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.