Inorganic clay-enhanced cellulose-based superabsorbent composites on swelling performance and responsive behavior

The inorganic clay had a significant impact on the properties of superabsorbent composites (SACs). In this study, the alkali-urea system pretreated bamboo pulp fibers were used as raw material, acrylic acid (AA), acrylamide (AM) and 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) as hydrophilic monomers. By using reverse suspension polymerization to incorporate sepiolite (ST), acid-treated sepiolite (AST), montmorillonite (MMT) and acid-treated montmorillonite (AMMT) into superabsorbent materials, four SACs were effectively fabricated. Results showed that the water absorbency of the SACs was: SACs/AST＞SACs/AMMT＞SACs/MMT＞SACs/ST, and the saline absorbency was: SACs/AMMT＞SACs/AST＞SACs/MMT＞SACs/ST. The highest liquid absorbency was 1292.2 g/g (water absorbency) and 134.4 g/g (saline absorbency). The resultant SACs presented excellent swelling performance, swelling repeatability, and high temperature water retention rate. Furthermore, the SACs also had outstanding responsive behavior in physiological saline and pH 2.0 solution. • Cellulose-based superabsorbent polymer was modified by inorganics of AST and AMMT. • The clay improved the swelling performance and responsive behavior of SACs. • The liquid absorbency of SACs can reach 1292.2 g/g (water) and 134.4 g/g (saline). • SACs/AST had the highest water absorbency and fast swelling performance (10 min). • SACs/AMMT had the best saline absorbency and remarkable swelling repeatability.