Controlled radical polymerization of methacrylates at ambient temperature and the synthesis of block copolymers containing methacrylates

The controlled radical polymerization of methyl methacrylate (MMA) and 2-hy droxy ethyl methacrylate (HEMA) were successfully performed at ambient temp erature. MMA was polymerized in acetonitrile with ethyl-2-bromopropionate ( EPN-Br)/CuCl/2, 2'-bipyridyl (bpy) at 40 degrees C. The final polymer was w ith a narrow molecular weight distribution (M-w/M-n < 1.5) and controllable molecular weight. The controllable nature might have been contributed main ly by the high value of dielectric constant of acetonitrile. The bulk polym erization of HEMA, a monomer with a high value of dielectronic constant, ca n be well controlled with EPN-Br/CuCl/ bpy at 20 degrees C. The halogen ter minated PMMA and PSt were then used as macroinitiators to copolymerize with some other monomers. As a result, some block copolymers, such as PMMA-b-PS t, PMMA-b-PHEMA and PSt-b-PHEMA, were synthesized. (C) 1999 Elsevier Scienc e Ltd. All rights reserved.