Chemistry Reference
In-Depth Information
Fig. 5.16
The grafting mechanism of AG with aniline initiated by MW and APS [
26
]
Recently, gamma irradiation-initiated graft polymerization was developed as a
preferred method for commercial synthesis and exhibits a great potential to synthe-
size the graft copolymers by virtue of its higher efficiency, low cost, and convenient
to modify polymer [
171
,
172
]. The utilization of gamma irradiation for the synthe-
sis of gum-g-copolymers has been intensively concerned. For example, Lokhande
et al. [
173
] and Biswal et al. [
174
] prepared guar gum-g-copolymer by using
γ
-radiation as the initiation approach. It was found that ideal graft efficiency was
obtained, and the graft efficiency is dependent on the dose of radiation. The increase
of radiation dose can enhance the graft ratio and decrease the content of
homopolymers, but the viscosity or molecular weight was decreased due to the
depolymerization effect of radiation to gum. Besides, the graft copolymer of other
gums such as XG [
175
] and KG [
54
] was reported. However, the problems
associated with radiation initiation involve lack of distinction between the different
bonds of the backbone polymer because there is always a strong probability of
radiation damage (radiolysis) to the gum backbone, and undesirable breakage of
bonds may occur under the action of strong radiation [
176
]. In addition, this method
