Synthesis, Functionalization and Reductive Degradation of Multibrominated Disulfide-containing Hyperbranched Polymers

Abstract

Reductively degradable hyperbranched polymethacrylates with multiple peripheral alkyl bromide groups were synthesized by the azobis(2-isobutyronitrile)-initiated copolymerization of diethylene glycol methyl ether methacrylate or oligo(ethylene oxide) methyl ether methacrylate with the disulfide-containing crosslinker bis(2-methacryloyloxyethyl)disulfide (2.5–10.0 mol-% relative to the monomer) in the presence of carbon tetrabromide (10–40-fold excess relative to the radical initiator) as efficient chain transfer agent. The alkyl bromide groups initiated the atom-transfer radical polymerization of methyl methacrylate, and star copolymers with hyperbranched disulfide-containing cores were formed. Both the macroinitiators and the star copolymers derived from them were degraded in reducing environment.