Biomedical Engineering Reference
In-Depth Information
9.9
Y
1
Ba
2
Cu
3
O
6.97
:RPE = 90:10 SC polymer-ceramic nanocomposite
[25].
morphology. SC polymer-ceramic nanocomposite samples were investi-
gated using electron microscopy (Fig. 9.9). It is seen that in this case, as for
RPE binders, there are fibrils present, which are not typical for RPE. It is
possible that they are the result of the intercalation of RPE macromolecule
fragments into the layered structure of the ceramics. Such a binding
presumably influences the mobility of some RPE macro chains, and it is
logical to assume that crystallization of such macromolecules occurs by
cooperative interaction between them. In the case of SC polymer-ceramic
nanocomposites with i-PP isotactic polypropylene binders, the phenomena
observed above are presented more clearly. As can be seen from the
dependence of heat capacity on temperature (Fig. 9.10; curves 1, 2 and 3), in
this case the heat of fusion splits into two components. One can assume that
this split is connected with the presence of two different types of structure
within the polymer-ceramic nanocomposites. Here, the content of the fibrils
is appreciably higher than that of the RPE binder.
9.5
Interphase phenomena in SC polymer-ceramic
nanocomposites
Figures 9.11 and 9.12 show the temperature dependence of the elastic
modulus (E) and of the loss tangent (tan
) for pure SHMPE and a polymer-
ceramic nanocomposite with 15% filler. Both E and tan
δ
, increase in line
with an increase in the amount of ceramic filler. In both curves, two
transitions are seen. The step in E and the peak in tan
δ
δ
around
100
8
C are
