Chemistry Reference
In-Depth Information
Table 4.2
Total heats of linear pyrolysis for hybrid propellant polymers and fuels
Material
T
0
,
◦
C
Q
Σ
,Jg
−
1
Material of
the block
PMMA (linear)
Duralumin
485
1583
±
40
PMMA (linear)
Copper
665
1666
±
40
PMMA + 2wt %
triethyleneglycoldimethacrylate
Copper
665
1480
±
20
PMMA + 10 wt %
triethyleneglycoldimethacrylate
Copper
665
1540
±
20
Polyethylene
Copper
665
2354
±
40
Polystyrene
Copper
665
1875
±
40
Polyethyleneimine
Duralumin
485
1646
±
40
Rubber resin-SKDN
Duralumin
485
625
±
20
Rubber resin-PDI-1
Duralumin
485
875
±
20
Diene polymer
Duralumin
485
1041
±
40
30 wt% rubber
resin-SKDN + 70 wt%
transformer oil
Duralumin
485
980
±
20
40 wt% rubber
resin-SKDN + 60 wt%
transformer oil
Duralumin
485
625
±
20
60 wt% rubber
resin-SKDN + 40 wt%
transformer oil
Duralumin
485
646
±
20
±
Transformer oil
Duralumin
350
1333
40
Polyurethane-DT
Duralumin
485
1541
±
40
Chloropolyurethane
Duralumin
485
875
±
40
20 wt% organic
azide-APU + 80 wt%
polyurethane-DT
Duralumin
485
790
±
20
64 wt% organic
azide-APU + 16 wt% rubber
resin-PDI-1 + 20 wt%
polyethylene
Duralumin
485
416
±
20
20 wt% organic
azide-APU + 80 wt% rubber
resin-SKDN
Duralumin
485
333
±
20
rate. In the experiments, cylindrical samples (100 mm long, initial hole diameter of
13 mm) were burned in flowing oxygen at an O
2
pressure of 1.5 MPa and a flux
density of 60 g cm
−
2
s
−
1
.
A plot of the experimental weight-average burning rate (
m
=
u
γ
s
, where
u
is the
average burning rate for the polymer fuel and
γ
s
is the density of the polymer fuel)
against the corresponding total heat of linear pyrolysis is shown in Fig. 4.4.
The complicated mechanism of blowing-assisted burning in the interface layer
that is characteristic of a hybrid rocket engine is not considered in detail here. How-
ever, one can draw a conclusion about the decrease in the burning rate of a polymer
fuel with increasing
Q
∑
. The correctness of this conclusion is confirmed by the fact
