Novel itaconic acid-based superabsorbent polymer composites using oxidized starch

Abstract

It is essential to enhance gel strength and absorption properties of biomass-derived itaconic acid-based superabsorbent polymer (SAP) to commercialize it. We prepared novel poly(itaconic acid-co-acrylic acid) SAP composites via in-situ aqueous solution copolymerization with oxidized starch (OS) as a filler. The structure of the SAP composite is characterized using Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction. In addition, the absorption properties of the SAP composites with various OS contents, crosslinker contents (1, 6-hexanediol diacrylate) and degrees of monomer neutralization are evaluated by measuring the free absorbency, centrifuge retention capacity, and absorbency under load in saline solution. The gel contents are measured after extraction of the unreacted monomers and oligomers, and their morphologies are examined by scanning electron microscopy and BET analyzer. Finally, optimal results were compared with response surface methodology (RSM). Thus, the optimal polymerization conditions of the SAP composites of 85 g are identified as an OS content of 4.5 g, a crosslinker content of 2.0 g, and a 75% degree of neutralization. And optimal SAP provide performance indicated by a CRC of 55.7 g/g and an AUL of 10.2 g/g.