Synthesis of poly(methyl methacrylate)-b-polystyrene containing a crown ether unit at the junction point via combination of atom transfer radical polymerization and nitroxide mediated radical polymerization routes

Altintas O., Yilmaz I., HIZAL G., TUNCA U.

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, vol.44, no.10, pp.3242-3249, 2006 (SCI-Expanded) identifier identifier


Poly(methyl methacrylate)-b-polystyrene (PMMA-b-PS) containing a benzo-15-crown-5 unit at the junction point was prepared by combining atom transfer radical polymerization and nitroxide-mediated radical polymerization. For this purpose, 6,7,9,10,12,13,15,16-octahydro-5,8,11,14,17-pentaoxa-benzocyclopentadecene-2-carboxylic acid 3-(2-bromo-2-methyl-propionyloxy)-2-methyl-2-[2-phenyl-2-(2,2,6,6-tetramethylpiperidin-1-yloxy)-ethoxycarbonyll-propyl ester (3) was synthesized and used as an initiator in atom transfer radical polymerization of methyl methacrylate in the presence of CuCl and pentamethyldiethylenetriamine at 60 degrees C. A linear behavior was observed in both plots of ln([M](0)/[MI]) versus time and M-N,M-GPC versus conversion indicating that the polymerization proceeded in a controlled/living manner. Thus obtained PMMA precursor was used as a macroinitiator in nitroxide-mediated radical polymerization of styrene (St) at 125 degrees C to give well-defined PMMA-b-PS with crown ether per chain. Kinetic data were also obtained for copolymerization. Moreover, potassium picrate (K+ picrate) complexation of 3 and PMMA-b-PS copolymer was studied.