Synthesis of poly(ethylene oxide) with pending 2,2,6,6- tetramethylpiperidine-1-oxyl groups and its further initiation of the grafting polymerization of styrene

A new stratagem for the synthesis of amphiphilic graft copolymers of hydrophilic poly(ethylene oxide) as the main chain and hydrophobic polystyrene as the side chains is suggested. A poly(ethylene oxide) with pending 2,2,6,6-tetramethylpiperidine-1-oxyls [poly(4-glycidyloxy-2,2,6,6- tetramethylpiperidine-1-oxyl-co-ethylene oxide)] was first prepared by the anionic ring-opening copolymerization of ethylene oxide and 4-glycidyloxy-2,2,6, 6-tetramethylpiperidine-1-oxyl, and then the graft copolymerization of styrene was completed with benzoyl peroxide as the initiator in the presence of poly (4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl-co-ethylene oxide). The polymerization of styrene was under control, and comblike, amphiphilic poly(ethylene oxide)-g-poly styrene was obtained. The copolymer and its intermediates were characterized with size exclusion chromatography, ¹H NMR, and electron spin resonance in detail.