Three Different β-Cyclodextrins Direct the Emulsion Copolymerization of a Highly Fluorinated Methacrylate Toward Distinctive Nanostructured Particle Morphologies

Stable colloidal dispersions of nanostructured semi-fluorinated acrylic particles with an unfluorinated core and an outer layer consisting of copolymers of the highly hydrophobic and lipophobic heptadecafluorodecyl methacrylate (FMA) were successfully synthesized with the assistance of three different cyclodextrins as phase-transfer catalysts: beta-cyclodextrin (beta-CD), hydroxypropyl beta-cyclodextrin (HpCD), and methyl beta-cyclodextrin (MeCD). While all the cyclodextrins form a stable inclusion complex (IC) with FMA, only the ICs with the more hydrophilic HpCD and MeCD are soluble in water. Nevertheless, incorporation of FMA in the particle shell copolymer could be achieved also when using beta-CD. On the other hand, the morphology of the nanostructured particles was characterized by a patchy fluorinated shell dependent on the cyclodextrin used, the best results being obtained with MeCD. A monomer-starved semicontinuous emulsion polymerization procedure was essential to favor the CD-mediated incorporation of FMA into the copolymer structure and to achieve a stable colloidal dispersion even in the presence of small amounts of mixed anionic-nonionic surfactants. The thermal and surface properties of the latex films showed a good correlation with the shell composition and patchy nanostructured morphology of the particles. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 4518-4530, 2011