11.5 Filled Polymer Composites 265
11.5
Filled Polymer Composites
11.5.1
General Considerations
Filled polymers have tremendous economic importance; this is because of their
outstanding new or improved properties. The improvement may be in the field
of strength, temperature resistance, or inflammability. The improved property
depends strongly on the type of filler and the way of filling. The latter point is
of special importance, as one may easily lose the specific advantages of nanoparticulate filler when the filler forms aggregates, mimicking large particles. It is
easily understandable that one has to differentiate between more or less spherical
particles as fillers, fibers, or platelets. Figure 11.20 displays stress–strain diagrams of pure and differently filled polymers. The lowest strength is found for
the unfilled polymers, however, at least in the idealized case, the strain at rupture
is largest.
Depending on the shape of the filler, particles, platelets, and on the degree of
agglomeration the strength of such filled polymers is found in a broad range;
however, in general, these are at higher values as compared to unfilled polymer.
As a rule, one may say that the improvement of the properties becomes less pronounced if the particles get larger or agglomerated. Most interesting in this class
of composites are ones filled with silicate platelets. Because of the significantly
reduced inflammability, these materials have, at the moment, the highest economic importance. The highest strength combined with a reasonable ductility is
obtained by filling the polymer with fibers, especially carbon nanotubes.
Figure 11.19 Superplastic deformation of
ZrO 2 (5 wt% Y 2 O 3 ) with grain size in the
range from 45 to 75 nm and densities around
90% TD. The tests were performed under
tension. As these tests were performed at
elevated temperature, unavoidably, grain
growth was observed during the experiments
[15].
0
0.1
0.2
0.3
0.4
0.5
0.6
strain ∆l/l
0
10
20
30
40
50
60
stress
[MPa]
Temperature
1330 K
1400 K
11.5
Filled Polymer Composites
11.5.1
General Considerations
Filled polymers have tremendous economic importance; this is because of their
outstanding new or improved properties. The improvement may be in the field
of strength, temperature resistance, or inflammability. The improved property
depends strongly on the type of filler and the way of filling. The latter point is
of special importance, as one may easily lose the specific advantages of nanoparticulate filler when the filler forms aggregates, mimicking large particles. It is
easily understandable that one has to differentiate between more or less spherical
particles as fillers, fibers, or platelets. Figure 11.20 displays stress–strain diagrams of pure and differently filled polymers. The lowest strength is found for
the unfilled polymers, however, at least in the idealized case, the strain at rupture
is largest.
Depending on the shape of the filler, particles, platelets, and on the degree of
agglomeration the strength of such filled polymers is found in a broad range;
however, in general, these are at higher values as compared to unfilled polymer.
As a rule, one may say that the improvement of the properties becomes less pronounced if the particles get larger or agglomerated. Most interesting in this class
of composites are ones filled with silicate platelets. Because of the significantly
reduced inflammability, these materials have, at the moment, the highest economic importance. The highest strength combined with a reasonable ductility is
obtained by filling the polymer with fibers, especially carbon nanotubes.
Figure 11.19 Superplastic deformation of
ZrO 2 (5 wt% Y 2 O 3 ) with grain size in the
range from 45 to 75 nm and densities around
90% TD. The tests were performed under
tension. As these tests were performed at
elevated temperature, unavoidably, grain
growth was observed during the experiments
[15].
0
0.1
0.2
0.3
0.4
0.5
0.6
strain ∆l/l
0
10
20
30
40
50
60
stress
[MPa]
Temperature
1330 K
1400 K