urbaf2

404 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

which reacts with sodium sulphite to form a sulpho derivative:

The solubility of the trinitro derivatives of o- and p- xylene in various solvents

is higher than that of trinitro-m-xylene. Here are the comparative data on the solu-

bilities in 100 ml of 95% alcohol at 8°C (after Kravchinskii [3]):

2,4,6-trinitro-m-xylene 0.024 g

3,4,5-trinitro-o-xylene 0.874 g

3,4,6-trinitro-o-xylene 1.159 g

2,3,5-trinitro-p-xylene 0.325 g

Xylene

Manufacture of trinitroxylene (TNX).......................

The success of the nitration process, from the point of view of the quality and

yield of the product as well as of safety, depends to a considerable extent on the

quality of the xylene used. For nitration, both xylene from coal pyrolysis and from

petroleum is used. In both cases m- xylene is the main component of the crude sub-

stance.

The average composition of xylene from coal is:

o- xylene 10% (b. p. 141°C, sp. gr. 0.863)

m- xylene 66% (b. p. 139°C, sp. gr. 0.862)

p- xylene 20% (b. p. 136°C, sp. gr. 0.861)

ethylbenzene 4% (IL p. 136°C, sp. gr. 0.876)

Xylene obtained by cracking heavy petroleum hydrocarbons has approximately:

20-47% of o- and p- xylene, 30-45% of m- xylene, 12-25% of ethylbenzene and

8-10% aliphatic hydrocarbons.
The composition of the xylene obtained by distillation of Borneo petroleum
is much the same as that of the xylene from coal.
Due to a relatively high content of the m- isomer xylene derived from coal or
xylene from Borneo oil is the most convenient starting material for the preparation

of nitration grade xylene.