Synthesis of well-defined amphiphilic graft copolymer bearing poly(2-acryloyloxyethyl ferrocenecarboxylate) side chains via successive SET-LRP and ATRP

Abstract

A series of well-defined ferrocene-based amphiphilic graft copolymers, consisting of poly(N-isopropylacrylamide)-b-poly(ethyl acrylate) (PNIPAM-b-PEA) backbone and poly(2-acryloyloxyethyl ferrocenecarboxylate) (PAEFC) side chains, were synthesized by the combination of single-electron-transfer living radical polymerization (SET-LRP) and atom transfer radical polymerization (ATRP). A new ferrocene-based monomer, 2-(acryloyloxy)ethyl ferrocenecarboxylate (AEFC), was prepared first and it can be polymerized via ATRP in a controlled way using methyl 2-bromopropionate as initiator and CuBr/PMDETA as catalytic system in DMF at 40 °C. PNIPAM-b-PEA backbone was synthesized by sequential SET-LRP of NIPAM and HEA at 25 °C using CuCl/Me6TREN as catalytic system followed by the transformation into the macroinitiator by treating the pendant hydroxyls with α-bromoisobutyryl bromide. The targeted well-defined graft copolymers with narrow molecular weight distributions (Mw/Mn < 1.20) were synthesized via ATRP of AEFC initiated by the macroinitiator. The electro-chemical behaviors of PAEFC homopolymer and PNIPAM-b-(PEA-g-PAEFC) graft copolymer were studied by cyclic voltammetry. Micellar properties of PNIPAM-b-(PEA-g-PAEFC) were investigated by transmission electron microscopy and dynamic light scattering. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4346–4357, 2009