Elementary reactions of the emulsions polymerization of styrene with the localization of radical formation acts at the interface

• Published in: Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 1987-01, Vol.25 (1), p.47-62
• Main Authors: Ivanchev, S. S., Pavljuchenko, V. N., Byrdina, N. A.
• Format: Article
• Language: English
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.1987.080250106

The localization of radical formation acts at the interface achieved by the application of specially prepared surfactant initiators, fixation of initiating sites on the surface of seed latex particles by covalent bonds, or by redox initiating systems were experimentally studies. It is ascertained that the fixation of the initiator of polymerization at the interface of the emulsion system brings about a change of the kinetic parameters of its decomposition—an increase in the decomposition rate and decrease in the initiation efficiency. The experiments (measurements of chain propagation rate) demonstrated that the nature of emulsifying agent and initiator has no effect on the chain propagation acts. The kinetics of the chain termination depends on the properties of the emulsion system that is revealed in the dependence of chain termination constants on the type of initiator and the diameter of latex particles. These effects are supposed to be explained by influence of the colloid and chemical parameters of the reaction system on the conformation entropy of the growing macroradicals; and the low values of the chain termination constants (102–104 L mol−1 s−1) are due to the higher activation energy of chain termination for the emulsion polymerization.