Urazole as an unorthodox functional group for fabrication of anionic hydrogels and ion-exchange materials

In this study, highly ionazable protons (pKa 5-6) of urazole were exploited to obtain an anionic hydrogel in two simple and scalable steps. Commercially available multiisocyanate, poly(hexamethylene)diisocyanate, was used to prepare urazole containing gel. Urazole formation was confirmed by FT-IR and 1H-NMR spectroscopy. The hydrogel were characterized by microscopy imaging, spectroscopic and gravimetric analysis. Mechanical analysis and cell viability test were performed for its initial biocompatibility evaluation. The prepared hydrogel is a highly porous hydrogel with a Young’s modulus of 0.91MPa, has swelling ratio of 87% and capable of exchanging ions in a medium. In this report, we demonstrated a strategy to overcome synthetic challenge of incorporating urazole into a material via precursor path rather than attempting to embeding urazole groups directly.