Biomedical Engineering Reference
In-Depth Information
9.8
Heat capacity vs. temperature for SC polymer-ceramic samples
obtained at different initial temperatures (
T
0
) and with different ratios of
ceramic:RPE.
C) = 130 (curves 1, 4, 5), 140 (curve 2), 160 (curve 3).
Y
1
Ba
2
Cu
3
O
6.97
:RPE = 90:10 (curves 1-3), 97:3 (curve 4), 99:1 (cruve 5) [25].
T
0
(
8
Table 9.6
Melting temperatures (
T
m
) and enthalpies (
ΔH
m
) of nanocomposites
depending on content
Y
1
Ba
2
Cu
3
O
6.97
:
i-PP (mass%)
ΔН
m
calc. for 1 g
sample (J g
1
)
ΔН
m
calc. for 1 g
RPE (J g
1
)
Crystallinity
(%)
Т
m
(
8
C)
90:10
107
8.4
84
28.6
97:3
107
2.9
97
33
99:1
105
1.3
133
45
9.4.2 Thermo-physical properties and morphological
characteristics of SC polymer-ceramic
nanocomposites
The thermal capacity dependence of polymer-ceramic nanocomposites with
ramified polyethylene (RPE) is shown in Fig. 9.8. From curves 1-3 it can be
seen that the initial formation temperature of polymer-ceramic SC samples
has practically no influence on the heat of fusion. As expected, the heat of
fusion changes dramatically depending on the samples' content. Melting
points and enthalpies for SC polymer-ceramic nanocomposites with RPE
binders are presented in Table 9.6, using values
calculated from
experimentally obtained data.
The strong increase of
H
m
value (calculated for RPE) could be the result
of two reasons. One is that the increase in quantity of SC ceramics leads to
an increase of crystallinity. The second and more possible cause is that RPE
macromolecule fragments intercalate [25, 26]
Δ
into the interstitial
layers
between the ceramic grains,
leading to changes in the crystalline RPE
