Superabsorbent polymer based on guar gum-graft-acrylamide: synthesis and characterization

Superabsorbent polymers of guar gum -graft-acrylamide were synthesized using KPS as a free radical initiator in the presence of Tetra (ethylene glycol) diacrylate as a cross linker using solution graft copolymerization technique. The structures of the grafted copolymers GG-g-PAAm were characterized by FT-IR spectroscopy thermo gravimetric and SEM analysis. The effect of reaction parameters such as concentration of guar gum, acrylamide, KPS, crosslinker (TEGDA), and NaOH (neutralizing agent) were optimized to achieve a superabsorbent polymers with high swelling capacity of 80 g/g (deionisied water) and 22 g/g (0.8 wt% sodium chloride solution). The swelling kinetics of the synthesized superabsorbent were analyzed by applying the Fickian diffusion model and the Schott's pseudo second order kinetics model, illuminating that chain leisure behavior during absorption had a great effect on whole absorbency.