Synthesis and Characterization of Graft Copolymer Rice Straw Cellulose-Acrylamide Hydrogels Using Gamma Irradiation

Rice straw cellulose available as waste biomass was graft copolymerized with
acrylamide monomer by simultaneous gamma irradiation as initiator. The effects of
bleaching of cellulose and irradiation dose were evaluated. Evidence of grafting is
obtained from comparison of Fourier Transfer Infrared (FTIR) of the cellulose and
grafted cellulose. X-ray diffraction analysis shows that crystallinity was reduced
through graft copolymerization. Kinetic investigations of the graft copolymerization
were also carried out, and the rate constant parameter (kp/kt
0.5) has been found to be
4.9922 l0.5. mol-0.5.s-0.5. The results show that for the same dose, grafting efficiency
is higher with the bleached cellulose form than with the unbleached form. The
grafting efficiency and the gel fraction increases with increasing total irradiation
doses. At higher radiation doses crosslink density starts to increase considerably
while swelling degree decreases with the increasing crosslink density.