New Nitroxide Mediators for Controlled Synthesis of Polystyrene, Poly(meth)acrylates and Their Copolymers

摘要

Two different approaches to the realization of SFRP in the presence of nitroxides, namely, the introduction of stable radicals of different structure from outside, or their in situ generation in a polymerization of vinyl and (meth)acrylic monomers have been analyzed. First it has been ascertained that nitroxide derivatives of imidazole and piperidine are efficient agents of living polymerization of styrene. The synthesis of polymers with low polydispersity indexes (1.2_1.4) and predicted molecular weight has been performed in a temperature range of 80-130°C. The most efficient approach for polymerization of vinyl monomers is in-situ generation of stable radicals from nitrones and nitroso compounds. This approach allows realization of the controlled macromolecular synthesis at relatively low temperatures (50-70°C) and utilization of a variety of monomers able to be polymerized via SFRP mechanism. Quantum-chemical modeling of the processes has been performed.