The influence of mixed solvent cyclohexanone-methyl methacrylate on the course of methyl methacrylate polymerization

Abstract The polymerization of MMA in cyclohexanone confirms the hypothesis that the rate constant of termination is influenced by the diffusion of macromolecular segments, taking place before the translation motion has been restricted. Therefore it is necessary to distinguish between local viscosity (or microviscosity) and the bulk viscosity of the system and their effects on the termination of radicals. If the polymerization of MMA takes place in cyclohexanone at 25° and the PMMA radicals are preferentially solvated by cyclohexanone, the rate of the growth reaction is determined by the concentration of monomer in the solvating layer while the termination is influenced by the viscosity corresponding to the composition of the mixed solvent in this layer.