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O
OH
OCH
2
CH-CH
2
OH
CHO
O
O
O
O
CICH
2
CH-CH
2
OH
OH
OH
CH
3
OH
NH
2
N-CH
N-CH
NaOH
Chitosan
HCI
OH
O
OCH
2
CH-CH
2
O-CD
CICH
2
CH-CH
2
O
CD
O
NaOH
OH
OH
NH
2
NH
2
CD-chitosan
Figure 2.29
Reaction scheme for the synthesis of β-CD-graft-chitosan via epoxy-activated chitosan. (From Zhang, X.,
Wang, Y., and Yi, Y. 2004.
J Appl Polym Sci
94: 860-864. With permission.)
by esterification of β-CD with itaconic acid in a semidry process and then the pendant
double bonds of β-CD itaconate were utilized in graft copolymerization onto chitosan
(Figure 2.30). The resultant product was then subjected to cross-linking using different
concentrations of glutaraldehyde. This cross-linked chitosan derivative was evaluated as a
new adsorbent for three classes of dyes (acid, basic, and hydrolyzed reactive), because it
has three different active groups such as carboxyl groups, amino groups, and CD-ring
O
H
2
C-COOH
H
2
C-COO-CD
H
2
C-C
Catalyst and/or heat
CD-OH
O
C-COOH
C-COOH
C-C
Catalyst and/or heat
-H
2
O
O
CH
2
Itaconic acid
CH
2
CH
2
CD-itaconate
Itaconic anhydride
CAN
Chitosan
40-50°C
H
2
C-COO-CD
HC-COOH
CH
2
O
O
CD itaconate-graft-chitosan
OH
NH
2
Figure 2.30
Reaction scheme for the synthesis of β-CD itaconate-graft-chitosan using CAN. (From Gaffar, M. A., Rafie, S.
M. E., and Tahlawy, K. F. E. 2004.
Carbohydr Polym
56: 387-396. With permission.)
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