High Yield Synthesis of Molecular Brushes via ATRP in Miniemulsion

Abstract

Molecular brushes were successfully synthesized in miniemulsion systems via activators generated by electron transfer (AGET) ATRP. Confinement of the polymerization reaction within miniemulsion droplets (Dhydro = 275 ± 10 nm) effectively avoided the problem of macroscopic gelation observed in bulk polymerization. The side-chain polymers grew rapidly from the backbones within the droplets which resulted in high monomer conversion in a relatively short time. Molecular visualization by AFM proved that a small amount of cross-linking did occur only at high monomer conversions. However, this microscopic gelation showed no effect on the miniemulsion stability, and therefore the synthesized materials can still be easily used. Thus, the miniemulsion approach leads to preparation of polymer brushes in higher yields as compared to bulk or solution processes.