NOVEL NONIONIC AND CATIONIC HYDROGELS PREPARED FROM N-VINYLACETAMIDE

Poly(N-vinylacetamide) (polyNVA) hydrogels were prepared by the copolymerization of N-vinylacetamide (NVA) with divinyl compounds such as methylene-bis-acrylamide, methylene-bis-NVA, and butylene-bis-NVA in a high yield. The resulting hydrogels were more stable than polyacrylamide gel and showed quite a high swelling property in a wide range of pH (1-12) and even in a 5M NaCl solution. They showed not only typical characteristics nonionic hydrogels, but also an amphiphilic property and they swelled well in some organic solvents. When the gels were partially hydrolyzed, cationic hydrogels, i.e., crosslinked poly(NVA-co-vinylamine), were collected. The resulting superabsorbent hydrogels absorbed 400 times of water.