Showing papers by "Kazutoshi Haraguchi published in 2003"

Compositional effects on mechanical properties of Nanocomposite hydrogels composed of poly(N, N-dimethylacrylamide) and clay

Abstract: Nanocomposite type hydrogels (DMAA-NC gels) consisting of organic (polymer)/inorganic (clay) networks were prepared by in-situ free-radical polymerization of N,N-dimethylacrylamide (DMAA) in the presence of inorganic clay in aqueous solution. The composition of the NC gels could be controlled directly by altering the composition of the initial reaction mixture. The resulting DMAA-NC gels were mostly uniform and transparent, irrespective of their clay and polymer contents. From DSC, X-ray, TEM, and tensile mechanical measurements, the network structure was established. Contrary to conventional chemically cross-linked hydrogels (DMAA-OR gels) prepared by chemical cross-linking with a difunctional monomer, DMAA-NC gels exhibit superb mechanical properties with astonishingly large elongations at break, near to or greater than 1500%. The effects of the composition, such as the amounts of clay, polymer, and water content in DMAA-NC gels, on the tensile mechanical properties were investigated in detail. With inc...