A Novel Thermo-Sensitive Polymer. Poly(2-iso-propyl-2-oxazoline)

Poly(2-iso-propyl-2-oxazoline) (PiPrOZO), prepared by cationic ring-opening polymerization of iPrOZO, has been found to be a thermo-sensitive polymer. PiPrOZO possesses a cloud point (CP) around 36 °C. The CP changed by the addition of sodium chloride or a surfactant. For utilizing these characteristics, a new hydrogel was prepared by copolymerization of a PiPrOZO macromonomer with ethylene glycol dimethacrylate. The hydrogel swelled below the CP of PiPrOZO. Above the CP, on the other hand, the degree of swelling of the gel was very low.