Free-radical copolymerization of binary mixtures of vinyl monomers of various compositions: Initiation rate constants

Abstract

For a number of vinyl monomers (styrene, butyl acrylate, vinyl acetate, and methyl-, butyl-, and lauryl methacrylates) and their mixtures with a divinyl (network-forming) monomer—triethylene glycol dimethacrylate—with the molar ratio of binary mixture components varying from 0 to 100%, initiation rate constants have been measured through the inhibition method with the use of 2,2,6,6-tetramethyl-1-piperidinyloxy as a counter of free radicals. Viscosities at various temperatures and activation energies for the viscous flow of the monomers under study have been estimated. The relationship between the initiation rate constants and the viscosity of the medium has been established. On the basis of this relationship, the mechanism for the exit of radicals from the cage has been interpreted within the framework of the Franck-Rabinowitch model with allowance made for effects associated with formation of intermolecular associates in the systems under study.