SEARCH

SEARCH BY CITATION

Keywords:

  • atom transfer radical polymerization (ATRP);
  • “Click” chemistry;
  • graft copolymers;
  • hyperbranched poly(glycerol) (HPG);
  • ring-opening polymerization (ROP)

Abstract

The graft copolymers composed of “Y”-shaped polystyrene-b-poly(ethylene oxide)2 (PS-b-PEO2) as side chains and hyperbranched poly(glycerol) (HPG) as core were synthesized by a combination of “click” chemistry and atom transfer radical polymerization (ATRP) via “graft from” and “graft onto” strategies. Firstly, macroinitiators HPG-Br were obtained by esterification of hydroxyl groups on HPG with bromoisobutyryl bromide, and then by “graft from” strategy, graft copolymers HPG-g-(PS-Br) were synthesized by ATRP of St and further HPG-g-(PS-N3) were prepared by azidation with NaN3. Then, the precursors (Bz-PEO)2-alkyne with a single alkyne group at the junction point and an inert benzyl group at each end was synthesized by sequentially ring-opening polymerization (ROP) of EO using 3-[(1-ethoxyethyl)-ethoxyethyl]-1,2-propanediol (EEPD) and diphenylmethylpotassium (DPMK) as coinitiator, termination of living polymeric species by benzyl bromide, recovery of protected hydroxyl groups by HCl and modification by propargyl bromide. Finally, the “click” chemistry was conducted between HPG-g-(PS-N3) and (Bz-PEO)2-alkyne in the presence of N,N,N′,N″,N”-pentamethyl diethylenetriamine (PMDETA)/CuBr system by “graft onto” strategy, and the graft copolymers were characterized by SEC, 1H NMR and FTIR in details. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010