Highly Efficient Cobalt-Mediated Radical Polymerization of Vinyl Acetate

摘要

In the last decades, rapidly increasing attention has been paid to so-called macromolecular engineering, that is, the synthesis of novel polymeric materials with well-defined molecular parameters. In this respect, controlled radical polymerization (CRP) proved to be a suitable strategy, because of its mild experimental conditions and tolerance to water. Nowadays, nitroxide-mediated polymerization (NMP),[1] atom-transfer radical polymerization (ATRP),[2] and radical addition-fragmentation chain-transfer (RAFT)[3] are among the more popular CRP techniques. All of them rely on the same concept, which consists of decreasing the radical concentration in the medium and thus the probability of irreversible termination. This is achieved by reversible conversion of the growing macroradicals P. to dormant species PX. The persistent-radical effect (PRE) is the origin of the high propensity of the radicals to undergo reversible deactivation rather than self-coupling reactions.