Journal of Polymer Science Part A: Polymer Chemistry, Vol.43, No.24, 6247-6261, 2005
Solvent effect on the atom transfer radical polymerization of allyl methacrylate
The controlled radical polymerization of allyl methacrylate by atom transfer radical polymerization was carried out in solution at 70 degrees C, with ethyl 2-bromoisobutyrate as the initiator and copper halide (CuX, where X is Cl or Br) with N,N,N',N",N"-pentamethyldiethylenetriamine as the catalyst system. Kinetic analyses demonstrated that all the homopolymerization reactions showed a general behavior characterized by two clearly differentiated stages. Thus, in the early stage, the conversion increased continually with the time, independently of the solvent employed. In the second stage, a deceleration process took place, and a limit conversion was achieved, depending on the polarity and amount of the solvent used. The dependence of both the gel formation and limit conversion, as well as the molecular characteristics of poly(allyl methacrylate)s formed with different experimental parameters, such as the initial monomer concentration, the solvent employed, and the type of halide used as a catalyst, was also examined. The prepared polymers were characterized by size exclusion chromatography, Fourier transform infrared, and one-and two-dimensional nuclear magnetic resonance spectroscopy. Moreover, chain-growth experiments with butyl acrylate as the comonomer proved the living character of the poly(allyl methacrylate)s obtained, with these used as macroinitiators. (c) 2005 Wiley Periodicals, Inc.
Keywords:allyl methacrylate (AMA);atom transfer radical polymerization (ATRP);diblock copolymers;gelation;solvent effect