Superabsorbent nanocomposite based on methyl acrylic acid-modified bentonite and sodium polyacrylate: Fabrication, structure and water uptake

Highlights: • Methyl acrylate groups were chemically bonded onto the surface of layers. • Individually dispersed MAABT showed an acicular structure. • A high water absorbency was achieved, as high as 1287 g/g in distilled water. • Double bonds participate in polymerization to enhance compatibility of PAA/MAABT. • MAABT served as a reinforcing agent and crosslink joint to enhance the cross-linked network. The present study demonstrates a feasible synthetic route to prepare a methyl acrylic acid-modified bentonite (MAABT)/sodium polyacrylate (SPA) superabsorbent nanocomposite, in which the MAABT serves as a reinforcing agent for SPA, as well as a cross-linking joint to enhance the network of the nanocomposite. The interfacial compatibilization effect of the MAABT was understood by copolymerization of sodium acrylate and methyl acrylate groups which were chemically bonded on the surface of bentonite. With the fine dispersion of MAABT and strong interfacial interaction, the MAABT/SPA nanocomposite achieved a water absorbency that was as high as 1287 g/g under accurate controls. Additionally, it comes out that the thermal stability and water retention capacity of the nanocomposites were also improved with the incorporation of MAABT. The suggested method for reactive compatibilization of MAABT and SPA may offer routes to the design of new organic–inorganic nanocomposites for various applications.