Degenerative transfer and reversible termination mechanisms for living radical polymerizations mediated by cobalt porphyrins
Journal
Macromolecules
Journal Volume
39
Journal Issue
24
Pages
8219-8222
Date Issued
2006
Author(s)
Abstract
The living radical polymerization of acrylates by both degenerative transfer (DT) and reversible termination (RT) pathways with organo-cobalt porphyrin complexes as a dormant complex and latent source of radicals, was illustrated. Quais-equilibria between freely diffusing radicals and a dormant complex provides a constant low concentration of propagating radicals in solution which declines as radical termination occurs. Control of the radical concentration by the dormant complex attributes to the living character for reversible termination processes through the suppression of biomolecular radical termination relative to polymer propagation by the persistent radical effect (PRE). Degenerative transfer reaction is usually depicted as an associative process, exchange of active and latent radicals can be accomplished by a two-step dissociative process.
Other Subjects
Degenerative transfer (DT);Persistent radical effect (PRE);Polymer propagation;Transfer reaction;Cobalt;Complexation;Dissociation;Living polymerization;Reaction kinetics;Acrylics
Type
journal article