dependence of storage modulus for dispersions containing 1 wt% SWCNT (modified and unmodified) in epoxy precursors. Solid-like behavior is observed for both
the dispersions in the low frequency region and importantly, much higher storage
modulus was observed for acid functionalized SWCNT in the similar filler loading
and frequency as compared to nonfunctionalized SWCNT composite. This phenomenon is explained on the basis of better dispersion of functionalized SWCNT in
epoxy precursors due to better interaction with the matrix [111]. The storage
modulus increase with filler concentration and a power law relation is used to
determine the threshold of rheological percolation [109, 112] G
/ ~ (wt% À wt
Fig. 10 (a) Storage modulus (G
/
) as a function of frequency at T ¼ 120
C for different CNT
contents in rubber matrix. (b) Modulus of complex shear viscosity [η*] as a function of frequency
for different CNT contents in rubber [107]
Fig. 11 Frequency response of the storage modulus for dispersions containing 1 wt% SWCNT
unmodified or SWCNT-COOH in epoxy precursors [111]
Nonlinear Viscoelasticity of One Dimensional Filler Reinforced Elastomer. . .
31