Synthesis and characterization of radiopaque iodine-containing methacrylate-based polymers via reversible addition-fragmentation chain transfer (RAFT) polymerization

The reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-(2′-iodobenzoyl) ethyl methacrylate (2-IEMA) was performed in benzene solution using 4-cyanopentanoic acid dithiobenzoate (CPADB) as chain transfer agent to yield well-defined iodine-containing methacrylate-based polymers. It is characteristic of a controlled/living polymerization, i. e., linear increase in M_n with conversion and narrow molecular distribution. Moreover, the block copolymerization of 2-IEMA with 2-(2′,3′,4′,6′-tetra-O-acetyl-β-Dglucosyloxy) ethyl methacrylate (AcGEMA) and 2-lactobionamidoethyl methacylate (LAMA) was also carried out to give radiopaque glycopolymers by using the same methodology, respectively. The radiopacity of these polymers was evidenced by a routine medical X-ray imaging technique. TEM and DLS analytical results showed that the selected PIEMA-b-PLAMA diblock copolymers can self-assemble in aqueous solution into nearly spherical aggregates of 60-86 nm in diameter.