Chemistry Reference
In-Depth Information
Figure 8.16 Dynamic mechanical analysis results. (a) Storage modulus and
(b) damping parameter for the polymer matrices obtained from
DCPD-UPR-TO polymers with different TO contents.
Storage modulus (E
0
), glass-transition temperature (T
g
), cross-link density
(n
e
), and effective molar mass between cross-links (M
c
) and 10 and 50%
weight-loss temperatures (T
10
and T
50
) of the neat DCPD-UPR and DCPD-
UPR-TO polymer matrices.
Table 8.3
E
0
at
25 1C/GPa
M
c
/
g mol
1
T
g
/1C n
e
/10
3
mol m
3
Sample
T
10
/1C T
50
/1C
DCPD-UPR
1.53
79.3
2.81
391
294.5
382.0
DCPD-UPR-TO5
1.26
61.8
2.73
403
294.5
384.5
DCPD-UPR-TO10
1.24
65.6
2.59
424
302.0
389.5
DCPD-UPR-TO15
0.802
60.7
2.40
458
294.5
387.0
DCPD-UPR-TO20
0.490
53.1
2.29
480
292.0
389.5
The storage moduli of all the DCPD-UPR-TO bio-plastics at 25 1C were lower
than that of the neat DCPD-UPR, which means the dynamic mechanical
properties of the DCPD-UPR-TO matrices were decreased by the addition of
TO. Based on eqn (4), the n
e
and M
c
values were determined, as shown in
Table 8.3. The E
0
values used for the calculations were taken at approxi-
mately 50 1C above the T
g
. The density of the DCPD-UPR-TO resins
ranged from 1.098 to 1.10 g cm
3
. The n
e
values were in the range of 2290-
2810 mol m
3
, which corresponds to M
c
values of 391-480 g mol
1
. It was
found that E
0
at 25 1C and n
e
decreased as the TO content increased. This is
mainly because the intermolecular Diels-Alder reaction between polyester
and TO reduces the number of reactive C
ΒΌ
C bonds on the polyester chains.
T
g
is determined from the peak of tan d. It can be seen from Figure 8.16(b)
and Table 8.3 that the T
g
value of the DCPD-UPR-TO bio-plastic was reduced
