PHEA-g-PDMAEA well-defined graft copolymers: SET-LRP synthesis, self-catalyzed hydrolysis, and quaternization

Abstract

Two well-defined graft copolymers consisting of a hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) backbone and poly(2-dimethylamino ethylacrylate) (PDMAEA) side chains were synthesized by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization and single-electron-transfer living radical polymerization (SET-LRP) via the grafting-from strategy. A trifunctional 2-hydroxyethyl 2-((2-chloropropanoyloxy)methyl)acrylate monomer comprising a –COCH(CH₃)Cl SET-LRP initiating group was first RAFT homopolymerized to give a PHEA-based homopolymer bearing a Cl-containing SET-LRP initiating group in every repeated unit with a narrow molecular weight distribution (M_w/M_n = 1.08). This homopolymer directly initiated SET-LRP of 2-(dimethylamino)ethyl acrylate for affording the target well-defined poly(2-hydroxyethyl acrylate)-graft-poly(2-dimethylamino ethylacrylate) (PHEA-g-PDMAEA) graft copolymers (M_w/M_n ≤ 1.17) with hydroxyl in every repeated unit of the backbone without polymeric functionality transformation. The obtained water-soluble graft copolymers could self-hydrolyze in neutral and basic aqueous solutions at ambient temperature without external stimuli. Furthermore, PHEA-g-PDMAEA can be quaternized in aqueous media so as to aggregate into reversed micelles in the organic phase.