Synthesis of 4μ-PS₂PEO₂, 4μ-PS₂PCL₂, 4μ-PI₂PEO₂, and 4μ-PI₂PCL₂ star-shaped copolymers by the combination of glaser coupling with living anionic polymerization and ring-opening polymerization

Abstract

4μ-A₂B₂ star-shaped copolymers contained polystyrene (PS), poly(isoprene) (PI), poly(ethylene oxide) (PEO) or poly(ε-caprolactone) (PCL) arms were synthesized by a combination of Glaser coupling with living anionic polymerization (LAP) and ring-opening polymerization (ROP). Firstly, the functionalized PS or PI with an alkyne group and a protected hydroxyl group at the same end were synthesized by LAP and then modified by propargyl bromide. Subsequently, the macro-initiator PS or PI with two active hydroxyl groups at the junction point were synthesized by Glaser coupling in the presence of pyridine/CuBr/N,N,N ′,N ″,N ″-penta-methyl diethylenetri-amine (PMDETA) system and followed by hydrolysis of protected hydroxyl groups. Finally, the ROP of EO and ε-CL monomers was carried out using diphenylmethyl potassium (DPMK) and tin(II)-bis(2-ethylhexanoate) (Sn(Oct)₂) as catalyst for target star-shaped copolymers, respectively. These copolymers and their intermediates were well characterized by SEC, ¹H NMR, MALDI-TOF mass spectra and FT-IR in details. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010