mixtures of RDX, TNT, powdered 

aluminium, and D-2 wax with calcium chloride 

• H-6: Castable mixture of RDX, TNT, powdered 

aluminum, and paraffin wax 


N 

N 

N 

N 

1,3,5,7-tetraazatricyclo[3.3.1.1 3,7 ]decane 

Hexamine 

HNO 3 

SCHEME 

NO 2 

N 

• Semtex: (Trade name): Plastic demolition 

explosives containing RDX and PETN as major 

energetic components 

• Torpex: 42% RDX, 40% TNT and 18% powdered 

aluminium 

• PBX: RDX is also used as a major component of 

many polymer-bonded explosives (PBX). RDX- 

based PBX's typically consist of RDX and a 

polymer/co-polymer binder. Examples of RDX- 

based PBX formulations include, but are not 

limited to: PBX-9007, PBX-9010, PBX-9205, PBX- 

9407, PBX-9604, PBXN-106, PBXN-3, PBXN-6, 

PBXN-10, PBXN-201, PBX-0280, PBX Type I, 

PBXC-116, PBXAF-108, etc. 

Outside of military applications, RDX is also used in 

controlled demolition to raze structures. The 

demolition of the Jamestown Bridge in the U.S. state 

of Rhode Island is one example where RDX shaped 

charges were used to remove the span (Hale et al., 

1925). 3 

Properties 

The velocity of detonation of RDX at a density of 1.76 

g/cm³ is 8750 m/s. 

It is a colourless solid, of maximum theoretical 

density 1.82 g/cm³. It is obtained by reacting 

concentrated nitric acid with hexamine (Luo et al., 

2002). 4 

N N 

O2N NO2 1,3,5-trinitro-1,3,5-triazinane 

RDX 

(CH2)6N4 + 10HNO3 → (CH2-N-NO2)3 + 

3CH2(ONO2)2 + NH4NO3 + 3H2O 

ONO 2 

ONO 2 

+ 

+ NH 4 NO 3 H 2 O 

methylene dinitrate 

13 Internationale Pharmaceutica Sciencia Apr-Jun 2011 Vol 1 Issue 2 

+

It is a heterocycle and has the molecular shape of a 

ring. It starts to decompose at about 170°C and melts 

at 204°C. Its structural formula is: hexahydro-1,3,5- 

trinitro-1,3,5-triazine or (CH2-N-NO2)3. 

At room temperature, it is very stable. It burns rather 

than explodes and detonates only with a detonator, 

being unaffected even by small arms fire. It is less 

sensitive than pentaerythritol tetranitrate (PETN). 

However, it is very sensitive when crystallized, below 

−4°C. Under normal conditions, RDX has a figure of 

insensitivity of exactly 80 (RDX defines the reference 

point.). 

RDX sublimes in vacuum, which limits its use in 

pyrotechnic fasteners for spacecraft. 

RDX when exploded in air has about 1.5 times the 

explosive power of TNT per unit weight and about 2.0 

times per unit volume. 

History 

RDX was used by both sides in World War II. The U.S. 

produced about 15,000 long tons (15,000 t) per 

month during WW II and Germany about 7,000 long 

tons (7,100 t) per month. RDX had the major 

advantages of possessing greater explosive power than 

TNT used in the First World War, and requiring no 

additional raw materials for its manufacture 

(Simmons et al., 1948). 5,6 

Germany 


The discovery of RDX dates from 1898 when Georg 

Friedrich Henning obtained a German patent (patent 

No. 104280) for its manufacture, by nitrating 

hexamine nitrate (hexamethylenetetramine nitrate) 

with concentrated nitric acid. In this 1898 patent, its 

properties as a medical compound were mentioned; 

however, three further German patents obtained by 

Henning in 1916 proposed its use in smokeless 

propellants. The German military started 

investigating its use in 1920 and referred to it as 

hexogen. Research and development findings were 

not published further until Edmund von Herz, 

described as an Austrian and later a German citizen, 

obtained a British patent in 1921 and a U.S. patent in 

1922. Both patent claims were initiated in Austria; 

and described the manufacture of RDX by nitrating 

hexamethylenetetramine. The British patent claims 

included the manufacture of RDX by nitration, its use 

with or without other explosives, and its use as a 

bursting charge and as a initiator. The U.S. patent 

claim was for the use of a hollow explosive device 

containing RDX and a detonator cap containing RDX. 

In the 1930s, Germany developed improved 

production methods. 

During the Second World War, Germany used the 

code names W Salt, SH Salt, K-method, the E-method 

and the KA-method. These represented the names of 

the developers of the various chemical processes used 

to prepare RDX. The W-method was developed by 

Wolfram in 1934 and gave RDX the code name "W- 

Salz". It used sulphamic acid, formaldehyde and nitric 

acid. SH-Salz (SH salt) was from Schnurr who 

developed a batch-process in 1937–38 based on 

nitrating hexamine. The K-method was from Knõffler 

and was based on adding ammonium nitrate to the 

hexamine / nitric acid process The E-method was 

developed by Ebele, in Germany, and turned out to be 

identical to the Ross and Schiessler process described 

later. The KA-method was developed by Knöffler, in 

Germany, and turned out to be identical to the 

Bachmann process described later. 

