Environmental Engineering Reference
In-Depth Information
4.2 Properties of Liquid Nitro Explosives
Nitroalkane, nitrobenzene, nitrotoluene and nitro alcohol are common and the most-
used liquid nitro explosives. Physical and chemical properties, and explosive per-
formance of these liquid explosives are signi
cantly different with different com-
position or structures.
4.2.1 Physical Properties of Liquid Nitro Compounds
Lower homologs of nitroalkanes are usually colorless and transparent liquid with
density that is slightly larger than that of water, and fragrance. With the growth of
carbon chain, boiling point is gradually increased, and the density is decreased. The
boiling point of nitroalkane is much higher than that of its isomer-nitrite ester; the
solubility of mononitroalkane in water is decreased with the growth of carbon
chain, it can be dissolved easily in most organic solvents, and it is not soluble in
aliphatic and alicyclic hydrocarbons; Lower aromatic nitro compounds are dif
cult
to dissolve in water, and solubility of nitro alcohol in water is greater than that of
nitroalkane and lower liquid aromatic nitro compound. Lower nitroalkane itself is a
good solvent to dissolve cellulose acetate, cellulose propionate, butyrate, nitrocel-
lulose, vinyl resins, dyes, oils, fats, waxes and others; Because nitro alcohol, cyclic
nitroalkane and nitrobenzene can dissolve most organics, nitroalkanes and lower
cyclic nitro compounds are not only widely used in the liquid explosive industry,
but also have broad application prospects in chemical industry.
Heat of combustion (
−D
H) and oxygen balance of nitroalkane have an linear
relationship [
2
], obeying the enthalpy equation with an error within 1.8 %.
2
z
M
2x
þ
D
H
c
¼
176
:
9
þ
7
;
499 J/g
wherein x, y and z are the number of oxygen atoms, hydrogens and carbons of the
molecule, respectively; M is relative molecular mass.
Nitroalkane has two characteristic UV absorption peaks, including relatively
strong absorption peaks at 210 and 280 nm (K
max
=23
26). Regardless of the
-
locations of nitro groups, the extinction coef
cient of dinitro compound is almost
doubled, thus, the number of nitro groups can be determined from the extinction
coef
cient of the absorption peak; when nitro group and amino group, two or more
hydroxyl groups form intramolecular hydrogen bonds, red shift effect will occur
compared to that of the original nitroalkane, with peak shift of 8
20 mm [
3
,
4
].
Nitro in nitroalkane has two infrared absorption peaks, and Fig.
4.1
shows
the infrared spectrum of typical liquid nitro compound measured in our group.
-
