Abstract
Copolymers were prepared by gamma irradiation of acrylic acid (AAc)/plasticized starch (PLST)/carboxymethyl cellulose (CMC) mixtures in aqueous solutions. The effect of AAc ratio and gamma irradiation dose on the gel content, swelling (%) and tensile mechanical properties was investigated. The PAAc-co-PLST/CMC copolymers were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and surface morphology by scanning electron microscopy (SEM). The thermal stability was further investigated by determining the activation energy by three different methods based on Coats-Redfern, Broido and the Horowitz –Metzger approximation equations. As an application, the removal of copper and nickel ions by the copolymer hydrogel was also studied. The results indicated that the graft copolymer hydrogels have higher affinity for Ni+2 than Cu+2 ions.