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Extended mechanistic description of particle growth in electrosterically stabilized emulsion polymerization systems
journal contribution
posted on 2023-05-18, 08:45 authored by Stuart ThickettStuart Thickett, Gaborieau, M, Gilbert, RGPolymeric (steric and electrosteric) stabilizers, based on water-soluble polymers such as poly(acrylic acid) and poly(ethylene oxide), are widely used to make surface coatings by emulsion polymerization and form a “hairy layer” which provides colloidal stability to the latex particles. It is shown by a combination of NMR and rate studies that the growth of these polymer colloids is dominated by a hitherto unsuspected combination of mechanisms: an abstraction reaction in the “hairy layer” which results in a radical on the water-soluble polymer which is slow to propagate but quick to terminate (Macromolecules 2006, 39, 6495−6504) and can also undergo β-scission reactions. Termination with radicals which would otherwise lead to particle growth leads to radical loss, i.e., a slower polymerization rate, while β-scission leads to radicals which can enter the water phase and cause secondary particle formation. Both of these effects are undesirable from a manufacturing point of view, and the newly discovered mechanism could be used to mitigate these undesirable features.
History
Publication title
MacromoleculesVolume
40Issue
13Pagination
4710-4720ISSN
0024-9297Department/School
School of Natural SciencesPublisher
Amer Chemical SocPlace of publication
1155 16Th St, Nw, Washington, USA, Dc, 20036Rights statement
Copyright 2007 American Chemical SocietyRepository Status
- Restricted