Chemistry Reference
In-Depth Information
pulp were found to be 2,500-2,700 g/g and 40-60 g/g, respectively [
98
]. The
grafting of water-soluble vinyl monomers onto amine-treated cotton fiber gave a
graft copolymer with enhanced moisture sorption ability that can be used in fabrics,
such as underwear and athletic wear [
80
]. Cellulose graft copolymers synthesized in
DMSO-PF solvent system has been used as permselective membranes [
143
,
144
].
Cellulose-thiocarbamate-g-PAN had high antimicrobial activity. Matahwa et al.
[
84
] reported that
N
-isopropyl acrylamide and methyl acrylate-grafted cellulose as
template in the crystallization of CaCO
3
has better nucleating property than cellu-
lose. In addition, the cellulose graft copolymers obtained by grafting of vinyl
monomers with functional groups such as acrylamide [
21
], acrylic acid
[
58
,
145
-
147
], acrylonitrile, and 2-acrylamidomethylpropane sulfonic acid [
145
]
have been used in the adsorption of hazardous contaminants such as heavy metal
ions or dyes [
66
] from aqueous solutions [
148
,
149
]. The product of poly(4-vinyl
pyridine)-grafted cellulose with sodium borohydride has been used as reducing
agents for various carbonyl compound such as benzaldehyde, cyclohexanone,
crotonaldehyde, acetone, and furfural [
96
]. Wang et al. [
31
] reported that pH-
responsive poly(2-diethylamino) ethyl methacrylate grafted-ethyl cellulose
(EC-g-PDEAEMA) synthesized by ATRP can be used in the pH-responsive release
of rifampicin (RIF). In addition, another graft product obtained by ATRP, which is
graft copolymer of ethyl cellulose with azobenzene-containing polymethacrylates
[
113
], was reported to be used in the some applications such as sensors and optical
materials. In recent years, cellulose graft copolymers with thermosensitive graft
chains such as poly(
N
-isopropylacrylamide or poly(
N
,
N
-diethylacrylamide) have
been used in the removal of heavy metal ions from aqueous solutions by tempera-
ture swing adsorption (TSA) which is different from the removal of metal ions by
complexation or ion exchange [
29
,
30
,
150
-
154
].
2.6 Conclusion
Cellulose graft copolymers can be prepared in homogeneous or in heterogeneous
medium. Grafting can be confirmed by gravimetry, volumetric method (a simple
acid-base titration), or spectroscopic methods such as FTIR, NMR, and SEM.
Cellulose gains hydrophilic or hydrophobic character depending on the monomer
grafted. Therefore, cellulose graft copolymers have many applications. Among
them, heavy metal and dye removal from aqueous solutions are the most promi-
nent ones. In the grafting reactions performed in homogeneous medium, the
grafting can be controlled better, and higher number of grafts per cellulose
chain is obtained. By these methods such as RAFT and ATRP methods, tailor-
made copolymers such as comb- or brush-type cellulose graft copolymers can be
synthesized. The applications of these special polymers will be studied more in
the near future.
