Phase Transition Behavior of Poly(N-isopropylacrylamide-co-N,Ndimethylaminopropylacrylamide) Hydrogels

Abstract

The copolymer hydrogel of N-isopropylacrylamide (NIPAAm) and N,N-dimethylaminopropylacrylamide (DMAPAA) was synthesized by free radical copolymerization. The phase transition behavior of p(NIPAAmco-DMAPAA) hydrogels as a function of temperature and SDS concentration was studied. The p(NIPAAmco-DMAPAA) hydrogels exhibited larger swelling capacity than the homo p(NIPAAm) hydrogel. The phase transition temperature of p(NIPAAm-co-DMAPAA) hydrogels increased with an increase of DMAPAA content. In aqueous SDS solution, the swelling capacity of p(NIPAAm-co-DMAPAA) hydrogel decreased with an increase of SDS concentration. The phase transition temperature of p(NIPAAm-co-DMAPAA) hydrogels was found to be almost independent of the SDS concentration.