Synthesis and characterization of poly(vinyl alcohol-b-styrene)via atom transfer radical polymerization and saponification

Abstract

Poly(vinyl alcohol-b-styrene) (poly(VA-b-St)) diblock copolymer containing high syndiotactic poly (vinyl alcohol) (PVA) was synthesized by the saponification of poly(vinyl pivalate-b-styrene) (poly(VPi-b-St)). For the block copolymer, poly(vinyl pivalate) (PVPi) with trichloromethyl end group was obtained via telomerization of vinyl pivalate with carbon tetrachloride as a telogen and 2,2-azobisisobutyronitrile (AIBN) as an initiator. Then resulting poly(vinyl pivalate) with trichloromethyl end group was used as an efficient macroinitiator for the synthesis of poly(VPi-b-St) using atom transfer radical polymerization (ATRP) in the presence of CuCl/2,2′-bipyridine at 130 °C. The poly(vinyl pivalate) macroinitiator, poly(VPi-b-St), poly(VA-b-St) were characterized by GPC, FT-IR and1H-NMR. And the analysis showed that integrity of the block copolymer was maintained during saponification reaction.