<< Living >> chain radical polymerisation

Various types of substances used successfully as agents of "living" radical polymerisation, for example, alkoxyamines, the products of addition of cha in carriers R-. to stable nitroxides, products of the reaction between thes e radicals and transition metal complexes with different organic ligands, e tc. In all cases; the mechanism of action of these agents consists in rever sible dissociation A reversible arrow R-. + X-., where X-. is a substance ( stable free radical or metal-containing complex), able to compete in accept ing the R-. radicals (R-. + X-. --> A) with quadratic chain termination. pa rticular attention is paid to the studies which allowed formulation of the mechanism of "living" radical polymerisation at a quantitative level as a m athematical model suitable for predicting both the parameters of the polyme risation and the properties of the resulting polymer (molecular mass and po lydispersity).