Chemistry Reference
In-Depth Information
Fig. 3.11
Determination of
U
(
T
S
)fromdataon
U
(
T
0
)
for linear PMMA (
circles
)
and for samples of
crosslinked PMMA with 2%
(
multiplication symbols
)and
10% (
crosses
) crosslinking
agent
kg
ms
Fig. 3.12
Experimental
relations for
U
(
T
0
)and
U
(
T
S
), calculated using the
approximate method for the
linear pyrolysis of linear and
crosslinked PMMA
U
, mm/
s
amount of the
cross-links, %
0. 8
1. 0
1. 2
Data on the linear pyrolysis of linear and crosslinked PMMA are presented in
the Arrhenius anamorphism in Fig. 3.12 (the
T
S
values are determined from the data
presented in Figs. 3.8 and 3.11 using the approximate method described above). The
U
(
T
0
) dependencies are also shown in Fig. 3.12 for comparison.
3.2.3 Linear Pyrolysis of PMMA at Elevated Pressures
In the experiments with flat samples of PMMA (3
30 mm) at
W
= 4N,
P
∞
= 2
and 5 MPa (N
2
),
T
0
= 450-700
◦
C and
U
= 0
.
1-0
.
6mms
−
1
, installation LP-2 was
used. In order to be able to compare the results, similar experiments were performed
at a normal pressure.
At
P
∞
≤
×
18
×
2-3 MPa and
U
= 0
.
1-0
.
6mms
−
1
, steady linear pyrolysis was observed.
The steady state of the process under the indicated conditions was also confirmed
by special experiments performed at
P
∞
= 1, 3, 4 and 6 MPa.
