A novel macroinitiator for the synthesis of triblock copolymers via atom transfer radical polymerization: Polystyrene-block-poly(bisphenol A carbonate)-block-polystyrene and poly(methyl methacrylate)-block-poly(bisphenol A carbonate)-block-poly(methy

摘要

Bis(hydroxy)telechelic bisphenol A polycarbonate (PC) was prepared via melt polycondensation of bisphenol A (BPA) and dipheryl carbonate (DPC) using lanthanum(in) acetylacetonate as a catalyst for transesterification. Subsequently, the polycarbonate was converted to a bifunctional macroinitiator for atom transfer radical polymerization (ATRP) with the reagent, alpha-chlorophenylacetyl chloride. The macroinitiator was used for the polymerization of styrene (S) and methyl methacrylate (MMA) to give PS-block-PC-block-PS and PMMA-block-PC-block-PMMA triblock copolymers. These block copolymers were characterized by NMR and GPC. When styrene and methyl methacrylate were used in large excess, significant shifts toward high molecular weights were observed with quantitative consumption of the macroinitiator. Several ligands were studied in combination with CuCl as the ATRP catalyst. Kinetic studies reveal the controlled nature of the polymerization reaction for all the ligands used.[GRAPHICS]Formation of a bifunctional ATRP macroinitiator by esterification of bis(hydroxy)telechelic PC with alpha-chlorophenylacetyl chloride.