Superabsorbent polymeric materials VII: Swelling behavior of crosslinked poly[sodium acrylate-co-trimethyl methacrylamido-propyl ammonium iodide] in aqueous salt solutions

A series of xerogels based on sodium acrylate (SA), cationic comonomer trim ethyl methacrylamidopropyl ammonium iodide (TMMAAI), and N,N-methylene-bis- acrylamide (NMBA) were prepared by inverse suspension polymerization. The w ater absorbency and the swelling behavior for these highly absorbent polyme rs in deionized water and various saline solutions were investigated. Resul ts indicated that the water absorbency increased when a small amount of TMM AAI monomer was introduced into the SA gel. The water absorbency decreased with increase in TMMAAI content, but the contrary result was observed for i nitial absorption rate. Moreover, with more crosslinking agent, the water a bsorbency was lower. Finally, the adsorption of copper ion by these gels wa s also investigated. (C) 2000 John Wiley & Sons, Inc.