Synthesis and characterization of biodegradable pH-sensitive hydrogel based on poly(ε-caprolactone), methacrylic acid, and Pluronic (L35)

A series of biodegradable and pH-sensitive hydrogels based on poly(ε-caprolactone) (PCL), Pluronic, and methylacrylic acid (MAA) were successfully prepared by UV-initiated free radical polymerization, which were further characterized by 1H NMR and FTIR. Swelling behavior in different aqueous media and pH-responsibility of the hydrogels were studied in detail. With increase in pH value of aqueous media from 1.2 to 7.2, swelling ratio of the hydrogels increased accordingly. The hydrolytic degradation behavior of these hydrogels was also investigated in detail. The biodegradable pH-sensitive hydrogel obtained in this work might have great potential application in drug delivery system.