Modeling of Emulsion Polymerization, Will It Ever be Possible ? Part‐2: Determination of Basic Kinetic Data Over the Last Ten Years

Abstract

Summary: Modeling of Emulsion polymerization processes is based on the knowledge of fundamental kinetic and thermodynamic parameters. The most important kinetic parameters are propagation and termination rate coefficients. Ten years ago a paper has been published with the title ''Modeling of Emulsion Polymerization, will it ever be possible?''. The paper expresses serious doubts whether the different kinetic parameters will ever be available for general industrial recipes containing several monomers. In this paper the developments in the last 10 years regarding pulsed initiation polymerization (PIP) and other techniques regarding the determination of especially the kinetic parameters will be discussed. Amongst the areas where progress can be seen is the understanding of acrylate systems and water soluble monomers. New techniques like MALDI-ToF MS and time resolved electron spin resonance have strongly contributed to the area. Also the puzzling effect of chain length dependent propagation is discussed. Finally an answer will be given to the title question.

The Impact of Band Broadening on Molar‐Mass Determination of Narrow‐Distribution Polymer by Size‐Exclusion Chromatography

“…[11] Note that the determined Gaussian broadening is very weak for the standard with the lowest molar mass and hence highest V e , which does not agree with the theory and lacks any adequate interpretation for now. However, analogous effects were observed for low-molar-mass standards in other studies, [19] whereupon an SEC-derived and a Poisson-…”

“…One is an experimental determination that BB seemingly increases with increasing M peak of polymer standards. [19] As already explained, this makes no sense in terms of s G , as larger polymer has faster residence time in an SEC instrument. However, the work here has shown that t is the more influential broadening parameter, and indeed it should increase in value as mass becomes larger and there is weaker averaging of radial positions due to shorter duration inside the columns and lower diffusion coefficients.…”

“…It is worth mentioning that this effect can also be involved in the finding that BB seemingly increases with increasing M peak of polymer standards. [19] In this context, it is important to be aware that a linear or almost linear shape of the calibration function only works with molar masses given on a logarithmic scale. As the same extent of broadening in an elution chromatogram covers a wider range of molar masses, BB seems to be more pronounced for high molarmass polymers in MMDs with a linear molar-mass scale than it does for low molar-mass polymers.…”

Modeling of Emulsion Copolymerizations Will it Ever be Possible? Part III Conclusion

“…Finally in process control polymerization models are often an integral part of the control system. The discussion on the possibilities of modeling emulsion (co)polymerization has been summarized periodically in the first two papers in this series 1,2 A comprehensive description of the emulsion (co)polymerization process can be found in the book of Gilbert 3 . Recently an addendum in the form of a State of the Art article was published 4 .…”

“…In the production of latex particles almost exclusively the emulsion copolymerization technique is used. In understanding the properties of these latex particles the understanding of the formation of the chains and the particles is of crucial importance 1,2 . Modeling emulsion polymerization is important for this understanding but the purpose of modeling emulsion copolymerizations can be manifold.…”