Environmental Engineering Reference
In-Depth Information
Table 6.4 Testing results of falling down from 50 m height
Experiment
1 23456789 0Other phenomena
1,3-diazidopropane
(20 %)
××××××××××
Temperature increased up
20
°
C
1,3-diazidopropane (0)
××××××××××
Temperature increased up
20
°
C
6.2.5.3 Preparation of 1,3-Diazidopropane [
1
,
3
]
(1) Synthesis mechanism
There are a lot of preparation methods for aliphatic diazides. The most common
and convenient method is the displacement reaction of dihalogenerated hydrocar-
bons and sodium azide. The reaction is displayer in below general expression.
X(CH
2
)
n
X + 2NaN
3
!
N
3
(CH
2
)
n
N
3
+ 2NaX n
¼
2
3
4
5
6
;
;
;
;
...
The alphatic dihalogenerated hydrocarbons of linear chains are primary halo-
generated hydrocarbons. N
3
−
is a kind of strong nucleophile. So, it is predictable
that the above reaction has SN2 reaction mechanism.
(2) Preparation
Certain amount of sodium azide is dissolved in water, and then 95 % ethanol
with bromoalkane is added. Later, the mixture is heated to 70
C and reluxs
until the colorless oily liquid is produced. After reaction, the product is washed
using water, and extracted using diethyl ether. The extraction liquid is dried by
MgSO
4
. Diethyl ether is evaporated at normal pressure, and the colorless oily liquid
product 1,3-diazidopropane is evaporated under reduced pressure and collected.
The yield is 93.6 %. The processes of 1,3-diazidopropane preparations are in
Fig.
6.1
.
To study the relationship of 1,3-diazidopropane yield and reaction time, and
temperature, experiments are designed in Tables.
6.5
and
6.6
.
The analysis of 1,3-diazidopropane is in Table
6.7
. Figures
6.2
and
6.3
shows
the structures of 1,3-diazidopropane.
1,3-diazidopropane is a colorless and transparent liquid with molecular weight
126.12. Its density is 1.1042 g/cm
3
. The boiling point is 150
90
°
-
°
-
151
C at ambient
pressure, and 50
C under 6 mmHg pressure. Liquid water content is 12 ppm.
1,3-diazidopropane is not volatile at room temperature. After 12 h of moisture
absorption, the weight increasing is
60
°
-
52.69 %. The saturated vapor pressures of
1,3-diazidopropane under different temperatures are in Table
6.8
.
Thermal decomposition study of 1,3-diazidopropane (Fig.
6.4
)
The peak temperature of 1,3-diazidopropane thermal decomposition temperature
is at 179.32
−
°
C.
