Biomedical Engineering Reference
In-Depth Information
OH
O
NH
2
+
HO
O
O
H
R
O
O
HO
NH
OH
O
CH
3
0.06
0.94
R =
1. 1% (v/v) AcOH
2. NaCNBH
3
N
N
CH
3
H
3
C
N
CH
3
H
3
C
R
OH
OH
NH
HO
O
O
O
O
O
O
HO
HO
NH
2
NH
OH
O
CH
3
x
0.94-x
0.06
Nal
CH
3
l
NMP, NaOH, 60°C
15% (w/v) NaCl
-
Cl
R
′
CH
3
H
3
C
OH
OCH
3
OH
H
3
C
+
NH
N
HO
HO
O
O
O
O
O
O
O
O
O
O
HO
HO
HO
NH
N
NH
OCH
3
OH
H
3
C
CH
3
O
H
3
C
CH
3
x
w
y
z
0.06
R
′
=
+
-
N
Cl
-
N
+
CH
3
Cl
CH
3
H
3
C
Cl
-
+
CH
3
N
CH
3
H
3
C
CH
3
Figure 2.11
Synthesis of the quaternary ammonium chitosan containing aromatic moieties.
to fairly different reactivities of the two hydroxyl groups and the amino group on the repeat-
ing unit of chitosan, acylation can be controlled at the expected sites, that is, on amino [61-63],
hydroxyls [64], or both groups [65-68]. The introduction of hydrophobic branches generally
endows the polymers with new physicochemical properties such as the formation of poly-
meric assemblies, including gels [69], polymeric vesicles [70], Langmuir-Blodgett films
[71,72], liquid crystals [73,74], membranes [75], and fibers [76,77]. Hydrophobic associating
water-soluble polymers have emerged as a new class of industrially important macromole-
cules. Some of these are intended to mimic the endotoxins. The introduction of hydrophobic
branches also endows the polymers with a better soluble range than chitosan itself.
Search WWH ::
Custom Search