Polymerization of chemically-activated monomers
where X is a symbol of some medium particle interacting with monomer molecules, with active centres of propagating chains and with monomer units of polymer formed, i, j and k 0. The chemical interaction of the monomer with particles of the medium may result in an increase of absolute conversion rate or, in the case of several possible paths of polymerization, in relative acceleration of one of them. Such a phenomenon is called chemical activation and the corresponding monomer is said to be chemically activated. The chemical activation may arise from (1) electron density redistribution on intramolecular bonds caused by interaction between M and X; let us call this intramolecular effect; (2) change of the character of intermolecular bonds between monomer species followed by change of their distribution and orientation (for instance formation of organized aggregates favourable for chain propagation); let us call this intermolecular effect. The presence of the X particles interacting with the monomer in reaction system often influences the monomer reactivity. Also the addition of the monomer molecule bonded with X (to initial active centre) may lead to the formation of a new active centre which also can attract X. Hence the possibility arises of propagating species reactivity change (for instance of their activation). In some cases it may even lead to polymerization mechanisms which are not typical for a given monomer in relatively inert media. Finally, the interaction between X, a monomer kind monomer units of a polymer may noticeably affect free energy of polymerization. Indeed if the