The name is absent

44

In Figure 3.6 the strain sweep data for the bottom composite is presented for
a .5 Hz, room temperature test. When tested radially, aside from the obvious
observation that the storage and loss of the composites is approximately 4- to 5-fold
greater than the neat polymer, interestingly the composites do not displace nearly
as much as the neat PDMS before reaching the final stage Ofelastomer deformation.
The mechanism of elastomers' high elasticity lies in the ability for the polymer
chains to elongate under stress. At the point where its polymer backbones are fully
stretched, an elastomer will resist further deformation and its properties will spike
rapidly. There are two likely explanations for the decreased strain limit for the
composites: 1) at this strain the polymer may largely have been pushed out from in-
between the CNTs, which would promote much more CNT-CNT physical interaction,
and/or 2) the entanglement of the chains around the CNTs may reduce their
mobility and result in the full elongation of those chains at lower strains. The first
mechanism is fairly self-explanatory, but the second can be rationalized through the
mechanism by which the polymer infiltrates the forest of CNTs. The polymer chains
work their way between the A-CNTs from all directions and at differing rates. As
such, the entanglement of the polymer chains around the CNTs is most likely very
high. As the composites are stressed and the chains begin to elongate to
accommodate that strain, entanglement around the CNTs will inhibit displacement
to strains which are normally achievable for the neat polymer.

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