Atom transfer radical polymerization of cyclohexyl methacrylate at a low temperature

The atom transfer radical polymerization of cyclohexyl methacrylate (CHMA) is reported. Controlled polymerizations were performed with the CuBr/ N,N,N',N",N"-pentamethyldiethylenetriamine catalytic system with ethyl 2-bromoisobutyrate as the initiator in bulk and different solvents (25 vol %) at 40degreesC. The polymerization of CHMA in bulk resulted in a controlled polymerization, although the concentration of active species was relatively elevated. The addition of a solvent was necessary to reduce the polymerization rate, which was dependent on the dipole moment. Well-controlled polymers were obtained in toluene, diphenyl ether, and benzonitrile solutions. Poly(cyclohexyl methacrylate) as a macroinitiator was used to synthesize the poly(cyclohexyl methacrylate)-b-poly(tert-butyl methacrylate) block copolymer, which allowed a demonstration of its living character. In addition, two difunctional initiators, 1,4-bis(bromoisobutyryloxy) benzene and 1,2-bis(bromoisobutyryloxy) ethane, were used to initiate the atom transfer radical polymerization of CHMA. The experimental molecular weights of the obtained polymers were very close to the theoretical ones. These, along with the relative narrow molecular weight distributions, indicated that the polymerization was living and controlled. For confirmation, two different poly(tert-butyl methacrylate)-b-poly(cyclohexyl methacrylate)-b-poly(tert-butyl methacrylate) triblock copolymers were also synthesized. (C) 2004 Wiley Periodicals, Inc.