The name is absent

46

Axial testing reveals a trend which differs greatly from that of the neat
polymer and the radial testing. There is an obvious peaking of the storage and loss
above a 1% strain amplitude, which is explained by the buckling of the CNTs within
the composite. This peaked strain amplitude is the critical threshold where the
composite transitions from a "bulging” compression to an "S-shaped” global
buckling of the CNTs.

Furthermore, it is curious that in contrast to the radial testing, the
composites have a maximum displacement similar to that of the neat polymer. A
likely explanation for this is that by buckling, the CNTs are preventing the sample
from bulging during compression. The bulging of the sample causes the polymer
chains to become fully-extended at lower strains, hence the lower maximum
displacement. During axial compression, there is much less chain stretching normal
to the direction of deformation, allowing the composite to compress to nearly the
same displacement as the neat polymer.

3.3.2. FrequencySweep

For a particular strain amplitude and temperature, a frequency sweep will
resolve any frequency-dependent behavior for a given sample. With consideration
given to any dependencies due to the dimensions of the sample, particular
interactions which may occur in a sample will be elucidated through this type of
testing. The frequency-dependent testing presented in this thesis is a result of
testing the bottom CNTs and was conducted at room temperature and at a strain
amplitude of 1%, as determined from the observation from the strain sweep testing

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