초록 |
Microspheres of poly(N-isopropylacrylamide-co-n-butoxymethylacrylamide) (Poly(NIPAAm-co-nBMA)) and poly(N-isopropylacrylamide-co-acrylic acid) (Poly(NIPAAm-co-AAc)), cross-linked with N-N'-methylene-bisacrylamide (NMBA), were synthesized using precipitation polymerization. Through the differencial scanning calorimeter, dynamic light scattering, SEM analysis, Tc and diameter of the microspheres were determined. The effects of temperature and pH changes have been investigated for the hydrogels containing the comonomer. Both poly(NIPAAm-co-nBMA) and poly(NIPAAm-co-AAc) MIS are temperature sensitive. Variations in pH were found to effect the size of poly(NIPAAm-co-AAc) MIS which contained the ionizable groups such as carboxyl groups due to the increased electrostatic repulsion of charged groups. |