B. Ma et al. / Carbohydrate Polymers 88 (2012) 347–351
351
Table 2
Mechanical properties of the regenerated composite fiber and cellulose fiber.
Sample ID
Fineness (dtex)
Ratio of dry stretch (%)
Dry intensity (cN/dtex)
Initial Young
modulus (cN/dtex)
Composite fiber prepared by dry–wet spinning process
Composite fiber prepared by wet spinning process
Cellulose fiber prepared by dry–wet spinning process
8.15
8.48
8.30
4.58 ± 0.38
13.79 ± 1.52
7.23 ± 0.84
4.63 ± 0.31
1.74 ± 0.13
2.46 ± 0.18
233.12 ± 16.31
70.75 ± 7.34
108.43 ± 10.63
from 108.43 to 233.12 cN/dtex, however, the elongation at break
decreased by 36% from 7.23% to 4.58%. The enhanced mechanical
properties are due to the uniform dispersion of chitosan and the
hydrogen bond between chitosan and cellulose. It is well known
that chitosan have amino group and hydroxyl groups and cellulose
have hydroxyl groups, it is easy for them to form some interaction,
i.e. hydrogen bond. The structure of chitosan is similar to that of cel-
lulose, which ensures the excellent compatibility between them.
The excellent compatibility and strong interaction between chi-
tosan and cellulose macromolecules greatly enhance the interfacial
adhesion and thus significantly improve the mechanical properties
of the composite fiber.
while a sufficiently strong stretch is also necessary in order to
obtain fibers with excellent mechanical properties. As compared to
the reported solvents in most references, there is no doubt that the
Gly·HCl/[Bmim]Cl binary system is simple, convenient and effective
for the preparation of chitosan/cellulose composite fiber.
Acknowledgments
This work was supported by grants from the Natural Science
Foundation of China No. 51103019 and No. 21174027, Shanghai
Pujiang Program (08PJ1400900) and the Programme of Introducing
Talents of Discipline to Universities (No. 111-2-04).
On the other hand, the tensile strength of the composite fibers
prepared by wet spinning is only 1.74 cN/dtex, which is far less
than that of the composite fibers prepared by dry–wet spinning. It
is due to the low stretch during wet spinning process, which leads
to the chitosan macromolecules chains exist in curling state. In this
case, the introduction of chitosan will be as a defect. Therefore,
the introduced chitosan reinforce the regenerated cellulose matrix,
but the strong stretch is necessary in order to obtain fibers with
excellent mechanical properties.
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