Synthesis of ABC-type miktoarm star polymers by click chemistry, ATRP and ROP

ABC-type miktoarm star polymers, poly(ethylene oxide)-block-polystyrene-block-poly (epsilon-caprolactone)s (PEO-b-PS-bPCL) were synthesized via combination of click chemistry, atom-transfer radical polymerization (ATRP) and ring opening polymerization (ROP). Azide ended PEO arms, PEO-N-3, and a trifunctional molecule, propargyl 2-hydroxylmethyl-2-(alpha-bromoisobutyraloxymethyl)-propionate (PHBP), were prepared first, respectively. A click reaction of PEO-N-3 and PHBP generated a PEO inacroinitiator, PEO-(Br)(OH) with two functionalities, one is hydroxyl group and the other is (alpha-bromoisobutyraloxyl group. Consecutive ATRP of styrene (St) and ROP epsilon-caprolactone (epsilon-CL) from the PEO macroinitiator produced the PEO-b-PS-b-PCL miktoarm stars. All the structures of the polymers were determined. (C) 2007 Elsevier Ltd. All rights reserved.