Study on Superabsorbent Composite XXV. Synthesis, Characterization, and Swelling Behaviors of Poly(acrylic acid-co-N-acryloylmorpholine)/Attapulgite Superabsorbent Composites

In this work, a novel poly(acrylic acid-co-N-acryloylmorpholine)/attapulgite superabsorbent composite was prepared by graft copolymerization among acrylic acid, N-acryloylmorpholine and attapulgite in aqueous solution, using N,N'-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. The result from FTIR spectra showed that -OH of attapulgite participated in graft copolymerization with acrylic acid and N-acryloylmorpholine. Proper monomer ratio and atapulgite content could form a loose surface, and improve reswelling ability and initial swelling rate. The buffer action of the -COOH and -COO- groups in the superabsorbent composite keeps the water absorbency a rough constant in the pH range of 4.4-9.6. Both polarity and structure of an organic solvent are responsible for the phase transition point of the superabsorbent composite. POLYM. COMPOS., 31:691-699, 2010. (C) 2009 Society of Plastics Engineers