A series of porous poly(N—isopropylaerylamide-co—acrylic acid)[P(NIPA—co一AA)]hydrogels were prepared by radical polymerization using PEG400

1000

6000 as pore-forming agents during the reaction process．SEM macrographs revealed that the pore size of the hydmgels could be modulated by adjusting the molecular weight or the amount of PEG．The swelling ratio of the porous gels at room temperature was higher than that of the conventional P(NIPA—co-AA)hydregels due to the porous micrestructure．When the hydrogels were transferred to an aqueous medium of 60℃．they shrank rapidly to an equilibrium state and exhibited faster response properties．What’s more

the swelling ratio and responsive rate increased with elevating the molecular weight or the amount of PEG．The prepared mocreporeus hydmgels have potential applications in controlled release of macromolecular active agents．