Los derivados nitrados del 5-amino- 3-nitro- 1,2,4-triazol (ANTA) y del 3-nitro- 1,2,4-triazol- 5-ona (NTO) han sido teóricamente caracterizados con respecto a su desempeño como explosivos y propulsantes. La velocidad y presión de detonación de los derivados, calculadas con el software EXPLO5, estaban al mismo nivel o ligeramente por encima del rendimiento del 1,3,5- trinitroperhidro-1,3,5- triazina (RDX). Los resultados mostraron que composiciones de 1,3,4-trinitro- 1,2,4-triazol- 5-ona y GAP pueden dar impulsos específicos por encima de 2600 m/s en propulsores de cohete.
463
A Study of the Detonation Properties, Propellant Impulses, Impact Sensitivities…
5-nitrimino-3-nitro-1,2,4-triazole, 1,3-dinitro-1,2,4-triazol-5-one and 3,4-dinitro-
1,2,4-triazol-5-one were suggested. When NTO was dissolved in a
mixture of
nitric acid and acetic anhydride the compound decomposed. NTO did not seem
to decompose if chloride-assisted nitration was used and the temperature was
kept below 15
°
C. The FTIR spectrum of a
derivative obtained indicated that
an N−NO
2
bond had been formed in the molecule. However, the derivative was
not stable for more than 24
h at room temperature.
5
Experimental Section
NTO was used as received from Chemring Nobel. Sigma-Aldrich supplied
acetic anhydride and concentrated nitric acid. The FTIR spectra were recorded
on a
Nicolet FTIR (iS10) with diamond ATR. The absorbance bands were
characterized as broad (b), strong (s), medium (m) and weak (w).
5.1
Nitration of NTO in the presence of zinc chloride
Acetic anhydride (1.86
g) was added dropwise to nitric acid (0.69
g) at 0
°
C.
The solution was stirred for 30
min before zinc chloride (0.15
g) was dissolved
in the mixture. After stirring for 30 min, small portions of NTO (0.30
g) were
added. This mixture was stirred for 1
h, heated to 15-18
°
C and stirred overnight.
Finally, it was heated to 40
°
C and stirred for 2
h. During the reaction the
colour of the slurry-like mixture changed from yellow to weak-red and then to
white. The slurry was poured into a
beaker containing ice-cold water and the
precipitate was filtered off and washed with water. The precipitate dissolved
rapidly and decomposed during the washing step. The procedure was repeated
using chloroform instead of water. The precipitate was more stable in this solvent
and was therefore filtered off and dried under vacuum.
IR (ATR):
ῦ
= 3363 (b),
2215 (w), 1542 (s), 1455(s), 1408 (s), 1301(s), 1028 (m), 957 (w), 809 (w) cm
−1
.
Acetic anhydride (1.57
g) was added dropwise to nitric acid (0.57 g) at
0
°
C. After 30
min stirring, zinc chloride (0.27
g) was dissolved in the mixture,
followed by stirring for 30
min. After addition of NTO (0.59
g) in small portions,
the mixture was stirred for 1
h, then heated to 15
°
C and stirred overnight.
Thereafter, the white slurry was poured into cold chloroform and filtered off.
The precipitate was dried under vacuum, washed with acetone, filtered and dried.
FTIR (ATR):
ῦ
= 3207 (b), 1717 (m), 1639 (w), 1546 (s), 1456 (m), 1411 (m),
1369 (m), 1290 (s), 1108 (w), 1022 (m), 977 (m), 861 (w) cm
−1
.
Nitric acid (0.36
g) was cooled to 0
°
C and acetic anhydride (2.06
g) was
then added dropwise. The mixture was stirred for 20
min before zinc chloride
464
T.L. Jensen, J.F. Moxnes, E.F. Kjønstad, E. Unneberg
(0.20
g) was added followed by stirring for 30
min at 0
°
C. Subsequently, small
portions of NTO (0.38
g) were added and the mixture was stirred for 5
h at 0-5
°
C,
poured into cold chloroform (5.0
g), filtered off, washed with chloroform (10.0
g)
and dried under vacuum. The product consisted of small white crystals. FTIR
(ATR):
ῦ
= 3257 (b), 1716 (s), 1634 (w), 1545 (s), 1463 (w), 1412 (w), 1369 (m),
1305 (s), 1282 (s), 1199 (m), 1128 (w), 1003 (m), 978 (m) cm
−1
.
5.2
Nitration of NTO in the presence of ammonium chloride
Acetic anhydride was dripped into nitric acid at 0
°
C. After stirring for 30
min,
ammonium chloride was added. The mixture was stirred for 30
min before the
addition of small portions of NTO, followed by stirring for 1
h. The mixture
was then heated, first to room temperature and stirred for 4
h, then to 35-40
°
C
and stirred for 1
h. The white slurry was poured onto crushed ice, filtered off
and dried. FTIR (ATR):
ῦ
= 3194 (m), 1690 (s), 1539 (m), 1471 (m), 1338 (s),
1279 (m), 1186 (m), 1108 (w), 1005 (m) cm
−1
.
FTIR spectrum of NTO (ATR):
ῦ
= 3194 (m), 1690 (s), 1541 (m), 1471 (m),
1338 (s), 1280 (m), 1187 (m), 1109 (w), 1006 (m) cm
−1
