Swelling Behavior of Carboxymethyl cellulose-g-PMAAm-co-PNIPAm Superabsorbent Hydrogels

A novel superabsorbent hydrogel was synthesized via crosslinking graft copolymerization of N-isopropylacrylamide (NIPAAm) and methacrylamide (MAAm) onto Carboxymethyl cellulose (CMC) backbones in a homogeneous solution. The methylenebisacrylamide (MBA) and amounium persulfate (APS) were used as water-soluble crosslinker and initiator respectively. Evidence of grafting was obtained by comparing FTIR, SEM spectra of CMC and the graft copolymer as well as solubility characteristics of the products. A mechanism for the superabsorbent hydrogel formation was also suggested. The effect of MBA, APS, CMC concentration and MAAm/NIPAAm weight ratio on the water absorbency capacity has been investigated. The swelling variations of hydrogels were explained according to swelling theory based on the hydrogel chemical structure. The temperature-sensitivity properties of the hydrogels also make the intelligent polymers as good candidates for considering as potential carriers for bioactive agents e. g. drugs.