Enhanced amination and adsorption performance of functional copolymer synthesized via RAFT-mediated radiation grafting in emulsion

Grafted polymer substrates bearing diglycol amic acid (DA) ligands for Eu and Sm adsorption were prepared using a two-step post-grafting modification of polyethylene/polypropylene-g-poly(glycidyl methacrylate) (PE/PP-g-PGMA) that was synthesized through reversible addition-fragmentation chain transfer (RAFT)-mediated γ-radiation induced graft polymerization in emulsion phase. The PE/PP-g-PGMA prepared with RAFT mediation exhibited better reactivity towards amination reaction at 40 °C than the graft copolymers prepared without RAFT mediation, with the epoxide to amino group conversion of the former exceeding the latter by as much as 20%. The DA ligands were incorporated to the aminated graft copolymer by subsequent reaction with diglycolic anhydride to yield the DA-modified PE/PP-g-PGMA adsorbent. The effects of pH and competing ions on the uptake of Eu and Sm have been investigated. The DA-modified PE/PP-g-PGMA prepared with RAFT mediation showed higher Eu and Sm adsorption percentage than the DA adsorbent that was synthesized without RAFT mediation. The DA-modified PE/PP-g-PGMA exhibited higher affinity for Eu over Cu and Fe in acidic solutions.