Radiation synthesis and characterization of xanthan gum hydrogels

Abstract

In this study, xanthan gum (XG) based hydrogels were prepared at a paste like state, in the presence of acetylene gas and CCl4 through γ-irradiation. Sodium polyacrylate/XG semi-interpenetrating networks [P(AAcNa)/XG semi-IPNs] were also prepared and characterized. It was determined that XG could not undergo high gelation when irradiated at a paste like state. Relatively higher gelation was obtained in the presence of CCl4. Irradiations carried out in the presence of acetylene resulted in formation of insoluble structures and viscosity of XG increased almost threefold up to a certain dose. Hydrogel structures with superabsorbent character and highest gelation were obtained with P(AAcNa)/XGsemi-IPNs. Swelling and absorbency under load (AUL)tests showed that P(AAcNa)/XG semi-IPNs have as much fluid absorption capacity as commercially available super absorbent polymers (SAPs). Basic network structural parameters of the P(AAcNa)/XG semi-IPNs were also calculated and characterized by mechanical and rheological tests. It was determined that the addition of XG to the P(AAcNa) structure greatly enhanced the mechanical strength of the hydrogels while fluid absorption capacities were adequately high for a novel XG based superabsorbent hydrogel.