ON THE GENERALIZED DESCRIPTION OF THE RAT E-CONSTANT OF BIRADICAL TERMINATION IN FREE-RADICAL POLYMERIZATION OF ALKYL METHACRYLATE AND STYRENE

An approach is developed for the description of the change of the rate constant of termination in the stage of gel effect. The approach is b ased on the ideas of diffusion motion of macromolecules in concentrate d polymer solutions and takes into account the ''indirect cage effect' ' which manifests itself by the appearance of steric retardations in f ast chemical reactions. Quantitative expressions relating the gel effe ct with the rate of segmental diffusion, polymer concentration, molar masses of the polymer and the reacting radicals, and steric retardatio ns for termination are obtained. The approach suggested enables unders tanding of the gel effect in polymerization of alkyl methacrylate and styrene.