Preparation of macroporous cellulose-based superabsorbent polymer through the precipitation method

Superabsorbent polymer was prepared by graft polymerization of acrylic acid onto the chain of carboxymethyl cellulose. This superabsorbent polymer was further treated by the solvent precipitation method. We found that the water absorption rate of the treated polymer was greatly increased and the microstructure of the treated polymer was changed from close-grained structures to loose macropores. The swelling processes of the polymers before and after modification fit first-order dynamic processes. The amount of the residual acrylic acid was detected through high performance liquid chromatography (HPLC) with aqueous solution of MOPS of 0.02mol/L (pH=5.70) as the mobile phase. It was found that the amount of the residual acrylic acid decreased from 83.8 × 10^-4% to 6.7 × 10^-4% after treatments.