Quantitative theory of free-radical copolymerization allowing for the phenomenon of preferential sorption

A number of anomalies, found in studies on the free-radical copolymerizations of a variety of monomers are attributed to the globular state of growing macroradicals, the monomer mixture composition inside and outside of which differ markedly. An account of such partitioning of monomers (the Harwood Bootstrap Effect) is performed within the framework of a new quantitative theory of copolymerization which interprets the dependence of the composition of copolymers obtained at low conversions on their molecular weights, as well as explains the pronounced intramolecular and compositional inhomogeneity of these copolymers. A theoretical approach has been elaborated to describe the copolymerization of an arbitrary number of monomers which is easy to verify experimentally because along with reactivity ratios its only other input parameters are the Flory chi-parameters of pair interactions between monomer units, monomers, and solvent molecules.