Synthesis of diamide-based resin for selective separation of 99Tc

N , N , N ′, N ′-tetramethylmalonamide (TMMA) has been successfully grafted onto the chloroacetylated poly(styrene-co-divinylbenzene) resin to obtain a novel diamide-based resin (PS–TMMA). PS–TMMA exhibited high adsorption capacity and selectivity toward TcO 4 − in 0.1–1 M HCl. The adsorption process of PS–TMMA conforms (Revise: conformed) to Langmuir isotherm and pseudo-second-order kinetics model. The results of column experiments revealed TcO 4 − can be completely separated from the coexisting fission products (Sr(II), Eu(III), Dy(III), and 1 M NH 3 ·H 2 O can re-collect TcO 4 − absorbed in the resin column. The adsorption mechanism of TcO 4 − is considered that PS–TMMA is converted into anion exchange resin in acidic condition.