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best i tted the experimental values. Both models do not consider the formation of a
CNC percolating network via whisker-whisker interactions, so particles were assumed
not to interact with each other. According to the authors, in the case of the bionano-
composites based on the lower HS content matrix, the reinforcing ef ect comes from
the nucleation ef ect, but in the case of the bionanocomposites based on the higher
HS content matrix, the reinforcement comes just from the addition of CNCs. Another
important conclusion from this work, obtained by analyzing together the results from
thermal, morphological, and mechanical characterizations, was that CNCs tend to
interact with segments that do not form ordered domains.
Floros
et al.
[63] dispersed nanocellulose in dif erent concentrations (0.1, 0.5, 1.0,
1.5, 2.0 and 2.5% by weight) into a completely biobased thermoplastic polyurethane
(TPU) derived entirely from oleic acid, using 1,18-octadec-9-endiol (ODEDO),
1,7-heptamethylene diisocyanate (HPMDI), and 1,9-nonanediol (NDO), each synthe-
sized entirely from vegetable oil [64-66]. In this case, the cellulose was extracted from
250
Halpin-Kardos
Pan
Percolation
Experimental data
200
150
100
50
0.00
0.02
0.04
ν
R
0.06
0.08
(
a
)
250
Halpin-Kardos
Pan
Percolation
Experimental data
200
150
100
50
0.00
0.02
0.04
ν
R
0.06
0.08
(
b
)
Figure 3.9
Storage modulus (measured at a higher T than the melting of the SS) of bionanocomposites
based on a biobased PU with (a) 17% HS and (b) 46% HS as a function of the volume fraction of cellulose
nanocrystals. Reproduced with permission from [12] .
