4. Conclusions
NCCs isolated from bleached aspen kraft pulp by acid hydrolysis
are parallelepiped rod-like structures with cross-sectional dimensions
in the nanometer range. NCC with crystallinity more than 80%,
and yield between 25% and 30% could be extracted using 64 wt%
sulfuric acid.
NCC can be used for improving properties of deinked pulp.
The retention of fillers and fines in the deinked pulp could be
improved by addition of NCC. The breaking length and tear index
were improved. However, the drainage rate was negatively affected
to some extent.
NCC could be used in the microparticle retention system as
the organic anionic particle, due to its nano range diameter and
surface charge density. The retention and strength properties
could be further improved when NCC was used together with
CPAM/CS.
Acknowledgments
The authors would like to thank the funding of National
Natural Science Foundation of China (Grant Nos. 20706036 and
30972327), Shandong Provincial Outstanding Youth Scholar Foundation
for Scientific Research (Grant Nos. 2009BSB01053 and
BS2010CL041) and the Program for the Scholar of Yellow River
Mouth (DYRC20120105).