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-hydroxy ethyl methacrylate (HEMA) were successfully performed at ambient temperature. MMA was polymerized in acetonitrile with ethyl-2-bromopropionate (EPN-Br)/CuCl/2, 2'-bipyridyl (bpy) at 40 degrees C. The final polymer was with a narrow molecular weight distribution (M-w/M-n < 1.5) and controllable molecular weight. The controllable nature might have been contributed mainly by the high value of dielectric constant of acetonitrile. The bulk polymerization of HEMA, a monomer with a high value of dielectronic constant, can be well controlled with EPN-Br/CuCl/ bpy at 20 degrees C. The halogen terminated PMMA and PSt were then used as macroinitiators to copolymerize with some other monomers. As a result, some block copolymers, such as PMMA-b-PSt, PMMA-b-PHEMA and PSt-b-PHEMA, were synthesized. (C) 1999 Elsevier Science Ltd. All rights reserved.