Preparation and thermosensitive property of rapid responsive P(NIPA-co-SA) hydrogels

Temperature sensitive hydrogel with high LCST and rapid responsiverate was studied. The porous hydrogel P(NIPA-co-SA) was synthesized by phase separation method with Na Cl solution as reaction medium. The structure of product was identified by FT-IR. The influences of the reaction medium concentration on microstructure,LCST and phase transformation response rate of productswere studied by scanning electron microscope,differential scanning calorimetry(DSC) and turbidity method. The results show that P(NIPA-co-SA) hydrogel has sensitive response to temperature,which LCST was up to about 75 ℃. The concentration of Na Cl solution doesn't influence the LCST of product.However,along with the increase of Na Cl concentration,shallow discontinuous airtight ostioles gradually appear on the surface of hydrogel,which change to open pores throughout each other. The phase transformation response rate of hydrogel gradually increases in certain degree,which has rapid response character.