Effect of two comonomers on salt tolerance of starch/sodium polyacrylate superabsorbent

Starch-based super absorbent polymers (SAPs) were prepared using the gamma-ray co-irradiation method, where two comonomers were grafted and cross-linked. Incorporation acrylamine (AM) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) into the SAP was confirmed using Fourier transform infrared spectroscopy. The thermal decomposition behavior of the SAP was studied using thermogravimetric analysis. The salt tolerance was significantly improved by introducing AM and AMPS monomers into the SAP. The absorption rate of the SAP with AMPS in normal saline increased from 46 g/g (without AMPS) to 81 g/g when the ratio of AA:AMPS was 3:1.