urbaf2

Nitro derivatives of ethylbenzene.........................

"close to boiling point”. Later Beilstein and Kuhlberg [21], in a paper published

in 1870, which describes the most extensive work on the nitration of aromatic

hydrocarbons carried out in the last century, gave details of the nitration of o-,

m-, and p- toluencs to trinitro derivatives. Besides α− trinitrotoluene they also iso-

lated the γ− isomer.

The β− and γ− isomers were obtained by Hepp [35] in 1882. The constitution

of the α -isomer was determined by Claus and Becker [36] in 1883, and that of the

β− and γ by Will [37] in 1914 (see also pp. 311 and 336, 337).

PHYSICAL PROPERTIES

α− Trinitrotoluene crystallizes in the form of small columns or needles.

According to Artini [38], α− trinitrotoluene forms monoclinic crystals, of the

prismatic class, with the axial ratio a:b:c = 1.64047:1:0.61936.

Melting point and purity. The melting point of α− trinitrotoluene has been

determined by several workers as 80.6°C, 80.65°C, 80.8-80.85°C, 80.66°C. The

value of 80.65°C is generally accepted, and usually determined as setting point.

Three grades of commercial TNT are usually prepared, the main difference

between them consisting in their purity and hence in the melting point. The stand-

ards for TNT, accepted in several countries, differ somewhat.

Polish standards of 1930 cover the requirements for the following grades

of TNT:

I. m.p. 80.3°C

II. m.p. 80.0°C

III. m.p. 76.0°C

U.S.S.R. standards (Gorst [2]) specify the following grades of TNT:

I. military TNT m.p. 80.2°C

II. TNT for the manufacture of ammonites:

(a) sulphited (for permissible explosives) m.p. 80.0°C

(b) washed only m.p. 77.5°C

III. waste TNT m.p. 75.0°C

In Great Britain, during World War I the following minimum melting points

of TNT were specified:

I. m.p. 80.0°C

II. m.p. 79.5°C

III. m.p. 76.0°C

In the U. S. A. two grades of TNT have been introduced on the market:

I. m.p. 80.2°C

IL m.p. 76.0°C

According to Gorst [2], the U. S. S. R. requirements to crystallized TNT are

as follows.

(1) Light yellow crystalline powder without any visible foreign inclusion. Should pass

through the 3 mm size sieve.

(2) Setting temperature not below 80.2°C