Poly(N

N-dimethylacrylamide-co-N-isopylacrylamide) ［P(DMAA-co-NIPAm)］ hydrogels have been prepared by photopolymerization technique in the solvent of H2O at different temperatures (50℃ and 28℃) respectively

and N

N′-methylene bisacrylamide (Bis) was used as the cross-linking agent.The Comparing performances of the hydrogels (P2) synthesized at 50℃with that (P1) at 28℃ by the photo-induced polymerization have been investigated in cluding the network structure

swelling and shrinking behavior

temperature-sensitive behavior and so on.The results show that the hydrogels (P2) synthesized at 50℃exhibit a structure different from that of hydrogels (P1) and exhibit fast responsive properties and more excellent water release behavior (shrinking behavior) at high temperature.The reasons causing the property improvement of the hydrogels were discussed.The products were characterized by Fourier transform infrared(FTIR) spectroscopy and scanning electron microscopy(SEM).Swelling dynamics

water release behavior and temperature-sensitive performances of the hydrogels were discussed.The synthetic procedure of the photo-induced copolymerization was quickly finished within two minutes.