Free-radical polymerization in a droplet with initiation at the interface

• Published in: European polymer journal Vol. 190; p. 112002
• Main Authors: Roshchin, D.E., Patlazhan, S.A., Berlin, A.A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 25.05.2023
• Subjects: Droplet; Free radical polymerization; Reaction-diffusion system; Droplet; Free radical polymerization; Reaction-diffusion system
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2023.112002

[Display omitted] •Two regimes of polymerization for different droplet radii are revealed.•Average chain length and dispersity are sensitive to droplet size.•Micron-sized droplets allow controllable formation of oligomer molecules. The free-radical polymerization inside monomer droplets surrounded by an immiscible liquid of the initiator solution is studied before the gel effect by means of the generalized method of moments taking into account diffusion of radicals and polymer chains. The influence of the droplet radius and initiator concentration in the surrounding phase on the polymerization kinetics and molecular mass characteristics of the synthesized polymer is analyzed. It is found that the polymerization kinetics matches the bulk polymerization when the droplet is small enough (kinetic regime). However, increasing the droplet radius leads to a diffusion-kinetic regime, in which the polymerization rate becomes significantly lower. As a result, the average length and the dispersity of the produced polymer chains depend significantly on the monomer droplet size. The dependence of the effective polymerization rate coefficient on the droplet radius and the initiator concentration is discussed.