Microwave-induced Graft Copolymerization of Acrylamide onto Kondagogu Gum: Synthesis, Optimization, and Characterization

Abstract

This study aimed to develop a microwave-assisted graft copolymerization technique for acrylamide onto
Kondagogu gum using potassium persulfate as an initiator, with the objective of improving grafting
efficiency through statistical optimization. Graft copolymerization was carried out under controlled
microwave irradiation conditions using Kondagogu gum, acrylamide monomer, and potassium persulfate
initiator; the reaction mixture was subsequently cooled, precipitated with acetone, dried, and ground. Central
Composite Design (CCD) was employed to evaluate the effects of acrylamide concentration, initiator level,
and irradiation time on grafting performance. The results demonstrated uniform and rapid heating under
microwave irradiation, leading to a significant enhancement in grafting efficiency. CCD analysis revealed
that acrylamide concentration and initiator level were the most influential parameters affecting grafting yield,
with significant interaction effects (AB and BC). Under optimized conditions (acrylamide 24.99 g, initiator
0.154 g, irradiation time 88.9 s), predicted grafting yield and efficiency values of 94.10% and 82.84%,
respectively, were achieved with a desirability value of 1.000. Successful graft copolymer formation was
confirmed by FTIR spectroscopy through the appearance and shifting of characteristic amide and hydroxyl
bands. Swelling studies indicated that the grafted gum exhibited enhanced water uptake compared to the
native polymer, reflecting improved hydrophilicity. Overall, microwave-assisted grafting proved to be a rapid,

efficient, and environmentally friendly method for modifying natural gums, and the optimized acrylamide-
grafted Kondagogu gum demonstrated enhanced physicochemical and swelling properties, making it suitable

for pharmaceutical and biomedical applications.