A Novel IPN Hydrogel Based on Poly (N‐Isopropylacrylamide) and β‐Cyclodextrin Polymer

A novel interpenetrating polymeric network (IPN) was prepared based on poly (N‐isopropylacrylamide) (PNIPA) and β‐cyclodextrin (β‐CD) polymer with two steps of polymerization techniques. A β‐CD polymer (β‐CD‐EPI‐PVA) was first synthesized by reaction of β‐CD with epichlorohydrin (EPI) in diluent poly(vinyl alcohol) (PVA) aqueous solution, and the IPN was synthesized via dispersing NIPA monomer into the β‐CD polymer, polymerized, and crossliked in situ. Infrared spectroscopy, element analysis, DSC, TGA, and swelling measurements were used to characterize the structures of β‐CD‐EPI‐PVA polymer and related IPN hydrogel. The results indicated that equilibrium swelling ratio (ESR) of the β‐CD‐EPI‐PVA network decreases gradually with the increase in temperature. The volume phase transition temperature (T v) of IPN hydrogel is still sensitively kept at about 33°C.