UK 


In the United Kingdom (UK), RDX was manufactured 

from 1933 by the Research Department in a pilot 

plant at the Royal Arsenal in Woolwich, London; a 

larger pilot plant being built at the RGPF Waltham 

Abbey just outside London in 1939. In 1939 a twin- 

unit industrial-scale plant was designed to be installed 

at a new 700 acres (280 ha) site, ROF Bridgwater, 

away from London; and production of RDX started at 

Bridgwater on one unit in August 1941. The ROF 

Bridgwater plant brought in ammonia and methanol 

as raw materials: the methanol was converted to 

formaldehyde and some of the ammonia converted to 

nitric acid, which was concentrated for RDX 

production (Simmons et al., 1948). 5,6 The rest of the 

ammonia was reacted with formaldehyde to produce 

hexamine. The hexamine plant was supplied by 

14

Imperial Chemical Industries; and it incorporated 

some features based on data obtained from the United 

States (U.S.) (Simmons et al., 1948). 5,6 RDX was 

produced by continually adding hexamine and 

concentrated nitric acid to a cooled mixture of 

hexamine and nitric acid in the nitrator (Simmons et 

al., 1948). 5,6 The RDX was purified and processed for 

its intended use; and recovery and reuse of some 

methanol and nitric acid was also carried out. The 

hexamine-nitration and RDX purification plants were 

duplicated (i.e. twin-unit) to provide some insurance 

against loss of production due to fire, explosion or air 

attack. 

The United Kingdom and British Empire were 

fighting without allies against Nazi Germany until the 

middle of 1941 and had to be self-sufficient. At that 

time (1941), the UK had the capacity to produce 

70 long tons (71 t) (160,000 lb) of RDX per week; 

both Canada, an allied country and former self- 

governing dominion of the British Empire, and the 

U.S. were looked upon to supply ammunition and 

explosives, including RDX. By 1942 the Royal Air 

Force's annual requirement was forecast to be 

52,000 long tons (53,000 t) of RDX, much of which 

came from North America (Canada and the U.S.). 

Canada 

A different method of production to the Woolwich 

process was found and used in Canada, possibly at the 

McGill University Department of Chemistry. This was 

based on reacting paraformaldehyde and ammonium 

nitrate in acetic anhydride. A UK patent application 

was made by Robert Walter Schiessler, Pennsylvania 

State College and James Hamilton Ross, at McGill, 

Canada, in May 1942 and the UK patent was issued in 

December 1947. Gilman states that the same method 

of production had been independently discovered by 

Ebele in Germany prior to Schiessler and Ross, but 

that this was not known by the Allies. Urbański 

provides details of five methods of production: this is 

listed as the (German) E-method. 


UK, U.S. and Canadian production and 

development 

At the beginning of the 1940s, the major U.S. 

explosive manufacturers, E. I. du Pont de Nemours & 

Company and Hercules had several decades of 

experience of manufacturing Trinitrotoluene (TNT) 

and had no wish to experiment with new explosives; a 

view also held by the U.S. Army Ordnance, who 

proposed to continue using TNT. RDX had been 

tested by Picatinny Arsenal in 1929 and it was 

regarded as too expensive and too sensitive. The Navy 

proposed to continue using ammonium picrate. In 

contrast, the view that new explosives were 

unnecessary was not shared by the National Defense 

Research Committee (NDRC), who had visited The 

Royal Arsenal, Woolwich. James B. Conant, chairman 

of Division B, wished to involve academic research 

into this area. Conant therefore set up an 

Experimental Explosives Research Laboratory at the 

Bureau of Mines, Bruceton, Pennsylvania using direct 

Office of Scientific Research and Development 

(OSRD) funding. 

In 1941, the UK's Tizard Mission visited the U.S. Army 

and Navy departments and part of the information 

handed over included details of the "Woolwich" 

method of manufacture of RDX and its stabilisation 

by mixing it with beeswax. The UK was asking that the 

U.S. and Canada, combined, supply 220 short tons 

(200 t) (440,000 lb) of RDX per day. A decision was 

taken by William H. P. Blandy, Chief of the Bureau of 

Ordnance to adopt RDX for use in mines and 

torpedoes. Given the immediate need for RDX, the 

U.S. Army Ordnance, at Blandy's request, built a plant 

that just copied the equipment and process used at 

Woolwich. The result was the Wabash River 

Ordinance Works run by E. I. du Pont de Nemours & 

Company. This works had the largest nitric acid plant 

in the world, at that time. The Woolwich process was 

expensive; it needed 11 pounds of strong nitric acid for 

every pound of RDX. 

By early 1941, the NDRC was researching new 

processes. The Woolwich or direct nitration process 

has at least two serious disadvantages: (1) it used large 

amounts of nitric acid and (2) at least one-half of the 


formaldehyde is lost. One mole of 

hexamethylenetetramine could produce at most one 

mole of RDX. At least three laboratories with no 

previous explosive experience were tasked to develop 

better production methods for RDX; they were based 

at Cornell, Michigan and Penn State universities. 

