Preparation of polymer particles in nonaqueous direct and inverse miniemulsions

Citation
K. Landfester et al., Preparation of polymer particles in nonaqueous direct and inverse miniemulsions, MACROMOLEC, 33(7), 2000, pp. 2370-2376
Citations number
21
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
MACROMOLECULES
ISSN journal
00249297 → ACNP
Volume
33
Issue
7
Year of publication
2000
Pages
2370 - 2376
Database
ISI
SICI code
0024-9297(20000404)33:7<2370:POPPIN>2.0.ZU;2-H
Abstract
Polymerizable miniemulsions were formulated in nonaqueous media, and it is shown that these systems exhibit characteristics similar to those of aqueou s miniemulsions. Depending on the polarity of the continuous medium and the dispersed phase, the formulation of direct and inverse miniemulsions is po ssible. Direct miniemulsions in nonaqueous media are exemplified by dispers ing styrene in formamide or glycol. Inverse miniemulsions were generated wi th the polar monomer hydroxyethyl methacrylate, acrylamide, or acrylic acid in cyclohexane or hexadecane as the unpolar continuous phase, and the mini emulsions were polymerized to latexes. For both the direct and inverse mini emulsions, it was shown that during high shear dispersion a steady state of droplet size is reached and that addition of a strong lipophobe (for inver se systems) or ultrahydrophobe (for regular systems) is required to stabili ze the resulting miniemulsion for sufficient times. With surface tension me asurements, the coverage of the particles with surfactant was determined to be incomplete. These facts are typical for the miniemulsion state; i.e., i t is proven that organic miniemulsions indeed can be made and polymerized.