Interpenetrating Polymer Networks of Poly(N-vinylacetamide) and Stimuli Responsive Polymers Applied to Novel Amphiphilic Gel

The swelling behaviors of IPN with poly(N-vinylacetamide) (PNVA), which possibly converts from nonionic gel to cationic gel, and the stimuli responsive polymers, such as poly(acrylic acid) (PAAc) and poly(N-isopropylacrylamide) (PNIPAm) were investigated in order to prepare the stimuli responsive amphiphilic gel. When the monomer concentrations were uniformed at the IPN preparation, the obtained PNVA/PAAc IPN showed the pH responsivity with around 100 of swelling ratio at pH 4 to around 1 of swelling ratio at pH 2, although it lost the amphiphilicity due to the lack of swelling in ethanol. On the other hand, the gelation of N-vinylacetamide at 2 M in PNIPAM gel resulted in thermosensitive and amphiphilic hydrogel, that the swelling ratio in EtOH/water (3/7, v/v) also decreased, compared to the value in water at 25 degrees C.