Objective: The objective of the work was to synthesize polyacrylamide
(PAAm) grafted locust bean gum (LBG) via conventional method using ceric ammonium
nitrate (CAN) as free radical initiator to improve flocculation efficiency.
Method: The effects of concentration of CAN, acrylamide (AAm), LBG, reaction
time, and temperature on grafting were studied to determine the grafting percentage
and grafting efficiency. The synthesized graft copolymers have been characterized
by Fourier transform infrared (FT-IR) spectroscopy, differential scanning
calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy
(SEM). The swelling of graft copolymer was measured in different solutions with
pH values ranging from 1 to 12. Viscosity of the polymer solutions were carried
out with an Oswald viscometer. Flocculation efficacy of the graft copolymer was studied in kaolin
suspension. The acute oral toxicity study of graft polymer was evaluated as per OECD guide line.
Results: The graft copolymer shows swelling-deswelling behavior in buffer solutions with pH 2.0 and
9.0. The intrinsic viscosity of LBG improved significantly on grafting of polyacrylamide chains.
Grafted copolymer gives better performance by showing lower turbidity than LBG. No mortality of
the animal was observed during 14 days after treatment with graft copolymer.
Conclusion: Among the grafted LBG, the graft copolymers showing higher intrinsic viscosity were
the most efficient flocculent.