Abstract
Genipin, a naturally occurring crosslinker, was employed to modify agarose in aqueous medium at pH ∼ 7 at ambient conditions. The physical and rheological properties were studied. The genipin‐fixed agarose hydrogel (0.8 wt % genipin with respect to the polysaccharide) having the maximum swelling capacity was obtained after 85‐h crosslinking reaction. The reaction mixture developed a dark blue color with the passage of time, indicating thereby the progress of the crosslinking reaction in presence of genipin. The maximum swelling of the genipin‐fixed agarose hydrogel in acidic medium at pH 1.2 was ∼ 48 g/g, whereas the parent polysaccharide agarose achieved equilibrium swelling state at 6 g/g. The genipin‐fixed agarose showed 30% weight loss in Ringer's solution, while the agarose polysaccharide exhibited ∼ 50% weight loss in the same medium, both after 60 days. The thermogravimetric analysis studies revealed enhanced thermal stability of the genipin‐fixed agarose hydrogel. In view of the enhanced stability and swelling capacity of the genipin‐fixed agarose compared to agarose, the value added polysaccharide may be useful in new applications as super absorbents and in biomedical applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 290–296, 2007