RADIATION-INDUCED GRAFT-COPOLYMERIZATION OF SOME VINYL MONOMERS ONTO WASTE RUBBER POWDER

Rubber powder was subjected to graft copolymerization with different v inyl monomers such as acrylamide (AAm), acrylic acid (AAc), and acrylo nitrile (AN). Graft copolymerization of these monomers onto rubber pow der was carried out using gamma radiation. The effects of different pa rameters such as monomer concentration, radiation dose, inhibitor conc entration, and type of reaction solvent on the graft yield were studie d. It was found that the maximum graft yield obtained is 90%, 24%, and 42% for AAc, AAm, and AN, respectively. The grafted rubber powder obt ained was tested as ion exchanger for copper and lead, and its capacit y for ion recovery was found to be dependent on the type of monomer an d graft yield. For instance, polyacrylamide and sodium salt of polyacr ylic acid grafted onto rubber powder are more efficient as ion exchang ers for both copper and lead ions than polyacrylonitrile. Amidoxime de rivative of polyacrylonitrile is more efficient as ion exchanger than the parent polyacrylonitrile.