Forces Driving the Development of Particle Morphology of Waterborne Polymer Dispersions

Abstract

[EN] Particle morphology is a key characteristic of the waterborne polymer dispersions and plenty of effort has been dedicated to understand the mechanisms controlling the development of the morphology during polymerization. The availability of new characterization techniques that provide unprecedented quantitative details of the particle morphology have questioned the ideas about the driving forces ruling the development of the morphology. In this article, the case is considered of a seeded emulsion polymerization in which the second stage polymer (Polymer 2) is more hydrophobic than the seed polymer and a water-soluble initiator is used. Simulations of the effect of the different forces involved in the formation of the particle morphology carried by integrating the Navier-Stokes are compared with available experimental results. If is found that the interfacial tensions are responsible for the penetration of clusters of polymer 2 within the seed polymer and the spread of these clusters over the surface of the particle. On the other hand, van der Waals forces control coalescence of the clusters both at the surface and in the interior of the particle.