Temperature-sensitive hydrogel prepared by graft polymerization of N-isopropylacrylamide onto macroradical Pluronic

A new series of thermo-responsive graft copolymers were prepared via consecutive Pluronic backbone-initiated by t-butylperoxybenzoate with N-isopropylacrylamide (NIPAAm) onto Pluronic by a radical-induced graft polymerization technique. The thermal characterizations of the graft copolymers were investigated by differential scanning calorimetry (DSC). The Pluronic-g-poly(NIPAAm) copolymers exhibited sol-to-gel transitions depending on chain length of the grafted poly(NIPAAm) onto Pluronic. The graft copolymers indicated that the hydrophobic–hydrophilic balance achieved by varying contents of NIPAAm was an important parameter in controlling the transition temperature of the graft copolymers in solution and stability of the resultant gels. The data suggest that graft copolymers may be attractive substrates for tissue engineering and drug delivery applications as the combination of mechanistically independent gelation techniques with regard to gelation kinetics.