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Synthesis of Well Defined Polymers by Radical Polymerization
CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF CHEMISTRY
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Several approaches to synthesis of polymers with controlled molecular weights, desired end groups and low polydispersities, by controlled radical polymerization are discussed. The first one is based on nitroxyl radicals such as TEMPO which can react reversibly with propagating radicals. The position of the equilibrium constant depends on the nature of the radical, solvent and temperature. Polymerization rates in systems involving polar monomers methyl methacrylate, methyl acrylate, vinyl acetate are higher than in systems based on non-polar monomers styrene. Other systems involve persistent organometallic-based radicals or hypercoordinated organic radicals as dormant species, in equilibrium with propagating macroradicals.
APPROVED FOR PUBLIC RELEASE