Werner Emmanuel Bachmann, from Michigan, 

successfully developed the "combination process" by 

combining the Canadian process with direct nitration. 

The combination process required large quantities of 

acetic anhydride instead of nitric acid in the old 

British "Woolwich process". Ideally, the combination 

process could produce two moles of RDX from each 

mole of hexamethylenetetramine. 

Vast increases in production of RDX could not 

continue to rely on the use of the beeswax, first used 

in the Woolwich process, to desensitize the RDX. A 

substitute based on petroleum was developed at the 

Bruceton Explosives Research Laboratory (Gilman et 

al., 1953). 2 

Bachmann process 


The NDRC tasked three companies to develop pilot 

plants. They were the Western Cartridge Company, E. 

I. du Pont de Nemours & Company and Tennessee 

Eastman Company, part of Eastman Kodak. The 

Eastman Chemical Company (TEC), Kingsport, 

Tennessee, a leading manufacturer of acetic 

anhydride, Werner Emmanuel Bachmann successfully 

developed a continuous-flow manufacturing process 

for RDX. RDX was crucial to the war effort and the 

current batch-production process could not keep up. 

In February 1942, TEC built the Wexler Bend pilot 

plant and began producing small amounts of RDX 

(Bachmann et al., 1949). 1 This led to the U.S. 

government authorizing TEC to design and build 

Holston Ordnance Works (H.O.W.) in June 1942. By 

April 1943, RDX was being manufactured there. At 

the end of 1944, the Holston plant and the Wabash 

River Ordinance Works (which used the Woolwich 

process) were making 25,000 short tons (23,000 t) 

(50 million pounds) of Composition B per month. The 

U.S. Bachmann process for RDX was found to be 

richer in HMX than the United Kingdom's RDX. This 

later led to a RDX plant using the Bachmann process 

being set up at ROF Bridgwater in 1955, to produce 

both RDX and HMX (Luo et al., 2002). 4 

Military compositions 

The United Kingdom's intention in World War II was 

to use "desensitised" RDX: in the original Woolwich 

process RDX coated with beeswax, but changed to a 

RDX coated with petroleum-based product, based on 

the work carried out at Bruceton. In the event the UK 

was unable to obtain sufficient RDX to meet its needs. 

Some of this shortfall was met by substituting a 

mixture of ammonium nitrate and TNT. Karl Dönitz 

was reputed to have claimed that "an aircraft can no 

more kill a U-boat than a crow can kill a mole". 

However, by May 1942 Wellington bombers began to 

deploy depth charges containing Torpex, a mixture of 

RDX, TNT and aluminium, which had up to 50 per 

cent more destructive power than TNT-filled depth 

charges. Considerable quantities of the RDX–TNT 

mixture were produced at the Holston Ordnance 

Works, with Tennessee Eastman developing an 

automated mixing and cooling process based around 

the use of stainless steel conveyor belts. 

Terrorism 

Ahmed Ressam, the al-Qaeda Millenium Bomber, 

used a small quantity of RDX as one of the 

components in the explosives that he prepared to 

bomb Los Angeles International Airport on New 

Year's Eve 1999/2000; the combined explosives could 

have produced a blast forty times greater than that of 

a devastating car bomb. RDX was main component 

used for the 2006 Mumbai train bombings. It was also 

believed to be the explosive in the 2010 Moscow 

Metro bombings. 

Conclusion 


Trinitro derivative of reduced triazine ring is a small 

molecule but has tremendous explosive property. 

Urotropine is hexamethylene tetramine which is 

obtained by bubbling of air through the mixture of 

formalin and ammonium hydroxide. This urotropine 

is active as urinary tract infection but when it is 

16

treated with nitric acid, it gets nitrated to form RDX 

and methylene dinitrate which has remarkable 

explosive property. The explosive property is approx 

9km/sec! 

References: 

1) Bachmann WE., Sheehan JC. A New Method of 

Preparing the High Explosive RDX, Journal of the 

American Chemical Society 1949; 71(5): 1842–1845. 

2) Gilman H. The Chemistry of Explosives, Organic 

Chemistry an Advanced Treatise, III, Wiley; 

Chapman & Hall, 1953; 985–986. 

3) Hale GC. The Nitration of Hexamethylenetetramine, 

Journal of the American Chemical Society 1925; 

47(11): 2754–2763. 


4) Luo KM, Lin SH, Chang JG, Huang TH. Evaluations 

of kinetic parameters and critical runaway 

conditions in the reaction system of hexamine-nitric 

acid to produce RDX in a non-isothermal batch 

reactor, Journal of Loss Prevention in the Process 

Industries 2002; 15(2): 119–127. 

5) Simmons WH, Forster A, Bowden RC. The 

Manufacture of R.D.X. in Great Britain: Part II – 

Raw Materials and Ancillary Processes, The 

Industrial Chemist 1948; 24: 530–545. 

6) Simmons WH, Forster A, Bowden R. (September 

1948), The Manufacture of R.D.X. in Great Britain: 

Part III – Production of the Explosive, The Industrial 

Chemist 1948; 24: 593–601.

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