Synthesis of cassava starch-g-acrylic acid/dimethylaminopropyl methacrylamide: A new hydrogel for brine solution

A new hydrogel copolymer was synthesized via the graft copolymerization of acrylic acid (AA) and dimethylaminopropyl methacrylamide (DMAPMA) on cassava starch (CSt) in aqueous solution. FTIR, TGA-FTIR, solid-state ¹³C NMR, SEM analyses were used to characterize the polymer. The swelling behavior of the polymer was investigated in distilled water and in various brine solutions. The effects of CSt and the ratio of the two monomers on the water absorbency of the polymer was evaluated. CSt improved the polymer swelling properties. Both polyelectrolyte and anti-polyelectrolyte effects occurred and the polymer had good salt-resistance properties in brine solutions. Such polymers have potential applications in the absorption of ultra-high concentration brine solutions.