Synthesis And Properties Of Temperature And Ph-sensitive N-isopropyl Acrylamide / ¦Â-cyclodextrin Hydrogels

A novel functional monomer (MAH-β-CD) containing vinyl and carboxyl groups was synthesized by reaction ofβ-cyclodextrin (β-CD) with maleic anhydride (MAH). By copolymerization of MAH-β-CD with N-isopropylacrylamide (NIPA) and sodium acrylate (SA) using N, N'-mcthylcne-bisacrylamide (BIS) as the crosslinker in aqueous solution, a new hydrogel [poly(MAH-β-CD-co-NIPA)] with pH anti temperature sensitivities was obtained. The MAH-β-CD monomer and the hydrogels obtained were characterized by using IR spectra and ¹³C-NMR, the Lower Critical Solution Temperature (LCST) of the hydrogels were determined by differential scanning calorirnctry (DSC) methods.The equilibrium swelling ratios (ESR) of the hydrogels had been investigated under conditions of different pH and temperature. The results indicated that the ESR presented remarkable response to changcs of pH and temperature. The LCST of the hydrogels deeply depended on its composition especially the SA content, but had nothing with the crosslinker content.