Synthesis of asymmetric H-shaped block copolymer by the combination of atom transfer radical polymerization and living anionic polymerization

A new asymmetric H-shaped block copolymer (PS)2–PEO–(PMMA)2 has been designed and successfully synthesized by the combination of atom transfer radical polymerization and living anionic polymerization. The synthesized 2,2-dichloro acetate-ethylene glycol (DCAG) was used to initiate the polymerization of styrene by ATRP to yield a symmetric homopolymer (Cl–PS)2–CHCOOCH2CH2OH with an active hydroxyl group. The chlorine was removed to yield the (PS)2–CHCOOCH2CH2OH ((PS)2–OH). The hydroxyl group of the (PS)2–OH, which is an active species of the living anionic polymerization, was used to initiate ethylene oxide by living anionic polymerization via DPMK to yield (PS)2–PEO–OH. The (PS)2–PEO–OH was reacted with the 2,2-dichloro acetyl chloride to yield (PS)2–PEO–OCCHCl2 ((PS)2–PEO–DCA). The asymmetric H-shaped block polymer (PS)2–PEO–(PMMA)2 was prepared via ATRP of MMA at 130 °C using (PS)2–PEO–DCA as initiator and CuCl/bPy as the catalyst system. The architectures of the asymmetric H-shaped block copolymers, (PS)2–PEO–(PMMA)2, were confirmed by 1H NMR, GPC and FT-IR.